Lithospermic acid B (LAB), an active component isolated from Salvia miltiorrhizae,
has been reported to have renoprotective effects in type 1 diabetic animal models.
In the present study we investigated the effects of LAB on the prevention of diabetic
nephropathy in type 2 diabetic Otsuka Long-Evans-Tokushima Fatty (OLETF) rats. LAB
(20 mg/kg) was given orally once daily to 10-week-old male OLETF rats for 28 weeks.
Treatment of OLETF rats with LAB had little effects on body weight and blood glucose
levels. Treatment with LAB resulted in significant reduction in blood pressure. LAB
markedly attenuated albuminuria and significantly lowered levels of lipid peroxidation,
monocyte chemoattractant protein-1 (MCP-1), and transforming growth factor-beta (TGF-beta1)
expression in renal tissues of OLETF rats. In addition, LAB inhibited the progression
of glomerular hypertrophy, mesangial expansion, and expansion of the extracellular
matrix in the renal cortex. Collectively, these results suggest that LAB has beneficial
effects on the diabetic nephropathy in OLETF rats by decreasing blood pressure, oxidative
stress, and MCP-1 expression. Our results suggest that LAB might be a new therapeutic
agent for the prevention of nephropathy in type 2 diabetes.