Antibacterial and antioxidant activities of Vaccinium corymbosum L. leaf extract

ObjectiveTo investigate antibacterial and antioxidant activity of the leaf extract of tropical medicinal herb and food plant Vaccinium corymbosum L. (V. corymbosum).MethodsFree radical scavenging activity on DPPH, ABTS, and nitrites were used to analyse phenoic and flavonoid contents of leaf extract. Other focuses included the determination of antioxidant enzymatic activity (SOD, CAT and GPx), metal chelating activity, reduction power, lipid peroxidation inhibition and the prevention of oxidative DNA damage. Antibacterial activity was determined by using disc diffusion for seven strains of bacteria.ResultsResults found that V. corymbosum leaf extract had significant antibacterial activity. The tested extract displayed the highest activity (about 23.18 mm inhibition zone) against Salmonella typhymurium and the lowest antibacterial activity was observed against Enterococcus faecalis (about 14.08 mm inhibition zone) at 10 mg/ disc. The IC50 values for DPPH, ABTS and radical scavenging activity were 0.120, 0.049 and 1.160 mg/mL, respectively. V. corymbosum leaf extract also showed dose dependent reduction power, lipid peroxidation, DNA damage prevention and significant antioxidant enzymatic activity.ConclusionsThese findings demonstrate that leaf extract of V. corymbosum could be used as an alternative therapy for antibiotic-resistant bacteria and help prevent various free radical related diseases.