The antioxidant and antiproliferative properties of flesh and peel of mango (Mangifera indica L.) were
investigated. The cytoprotective effect of mango flesh and peel extracts on oxidative damage induced
by H2O2 in a human hepatoma cell line, HepG2, were determined, and the underlying mechanism was
examined by a single-cell electrophoresis assay (comet assay). Treatment of HepG2 cell with mango peel
extract prior to oxidative stress was found to inhibit DNA damage. The free radical scavenging activities
of mango flesh and peel extracts were evaluated by electron spin resonance (ESR). The mango peel extract
exhibited stronger free radical scavenging ability on 1,1-diphenyl-2-picrylhydrazyl (DPPH) and alkyl radicals
than mango flesh extract, regardless of ripeness. Similarly, peel extract exhibited significant antiproliferative
effect against all tested cancer cell lines, compared to that of flesh extract, in a dose-dependent
manner. The result also showed that the antiproliferative activity of mango flesh and peel extracts correlated
with their phenolic and flavonoid contents. Thus, mango peel, a major by-product obtained during
the processing of mango product, exhibited good antioxidant activity and may serve as a potential
source of phenolics with anticancer activity