Anticarcinogenic action of apple pectin on fecal enzyme activities and mucosal or portal prostaglandin E2 levels in experimental rat colon carcinogenesis.

Pectin is a partially methoxylated polymer of galacturonic acid obtained from fruits. Among pectin, apple pectin exerts stronger bacteriostatical action on Staphylococcus aureus, Streptococcus faecalis, Pseudomonas aeruginosa and Escherichia coli in comparison with citrus pectin. In this study, we used water-soluble methoxylated pectin from apple. The diet, supplemented by 20% apple pectin, significantly decreased the number of tumors and the incidence of colon tumor. PGE2 level in distal colonic mucosa in 20% apple pectin fed rats were lower than those in basal diet fed rats. Fecal beta-glucuronidase activities in the apple pectin fed group, which has been considered a key enzyme for the final activation of Dimethylhydrazine metabolism to carcinogens in the colonic lumen, were signifieantly lower than those in control group at initiation stage of carcinogenesis. In the case the concentrations of beta-glueosidase and azoreductase were also decreased. The effect of apple pectin on the colon carcinogenesis may partially depend on PGE, concentration decrease in colonic mucosa and on the type of pectin, also related to fecal enzyme activities.