Research Article STUDY OF PHYTOCHEMICAL AND ANTIMICROBIAL POTENTIAL OF METHANOL AND AQUEOUS EXTRACTS OF AERIAL PARTS OF ELEPHANTOPUS SCABER LINN. P. KAMALAKANNAN, R. KAVITHA, R. ELAMATHI, T. DEEPA, * S. SRIDHAR Department of Botany, Govt. Arts College, Thiruvannamalai 606603, Tamil Nadu, India. Email: sekarsridhar@rediffmail.com Received: 18 September 2011, Revised and Accepted: 26 October 2011 ABSTRACT The present study was carried out to evaluate the phytochemical, antibacterial and antifungal activity of methanol and aqueous extract of Elephantopus scaber Linn. leaf on selected five bacterial pathogens such as Escherichia coli, Staphylococcus aureus, Streptococcus pyogenes, Pseudomonas aeruginosa, Leuconostoc lactis and Salmonella typhi and four fungal strains Aspergillus niger, Aspergillus flavus, Rhizopus indicus and Mucor indicus. For antimicrobial test, well diffusion technique was used and the zone of inhibition of microorganisms was measured in mm. The leaf extract of E. scaber showed not much potential antimicrobial activities against the selected strains and the maximum inhibition zone 28 mm was recorded from 200mg of methanol extract of E. scaber against Streptococcus pyogenes and minimum (18mm) by the above pathogen at 50 mg of methanol extract. The methanolic extract showed the maximum antifungal activity 32mm inhibition zone was recorded from 200mg of extract against Mucor indicus and minimum 14mm by 50 mg of extract against Rhizopus indicus. The phytochemical analysis revealed the presence of Alkaloids, Flavonoids, Saponins, Tannins, Phenols, Proteins and Carbohydrates in varying concentration. Keywords: Phytochemical, Antimicrobial, Elephantopus scaber, Alkaloids, Flavonoids, Saponins INTRODUCTION The increasing failure and side effects of popularity used chemotherapeutic and appearance of multiple drug resistance phenotypes in pathogenic bacteria led to the search of new compounds with antimicrobial activity. Use of herbal products as antimicrobial agents may provide the best alternative to the wide and injudicious use of synthetic antibiotics. The demand on plant based therapeutics is increasing in both developing and developed counties due to growing recognition that they are natural products, non narcotic, easily biodegradable producing minimum environmental hazards, having no adverse side effects and easily available at affordable prices. Therefore researchers are progressively more turning their attention to natural products, looking for new leads to develop better drugs against microbial infections and screening of several medicinal plants for their potential antimicrobial activities (Ghosh et al., 2008). For over several years medicinal plants have served as the models for many clinically proven drugs, and are now being reassessed as antimicrobial agents. Literally thousands of plant species have been tested against hundreds of bacterial strains in vitro and many medicinal plants are active against a wide range of gram- positive and gram-negative bacteria. However very few of these medicinal plant extracts have been tested against resistant bacteria. For a long period of time, plants have been a valuable source of natural products for maintaining human health, especially in the last decade, with more intensive studies for natural therapies. Plants produce a wide array of organic compounds, usually secondary metabolites, which in addition to imparting characteristic odour, pigment and flavour properties, sometimes exhibit antimicrobial action. The extraction, and possible subsequent therapeutic application, of these biologically active phytochemicals is not a recent development, with many plant-derived antimicrobials undergoing clinical trials for human use (Cowan, 1999). The investigation of traditional medicinal plants, function not only to scientifically validate purported properties of traditional medicinal plants, but also in the identification of possible sources of effective drugs. It follows, therefore, that as plant products become more widely exploited as a source of antimicrobial agents, those products in-turn require rigorous characterization, both in identification of active constituents, and in the study of mechanisms by which they exert their antimicrobial activity. However, few studies have included further investigations of the biological action of antimicrobial plant extracts (Ahmad and Beg, 2001). The medicinal plant Elephantopus scaber, a member of the family Asteraceae known for its medicinal properties was also reported to posses antimicrobial activity (Avani and Neeta, 2005). A new terpenoid was isolated from the acetone extract of E. scaber. Biological testing of the compound demonstrated a significant anti-bacterial activity against a few multi drugs –resistant ESBL producing clinical isolates. But the mechanism of the anti- bacterial effect of the compound was not clearly understood to overcome this they tried in nonconventional methods of drug designing by the use of Bioinformatics approaches (Jasmine et al., 2007). MATERIALS AND METHODS Preparation of plant extracts Fresh Plant leaf of Elephantopus scaber was collected from Nolambur village, Villupuram district, Tamil Nadu, India; they were identified with the help of Gamble’s flora. Preparation of powder (Harborne, 1973) The leaves of plants were collected and dried under shade. These dried materials were mechanically powdered sheaved using 80 meshes and stored in an airtight container. These powdered materials were used for further physiochemical, phytochemical and fluorescent analysis Extraction of plant material Various extracts of the study plant was prepared according to the methodology of Indian Pharmacopoeia (Anonymous, 1966). The leaves were dried in shade and the dried leaves were subjected to pulverization to get coarse powder. The coarse powder material was subjected to Soxhlet extraction separately and successively with methanol and distilled water. These extracts were concentrated to dryness in flash evaporator under reduced pressure and controlled temperature (40-50 0 C). Both the extracts were stored in a refrigerator in air tight containers. Both the extracts were analyzed for phytochemical screening of compounds, antimicrobial and pharmacological activity. Phytochemical studies Qualitative phytochemical analyses were done by using the procedures of Kokate et al. (1995). Alkaloids, carbohydrates, tannins, phenols, flavonoids, gums and mucilages, phytosterol, proteins and amino acids, fixed oils, fats, volatile oil and saponins were qualitatively analyzed. International Journal of Current Pharmaceutical Research ISSN- 0975-7066 Vol 4, Issue 1, 2012 A A c c a a d d e e m mi i c c S S c c i i e e n n c c e e s s