Preventive effects of rice bran oil on 1,2-dimethylhydrazine/dextran sodium sulphate-induced colon carcinogenesis in rats

This study included F344 rats which were fed AIN-93G-based 14% high-fat diets and were divided into the following six groups: Groups B and N, 14% soybean oil (SO); group P, 14% SO containing 0.04% piroxicam; group L, 5% rice bran oil (RBO) and 9% SO; group M, 9% RBO and 5% SO; and group H, 14% RBO. All the rats—except those in group B—were administered 1,2-dimethylhydrazine/dextran sodium sulphate to induce colitis-related colon carcinogenesis. The rats were sacrificed, and their colons were removed to examine aberrant crypt foci (ACF) and mucin-depleted foci (MDF). The results revealed that the rats from all the RBO group rats exhibited significantly reduced colon tumour formation, MDF, and ACF, especially sialomucin (SIM)-producing ACF. The hepatic antioxidant status, including the glutathione (GSH) and thiobarbituric acid reactive substance levels as well as superoxide dismutase and catalase activities, was superior among the RBO groups, which might contribute to the potential of RBO with respect to delaying colon carcinogenesis.