In vitro Antioxidant Activity of Mangifera indica Leaf Extracts

In this study, we aimed to identify the utility of pruned mango (Mangifera indica ‘Irwin’) leaves as a resource for ingredients with antioxidant activity. Firstly, we examined the antioxidant activity of extracts obtained from the pericarps, flesh, flowers, barks, seeds, young dark reddish brown leaves (YDL-ext), young yellow leaves (YYL-ext), and pruned old dark green leaves (OML-ext) obtained from ‘Irwin’ mango. Among them, methanolic extract of flower and OML-ext showed the most potent 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and superoxide dismutase (SOD)-like activity. The flesh extract showed weak DPPH radical scavenging activity, but did not show SOD-like activity. Secondly, we investigated the relationship between the maturation of leaves and their antioxidant activity by considering the contents of their two active polyphenolic components, 3-C-β-D-glucosyl-2,4,4’,6-tetrahydroxybenzophenone (1) and mangiferin (2), in addition to chlorophyll (3) and anthocyanins represented by cyanidin-3-O-glucoside (4). The DPPH radical scavenging activity of YDL-ext, YYL-ext and OML-ext were mainly attributable to 1, 2 and 3, whereas their SOD-like activity was partly attributable to 2. The DPPH radical scavenging and SOD-like activities of YDL-ext and YYL-ext were attributable to 1 and 2. These activities were also due to anthocyanins whose content is highest in YDL-ext. Considering the amounts of leaves obtained from pruning, old dark green leaves may be a reasonable natural resource for preparing cosmetics and/or supplemental ingredients with health-enhancing properties, antioxidant activity and inhibitory effect on AGEs formation and pancreatic lipase.