The polyphenolic compounds
curcumin and
quercetin increased sensitivity of
ovarian cancer cells (CAOV3 and SKOV3) to
cisplatin. The effect was obtained when the compounds were added simultaneously with
cisplatin, as well as when they were added 24 h before. High serum levels of certain
cytokines, for example
interleukin-6 (IL-6), have been associated with poor prognosis and
cisplatin resistance in various forms of
cancer. Furthermore, it has been hypothesized that
cytokines may increase proliferation,
metastasis, and stimulate production of detoxification
enzymes and multi-drug resistant
proteins.
Curcumin inhibits the production of many
cytokines. The two ovarian cell lines differ significantly in
IL-6 production, and correspondingly the high producer, CAOV3, was less susceptible to
cisplatin.
Curcumin inhibited the production of
IL-6 in this cell suggesting that one of the mechanisms for synergy between
cisplatin and
curcumin was by reducing the autologous production of
IL-6. However, the synergy was also observed in the low
IL-6 producer, SKOV3, indicating that the action was most probably a result of multiple targeting. In sum, this study suggests that the compounds,
curcumin and
quercetin, potentially may be useful for enhancing drug sensitivity in certain
cancer.