Antibacterial activities of ethanol leaf and bark extracts of Terminalia avicennioides against methicillin resistant Staphyloccocus aureus

Abstract

The study was undertaken with the aim to determine the Antibacterial activities of ethanol leaf and bark extracts of Terminalia avicennioides against Methicillin resistant Staphyloccocus aureus (MRSA). Air-dried leaves and barks of Terminalia avicennioides, were powdered and each extracted with 70% ethanol by cold maceration method. Each extract was screened for the presence of some secondary metabolites using qualitative methods. MRSA clinical isolates from infected wounds of patients were reconfirmed using standard microbiological methods. The antibacterial activities of extracts against bacteria were determined by agar well diffusion and broth dilution methods. The results of phytochemical screening of extracts revealed the presence of carbohydrates, alkaloids, tannins, flavonoids, saponins, steroids, triterpens, glycosides and phenols. All the extracts exhibited significant inhibitory effects (P < 0.05) against isolates of bacteria at varied concentrations of 100, 50, 25 and 12.5 and 6.25mg/mL and the activity of each extract was found to be concentration dependent. The mean zone of inhibition of the leaf extract against bacteria ranged between 12.52 ± 1.86 mm -17.12 ± 1.89 mm while the mean zone of inhibition of the bark extract ranged between 10.26 ± 1.37 mm - 14.45 ± 1.47 mm. The leaf extract was more effective with MIC and MBC of 6.25mg/mL and 25mg/mL. The results of this study show that the leaf and bark extracts of T. avicennioides contain compounds with antibacterial activities against MRSA which provide basis for further studies to isolate, identify and standardize the active compounds for drug development