Antioxidant activities, a-glucosidase inhibitory in vitro and effects of Lysimachia paridiformis Franch. var. stenophylla Franch. on alloxan-induced diabetic mice in vivo

To investigate the antioxidant and α-glucosidase inhibitory activities in vitro and effects ofLysimachia paridiformis Franch. var. stenophylla Franch (LPF) on alloxan-induced diabetic mice in vivo, 96-microplate-based method was used to assay α-glucosidase inhibitory activity, and antioxidant activity was determined by the method of DPPH, ABTS and FRAP. The model of diabetic mice was induced by alloxan. Extract of n-BuOH (LPFBU, IC50 = 20.00 μg/ml) had the highest α-glucosidase inhibitory activity in three extracts. LPFBU had the highest antioxidant activity (DPPH: IC50=15.69 μg/ml, ABTS: IC50=11.19 μg/ml and FRAP = 756.40±21.21 μmol TE/g respectively). Compared with diabetic control mice, oral administration of EtOAC extract (LPFEA, 1000,500 mg/kg, respectively) significantly decreased fasting blood glucose, serum TC, TG and MDA levels in diabetic rats, while it significantly increased liver glycogen content and increased SOD levels without statistical significance. The results indicated that LPFBU and LPFEA exhibited the higher activity of α-glucosidase inhibitory and a certain antioxidant activity. LPFEA has some good antidiabetic activity and good effects on diabetes complications. It may be useful in prevention and treatment of diabetes and diabetes-associated diseases.   Key words: Lysimachia paridiformis Franch. var. stenophylla Franch., α-glucosidase inhibitory activity, antioxidant activity, diabetes.