Proanthocyanidin and sodium butyrate synergistically modulate rat colon carcinogenesis by scavenging free radicals and regulating the COX-2 and APC pathways

Abstract Background The purpose of this study was to explore the effects of sodium butyrate (NaB), grape seed proanthocyanidin extract (GSPE), or their combination against dimethylhydrazine (DMH)-induced aberrant crypt foci (ACF) formation, which is a proxy for colon carcinogenesis in the rat colon. Results After inducing colon cancer, all treatments markedly decreased the overall numbers of ACF, with the NaB–GSPE combination eliciting the most pronounced reduction. All the treatments significantly inhibited cell proliferation as indicated by the lower percentages of Ki67-positive cells in the colonic mucosa. Also, caspase-3-immunolabeled cells were found to be significantly increased after all treatments, indicating more apoptotic activity in the initiated colonocytes. Further, the treatments significantly modulated the levels of antioxidant biomarkers, including malondialdehyde, superoxide dismutase, reduced glutathione, and total antioxidant capacity, suggesting a potently induced antioxidant activity, especially after the combination treatment. All treatments, especially the combination, dramatically downregulated the expression of COX-2 and APC, both of which are directly linked to colon cancer. Conclusions NaB and GSPE exert potent anti-carcinogenic effects, both alone but more effectively in combination, in a rat colon cancer model. They could be important for colon cancer treatment and for adjuvant therapy in humans.