Abstract

The antibacterial potentials of Cassia occidentalis leaf extracts were investigated against eleven Gram-positive and four Gram-negative bacterial isolates. The n-hexane and dichloromethane fractions of the plant extract exhibited appreciable antibacterial action against nine out of the fifteen bacterial isolates tested at a concentration of 20 mg/ml. The zones of inhibition exhibited by n-hexane fraction ranged between 16 and 27 mm while that of dichloromethane fraction ranged between 15 and 28 mm. On the other hand, the zones of inhibition observed for the standard antibiotic, streptomycin ranged between 13 and 30 mm. The minimum inhibitory concentrations exhibited by n-hexane and dichloromethane fractions against the susceptible test isolates ranged between 0.157 and 1.25 mg/ml, respectively. Overall, the two fractions compared favourably with the standard antibiotic, streptomycin used in this study. The phytochemical analysis of the extract revealed the presence of tannins, Saponins, anthraquinones and flavonoids.

Key words: Cassia occidentalis, antibacterial activity, phytochemical compounds, National Collection for Industrial Bacteria (NCIB), locally isolated organism (LIO).