[MDR-reversing effect of two components of catechin on human hepatocellular carcinoma BEL-7404/Adr in vitro].
OBJECTIVE
Catechin is composed of a variety of components,some of which have anti-cancer activity. There was no report on effect of catechin on the multidrug resistance of hepatocellular carcinoma so far. The aim of this study was to investigate the MDR-reversing effect of two components of catechin on human hepatocellular carcinoma BEL-7404/Adr in vitro and its potential mechanism.


METHODS
MTT was used to test the toxicity of the two components of catechin. The concentration of the drugs inside the cells was determined by fluorospectro-photometry and the expression of MDR1 was measured by RT-PCR.


RESULTS
The inhibition rates of BEL-7404/Adr caused by two components of catechin were less than 10% under the dose of 100 mg/L. Epicatechin gallate (ECG) in 60 mg/L or epigallocatechin gallate (EGCG) in 14 mg/L has slight cytotoxicity, but they could decrease the IC(50) of adriamycin (ADM) for BEL-7404/Adr from 36 mg/L to 2.3 mg/L or 1.9 mg/L, respectively, and the reversing folds were 15.8 and 19.2, respectively. The combined administration could increase the concentration of ADM in BEL-7404/Adr cells from 0.76 microg/10(8) cells-2.55 microg/10(8) cells to 2.04 microg/10(8) cells -9.28 microg/10(8) cells (P< 0.01). The expression of MDR1 was down-regulated by 27.6% and 41.3%, respectively. Furthermore, EGCG is the stronger one.


CONCLUSIONS
ECG and EGCG can reverse the multi-drug resistance of human hepatocellular carcinoma in vitro. The possible mechanism is related to down-regulating the expression of MDR1 and raising the concentration of drugs inside the cells.
Liang
Gang
G
Department of Pharmacology, Guangxi Medical University, Nanning, Guangxi, 530021, PR China. Lianggang22@yahoo.com.cn
Zhang
Su
S
Huang
Zhi-Ming
ZM
Tang
An-Zhou
AZ
D006528:Carcinoma, Hepatocellular / Q000188:drug therapy*; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology*; D045744:Cell Line, Tumor; D004317:Doxorubicin / Q000493:pharmacokinetics; D018432:Drug Resistance, Multiple / Q000187:drug effects*; D019008:Drug Resistance, Neoplasm / Q000187:drug effects*; D006801:Humans; D008113:Liver Neoplasms / Q000188:drug therapy*
D004317:Doxorubicin; D002392:Catechin; C062669:epicatechin gallate; C045651:epigallocatechin gallate