Inhibitory effect of fumaric acid on 3-methyl-4'-(dimethylamino)-azobenzene-induced hepatocarcinogenesis in rats.

Fumaric acid (FA) was examined for its effect on hepatocarcinogenesis in rats fed 3-methyl-4'-(dimethylamino)azobenzene (3-Me-DAB). Male DONRYU rats were given approximately 0.5 g 3-Me-DAB by being fed a diet containing 0.06% 3-Me-DAB for 50 days; they were then given a diet containing 1% FA and drinking water containing 0.025% FA for 51 weeks. The administration of FA effectively suppressed the development of hepatocellular carcinoma, hyperplastic nodules, and hyperplastic areas in the livers of rats fed 3-Me-DAB.