Research Letter

References 4. Kritikar KR, Basu BD. In: Indian Medicinal Plants. Vol 2. 2nd ed. Allahabad: Publ. Lalit Mohan Basu; 1991. 1. Anonymous. The Wealth of India, Raw Materials Vol 3. D-E. New Delhi: Coun- 5. Sankar V, Kalirajan R, Sweetlin Vivian Sales F, Raghuraman S. Antiinflammatory cil of Scientific & Industrial Research; 1952. activity of Elephantopus scaber in albino rats. Indian J Pharm Sci 2001;63:523- 2. Rajkapoor B, Jayakar B, Anandan R. Antitumour activity of Elephantopus scaber 5. Linn against Dalton’s Ascitic Lymphoma. Indian J Pharm Sci 2002;64:71-3. 6. Indian Pharmacopoeia. Government of India Ministry of Health and Family 3. Rastogi RP, Mehrotra BN. Compendium of Indian Medicinal plants. Vol 1. New Welfare. Vol 1. Delhi: The controller of Publication; 1996. Delhi: Central Drug Research, Lucknow and National Institute of Science 7. Pelczar MJ. Microbiology. 5th ed. New Delhi: Tata McGraw-Hill Publishing Communication; 1990. Company Limited; 1993.

Antidermatophytic activity of Pistia stratiotes

Dermatophytes belonging to the three genera, Trichophy- ing from 500 μg/ml to 7.8 μg/ml was added in each well with ton, Epidermophyton and affect the keratinous the 1st well having 500 μg/ml concentrations and the 7th well tissue of humans and of other vertebrates, causing superficial having a concentration of 7.8 μg/ml. Negative control con- fungal infections.[1] The present study reports the in vitro tained 200 μl of SDB without extract and inoculum. Miconazole antidermatophytic activity of methanolic leaf extract of Pistia in a concentration range of 96 to 1.5 μg/ml was prepared in stratiotes against a battery of . P. stratiotes SDB, containing fungal inoculum and used as reference stand- (Araceae) is an aquatic, floating stoloniferous herb commonly ard drug (positive control). The final volume in all the wells found in ponds and streams. The leaves are obovate, light green was 200 μl. The contents of each well were mixed on plate in color with many prominent longitudinal veins surrounded shaker at 300 rpm for 20 s and then incubated at 280C for 10 at its base by a membranous sheath which is free-floating and days. MIC was determined by measuring the absorbance at spreads in the water. [2] 450 nm using the ELx 800 universal micro-plate reader (Biotek P. stratiotes leaves are used in traditional medicine for the Instrument Inc.,) and the MFC was determined by plating 5 μl treatment of ringworm infection of the scalp, syphilitic of samples from the microtiter plate into Sabouraud’s Dex- eruptions, skin infections, boils, and wounds. The oil extract trose Agar (SDA) medium and incubating it at 280C for 10 days. of P. stratiotes is used in the treatment of worm infestations, The results indicate that P. stratiotes methanolic extract tuberculosis, asthma, and dysentery, and is applied externally was found to be the most active against the dermatophytes T. to treat skin diseases, inflammation, piles, ulcers, syphilitic rubrum, T. mentagrophytes and E. floccosum with MIC and infections and burns.[3] MFC values of 250 μg/ml, while against M. gypseum and M. The leaves of P. stratiotes used in the present study were nanum, the values were 125 μg/ml (Table 1). The values are collected from the natural habitat in and around Chennai, Tamil Nadu. The Voucher specimen was compared with the Herbarium specimen (No.279) deposited at the Presidency Table 1 College, Chennai. The collected leaves were cleaned, dried in Antifungal activity of the methanolic extract of the Pistia the shade and ground into a fine powder from which 500 g stratiotes leaf were extracted repeatedly with 2 liters of methanol using soxhlet extractor at 50 ºC for 72 h. The extracts were filtered Organism Isolate- Methanolic Miconazole Number extract (μg/ml) (μg/ml) using Whatman filter paper (No.1) and concentrated in vacuum MIC MFC at 40 ºC using a rotary evaporator and the residues obtained were stored in a freezer at -80 ºC until further tests. rubrum ATCC 28188 250 250 3.0 The American Type Culture Collection (ATCC) strains and 10 250 250 3.0 clinical isolates of , Trichophyton Trichophyton mentagrophytes, , Microsporum nanum mentagrophytes ATCC 9533 250 250 3.0 and were obtained from the 12 250 250 3.0 Department of Dermatology, Sri Ramachandra Medical College Microsporum and Research Institute, Porur, Tamil Nadu. The fungal inocu- gypseum ATCC 24102 125 125 3.0 lum was prepared from a 21-day-old culture of dermatophytes 5 125 125 3.0 by scraping with a sterile scalpel and macerating the scrape Microsporum nanum ATCC 11832 125 125 3.0 in 10 ml sterile distilled water. The Minimum Inhibitory Con- 5 125 125 3.0 centration (MIC) and Minimum Fungicidal Concentration (MFC) Epidermophyton floccosum ATCC 52066 250 250 3.0 values of the P. stratiotes extract were determined by 10 250 250 3.0 microplate dilution method,[4] in which 96-well microtiter plates were prepared by dispensing into each well 95 μl of N = 15. The values are same for all the 15 replicate experiments. MIC- Minimum Sabouraud’s Dextrose Broth (SDB) and 5 μl of the fungal Inhibitory Concentration. MFC- Minimum Fungicidal Concentration. μg/ml- Microgram/milliliter. ATCC – American Type Culture Collection. inoculum. A 100 μl of serially diluted P. stratiotes extract rang-

