Molecular hydrogen inhibits lipopolysaccharide/interferon γ-induced nitric oxide production through modulation of signal transduction in macrophages

► Hydrogen inhibits LPS/IFNγ-induced NO release through suppressing iNOS expression. ► Hydrogen inhibits LPS/IFNγ-induced activation of ASK1 and its downstream signaling. ► Hydrogen does not affect LPS/IFNγ-induced NOX activation and ROS production. ► Hydrogen alleviates anti-type II collagen antibody-induced arthritis in mice. ► We provide the molecular basis for hydrogen effects on inflammation.