Abstract

EVALUATION OF ANTIBACTERIAL AND ANTIOXIDANT ACTIVITIES OF THE LEAF AND BARK EXTRACTS OF AZADIRACHTA INDICA A. JUSS

*L. Joji Reddy¹, Spandana Gopu¹, Beena Jose², Reshma Devi Jalli¹

Abstract

The antibacterial and DPPH radical scavenging activities of the leaf and bark extracts of Azadirachta indica A. Juss were investigated. The antibacterial potential of the petroleum ether, chloroform, ethyl acetate and methanol extracts of the leaves and bark of Azadirachta indica were studied against human pathogenic bacteria viz. Bacillus cereus, Enterobacter faecalis, Salmonella paratyphi, Staphylococcus aureus, Escherichia coli, Proteus vulgaris, Klebsiella pneumoniae, Pseudomonas aeruginosa and Serratia marcescens by �agar well diffusion� method. Ethyl acetate, chloroform and methanol extracts of Azadirachta indica bark and leaves exhibited pronounced activity against Gram-positive and Gram-negative bacteria and their activity is quite comparable with the standard antibiotics such as tobramycin, gentamicin sulphate, ofloxacin and ciprofloxacin screened under similar conditions. Among the leaf and bark extracts of A. indica studied, methanol and ethyl acetate extracts of both leaf and bark showed potent scavenging activity on 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical. The remarkable antibacterial and antioxidant activity exhibited by the plant extracts can be attributed to the synergic effect of the active compounds present in it. The results obtained showed that the leaf and bark methanol and ethyl acetate extracts of A. indica can be considered as good sources of natural antioxidants and antimicrobial compounds and can be incorporated into the drug formulations.

Keywords: Azadirachta indica, antibacterial activity, agar well diffusion method, antioxidant activity, DPPH radical scavenging activity, drug formulations