Synergistic antitumor effects of combined deguelin and cisplatin treatment in gastric cancer cells

Deguelin is a naturally occurring rotenoid with marked chemopreventive and antitumor activity. Cisplatin, characterized by damaging DNA, is widely used in the chemotherapy of malignancies, including gastric cancer. The present study investigated whether synergistic effects exist between the combination of deguelin and cisplatin, and the possible mechanism in vitro. The interactive effects of deguelin in combination with various concentrations of cisplatin were evaluated in the human gastric cancer MGC-803 cell line. The inhibition of cell proliferation was determined by 3-(4,5)-dimethylthiazol(-2-yl)-2,5-diphenyltetrazolium bromide assay and the mechanisms underlying the effects were further evaluated by western blot analysis. The results revealed that the combined treatment of deguelin and cisplatin exhibited a marked inhibition of MGC-803 cell proliferation when compared with that of the single therapies in vitro. In addition, isobologram analysis revealed that this combined treatment showed a synergistic effect. These observations may have promising therapeutic value for gastric cancer and thus warrant further investigation.