vol 3 - cont. j. pharmcol. tox. res

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Continental J. Pharmacology and Toxicology Research 3: 1 - 4, 2010.

Wilolud Journals, 2010.

PHYTOCHEMICAL SCREENING AND ANTIBACTERIAL ACTIVITY OFAginanthus brunneus EXTRACTS

V.O Aina, H.M Inuwa , Sani Ibrahim and D A Ameh

Department of Biochemistry, Ahmadu Bello University, Zaria - Nigeria.

ABSTRACT

Aginanthusbrunneus is a specie of Africa mistletoe and is hemiparasitic in nature growing on

many trees. Phytochemical screening showed the presence of carbohydrates, Alkaloids,

Tannins and flavonoids. The ethanolic and aqueous extracts inhibited growth of Klesiella

aerogenes, Proteus spp Escherichia coli, Pseudomonas aeruginosa. Gentamycin and

Cloxacillin did not exhibit any activity against Pseudomonasaeruginosa.

KEYWORDS: Aginanthus brunneus, parasitizing, Adventitous roots, Suckers, Dispersal,

Decoction.

INTRODUCTION

The plantAginanthus brunneus is a specie of Africa mistletoe and belongs to the Loranthaceae family. It is a partial

parasite found growing on the branches of other trees. This particular species was found and chosen from the

Botanical garden of Ahmadu Bello University parasitizing onAlbizzalebbeck(see Fig. 1).

Being a parasite, it is therefore unable to acquire all the nutrient it needs by its own independent processes and hence

takes what it needs from its living host through special sucker-like outgrowths which penetrate the tissues of the host

plant.Aginanthus brunneus is a shrubby green-leaved, partial parasite living attached to the branches of trees andshrubs in forest. It also parasitizes on trees scattered over a wide range of vegetation. The plant is attached to its host

by means of suckers usually regarded as modified adventitious roots, resulting in a large outgrowth where the

parasites roots enters the host tissue and the root often branches considerably within the host (Richardson, 1978).

The plant has small tough green leaves but still draws a proportion of its nutrients from its host (Nielson, 1965). The

plant also has cluster of narrowly tabular flowers, often brightly coloured. It also has fruits which are often reddish

brown containing seeds in sticky pulp, attractive to birds feeding on the fruits, thereby aiding in their dispersal

(Richardson, 1978). The seeds are known to germinate in the cracks of the bark of a great variety of trees (Nielson,

1965).

There is increasing evidence that it threatens the establishment of trees on which this parasitic plant parasitizes

(Richardson, 1978) and is known to grow on various trees in Nigeria. In the Northern part of the country, it is found

Figure 1:Aginanthus brunneus (circle) parasitizing


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V.O Aina et al.,: Continental J. Pharmacology and Toxicology Research 3: 1 - 4, 2010.

growing on the fruit trees and various woody trees common in the northern vegetation which are not annuals such asthe eucalyptus family, thus this parasitic plant is ubiquitous in distribution.

The extracts from the leaves of this plant stimulate insulin secretion from pancreas cells and help in the treatment of

arthritis (Blumenthal et al, 1998). Earlier research has also shown that the leaf contains choline, acetylcholine,

lectins, polypeptides and polysaccharides. Studies have also shown that Aginanthus brunneus alkaloids can help to

kill cancer cells both in vivo and in vitro (Khwaja et al, 1986). The decoction of the leaves is one of the most

effective extracts used in treating high blood pressure in man, epilepsy and other nervous conditions (Gill, 1992).

AIMS AND OBJECTIVES OF THE RESEARCH

1. To find out the natural products in the plant specie.

2. To investigate the Antibacterial/Antimicrobial efficacy of the plant.

MATERIALS AND METHODS

Fresh leaves ofAginanthus brunneus were collected from the trunk of Mahogany in Ahmadu Bello University Zaria

Botanical garden and were identified at the herbarium Biological Sciences Department of ABU Zaria with a

Voucher Number 6984.

Preparation of Extracts

Fresh leaves were sun dried for about 2 weeks and macerated into a powder form.

A 100g each was extracted separately using 500ml distilled water and 90% ethanol as solvent. The solvent

extraction lasted 72h at room temperature (25oC). The crude extracts were concentrated to give 40g of ethanolic and

65g of aqueous extracts.

Test Microorganisms

Five bacteria species were employed as test microorganisms. These include; Staphylococcus aureus, Klebsiella

aerogenes, Proteus spp, Escherichia coil and Pseudomonas aeruginosa. These were sourced from theMicrobiological unit of the Department of Applied Sciences, Kaduna Polytechnic, Kaduna and maintained on

Muller Hinton slants at 40C before testing.

