Ameliorative effects of protodioscin on experimental diabetic nephropathy

Background: Diabetic nephropathy is one of the most common and serious complications of diabetes mellitus. Hypothesis/purpose: The present study aimed to investigate the effects of protodioscin on renal damage in highfat diet-fed and streptozotocin-induced diabetic rats. Methods: After 4 weeks of feeding a high-fat diet, male Sprague-Dawley rats were injected 35 mg/kg streptozotocin intraperitoneally. The diabetic rats were divided into 4 groups, and treated orally with carboxymethylcellulose sodium, metformin, or protodioscin (20 or 40 mg/kg). After 12 weeks of treatment, blood, urine, and renal tissue were collected for biochemical and histological examination. Results: Protodioscin significantly reduced the levels of blood glucose, serum creatinine, and blood urea nitrogen, and also the excretion of urinary protein and albumin in diabetic rats. Histological examinations showed that protodioscin ameliorated the diabetes-induced glomerular and tubular pathological changes. Furthermore, protodioscin significantly reduced the renal concentrations of total cholesterol, triglycerides, free fatty acids, phospholipids, and TNF-alpha. Conclusion: These results indicate that protodioscin has ameliorative effects on diabetic nephropathy.