Extracts of citrus Sudachi peel attenuate body weight gain in C57BL/6 mice fed a high-fat diet

Citrus Sudachi is the special local product of Tokushima Prefecture, and over 98% of Sudachi consumed in Japan every year is produced in Tokushima Prefecture. In this study, we evaluated the function of sudachi peel extract (SPE) using an animal model of obesity. C57BL/6 mice were fed a high-fat diet containing 1% SPE powder. Treatment with SPE significantly decreased body weight compared to that of mice fed a high-fat diet. A significant difference in body weight was observed between the control and SPE groups from 7 weeks after the start of the experiment, the significant difference continued until the end of the 14-week experiment. Reduction of blood glucose levels following insulin administration in SPE-treated mice was grater than that in control mice. Determination of mRNA expression in adipose tissue showed that the expression level of TNF-α in the SPE group was significantly decreased compared to that on the control group. These results suggest that SPE potentially has the ability to attenuate body weight gain.