Antidiabetic and antioxidant effects of extracts from Potentilla discolor Bunge on diabetic rats induced by high fat diet and streptozotocin.

OBJECTIVE

Potentilla discolor Bunge, commonly found at the north temperate and boreal zone, has been used for diabetes in China for a long time. Flavonoids and triterpenoids are two major types of compounds in P. discolor. This study was designed primarily to investigate the effects of total flavonoids extract (TFE) and total triterpenoids extract (TTE) of P. discolor Bunge on blood glucose, lipid profiles and antioxidant parameters on diabetic rats induced by high fat diet and streptozotocin.

METHODS

High fat diet-fed and streptozotocin-induced diabetic rats were treated with the TFE and TTE for 15 days, respectively. A range of parameters were tested including fasting blood glucose (FBG), serum insulin (SI), blood lipid profile, malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), glycosylated serum protein (GSP), and nitric oxide (NO).

RESULTS

Diabetic rats treated with TFE or TTE had decreased concentration of FBG and GSP compared with the control group. Meanwhile, the levels of serum total cholesterol (TC), triglycerides (TG) and low-density lipoprotein cholesterol (LDL-c) in the TFE or TTE treated diabetic rats were lower, and the high-density lipoprotein cholesterol (HDL-c) level was higher than in the control diabetic rats. Furthermore, the extracts treatment decreased the MDA and NO level, while increased SOD and GSH levels in diabetic rats. Histopathologic examination also showed that the extracts have protective effects on β-cells in diabetic rats which are supported by the increase of SI.

CONCLUSIONS

All these experimental results highlighted the hypoglycemic and hypolipidemic properties of the two extracts from Potentilla discolor Bunge on diabetes and its complications, possibly through a strong antioxidant activity and a protective action on β-cells.