Antimicrobial and phytochemical screening of medicinal plants of the United Arab Emirates

Antimicrobial and phytochemical screening of medicinal plants of the United Arab Emirates

ELSEVIER SCIENCE IRELAND Journal of Ethnopharmacoiogy 41 (1994) 201-205 Short communication Antimicrobial and phytochemical screening of medicina...

447KB Sizes 0 Downloads 78 Views

ELSEVIER SCIENCE IRELAND

Journal of Ethnopharmacoiogy

41 (1994) 201-205

Short communication

Antimicrobial

and phytochemical screening of medicinal plants of the United Arab Emirates

M.O.M. Tanira*a, AK. Bashirb, R. Dib”, C.S. Goodwin”, LA. Wasfib, N.R. Bannaa “Department

of

Phurmacoiogy, ‘Department of microbiology, Faculty of Medicine and Health Sciences, ‘Desert and Marine Envir~ffrnent~~ Research Center, Al-Ain, Box 17666, United Arab Emirates (Received 8 April 1993; revision received 11November 1993; accepted 15 November 1993)

Key worcis: Antimicrobial;

Phytochemical;

United

Arab Emirates;

1. Introduction Herbal medicine constitutes a significant part of the heritage of the United Arab Emirates (UAE) (Paul et al., 1992). A herbal center is part of the primary health care service in the capital, Abu Dhabi, and usually receives patients with a variety of chronic diseases such as diabetes mellitus, gastric ulcer, psoriasis, bronchial asthma and rheumatoid arthritis. The flora of the UAE has recently been described in a preliminary work (Western, 1989) and has been shown to be richer than expected for a desert climate. A mountain range in the east side of the country provides an enhancement to the variety of the flora. At present, our team is active in studying the therapeutic potential of the UAE flora. Some reports have already been published (Bashir et al., 1992; Tanira et al.; 1992; Wasfi et al., 1993). Recently, more attention is being paid to the

* Corresponding author.

Medical

plants

possible use of the higher plants as another source of compounds that may possess antibiotic activity. The UAE folk medicine comprises numerous herbal prescriptions for therapeutic purposes such as healing wounds, and treating inflammation due to infection, diarrhea, dysentery, fever and skin ulcers. These folkloric prescriptions contain plants such as Calotropis procera, known locally as Al-Ashkhar and used externally to relieve inflammation, Teueri~~ stoc~~~a~u~ (Al-Ji’dah), recommended by herbalists for gastrointestinal upsets and diabetes, Cistanche tubulosa (Thanoon), used externally for wounds and diarrhea, Nigella sativa (Al-Habbah alsawda), a cure-all, and ~~~~u~~ elegans (Al-Rimth), used externally for infected wounds. In the course of our investigation to evaluate the therapeutic potential of the UAE flora, we undertook this study to test the antimicrobial activity of these plants. The hypothesis tested was to ascertain whether the antimicrobial action was responsible, at least in part, for the effectiveness of these recipes. We have also included in our study some commonly growing local herbs.

0378-8741/~/~07.~ 0 1994 Eisevier Science Ireland Ltd. All rights reserved. S.SDf 0378-8741(93)01086-2

202

M.O.M.

2. Materials and methods

all tested species are kept at the National Herbarium. The plants were cleaned, dried in the shade at room temperature, powdered, and extracted with 95% ethanol in a Soxhlet apparatus. Underground parts, seeds and fruits were first defatted with petroleum ether and these extracts were also tested for activity. A chloroform extract was prepared from Hammada elegans. The liquid extracts were evaporated under vacuum and the residues weighed and tested for antimicrobial

2.1. Plant materials Plants were collected from the locally growing flora of the United Arab Emirates, mostly around the Al Ain area. They were botanically authenticated by the taxonomist at the UAE National Herbarium. Albizzia lebbeck and Zphiona aucheri were sent for identification to the Royal Botanic Gardens, Edinburgh, UK. Voucher specimens of

Tanira et al. /J. Ethnopharmacol.

41 (1994) 201-205

Table 1 Antimicrobial assay results Species

(FAMILY)

Parta

Solventb

Yeast

Gram-positive

Gram-negative

S.a.c

.s.f:

E.cl.

E.co.

K.p.

P.a.

P. Y.

Sm.

