Free radical scavenging effect and oxidative stress protective activity of domestic processed Polygoni Multiflori Radix

Abstract

In this study, we confirmed biological compounds from methanol (MeOH) extract of processed Polygoni Multiflori Radix (PPMR), and the radical scavenging effect and oxidative stress protective activity of MeOH extract of PPMR were investigated under in vitro conditions using LLC-PK1 renal epithelial cells. In HPLC analysis, MeOH extract of PPMR contained four species of biological compounds named 2,3,5,4'-tetrahydroxystilbene 2-O-β-D-glucoside, emodin, chrysophanol, and rhein. 2,3,5,4'-Tetrahydroxystilbene 2-O-β-D-glucoside was detected as the main compound in PPMR as 115.02 mg/kg. MeOH extract of PPMR showed 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) diammonium salt (ABTS), and hydroxyl radical scavenging activities in a concentration- dependent manner. In particular, upon 50 μg/mL of PPMR extract treatment, DPPH, ABTS, and hydroxyl radical scavenging activities were approximately 48.4%, 57.9%, and 81.2%, respectively. LLC-PK1 cell viability declined in response to oxidative stress induced by pyrogallol, sodium nitroprusside (SNP), and morpholinosydnonimine (SIN-1) generators of NO, O2-, and ONOO-, respectively. However, MeOH extract of PPMR significantly and dose-dependently inhibited oxidative-stressed LLC-PK1 cell cytotoxicity. In fact, upon 50 μg/mL of PPMR extract treatment, LLC-PK1 cell viabilities were approximately 82.1%, 89.1%, and 77.6% compared to stress levels induced by pyrogallol, SNP, and SIN-1, respectively. ? 2015, Korean Society of Food Science and Nutrition. All rights reserved.