Antioxidant and α-glucosidase inhibitory effects of ethanolic extract of Ainsliaea acerifolia and organic solvent-soluble fractions

Among the naturally occurring antioxidants, polyphenols are widely distributed in various fruits, vegetables, wines, juices, and plant-based dietary sources and divided into several subclasses that included phenolic acid, flavonoids, stilbenes, and lignans. As part of our continuing search for bioactive food ingredients, the antioxidant and -glucosidase inhibitory activities of the aqueous ethanolic extract from the aerial parts of Ainsliaea acerifolia were investigated in vitro. The antioxidant properties were evaluated via radical scavenging assays using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2`-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) () radicals. In addition, the anti-diabetic effect of A. acerifolia extracts was tested via -glucosidase inhibitory assay. Furthermore, the total phenolic contents were determined using a spectrophotometric method. All the tested samples showed dose-dependent radical scavenging and -glucosidase inhibitory activities. In particularly, the -glucosidase inhibitory and radical scavenging properties of the ethyl acetate (EtOAc)-soluble portion from the aerial parts of the A. acerifolia were higher than those of the other solvent-soluble portions. These results suggest that A. acerifolia could be considered a new potential source of natural antioxidants and antidiabetic ingredients. More systematic investigation of the aerial parts of A. acerifolia will be performed for the further development of anti-oxidative and antidiabetic drugs.