Effect of Curcuminoids on MDR-1 Gene Expression in Multidrug Resistance KBChR-8-5 Human Cervical Cancer Cell Line

Drug resistance is a major problem in cancer chemotherapy. The mechanism that has been most extensively investigated is the expression of the MDR-1 gene product, Pgp. The emergence of natural products as potential anti-MDR molecules is of particular significance, since many of these are essential components of the human diet, they are expected to possess fewer side effects and may possibly represent a new generation of MDR modulators. Curcuminoids are the major component present in turmeric. Here we demonstrate that curcuminoids inhibits the growth of drug resistant cancer cell lines (KBChR8-5) in a dose dependent manner, with IC50 values in the 5-25μM range. In addition, MDR-1 gene expression was studied in curcuminoids treatment, it revealed that among three curcuminoids curcumin treated cells showed down-regulation and other two curcuminoids showed mild change in MDR-1 expression in comparison with control. In conclusion the Pure curcumin displayed poor anti-cancer activity in KBChR8-5 cell line, but curcumin inhibits MDR-1 gene expression which implies that it is not directly involved in cytotoxicity when compared with other two curcuminoids instead it inhibits MDR-1 gene product, P-gp (efflux pump). Curcumin in combination chemotherapy may increase accumulation of cytotoxic drugs by blocking efflux pump and significantly enhance the anti-cancer activity in the treatment of various cancers related to multidrug resistance.