Effects of high-fiber rice Dodamssal (Oryza sativa L.) on glucose and lipid metabolism in mice fed a high-fat diet

Abstract

We investigated the effects of high amylose rice variety, Dodamssal (DO) (Oryza sativa L.), on glucose homeostasis and lipid metabolism in mice. Experiment 1: Oral administration of DO for 1 week significantly improved glucose and insulin tolerance (p ˂ .001) and reduced plasma triglyceride and low-density lipoprotein cholesterol concentrations. Experiment 2: Administration of DO-containing diet for 5 weeks also significantly reduced fasting glucose concentrations and hepatic lipid accumulation. DO induced GLP-1, adiponectin, and PYY levels. In the liver, DO suppressed the gene expression of G6pc, key gene in gluconeogenesis and induced AKT phosphorylation. DO increased fecal bile acid excretion regulating the expression in key genes in bile acid metabolism. DO suppressed plasma Trimethylamine N-oxide and intestinal lipopolysaccharide concentrations. DO may be achieved the hypolipidemic effects by direct activation of hepatic Ppar alpha expression and its responsive genes regulating hepatic fatty acid uptake and beta-oxidation, while downregulating the hepatic fatty acid synthesis Our results demonstrate that high-fiber rice, DO, might be a potential supplement for the amelioration of insulin resistance and hyperlipidemia.

Practical applications The results from the present study suggest that newly developed DO (Oryza sativa L.) high amylose rice strain may improve insulin sensitivity and activates the Akt pathway. DO consumption tends to counteract the deleterious effects characterized during the intake of high-fat-diet related to plasma TG, ALT, and AST concentrations. Therefore, DO supplementation might be a potential adjuvant to ameliorate dyslipidemia and adiposity.