The protective effect of genistein postconditioning on hypoxia/reoxygenation-induced injury in human gastric epithelial cells

Abstract

Aim:

The aim of this study was to investigate the protective effect of genistein postconditioning on hypoxia/reoxygenation-induced injury in human gastric epithelial cells and to begin a tentative discussion on the mechanism behind this protection.

Methods:

A model of hypoxia/reoxygenation-induced injury was established in the human gastric epithelial cell line (GES-1). All cells in our present study were randomly divided into five groups: a normal control group (N), a hypoxia/reoxygenation group (H/R), a genistein postconditioning group (GP), a capsazepine+genistein postconditioning group (C+GP) and a DMSO vehicle postconditioning group (DM). The methods used included MTT assays to test cell viability, flow cytometric analyses to quantify the percentage of cell apoptosis, Western blot analyses to measure the protein expression of calcitonin gene-related peptide (CGRP), Bcl-2, and Bax, and immunocytochemistry assays to detect the expression of CGRP in each group.

Results:

The MTT assays indicated that the cell viabilities of the groups were 100.0%±0%, 51.4%±4.1%, 66.7%±2.0%, 56.1%±2.8%, and 50.7%±2.4%, respectively. Compared with the H/R group, the viability of the GP group was significantly increased ( P<0.01). Flow cytometric analysis showed that the cell apoptosis percentage of each group was 2.28%±0.44%, 12.17%±2.15%, 5.40%±1.22%, 10.43%±1.37%, and 11.02%±2.19%, respectively. Western blot analysis demonstrated that CGRP, Bcl-2, and Bax were expressed in normal human gastric epithelial cells. Compared with the H/R group, the GP group exhibited increased expression of CGRP and Bcl-2 and decreased expression of Bax. Immunocytochemistry assays indicated that the number of CGRP-positive cells in the GP group was significantly increased.

Conclusion:

Genistein postconditioning has a protective effect on hypoxia/reoxygenation-induced injury in human gastric epithelial cells. The mechanism by which genistein exerts this protection may be via activation of cellular vanilloid receptor subtype 1, resulting in the generation of an endogenous protection substance, CGRP.