IN-VITRO ANTIBACTERIAL ACTIVITY OF LEAF AND ROOT EXTRACTS OF HYPOCHAERIS RADICATA L. (ASTERACEAE) – A MEDICINAL PLANT SPECIES INHABITING THE HIGH HILLS OF NILGIRIS, THE WESTERN GHATS.

摘要

The present study is focused onto investigate the antibacterial activity of different extracts (petroleum ether, chloroform, ethyl acetate, methanol and water) of leaf and root parts of the plant species, Hypochaeris radicata against certain both Gram-positive bacteria (Streptococcus faecalis, S. pyogenes, Enterococcus faecalis, Bacillus subtilis, B. thuringiensis and Staphylococcus aureus) and Gram-negative bacteria (Seratia marcescens, Klebsiella pneumoniae, Proteus vulgaris, P. mirabilis, Salmonella paratyphi, S. parathypi A, S. paratyphi B, Pseudomonas aeruginosa and E. coli.) by following agar disc diffusion method. Methano lic extract displayed broad spectrum of activity against all the test organisms than that of the other extracts. Among the extracts of two parts attempted, the methanolic root extract showed highest antibacterial activity (17.1 ± 0.1). The antibacterial activity of the methanolic extracts of both parts was comparable to that of the standard drug, ampicillin. The minimum inhibitory concentration (MIC) of the methanolic leaf and root extracts was determined by the broth dilution method and was ranging between 200 and 400μg/mL, and 200 and 600μg/mL respectively. The results of this study support the species, H. radicata for its antibacterial agent. The leaf and root extracts can be used to treat various skin and gastrointestinal infections in humans and so has good potential use in the food and cosmetic industries as well.