Indian J Pharmacol | April 2005 | Vol 37 | Issue 2 | 126-128 127 Research Letter same for all the 15 replicate experiments. The results show principles responsible for the antifungal activity of P. stratiotes. that the trichophyton and epidermophyton species are more V.G. Premkumar, D. Shyamsundar resistant to the extract and were inhibited at a higher dosage compared to the microsporum species. The MIC that inhibited Department of Biotechnology, Sri Ramachandra Medical the growth of fungi in the SDA medium indicated the fungicidal College and Research Institute, (Deemed University). activity of the extract. The MIC and MFC of the methanolic Extension campus – 24, Vasudeva nagar, Thiruvanmiyur, extract of P. stratiotes were similar and this shows that MIC Chennai -600041. India can be used as an indicator of fungicidal activity as mentioned Email id: [email protected] in earlier studies on the effect of neem on dermatophytes.[5] Miconazole at a concentration of 3 μg/ml inhibited all the References clinical isolates and ATCC strains of tested dermatophytes. Determinations of the MIC of miconazole for all the reference 1. Conant NF, Smith DT, Baker RD, Callaway JL. Mycology of dermatomycoses. strains were performed concomitantly to validate the In: Manual of clinical mycology. Philadelphia: W.B. Saunders Company; 1991. 2. Arber A. The vegetative morphology of Pistia and the Lemnaceae. Proc Roy methodology. The negative control showed no fungal growth. Soc 1991;91:96 -103. Previous reports on the chemical nature of P. stratiotes leaves 3. Kirtikar KR, Basu BD. Indian Medicinal Plants. Mhaskar KS, Blatter E, Caius showed the presence of alkanes, flavonoids and sterols.[6] An- JF, editors. Delhi: Sri Satguru Publications; 2000. tifungal activity of alkanes, flavonoids and sterols has been 4. Sahin F, Karaman I, Gulluce M, Oguttcu H, Sengul M, Aadiguzel A, et al. Evalu- described by earlier workers.[7,8] No data on the antimicrobial ation of antimicrobial activities of Satureja hortensis L. J Ethnopharmacol 2003;87:61-5. activity of P. stratiotes appears to have been published. The 5. Natarajan V, Venugopal PV, Menon T. Effect of (Neem) on results of the present work indicate that P. stratiotes leaves the growth pattern of dermatophytes. Indian J Med Microbiol 2003;21:98-101. possess antifungal properties, which explains the use of this 6. Zennie TM, McClure JW. The flavonoid chemistry of Pistia stratiotes L. and plant in folk medicine for the treatment of various diseases the origin of the lemnaceae. Aquat Bot 1977;3:49-54. whose symptoms might involve fungal infections, and underline 7. Zohri AN, Abdel-Gawad K, Saber S. Antibacterial, antidermatophytic and antitoxigenic activities of onion (Allium cepa L.) oil. Microbiol Res 1995;150:167- the importance of the ethnobotanical approach for the selection 72. of this plant in the discovery of new bioactive compounds. 8. Ibrahim BJ, Salleh M, Yassin M, Chen BC, Lau LC, Lee NS. Antifungal activity Further phytochemical research is needed to identify the active of the essential oils of nine species. Pharm Biol 2003;41:392-7.

FUNDAMENTALS OF EXPERIMENTAL PHARMACOLOGY by M.N. Ghosh

The third edition of Prof. M.N. Ghosh’s book “Fundamentals of Experimental Pharmacology” has been published on 17-03-2005. In this edition the chapters on Receptors have been extensively revised and updated, a few more evaluation techniques have been added, a small introductory chapter on Nitric oxide has been incorporated. A number of new drugs with their dose and concentration have been added in the respective sections that serve as useful reference for the research workers. The analysis of variance (ANOVA) has found a place in the chapter on the Statistical Methods.

The hard bound copy of the book consisting of 268 pages is priced Rs. 250/= and is available with: M/S Hilton & Company, 109, College Street, Kolkata-700 012; Telefax: 91-33-2237-1568; E-mail: [email protected]

J. Rajan Vedasiromoni E-mail: [email protected]

128 Indian J Pharmacol | April 2005 | Vol 37 | Issue 2 | 126-128