Protective Effects of Lithospermic Acid B on Diabetic Nephropathy in OLETF Rats Comparing with Amlodipine and Losartan

Abstract

Background: Lithospermic acid B (LAB), an active component isolated from Salvia miltiorrhizae, has been reported to have renoprotective effects in type 1 and type 2 diabetic animal models. We examined the effects of LAB on the prevention of diabetic nephropathy compared with amlodipine, a calcium channel blocker, and losartan, an angiotensin receptor blocker, in Otsuka Long-E vans-Tokushima Fatty (OLETF) rats, an animal model of type 2 diabetes. Methods: LAB (20 mg/kg), amlodipine (10 mg/kg), or losartan (10 mg/kg) was given orally once daily to 10-week-old male OLETF rats for 28 weeks. Results: None of LAB, losartan, and amlodipine exhibited effects on blo od glucose levels. Treatment with amlodipine or losartan resulted in similar reductions in blood pressure; however, LAB was less effective in lowering blood pressure. Albuminuria was markedly suppressed by losartan and LAB, but not by amlodipine. LAB treatment decreased levels of renal lipid peroxidation, monocyte chemoattractant protein-1 (MCP-1), and transforming growth factor-β1 (TGF-β1). Conclusion: These results suggest that LAB has beneficial effects on the diabetic nephropathy in OLETF rats by decreasing oxidative stress and inflammation as potent as losartan. (KOREAN DIABETES J 32:10~20, 2008)