diuretic effects of selected thai indigenous medicinal plants in.pdf

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Journal of Ethnopharmacology 75 (2001) 185190

Diuretic effects of selected Thai indigenous medicinal plants inrats

Bungorn Sripanidkulchai a,*, Varima Wongpanich b, Pisamai Laupattarakasem a,Jamsai Suwansaksri c,1, Dusit Jirakulsomchok a

a Faculty of Medicine, Khon Kaen Uni6ersity, Khon Kaen 40002, Thailandb Faculty of Pharmaceutical Sciences, Khon Kaen Uni6ersity, Khon Kaen 40002, Thailand

c Faculty of Associated Medical Sciences, Khon Kaen Uni6ersity, Khon Kaen 40002, Thailand

Received 26 April 2000; received in revised form 18 September 2000; accepted 25 December 2000

Abstract

Extracts of five indigenous Thai medicinal having ethnomedical application in the treatment of dysuria were investigated for

their diuretic activity. Root extracts of Ananas comosus and Carica papaya, given orally to rats at a dose of 10 mg/kg,

demonstrated significantly increased urine output (PB0.01) which was 79 and 74%, respectively, of the effect of an equivalent

dose of hydrochlorothiazide. Both plant extracts gave similar profiles of urinary electrolyte excretion to that of the hydrochloroth-

iazide. The analyses of the urinary osmolality and electrolyte excretion per unit time suggest the observed effect ofA. comosus was

intrinsic, whereas that of C. papaya may have resulted from a high salt content of this extract. However, our experimental

evidence on the diuretic activities of the other three plants did not parallel their local utilization for dysuria. It was found that

the rhizome of Imperata cylindrica apparently inhibited the urination of rats whereas the rhizome ofCyperus rotundus and thestem of A6errhoa carambola failed to demonstrate any diuretic activities. These results indicate that two of the plants investigated

exert their action by causing diuresis. The other three plants need further investigation to determine their effectiveness in the

treatment of dysuria. 2001 Elsevier Science Ireland Ltd. All rights reserved.

Keywords: Herbal medicine; Medicinal plant; Diuretic activity; Diuresis; Dysuria

www.elsevier.com/locate/jethpharm

1. Introduction

Sripanidkulchai et al. (2000) listed 13 plants em-

ployed by local practitioners in the district of Pon for

the treatment of dysuria. This symptom is common to

the Northeast of Thailand, and most of the cases are

related to the medical findings of renal stone.

Chemotherapy is mainly symptomatic, and based on

the use of diuretics, as well as antibacterial and/or

anti-inflammatory drugs. Certain plants with an eth-

nomedical reputation of diuresis, such as Tribulus ter-

restris and Pluchea indica, were previously reported to

increase urine output in rats (Nilveses et al., 1988,

1989). However, there was no experimental record on

the diuretic activity of the 13 plants listed above. This

present study aimed to evaluate the diuretic activity of

the aqueous extracts of the top five listed plants inorder to relate the efficacy of those plants with their

ethnomedical uses.

2. Materials and methods

2.1. Plant materials and preparation of the extracts

The top five plants used as traditional medicines for

the treatment of dysuria in Khon Kaen province were

investigated for their diuretic activity in this study(Table 1). The plants were collected by local traditional

practitioners and were verified for their botanical iden-

tities. Voucher specimens were deposited in the herbar-

* Corresponding author. Tel./fax: +66-43-348386.

E-mail address: [email protected] (B. Sripanidkulchai).1 Present Address: Faculty of Associated Medical Sciences, Chu-

lalongkorn University, Bangkok 10330, Thailand.

0378-8741/01/$ - see front matter 2001 Elsevier Science Ireland Ltd. All rights reserved.

