Protective effects of curcumin on methylglyoxal-induced oxidative DNA damage and cell injury in human mononuclear cells

Aim: To examine the effect of curcumin on oxidative DNA damage and cell apoptosis and injury caused by the reaction of methylglyoxal(MG) with amino acids. Methods: We used DNA strand breaks to examine the effect of curcumin on oxidative DNA damage. In addition, reactive oxygen species(ROS) formation occurs in MG-treated mononuclear cells, so the effect of curcumin on ROS generation was measured using 2',7'-dichlorofluorescin diacetate(DCF-DA) as the detection reagent. Moreover, the impact effects of curcumin on MG-induced cell apoptosis and ROS injury were analyzed by TUNEL and ELISA assay. The collagen I attachment ability of mononuclear cells was examined by trypan blue staining. Results: Our results revealed that curcumin prevented MG/lysine-induced oxidative stress and DNA damage. Curcumin also inhibited MG-induced apoptosis and generation of ROS in mononuclear cells. MG-treated mononuclear cells displayed a lower degree of attachment to collagen (the major component of the vessel wall subendothelium), whereas cells pretreated with curcumin before MG treatment exhibited restored affinities for collagen. Conclusion: These results demonstrated that oxidative stress plays a role in MG-induced cell injury and alterations in attachment ability, and that curcumin blocks these effects by virtue of its antioxidant properties.