Chemopreventive Effects of Edible Canna (Canna edulis Kerr.) Against Colorectal Carcinogenesis: Effects on Expression of Adenomatous Polyposis Coli and Inducible Nitric Oxide Synthase in Rat Inflammatory Model

摘要

Objective: Dietary high fibre and calcium intake has been suggested to reduce colorectal cancer risk. However, thereis limited information available regarding the potential of edible canna (Ganyong), with high dietary fibre and calciumcontent, to act as a preventive agent for colorectal cancer. This experimental study was conducted to investigate thepreventive effect of Ganyong in reducing colorectal carcinogenesis with attention to effects on adenomatous polyposiscoli (APC) and inducible nitric oxide synthase (iNOS) expression. Methods: Thirty male Wistar rats were dividedinto 5 equal groups; a normal control group without azoxymethane/dextran sodium sulphate (AOM/DSS) inductionand Ganyong, a ‘cancer’ control group with AOM/DSS induction only, and three treatment groups with AOM/DSSinduction and different percentages (5%, 10% and 20%) of Ganyong. Paraffin-embedded sections of rat colon tissuewere analysed by haematoxylin-eosin and immunohistochemical staining against antibodies against APC and iNOS.Variation in rates of APC and iNOS expression were analyzed using the Kruskal-Wallis test followed by the Dunn’stest (SPSS statistic version 24). Pthe expression of APC (p=0.013) and iNOS (p=0.013) compared to the normal control group. APC expression in thetreated groups was lower than in the ‘cancer’ control group (p=0.049), especially in the 10% Ganyong group (p=0.02).In contrast, there was no significant variation among the treated groups regarding iNOS expression. Histopathologicalfeatures of the colon supported the data for APC and iNOS expression. Conclusion: This study indicated potentialchemopreventive effects of Ganyong reducing expression of factors contributing to colorectal carcinogenesis.