Authors : B.M. Olabinri, M.T. Olaleye, O.O. Bello, L.O. Ehigie and P.F. Olabinri
Abstract: The influence of concentration on hydroxyl radical scavenging and antioxidant activities of polyphenol extracts of Mango and Pawpaw leaves were assessed in vitro. The polyphenol extract from Mango leaves failed to scavenge hydroxyl radical at all the concentrations (50-250 μg mL-1) while Pawpaw leaves failed to scavenge hydroxyl radical at three different concentrations out of five concentrations investigated (50-250 μg mL-1). The polyphenol extract from Pawpaw leaves was a poor scavenger of hydroxyl radical in vitro (4.2% maximum scavenging activity). The polyphenol extracts of Mango and Pawpaw leaves exhibited weak antioxidant activities in vitro at all the concentrations investigated. Mango leaves had the highest total phenolic concentration (128 mg mL-1) at the maximum extraction time (50 min). At 50 min extraction time both the aqueous extracts of the two plants demonstrated maximum antioxidants activity (86.95% for aqueous extract of Mangifera indica and 89.70% for Pawpaw aqueous extract). A non-significant moderate positive correlation was observed between total phenolic concentration and antioxidant activity of aqueous extract of Mangifera indica and that of Pawpaw leaves (r = 0.592; p = 0.05 for Mangifera indica; r = 0.469; p = 0.05 at 20 min extraction time).
B.M. Olabinri, M.T. Olaleye, O.O. Bello, L.O. Ehigie and P.F. Olabinri, 2010. In vitro Comparative Antioxidative Potentials of Mango and Pawpaw Leaf Extracts. International Journal of Tropical Medicine, 5: 40-45.