Journal of Medicinal Plants Research Vol. 6(26), pp. 4343-4346,11 July, 2012 Available online at http://www.academicjournals.org/JMPR DOI: 10.5897/JMPR12.551 ISSN 1996-0875 ©2012 Academic Journals Full Length Research Paper Screening of various extracts of Gymnema sylvestre (Retz.) R.Br. ex Schult. for antimicrobial activity Sudhanshu 1 , Sandhya Mittal 1 , Nidhi Rao 1 and Ekta Menghani 2 * 1 Suresh Gyan Vihar University, Jaipur, India. 2 Mahatma Gandhi Institute of Applied Sciences, JECRC Campus, Jaipur-22, India. Accepted 17 April, 2012 Rising appearance of resistance to the presently existing antibiotics has necessitated sustained search for new antimicrobial compounds. The present study was designed to confirm ethno-medicinal assert of Gymnema sylvestre possessing antimicrobial activity that could be a superior alternative for synthetic antimicrobial agents, if proved to be successful enough. For this, the antimicrobial properties of G. sylvestre were tested against seven bacteria (Shigella flexneri, Staphylococcus aureus, Salmonella typhi, Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus vulgaris, and Enterobacter aerogenes) and three fungi (Aspergillus niger, Candida albicans, and Trichophyton rubrum) by using different solvents like petroleum ether, chloroform, benzene, ethyl acetate, ethanol and distilled water. The result showed that all the solvent extracts exhibited considerable activity against the tested microorganisms. The antibacterial activity increased with the increasing concentration of the extract. Petroleum ether solvent extract of G. sytvestre is less active against all test microorganisms than five other solvent extracts, and distilled water extract is highly active against all test microorganisms. All solvent extracts at lower concentration of 50 mg/ 20 disc showed very smaller amount of activity against all test microorganisms. Key words: Gymnema sylvestre, antibacterial activity, bacterial infections, medicinal plant. INTRODUCTION Plants have for eternity played a significant role for mankind mainly as food and medicine. In the last few decades, there has been an exponential increase in the field of herbal medicine for the treatment for chronic diseases. Various extracts from customary medicinal plants with folklore character have been examined (Awadh et al., 2001; Sinha and Biswas, 2010) to identify the basis of therapeutic drugs, but there is still a vital need to screen novel substances that are bioactive towards pathogens with high resistance (Cragg et al., 1997). Gymnema sylvestre R.Br. (Asclepiadaceae) is a large, branched woody climber which grows mostly in the *Corresponding author. E-mail: ektamenghani@yahoo.com. tropical forest of central and south India and some parts of Africa (Anonymous, 1997). It is known as Madhunashini, Gurmarbooti, and Meshashringi. It is used in the treatment of several diseases such as diabetes, corneal opacity, heart diseases, leucorrhoea, urinary infections, liver diseases, snake bite, stomach complaints and dental caries (Hiji Yasutake, 1990). Its roots are used as astringent, emetic, expectorant, refrigerant, stomachic and tonic (Uniyal, 1993; Selvanayagam et al., 1995). In the present study, the selection of this plant for estimate was based on its traditional usages. Although very small number of works have been done on the antimicrobial activity of this endangered medicinal plant (Satdive et al., 2003; Devi and Ramasubramaniaraja, 2010), it needs further study for verification of its activity against disease- causing microorganisms. This paper describes the evaluation of the antimcrobial potency of G. sylvestre