1. INTRODUCTION 1

1. INTRODUCTION

1.1 MEDICINAL PLANTS: AN OVERVIEW

Medicinal plants contain inherent active ingredients to cure disease or relieve pain. The

use of traditional medicines and medicinal plant in most developing countries as

therapeutic agent for the maintenance of good health has been widely observed. The

world health organization estimated that 80% of the population of developing countries

relies on traditional medicines, mostly herbal plant drugs for their primary health care.

The medicinal property of plant could be based on the anti-oxidant, antimicrobial,

antipyretic effect of the phytochemicals present. Traditionally, herbs have been

considered to be non-toxic and have been used for treating various problems by the

general public and/or traditional medicine doctors worldwide. Although, the literature has

documented several toxicity resulted from the use of herbs on many occasions, still the

potential toxicity of herbs has not been recognized by the general public or by

professional groups of traditional medicine. The use of medicinal plants as raw materials

in the production of drug is gaining popularity.1,2

India perhaps the largest producer of medicinal herbs and is called Botanical Garden of

the World. Medicinal herbs have been in use for thousands of years, in one form or

another, under the indigenous systems of medicine like Ayurveda, Sidha and Unani. On

earth, around 3.6 lakh species of medicinal plants are present, among these 1.4 lakh

species are in India.. A latest survey indicates that about 70000 plants are used in

traditional systems of medicines.3 All over the world, plants were used as main source of

medicines by ancestors. The rise of modern western medicine was initially accompanied

by a decline in the practice of herbalism in all cultures and it was believed that synthetic

chemicals were best medicines to treat illness and cure disease.

The quest for a healthier lifestyle has made people to once again recognize the healing

power of herbs. Even in the west, natural products are now widely available and

1. INTRODUCTION 2

herbalism is again coming into lime light in the world which is becoming healthier and

environmentally conscious. Herbal remedies can work without many of the unpleasant

side effects of modern medicines.

A reversion has been observed towards traditional systems of medicine for better

treatment and care. People all over the world, in future will prefer treatment in the

traditional systems of medicine. The reason for this is that in spite of well-documented

facts regarding the efficacy of modern medicine, certain draw backs have restricted its

future prospects. The disadvantages of modern medicine have led the researchers to look

for alternative systems especially the ancient and traditional medicine.4

1.1.1 Traditional Medicine

The term “traditional medicine” refers to ways of protecting and restoring health that

existed before the arrival of modern medicine. As the term implies, these approaches to

health belong to each country, and have been handed down from generation to

generation. A traditional system requires to meet the needs of the local communities for

many centuries. The traditional system of medicine is prevalent in India since the Vedic

period and as early as the dawn of human civilization. Though it has undergone many

changes in the course of its long history, it still remains the main history of medical relief

to a large section of population of the nation. Traditional medicine has maintained its

popularity in a number of Asian countries such as China, India, Japan and Pakistan.

Medicinal plants are the oldest known health care products. Their importance is still

growing.5

Ayurveda- An Indian system of medicine

Ayurveda ancient sciences of life are believed to be prevalent for the last 5000 years in

India. It is one of the most noted systems of medicine in the world. Ayurveda is based on

the hypothesis that everything in the universe is composed of five basic elements viz.

space, air, energy, liquid and solid. They exist in the human body in confined forms like

vata(space and air), pitta(energy and liquid) and kapha(liquid and solid). Vata, pitta and

kapha together are called tridosha (three pillars of life) .Imbalance in between these will

cause pathological condition.6

1. INTRODUCTION 3

Unani systems of medicine

The roots of this system go deep to the times of the well known Greek philosopher

Hippocrates who is credited with it. Aristotle Golem “Father of natural history” made

valuable contribution to it. This system is based on two theories viz. Hippocratic theory

of four humours and the Pythagorian theory of four proximate qualities. The four

humours are blood, phlegm, yellow bile and black bile while the four qualities are the

states of living human body like hot. cold, moist and dry. They are represented as earth,

water, fire and air. The Unani system of medicine aims at treating the cause of disease

and not its symptoms. For this purpose, thorough history of the patient is recorded in

addition to his pulse, urine and stool examinations. The diseased condition is considered

to be the imbalance between humours and accordingly, treatment is given.6

Homoeopathic system of medicine

In comparison to other traditional systems of medicine, homoeopathy is a newer one and

has been developed in the eighteenth century by Samuel Hahnemann – a German

physician and Chemist. He proposed that the cause of disease itself could be used for its

treatment. He put forth the law of similarities which says that “like cures like”. With this

principle, he showed that cinchona can produce the symptoms of malaria. He complied

all these observations in what is called “The organon of medicine”.

In the homoeopathic system, the treatment is not specified but the choice of drug depends

on symptoms and the clinical condition of the patient. This is based on the concept of

proving and prover. In a healthy person called prover, the symptoms created by different

doses of drug extracts are noted which is called proving and if physical, mental and

emotional changes of prover are specifically considered. Consequently, these symptoms

are composed with a patient with similar symptoms and accordingly, same type of extract

is given for treatment. Various medicinal plants used in Homeopathic system are Arnica,

Belladona, Chamomile, Colchicum, Hyocyamus, Ipecacuhna, Lycopodium, Opium,

Ergot, Nux-vomica etc.6

Siddha system of medicine

The term “Siddha” means achievement and “Siddhars” were saintly personalities, who

attained proficiency in medicine through practice of Bhakti and Yoga. This is the system

of pre-vedic period identified with Dravidian culture and it is largely therapeutic in

1. INTRODUCTION 4

nature. Like Ayurveda, this system believes that all objects in universe are made up of

five basic elements namely earth, water, sky, fire and air. The identification of causative

factors of disease is done through pulse reading, colour of body, study of voice, urine

examination, status of digestive system and examination of tongue.6

Naturopathy and Yoga

Naturopathy is not merely a system of treatment, but also a way of life, which is based on

laws of nature. The attention is particularly paid to eating and living habits, adoption of

purificatory measures, use of hydrotherapy, mud packs, baths, massage etc.

Yoga is a science as well an art of healthy living physically, mentally, morally and

spiritually. Its systematic growth from animal level to the normal, from there to the

divinity ultimately. The eight components of Yoga are restraint, observance of austerity,

physical postures, restraining of sense organs, breathing exercises, contemplation,

meditation and Samadhi.6

1.1.2 Herbal medicine today

Today herbal medicine has just improved ancient secrets and brought them on the market.

Many people turned to herbal medicine because they simply were disappointed with

traditional medicine or surgery. Herbal remedies are still relatively popular today, mainly

due to the fact that they are regarded as harmless because they are natural.

Rather than using a whole plant, pharmacologists identify, isolate, extract, and synthesize

individual components, thus capturing the active principles. In addition to active

ingredients, plants contain minerals, vitamins, volatile oils, glycosides, alkaloids,

bioflavonoid, and other substances that are important in supporting a particular herb's

medicinal properties. These elements also provide an important natural safeguard isolated

or synthesized active compounds can become toxic in relatively small doses; it usually

takes a much greater amount of a whole herb, with all of its components, to reach a toxic

level. Herbs are medicines, however, and they can have powerful effects. They should

not be taken lightly.

The efficacy of many medicinal plants has been validated by scientists abroad, from

Europe to the Orient. Thanks to modern technology, science can now identify some of the

specific properties and interactions of botanical constituents. With this scientific

documentation, we now know why certain herbs are effective against certain conditions.

1. INTRODUCTION 5

However, almost all of the current research validating herbal medicine has been done in

Germany, Japan, China, Taiwan, and Russia. And for the most part, the United States

Food and Drug Administration (FDA), which is responsible for licensing all new drugs

(or any substances for which medicinal properties are claimed) for use in the United

States, does not recognize or accept findings from across the sea. Doctors and

government agencies want to see American scientific studies before recognizing the

effectiveness of a plant as medicine. Yet even though substantial research is being done

in other countries, drug companies and laboratories in the United States so far have not

chosen to put much money or resources into botanical research. The result is that herbal

medicine does not have the same place of importance or level of acceptance in this

country as it does in other countries.7

1.1.3 Approach to drug discovery from plants

There are many approaches to the search for new biologically active principles in higher

plants. One can simply look for new chemical constitution and hope to find a biologist

who is willing to test each substance with whatever pharmacological tests available.

A second approach is simply to collect every readily available plant, prepare extract and

test each extract for one (or) more types of pharmacological activity. This random

collection, broad screening method is a reasonable approach that eventually should

produce useful drugs, but it is contingent as the availability of adequate findings and

appropriate predictable bioassay systems.4

1.1.4 Advantage of herbal medicines

There are a number advantages associated with using herbal medicines as opposed to

pharmaceutical products. Examples include the following:

Reduced risk of side effects: Most herbal medicines are well tolerated by the patient,

with fewer unintended consequences than pharmaceutical drugs. Herbs typically have

fewer side effects than traditional medicine, and may be safer to use over time.

Effectives with chronic conditions: Herbal medicines tend to be more effective for long-

standing health complaints that don't respond well to traditional medicine. One example

is the herbs and alternative remedies used to treat arthritis. Vioxx, a well-known

prescription drug used to treat arthritis, was recalled due to increased risk of

cardiovascular complications. Alternative treatments for arthritis, on the other hand, have

1. INTRODUCTION 6

few side effects. Such treatments include dietary changes like adding simple herbs,

eliminating vegetables from the nightshade family and reducing white sugar

consumption.

Lower cost: Another advantage to herbal medicine is cost. Herbs cost much less than

prescription medications. Research, testing, and marketing add considerably to the cost of

prescription medicines. Herbs tend to be inexpensive compared to drugs.

Widespread availability: Yet another advantage of herbal medicines are their

availability. Herbs are available without a prescription. You can grow some simple herbs,

such as peppermint and chamomile, at home. In some remote parts of the world, herbs

may be the only treatment available to the majority of people.4,7

1.1.5 Comparison of Herbal and Conventional Medicine

Conventional medications have a downside; many can cause harmful side effects and

only serve to lessen the symptoms instead of treat the root problem. Furthermore, many

conventional medicines are based on single compounds that bacteria become resistant to

over time. Herbal remedies, on the other hand, are comprised of complex compounds that

are difficult for bacteria to metabolize and use for colonization. Natural remedies have

the benefit of being non-toxic and devoid of side effects. They are also effective in

treating the sickness as well as the root cause of the condition. Along with these

important advantages, herbal medicines can boost immunity and enhance the body’s

defenses and natural ability to combat the invasion of foreign pathogens.

Many herbs, such as goldenseal and garlic, have natural antibiotic and antiviral properties

as well. Licorice soothes the throat, ginger prevents blood clots and lessens the risk of

heart disease and herbal teas help reduce tension. There are herbs that can address

respiratory, gastrointestinal, neurological and sexual problems as well. In many cases

natural herbal remedies can even help in managing the side effects of aggressive

treatments like chemotherapy. In summary, there is much to gain from the use of natural

remedies. They offer a safe and natural alternative to conventional medicine and are often

times more effective.8

1.1.6 Worldwide herbal trade

People are using herbal medicines from centuries for safety, efficacy, cultural

acceptability and lesser side effects. Plant and plant products have been utilized with

1. INTRODUCTION 7

varying success to cure and prevent diseases throughout history. Written records about

medicinal plants date back at least 5000 years to the Sumerians and ancient records have

suggested earlier use of medicinal plants. Due to side effects of synthetic products, herbal

products are gaining popularity in the world market. In spite of well-practiced knowledge

of herbal medicine and occurrence of a large number of medicinal plants, the share of

India in the global market is not up to the mark. The utilization of herbal drugs is on the

flow and the market is growing step by step .The annual turnover of the Indian herbal

medicinal industry is about Rs. 2,300 crore as against the pharmaceutical industry’s

turnover of Rs. 14,500 crores with a growth rate of 15 percent. The export of medicinal

plants and herbs from India has been quite substantial in the last few years. India is the

second largest producer of castor seeds in the world, producing about 1,25,000 tones per

annum.9

1.1.7 Relationship between man and herbs

Medicinal plants have been a major source of cure of human diseases since time

immemorial. Today, one fourth of the world population depends on traditional medicines.

Despite the introduction of antibiotics since the 1940's, even 80 per cent of the population

today relies on indigenous medicinal plants and the drugs. It is estimated that the global

traditional medicine market is growing at the rate of 7 - 15 per cent annually. The

medicinal plant value is about Rs.5000 crores in India and it is estimated that the country

exports about Rs.550 crore worth of herbal drugs but with the rich and diverse botanical

resources in our country, this is not an impressive export performance considering the

worldwide herbal market worth US 60 billion dollars. It is also necessary to integrate

modern knowledge with traditional knowledge. The drugs and products of the industry

are working on the scientifically defined techniques and explained with modern

biological and chemical definitions and tools, and that alone will give a therapeutically

active herbal original drug available for health care worldwide.9

The ayurvedic drug manufacturers in Kerala with the state government and central

assistance is putting up a Rs.62.5 crore company to set up a world standard QC lab, R&D

facility for the industrial benefit with all the modern equipment for advanced drug

standardization, quality and efficacy. This will also develop own protocols of quality

certification equivalent to other global standards.10

1. INTRODUCTION 8

1.1.8 Herbal medicine for market potential

The global market for herbal medicines currently stands at over $60 billion annually. The

sale of herbal medicines is expected to get higher at 6.4% an average annual growth rate.

Due to the contribution of numerous significant factors, the market of herbal medicines

has grown at an expressive rate worldwide. Some of them are preference of consumers

for natural therapies, growing concern regarding undesirable side effects of modern

medicines and the belief that herbal drugs are free from side effects, since millions of

people all over the world have been using herbal medicines for thousands of years; great

interest in alternative medicines; preference of populations for preventive medicine due

to increasing population age; the belief that herbal medicines might be of effective

benefit in the treatment of certain diseases where conventional therapies and medicines

have proven to be inadequate; tendency towards self-medication; improvement in quality,

proof of efficacy and safety of herbal medicines and high cost of synthetic medicines.

According to World Health Organization, herbal medicines are lucrative globally and

they represent a market value of about US$ 43 billion a year.