PII: S 0 3 7 8 - 8 7 4 1 ( 0 1 ) 0 0 1 7 3 - 8


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B. Sripanidkulchai et al. /Journal of Ethnopharmacology 75 (2001) 185190186

ium of the Faculty of Pharmaceutical Sciences, Khon

Kaen University. The collected parts were washed and

dried at 5060C until the constant weights were ob-

tained. After pulverizing, each material was passed

through a 20-mm seive and the powder kept in an

air-tight and light-protected container at 4C.

As described by the local traditional practitioners, a

decoction was generally made with plant materials byboiling the samples in hot water until the volume was

decreased to one-third of the initial volume (Sripanid-

kulchai et al., 2000). The laboratory method of extrac-

tion was performed accordingly, with slight

modifications. To be more scientific and reliable, the

powdered samples were soaked in distilled water at

room temperature for 2 h. After boiling, the tempera-

ture was subsequently reduced and kept at 6080C for

an hour. The contents were gauze-filtered, and the

filtrate was centrifuged at low-speed. The supernatant

was collected, lyophilized and stored at 4C. The

yields varied from 2.1 to 16.3% of the initial dried

weight, as summarized in Table 1. The lyophilized

extracts were reconstituted with distilled water prior to

pharmacological studies. In this paper, all doses are

expressed in terms of dried weight of plant samples

used for extraction per body weight of experimental

rats (g/kg).

2.2. Animals

Adult male SpragueDawley rats with a weigh range

of 140150 g were purchased from Mahidol UniversityAnimal Center at Salaya, Thailand. The animals were

then housed in cages of five, at 25C in the animal unit,

Faculty of Medicine, KKU for a minimum of 3 days

prior to pharmacological studies, with free access to

pellet diet and water. The conditions were maintained

on a 12 h light:12 h dark cycle, with an ambient

temperature of 25C. Prior to the start of the experi-

ment all animals were fasted overnight with water,

which was available ad libitum.

2.3. Chemicals

Hydrochlorothiazide, from the Thai Government

Pharmaceutical Organization, was used as a reference

diuretic drug. All other chemicals were obtained for

Sigma Chemical Company.

2.4. Urine 6olume, osmolality, and urinary electrolyteexcretion

The method modified from Kawashima et al. (1985)

was used for the determination of diuresis. All doses

were given orally. Rats, fasted overnight with free

access to drinking water, were given 40 ml/kg of bicar-

bonate saline solution (containing 110 mM NaCl and

30 mM NaHCO3) 30 min prior to using in the follow-

ing experiment.

The animals were divided into 12 groups, 8 animals/

group. Group 1 (control) was given distilled water.

Group 2 was given hydrochlorothiazide, 10 mg/kg dis-

solved in distilled water. Groups 3 12 (test groups)

were given plant extracts at doses equivalent to 5 and

10 g, of plant dried weight before extraction, per kg

body weight of the animals. Each animal was then

placed in an individual metabolic cage and its urine was

collected and the volume measured every hour for 4 h.

Urine osmolality was assessed by the freezing point

depression method (Osmette, Precision System, Inc.).

The content of urinary electrolytes, which included

sodium (Na+), potassium (K+) and chloride (Cl), was

determined by using ion selective electrodes (ElectrolyteAnalyzer system E4A, Beckman).

2.5. Data and statistical analysis

Data are expressed as mean9standard error of

mean (S.E.M.). Statistical comparisons within the same

group were performed with Students t-test for paired

observation. Differences between groups were evalu-

ated, at PB0.01, by using the Students unpaired t-test.

Table 1

Plant names, part used, voucher specimen number, and their yields of extraction

Family Yield (% w/w)VoucherPart usedPlant name

specimen number

ba

Bromeliaceae Root BS 32-016-03 56 16.3A. comosus (Linn.) Merr. (Pineapple, Nana of the Tupi Indians)

Cyperaceae RhizomeC. rotundus Linn. (Nutgrass, Coco grass) BS 32-021-01 23 10.1

C. papaya Linn. (Papaya, Pawpaw, Melon tree) 10.217BS 32-019-01Caricaceae Root

Gramineae RhizomeI. cylindrica (Linn.) Pal. (Cogon grass, Cotton grass, Lalang, Kunai) BS 32-010-03 60 2.1

Averrhoaceae StemA. carambola Linn. (Starfruit, Carambola, Caramba) BS 32-016-04 23 13.4

a Percentage of dried plants compared with fresh weights.b Percentage of dried extracts after lyophilized compared with dried plant weights.


