In vitro effect of quercetin on human gastric carcinoma: Targeting cancer cells death and MDR

The benefits of plant polyphenols as chemotherapeutic agents are of great interest due to their possible anti-cancerogenic activities. Results available up to now suggest that flavonoid quercetin induces lethal effect in many types of tumours and may sensitize resistant cells to drugs. The aim of our study was to examine the effect of quercetin on human gastric carcinoma cells and to determine mode of its action. Parental EPG85-257P cell line and its daunorubicin-resistant variant EPG85-257RDB were used as cell models. Our data revealed that quercetin exerted antiproliferative impact on studied cells (with IC50 value of 121 mu M after 72 h), mainly through induction of apoptosis. In sensitive cells cytostatic drug and flavonoid had synergistic effects, in EPG85-257RDB cells quercetin acted as a chemosensitizer. Its impact on resistance mechanism involved decrease of P-glycoprotein expression, inhibition of drug transport and downregulation of ABCB1 gene expression. The results demonstrate that quercetin may be considered as a prospective drug to overcome classical resistance in gastric cancer cells. (c) 2012 Elsevier Ltd. All rights reserved.