Beneficial influence of phosphorylated parboiled dehusked red rice (Oryza sativaL.) in streptozotocin-induced diabetic rats

Abstract

Red rice (Oryza sativa L.) consumed in most Asian countries is widely considered as nutritional and phytochemical enriched rice with health implications. In the present study, we prepared parboiled and parboiled cross-linked (phosphorylated) whole red rice and their beneficial effect was investigated in streptozotocin-induced diabetic rats. Groups of diabetic rats (n¼8 per group) were maintained on raw whole red rice, parboiled whole red rice, and parboiled cross-linked whole red rice at 62% level in the diet for 6 weeks. The raw, parboiled and parboiled cross-linked whole red rice showed a significantly lower glycemic response in normal rats compared to that of white (polished) rice. All the three whole red rice forms exerted favorable influences in diabetic rats by improving the body weight and reducing hyperglycemia compared to control diet fed rats (p<0.05). The characteristic diabetic complications such as severe glucosuria, proteinuria, blood urea, and nephropathy were notably reduced (p<0.05). These red rice preparations also significantly decreased blood cholesterol and triglyceride concentrations in diabetic rats with a higher effect in the parboiled cross-linked rice group (p<0.05).Histopathological examination of kidney sections revealed shrunken glomeruli in diabetic control rats, while glomeruli were nearly normal in all the three dietary intervention groups. Thus, the present animal study which evidenced the hypoglycemic, hypocholesterolemic, hypotriglyceridemic, and renal protective properties of all the three forms of whole red rice, with highest hypolipidemic effect by parboiled cross-linked red rice suggests their utility as a functional ingredient in diets for diabetics.