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B. Sripanidkulchai et al. /Journal of Ethnopharmacology 75 (2001) 185190 187

Table 2

Effects of Thai medicinal plants on urine volume in rats

Urine volumeb (4 h in ml/kg body weight)Treatment Diuretic actioncDosea

Distilled water (control) 26.391.62 1.00

43.0992.1310 1.64Hydrochlorothiazide

32.4292.66dA. comosus 1.235

33.9191.90d10 1.29

5C. rotundus 28.0292.29 1.07

26.4390.8510 1.00

28.3193.46C. papaya 1.085

31.9591.40d10 1.21

14.9592.41dI. cylindrica 0.575

15.5892.48d10 0.59

21.3592.25A. carambola 0.815

27.7492.2310 1.05

a mg/kg of hydrochlorothiazide and g of dried plant before extracted per kg.b Each value represents the mean9S.E.M. of eight rats.c Diuretic action= (urinary excretion of treated group (4 h))/(urinary excretion of control group (4 h)).d PB0.01, statistically significant relative to control.

3. Results

3.1. Urine 6olume

As shown in Table 2, Ananas comosus and Carica

papaya were the only two plant extracts that exhibited

diuretic activities. Both extracts increased a 4-h urine

volume when administered at both 5 and 10 g/kg, p.o.

However, the diuretic actions of these two extracts were

less potent than that of hydrochlorothiazide. At 10

g/kg, A. comosus and C. papaya increased the urineoutput volume approximately 79 and 74% of the hy-

drochlorothiazide action, respectively. The extracts ofCyperus rotundus and A6errhoa carambola did not

change the urine volume, whereas the extract of Imper-

ata cylindrica decreased the urine volume at both 5 and

10 g/kg, p.o.

The urinary excretion was compared at the end of

each hour during the 4-h period of studies (Table 3). It

was observed that the control rats urinated more during

the first and the second hours. The extracts from A.

comosus (5 and 10 g/kg, p.o.) and C. papaya (5 g/kg,

p.o.) provided maximum excreted volume during the

second hour, which was a similar profile as that of

hydrochlorothiazide. In contrast, a dose of 10 g/kg, p.o.

of C. papaya gave maximum excretion during the first

hour. I. cylindrica, at both 5 and 10 g/kg, p.o., inhibited

urination of rats throughout the period of studies, while

a maximum inhibition was observed during the first

hour. The other two plant extracts did not increase the

4-h urine volume, but their patterns of urinary excre-

tion in rats were interestingly different from that of the

control. C. rotundus increased the output of urine dur-

ing the second hour, whereas A. carambola delayed theurinary excretion and resulted in less excretion during

the first hour but more excretion during the third hour.

3.2. Urinary osmolality

The urinary osmolatily of the control group appeared

to be constant, regardless of time, whereas the hy-

drochlorothiazide-treated group had a significant and a

time-dependent increase of the urinary osmolality, with

a maximum increment during the second hour (Table

3). Animals treated with all five plant extracts showed

higher urinary osmolality than that of the control

group. With an exception of C. papaya at a dose of 10

g/kg, p.o. and A. carambola at both 5 and 10 g/kg, p.o,

the rest of the extracts caused a maximum urinaryosmolality during the second hour. At 10 g/kg, p.o, C.papaya rendered the highest urinary osmolality during

the first hour. However, the highest urinary osmolality

of A. carambola was observed at 3 h after treatment.

