Molecular hydrogen suppresses Porphyromonas gingivalis lipopolysaccharide-induced increases in interleukin-1 alpha and interleukin-6 secretion in human gingival cells

Periodontitis is defined as a multifactorial polymicrobial infection accompanied by inflammatory reactions. Porphyromonas gingivalis ( Pg ) is known as a major pathogen in the initiation and progression of periodontitis, and a major virulence factor is Pg lipopolysaccharide (LPS). Molecular hydrogen (H 2 ) has been reported to act as a gaseous antioxidant, which suppresses periodontitis progression by decreasing gingival oxidative stress. However, no human periodontitis model has examined the anti-inflammatory effects of H 2 . In this study, we examined the effects of H 2 on Pg LPS-induced secretion of 8 types of inflammation markers in a human periodontitis model using human gingival cells with enzyme-linked immunosorbent assays. Our results demonstrated that Pg LPS increased interleukin (IL) 1 alpha (IL-1α) and IL-6 secretion, but H 2 significantly suppressed the secretion of both cytokines without cytotoxicity. H 2 can suppress the production of IL-1α and IL-6, which are identified as cytokines involved in inflammatory reactions in periodontal disease. Thus, H 2 may provide therapeutic applications for periodontitis.