According to an estimate in 1991, the herbal medicine market in the European countries

was about $ 6 billion, with Germany accounting for $ 3 billion, France $ 1.6 billion and

Italy $ 0.6 billion while in other countries was 0.8 billion. In 1996, the herbal medicine

market in the European countries was about $ 10 billion, in USA about $ 4 million, in

India about $ 1.0 billion and in other countries was $ 5.0 billion. In 1997, the European

market alone reached about $ 7.0 billion. The German market corresponds to about 50%

of the European market, about $ 3.5 billion. This market is followed by France, $ 1.8

billion; Italy, $ 700 million;

The use of herbal remedies in the U.S. is widespread and increasing dramatically but the

physicians should have a good knowledge base and clear concept about herbal remedies

and should inquire about their use, discuss adverse effects, and monitor and identify

possible herb– drug interactions. There is a clear need for better public and physician

understanding of herbal products through health education, early detection and

management of herbal toxicities, scientific scrutiny of their use, and research on their

safety and effectiveness. Regulatory policies are also needed to protect people from

untoward effects on their health and finances.11

1. INTRODUCTION 9

1.1.9 Crude extract more potent than isolated chemical

Crud extract mixtures of plant are better than pure isolated chemicals. Several

biologically active compounds in a plant work together to produce greater effect then

single chemical on its own. The mixture of chemicals found in herbs can be more potent

than the single purified ingredient so beloved of drugs companies. Chemical partnerships

explain why whole herbs can work better than single purified ingredients. In other words,

the mixture has an effect greater than the sum of its parts. The synergism arises when two

or more factors interact in such a way that outcome is not additive but multiplicative. The

compound impact of the relationship can be so powerful that the result may be a whole

order of magnitude greater than the simple sum of the components. The observation

suggests that synergistic or antagonistic effect of various components of plant material in

its crude natural state may enhance therapeutic effects and reduce side effects, which may

not occur when one or more isolated chemical component are used alone in purified

forms. Synthesizing the bioactive ingredients would inevitably reduce or eliminate that

benefit. Anyway, herbal extract hopefully would delay resistance against diseases, while

bioactive principles can become our therapeutic armamentarium (Fig.1.1).

Figure 1.1: Crude extract more potent than isolated chemical

1. INTRODUCTION 10

Mechanism of synergic effect based on classical pharmacology, molecular biology and

clinical work can be divided into at least following four mechanisms:

1) Synergic multitarget effect: natural products affect not only one target, but several

targets and can cooperate in an agonistic and synergistic way

2) Pharmacokinetic and Physicochemical effect: natural products improve solubility

and /or the reabsorption rate and thereby the bioavailability.

3) Interference with the resistance mechanism of bacteria, natural product antagonizes

the resistance to antibiotics.

4) Elimination and neutralization effect, natural product by itself or after treatment

eliminate or neutralize within a drug preparation or in combination with synthetic

drug preparation adverse events, so that altogether effect improves.12

1.2 INFLAMMATION

Inflammation (Latin, inflammare, to set on fire) is part of the complex biological

response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or

irritants. Inflammation is a protective attempt by the organism to remove the injurious

stimuli and to initiate the healing process. Inflammation is not a synonym for infection,

even in cases where inflammation is caused by infection. Although infection is caused by

a microorganism, inflammation is one of the responses of the organism to the pathogen.

However, inflammation is a stereotyped response, and therefore it is considered as a

mechanism of innate immunity, as compared to adaptive immunity, which is specific for

each pathogen.13

Without inflammation, wounds and infections would never heal. Similarly, progressive

destruction of the tissue would compromise the survival of the organism. However,

chronic inflammation can also lead to a host of diseases, such as hay fever,

atherosclerosis, rheumatoid arthritis, and even cancer (e.g., gallbladder carcinoma). It is

for that reason that inflammation is normally closely regulated by the body.

Inflammation can be classified as either acute or chronic. Acute inflammation is the

initial response of the body to harmful stimuli and is achieved by the increased movement

of plasma and leukocytes (especially granulocytes ) from the blood into the injured

tissues. A cascade of biochemical events propagates and matures the inflammatory

response, involving the local vascular system, the immune system, and various cells

1. INTRODUCTION 11

within the injured tissue. Prolonged inflammation, known as chronic inflammation, leads

to a progressive shift in the type of cells present at the site of inflammation and is

characterized by simultaneous destruction and healing of the tissue from the

inflammatory process13

.

Causes14

Burns

Chemical irritants

Frostbite

Toxins

Infection by pathogens

Physical injury, blunt or penetrating

Immune reactions due to hypersensitivity

Ionizing radiation

Foreign bodies, including splinters, dirt and debris

Trauma

Cardinal signs

Acute inflammation is a short-term process, usually appearing within a few minutes or

hours and ceasing upon the removal of the injurious stimulus.14

It is characterized by five

cardinal signs: 15

The acronym that may be used for this is "PRISH" for Pain, Redness, Immobility (loss of

function), Swelling and Heat.

The traditional names for signs of inflammation come from Latin:

Dolor (pain)

Calor (heat)

Rubor (redness)

Tumor (swelling)

Functio laesa (loss of function)

The first four (classical signs) were described by Celsus (ca 30 BC–38 AD),16

while loss

of function was added later by Galen17

even though the attribution is disputed and the

origination of the fifth sign has also been ascribed to Thomas Sydenham18

and Virchow.

Redness and heat are due to increased blood flow at body core temperature to the

1. INTRODUCTION 12

inflamed site; swelling is caused by accumulation of fluid; pain is due to release of

chemicals that stimulate nerve endings. Loss of function has multiple causes.15

These five signs appear when acute inflammation occurs on the body's surface, whereas

acute inflammation of internal organs may not result in the full set. Pain only happens

where the appropriate sensory nerve endings exist in the inflamed area—e.g., acute

inflammation of the lung (pneumonia) does not cause pain unless the inflammation

involves the parietal pleura, which does have pain-sensitive nerve endings.15

1.2.1 Process of acute inflammation

The process of acute inflammation is initiated by cells already present in all tissues,

mainly resident macrophages, dendritic cells, histiocytes, kupffer cells and mastocytes.

These cells have present on their surfaces certain receptors named pattern recognition

receptors (PRRs), which recognize molecules that are broadly shared by pathogens but

distinguishable from host molecules, collectively referred to as pathogen-associated

molecular patterns (PAMPs). At the onset of an infection, burn, or other injuries, these

cells undergo activation (one of their PRRs recognize a PAMP) and release inflammatory

mediators responsible for the clinical signs of inflammation. Vaso dilation and the

resulting increased blood flow causes the redness (rubor) and increased heat (calor).

Increased permeability of the blood vessels results in an exudation (leakage) of plasma

proteins and fluid into the tissue (edema), which manifests itself as swelling (tumor).

Some of the released mediators such as bradykinin increase the sensitivity to pain

(hyperalgesia, dolor). The mediator molecules also alter the blood vessels to permit the

migration of leukocytes, mainly neutrophils, outside of the blood vessels (extravasation)

into the tissue. The neutrophils migrate along a chemotactic gradient created by the local

cells to reach the site of injury.14

The loss of function (functio laesa) is probably the

result of a neurological reflex in response to pain.

In addition to cell-derived mediators, several acellular biochemical cascade systems

consisting of preformed plasma proteins act in parallel to initiate and propagate the

inflammatory response. These include the complement system activated by bacteria, and

the coagulation and fibrinolysis systems activated by necrosis, e.g. a burn or a trauma.

The acute inflammatory response requires constant stimulation to be sustained.

1. INTRODUCTION 13

Inflammatory mediators have short half lives and are quickly degraded in the tissue.

Hence, acute inflammation ceases once the stimulus has been removed.14

Cyclooxygenase (COX)

COX is an enzyme that is responsible for formation of important biological mediators

called prostanoids,includingprostaglandins, prostacyclin and thromboxane.

Pharmacological inhibition of COX can provide relief from the symptoms of

inflammation and pain. Non-steroidal anti-inflammatory drug, such as aspirin and

ibuprofen, exert effects through inhibition of COX.

COX converts arachidonic acid (AA, an ω-6 PUFA) to prostaglandin H2(PGH2), the

precursor of the series-2 prostanoids. The enzyme contains two active sites:

a heme with peroxidase activity, responsible for the reduction of PGG2 to PGH2, and a

cyclooxygenase site, where arachidonic acid is converted into the hydroperoxy

endoperoxide prostaglandin G2(PGG2). The reaction proceeds through H atom abstraction

from arachidonic acid by a tyrosine radical generated by the peroxidase active site. Two

O2 molecules then react with the arachidonic acid radical, yielding PGG2.

At present, three COX isoenzymes are known: COX-1, COX-2, and COX-3.The COX-

3 is a splice variant of COX-1, which retains intron one and has aframeshift mutation;

thus some prefer the name COX-1b or COX-1 variant(COX-1v).The

main COX inhibitors are the non-steroidal anti-inflammatory drugs (NSAIDs).

The classical COX inhibitors are not selective and inhibit all types of COX. The resulting

inhibition of prostaglandin and thromboxane synthesis has the effect of reduced

inflammation, as well as antipyretic, antithrombotic and analgesic effects.

Selectivity for COX-2 is the main feature of celecoxib, rofecoxib, and other members of

this drug class. Because COX-2 is usually specific to inflamed tissue, there is much less

gastric irritation associated with COX-2 inhibitors, with a decreased risk of peptic

ulceration.

A Natural COX inhibitor which is obtained from natural sources is also generally not

selective and inhibits all types of COX. A large number of studies have revealed that

Medicinal Plants have potent anti-inflammatory actions are called Natural COX inhibitor

and such as mushrooms, like Maitake, able to partially inhibit COX-1 and COX-2.14

1. INTRODUCTION 14

1.2.2 Exudative component

The exudative component involves the movement of plasma fluid, containing important

proteins such as fibrin and immunoglobulins (antibodies), into inflamed tissue. This

movement is achieved via the chemically induced dilation and increased permeability of

blood vessels, which results in a net loss of blood plasma. The increased collection of

fluid into the tissue causes it to swell (edema). This extravasated fluid is funneled by

lymphatics to the regional lymph nodes, flushing bacteria along to start the recognition

and attack phase of the adaptive immune system system.14

1.2.3 Vascular changes

Acute inflammation is characterised by marked vascular changes, including vasodilation,

increased permeability and the slowing of blood flow, which are induced by the actions

of various inflammatory mediators. Vasodilation occurs first at the arteriole level,

progressing to the capillary level, and brings about a net increase in the amount of blood

present, causing the redness and heat of inflammation. Increased permeability of the

vessels results in the movement of plasma into the tissues, with resultant stasis due to the

increase in the concentration of the cells within blood - a condition characterized by

enlarged vessels packed with cells. Stasis allows leukocytes to marginate (move) along

the endothelium, a process critical to their recruitment into the tissues. Normal flowing

blood prevents this, as the shearing force along the periphery of the vessels moves cells in

the blood into the middle of the vessel.15

1.2.4 Plasma cascade systems

The complement system, when activated, results in the increased removal of pathogens

via opsonisation and phagocytosis.

The kinin system generates proteins capable of sustaining vasodilation and other physical

inflammatory effects.

The coagulation system or clotting cascade which forms a protective protein mesh over

sites of injury.

The fibrinolysis system, which acts in opposition to the coagulation system, to

counterbalance clotting and generate several other inflammatory mediators.15

1. INTRODUCTION 15

1.2.5 Cellular component

The cellular component involves leukocytes, which normally reside in blood and must

move into the inflamed tissue via extravasation to aid in inflammation. Some act as

phagocytes, ingesting bacteria, viruses, and cellular debris. Others release enzymatic

granules which damage pathogenic invaders. Leukocytes also release inflammatory

mediators which develop and maintain the inflammatory response. Generally speaking,

acute inflammation is mediated by granulocytes, while chronic inflammation is mediated

by mononuclear cells such as monocytes and lymphocytes.15

1.2.6 Leukocyte extravasation

Various leukocytes are critically involved in the initiation and maintenance of

inflammation. These cells must be able to get to the site of injury from their usual

location in the blood, therefore mechanisms exist to recruit and direct leukocytes to the

appropriate place. The process of leukocyte movement from the blood to the tissues

through the blood vessels is known as extravasation, and can be divided up into a number

of steps: 14-15

Leukocyte localisation and recruitment to the endothelium local to the site of

inflammation – involving margination and adhesion to the endothelial cells:

Recruitment of leukocytes is receptor-mediated. The products of inflammation, such as

histamine, promote the immediate expression of P-selectin on endothelial cell surfaces.

This receptor binds weakly to carbohydrate ligands on leukocyte surfaces and causes

them to "roll" along the endothelial surface as bonds are made and broken. Cytokines

from injured cells induce the expression of E-selectin on endothelial cells, which

functions similarly to P-selectin. Cytokines also induce the expression of integrin ligands

on endothelial cells, which further slow leukocytes down. These weakly bound

leukocytes are free to detach if not activated by chemokines produced in injured tissue.

Activation increases the affinity of bound integrin receptors for ligands on the endothelial

cell surface, firmly binding the leukocytes to the endothelium.

Migration across the endothelium, known as transmigration, via the process of

diapedesis: Chemokine gradients stimulate the adhered leukocytes to move between

endothelial cells and pass the basement membrane into the tissues.

1. INTRODUCTION 16

Movement of leukocytes within the tissue via chemotaxis: Leukocytes reaching the

tissue interstitium bind to extracellular matrix proteins via expressed integrins and CD44

to prevent their loss from the site. Chemoattractants cause the leukocytes to move along a

chemotactic gradient towards the source of inflammation.

1.2.7 Morphologic patterns of inflammation

Specific patterns of acute and chronic inflammation are seen during particular situations

that arise in the body, such as when inflammation occurs on an epithelial surface, or

pyogenic bacteria are involved.

Granulomatous inflammation: Characterised by the formation of granulomas, they are

the result of a limited but diverse number of diseases, which include among others

tuberculosis, leprosy, sarcoidosis, and syphilis.

Fibrinous inflammation: Inflammation resulting in a large increase in vascular

permeability allows fibrin to pass through the blood vessels. If an appropriate

procoagulative stimulus is present, such as cancer cells, a fibrinous exudate is deposited.

