Anti-hyperglycaemic and anti-hyperlipidaemic effects of black and red rice in streptozotocin-induced diabetic rats

Increasing numbers of diabetic patients, especially those with type II, can link their condition to changes in eating habits. Black rice and red rice are not only a source of carbohydrate but also rich sources of antioxidants, especially proanthocyanidins and anthocyanins. This study determines the effect consuming a black rice extract (BRE) or a red rice extract (RRE) on streptozotocin-induced diabetic rats. Blood levels of glucose, triglycerides, and cholesterol in the diabetic group were determined and compared to that of the control group. The results demonstrate that consumption of BRE, 50 mg/kg body weight (BW), or RRE, 100 mg/kg BW, could significantly reduce the blood glucose level of the diabetic rats after eight weeks. Consumption of BRE, 100 mg/kg BW or RRE, 50 mg/kg BW, also clearly decreased the triglyceride level. The cholesterol level in the diabetic group fed with BRE or RRE decreased as well. Thus daily consumption of black rice, red rice, or having their extracts in food supplements may prevent the onset of diabetes.