Reversal Of Multidrug Resistance Of Human Hepatocellular Carcinoma Cells BEL-7404/Adr And Oral Carcinoma Cells KBV200 By Two Components Of Catechin In Vitro

OBJECTIVE To study the MDR-reversing effect of two catechin components on human hepatocellular carcinoma cells and oral carcinoma cells. METHODS CN1060488A patent was used and improved to isolate and purify two catechin components. MTT was used to test the resistance fold of carcinoma cells and the cytotoxicity of drugs. MDR] expression was detected by RT-PCR. The expression of P-gp and the accumulation of Rh-123 inside the cells was tested by FACS. Fluorospectrophotometry was used to test the concentration of drugs in the cells. In situ cell death of histochemistry and agarose electrophoresis were used to detect the apoptosis of carcinoma cells. The change of cell cycle was tested by Pi-staining and analyzed by FACS. RESULTS ECG and EGCG, two monomers of catechin have been isolated successfully. The IC50 of ADM on BEL-7404 and BEL-7404/Adr were 0.94mg/L and 36mg/L respectively. The IQo of VCR on KB and KBV200 were 0.036 mg/L and 1.91mg/L respectively. The resistance fold of BEL-7404/Adr and KBV200 was 38-fold and 53-fold respectively. The IQo of ECG was 504mg/L(BEL-7404), 2200mg/L (BEL-7404/Adr), 462 mg/L(KB), 1250mg/L(KBV200) respectively. The IC50 of EGCG was 545mg/L (BEL-7404), 1300mg/L (BEL-7404/Adr), 262mg/L (KB),480mg/L (KBV200) respectively.The reversing-fold of ECG (60mg/L) or EGCG(14mg/L) jointed with 2.3mg/L or 1.9mg/L ADM on BEL-7404/Adr was 15.8 and 19.2 respectively. The reversing-fold of ECG (80mg/L) or EGCG(30mg/L) jointed with 0.24mg/L or 0.14mg/L VCR on KBV200 was 8 and 13 respectively. Two monomers jointly administrated with ADM or VCR could decrease the expression of MDRj and P-gp, depress the transport ability of P-gp(P<0.01). The accumulation of chemicals in tumor cells was increased by catechin and chemicals jointly treated. The apoptosis of carcinoma cells was also enhanced and the cell cycle was blocked at S/G2 phase. CONCLUSION ECG and EGCG can reverse the multidrug resistance of BEL-7404/Adr and KBV200. The mechanism would be possibly related to decrease the expression of MDRj and P-gp, thereby increase the accumulation of chemicals inside carcinoma cells and enhance the apoptosis of carcinoma cells.