Abstract
Plants produce a wide variety of phytochemical constituents, which are secondary metabolites and are used either directly or indirectly in the pharmaceutical industry. 'For centuries, man has effectively used various components of plants or their extracts for the treatment of many diseases, including bacterial infections. In the present study methanol, chloroform and aqueous extracts of Cassia auriculata leaf were subjected for antimicrobial activity by well-diffusion method against six bacterial strains namely Bacillus cereus, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Proteus mirabilis. The results revealed that the methanol and chloroform extracts exhibited strong inhibitory activity against all the tested organisms (zone of inhibition of 12-20 mm), except Pseudomonas aeruginosa (zone of inhibition 10 mm or nil). The aqueous extracts showed moderate activity by 'Zone of inhibition ≤12 or nil). The extracts were screened for their phytochemical constituents by standard protocols' and were shown to contain carbohydrates, proteins, alkaloids, flavonoids, steroids, saponins and tannins. The antibacterial activity of these extracts is possibly linked to the presence of flavonoids, steroid, saponins and/or tannins. Further studies are needed to determine the precise active principles from Cassia auriculata.