Methyl gallate isolated from Mangifera pajang kernel induces proliferation inhibition and apoptosis in MCF-7 breast cancer cells via oxidative stress

Objective:To determine the lead bioactive compound in kernel extract of Mangifera pajang and its anti-cancer activity against human breast cancer cell lines with positive estrogen receptor(MCF-7).Methods:The methanolic extract of dried powder kernel of Mangifera pajang was exposed to column chromatography for isolation.The structural elucidation of the isolated compound was characterized using infrared,nuclear magnetic resonance,mass spectrometry.Furthermore,cytotoxicity,morphological changes,flow cytometry and cell cycle arrest analyses were performed to examine the mechanism of anti-proliferation and apoptosis induced by methyl gallate against MCF-7.Results:One compound was isolated from the methanolic extract of Mangifera pajang kernel and identified as methyl gallate.The flow cytometric results demonstrated induction of apoptosis in MCF-7 cells by three concentrations of methyl gallate.The cell cycle arrest showed a significant(P<0.05)decrease in cell progression at G2/M phase of MCF-7 after treatment with 100μM of methyl gallate.The cell percentage of early and late apoptosis was significant at 10 and 100μM of methyl gallate.Also,methyl gallate treatment induced up-regulation of reactive oxygen species levels in MCF-7 cells with a reduction in superoxide dismutase levels.Conclusions:These findings indicate that isolated methyl gallate from Mangifera pajang kernel extracts induces growth inhibition and apoptosis in MCF-7 cells via up-regulating oxidative stress pathway.