Antioxidant and α-glucosidase inhibitory properties of Carpesium abrotanoides L.

Abstract

Hyperglycemia causes oxidative stress, which further exacerbates the progression of diabetes mellitus and its complications. The aim of the present study was to evaluate the antidiabetic and antioxidant properties of the 80% methanolic extract of the aerial parts of Carpesium abrotanoides L. (CAME) through various in vitromodels. The extract exhibited potent α-glucosidase inhibitory activity with IC50value of 44.22 µg/ml. Kinetic studies revealed non-competitive inhibition of CAME on α-glucosidase enzyme. The antioxidant activities of CAME, measured in terms of IC50 values using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), ferrous ion chelating (FIC) and nitric oxide scavenging (NOS) were 111.2, 15.6, 150.2 and 798.5 µg/ml, respectively. CAME also showed significant reducing capability by ferric reducing antioxidant power (FRAP) assay. Inhibition of lipid peroxidation in CAME was found to be dose-dependent. It possessed considerable amounts of phenolics (88 mg gallic acid equivalent/g of extract) and flavonoids (12 mg quercetin equivalent/g of extract). Based on its strong α-glucosidase inhibitory and antioxidant activities, CAME appears to be a potential herb for the treatment of diabetes and can be further explored as a functional medicinal plant for isolating the active ingredient(s) along with animal studies in vivo.   Key words: Carpesium abrotanoides L., phenolic compounds, flavonoid compounds, α-glucosidase, ferric reducing antioxidant power, antioxidant, free radical.