Antimicrobial Activity Of Methanolic Extract And Oil Of Saussurea Costus Roots

The methanolic extract (SCE) as well as the essential oil (SCO) prepared from the roots of Saussurea costus (Falc.) Lipschitz, were tested for their antimicrobial activity against 14 G+ve and G-ve bacteria implicated in gastro-intestinal (GI), respiratory tract (RT) and urinary tract infections (UTI). Their effects were also compared to standard concentration of antibiotic erythromycin. The in vitro antibacterial activity was assessed qualitatively (by disc diffusion method) and quantitatively (by microdilution method). SCO exhibited better antimicrobial activities as compared with SCE. The GI pathogens viz. Shigella flexneri and Salmonella typhimurium were the strains most susceptible to the oil (strong inhibition zones 25-28 mm). SCO showed also had minimal inhibitory concentrations (MIC) ranging from 1.09-8.75 il/ml on 10 of the 14 pathogens tested. The overall results provide promising baseline information for the potential use of the oil from the roots of S. costus in the treatment of bacterial infections.