Acetaminophen-　(APAP-)　induced　hepatic　injury　is　an　important　clinical　challenge.　Oxidative　stress,　inflammation,　apoptosis,　and　endoplasmic　reticulum　stress　(ERS)　contribute　to　the　pathogenesis.　Methane　has　potential　anti-inflammatory,　antioxidant,　and　antiapoptotic　properties.　This　project　was　aimed　at　studying　the　protective　effects　and　relative　mechanisms　of　methane　in　APAP-induced　liver　injury.　In　the　in　vivo　experiment,　C57BL/6　mice　were　treated　with　APAP　(400　mg/kg)　to　induce　hepatic　injury　followed　by　methane-rich　saline　(MRS)　10　ml/kg　i.p.　after　12　and　24　h.　We　observed　that　MRS　alleviated　the　histopathological　lesions　in　the　liver,　decreased　serum　aminotransferase　levels,　reduced　the　levels　of　inflammatory　cytokines,　suppressed　the　nuclear　factor-κB　expression.　Further,　we　found　that　MRS　relieved　oxidative　stress　by　regulating　the　Nrf2/HO-1/NQO1　signaling　pathway　and　their　downstream　products　after　APAP　challenge.　MRS　also　regulated　proteins　associated　with　ERS-induced　apoptosis.　In　the　in　vitro　experiment,　the　L-02　cell　line　was　treated　with　APAP　(10　mM)　to　induce　hepatic　injury.　We　found　that　a　methane-rich　medium　decreased　the　levels　of　reactive　oxygen　species　(DHE　fluorescent　staining),　inhibited　apoptosis　(cell　flow　test),　and　regulated　the　Nrf2/HO-1/NQO1　signaling　pathway.　Our　data　indicated　that　MRS　prevented　APAP-induced　hepatic　injury　via　anti-inflammatory,　antioxidant,　anti-ERS,　and　antiapoptotic　properties　involving　the　Nrf2/HO-1/NQO1　signaling　pathway.　©　2019　Yang　Feng　et　al.