Antioxidant and Cytoprotective Effects of Oligomeric and Polymeric Procyanidin Fractions from Defatted Grape Seed in PC12 Cells

Abstract

In this study, a crude polyphenol extract (CPE) from defatted grape seeds was evaluated for antioxidant and cytoprotective effects in PC12 cells. The CPE was then fractionated into a catechin and oligomeric procyanidin fraction (F_cat+olig) and a polymeric procyanidin fraction (F_pol), and the bioactivities of the fractions were evaluated individually. F_pol was the richest in total polyphenol, total flavonoid, and polymeric procyanidin but contained less flavan-3-ol than F_cat+olig. Consistent with these results, F_pol had the highest 2,2-diphenyl-β-picrylhydrazyl radical scavenging activity and reducing power. Both F_cat+olig and F_pol had higher 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic) acid radical scavenging activity than CPE. The resistance of PC12 cells against oxidative stress, after pretreatment with F_pol (200 μg/mL) for 9 h, was 100.7±2.9% of that in the control. Moreover, pretreating these cells with F_cat+olig and F_pol significantly decreased reactive oxygen species generation. These results provide information on a potential new source of antioxidants in the form of a functional food derived from an agricultural by-product.