Protective effect of procyanidin B2 on hydrogen peroxide (H2O2)-induced oxidative damage in MCF-7 cells

Abstract

AbstractThe aim of this study is to assess the cytoprotection and potential molecular mechanisms of procyanidin B2 (PCB2) on hydrogen peroxide (H2O2)-induced oxidative damage in MCF-7 cells. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed to determine the viability of MCF-7 cell exposure to H2O2 or PCB2. We measured the antioxidant properties of PCB2 by determining the activities of SOD, GSH-Px, LDH and MDA levels, and evaluated apoptosis and intracellular reactive oxygen species (ROS) levels. The related proteins expression levels were monitored by Western blot. MCF-7 cells induced with H2O2 had a remarkable decrease in cell viability that was suppressed when it was interfered with PCB2 (0.1–10.0 μM). PCB2 interference memorably and dose-dependently inhibited H2O2-induced LDH leakage, ROS and MDA overproduction, while PCB2 markedly increased H2O2-induced the activities of SOD and GSH-Px. Eventually, H2O2 prominently down-regulated the ratio of Bcl-2/Bax and the relative proteins expression levels of Nrf2, GCLC, NQO1 and HO-1, and up-regulated the relative proteins expression levels of cytochrome c, caspase-3 and Keap1. However, the relative expression levels of these proteins were reversed in PCB2-interfered MCF-7 cells. This study implied that protective effect of PCB2 on H2O2-induced oxidative damage in MCF-7 cells might be related to inhibition of mitochondria-dependent apoptosis, activation of Keap1/Nrf2/HO-1 signaling pathway and improvement of the antioxidant enzymes activities.