These profiles related to the profiles of the excreted

urine volume.

3.3. Urinary electrolytes

The amount of urinary electrolytes (Na+, Cl and

K+) were measured every hour from the collected

urine, as shown in Table 4. In general, the urine content

patterns of the three electrolytes of the control animals

were similar. Hydrochlorothiazide caused about two

times more urinary Na+ and Cl excretion, during

every hour, than those of the control. A slight increase

of the urinary K+ excretion was also noted with the

hydrochlorothiazide-treated group at the second hour.

Among the five extracts tested, a significant higher

amount of the urinary Na+ excretion was observed

only in the animals treated with C. papaya and A.

carambola. Carica papaya, at 5 and 10 g/kg, p.o. as-sumed the highest urinary Na+ excretion during the

second and the first hours, respectively. This amount


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Table 3

Urine volume and osmolarity after the treatment with the plant extracts over a period of 4 h

Urine volumeb (ml/100 g body weight)Dosea Osmolalityb (mosm)Treatment

hr1 hr2 hr3 hr4 hr1 hr2 hr3 hr4

0.9690.41 0.8390.16 0.4390.10 0.4190.10Control 168930 211937 211938 286971

Hydrochlorothiazide 10 0.5890.13 1.6290.21 0.8390.19 0.7790.16 325972 765990 467938 351960

0.7590.20 1.0990.11 0.9290.11A. comosus 0.4890.115 177948 378946 380943 260940

0.8390.17 1.2390.17 0.6890.13 0.6690.1110 200929 376935 260939 260937

5C. rotundus 0.7890.16 1.2390.10 0.4090.10 0.4090.14 190956 430967 270950 310960

0.6290.12 0.8090.16 0.7190.12 0.5290.06 21791410 269923 311948 228910

0.6490.15 1.2290.15 0.6090.10 0.3890.125 431933C. papaya 670982 359944 359938

10 1.3390.13 0.9590.18 0.6790.14 0.2690.11 594936 392977 337969 247936

5I. cylindrica 0.1590.10 0.6690.15 0.3690.11 0.3290.13 196925 291952 262931 327957

0.3390.14 0.3390.18 0.3990.14 0.5190.1310 227958 3669102 311956 359960

5A. carambola 0.3590.14 0.6590.20 0.8590.09 0.2990.08 383973 544968 619993 263971

0.6590.13 0.7590.19 1.0590.13 0.3390.10 41395710 492931 526960 309938

a mg/kg of hydrochlorothiazide and g of dried plant before extracted per kg.b Each value represents the mean9S.E.M. of eight rats.

appeared as the highest in the urine of both groups

treated with A. carambola during the second and third

hours. The extracts from A. comosus, C. rotundus, and

I. cylindrica produced the reduced amount of urine

sodium, compared with the control.

The amount of urine potassium measured in animals

treated with A. comosus, C. rotundus, and I. Cylindrica,

were slightly higher than that of the control. Through-

out the first 3 h, A. carambola raised the urinary

excretion of potassium, regarding the control and the

hydrochlorothiazide-treated groups. Among these five

extracts, C. papaya resulted in the highest urinary K+

excretion. The maximum amounts were detected during

the second and the first hours at doses of 5 and 10 g/kg,

p.o., respectively. The urinary Cl excretion profiles of

these extracts were similar to those of the sodium. With

respect to the control, extracts from C. papaya and A.

carambola were the only two that increased the urinary

excretion of chloride. However, the urine chloride and

sodium raised by these two extracts was less than that

caused by the hydrochlorothiazide.

3.4. The amount of Na+, K+, and Cl in plant

extracts

Since aqueous extraction was employed in this study,

water soluble salts could be present in the extracts and

subsequently interfere with the urinary excretion. The

content of sodium, potassium, and chloride in the

extracts was, therefore, determined and the results are

shown in Table 5. The total content of salts were in the

order of C. papaya\C. rotundus\I. cylindrica\A.comosus\A. carambola. C. rotundus contained the

highest Na+ content, whereas C. papaya had the

highest content of potassium and chloride. However,the order of these electrolyte contents was not corre-

lated with the diuretic activities of the plant extracts.

