Mango (Mangiferaindica L.) Peel Extracts Inhibit Proliferation of HeLa Human Cervical Carcinoma Cell via Induction of Apoptosis

Flesh and peel extracts of five mango varieties were compared for their antioxidant and antiproliferative activities. Fozli peel (FP) extract was found to have the highest antioxidant activity and to significantly inhibit the proliferation of HeLa human cervical carcinoma cells in a dose-dependent manner. Hoechst 33342 staining revealed apoptotic nuclei with condensed chromatin, and cell growth arrest was confirmed by flow cytometry. Apoptotic signaling induced by FP extract was characterized by an increased Bax/Bcl-2 ratio and down-regulation of Bcl-2. Moreover, FP extract treatment triggered the proteolytic activation of caspases-3, -8, and -9 and the degradation of poly ADP-ribose polymerase in HeLa cells. These results indicate that FP is an excellent source of phenolic and/or flavonoid compounds, and may have applications in the treatment of human cervical carcinoma and as an antioxidant in the food and pharmaceutical industries. Gas chromatography-mass spectrometry analysis of FP extract revealed that 2,5-dihydroxyphenol was detected with highest amount and other compounds such as 5-hydroxymethyl-2-furancarboxaldehyde, pentadecanoic acid, (Z,Z)-9,12-octadecadienoic acid, and 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one were also found in high amounts.