Ca. Arnebia hispidissima

AP

A

0

0

0

0

2 mg/ml

0

0

0

0

L

A

0

0

0

0

0

0

0

0

2 mg/ml

F

A

0

0

0

0

2 mg/ml

0

0

0

0

C

P

0

0

0

0

0

3 mg/ml 0

3 mg/ml

2 mgiml

A P

3 mg/ml 0

0 0

0

0

0

0

0 0

0 0

3 mgml 0

0 0

0

R AP

P

0

0

0

0

0

0

0

0

3 mgml

C A

0 3 mg/ml

0 0

0

0

AP

0

0

2 mg/ml 2 mg/ml

0 0

0 0

0 0

0 3 mg/ml

FI

A

0

0

0

0

0

0

0

0

3 mgml

F

0 0 0

0 0 0

0

0

0

0

0

0

0

0

L

P A A

0

0

3 mg/ml 2 mg/ml

0 0

0 0

0 0

3 mgiml 0 0

AP

A

2 mg/ml

0

0

0

3 mg/ml 0

0

0

0

(Lehm.) DC. (BORAGINACEAE)

Calotropis procera

(Ait.) Ait. f. (ASCLEPIADACEAE)

Chrozophora oblongifoliu (Del.)

Juss. ex. Spreng. (EUPHORBIACFAE)

Cistanche tubulosa

(Schenk) Wight (OROBANCHACEAE)

Cyperus rotundus L.

I mg/ml

(CYPERACEAE)

Hammodo elegans

(Bge.) Potsch. (CHENOPO~~DIACEAE] I

Heliotropium kotschyi (Bge.)

Gurke (BORAGINA~EAE)

Ochradenus arabicus

(Chaudhary, Hillcoat & Miller) (RESEDA~EAE)

Salvia aegyptiaca L. (LABIATAE)

Teucrium stocksianum Boiss. (LABIATAE)

aPart used AP, aerial parts; C, corm; F, fruits; FI, flowers; L, leaves; R, rhisomes; S, seeds. bSolvent: A, 95% ethanol; C, chloroform; P, petroleum ether. CMicroorganisms: S.a., Staphylococcu aureus; S.$, Streptococcus faecalis; E.cl., Enierobacter cloacae; E.co.. Escherichia coli; K.p., Klebsiella pneumoniae; P.a., Pseudomonas aeruginosa; P. v., Proteus vulgaris; S.m., Serratia marcescens; C.a., Candida albicans. 0, no growth inibition.

M.0.M. Taniraet al. /J. Ethnopharmacol. 41 (1994) 201-205

203

activity. For phytochemical analysis, the powdered plant material (50 g) was extracted with petroleum ether (b.p. 60-80°C) for 24 h, using a Soxhlet apparatus. The defatted powdered plant material was air-dried and divided into 5 batches (10 g each). Each batch was then separately extracted with a suitable solvent for the various identification tests.

Hinton agar. Control agar plates were always run in parallel and treated similarly except for the presence of the plant extract. After inoculation, the agar plates were allowed to stand undisturbed until the inoculum spots were completely absorbed, then incubated at 35°C for 16-20 h. MICs rep-

2.2. Phytochemical screening methods The defatted powdered material was extracted with ethanol and tested for alkaloids as described by Rizk (1982) and Bashir (1980). The ethanolic extract was also tested for free and glycosidic bound anthraquinones as described by El-Tawil (1983), for flavonoids using 1% aluminium chloride solution in methanol, concentrated HCl and magnesium turnings and potassium hydroxide solution (Kapoor et al., 1969) and for tannins using 1% gelatin solution and quinine sulphate solution with FeCl, (Segelman and Farnsworth, 1969; Segelman et al., 1969). The defatted material was tested for sterols and/or terpenes using Liebermann-Burchard and Salkowski’s reactions (Wall et al., 1954; Ahmed et al., 1972) and for cardiac glycosides using the Keller-Kiliani and Legal tests (Bashir, 1980). Saponins were identified by subjecting the aqueous extract to froth and haemolysis tests (El-Tawil, 1983; Rizk, 1982).

Table 2 Plants showing no activity concentrations 5 3 mg/ml

2.3. Microorganisms The following strains of bacteria and a yeast were used: Staphylococcus aureus (ATCC 25923), Streptococcus faecalis (ATCC 19433) Klebsiella pneumoniae (ATCC 13883), Escherichia coli (ATCC 25922) Proteus vulgaris (ATCC 13315), Pseudomonas aeruginosa (ATCC 27853), Enterobatter cloacae (ATCC 23355), Serratia marcescens (ATCC 8100) and Candida albicans (ATCC 14053). 2.4. Determination of the minimal inhibitory concentration (MIC)

To test for antimicrobial activity, the agar dilution method was used. The plant extract was dissolved in small amounts of the appropriate solvent (distilled water, dimethylsulfoxide or dimethylformamide) and then mixed with Mueller-

against

tested microorganisms

Species (FAMILY)

Part”

Albizzia lebbeck (L.) Benth.