This is commonly seen in serous cavities, where the conversion of fibrinous exudate into

a scar can occur between serous membranes, limiting their function.

Purulent inflammation: Inflammation resulting in large amount of pus, which consists

of neutrophils, dead cells, and fluid. Infection by pyogenic bacteria such as staphylococci

is characteristic of this kind of inflammation. Large, localised collections of pus enclosed

by surrounding tissues are called abscesses.

Serous inflammation: Characterised by the copious effusion of non-viscous serous fluid,

commonly produced by mesothelial cells of serous membranes, but may be derived from

blood plasma. Skin blisters exemplify this pattern of inflammation.

Ulcerative inflammation: Inflammation occurring near an epithelium can result in the

necrotic loss of tissue from the surface, exposing lower layers. The subsequent

excavation in the epithelium is known as an ulcer.14

1.2.8 Inflammatory disorders

Inflammatory abnormalities are a large group of disorders which underlie a vast variety

of human diseases. The immune system is often involved with inflammatory disorders,

demonstrated in both allergic reactions and some myopathies, with many immune system

disorders resulting in abnormal inflammation. Non-immune diseases with etiological

1. INTRODUCTION 17

origins in inflammatory processes include cancer, atherosclerosis, and ischaemic heart

disease.

A large variety of proteins are involved in inflammation, and any one of them is open to a

genetic mutation which impairs or otherwise dysregulates the normal function and

expression of that protein.14

Examples of disorders associated with inflammation include:

Acne vulgaris

Asthma

Autoimmune diseases

Coeliac disease

Chronic prostatitis

Glomerulonephritis

Hypersensitivities

Inflammatory bowel diseases

Pelvic inflammatory disease

Reperfusion injury

Rheumatoid arthritis

Sarcoidosis

Transplant rejection

Vasculitis

Interstitial cystitis

1.2.9 Resolution of inflammation

The inflammatory response must be actively terminated when no longer needed to

prevent unnecessary "bystander" damage to tissues.14

Failure to do so results in chronic

inflammation, and cellular destruction. Resolution of inflammation occurs by different

mechanisms in different tissues. Mechanisms which serve to terminate inflammation

include: 14, 19

Short half-life of inflammatory mediators in vivo.

Production and release of Transforming growth factor (TGF) beta from macrophages20-22

Production and release of Interleukin 10 (IL-10)23

Production of anti-inflammatory lipoxins24

1. INTRODUCTION 18

Downregulation of pro-inflammatory molecules, such as leukotrienes

Upregulation of anti-inflammatory molecules such as the Interleukin 1 receptor

antagonist or the soluble tumor necrosis factor receptor (TNFR)

Apoptosis of pro-inflammatory cells25

Desensitization of receptors

Increased survival of cells in regions of inflammation due to their interaction with the

extracellular matrix (ECM)26-27

Downregulation of receptor activity by high concentrations of ligands

Cleavage of chemokines by matrix metalloproteinases (MMPs) might lead to production

of anti-inflammatory factors.26

1.2.10 Exercise as a treatment for inflammation

Regular physical activity is reported to decrease markers of inflammation28-30

although

the correlation is imperfect and seems to reveal differing results contingent upon training

intensity. For instance, while baseline measurements of circulating inflammatory markers

do not seem to differ greatly between healthy trained and untrained adults, long-term

chronic training may help reduce chronic low-grade inflammation.31-33

On the other hand,

levels of inflammatory markers (IL-6) remained elevated longer into the recovery period

following an acute bout of exercise in patients with inflammatory diseases, relative to the

recovery of healthy controls. It may well be that low-intensity training can reduce resting

pro-inflammatory markers (CRP, IL-6), while moderate-intensity training has milder and

less-established anti-inflammatory benefits.34-35

There is a strong relationship between

exhaustive exercise and chronic low-grade inflammation. Marathon running may enhance

IL-6 levels as much as 100 times over normal and increases total leuckocyte count and

neturophil mobilization. As such, individuals pursuing exercise as a means to treat the

other factors behind chronic inflammation may wish to balance their exercise protocol

with bouts of low-intensity training, while striving to avoid chronic over-exertion.36., 37

1.2.11 Medicinal Plants as Anti-Inflammatory Agents

Ananas comosus ( L.) Merr. (Bromeliaceae)

Ananas comosus (L.) Merril (Pineapple) has been used as a medicinal plant in several

native cultures and its major active principle, Bromelain, has been known chemically

since 1876. Bromelain is a general name for a family of sulphydryl proteolytic

1. INTRODUCTION 19

compounds obtained from Ananas comosus L. The primary component of bromelain is a

sulphydryl proteolytic fraction. It also contains peroxidase, acid phosphatase, several

protease inhibitors and originally bound calcium. Eight basic proteolytically active

components have been detected in the stem. Bromelain seems to have both direct as well

as indirect actions involving other enzyme systems exerting its anti-inflammatory effect.

It inhibits the inflammatory pain in rats in a dose dependent manner. It reduces pain and

inflammation associated with surgery, arthritis, trauma or sports injury. Bromelain was

the most potent of nine anti-inflammatory substances tested on experimental rats.

Bromelain interferes with the arachidonic acid cascade there by preventing the formation

of pro-inflammatory eicosanoids. Non-steroidal anti-inflammatory drugs inhibit COX,

which is required for the synthesis of two prostaglandins, resulting in a decrease in both

pro and anti-inflammatory prostaglandins. Bromelain has been shown to inhibit

prostaglandins even though its action is significantly weaker. Bromelain has been shown

to reduce edema, accelerate healing and lowers pain and inflammation after surgery in

clinical trials.38

Boswellia serrata Roxb. (Burseraceae)

Boswellia serrata Roxb has been used traditionally in Indian Ayurvedic medicine and is

well known for its anti-inflammatory activity. The resinous gum of the bark is known as

guggulu in Ayurveda and is also used in modern phytomedicine. It has been reported to

be a powerful anti-inflammatory agent without the ulceration or irritation as observed in

non-steroidal anti-inflammatory drugs. Bosewellia has been shown to possess sedative,

analgesic, anti-inflammatory and anticancer effects. The resin obtained from the plant is

recommended for rheumatoid arthritis, osteoarthritis, fibromyositis and spondylitis.

Patients treated with Bosewellia reported decreases in knee pain, joint swelling and

increases in knee flexion and walking distance. Four pentacyclic triterpene acids

including the bioactive compound β-boswellic acid which interferes with leukotriene

biosynthesis have been isolated from B. serrata. It is a specific and dose dependent

inhibitor of 5- lipoxygenase, 5-eicosatetraenoic acid and leukotriene B4. These chemical

mediators of inflammation are implicated in the pathogenesis of many diseases including

asthma, arthritis, colitis and cancer. Bosewellia inhibits human leukocyte elastase (HLE)

under in vitro conditions. HLE inhibitor medications have been developed for the

1. INTRODUCTION 20

treatment of asthma, emphysema and cystic fibrosis. Bosewellic acids were found to be

more potent inhibitors of human topoisomerases-I and II-α than chemotherapeutic agents

that work largely by inhibition of these enzymes. The mechanism of action of beta

boswellic acid has been recently reported. B. serrata extract can decrease the

glycosaminoglycan degradation which keeps the cartilages in better condition thus

preventing the progression of osteoarthritis.39

Callophyllum inophyllum L. and Mesua ferrea L. (Clusiaceae)

Callophyllum inophyllum L. and Mesua ferrea L. has been commonly used for the

treatment of rheumatism, skin diseases, dysentery and bleeding piles. The whole plant is

medicinal and contains compounds such as xanthones, triterpenes, coumarins and

glucosides. The xanthones of Callophyllum and Mesua have been found to produce

significant anti-inflammatory activity in normal as well as adrenalectomised rats by both

intra-peritoneal and oral routes. Usually the anti-inflammatory agents in clinical use

exhibit analgesic and antipyretic properties along with ulcerogenicity and impairment of

blood clotting as side effects. But the xanthones of C. inophyllum and M. ferrea did not

possess any such properties and thus points to the possibility of developing anti-

inflammatory drugs of future use.40

Calotropis gigantea (L.) R. Br. (Asclepiadaceae)

Calotropis gigantea (L.) R. Br. is an important medicinal plant where all parts of the

plant including the milky secretion have been claimed to possess varied medicinal uses. It

has been claimed to be useful in treating skin diseases and healing of wounds and ulcers.

The methanolic extract of Calotropis gigantea leaves revealed the anti-inflammatory

activity in experimental rats using paw edema test. Anti-inflammatory effects of aqueous

extract of leaves and latex of C. procera were reported earlier.41

Calotropis procera (Ak.) R.Br. (Asclepiadaceae)

Calotropis procera (Ait) R Br. is a well known medicinal plant in the traditional

medicine system of India. It is used in the treatment of skin diseases, rheumatism and

aches. It has been reported to possess antiinflammatory, analgesic and weak antipyretic

activities. The latex was reported to be as potent as standard anti-inflammatory drug

phenylbutazone in inhibiting inflammatory response induced by different inflammatory

agents in acute and chronic models. The anti-inflammatory activity of the latex of C.

1. INTRODUCTION 21

procera and its methanolic extract against various inflammatory mediators as well as on

leucocyte flux induced by carrageenan in rat paw edema model have been reported.41

Camellia sinensis (L.) Kuntze (Theaceae)

Camellia sinensis (L.) Kuntze is one of the most commonly consumed beverages in the

world. The established pharmacological activity of the green tea extracts are attributed to

its high content of polyphenols/catechins, mainly epigallocatechin-3-gallate (EGCG). The

potential effect of green tea in arthritis on collagen type-II-induced arthritis in mice has

been reported. The anti-inflammatory effect of green tea polyphenols was reflected in a

marked inhibition of the inflammatory mediators such as COX 2, interferon–γ and TNF-α

in arthritic joints. Histopathological studies revealed a reduction in biochemical markers

correlated with the marked reduction in inflammation in synovium. Studies have shown

that most of the effects of green tea extracts are mimicked by its constituent polyphenol,

EGCG. Further studies have shown that EGCG inhibited the transcription factor, nuclear

factor-kappa-B (NF-κ B) inconjunction with pro-inflammatory cytokines IL-1β-inducible

nitric oxide synthase (Inos) and COX 2, resulting in reduction of nitric oxide and

prostaglandin E2 (PGE2) in vitro.41

Cannabis sativa L. (Cannabinaceae)

Cannabis sativa L. has been used in various preparations for their medicinal effects

including anti-pyretic, anti-rheumatic, anti-allergic and analgesic purposes. It is possible

that the anti-inflammatory and anti-asthmatic properties of this herb are mediated through

effects on arachidonate metabolism. The constituents of Cannabis are known to stimulate

and inhibit prostaglandin releases by influencing enzymes of the arachidonate pathway.41

Centella asiatica (L.) Urban

It belongs to the family Apiaceae and is commonly found in parts of Asia and the Middle

East. Centella has been used in traditional medicine in Asia for 100 years. In Ayurveda,

Centella is effectively used in the treatment of inflammation, anaemia, asthma, blood

disorders, bronchitis, fever, urinary discharge and splenomegaly. The water extract of the

plant was used to study the anti-inflammatory and analgesic activity in adult male rats.

The extract elicited dose dependent anti-inflammatory activity at 2 mg/kg concentration.

This study revealed that the extract is similar to mefenamic acid and interestingly 10

mg/kg extract showed a significantly higher effect when compared to mefenamic acid.

1. INTRODUCTION 22

These compoundsmay be present in the extract which contributes to the anti-

inflammatory and analgesic property in the study. These findings justify the traditional

use of Centella in the treatment of inflammatory conditions.41

Curcuma longa L. (Zingiberaceae)

Curcuma longa L. is a perennial herb distributed throughout tropical and subtropical

regions of the world. It is widely cultivated in Asiatic countries, mainly in India and

China. As turmeric powder it has been in continuous use for its flavouring, as a spice in

both vegetarian and non-vegetarian food preparations and has digestive properties. There

is a great number of papers in the literature relating the activity of compounds extracted

from C. longa L. being potent inhibitors of inflammation. The activity of curcumin and

other semi synthetic analogues in experimental rats were demonstrated. Studies on anti

inflammatory activities included in vitro, animal and human models. The laboratory

studies have identified a number of different molecules involved in inflammation that are

inhibited by curcumin including phospholipase, lipoxygenase, cyclooxygenase-2,

leukotriens, thromboxane, prostaglandins, nitric oxide, collagenase, elastase,

hyaluronidase, monocyte chemoattractant protein-1 (MCP-1), interferon–inducible

protein, tumour necrosis factor (TNF) and interleukin-12 (IL-12). The anti-inflammatory

activity demonstrated in the experiment may be due to inhibition of a number of different

molecules that play a role in inflammation. In animal studies, oral administration of

curcumin to rats decreased the levels of inflammatory glycoprotein with a reduction in

paw inflammation. Curcumin was also found to be inhibiting the carrageenan induced

paw edema in mice and rats with an ED 50 dose 48 and 100.2 mg/kg respectively.41

Euphorbia heterophylla L. (Euphorbiaceae)

Euphorbia heterophylla is a local medicinal plant commonly known as ‘spurge weed’. It

is used in ethnomedicine for the treatment of constipation, bronchitis and asthma [94]. It

grows in semi humid places especially in cassava, cow pea and soyabean plantations.

Phytochemical studies have revealed the presence of saponins, diterpenes and

phorbolesters in the extracts. The anti-inflammatory activity of the aqueous and

methanolic extract of Euphorbia heterophylla were evaluated by carrageenin induced rat

paw edema test. The aqueous extract of Euphorbia showed significant anti-inflammatory

activity (P<0.001) comparable to the reference drug. But the methanolic extract did not

1. INTRODUCTION 23

show any appreciable anti-inflammatory activity. These studies were in agreement with

the earlier investigations suggesting the presence of a flavanoid, quercetin, which is a

known anti-inflammatory agent. The significant level of anti inflammatory activity of the

aqueous extract could be attributed to high amount of flavanoids present in the extract.

This study justifies the traditional use of Euphorbia in the treatment of inflammatory

disease conditions such as asthma. 41

Gastrodia elata Blume (Orchidaceae)

Gastrodia elata Blume is a very important traditional herbal medicine used to treat head

ache, migraine, dizziness, epilepsy, rheumatism, neuralgia, paralysis and other disorders.

