Dietary flavonoids against various breast cancer subtypes: a molecular docking study

Breast cancer is female most frequent diagnosed cancer and the leading cause of cancer death. The consumption of dietary flavonoids is reported to cause significant breast cancer risk reduction. In vitro studies often used aglycone flavonoids rather than its conjugated form that actually present in human body. Thus its mechanism against breast cancer has not been elucidated completely. The present study aimed to investigate the possible mechanism of dietary flavonoids against breast cancer by in silico study. Conjugated flavonoids were docked to ER (estrogen receptor), HER2 (human epidermal growth factor receptor 2) and EGFR (epidermal growth factor receptor) kinase domains. The molecular docking of 22 flavonoid conjugates towards EGFR and HER2 kinase domain, and ER was successfully performed. Potential binders to proteins: epicatechin conjugates to ER (-8.7 kcal/mol), isoflavone conjugates to HER2 kinase domain (-10.7 kcal/mol), and epigallocatechin and epicatechin conjugates to EGFR kinase domain (-9.2 kcal/mol), were suggested. Supported by other studies, conjugated flavonoids may exert similar inhibitory and agonistic properties to their parent flavonoids. Taken together, the present study showed possible effects of dietary flavonoids against various breast cancer subtypes.