Abstract

BACKGROUND
Magnesium lithospermate B(LAB), an active component isolated from Salvia milltiorrhizae, has been reported to have renoprotective effects in type 1 diabetic animal model. The purpose of this study was to examine the effects of LAB on the prevention of diabetic nephropathy in Otsuka Long-Evans Tokushima Fatty(OLETF) rat which is regarded as an animal model of type 2 diabetes. METHODS: Ten microgram of LAB/kg or Vehicle(PBS) was given orally once daily to 10-week-old male OLETF rats and LETO rats for 40 weeks. Intra-peritoneal glucose tolerance test was performed at 50 weeks. 24 hr urinary protein excretion amounts were measured. Lipid peroxidation, TGF-beta1 and ED-1 of renal cortex were measured. RESULTS: The mean body weight of LAB+OLETF was not significantly different from that of OLETF rats. LAB treatment decreased proteinuria, lipid peroxidation, and free fatty acid in OLETF rats without decrease in the plasma glucose concentration. Also, LAB inhibited the progression of glomerular hypertrophy and mesangial expansion. LAB effectively decreased ED-1 positive cells, ECM expansion, and TGF-beta1 level in the renal cortex of OLETF rats. CONCLUSIONS: These results suggest that the beneficial effects of LAB on the diabetic renal damage in the OLETF rats may depend on a mechanism of decreasing oxidative stress. LAB might be a new therapeutic agent for the prevention of nephropathy in type 2 diabetes as well as type 1 diabetes.

• Keywords: Lithospermate B;OLETF rats;Diabetic nephropathy