L

at

Solvent b

(LEGUMIN~SEAE)

Avicennia marina (Forssk.) Vierh.

AP

(VERBENA~EAE)

Caralluma arabica N.E.

AP

P. A

L

P

AP

P, A

AP

A

R

A

WP

P, A

L

A

AP

A

S

P, A

L

P

F

P, A

AP

A

Brown (A~~LEPIA~A~EAE)

Chrozophora oblongifolia (Del.) Just. ex. Spreng. (EUPHORBIACEAE)

Cleome rupicola Vicary (~APPARA~EAE)

Crotalaria aegyptiaca Benth. (LEGUMINOSEAE)

Cyperus rotundus L. (CYPERACEAE)

Haplophyllum tuberculatum (Forssk.) A. Juss. (R~TACEAE)

Iphiona aucheri (Boiss) A.A. Anderb. (~OMPOSITAE)

Leptadenia pyrotechnica (Forssk.) Decne. (ASCLE~IAOA~EAE)

Nigella saliva L. (RANUNCULACEAE)

Salvia aegyptiaca L. (LABIATAE)

Schweinfirthia papilionacea (Burm.f.) Boiss. (SCR~PHULARIACE,~E)

Zilla spinosa (L.) Prantl (cRucI~~ik+E)

Tested microorganisms: Staphylococcus aureus, Streptococcus faecalis, Enterobacter cloacae, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus vulgaris, Serratia marcescens, Candida albicans. “Part used AP, aerial parts: C, corm; F. fruits: Fi. flowers; L. leaves; R, rhizomes; S, seeds. bSolvent: A, 95% ethanol; C, chloroform; P. petroleum ether.

204

M.O. M. Tanira et al. /.3. Ethnopharmacol. 41 (1994) 201-205

resent the lowest concentration of plant extract at which complete inhibition occurs. Four dose levels were successively tested: 3,2, 1 and 0.5 mg of plant extra&ml.

activity, compared with six of 16 plants not used medicinally. The results are summarized in Tables 1 and 2.

3. Results 3.i. Antimi~robiai testing Of the 21 species studied, ten showed antimicrobial activity. Five of these were active against C. albicans and seven inhibited the growth of K. pneumoniae. Three species (Cistanche tubulosa, ~el~otropium kotschyi and Teucrium sto~ksianum~ inhibited both Gram-positive and some Gramnegative organisms. Four of the five species used in folk herbal prescriptions showed antimicrobial

Table 3 Results of phytochemical

analyses

Plant species

Part”

Terpenesb and/or sterols

A fbizzia Iebbeek Arnebia hispidissima Avicennia marina Caloiropis procera Caralluma arabica Chrozophora #bi~ngi~olia Cistanche tubulo.~a Cieome rupicoia Crotalaria aegyptiaca Cyperus rotundus Hammada elegans Ha~~~ph~~l~~

L AP AP L AP L

++ + ++ f + +

tuber~ulatum Heliotropium kotschyi Iphiona aucheri Leptadenia pyrotechnica Nigella sativa Ochradenus arabicus Salvia aegytiaca Sch~~e~nfurth~a papilionacea Teurrium stocksianum Zilla spinosa

C AP AP R AP WP

+

++ f ++ ++

AP S F L F AP AP

+ +

Saponins

++t ++ ++ +

+

+ + ++ + + + ++

AP L

Alkaloids

3.2. Phytochemical analyses All tested plants showed positive reaction to terpenes and/or sterols, and all but Nigefla sativa reacted positively to the presence of tannins. All but Cyperus rotundus and ~ara~iuma arabica indicated the presence of saponins, and most (in variable degrees) showed positive reaction to flavonoids and alkaloids, whereas none contained anthraquinones. Only Calotropis procera showed positive reaction to cardiac glycosides; this last observation has been previously reported by another worker (El-Tawil, 1983). The results are summarized in Table 3.

++ + + +

++ + + + + + + ++ + + + ++ + +

“Parts used: AP, aerial parts; C, corm; F, fruits; L, leaves; R, rhizomes; b+++, appreciable amount; ++, moderate amount; +, trace amount; f,

Anthroquinones

-

Flavonoids

Cardiac glycosides

Tannins

+ + + + f +

++

-t + ++ +

-

+

-

+ ++ + + + ++

-

-

++ f + ++

_ -

_ -

f + +

-

-

f -

-

-b-T-+ -

-

S, seeds; WP, whole plant. doubtful; -, complete absence.

