Baicalein sensitizes hepatocellular carcinoma cells to 5-FU and Epirubicin by activating apoptosis and ameliorating P-glycoprotein activity

Hepatocellular carcinoma (HCC) has a dismal prognosis in part because of multi-drug resistance (MDR). Baicalein is a flavonoid extracted from Radix Scutellariae with anti-HCC activity. We tested the effects of Baicalein on multi-drug resistant HCC cells (Bel7402/5-FU) known to be resistant to the anticancer drugs 5-FU and Epirubicin. Flow cytometry analysis showed that treatment with 5 mu g/ml and 10 mu g/ml Baicalein resulted in increases in the intra-cellular concentrations of Rho123 and Epirubicin in the corresponding group of cells compared to untreated cells, illustrating that Baicalein reverses MDR in Bel7402/5-FU cells. Bel7402/5-FU cells displayed increased P-glycoprotein (P-gp)-mediated drug efflux. However, this efflux was inhibited in cells pre-incubated in Baicalein for 48 h. Moreover, Baicalein induced apoptosis and autophagy and decreased P-gp and Bcl-xl expression levels. All of these results indicate that Baicalein can reverse P-gp-mediated MDR in HCC and may thus be useful for the treatment of drug-resistant HCC.