Antibacterial Screening/Assay

Each test organism was cultured and incubated for 4h. These were used to inoculate plates of Muller Hinton agar.

The disks containing the different crude extracts were transferred using sterilized forceps to the agar plates. Sterile

water and 95% ethanol were used as control. Standard antibiotic disks were used for comparison. The plates were

incubated at 35oC for 36h before the examination for zones of inhibition of growth.

Phytochemical Analysis

The extracts were subjected to analysis for the presence of saponins, steroids, alkaloids, flavonoids, tannins,

carbohydrates, lipids and terpenoids using the standard method of (Harborne, Trease and Evans 1978).

RESULTS AND DISCUSSION

Table 1: Phytochemical analysis of the crude extracts of the leaves ofAginanthusbrunneus

Class of Product

Extract Saponins Steroids Flavonoids Tannins Alkaloid Terpenoids Liqids

Aqueous

Ethanolic

-

-

+

+

+++

+++

+++

+++

-

-

+++

+++

-

-

Key +++ = Present, + = Weakly present, = Absent


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Table 2: Antibacterial activity and zone of inhibition (mm) of the leaf of Aginanthus brunneus extracts zone ofinhibition (mm).

Extract Staphylococcus

aureus

Klebsiella

aerogenes

Proteus

species

Escherichia

coli

Pseudomonas

aeruginosa

Ethanol - 11.60 12.00 7.00 9.00

Aqueous - 13.00 13.00 9.00 10.00

Gentamycin 12.0 11.50 14.00 18.50 -

Cloxacllin 9.0 12.50 10.50 8.50 -

95%

Ethanol

(Control)

- - - - -

Deionized

water(control)

- - - - -

Table 1 shows the result of preliminary phytochemical analysis. The results obtained indicated the presence of

tannins, alkaloids, flavonoids, carbohydrates. Terpenoids, lipids and saponins were absent.

The crude extracts (ethanolic and aqueous) of the leaf were heated with concentrated hydrochloric acid and

magnesium turnings giving a red colouration indicating the presence of flavonoids.

From the results of Table 2: None of the extracts inhibited Staphylococcus aureus, Pseudomonas aeruginosa was

resistant to both Cloxacillin and Gentamycin.

Other tests such as susceptibility test showed that the cold aqueous and ethanolic extracts had similar activities on

the test organisms, although cold aqueous extract had a slightly high inhibition zone than the ethanolic extract. The

antibacterial activity of Aginanthus brunneus extracts correlated well with its traditional use (Pamplona-Roger,

1999).

Furthermore, the antibacterial activity of the extract compared favourably well with standard antibiotic used in this

work namely (Gentamycin and Cloxacillin).

This work has shown that this specie of Africa mistletoe (Aginanthus brunneus) contained many classes of natural

products namely: Flavonoids, carbohydrates, tannins and alkaloids. Both aqueous and ethanolic extracts were shown

to be active against Pseudomonas aeruginosa, Escherichia coli, Proteus spp, and Klebsiella aerogenes.

REFERENCES

Blumenthal, M., Busse W.R, and Goldberg, A., (1998);Therapeutic guide to herbal medicine. The complete

German Commission. E. Monogr., 171:2-3.

Gill, L. S., (1992): Globimetulla browni. Ethnomedical uses of plants in Nigeria. University of Benin Press, BeninPp: 244 245.

Khwaja, T.A, Dias, C.B., Pentecost, S. (1986): Recent studies on the anticancer activities of some species of

mistletoe and its alkaloid.Aucology, 3:1 10.

Neilson, M. S (1965):Introduction to the flowering plants of West Africa. University of London Press. Pp 28 31,

101 106.

Pamplona Roger, G. H; (1999): Medicinal plants; Encyclopedia of Medicinal plants. Safeliz Publication. Spain,

Pp: 245 247.

Richardson I. B K (1978): Lorantheceae (Mistletoe) in flowering plants world(Heymond V. H et al Edn.) Oxford


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University Press, Oxford, London, Melbourne, Pp. 174 175.

Harborne, Trease, G. E and Evans, W. C. (1978): Pharmacognosy. 11th

Edn. Bailner Tindall Ltd, London, Pp: 784.

Received for Publication: 05/06/2010

Accepted for Publication: 09/07/2010

Corresponding Author:

V.O Aina

Department of Biochemistry, Ahmadu Bello University, Zaria - Nigeria.

E-mail: [email protected]

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