Evaluation of Antibacterial and Antioxidant Activity of Leaves, Fruit and Bark of Kigelia Africana

In vitro antibacterial activity of extracts was tested against six bacterial strains viz. Staphylococcus aureus, Proteus vulgaris, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Citrobacter amalonaticus by agar-disc diffusion method. Ethanol and n-hexane were used as negative control and oxytetracycline was used as a positive control. Ethanolic and aqueous extracts of bark and leaves of Kigelia africana showed remarkable activity against various bacterial strains as compared to n-hexane. S. aureus and E. coli were proved as highly sensitive strains while K. pneumonia was the resistant strain as the extracts formed no inhibition zone against it. The percentage of antioxidant activity of different parts of Kigelia was assessed by DPPH (1, 1-diphenyl-2-picrylhydrazyl) free radical assay. Quercetin was used as a standard antioxidant which showed 93.6 percent inhibition. Kigelia bark extract showed good antioxidant activity i.e., 67.33 percent inhibition, fruit extract possess moderate antioxidant activity i.e., 62.66 percent inhibition while leaves showed the poor antioxidant activity i.e., 59.66 percent DPPH inhibition respectively. Overall, the comparative analysis revealed that bark extract exhibited the most remarkable antibacterial as well as antioxidant activity as compared to leaves and fruit extracts. (author)