title: Hydrogen from intestinal bacteria is protective for Concanavalin A-induced hepatitis.
abstract: It is well known that some intestinal bacteria, such as Escherichia coli, can produce a remarkable amount of molecular hydrogen (H(2)). Although the antioxidant effects of H(2) are well documented, the present study examined whether H(2) released from intestinally colonized bacteria could affect Concanavalin A (ConA)-induced mouse hepatitis. Systemic antibiotics significantly decreased the level of H(2) in both liver and intestines along with suppression of intestinal bacteria. As determined by the levels of AST, ALT, TNF-alpha and IFN-gamma in serum, suppression of intestinal bacterial flora by antibiotics increased the severity of ConA-induced hepatitis, while reconstitution of intestinal flora with H(2)-producing E. coli, but not H(2)-deficient mutant E. coli, down-regulated the ConA-induced liver inflammation. Furthermore, in vitro production of both TNF-alpha and IFN-gamma by ConA-stimulated spleen lymphocytes was significantly inhibited by the introduction of H(2). These results indicate that H(2) released from intestinal bacteria can suppress inflammation induced in liver by ConA.
authors.affiliation: Department of Immunology, The Forsyth Institute, Boston, MA, USA.
authors.forename: Mikihito
authors.initials: M
authors.lastname: Kajiya
authors.forename: Kimihiro
authors.initials: K
authors.lastname: Sato
authors.forename: Marcelo J B
authors.initials: MJ
authors.lastname: Silva
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Ouhara
authors.forename: Phi M
authors.initials: PM
authors.lastname: Do
authors.forename: K T
authors.initials: KT
authors.lastname: Shanmugam
authors.forename: Toshihisa
authors.initials: T
authors.lastname: Kawai
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000032:analysis; D056486:Chemical and Drug Induced Liver Injury / Q000473:pathology / Q000517:prevention & control*; D003208:Concanavalin A / Q000633:toxicity; D004195:Disease Models, Animal; D004926:Escherichia coli / Q000378:metabolism*; D006859:Hydrogen / Q000378:metabolism*; D007422:Intestines / Q000382:microbiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008934:Mitogens / Q000633:toxicity
chemical_list: D015415:Biomarkers; D008934:Mitogens; D003208:Concanavalin A; D006859:Hydrogen