Research Letter

A study of the antimicrobial activity of

Finding healing power in is an ancient idea. People with working concentration of 1, 2 and 4 mg/ml of ethyl ac- of all continents and civilizations used plants in one form or etate and petroleum ether extract were used for the study. the other like poultice or decoction. Due to problems like Standard antibiotic ciprofloxacin (Cadila Pharmaceuticals, In- adverse effects, limited lifespan and misuse of traditional dia) at 4 μg/ml concentration was used as positive control. antibiotics, efforts are currently underway to look for products Ethyl acetate extract of the showed growth inhibi- of natural origin. Presently there is an increasing interest in tory effect at 4 mg/ml concentration in all the bacterial iso- the use of plant microbicides because of the necessity of finding lates tested except Klebsiella pneumonia where it showed safer microbicides and the need for preventing environmental ~75% inhibition. Lower concentration of the extract showed degradation. concentration-dependent inhibition effect. At 2 mg/ml 50% Elephantopus scaber Linn () is a small herb, inhibition in all the cultures was seen while at 1mg/ml it was which grows in the wild throughout the hotter parts of .[1] completely ineffective when compared with the positive control The major phytochemical constitutes of the plant are (ciprofloxacin) and control (nutrient medium without antibiotic elephantopin, triterpenes, stigmasterol epifriedelinol and or plant extract) (Table 1). lupeol.[2,3] The plant has been used in the Indian System of Inhibitory effect of the petroleum ether extract with all the Medicine as an analgesic, diuretic, astringent and antiemetic. three concentrations was not found on any of the cultures used The leaves of the plant are used for conditions like bronchitis, for the experiment except Micrococcus luteus where it showed small pox, diarrhea and as a brain tonic.[4] Recently it has been 50% inhibition at 2 mg/ml and complete inhibition at 4 mg/ml shown to possess antiinflammatory and antitumour activity of the concentration (Table 1). in animal models.[2,5] However, no scientific evidence is available The results of the study confirm the antimicrobial potential regarding its antimicrobial activity. An investigation of E. scaber of the ethyl acetate extract of E. scaber. However, further as an antiinfective agent is the objective of our present study. detailed studies are required. The whole plant collected in the flowering stage was macerated overnight with solvents ethyl acetate and petroleum Acknowledgement ether in a 1:5 drug solvent ratio X 3. Exhaustive extraction The authors acknowledge the Industrial Commissionerate and Gujarat Council Of with the solvent was carried out by the cold extraction Science and Technology (GUJCOST) for financial support. procedure. The respective extracts thus obtained were evaporated to dryness, and stored in amber-colored storage K. Avani, S. Neeta vials at 4-50C until used for the experiment. B.V. Patel Pharmaceutical Education & Research Eleven ATCC (American Type Culture Collection) bacterial Development Centre, Thaltej, Ahmedabad-380 054. India. isolates were used in the present study.[6] Agar dilution method[7] Email: [email protected]

Table 1

Effect of ethyl acetate and petroleum ether extract of E. scaber on the growth of bacterial isolates

Bacterial species Control Ciprofloxacin Extract (mg/ml) (ATCC NO.) 124

EA PE EA PE EA PE Bacillus cereus (11778) ++++ - ++++ ++++ ++ ++++ - ++++ Bacillus pumilus (14884) ++++ - ++++ ++++ ++ ++++ - ++++ Bacillus subtilis (6633) ++++ - ++++ ++++ ++ ++++ - ++++ Bordetella bronchiseptica (4617) ++++ - ++++ ++++ ++ ++++ - ++++ Micrococcus luteus (9341) ++++ - ++++ ++++ ++ ++ - - Staphylococcus aureus (29737) ++++ - ++++ ++++ ++ ++++ - ++++ Staphylococcus epidermis(6538) ++++ - ++++ ++++ ++ ++++ - ++++ Escherichia coli (10536) ++++ - ++++ ++++ ++ ++++ - ++++ Klebsiella pneumonia (10031) ++++ - ++++ ++++ ++ ++++ + ++++ Pseudomonas aeruginosa(9027) ++++ - ++++ ++++ ++ ++++ - ++++ Streptococcus faecalis (8043) ++++ - ++++ ++++ ++ ++++ - ++++

Extent of growth: - complete inhibition, + 75% inhibition, ++ 50% inhibition, +++ 25% inhibition, ++++ no inhibition. EA: Ethyl acetate extract, PE: Petroleum ether extract.

126 Indian J Pharmacol | April 2005 | Vol 37 | Issue 2 | 126-128 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 Microsporum 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 dermatophytes. 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 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. Trichophyton rubrum ATCC 28188 250 250 3.0 The American Type Culture Collection (ATCC) strains and 10 250 250 3.0 clinical isolates of Trichophyton rubrum, Trichophyton Trichophyton mentagrophytes, Microsporum gypseum, Microsporum nanum mentagrophytes ATCC 9533 250 250 3.0 and Epidermophyton floccosum 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