Effects of curcumin on nitrosyl-iron complex-mediated DNA cleavage and cytotoxicity.

Combination therapy aims to improve the pharmaceutical efficacy of different drugs, thus lowering the dosages used and reducing the side effects. However, interactions between individual drugs may also occur and lead to uncertain consequences. This study demonstrated that curcumin, a natural phenolic compound found in the rhizomes of turmeric, could either inhibit or enhance DNA cleavage caused by the synthetic nitrosyl-iron complex NC10 ([Fe 2 (C 2 H 5 OS) 2 (NO) 4 ]). Without UV irradiation, higher concentrations of curcumin protected DNA from being cleaved by NC10. Conversely, in the presence of lower concentrations of curcumin (