Resistant starch-rich wx/ae brown rice prevents insulin resistance and hypertriglyceridaemia in type 2 diabetic NSY mice

• A rice cultivar called ‘wx/ae’ is rich in resistant starch.
• The effect of wx/ae brown rice on type 2 diabetes was examined in the mouse model.
• Intake of wx/ae brown rice prevented insulin resistance and hypertriglyceridaemia.
• Gene expression analysis in the liver and white adipose tissue was carried out.

A rice cultivar called ‘wx/ae’, double mutant in waxy (wx) and amylose extender (ae) genes, is rich in resistant starch. Type 2 diabetic NSY mice were fed a test diet containing 30% roasted wx/ae brown rice (wx/ae group) or its parental rice cultivar Kinmaze brown rice (WT group) for 16 weeks. The insulin sensitivity of the wx/ae group was significantly higher than that of the WT group, and the concentrations of fasting plasma triacylglycerol and non-esterified fatty acids were lower. Gene expression analysis of the liver revealed that expression levels of insulin-dependent genes and bile acid-related genes in the two groups were significantly different. Moreover, expression of the G protein-coupled receptor 43 gene in the epididymal white adipose tissue was significantly higher in the wx/ae group. These results indicate that wx/ae brown rice is a good candidate food for the prevention of type 2 diabetes and hypertriglyceridaemia.