Trigonelline Ameliorates Oxidative Stress in Type 2 Diabetic Goto-Kakizaki Rats

Previously, we showed that trigonelline (TRG) exerts antidiabetic effects in type 2 diabetic Goto-Kakizaki (GK) rats and also lowers blood and liver thiobarbituric acid reactive substances and urinary 8-hydroxydeoxyguanosine when compared with those levels in GK control rats without TRG. These results suggested that TRG also mitigates oxidative stress, which accelerates diabetes. In this study, the mechanisms of TRG prevention of oxidative stress were determined by measuring erythrocyte and liver antioxidant enzyme activities, and expressions of genes associated with reactive oxygen species production, and carbohydrate and lipid metabolisms by DNA microarray. Erythrocyte and liver glutathione peroxidase, and liver catalase activities in the GK rats fed with TRG were significantly lower than those of the GK control rats. TRG downregulated the gene expressions involved with NADPH oxidase and mitochondrial electron transfer system when compared with those of the GK control group. These results suggested that mitigation of diabetes by TRG is mediated by its ameliorating effects on oxidative stress.