The anti-inflammatory and analgesic activities of these phenolic extracts were studied

using animal models. They suggested that these phenolic compounds inhibited COX

activity and silica induced reactive oxygen species (ROS) generation in a dose-dependent

manner. The phenolic compounds of Gastrodia elata are anti-inflammatory, which could

be related to inhibition of COX activity and to anti-oxidant activity. Consideration of the

structure-activity relationship of these compounds of G. elata on the anti-inflammatory

action revealed that both C-4 hydroxy and C-3 methoxy radicals of benzyl aldehyde play

an important role in anti-inflammatory activities. 41

Harpagophytum procumbens (Burch.) DC (Pedaliaceae)

Harpagophytum procumbens (Burch.) DC is commonly known as Devil’s claw and is a

native of South Africa. The root tubers of the plant are used in herbal preparations. Leung

and Foster reported three iridoid glycosides viz. harpagoside, harpagide and procumbide

and are responsible for the anti-inflammatory and analgesic actions. These glycosides

effectively reduced Osteoarthritis (OA) pain and was comparable with that of the

analgesic/ cartilage protective drug, Diacerhein. H. procumbens at the rate of 600-120

mg/day was helpful in reducing low back pain. The anti-inflammatory and analgesic

effect of the aqueous extract of H. procumbens has been reported recently. 41

Kalanchoe crenata Andr. (Crassulaceae)

Klanchoe crenata Andr. is commonly known as “never die” or “dog’s liver”. It has been

traditionally used for the treatment of ear ache, small pox, head ache, inflammation, pain,

asthma, palpitations, convulsion and general debility. The anti-inflammatory property of

the leaf extract of K. crenata was scientifically validated. They reported the presence of

1. INTRODUCTION 24

sterols, flavanoids and saponins in the different extracts which were responsible for the

acute and chronic anti-inflammatory activity against various phlogistic agents. They act

by inhibition of COX and therefore inhibit the production of gastric prostaglandins which

in turn leads to a reduction in the gastric mucus and an increase in mucosal permeability.

This can be attributed to the inhibition of COX. Hence, it was concluded from this study

that the flavanoids in the n-butanol fraction was responsible for its pharmacological

activities. 41

Mangifera indica L. (Anacardiaceae)

Mangifera indica L. aqueous extract, known as Vimang in Cuba, is used to improve the

quality of life in patients suffering from elevated stress. Mangifera indica bark aqueous

extract. Analgesia was determined using acetic acid induced abdominal constriction and

formalin induced licking. Antiinflammatory effects were studied using carrageenin and

formalin inducededema. They reported polyphenols in the extract which might be

responsible for the effect. Edema formation was significantly inhibited both in

carrageenin and formalin models. 41

Plumeria accuminata W.T. Aiton (Apocyanaceae)

Plumeria acuminata W.T. Aiton belongs to the family Apocynaceae and is widely

distributed in Southern parts of India. In traditional medicine system different parts of the

plant have been used in a variety of diseases. The milky juice is employed for the

treatment of inflammation and rheumatism. The leaves are reported to have anti-

inflammatory and rubefacient in rheumatism and have strong purgative effect. The

methanol extract of Plumeria acuminata exhibited significant anti-inflammatory activity

on the tested experimental models in both acute and chronic inflammation models. The

Methanolic extract produced significant (P<0.001) anti-inflammatory activity and the

results were comparable to that of indomethacin as a standard anti-inflammatory drug.

Their studies indicated that the extract acted in later phases probably involving

arachidonic acid metabolites which produce an edema dependent on neutrophil

mobilization. 41

Ricinus communis L. (Euphorbiaceae)

Ricinus communis Linn. is a small tree distributed throughout the tropics and warm

temperate regions of the world. In Indian traditional system of medicine different parts of

1. INTRODUCTION 25

this plant has been used to cure inflammation and liver disorders. The anti-inflammatory

activity of the methanolic extract of Ricinus communis Linn. root was reported by the

methanolic extract at a dose of 250 mg/kg p.o exhibited significant (p<0.001) anti-

inflammatory activity in carrageenin induced rat paw edema model and a higher dose of

500 mg/kg p.o also\ exhibited significant (p<0.001) activity in cotton pellet granuloma

model in Wistar albino rats. Flavanoids have been reported to have anti-inflammatory

and antiarthritic activity. The anti-inflammatory activity of Ricinus can be attributed to

the presence of phytochemicals such as flavanoids, alkaloids and tannins in the plant

extract. 41

Salix alba L. (Salicaceae)

Salix alba L. is commonly known as the Willow tree and its bark contains heavy

concentrations of salicin, a glycoside, which is the precursor of aspirin. Salicin is

responsible for the anti-inflammatory and analgesic actions. The consumption of herbal

combination containing 100 mg willow bark for two months improved functioning via

pain relief in OA. A trial study revealed that 1360 mg of willow bark extract per day

(delivering 240 mg of salicin) for two weeks to be effective in treating pain associated

with knee and hip. A four week trial found that willow extract containing 240 mg of

salicin was effective in reducing exacerbations of low back pain. 42

Sida cordifolia L. (Malvaceae)

Sida cordifolia Linn is an extensively used herbal ingredient in the Ayurvedic system of

medicine in the Indian subcontinent. The antiinflammatory and analgesic activities of the

water extract of the plant in animal models were reported. Phytochemical analyses from

time to time have revealed the presence of ephedrine, vasicinol, vascicinone and N-

methyl tryptophan. Chloroform, methanol, ethyl acetate and butanol extracts also showed

significant activity in experimental models. In addition another chemical constituent (5' –

Hydroxymethyl - 1'-(1,2,3,9-tetrahydro-pyrrolo[2,1-b] quinazolin -1- yl)-heptan-1-one)

was reported141 from the aerial parts of Sida cordifolia. The bioactivity thus reported

was due to the inhibitory effect of the compound by the inhibition of COX enzyme

leading to the inhibition of prostaglandin synthesis. 41

1. INTRODUCTION 26

Silybum marianum (L.) Gaertn. (Asteraceae)

Silybum marianum (L.) Gaertn. is an important medicinal plant commonly known as

‘Milk thistle’ or ‘St. Mary’s Thistle’. The anti-inflammatory activity of this plant has

been reported earlier. The plant extract was reported to contain an important bioactive

principle, sylimarin, which belongs to the flavanolignan group and possess anticancer,

antiinflammatory, antioxidant and immunomodulatory effects. 43

Spilanthes acmella Murr. (Asteraceae)

Spilanthes acmella Murr. is an indigenous herb growing as an annual throughout the

tropics. The whole plant is claimed to possess medicinal properties. The flowers are

chewed to relieve tooth ache and the crushed plant is used in rheumatism. The presence

of flavanoids in the aqueous extract which is responsible for the significant anti-

inflammatory and analgesic property of the plant. The extract produced dose dependent

and significant inhibition of prostaglandins which are involved in the late phase of acute

inflammation and pain perception. 44

Tripterygium wilfordii Hook F (Celastraceae)

Tripterygium wilfordii Hook F is a perennial vine like plant that grows in China and

Thaiwan. The root of the plant is medicinal and is used for the treatment of inflammatory

diseases like rheumatoid arthritis, asthma, nephritis etc for centuries ago. The ethanolic

and ethyl acetate extract of the plant is used in the treatment of rheumatoid arthritis. The

anti-inflammatory effect of T. wilfordii was believed to be due to the presence of

triptolide, the active ingredient. 45

Uncaria tomentosa (Willd.) DC. and U. guianensis J.F. Gmel (Rubiaceae)

Uncaria tomentosa (Willd.) DC. and U. guianensis DC commonly known as Cat’s claw

is a Peruvian vine with medicinal properties that are well documented in alternative

medicine literature. The anti-inflammatory activity of Cat’s claw extract was reported

earlier.In Peruvian medicinal system, the extract of both species has been used

interchangeably to treat inflammatory and non-inflammatory conditions. The chemical

composition of U. tomentosa and U. guianensis vary and accordingly the anti-

inflammatory effects are independent of one another. The anti-inflammatory activity of

U. tomentosa is mainly due to the active constituent, pentacyclic oxindole alkaloid.46

1. INTRODUCTION 27

Zingiber officinale Roscoe (Zingiberaceae)

Zingiber officinale Rosc. is one of the most common constituents of diets world wide and

is reported to possess antioxidant, anti-inflammatory, antiseptic anti-inflammatory,

analgesic and carminative properties. In folk medicine it has been used against pain,

inflammation, arthritis, urinary infections and gastrointestinal disorders. Ayurveda

supports the use of ginger to treat inflammatory and rheumatic disorders. Ginger oil

contains a mixture of constituents like monoterpenes and sesquiterpenes which were

reported to have anti-inflammatory and analgesic activities. The anti-inflammatory

activity of the ginger essential oil was determined by pleuricy test using carrageenan (200

μg /cavity) in experimental mice. Ginger essential oil and indomethacin in 200 and 500

mg/kg was significant in proving anti-inflammatory activity. The experimental data

suggested that ginger essential oil does not have influence on cells’ recruitment different

to that observed for other essential oils. Gingerol has been reported to have anti-

inflammatory actions, which include suppression of both COX metabolites of arachidonic

acid . The anti-inflammatory activity shown by ginger essential oil could be owing to the

inhibition of prostaglandin release and hence ginger may act in a way similar to other

nonsteroidal anti-inflammatory drugs which interfere with prostaglandin biosynthesis.47

1.3 TOPICAL DRUG DELIVERY SYSTEM

Topical preparations are used for the localized effects at the site of their application by

virtue of drug penetration into the underlying layers of skin or mucous membranes. The

main advantage of topical delivery system is to bypass first pass metabolism. Avoidance

of the risks and inconveniences of intravenous therapy and of the varied conditions of

absorption, like pH changes, presence of enzymes, gastric emptying time are other

advantage of topical preparations. Semi-solid formulation in all their diversity dominate

the system for topical delivery, but foams, spray, medicated powders, solution, and even

medicated adhesive systems are in use. The topical drug delivery system is generally used

where the others system of drug administration fails or it is mainly used in pain

management, contraception, and urinary incontinence48.

Topical delivery includes two basic types of product:

External topicals that are spread, sprayed, or otherwise dispersed on to cutaneous tissues

to cover the affected area.

1. INTRODUCTION 28

Internal topicals that are applied to the mucous membrane orally, vaginally or

on anorectal tissues for local activity49

.

For the most part topical preparations are used for the localized effects at the site of their

application by virtue of drug penetration into the underlying layers of skin or mucous

membranes. Although some unintended drug absorption may occur, it is sub therapeutics

quantities and generally of minor concern50

.

1.3.1 Advantages of Topical Drug Delivery Systems: 51-52

Avoidance of first pass metabolism.

Convenient and easy to apply.

Avoidance of the risks and inconveniences of intravenous therapy and of the varied

conditions of absorption, like pH changes, presence of enzymes, gastric emptying time

etc.

Achievement of efficacy with lower total daily dosage of drug by continuous drug input.

Avoids fluctuation in drug levels, inter- and intrapatient variations.

Ability to easily terminate the medications, when needed.

A relatively large area of application in comparison with buccal or nasal cavity

Ability to deliver drug more selectively to a specific site.

Avoidance of gastro-intestinal incompatibility.

Providing utilization of drugs with short biological half-life, narrow therapeutic window.

Improving physiological and pharmacological response.

Improve patient compliance.

Provide suitability for self-medication.

Disadvantages of Topical Drug Delivery Systems: 53-54

Skin irritation of contact dermatitis may occur due to the drug and/or excipients.

Poor permeability of some drugs through the skin.

Possibility of allergenic reactions.

Can be used only for drugs which require very small plasma concentration for action

Enzyme in epidermis may denature the drugs

Drugs of larger particle size not easy to absorb through the skin

1.3.2 Classification of Topical Drug Delivery Systems: 54

Classification of Topical Drug Delivery Systems based on physical state

1. INTRODUCTION 29

(A) Solid:

Powder

Aerosol

Plaster

(B)Liquid:

Lotion

Liniment

Solution

Emulsion

Suspension

Aerosol

1.3.3 Skin

Delivery of drugs to the skin is an effective and targeted therapy for local dermatological

disorders. This route of drug delivery has gained popularity because it avoids first-pass

effects, gastro-intestinal (GI) irritation, and metabolic degradation associated with oral

administration. Topical formulations provide a suitable delivery system for drugs because

they are less greasy and can be easily removed from the skin. Nowadays the extensive

research has been considered that topical route is possible site for the systemic, localized

delivery of drug.55

For the topical drug delivery, the main barrier is skin. To understand the concept of

topical drug delivery system, it is important to review the structural and biochemical

features of human skin and those characteristics which contribute to the barrier function

and the rate of drug access into the body via skin.

Anatomy and physiology of skin

Human skin is, on average, 0.5 mm to 2 mm and composed of four main layers: the

stratum corneum, viable epidermis, dermis and subcutaneous tissue (Fig.1.2).The thick

(10-20mm) surface layer, the stratum corneum is highly hydrophobic and contains 10-15

layers of interdigitated corneocytes, which are constantly shed and renewed. Its

organization can be the “brick and mortar” model, in which extracellular lipid accounts

(c) Semi-solid:

Ointment

Cream

Paste

Gel

Jelly

Suppository

1. INTRODUCTION 30

for 10% of the dry weight of this layer, and the 90% is intracellular protein (mainly

keratin).56,57

The stratum corneum lacks phospholipids, but is enriched in ceramides and neutral lipids

(cholesterol, fatty acids, cholesteryl esters) that are arranged in a bilayer format and form

so called ‘lipid channels’. Barrier lipids are tightly controlled and any impairment to the

skin results in active synthetic processes to restore them. The skin’s barrier function

appears to depend on the specific ratio of various lipids.

Because of its highly organized structure the stratum corneum is permeability barrier to

external materials, and is regarded as the rate- limiting factor in the penetration of

therapeutic agents through the skin. The ability of various agents to interact with the

intercellular lipid therefore dictates the degree to which absorption is enhanced.

