Induction of Apoptosis in MCF-7 Breast Cancer Cells by Sri Lankan Endemic Mango (Mangifera zeylanica) Fruit Peel through Oxidative Stress and Analysis of its Phytochemical Constituents

Abstract

In this study, in vitro cytotoxic and apoptotic effects of the organic extracts (hexane, chloroform, ethyl acetate and methanol) of Mangifera zeylanica fruit peel and flesh on estrogen receptor positive MCF-7 cancer cells were examined. Chloroform extract of the peel was found to be cytotoxic to cancer cells (IC50 78.46 ± 1.7 µg/mL) while none of the flesh extracts were cytotoxic. Caspase 7 activity was increased and DNA fragmentation as well as morphological features of apoptosis shown by acridine orange/ethidium bromide and Hoechst (33258) staining occurred in response to the chloroform extract of the peel. Peel chloroform extract also increased production of reactive oxygen species, malondialdehyde, glutathione-S-transferase and super oxide dismutase and depleted glutathione levels. The overall results of our study suggest that the peel chloroform extract can induce breast cancer cell apoptosis, perhaps by activation of an oxidative stress mechanism. Practical Applications Mangifera zeylanica (Sri Lankan endemic mango) is a plant endemic to Sri Lanka with edible fruits. Traditional Ayurvedic practitioners have used the bark of this plant for the treatment of some cancers. In the present study, the ability of Sri Lankan endemic mango fruit peel and flesh to inhibit MCF-7 breast cancer was explored. Only the chloroform extract of the fruit peel exhibited the capacity to mediate apoptosis via oxidative stress mechanism and this activity appeared to be due to the presence of some bio-active phytochemicals in the peel. This preliminary observation provides a rationale for use of dried M. zeylanica fruit peel as a cheap anticancer dietary supplement in Sri Lanka.