Evaluation of Antibacterial and Antioxidant potential of Melia. Azedarach linn. and Psidium guajava linn. Leaf extracts

Abstract

The present study is intended to evaluate and analyze in-vitro antibacterial and antioxidative activities of leaf extracts of Melia azedarach Linn (M. azedarach L.) and Psidium guajava Linn (P. guajava L.). In-vitro antibacterial activity was measured using agar well diffusion assay against Pseudomonas aeruginosa and Staphylococcus aureus strains. In-vitro antioxidant activity was estimated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging method. Among both plants high minimum inhibitory concentration values are observed with P. guajava L. ethanol extract at 47.6µg/ml for S. aureus and 43.7µg/ml for P. aeruginosa, respectively. The results revealed that 20µg/ml ethanol extracts of P. guajava L. exhibited the highest radical % scavenging activity (76.24%) succeeded by methanol extracts (72.78%), respectively indicating they are effective solvents to extract phenolic compounds. We demonstrated that for both bacterial strains, ethanol followed by methanol extracts showed significant antibacterial activity in P. guajava L.in dose dependent manner indicating the presence of high flavonoids, tannins, and steroids. Our results revealed that both plants are vital reservoirs of phytochemicals with both antibacterial and antioxidant capacities.