Comparative evaluation of Ziziphus mauritiana leaf extracts for phenolic content, antioxidant and antibacterial activities

The solvent extracts of Ziziphus mauritiana leaves were evaluated for phenolic and flavonoid content and antioxidant and antibacterial activities. Ethanol extract had the highest antioxidant capacity in all the tested assay models except for superoxide scavenging assay; ethyl acetate extract had the highest superoxide scavenging activity. The reducing power and cupric antioxidant capacity increased with increasing amounts of extract in all cases. All the extracts exhibited broad spectrum antibacterial activity with zone of inhibition ranging from 7.33 ± 1.53 mm to 22.33 ± 0.58 mm against tested isolates. Ethyl acetate extract had the highest antibacterial activity against Vibrio parahemolyticus with 22.33 ± 0.58 mm zone of inhibition and the lowest MIC and MBC values of 2.5 and 4.0 mg mL−1, respectively. The ethanol leaf extracts had the highest total phenolics (182.93 ± 6.94 mg GAE g−1 extract) that was highly correlated with r values ranging from 0.901–0.991 for phenolic and 0.960–0.989 for flavonoid contents, respectively.