Figure 1.2: Structure of skin

Epidermis:

The viable epidermis consists of multiple layers of keratinoctes at various stages of

differentiation. The basal layer contains actively dividing cells, which migrate upwards to

successively form the spinous, granular and clear layers. As part of this process, the cells

gradually lose their nuclei and undergo changes in composition. The role of the viable

epidermis in skin barrier function is mainly related to the intercellular lipid channels and

1. INTRODUCTION 31

to several partitioning phenomena. Depending on their solubility, drugs can partition

from layer to layer after diffusing through the stratum corneum. Several other cells (e.g.

melanocytes, langerhans cells, dendritic T cells, and epidermotropic lymphoctes) are also

scattered throughout the viable epidermis, which also contains a variety of active

catabolic enzymes (e.g. esterases, phosphatases, proteases nucleotidases and lipases.

Dermis and hypodermis

The dermis is largely a layer that is rich in blood vessels, lymphatic vessels and nerve

endings. An extensive network of dermal capillaries connects to the systemic circulation,

with considerable horizontal branching from the arterioles and venules in the papillary

dermis to form plexuses and to supply capillaries to hair follicles and glands. Dermal

lymphatic vessels help drain excess extra cellular fluid and clear antigenic materials.

The elasticity of the dermis is attributed to a network of protein fibers, including collagen

(type 1 and 3) and elastin, which are embedded in an amorphous glycosaminoglycan

ground substance. The dermis also contains scattered fibroblasts, macrophages, mast cells

and leukocytes. Hair follicles, sebaceous glands and sweat glands are found in the dermis

and subcutis, and might serve as additional specific, albeit fairly limited pathways for

drug absorption.58

1.3.4 Mechanism of topical delivery

When a drug system is applied topically, the drug diffuses out of its vehicle onto the

surface tissues of the skin. There are three potential portals of entry: through the follicular

region, through the sweat ducts, or through the unbroken stratum corneum between these

appendages. There is little convincing evidence that eccrine sweat glands play any

significant role in cutaneous permeability. Material may enter the ducts, and even the

glands, but there appears to be no penetration from these areas to the dermis.

For substances absorbed by the transepidermal route, penetration is fairly rapid, although

slower than intestinal tract absorption, and is almost always accompanied by some degree

of pilosebeceous penetration as well. For substances that are absorbed through both

pathways, the transepidermal route is the principal portal of entry because of the total,

relatively small, absorbing surface offered by the pilosebeceous units. The epidermis

presents a surface area 100 to 1000 times greater than the other routes of absorption. The

appendages, sweat glands, and hair follicles are scattered throughout the skin in varying

1. INTRODUCTION 32

numbers, but are comparatively sparse; their total cross-sectional area is probably

between 0.1 and 1.0% of the skin area.

Once a substance passes through the stratum corneum, there is apparently no significant

further hindrance to penetration of the remaining epidermal layers and corneum; there is

a ready entry into the circulation via the capillaries. The concentration gradient

essentially ends in the dermal layer at the beginning of the circulation. The systemic

circulation acts as a reservoir or “sinks” for the drug. Once in the general circulation, the

drug is diluted and distributed rapidly with little systemic buildup.(Fig.1.2 )

Diffusion through the horny layer is a passive process. There is little evidence to support

specialized active transport systems for cells of the stratum corneum. The passive process

is affected only by the substance being absorbed, by the medium in which the substance

is dispersed, and by ambient conditions. On the other hand, percutaneous absorption is a

more complicated process, of which epidermal diffusion is the first phase, and clearance

from the dermis the second. The latter depends on effective blood flow, interstitial fluid

movement, lymphatics, and perhaps other factors that combine with dermal

constituents.59

1.3.5 Physical chemistry of percutaneous absorption

There has been little evidence to suggest that there are any active processes involved in

skin permeation therefore the underlining transport process is controlled by simple

passive diffusion. Fick’s laws of diffusion can be used to analyze permeation data and

can be used predicatively. Fick’s first law is used to describe steady state diffusion and

can be define as:-

J = DKΔC / h …….. (1)

Where J is the flux per unit area, D is the diffusion coefficient in the skin, K is the skin

vehicle partition coefficient, ΔC is the concentration difference across the skin, and h is

the diffusional path length.

Under normal circumstances the applied concentration (CAPP) is very much larger than

the concentration under the skin and equation 1 is often simplified to:

J = Kp* CAPP ………. (2)

1. INTRODUCTION 33

Where Kp is a permeability coefficient (= KD/h) and is a heterogeneous rate constant

having the units cm/h. As will become apparent, it is often difficult to separate K and D

and their calculated magnitude will depend on ‘h’ that cannot be accurately estimated as

it is the tortuosity of the intracellular channels, which is imprecise58

.

1.3.6 Drug absorption

Percutaneous absorption of drugs from topical formulations involves the release of the

drug from the formulation and permeation through skin to reach the target tissue. The

release of the drug from topical preparation depends on the physicochemical properties of

the vehicle and the drug employed. In order to enhance drug release and skin permeation,

methods such as the selection of a suitable vehicle, co-administration of a chemical

enhancer, and iontophoresis have been studied 55

.

There are many traditional valuable dermatological systems available which apply

topically, for example- semisolid preparation (e.g. cream, ointment), and liquid

preparations, etc. which have a considerable problem in the delivery of medicament

through the skin, is impermeability, low bioavailability, and only few percentage of the

active material reaches to the target site.

This can be improved by developing novel dermatological formulation which is much

more efficient and effective than traditional topical system. Nowadays different carrier

systems has been extensively investigated for the topical delivery of drugs, such as

liposomes, niosomes, transfersomes, ethosomes, solid lipid nanoparticles and

microemulsion etc.

1.3.7 Physicochemical criteria for topical formulation

Stability of the active ingredients

Stability of the adjuvant

Rheological properties- consistency, extrudability

Loss of water and other volatile components

Phase changes- homogeneity, phase separation

Particle size and particles size distribution

Apparent pH

Particulate contamination.59

1.3.8 Ideal properties of topical formulation

1. INTRODUCTION 34

Achieves a concentration in the target tissue that is sufficient to produce desired

pharmacological response

Preferably non toxic

Leaves the skin in an inactive form (as a metabolite)60

1.3.9 Vesicular approaches for topical delivery system59

Various vesicular systems are used to increase drug transport across the skin. They are as

follows:

1.3.10 Formulation approaches

Penetration enhancement with special formulation approaches is mainly based on the

usage of colloidal carriers. Submicron sized particles are intended to transport entrapped

active molecules into the skin. Such carriers include liposomes, nanoemulsions, and

solid-lipid nanoparticles (Fig.1.3). Most reports cite a localizing effect whereby the

carriers accumulate in stratum corneum or other upper skin layers. Generally, these

colloidal carriers are not expected to penetrate into viable skin. However, the

effectiveness of these carriers is still under debate. 60-61

Figure 1.3: Vesicular approaches for topical delivery system

Liposomes

Liposomes are made up of amphiphlic molecules (phospholipids and mixture of lipids

containing phospholipids) capable of self-organization properties. These molecules are

able to form a lipidic bilayer and this bilayer encapsulates a small internal aqueous

volume. Hydrophilic molecules can be encapsulated in the internal aqueous volume

where as amphiphlic molecules can be incorporated in the bilayer. Liposomes are formed

1. INTRODUCTION 35

when thin lipid films or lipid cake are hydrated and stacks of liquid crystalline bilayers

become fluid and swell. The hydrated lipid sheets detach during agitation and self-close

to form large multilamellar vesicles (LMV) which prevents interaction of water with the

hydrocarbon core of the bilayer at the edges, once these particles have formed, reducing

the size of the particle requires energy input in the form of sonic energy (Sonication) or

mechanical energy (extrusion). Properties of lipid formulations can vary depending on

the composition (cationic, anionic, neutral lipid species).

Niosomes

Niosomes are non-ionic surfactant based multilamellar or unilamellar vesicles in which

an aqueous solution of solute is entirely enclosed by a membrane resulted from the

organization of surfactant macromolecules as bilayer.

Pharmacosomes

Pharmacosomes are colloidal dispersions of drugs covalently bound to lipids and may

exist as ultra fine vesicular, micellar or hexagonal aggregate depending on the chemical

structure of the drug-lipid complex. The development of vesicular pharmacosomes is

based on surface and bulk interactions of lipids with water. Any drug possessing an

active hydrogen atom (-COOH,-OH,-NH2, etc) can be esterified to the lipid with or

without spacer chain, the limitation of liposomes and niosomes can be overcome by

pharmacosome approach.

Ethosomes

Ethosomal system is a vesicular system composed mainly of phospholipids, alcohol

(ethanol and isopropyl alcohol) in relatively high concentration, sometime glycols

(polyols) and water. Ethosomes contain high concentration of ethanol that is responsible

for their better skin permeation ability. Ethosomal system is vesicular in nature,

depending on the ratio of components and the chemical structure of the phospholipids can

be comprised of very small entities (nm).

Hydrogels in topical delivery

Hydrogels are three dimensional, water-swollen structure composed of mainly

hydrophilic homopolymers or copolymers. They are rendered insoluble due to cross-

linking by chemical bonds, or other cohesion forces such as ionic interaction, hydrogen

bonding, or hydrophobic interaction. Hydrogels are elastic solids because they exist in a

1. INTRODUCTION 36

reference configuration to which the system returns even after being deformed for a very

long time.

Transfersome

A transfersome is an artificial vesicle designed to be like a cell vesicle, and used to

deliver drugs or genetic material into a cell. A basic transfersome is composed of one

natural amphipath (such as phosphatidylcholine) that tends to self-aggregate into vesicles.

The latter are then supplemented by at least one bilayer softener (e.g. a biocompatible

surfactant). The vesicle-like Transfersome thus normally possesses an aqueous core

surrounded by a complex, very fluid and adaptable lipid bilayer. In its basic organization

is broadly similar to a simple lipid vesicle (a so-called liposome), a Transfersome differs

from the latter by its more flexible and permeable, "softened" bilayer membrane.

Out of this mentioned delivery system, the present work emphasize on potentiality of

ethosomes as smart drug delivery system for treatment of inflammation. Smart Delivery

Systems that are now a day’s famous for topical application are summarized in

(Table1.1).

1.3.11 Ethosomes

In the early 1980s, Mezei and his group described liposomes as the first topical lipid

vesicular system for enhanced drug delivery to the skin. Since then, many works have

shown that lipid vesicular systems are able to increase the accumulation of various

molecules in the SC or other upper skin layers. Drug delivery from such vesicles results

in the formation of a drug reservoir in the horny layer of the skin and is generally

characterized by a lack of penetration into the deeper layers of the skin. This behavior is

useful both for local treatment of skin disorders and for cosmetic formulations. Specific

drug accumulation at the site of action and decreased systemic drug absorption can

impart increased efficiency as well as decreased side effects for a compound applied

topically. Early works by Mezei and coworkers reported that application of triamcinolone

acetonide encapsulated within liposomes to depilated rabbit skin in vivo resulted in a

fourfold increase in the amount of drug accumulated in the epidermis, as compared to

application of the same drug concentration in an ointment base. More recently, Touitou’s

group studied the delivery of dyphylline incorporated in unilamellar liposomes from

polyethylene glycol (PEG),carbopol gel, a PEG enhancer base and water. Conversely,

1. INTRODUCTION 37

when caffeine delivered from small unilamellar liposomes, was found mostly localized

into the skin. By using quantitative autoradiography, it was also found that the

concentration of the drug was greatest in the epidermis, lowest in the dermis, and

relatively high in the appendages. As discussed above, conventional liposomal systems

were demonstrated to be effective at delivering active agents to the upper layers of the

skin. More recently, novel lipid vesicular systems that are capable of penetrating to the

deep layers of the skin and delivering the active agents transdermally have been invented

by Prof. Elka Touitou from the Faculty of Medicine, Hebrew University in Jerusalem,

Israel in1996 as additional novel lipid carriers composed of ethanol, phospholipid, and

water termed as Ethosomes.63

Table 1.1: Smart delivery system

Ethosomes are soft, malleable, tiny bubble like lipid vesicles composed mainly of

phospholipids, ethanol (relatively high concentration) and water. These “soft vesicles”

S.No Systems Example Delivers

1. Emulsions Microemulsions, liquid crystals,

multipleemulsion, nanoemulsions,

pickering emulsions

Carotenoids, vitaminA

palmitate, free radical

scavengers, nitrocellulose

and antimicrobials.

2. Particulate

delivery

systems

Microparticulates,porous polymeric

systems, nanoparticulates,

cyclodextrin, melanosponge

Vegetable oil, tocopherols,

retinal, tocopherols,

genetically engineered

melanin.

3. Vesicle

delivery

systems

Ethosomes, liposomes, photosomes,

niosomes siliconevesicles,matrices,

multi-walled-delivery systems,

phytosome, marinosomes

ultrasomes, asymmetric-oxygen

carrier system (AOCS) liposomes

Photo-reactivating enzyme

extracted from a marine

plant, Anacystis nidulans

catechin, quercetin,

glycyrrhetinicacid,

endonuclease enzyme.

4. Other

delivery

systems

Iontophoresis, cosmetic patches. Vitamin C, E.

1. INTRODUCTION 38

represents smart vesicular carrier for enhanced delivery to/through skin. All components

of the Ethosomal systems are considered as being safe for pharmaceutical and cosmetic

use. Ethosomal systems were found to be significantly superior at delivering drugs

through the skin in terms of both quantity and depth when compared to liposomes and to

many commercial transdermal and dermal delivery systems. Ethosomes are sophisticated

vesicular delivery carriers that are capable of delivering various chemical applications.

