Anticlastogenic activity of cacao: inhibitory effect of cacao liquor polyphenols against mitomycin C-induced DNA damage.

Oxidative DNA damage has been implicated as a factor playing a role in mutagenesis and carcinogenesis. We investigated the anticlastogenic activity of cacao: the inhibitory effect of cacao liquor polyphenols on DNA strand cleavage induced by mitomycin C (MMC) in vitro and the anticlastogenic effect of cacao liquor extract against formation of micronuclei induced by MMC in bone marrow cells and peripheral blood cells of mice. In the DNA strand cleavage test, cacao liquor polyphenols inhibited cleavage of RFI DNA. In the micronuclei test, the frequency of occurrence of micronucleated cells among bone marrow cells and peripheral blood cells were reduced significantly when cacao liquor extract was administered orally to mice 6 h before intraperitoneal injection of MMC. These findings suggest that cacao liquor polyphenols are effective in preventing DNA damage, and one of the mechanisms of action might involve scavenging of active oxygen radicals generated in reactions initiated by MMC.