Esculin improves dyslipidemia, inflammation and renal damage in streptozotocin-induced diabetic rats

Increasing studies have shown that dyslipidemia and inflammatory responses play important roles in the progression of microvascular diabetic complications. Esculin (ES), a coumarin derivative, was extracted from Fraxinus rhynchophylla. The present study was to evaluate the potential effects of ES on lipid metabolism, inflammation responses and renal damage in streptozotocin (STZ)-induced experimental diabetic rats and explore the possible mechanism.

Diabetic rat model was established by administration high-glucose-fat diet and intraperitoneal injection of STZ 45 mg/kg. ES was administrated to diabetic rats intragastrically at 10, 30 and 90 mg/kg for 10 weeks respectively. The levels of triglycerides (TG), total cholesterol (T-CHO), low density lipoproteins (LDL), and high-density-cholesterol (HDL-C) in serum were measured. IL-1, IL-6, ICAM-1, NO, NAGL, and AGEs level in serum were detected by ELISA assay. The accumulation of AGEs in kidney tissue was examined by immunohistochemistry assay.

The results showed that ES could decrease TG, T-CHO, LDL levels in serum of diabetic rats in a dose dependent manner. ES also decreased IL-1, IL-6, ICAM-1, NO and NGAL levels in serum of diabetic rats in a dose dependent manner. Furthermore, ES at 30 and 90 mg/kg significantly decreased AGEs level in serum and alleviated AGEs accumulation in renal in diabetic rats.

Our findings indicate that ES could improve dyslipidemia, inflammation responses, renal damage in STZ-induced diabetic rats and the possible mechanism might be associated with the inhibition of AGEs formation.