Radish (Raphanus sativus L. leaf) ethanol extract inhibits protein and mRNA expression of ErbB₂ and ErbB₃ in MDA-MB-231 human breast cancer cells

In this study, we investigated the effects of the ethanol extract of aerial parts of Raphanus sativus L. (ERL) on breast cancer cell proliferation and gene expression associated with cell proliferation and apoptosis in MDA-MB-231 human breast cancer cells. The MDA-MB-231 cells were cultured in the presence or absence of various concentrations (100, 200, or 300 ㎍/mL) of ERL. ERL significantly decreased cell proliferation after 48 h of incubation (P less than 0.05). The protein and mRNA expression of ErbB₂ were decreased significantly in a dose-dependent manner (P less than 0.05). The protein expression of ErbB₃ was decreased significantly at an ERL concentration of 300 ㎍/mL (P less than 0.05), and mRNA expression of ErbB₃ was decreased significantly in a dose-dependent manner (P less than 0.05). The protein expression of Akt was decreased significantly at the ERL concentration of 200 ㎍/mL (P less than 0.05), and the protein expression of pAkt was decreased significantly in a dose-dependent manner (P less than 0.05). The mRNA expression of Akt was decreased significantly at the ERL concentration of 200 ㎍/mL ERL (P less than 0.05). The protein and mRNA expression of Bax were increased significantly at ERL concentrations of 200 ㎍/mL or higher (P less than 0.05). The protein expression of Bcl₂ was increased significantly at ERL concentrations of 100 ㎍/mL or higher (P less than 0.05), and mRNA expression of Bcl₂ was increased significantly at an ERL concentration of 300 ㎍/mL (P less than 0.05). In conclusion, we suggest that Raphanus sativus, L. inhibits cell proliferation via the ErbB-Akt pathway in MDA-MB-231 cells.