4. Discussion

Results from the present study indicate diuretic activ-

ity in the aqueous extracts from the roots of A. comosus

and C. papaya. Both plant extracts gave similar profiles

of urinary electrolyte excretion to that of the hy-

drochlorothiazide, regardless of having a lesser degree

of potency. The extracts from the rhizomes of C.

rotundus and the stem of A. carambola did not exhibit

diuresis, but the extract from I. cylindrica rhizomes

decreased the urine volume under the conditions of our

study. The findings of an antidiuretic effect of I. cylin-

drica is in agreement with the previous studies by

Kanchanapee (1966, 1967). According to those studies,

the antidiuretic activity of I. cylindrica was reported for

rats but not for rabbits. However, these five medicinal

plants were selected from the top of the ethnomedical

list for dysuria, as we aimed to evaluate the relevance

and correlation of plant pharmacological activities

with the practice of traditional herbal medicines.

The plant extracts were singly prepared and tested for

diuretic activity, not in combination as traditionally

applied. However, our procedure for extractpreparation emulated the method described by the tra-

ditional practitioners. These factors might have con-

tributed to the fact that the experimental findings

did not totally agree with the ethnomedical infor-

mation for those plants. Nevertheless, the results paral-

leled the utilization of A. comosus and C. papaya for

dysuria, and also indicate that a more critical review of

I. cylindrica is required before continuing to prescribe

as a diuretic. For C. rotundus and A. carambola,

more studies are also needed, especially on other phar-

macological activities related to the treatment of dy-suria, such as anti-inflammation and antibacterial

activity.


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B. Sripanidkulchai et al. /Journal of Ethnopharmacology 75 (2001) 185190 189

Table4

Totalex

cretionoveraperiodof4hofurinary

electrolytes

K+

(mol)b

Na+

(mol)

b

Treatme

nt

Cl(mol)b

Dosea

hr1

hr2

hr3

hr4

hr1

hr2

hr3

hr4

hr1

hr2

hr3

hr4

799

2.4

919

16

699

16

669

11

339

6.7

339

3.8

1029

27

229

5.7

929

24

289

10

1249

34

1079

42

Control

1739

29

10

1069

27

3259

35

1879

16

1319

22

199

3

619

7.4

329

3.3

179

2.3

1279

33

3529

41

2099

18

Hydrochlorothiazide

439

6.1

849

10

779

11

459

6.8

339

6.5

529

5

749

13

419

5

919

11

219

3.4

A.como

sus

5

279

8

739

9.5

469

11

1009

8

669

11

549

8.5

289

4.5

459

2.5

299

4.5

10

399

15

489

10

939

8.8

729

13

799

11

349

11

1119

12

559

9

639

12

229

5.3

579

7

879

15

259

5.7

C.rotun

dus

259

5.4

709

9

1159

14

469

13

5

789

9

699

6

399

2.6

609

5.5

629

9

339

5.7

339

3.8

369

3.8

369

7.4

149

2.1

10

459

5

649

7.6

1309

13

2479

33

1349

12

1099

17

939

10.6

1249

13

1329

17

619

6.8

C.papaya

459

9.4

1059

16

2309

41

1299

14

5

2169

15

1669

31

1279

25

719

18

1909

9.2

1269

25

1099

20

10

599

20

1699

14

919

19

669

15

619

8

259

5.7

469

10

519

7.6

559

10

279

1.4

429

6.8

829

16

339

3.1

I.cylind

rica

319

3

489

7.6

429

8

389

13

5

279

5.5

839

23

10

579

19

759

14

329

6

539

14

459

8.5

529

10

249

4

689

23

489

21

729

19

1059

18

1719

13

1679

24

699

11

399

19

689

15

659

6.5

769

20

1879

23

659

6.5

A.caram

bola

5

1289

21

1849

15

1099

19

1569

11

10

1469

23

779

9

549

8.9

579

3.3

539

8.5

1069

11

1289

22

1699

16

1749

19

1069

11

a

mg

/

kgofhydrochlorothiazideandgofdrie

dplantbeforeextractedperkg.

b

Eachvaluerepresentsthemean9

S.E.M.o

feightrats.