Visualization by dynamic light scattering showed that Ethosomes could be unilamellar or

multilamellar through to the core. These novel delivery systems contain soft phospholipid

vesicles in the presence of high concentrations of ethanol. Ethosomal systems are

sophisticated conceptually, but characterized by simplicity in their preparation, safety and

efficiency - a rare combination that can expand their applications. 63-64

Mechanism of ethosomes

The enhanced delivery of actives using ethosomes over liposomes can be ascribed to an

interaction between ethosomes and skin. It is thought that the first part of the mechanism

is due to the’ ethanol effect’, whereby intercalation of the ethanol into intercellular lipids

increasing lipid fluidity and decreases the density of the lipid multilayer. This is followed

by the ‘ethosomes effect’, which includes inter lipid penetration and permeation by the

opening of new pathways due to the malleability and fusion of ethosomes with skin

lipids, resulting in the release of the drug in deep layers of the skin, shown in

Fig.1.4&1.5.65

Composition

The ethosomes are vesicular carrier comprise of hydroalcoholic or

hydro/alcoholic/glycolic phospholipid in which the concentration of alcohols or their

combination is relatively high. Typically, ethosomes may contain phospholipids with

various chemical structures like phosphatidylcholine (PC), hydrogenated PC,

phosphatidic acid (PA), phosphatidylserine (PS), phosphatidylethanolamine (PE),

phosphatidylglycerol (PPG), phosphatidylinositol (PI), hydrogenated PC, alcohol

(ethanol or isopropyl alcohol), water and propylene glycol (or other glycols). Such a

composition enables delivery of high concentration of active ingredients through skin.

Drug delivery can be modulated by altering alcohol: water or alcohol-polyol: water ratio.

1. INTRODUCTION 39

Figure 1.4: Drug penetration through Ethosomes

Figure 1.5: Mechanism of action of Ethosomes

1. INTRODUCTION 40

Some preferred phospholipids are soya phospholipids such as Phospholipon 90 (PL-90).

It is usually employed in a range of 0.5-10% w/w. The concentration of alcohol in the

final product may range from 20 to 50%. The concentration of the non-aqueous phase

(alcohol and glycol combination) may range 22 to 70 % .

66-67

Properties

The size of Ethosomes vesicles can be modulated from tens of nanometers to microns.

Delivery can be targeted for local delivery or for systemic use.

Ethosome allows it to carry a wide variety of molecules with various physico-chemical

properties hydrophobic, hydrophilic and amphiphilic.

Reduced doses and toxicity.

High patient compliance.

Enhancement of a product's life cycle.

Significant superiority compared to other drug delivery system.

Science behind ethosome formation

Closed lipid vesicles can be prepared from lipid multi-lamellae by strong pertrubation

that is by mechanical or chemical energy, introduced by pressure, homogenisation,

agitation, osmotic shock, with increasing lipid bilayer elasticity the energy required for

vesiculation decreases. Lipid in solvent (eg water) that contains a co-solvent (eg ethanol)

typically have rather complex (lyotropic phase diagram).The generalized phase diagram

of such system exhibits normal and inverse micellar or cubic or hexagonal phases,

seperated by central phase region in which lamellar or or vesicular phase prevail. All

such phases are sensetive to isothermal composition changes but only latter kind of

agregates-structure is practically meaningful for the colloidal mediated transdermal drug

delivery. 68

Parameters effecting bilayer formation

Large free energy difference between the aqueous and hydrophobic environment

promotes the bilayer structure in order to achieve lowest free energy level.

Driving force for bilayer configuration is the hydrophobic interaction coupled with the

amphiphilic nature of the phospholipid molecule.

Supermolecular self-assemblages mediated through specific molecular geometry.

1. INTRODUCTION 41

Ternary phase diagram

A ternary phase diagram of phosphotidylcholine, ethanol, and water reveals a complex.

In pure ethanolic solution an isotropic micellar phase is found. Addition of little water

prompts micellar elongation and crowding. Solvent content between lipid lamellae is

higher in presence of ethanol, notwithstanding the fact that alcohol replaces some water

in vicinity of phospholipid head group. The reason are the lateral and transverse

expansion of lipid bilayers caused by greater mobility of polar lipid heads, whole lipid

molecule, and bilayer segments in a hydro- alcoholic solvent mixture..This states that

ethanol increases lipid bilayer fluidity and flexibility. 68

Figure 1.6: Ternary phase diagram; L: fluid lamellar phase; I: isotropic (micellar) phase

Advantages of ethosomes

Advantages of ethosomal delivery system in comparison to other novel transdermal &

dermal delivery systems .65-73

As compared to liposomes, ethosomes are easy to prepare, store, high entrapment,

deeper permeability and enhanced delivery of active constituents

Various application in Pharmaceutical, Veterinary, Cosmetic field reported and further

developments are going on.

Ethosomes composition is safe and the components are approved for pharmaceutical and

cosmetic use.

Vesicles without use of additional surfactants to which many consumers are allergic. As

compared to others which requires lot of inputs.

Water

Ethanol SoyPC

L

I+L

L

LL

LL

LL

LL

LL

LL

LL

0.0

1 0.0

1

1.0 0.0

1. INTRODUCTION 42

Low risk profile- The technology has no large-scale drug development risk since the

toxicological profiles of the ethosomal components are well documented in the

scientific literature.

The ethosomes administered in semisolid form (gel or cream), producing high patient

compliance is high. In contrast, Iontophoresis and Phonophoresis are relatively

complicated to use that affect patient compliance.

High market attractiveness for products with proprietary technology. Relatively simple

to manufacture with no complicated technical investments required for production

of Ethosomes. Hence easy to scale up.

The ethosomal system is passive, non-invasive and is available for immediate

commercialization.

Ethosomes enhances permea tion of active constituents through skin

for transdermal and dermal delivery.

Comparative studies of existing dermal and transdermal drug delivery systems with the

Ethosome technology proved a significant superiority for ethosome over the other

technologies in terms of efficiency and lack of irritancy.

Ethosomes are platform for the delivery of large and diverse group

of drugs (peptides, protein molecules), active herbal constituents.

Ethosomes have been reported to deliver many synthetic drug for example Salbutamol

Sulfates,66

Minoxidil,75

Cannabidol,76

Acyclovir,77

AntiHIVAgents,78

zidovudine,Lamivudin

e,Trihexiphenidyl.hydrochloride79

,Insulin80

,Azelaic.acid81

,Erythromycin,82

Bacitracin,83

D

NA,84

Diclofenac,85

peptides86

. All mentioned drugs delivered through ethosomes posses

improved dermal deposition, improved intracellular delivery, bioavailability and reduced

possible side effects.

1.3.12 Topical Gel

Topical drug administration is a localized drug delivery system anywhere in the body

through ophthalmic, rectal, vaginal and skin as topical routes. Skin is one of the most

readily accessible organs on human body for topical administration and is main route of

topical drug delivery system. The skin of an average adult body covers a surface area

approximately 2m2

and receives about one third of the blood circulating through the

body. An average human skin surface is known to contain, on the average 40-70 hair

1. INTRODUCTION 43

follicles and 200-300 sweat ducts on every square centimeter of the skin. Although skin

has been divided histologically into the stratum corneum, the living epidermis and the

dermis, collectively it can be considered a laminate of barrier, permeation of this laminate

can occur by diffusion via:

Transcellular penetration (across the cells)

Intracellular penetration (between the cells)

Transappendageal penetration (via hair follicles, sweat and sebum glands).

A myriad of medicated product are applied to the skin or readily accessible mucous

membrane that in some way either augment or restore a fundamental function of a skin or

pharmacologically modulate an action in the underlined tissues. Such products are

referred as topical or dermatological product.87

Rational Approach to Topical Formulations

Topical formulation can be used to manipulate the barrier function of the skin, for

example, topical antibiotics and antibacterials help a damaged barrier to ward off

infection, sun screening agents and the horny layer protect the viable tissues from U.V.

radiation and emollient preparations restore pliability to a desiccated horny layer. For

skin appendage treatment, for example, antiperspirants, exfolients and depilatories are to

be delivered to the skin appendages. Delivery of drugs for systematic treatment, for

example, transdermal therapeutic systems provide systemic therapy for motion sickness,

angina and hypertension. Gels are becoming more popular due to ease of application and

better percutaneous absorption. The term “Gel” was introduced in the late 1800 to name

some semisolid material according to pharmacological, rather then molecular criteria.88-90

The U.S.P. defines gels as a semisolid system consisting of dispersion made up of either

small inorganic particle or large organic molecule enclosing and interpenetrated by

liquid. The inorganic particles form a three-dimensional “house of cards” structure. Gels

consist of two-phase system in which inorganic particles are not dissolved but merely

dispersed throughout the continuous phase and large organic particles are dissolved in the

continuous phase, randomly coiled in the flexible chains.

Classification

Gels are classified mainly by two methods based on:

a) Nature of colloid phase

1. INTRODUCTION 44

Inorganic gels

Organic gels

b) Based on nature of solvent

Aqueous gels

Non aqueous gels

Gel forming substances

Polymers are used to give the structural network, which is essential for the preparation of

gels. Gel forming polymers are classified as follows:

Natural polymer

Proteins: Collagen, Gelatin

Polysaccharides: Agar, Alginate acid, Sodium or Potassium carageenan, Tragacanth,

Pectin, Guar Gum, Cassia tora, Xanthan, Gellum Gum

Semisynthetic polymers

Cellulose derivatives: Carboxymethyl cellulose, Methylcellulose, Hydroxypropyl

cellulose, Hydroxy propyl (methyl cellulose), Hydroxyethyl cellulose.

Synthetic polymers

Carbomer: Carbopol 940, Carbopol 934

Poloxamer

Polyacrylamide

Polyvinyl alcohol

Polyethylene and its co-polymers

Inorganic substances

Aluminium hydroxide

Besitonite

Surfactants

Cebrotearyl alcohol

Brij – 96

Advantages

The topical administration of drug in order to achieve optimal cutaneous and

percutaneous drug delivery has recently gain an importance because of various

advantages:

1. INTRODUCTION 45

They can avoid gastrointestinal drug absorption difficulties caused by gastrointestinal

pH and enzymatic activity and drug interaction with food and drinks.

They can substitute for oral administration of medication when that route is unsuitable.

To avoid the first pass effect, that is, the initial pass of drug substance through the

systemic and portal circulation following gastrointestinal absorption, possibly avoiding

the deactivation by digestive and liver enzyme.

They are non-invasive and have patient compliance.

They are less greasy and can be easily removed from the skin.

Cost effective and reduction of doses as compare to oral dosage forms.

Localized effect with minimum side effects.91-93

Mechanism of Drug Absorption93

The rate of permeation across various layers of skin tissues in the course of topical

application can be expressed mathematically as

dQ / dt = Ps (Cd – Cr)

where dQ / dt = rate of permeation across various layers.

Cd = concentration of drug in the donar phase.

Cr = concentration of drug in the receptor phase.

Ps = permeability coefficient of the skin tissues.

The concentration in the systemic circulation which is penetrating in the form of

pharmacological active form such as:

Ps = KcDs / hs

Where Kc = partition coefficient of the penetrant molecules.

hs = overall thickness of the skin tissues.

Ds = apparent diffusivity for the steady state diffusion of penetrate moles.

If Cd >>> Cr than the equation is written as :

dq / dt = PsCd

1.4 PLANT PROFILE

The Plant Sarcostemma belonging to the family Asclepiadaceae are generally herbs,

shrubs, or rarely treelike, with milky or, less often, clear latex. Leaves are simple,

opposite or occasionally whorled, very rarely alternate, usually without obvious stipules,

1. INTRODUCTION 46

margin nearly always entire. Inflorescences terminal, axillary, or extra-axillary, cymose,

often condensed and umbel-like, occasionally a racemelike bostrychium. Flowers are

bisexual, 5-merous, actinomorphic. Sepals joined at base only, often with 5 or more basal

glands in the sinuses. Corolla sympetalous, reflexed to urceolate or salverform; lobes

valvate or overlapping in bud to right or left. Corona usually present, inserted on corolla,

stamens, or both. Stamens five, usually inserted at base of corolla tube and adhering to

stigma head to form gynostegium; filaments usually connate to form a tube enclosing

ovaries; anthers 4-celled (Periplocoideae and Secamonoideae) or 2-celled

(Asclepiadoideae), often with a membranous apical appendage; pollen tetrads contained

loosely on a spatulate translator with a basal corpusculum (Periplocoideae), or pollen

united into waxy pollinia, each attached through a caudicle (stalk) to the retinaculum

(gland) between adjacent anthers to form a pollinarium, pollinia 2 (Asclepiadoideae) or 4

(Secamonoideae) per pollinarium. Ovaries two, free, superior; ovules numerous. Styles

connate; stigma head fleshy. Fruit of one or two follicles. Seeds numerous, strongly

compressed, with a coma (a prominent basal tuft of silky hairs). Chromosome number x =

(8–)11 (or 12). Some 250 genera and over 2000 species: widespread in tropical and

subtropical regions, especially in Africa and southern South America, with a moderate

representation in northern and southeastern Asia; 44 genera (four endemic) and 270

species (153 endemic) in China.

Some authorities include this family in the Apocynaceae. Genera 1–6 are sometimes

placed in a separate family, the Periplocaceae, here regarded as a subfamily,

Periplocoideae. Genera 7–10 belong to the Secamonoideae and the remaining genera to

the Asclepiadoideae. Many Chinese taxa are known only from dried material, sometimes

not well preserved, and it is likely that the study of living or spirit-preserved material

could lead to a reassessment of the taxonomy of some of these endemic taxa.

All plant parts, especially the seeds and latex, are often poisonous. They contain various

alkaloids and glycosides, many of which are used in medicine and as insecticides. A few

succulent species (e.g., Stapelia gigantia N. E. Brown, Orbea pulchella (Masson) L. C.

Leach, and O. variegata (Linnaeus) Haworth are grown by specialist collectors in

China.94

1. INTRODUCTION 47

1.4.1 Sarcostemma

Sarcostemma is a genus of at least 35 species of plants in family Asclepiadaceae. These

are known generally as climbing milkweeds or caustic bushes. They are found across

Africa and tropical Asia, in Australia, and in parts of North America. These plants are

perennial flowering shrubs with trailing vines or lianas. They are often adapted to heat

and/or desert conditions. Leaves reduced to scales, short lived so plant is often leafless

and photosynthesize in the tissues of the green stems. The soft stems are filled with milky

white latex that is poisonous and caustic in some species. The flowers have a ring of thick

tissue at the base which extends into hollow spherical appendages within the flower

corolla.

