Antidiabetic potential of salvianolic acid B in multiple low-dose streptozotocin-induced diabetes

Context: Salvianolic acids are the most abundant water-soluble compounds extracted from the herb Salvia miltiorrhiza L. (Lamiaceae) with antioxidant and protective effects. Objective: This study evaluates the antidiabetic effect of salvianolic acid B (Sal B) in multiple low-dose streptozotocin (MLDS)-induced diabetes in rat. Materials and methods: Rats were divided into control, Sal B40-treated control, diabetic, Sal B20-, and Sal B40-treated diabetic groups. Sal B was daily administered at doses of 20 or 40 mg/kg (i.p.), started on third day post-STZ injection for 3 weeks. Serum glucose and insulin level and some oxidative stress markers in pancreas were measured in addition to the oral glucose tolerance test (OGTT), histological assessment, and apoptosis determination. Results: After 3 weeks, treatment of diabetic rats with Sal B20 and Sal B40 caused a significant decrease of the serum glucose (p<0.05-0.01) and improvement of OGTT. Meanwhile, serum insulin was significantly higher in Sal B20- and Sal B40-treated diabetics (p<0.01) and treatment of diabetics with Sal B40 significantly lowered malondialdehyde (MDA) (p<0.05), raised glutathione (GSH) (p<0.05), and activity of catalase (p<0.01) with no significant change of nitrite. Furthermore, the number of pancreatic islets (p<0.05) and their area (p<0.01) was significantly higher and apoptosis reactivity was significantly lower (p