Chemical composition, antioxidant and enzyme inhibitory properties of Ajuga parviflora Benth

Leaves of Ajuga parviflora Benth. (Lamiaceae) are widely used for treating hyperglycemia in the Himalayas' foothills of India. Hydroalcoholic and hexane leaf extracts of A. parviflora were evaluated for their inhibitory potential against carbohydrate-hydrolyzing enzymes linked with hyperglycemia (alpha-amylase and alpha-glucosidase) and the effect of extracts on glucose uptake by the yeast cells by in-vitro means. Additionally, antioxidant capacities of both extracts were tested and chemical compositions were also studied by gas chromatography-mass spectrometry (GC-MS). For estimation of the antioxidant capacities, total phenolic content (TPC), total flavonoid content (TFC), 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical (ABTS(center dot+)) scavenging activities, Fe3+ and MO(V) reducing assay were determined. GC-MS analysis revealed various biologically active compounds in which oleic acid, phytol and palmitic acid are present in both the extracts. The TPC and TFC contents were found higher in hydroalcoholic extract than hexane extract. The IC50 value of both hydroalcoholic and hexane extracts exhibited significant potency for DPPH (113.13 +/- 1.4 and 206.8 +/- 9.43 mu g/mL) and ABTS (156.67 +/- 6.76 and 128.2 +/- 1.71 mu g/mL) as well as for alpha-amylase (103.55 +/- 2.5 and 116.34 +/- 2.08 mu g/mL) and alpha-glucosidase (61.38 +/- 0.25 and 74.76 +/- 0.29 mu g/mL) respectively. Both extracts showed a remarkable improvement in the rate of glucose uptake into yeast cells. These findings indicate that A. parviflora leaf possesses antidiabetic and antioxidant properties which justify its traditional antidiabetic use. Based on our findings, we suggest that A. parviflora might be used as an effective phytopharmaceutical in the management of type II diabetes.