Hydrogen-rich water achieves cytoprotection from oxidative stress injury in human gingival fibroblasts in culture or 3D-tissue equivalents, and wound-healing promotion, together with ROS-scavenging and relief from glutathione diminishment

Abstract:

The aim of the present study is to investigate protective effects of hydrogen-rich water (HW) against reactive oxygen species (ROS)-induced cellular harmful events and cell death in human gingival fibroblasts (HGF) and three-dimensional (3D-) gingival tissue equivalents. HW was prepared with a magnesium stick in 600-mL double distilled water (DDW) overnight. Dissolved hydrogen was about 1460 ± 50 μg/L versus approximately 1600 μg/L for the saturated hydrogen. Under cell-free conditions, HW, dose-dependently, significantly scavenged peroxyl radicals (ROO·) derived from 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH). Extract from HW-treated HGF cells scavenged ROO· more markedly than that from DDW-treated cells, suggesting that HW can increase the intracellular antioxidant capacity. Hydrogen peroxide dose-dependently increased the intracellular ROS generation, which was significantly repressed by HW, both in the cytoplasm and nuclei. LIVE/DEAD staining and our original cell viability dye-extraction assay showed that HW significantly protected HGF cells from hydrogen peroxide-induced cell death. Hydrogen peroxide also diminished the contents of intracellular glutathione, which were appreciably relieved by HW-pretreatment. Additionally, HW noticeably prevented cumene hydroperoxide-induced generation of cellular ROS in epidermis parts of 3D-gingival equivalents. The in vitro scratch assay showed that HW was able to diminish physical injury-induced ROS generation and promote wound healing in HGF cell monolayer sheets. In summary, HW was able to increase intracellular antioxidative capacity and to protect cells and tissue from oxidative damage. Thus, HW might be used for prevention/treatment of oxidative stress-related diseases.