-

-

+ + +++ f + if ++ ++

M. O.M. Tan&a et 01. /J. Ethnopharmacol.

41 (1994) 201-205

4. Discussion

205

paris species: lipids and flavonoids. Planfa Medica 21,

156-160.

The observed antimicrobial activity does not appear to be confined to any particular family nor to be restricted to a specific microorganism. However, the most susceptible species were found to be K. pneumoniae (7 extracts inhibited its growth) and C. aibicans (7 extracts inhibited its growth). On the other hand, the growth of Strep. fae~aIis~ Entero. cloacae and E. coli was not inhibited by any of the tested plant extracts. Staph. aureus growth was inhibited by 3 plant extracts. The MICs of the effective plants extracts were mostly in the range 2-3 mg/ml. Only Cyperus rotundus inhibited the growth of C. albicans at a 1 mg/ml concentration. Two observations are worthy of emphasis. First, P. aeruginosa growth was inhibited by Cistanche tubulosa corm extract. This is one of the more resistant microorganisms to commonly used antibiotics in clinical practice. Secondly, K. pneumoniae growth was inhibited by a surprisingly large number of extracts (7 plants). Such observations deserve further study in order to isolate pure compounds that may be responsible for this action. The results obtained showed that the UAE flora is, potentially, a rich source of antimicrobial agents. It is evident that the likelihood of finding antimicrobial activity was higher for species used in traditional herbal therapies than in other indigenous species, which justifies the folkloric use of these plants at least in some of the abovementioned pathological conditions. 5. Acknowledgment This work was supported by a grant from the Ministry of Health, Abu Dhabi. 6. References Ahmed, Z.F., Rizk, A.M., Hammouda, F.M. and Seif El-Nasr, M.M. (1972) Phyt~hemicat investigation of Egyptian Cap

Bashir, A.K. (1980) Pharmacognostic studies on certain Sudanese medicinal plants Randia nilotica and Grewia villosa. Ph.D. Thesis, University of Wales, Card%. Bashir, A.K., Hassan, ES., Amiri, M.H., Abdalla, A.A. and Wasfi, LA. (1992) Antimicrobial activity of certain plants used in the folk-medicine in United Arab Emirates. Fitoterapia 63, 371-375.

El-Tawil, B.A.H. (1983) Chemical constituents of indigenous piants used in native medicine of Saudi Arabia. II. Arab Cuff Journal of Scientific Research t , 395-418. Kapoor, L.D., Singh, A., Kapoor, S.L. and Srivastava, S.N. (1969) Survey of Indian medicinal plants for saponins, alkaloids and flavonoids I. Lloydia 32, 297-302. Paul, S., Tanira, M.O.M. and Banna, N.R. (1992) The role of medicinal ptants in the health-care system of the United Arab Emirates: past, present and future. In: Firsr World Congress on Medicinal and Aromatic Plants for Human Welfare, Maastricht, The Netherlandr (Abstracts). p. 16.

Rizk, A.M. (1982) Constituents of plants growing in Qatar I. A chemical survey of sixty plants. Fitoterapiu 53, 35-44. Segelman, A.B. and Farnsworth, N.R. (1969) Biological and phyt~hemi~ evaluation of plants IV. A new rapid procedure for the simultaneous dete~ination of saponins and tannins. Lloydia 32, 59-61. Segelman, A.B., Farnsworth, N.R. and Quimby, M.D. (1969) Biological and phytochemical evaluation of plants III. False-negative saponins test results induced by the presence of tannins. Lioydia 32, 52-55. Tanira, M.O.M., Was& LA., Bashir, AK., Amiri, M.H. and Banna, N. (1992) Evaluation of the antiin~a~ato~ activity of some plants used in folk medicine in the United Arab Emirates. In: First World Congress on Medicinal and Aromatic Plants for Human Welfare. Netherlandr (Abstracts). p. 12.

Maastricht,

The

Wall, M.E., Kreider, M.M., Krewson, CF., Eddy, CR., Williams, J.J., Core& D.S. and Gentry, H.S. (1954) Survey of plants for steroidal sapogenins and other constituents. Journal ofthe American Pharmaceutical tific Edition 43, 1-7.

Association,

Scien-

Wasfi, I.A., Amiri, M.H., Bashir, A.K. and Abdalla, A.A. (1993) The effect of Rhazya stricta on glucose homeostasis in normal and streptozotocin diabetic rats. Journal of Ethnop~rmaeology (in press). Western,A.R. (1989) The Flora of the United Arab Emirates: An Introduction. United Arab Emirates University Press, Al Ain.