Preventive effect of caffeine and curcumin on hepato-carcinogenesis in diethylnitrosamine-induced rats.

Chemopreventive effects of caffeine and curcumin were evaluated in the diethylnitrosamine (DEN)-induced hepatocarcinogenic rat model. Animals injected with DEN for 10 weeks (G2-10w) and 14 weeks (G2-14w) were hepato-carcinogenic rats. Animals injected with DEN and treated with curcumin and caffeine for 10 weeks (G3-10w, G4-10w) and 14 weeks (G3-14w, G4-14w) were compared with those in G2. Macroscopic and microscopic features suggested that treatment with caffeine, but not curcumin, for 10 and 14 weeks was effective in inhibiting DEN-induced hepatocarcinogenesis. Immunohistochemical and western blot analysis with proliferating cell nuclear antigen and glutathione S-transferase-P antibodies also showed that expression levels of these hepato-carcinogenic markers were more efficiently reduced by treatment with caffeine than curcumin. Our data demonstrate that caffeine could be a more potent compound than curcumin for prevention of hepatocarcinogenesis in DEN-induced rats.