Abstract

The antioxidant capacity of Indigofera stachyodes Lindl. root (ISR) extract had been determined by using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azinobis (3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS and ferric reducing antioxidant power (FRAP) assay, and α-glucosidase inhibitory activity using 96-microplate-based method test in vitro. Extracts of EtOAC (ISREA) and n-BuOH (ISRBU) were studied on protective effects of alloxan-induced diabetic rats in vivo. The results showed that ISREA and ISRBU had good total antioxidant activity in vitro, ISREA had the highest antioxidant activity (DPPH: IC₅₀ = 7.82 μg/ml, ABTS: IC₅₀ = 2.37 μg/ml and FRAP = 2270.80±8.48 μmol TE/g, respectively). Extracts of ISR showed higher α-glucosidase inhibitory activity. ISRBU (IC₅₀ = 7.01 μg/ml) had the highest α-glucosidase inhibitory activity. Compared with diabetic control mice, oral administration of ISREA and ISRBU could decrease fasting blood glucose and postprandial blood glucose without statistical significance. Administration of ISRBU (400 mg/kg) could significantly increase liver glycogen content and superoxide dismutase (SOD) levels and significantly decrease serum total cholesterol (TC), triglyceride (TG) and malondialdehyde (MDA) levels in diabetic rats.

Key words: Indigofera stachyodes Lindl. root, antioxidant activity, α-glycosidase inhibition activity, diabetes.