Anti-proliferation effect on human breast cancer cells via inhibition of prb phosphorylation by taiwanin E isolated from Eleutherococcus trifoliatus.

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PubMedID: 25918798

Wang HC, Tseng YH, Wu HR, Chu FH, Kuo YH, Wang SY. Anti-proliferation effect on human breast cancer cells via inhibition of prb phosphorylation by taiwanin E isolated from Eleutherococcus trifoliatus. Nat Prod Commun. 2014;9(9):1303-6.
Eleutherococcus trifoliatus has been used as a folk medicine since ancient times, especially as refreshing qi medicines. In our current study, taiwanin E, which possesses strong cytotoxicity, was isolated from the branches of E. trifoliatus by using a bioactivity guided fractionation procedure. Taiwanin E presented a potent anti-proliferation activity on the growth of a human breast adenocarcinoma cell line (MCF-7), with an IC50 value for cytotoxicity of 1. 47 µM. Cell cycle analysis revealed that the proportion of cells in the G0/G1 phase increased in a dose-dependent manner (from 79. 4% to 90. 2%) after 48 h exposure to taiwanin E at a dosage range from 0. 5 to 4µM. After treatment with taiwanin E, phosphorylation of retinoblastoma protein (pRb) in MCF-7 cells was inhibited, accompanied by a decrease in the levels of cyclin D1, cyclin D3 and cyclin-dependent kinase 4 (cdk4) and cdk6; in addition, there was an increase in the expression of cyclin-dependent kinase inhibitors p21(WAF-1/Cip) and p27(Kip1). THE RESULTS
suggest that taiwanin E inhibits cell cycle progression of MCF-7 at the G0/G1 transition.The results suggest that taiwanin E inhibits cell cycle progression of MCF-7 at the G0/G1 transition.