Protective effect of thiourea, a hydroxyl-radical scavenger, on curcumin-induced chromosomal aberrations in an in vitro mammalian cell system.

Natural dietary antioxidants are extensively studied for their ability to protect cells from damage to DNA, protein, and lipids induced by antitumor agents or radiation that leads to the generation of free radical in normal cells in vivo and in vitro. Curcumin is a natural antioxidant known to possess therapeutic properties and has been reported to scavenge free radicals and to inhibit clastogenesis in mammalian cells. However, curcumin has been reported to induce a significant increase in the frequency of chromosomal aberrations in Chinese hamster ovary (CHO) cells. To investigate whether the clastogenic activity of curcumin in CHO cells in culture can be ascribed to a pro-oxidant behavior, mediated by free radical generation, experiments were carried out with the combination of curcumin (15 microg/ml) and thiourea (10, 20, or 40 microg/ml), a potent hydroxyl radical scavenger. The results showed that the clastogenic action of curcumin was statistically decreased in a dose-dependent manner in the presence of thiourea. These data have shown that curcumin-induced chromosomal damage in CHO cells can be mediated by hydroxyl radical generation in the present experimental conditions. Teratogenesis Carcinog. Mutagen. 21:175-180, 2001. Copyright 2001 Wiley-Liss, Inc.