Taxonomy of this group is controversial. Sarcostemma are widely distributed throughout

the sub-tropical and tropical old World in Africa, India and Malaysia. Several species in

this group are listed as invasive weeds and best cultivated in pots with a climbing frame,

where they can be kept under control. The milky sap is toxic and Sarcostemma australe

(Caustic Vine) blisters skin on contact. Some species may contain substance of medicinal

value.95

1.4.2 Species of the Sacrastemma include:

Sarcostemma acidum

Sarcostemma angustissima

Sarcostemma australe - caustic vine

Sarcostemma brevipedicellatum

Sarcostemma cynanchoides

Sarcostemma clausum - white twine vine

Sarcostemma decorsei

Sarcostemma esculentum

Sarcostemma hirtellum - hairy milkweed

Sarcostemma membranaceum

Sarcostemma mulanjense

Sarcostemma socotranum

Sarcostemma viminale Rapunzel plant.

1. INTRODUCTION 48

Funastrum (Sarcostemma) cynanchoides (Climbing Milkweed): Widely-distributed

across the Southern USA from Florida to California, commonly twining through shrubs,

fences and other supports. The greenish-white to pink petals are fringed with white hairs

but the stems and lanceolate to heart-shaped leaves are smooth. Flowers are followed by

pairs of pods full of seeds with silken parachutes. This plant is attractive to bees,

butterflies and birds but may be an invasive weed in some areas. .

Funastrum (Sarcostemma) hirtellum Schlechter 1914 (Hairy Milkweed): A widespread

vining plant of the lower desert in South-Western USA and North-Western Mexico. The

white petals are fringed with white hairs and the twining stems and sparse lanceolate

leaves are pubescent. May be an invasive weed, swamping other vegetation.

Sarcostemma vanlessenii Lavranos 1974: : This species from Kenya and N. Tanzania

has narrow stems up to an eighth of an inch in diameter. In a sunny location, clusters of

small pinkish to brownish flowers are produced freely during the summer.

Sarcostemma viminale R. Brown 1810: A robust species distributed acrosss Tropical and

Southern Africa. The leafless, photosynthetic stems up to a quarter of an inch in diameter

tend to explore and scramble through their surroundings, rooting as they go, but can be

confined to the footprint of a plant pot with a climbing frame and some creative basket

weaving. The cream-coloured flowers are sweetly scented. May be an invasive weed.

Sarcostemma brevistigma: A leafless East Indian vine plant with a weak stem that

derives support from climbing, twining, or creeping along a surface; its sour milky juice

formerly used to make an intoxicating drink. The herb is highly used by the rural and

tribal people in curing various disorders (fig.1.7).96

1. INTRODUCTION 49

Sarcostemma cynanchoides Sarcostemma hirtellum

Sarcostemma vanlessenii Sarcostemma viminale

Sarcostemma acidum Sarcostemma acidum

Figure 1.7: Species of the Sacrastemma

1. INTRODUCTION 50

1.4.3 Sarcostemma brevistigma Wight & Arnott

Asclepias acida Roxburgh, Fl. Ind. ed. 1832, 2: 31. 1832;

Sarcostemma acidum (Roxburgh) Voigt, Hort. Suburb. Calcutt. 542. 1845,. belonging to

family Asclepiadaceae. Stem 2-5 mm diameter, glabrous, joints 10-20 cm long.,leaves

reduced to scales, shor lived so plant is often leafless, Leafless trailing or twining jointed

shrubs with pendulous branches.,Flowers in sessile many flowered terminal umbels;

pedicles 6-8 mm long, slender, pubescent, bracts minute, lanceolate.,Calyx divided to the

base or nearly so, with glands inside, segments 1.25 mm long, ovate-oblong, subacute,

with membranous margins.,Corolla campanulate, pale greenish white, divided nearly to

the base, lobes 5 mm long, ovate oblong, subacute, outer corona crenately 10-lobed on

the margin, lobes of the inner corona thick, fleshy, obtuse, longer than the staminl column

almost concealing the anther. Stamina column very short, pollen-masses waxy,

compressed, clavate, slightly curved, attached by a very short caudicle to the pollen

carriers. Style-apex very shortly conical or blunt. Follicles 10-12.5 by 0.8 cm, lanceolate,

tapering to both ends, straight, slightly diverging when two together. Seeds 5 by 3 mm,

ovate, flattened, coma 2 cm long.

S. brevistigma leafless East Indian vine plant with a weak stem that derives support from

climbing, twining, or creeping along a surface; its sour milky juice formerly used to make

an intoxicating drink.The herb is highly used by the rural and tribal people in curing

various disorders.

On the basis of well designed open ended questions tool a study performed in central

region of Madhya Pradesh, India and enumerates various traditional and ethnomedicinal

utility of the plant. It has been concluded that somlata herb(comman name) was used in

various diseases such as asthma, swelling, fever and cold, dyspepsia, inflammation

infection and gastric problem etc.

Common Name: Somavalli, haoma, soma.

Synonyms :

Bengal : Soma, Somlata

Bombay : Lama, Soma

Canarese : Brahmi, Hambukalli, Somaballi, Somalate, vasukanti

English : Moon Creeper, moon plant, Sour Creeper

1. INTRODUCTION 51

Gujerati : Somvel

Hindi : Somlata

Koya : Kadujemudu

Malayalam : Somam, somavallari, Somavalli, Vayastha

Marathi : Ransher, Ransheryel, Somyel

Mundari : Kulatoa

Porebunder : Chirodi Sandhiavelm,Thoravel

Sanskrit : Chandravallari, Dhanurlata, Dvijapriya, gulmavalli, Indulekha, Mahagulma,

Padmakashtha, Soma, Somakshiri, Somalata, Somhara, Somavalli, Somavallika,

Yajnaga, Yajnashreshtha, Yajnavalli

Sind : Thorinjal

Sinhalese : Muwakiriya

Tamil : Kodikkalli, Somam

Telugu :Kondapala, Padmakashtamu, Pullajemudu, Pollatige, Somlata,

Tigejemudu, Pullangi tiga

Uriya : Borohwi, Notasiju, Somolota

Geographical source : Some 250 genera and over 2000 species: of Asclepiadaceae

widespread in tropical and subtropical regions, especially in Africa and southern South

America, with a moderate representation in northern and southeastern Asia; 44 genera

(four endemic) and 270 species (153 endemic) in China.

S. bevistigma distributed in various parts of India it is found in dry rocky places in Bihar,

Bengal, Konkan, Deccan, Tamil Nadu, Maharashtra, Kerala, Chota Nagpur, Burma, N.

Circars, and Carnatic.97,98

Sarcostemma acidum as an Indian Soma :

Vedic literature supports that Soma was a sacred plant, the juice of which (Soma-Rasa)

was considered as the divine drink offered to Gods, contemplated with medicinal

efficacy, used as natural restorative for health that makes the consumer awakened and

alert. As a matter of fact, the Rig Veda describes how the marvelous drink was prepared:

the dried Soma plants were moistened with water to make them swell up again and

pounded with pestles. After being filtered through a fine woollen cloth, the tawny yellow

inebriating juice was imbibed by the Vedic priests in their sacrificial rites. The effects, as

1. INTRODUCTION 52

these emerge from the poetic imagery of the hymns, were clearly what we would now

call hallucinogenic or psychedelic.

Soma is known to most readers as the stimulant, euphoriant and hallucinogen in Aldous

Huxley's novel Brave New World. Few people know that the plant soma actually exists

and has been used as a narcotic since the time of India's earliest civilizations. In Ancient

Indian mythology Soma, the brother of Indra, was the giver of health, courage, long life,

a sense of immortality, and almost every other virtue known. As a narcotic, soma is

thought to have originated in the Hindu Kush mountain range of northeast Afghanistan.

Nor is there evidence that Sarcostemma has psychoactive properties, particularly of the

kind implied in such Vedic hymns as one that speaks of the priestly imbiber of the divine

Soma having the power of flight beyond the limits of heaven and earth and feeling strong

enough to pick up the earth itself and move it about wherever he desired. An modern

Hindu tantric practices in the southern state of Kerala, however, Soma is a different

quantity. It is described in the book “Agni by Frits Stall” that the botanical name of Soma

is `Sarcostemma brevistigma`. It is a creeper(vine) that is commonly found in the

Western Ghats of South India. The stem is used to make the Somarasa for many yagas in

Kerala. The King of Kollengode, an erstwhile principality in Kerala, is obliged to supply

the soma stems for yagas.

Sarcostemma brevistigma is used in India today under the name soma, as are several

other plants including Ephedra species. It may be that all of these are surrogates, or it is

quite possible that Sarcostemma bievistigma is the plant soma of antiquity. A thorough

chemical analysis of the latter to establish the presence of an intoxicating narcotic is in

order. It is known that the dried stem is an emetic in Indian medicine, but knowledge

about fresh milky latex is required Certainly the herb is worthy of more investigation than

has been conducted to date. In a volume entitled Medicinal, Economic, and Useful Plants

of India by Sudhir Kumar Das, the foreword notes that the "therapeutic uses of plant

materials have been quoted from records of the findings made through the ages by Hindu

Ayurvedic Pharmacists." In this compendium of ancient sources, Sarcostemma

brevistigma is listed with the following note: "Herb. Plant juice is intoxicating and blood

purifying." Such evidence is only circumstantial, but most intriguing.99

1. INTRODUCTION 53

1.4.4 Active Constituents

Phytochemical Studies have revealed the presence of Bergenin, Brevine, Brevinine,

Sarcogenin, Sarcobiose and Flavonids (Obeai et al 1985). The aerial Parts of

Sarcostemma acidum has shown various Pregnane glycoside which are diglycosides and

triglycosides. Some important pregnane glycosides are:- Sarcogenin (triglycoside),

Brevobiose (disaccharide), Sarcobiose (nonreducing disaccharide), Tigmobiose (non

reducing disaccharide), Brevine (triglycoside), Brevinine (Pregnane ester diglycoside)

Brevine: Brevine is a pregnane ester triglycoside isolated from the dried twigs of

Sarcostemma brevistigma. Its chemical and spectroscopic properties were consistent with

the structure 11-O-benzoyl-sarcogenin-3-O-α-L-diginopyranosyl (1 → 4)-O-α-L-

diginopyranosyl(1 → 4)-O-α-L-diginopyranoside.

Sarcobiose: It is a nonreducing disaccharide, isolated from dried twig of Sarcostemma

acidum. Its structure has been established as 3,4-anhydro-2,6-dideoxy-β-D-lyxo-

hexopyranosyl 6-deoxy-3-O-methyl-β-D-allo-pyranoside.

Figure 1.8: Chemical structure of Brevine Figure 1.9: Chemical structure Sarcobiose

1. INTRODUCTION 54

Brevobiose: It is disaccharide, isolated from the twig of Sarcostemma acidum. Its

structure has been established as 4-O-(6-deoxy-2-O-methyl-β-D-allopyranosyl)-D-

boivinose.

Figure 1.10: Chemical structure Brevobiose

Tigmobiose: It is non reducing disaccharide, isolated from the dried twigs of

Sarcostemma acidum. Structure has been established as 2,6-dideoxy-β-D-ribo-

hexopyranosyl 2,6-dideoxy-β-D-ribo-hexopyranoside (β-D-digitoxopyranosyl β-D-

digitoxopyranoside).

Figure 1.11: Chemical structure Tigmobiose

Sarcogenin : It is a pregnane genin, isolated from Sarcostemma acidum and has been

characterized as 13β,8β,11α,14 β,17 β -hexahydropregn-5en-20-one.

Figure 1.12: Chemical structure Sarcogenin

1. INTRODUCTION 55

Brevinine: It is a Pregnane ester diglycoside, isolated from the dried twigs of

Sarcostemma breoisrigma and has been characterized as 11-O-benzoyl-sarcogenin-3-O-

α-L-diginopyranosyl(1→4)-α-L-diginopyranoside.

Its chemical and spectroscopic data are consistent with structure -

Figure 1.13: Chemical structure Brevinine

Bergenin :It is trihydroxybenzoic acid glycoside. It is the C-glycoside of 4-O-methyl

gallic acid. It possesses an O-demethylated derivative called norbergenin. These are

chemical compounds and drugs of Ayurveda.Chemical Structure of Bergenin is-

(2R,3S,4S,4aR,10bS)-3,4,8,10-tetrahydroxy-2-(hydroxymethyl)-9-methoxy-3,4,4a,10b-

tetrahydro-2H-pyrano[3,2-c]isochromen-6-one.

Bergenin have various activity like Anti-inflammatory (T.Swarnalakshmi et al.1984),

Fever reducer, Obesity and Hepatoprotective activity (Xuan QIN et al 2010). It decongest

the airways and stimulates the bronchial secretion.It liquefies the mucus and enhances

expectoration.It strengthens immunity system against all type of cold. But still research is

necessary for Sarcostemma acidum herbal plant.

Figure 1.14: Chemical structure Bergenin

1. INTRODUCTION 56

Carbohydrates : The plant also contain carbohydrates, viz free sugars, water-soluble

polysaccharides, starch, pectins, gums and mucilages, hemicelluloses and cellulose.A

homologous series of alkanoic acid (C2–C5) esters of germanicol has been isolated from

the methanolic extract of Sarcostemma acidum.

The Sarcostemma plant species are potential sources of hydrocarbons. Large-scale

screening of plants growing in the Western Ghats, Tamil Nadu, India was conducted to

assess the hydrocarbon production and the type of isoprene compound(s) present.

Sarcostemma brevistigma had the highest concentration of hydrocarbon with 3.6% (trans-

polyisoprene). Disacchariditol, sarcidumitol, has been isolated from the water-soluble

fraction of the 95% ethanol extract of the plant Sarcostemma acidum

Four lignans, sacidumlignans A−D :

Four lignans, sacidumlignans A−D (Fig:1.15) The structures and relative configuration of

these new compounds were elucidated on the basis of spectroscopic and chemical data,

especially 2D NMR techniques. Sacidumlignan D was assigned as a rearranged

tetrahydrofuran lignan with an unprecedented skeleton. Sacidumlignan A showed

moderate antimicrobial activities against two Gram-positive bacteria in vitro.

taraxasterol, multiflorenol, and bauerenol were also isolated for the first time from the

genus Sarcostemma acidum100-105

.

