Differential effects of polyphenols-enriched extracts from hawthorn fruit peels and fleshes on cell cycle and apoptosis in human MCF-7 breast carcinoma cells

This study was to investigate the anticancer effects of the peel polyphenolic extract (HPP) and flesh polyphenolic extract (HFP) from hawthorn fruit in human MCF-7 breast cancer cells. It was found that the polyphenol and flavonoid contents of HPP were significant higher than that of HFP. Both HPP and HFP inhibited cell growth in a dose-dependent manner with the IC₅₀ of 88.6 μg/mL and 175.5 μg/mL, respectively, suggesting that HPP was more effective against MCF-7 cells than HFP. Flow cytometric analysis revealed that both HPP and HFP mediated the cell-cycle arrest at the S-phase, and also dose-dependently led to apoptosis of MCF-7 cells via the mitochondrial pathway, as evidenced by the activation of caspase-3 and caspase-9 and the elevation of intracellular ROS production. All these findings indicate that hawthorn fruit, especially its peel, is an excellent source of natural chemopreventive agents in the treatment of breast cancer.