Antimicrobial activity of Berkheya bergiana leaves extracts
The leaves of Berkheya bergiana Soderberg (Asteraceae) were screened for phytochemical composition and antimicrobial potential. Phytochemical screening of the crude methanol extract showed the presence of various secondary metabolites. In vitro antimicrobial activities of the extracts obtained from six solvents were carried out against 28 bacterial strains using traditional methods. Chloroform extract exhibited the highest broad spectrum antibacterial activity against the tested bacteria and decreased in the order chloroform > ethyl acetate > butanol > hexane > aqueous extract at a concentration of 5.0 mg mL-1 for bacteria. The minimum inhibitory concentration (MIC) exhibited by EtOAc, CHCl3 and HEX extracts against the bacterial strains range between 0.07 and 2.5 mg mL-1, while that of BuOH and aqueous extracts ranged between 0.07 and 5.0 mg mL-1. The antibacterial activities of the plant were compared with standard (neomycin, ampicilin and tetracycline) antibiotics at the same concentration. The leaves extracts showed antibacterial potential, inhibiting the growth of some of the tested bacterial more than the standard drugs. The results obtained appeared to confirm the antibacterial potential of the plant investigated.
Key words: Berkheya bergiana, Asteraceae, antimicrobial activity, screening.