Protective effects of black onion polysaccharide on liver and kidney injury in T2DM rats through the synergistic impact of hypolipidemic and antioxidant abilities

In this study, the synergistic effects of black onion on the hypolipidemic and antioxidant activities in T2DM rats induced by a high-fat-diet and alloxan were investigated. The results showed that the fasting blood glucose of diabetic rats was significantly decreased after treatment with black onion polysaccharide (p < 0.01). Blood lipid analysis indicated that black onion polysaccharide could significantly improve the abnormal metabolism of blood lipids caused by diabetes. In addition, the MDA and ROS of the diabetic rats treated with black onion polysaccharide were significantly reduced; moreover, SOD was increased, indicating the excellent antioxidant activity of black onion polysaccharide. A histological examination clearly showed that black onion polysaccharide could improve the histological morphology of the liver and kidney. Furthermore, the indices of liver and kidney function were restored. These results indicate that black onion polysaccharide can reduce blood glucose and simultaneously show synergistic effects of hypoglycemic and antioxidant activities in diabetic rats. Therefore, black onion polysaccharide may alleviate liver and kidney function injury by improving the "two-hit" mechanism and can thus be used as a potential functional food to prevent diabetes and its complications.