Chemopreventive potential of kimchi, an ethnic food from Korea, against colorectal carcinogenesis associated with red meat intake

Abstract

Kimchi, the traditional fermented vegetables with seasonings from Korea, is globally renowned as healthy food with anticancer properties. Colorectal cancer is the world’s third leading cancer with an increasing incidence rate over the past years. High red meat intake is strongly associated with colorectal cancer, and the World Health Organization has identified red meat as probably carcinogenic to humans (Group 2A). This study aimed to investigate the chemopreventive potential of cabbage kimchi against the promotion of colorectal cancer by red meat in vivo using carcinogen-injected rats. Rats were fed by AIN-76 diet enriched in freeze-dried beef sirloin supplemented or not with kimchi powder for 120 days prior to killing. Kimchi supplementation at moderate (5%) and high (10%) concentration significantly suppressed the formation of precancerous lesions in the colon of red meat-fed rats. Using fecal water, the aqueous extract of feces, we found out that kimchi supplementation limited iron-mediated oxidation and reduced lipid peroxidation in the feces of rats. Furthermore, kimchi supplementation reduced the toxicity of fecal water of red meat-fed rats toward human colonic epithelial cells in vitro by suppressing the formation of cellular reactive oxygen species (ROS). The chemopreventive effects of kimchi were associated with the acidification of fecal matrix and increase in fecal lactic acid bacteria (LAB). Gene expression analysis in the colon of rats demonstrated that kimchi supplementation prevented colorectal carcinogenesis by up-regulating the expression of tumor-suppressor genes and antioxidant enzymes, as well as by down-regulating the expression of proinflammatory proteins. Taken together, our findings suggested that kimchi consumption is correlated with lower promotion of colorectal cancer associated with red meat intake.