1.4.5. Pharmacological Action

Sarcostemma acidum has been reported to possess a strong array of various

Pharmacological action such as: Antiinflammatry activity, Analgesic activity,

Antiarthritic Activity, Spasmolytic activity, Tocolytic activity, Anti-asthmatic,

Figure 1.15: Chemical structure of Lignans of sacidumlignans A−D

1. INTRODUCTION 57

Antiallergic activity,Bronchospasmolytic activity, Hepatoprotective activity,

Spermatogenesis, Larvicidal acivity, Immunity, C.N.S. depression, Antimicrobial

activity, Anti-Syphilitic and Anthelmintic Activity and Antioxidant Properties.106-121

1.4.6 Ethnomedical Uses of S. brevistigma

Source of hydrocarbons

Plant species are potential sources of hydrocarbons. Sarcostemma brevistigma may be

use as a source of biomass fuel. (Augustus et al. 2002) estimate the potential hydrocarbon

in selected species of Western Ghats, Tamil Nadu, which show that Sarcostemma

brevistigma has the highest concentration of hydrocarbon of 3.6%. While species such as

Tylophora asthmatica, Euphorbia tirucalli, Cryptostegia grandiflora, Ficus ealstica and

Euphorbia antisyphylitica contained more than 2%. The gross heat value of hydrocarbon

fraction in Sarcostemma brevistigma is 8733 Cal/g, which is comparable to fuel oil

calorific value. This study showed the significant importance of this plant in light of the

decline in global supplies of hydrocarbons, which has led to a search for alternate sources

of fuels.122

Use in inflammation

S. brevistigma is used in the treatment of swelling and inflammation condition. The

boiling water of S. brevistigma use to cure swelling. This ethnobotanical studies were

carried out by Y.S.patel et al. in Tapkeshwari hill of Bhuj Taluka (Kachchh district,

India) by collect information on the use of medicinal plants by local communities.

In The Treatment of Arthritis

S. brevistigma is used in the treatment of Arthritis. Whole part of plant crushed and made

to powdered given with water in case of asthma. Samir K Shah et. al. investigated the

antiarthritic activity stem of Sarcostemma brevistigma in experimental animals.123

In The Treatment of Preterm Labour

Sarcostemma brevistigma exhibits uterine relaxant activity, by interfering with the

extracellular Ca 2+

(P Suresh Kumar et al. 2006). This tocolytic activity of S.brevistigma

used in treatment of preterm labour. The major cause of perinatal morbidity and

mortality, is preterm labour. During term, oxytocin (OT) and prostaglandins act on the

uterus, and induce contractions, that result in preterm labour. OT binds to the specific

receptors, and increases the intracellular Ca 2+

level through release of Ca 2+

from both

1. INTRODUCTION 58

sarcoplasmic reticulum via inositol-1, 4, 5-triphosphate (IP3) pathway, and extracellular

fluid through voltage operated calcium channels. Preterm labour has been conventionally

treated with calcium channel blockers, OT antagonists, b 2-agonists, magnesium sulphate,

and prostaglandin synthetase inhibitors. However, these drugs are sometimes inadequate,

and have adverse effects like tachycardia, increased cardiac output, pulmonary edema,

hyperglycemia, cardiac depression, and inhibition of neuromuscular transmission.110

Asthma

According to folklore, this plant extract is used for the treatment of asthma. 124

Cough, chronic and acute bronchitis

S. brevistigma have bronchospasmolytic activity because it inhibited the contractions

induced by acetylcholine and histamine on animal. And for bronchospsmolytic activety it

have antitusive properties and used in cough, congestion of the upper respiratory tract,

asthma, chronic and acute bronchitis. Its antiinflammetory property also help to relief

pain in dry cough condition.125-126

Used in treatment of Cold

According to folklore of Tribals of Sriharikota Island, Andhra Pradesh it is used to relief

from cold,10-15 ml of fresh stem juice slightly warmed administered orally to children

for 4-5 days to get relief from cold.

Cataract

According to folklore of Tribals of Sriharikota Island, Andhra Pradesh, Latex of

S.brevistigma dropped into eyes in case of early stages of cataract (Suklamu).127

In preparation of male contraceptive pills

In medieval Persia various herbs were used for male contraception, Sarcostemma acidum

(Asclepiadaceae) is one of that drugs. However, the compound isolated from Gossypium,

as well as other cotton seeds and okra (gossypol) has been abandoned as for contraceptive

use because it was found to cause permanent infertility in ten to twenty percent of users.

Multiple male hormonal contraceptive protocols have been developed. One is a

combination protocol, involving injections of Depo-Provera to prevent spermatogenesis,

combined with the topical application of testosterone gel to provide hormonal support.

Sarcostemma acidum has property of preventing spermatogenesis.115

1. INTRODUCTION 59

Rejuvenation

S. brevistigma strengthens the immunity system against all types of cold. It is used in

general debility, mental disorders, to rejuvenate the mind and senses, and have attributed

mood-enhancing properties to help alleviate stress, depression and insomnia. Combined

with healthy diet, regular exercise, and lifestyle measures such as meditation, S.

brevistigma helps to promote mental and emotional wellness.Quantum adaptogen

complex containing S. bevistigma have been used for thousands of years for that

purpose.122

Burning micturation

C.Sudharkar Reddy et al. Studied in traditional medicinal plants in Seshachalam hills

Andhra Pradesh, India and giving the ethno medicinal use of sarcostemma acidum that it

is use during burning maturation (A teaspoonful of plant powder administered with two

cups of toddy). 127

Milky juice is anti-syphilitic and anthelmintic

Some articles state that milky juice of S. brevistigma is used as a anti-syphilitic and

anthelmintic however farther scientific study is necessary.128-129

Root have been used in snack bite and rabies

A.S.Wabale et al. studied on the basis of aquestionnaire prepared containing the

information about the tribals, their living style, source of income, ethnomedicinal uses of

plant species and their style of treatment with references of tribal vaidyas of Kalsubai and

Ratangad and concluded that S. brevistigmma was used externally as a ethnomedicinal

plants in the treatment of dog and different animal bites. There is need for further

scientific research.130

Dyspesia and other gastric problem

Powder part is given twice a day with cow milk or Luke water as remedy for gastric

problems.131

1.4.7 Marketed Product

Various marketed product are available of sarcostema acidum for treatment of different

diseases which are shown in Table.1.2 and fig.1.16. 132-141

1. INTRODUCTION 60

Table 1.2: Marketed products containing Sarcostemma acidum herb

S.No Marketed

Product

Ethnomedical Uses

1. Coughend, Cofdar

Syrup and Quote

Capsule

All types of cough (dry, productive, gasp) and is also a

stimulant of bronchial secretions.. .

It decongests the airways, stimulates the bronchial secretions.

It is good as a complementary therapy in acute and chronic

bronchitis and in asthma therapy.

2. Sewanti Stressnil Used to treat mental stress, depression, and insomnia.

3. Koflin Syrup Cough of allergic, infective or asthmatic origin, Cough

associated with gastro-esophageal reflux, Cough caused by

dusts, Cough of TB, Bronchial asthma

5. Asthalab Tablet

For Smokers cough, allergic, seasonal cough, and spasmodic

cough.

7. Kashin Syrup It also provides quick and long lasting relief from coughs and

sore throat. .

It provides bronchodilator activity and offers an antimicrobial

and anti-inflammatory action on the respiratory system.

8. Ecasma Tablet Used in Bronchitis, Laryngitis, Respiratory tract infection,

Nasal congestion, Cough and Asthma

9. Spasma Syrup Used in cough of allergic, infective or asthmatic origin,

cough associated with gastro-esophageal reflux, cough

caused by dusts, cough of TB, bronchial asthma.

10. Shankof Syrup Productive Cough & Non Productive Cough .Bronchitis.

Asthma, Whooping Cough, Lung Infection, Dry Cough,

Wheezing.

12. Vikas Amrit It is very effective in reducing overweight and obesity

13. Nakas Syrup For asthmatic cough it reduces mucosal irritation in the

respiratory tract in non productive cough

1. INTRODUCTION 61

(a) (b) (c) (d)

(e) (f) (g)

Figure 1.16: Marketed product containing S.acidum herb

(a),Coughend Syrup,(b)Stressnil Syrup,(c) Kflin Syrup,(d) Quantum adaptogen complex capsule,

(e) Asthaleb tablet, (f) Vikas Amrit capsule, (g) soma complex.

1. INTRODUCTION 62

1.4.7 Conservation and Cultivation Practices

The need for conservation of Sarcostemma acidum medicinal plants

The use of medicinal plants as raw materials in the production of new drugs is ever

increasing because of their potentials in combating the problem of drug resistance in

micro-organisms. Demand for medicinal plants is increasing in both developing and

developed countries. Research on medicinal plants is one of the leading areas of research

globally. However, there is a need to pay closer attention to the issue of conservation of

medicinal plants.

Somlata (Sarcostemma acidum) belonging to the family Asclepiadacea grown in India,

Europe and US is an underutilized crop. The herb is highly used by the rural and tribal

people in curing various disorders such as asthma, swelling, fever and cold, dyspepsia,

inflammatory infection, gastric problems and as rejuvenating .There is a great need to

conserve these medicinal plants because they contain highly bioactive components which

can be developed into pharmacologically active agents. The plant is widely used in the

treatment of various diseases and disorders, so there is need for necessary conservation

of this plant.

Reasons to become endangered species

1. The use of S.acidum is reducing day by day because people decline to walk long

distances to collect them and also lack of knowledge.

2. Rising number of human and animal population which causes pressure on plant

survival. Human agricultural activities result in clearing of natural habitats for

farming and grazing, trees are felled for timber, charcoal and other commercial

uses and lands are used in a way that are not sustainable.

3. Popularity of Sarcostemma brevistigma has decreased now.

4. Due to modernization and destruction of natural habitat.

5. Due to biotic interference

6. Fungal growth on the plant which deplete the species.

Need of bioactivity-safety evaluation of Sarcostemma acidum

Sarcostemma brevistigma Wight (family Asclepiadaceae) grows throughout India and

other tropical regions of the world. It is found to be active as anti-rheumatic, anti-allergy,

anti-emetic and branchodilator. Phytochemical studies reveal the presence of bergenin,

1. INTRODUCTION 63

brevine, brevinine, sarcogenin, sarcobiose and flavonoids2–4. The plant is having many

chemical constituents viz glycosides, flavonoids hydrocarbons, alkaloids, etc. These

secondary metabolites have some therapeutic effects. To know the effects of the chemical

constituents some test are done that are known as biological testing. The drug or chemical

constituent show their effect at some concentration which is not harmful to the human.

The concentration at which the drug or chemical constituent show its therapeutic effect is

known as therapeutic dose or effective dose of that drug. If the dose is more than its

therapeutic dose it may cause side effects or toxic effects. To know about the safety of

drug to the human is known as bioactivity-safety evaluation of the drug. To know the

effective dose of the drug and toxic effect of the Sarcostemma acidum bioactivity-safety

evaluations are done142-148

1.4.8 Popularity of Sarcostemma acidum over time

The popularity of Indian soma S. acidum has decreased which is shown graphically by

Australian new crops web site. Graph is plotted between the numbers of papers and year

(1926 to 2006),(Fig.1.17).149

Figure 1.17: Popularity of S.acidum

1. INTRODUCTION 64

1.4.9 Cultivation Practices

Humanities rely on a diverse range of cultivated species. It is often stated that only a few

staple crops produce the majority of the food supply. Several countries in the world have

a rich heritage of herbal drugs, very few can put claim for their procurement only from

cultivated species. It is recently that some of these drugs have been subjected to

systematic cultivation based on modern scientific information (Getinet et al., 1996). Our

reliance on wild sources of crude drugs and the lack of information of sound cultivation

technology have resulted in gradual depletion of raw materials from wild sources.

The wealth of India is stored in the enormous natural flora which has been gifted to her.

Endowed with diversity of agro-climatic conditions, India is virtually herbarium of the

world. India possesses all types of climatic conditions varying from north to south.

Because of vast area and variety of agro-climates, a large number of medicinal and

aromatic plants are found growing wildly and has been considered as “Botanical Garden

of the World” and this botanical wealth constitutes more than 2200 species of medicinal

and essential oil containing plants. (Kokate et al., 2005).

Cultivation is frequently advocated as a measure to take pressure of wild stocks

especially for species collected in large quantities for trade. It can be commercially

attractive to companies because they have greater control over quality and supply.

Various factors influence the feasibility of cultivation. The best way to provide the plant

material needed for medicine is to cultivate the plants. Cultivation of medicinal plants is

one of the major mechanisms by which conservation, sustainable harvesting as well as

utilization can be drawn simultaneously. With the increasing demand of natural resources

in the world, cultivation of medicinal plants will be more profitable than cultivating

conventional cash crops. Thus, it becomes essential to generate the knowledge of

agronomics and make the same available to the farmers with agricultural technologies

(Verma et al., 2007).

Protein, carbohydrates, vitamins and fats are the main constituents of our diet. Oil is an

important source of fat and is important in human diet. Beside this, oil plays a vital role

in maintaining the agricultural economy of the country. The necessity for providing more

oil and fat to the human society has been the incentive for intensive cultivation of crops.

Scientists are working in this field to search out natural sources of oil crop’s containing

1. INTRODUCTION 65

various drugs of medicinal importance. Their sole aim has been to have better yield.

Later, as a result of more and more appreciation of oil in our daily food, they have

unavoidable place in man’s economy. As a matter of facts, the interest in production of

oil crops has increased tremendously in recent years (Kumar, 1992).

The general cultivation practices of S. acidum are given below (Table 1.3)150-154

: (as per

Dwivedi 2010)

Table 1.3: Cultivation practices of S. acidum

S/No. Parameters Requirements

1. Method of propagation Stem cutting

2. Size of stem cutting 4-6 inch

3. Nature of soil Loamy –sandy

4. Irrigation Very less amount of water is required

5. Light range Partially

6. pH range 5-8

7. Water range Dry

8. Temperature Moderate to low

9. Bloom time Early Summer

10 Fertilizers Generally fertilizers are not required

11. Phyto-hormones Addition of IAA and GA3 will

increase the aerial growth of the plant

Addition of Ethylene will promote the

more number of flowers

12. Pesticides Generally malathion or other anti-

fungal agents may be spread to avoid

the growth of fungus in the plant.

13. Weedicides Normally not required