Antioxidant Activities of Extracts from Sarcocarp of<i> Cotoneaster multiflorus</i>

Abstract

The ethanol-water (7 : 3, v/v) extract of Cotoneaster multiflorus sarcocarp was sequentially fractionated by liquid-liquid partition using <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mrow><mml:mi>n</mml:mi></mml:mrow></mml:math>-hexane, diethyl ether, methylene dichloride, and ethyl acetate. The contents of total polyphenols, total flavones, and oligomeric proanthocyanidins in the five parts (including the ethanol-water extract) were determined. In addition, 2,2-diphenyl-1-picrylhydrazyl free radical-scavenging, 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt radical cation decolorization, reducing power, ferric reducing antioxidant power, and lipid peroxidation inhibition assays were conducted to test the antioxidant activities of Sample 1 (the ethanol-water fraction) and Sample 2 (the ethyl acetate fraction) in vitro . In the above five assays, Sample 2 showed greater antioxidant capacities than Sample 1. Furthermore, Sample 2 was better able to protect low-density lipoproteins from oxidation in a dose-dependent manner. The test results show that C. multiflorus sarcocarp, especially the ethyl acetate-soluble fraction, may be a potential source of natural antioxidants.