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Table 5

The content of electrolytes in plant extractsa

K+ ClPlant extract TotalNa+

260141 471A. comosus 872

11753851156C. rotundus 2716

4832C. papaya 1660275 2798

I. cylindrica 1796342 816 638

A. carambola 736165 435 136

a Values expressed in terms of mmol for extracts equivalent to a

dose of 10 g/kg body weight of dried plant.

lowest of the five plants studied. More studies are

needed to clarify the efficacy of this plant.

Acknowledgements

This work was financially supported by the Canadian

International Development Agency (CIDA) and theResearch and Development Institute (RDI), Khon

Kaen University. The authors would like to thank

Deans, Faculty of Medicine, Faculty of Pharmaceutical

Sciences, and Faculty Associated Medical Sciences for

the generous provision of research instruments and

facilities. Our sincere thanks are due to Professor Dr

R.M.E. Richards, Professor Dr Jit Sitteeamorn and

Associate Professor Dr Nantawan Bunyapapatsara for

their critical suggestions and encouragement.

References

Kanchanapee, P., 1966. Phytochemical and pharmacological studies

of I. cylindrica beauv. rhizomes. Bulletin of the Department of

Medical Science 8, 182184.

Kanchanapee, P., 1967. Medicinal plants in Thailand (II). Occurrence

of arundoin and cylindrin in the rhizomes of I. cylindrica and the

examination of the diuretic action of the extracts. Shoyakugaka

Zasshi 21, 6567.

Kawashima, K., Miwa, Y., Kimura, M., 1985. Diuretic action of

paeonol. Planta Medica 50, 187189.

Nilveses, N., Wammanachinda, W., Wanverakul, B., 1988. Pharma-

cological studies of extract from Tribulus terrestris L. Bulletin of

the Department of Medical Science 30, 171183.Nilveses, N., Wammanachinda, W., Wanverakul, B., Pidech, P.,

1989. Diuretic effect of Pluchea indica. Thai Journal of Pharma-

cology 11, 17.

Sripanidkulchai, B., Na-nakorn, S., Wongpanich, V., Tanyakupta, P.,

2000. A behavioral investigation on utilization of medicinal plants

for dysuria at Pon District, Khon Kaen. Khon Kaen University

Research Journal 5 (1), 410.

It was reported by Nilveses et al. (1989) that an

increment of the urine output in rats might result from

a high potassium content in the plant infusion. An

analysis of the urinary osmolality and electrolyte excre-

tion per unit time, together with the plant salt contents,

may help to differentiate the mechanisms by which

these plants act as diuretics. Our results indicated thatthe existing diuretic activity of A. comosus root extract

was intrinsic, and not a result of the salt loading effect.

In fact, this was not the case because its salt content

was the second lowest of the five extracts studied (see

Table 5). The diuretic activity of C. papaya may have

resulted from the high salt content of its extract. How-

ever, this activity appeared to correlate well with the

maximum volume, the highest osmolality, and the

amount of electrolytes excreted during the first hour of

urine collection, at a dose of 10 g/kg, p.o. In contrast to

other extracts, we also observed an interesting effectwith the stem extract of A. carambola. This delayed

urine excretion and resulted in the highest urine volume

and the maximum excretion of potassium during the

third hour of urine collection. Furthermore, the ob-

served diuretic effect of this plant was unlikely to be

associated with its salt content, because this was the

.

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