Hydrogen-rich water protects against liver injury in nonalcoholic steatohepatitis through HO-1 enhancement via IL-10 and Sirt 1 signaling

Abstract

Nonalcoholic steatohepatitis (NASH) could progress to hepatic fibrosis in the absence of effective control. The purpose of our experiment was to investigate the protective effect of drinking water with a high concentration of hydrogen, namely, hydrogen-rich water (HRW), on mice with nonalcoholic fatty liver disease to elucidate the mechanism underlying the therapeutic action of molecular hydrogen. The chol-ine-supplemented, L-amino acid-defined (CSAA) or the choline-deficient, L-amino acid-defined (CDAA) diet for 20wk was used to induce NASH and fibrosis in the mice model and simultaneously treated with the high-concentration 7-ppm HRW for different periods (4 wk, 8 wk, and 20wk). Primary hepatocytes were stimulated by palmitate to mimic liver lipid metabolism during fatty liver formation. Primary he-patocytes were cultured in a closed vessel filled with 21% O2 þ 5% CO2 þ 3.8% H2 and N2 as the base gas to verify the response of primary hepatocytes in a high concentration of hydrogen gas in vitro. Mice in the CSAA þ HRW group had lower serum levels of ala-nine aminotransferase (ALT) and aspartate aminotransferase (AST) and milder histological damage. The inflammatory cytokines were expressed at lower levels in the HRW group than in the CSAA group. Importantly, HRW reversed hepatocyte fatty acid oxidation and lipo-genesis as well as hepatic inflammation and fibrosis in preexisting hepatic fibrosis specimens. Molecular hydrogen inhibits the lipopoly-saccharide-induced production of inflammation cytokines through increasing heme oxygenase-1 (HO-1) expression. Furthermore, HRW improved hepatic steatosis in the CSAA þ HRW group. Sirtuin 1 (Sirt1) induction by molecular hydrogen via the HO-1/adenosine mono-phosphate activated protein kinase (AMPK)/peroxisome proliferator-activated receptor a (PPARa)/peroxisome proliferator-activated recep-tor c (PPAR-c) pathway suppresses palmitate-mediated abnormal fat metabolism. Orally administered HRW suppressed steatosis induced by CSAA and attenuated fibrosis induced by CDAA, possibly by reducing oxidative stress and the inflammation response. NEW & NOTEWORTHY The mRNA expression of inflammatory cytokines in the HRW group was lower than in the CSAA group. HRW reversed hepatocyte apoptosis as well as hepatic inflammation and fibrosis in NASH specimens. Molecular hydrogen inhib-its LPS-induced inflammation via an HO-1/interleukin 10 (IL-10)-independent pathway. HRW improved hepatic steatosis in the CSAA þ HRW group. Sirt1 induction by molecular hydrogen via the HO-1/AMPK/PPARa/PPARc pathway suppresses palmitate-mediated abnormal fat metabolism. fatty liver; fibrosis; heme oxygenase-1; hydrogen-rich water; sirtuin 1

Study details

Article type

Original Research

Disease / injury model

Nonalcoholic steatohepatitis (NASH) and liver fibrosis induced by choline-deficient or choline-supplemented amino acid-defined diets in mice

Duration

20 weeks

Dose comparison

Different durations of HRW administration (4, 8, 20 weeks) were compared, and in vitro hydrogen gas concentration (3.8%) was used to assess dose-dependent effects on cells.

Dose-dependent effect

Yes

Outcome

Positive

Findings

Hydrogen-rich water (HRW) significantly protected against liver injury in a mouse model of nonalcoholic steatohepatitis (NASH) and fibrosis, reducing serum ALT/AST, hepatic inflammation, oxidative stress, and fibrosis. HRW upregulated HO-1, IL-10, and Sirt1, suppressed inflammatory cytokines, and improved lipid metabolism via the HO-1/AMPK/PPARa/PPARc pathway.