Abstract
Antibiotic resistance is a problem that continues to challenge the healthcare sector in a large part of the world. It is very important to control that problem, so the discovery of new active compounds and antibiotic has focused on screening bacteria for new growth inhibitory compounds. This study aimed to investigate the antibacterial, antioxidant potential and phytochemical composition of extracts of Moringa oleifera Lam. leaves in methanol, ethyl acetate and hexane against clinically resistant bacterial isolates. A total of 8 bacterial isolates were selected to analyze the antibacterial and antioxidant potential of various Moringa oleifera leaf extracts. Antimicrobial susceptibility test was performed by Kirby-Bauer disc diffusion technique and MIC and MBC values were also recorded. Antioxidant potential was determined based on the free radical scavenging activity of 2, 2- diphenyl-1-picrylhydrazyl (DPPH) assay. Finally, qualitative and quantitative analyses of phytochemical constituents of Moringa oleifera leaf extracts were performed by HPLC. Result showed that ethyl acetate extract demonstrated higher antibacterial activity against Bacillus subtilus with zone of inhibition 28 +/- 8.2 mm, followed by Streptococcus viridans (21.67 +/- 5.86 mm). These extracts were not active against E. coli, Klebsiella pneumonia and Salmonella group B. Hexane extract showed antibacterial activity against all tested bacteria. The extracts showed strong antioxidant activity with 50% efficient concentration (EC50) values of 117.94 and 150.96 mu g/ml for the methanol and ethyl acetate extracts respectively. The highest phenolic content was observed in methanolic leaf extract with 140.19 +/- 0.0.71 (mg GAE/g) while flavonoid was found 98.67 +/- 2.10 (mg QE/g) respectively. In addition, different phenolic and flavonoid compounds were also determined individually. This study concludes that Moringa oleifera Lam. leaf extracts have significant antimicrobial and antioxidant properties which authenticate its potential as cure against a wide variety of infectious bacterial diseases.