Abstract:

Objective：To investigate the effect of different RS4-type resistant starches on the mRNA expression of lipidmetabolism-related genes in mice with high-fat (HF) diet-induced obesity and to elucidate the underlying mechanism.Methods: Weight- and age-matched male C57BL/6J mice were fed for 12 weeks on a high-fat diet containing unmodifiedsweet potato starch (SPS), hydroxypropylated and cross-linked starch (HPCL), cross-linking and octenyl succinic anhydridemodified starch (CLOSA), citric acid-treated and acetylated starch (CAAC), respectively. After the feeding period, serumlipid levels, body weight and morphological changes of liver tissue in mice were examined. Meanwhile, the mRNAexpression levels of fatty acid synthese (FAS), sterol regulatory element binding protein-1c (SREBP-1), 3-hydroxy-3-methylglutary coenzyme A reductase (HMGCR) were examined. Results: The mice fed on the RS4 diet had significantlylower body weight. The expression level of SREBP-1c mRNA was significantly lower than in those fed on either unmodifiedstarch or the HF diet. The levels of serum triglyceride and the mRNA expression levels of FAS and HMGCR were alsoreduced in mice fed on the RS4 diet. Conclusion: Owing to the alteration of the expression of related genes, the mice fedon the RS4 diet had a significantly lower hepatic lipogenesis capacity in those with HF diet-induced obesity. In conclusion,dietary supplementation with RS4-type resistant starch attenuates high fat diet-induced obesity effectively, which may beattributable to the decreased lipogenesis in the liver.

Key words: resistant starch, lipid metabolism, hepatic function, gene expression, high-fat diet