Hydrogen gas inhalation protects against liver ischemia/reperfusion injury by activating the NF-κB signaling pathway
Zhang CB, Tang YC, Xu XJ, Guo SX, Wang HZ. · Experimental and Therapeutic Medicine. 2015;9(6):2114-2120.
What kind of evidence is this?
Preclinical
Rat concentration/duration screening followed by syngeneic orthotopic liver-transplant comparisons
Critical care and ischemia-reperfusion
Inhaled H₂
Not reported in this record.
Not reported in this record.
Methods at a glance
Male Sprague-Dawley rats undergoing partial hepatic ischemia/reperfusion and syngeneic liver transplantation.
The three transplant-timing groups contained n=6 each. The article does not consolidate the sample size for every 1%, 2%, 3% and 1-, 3-, 6-hour screening group, so no larger total is inferred.
Screening exposure for 1, 3 or 6 hours immediately before 90-minute ischemia and 180-minute reperfusion; transplant tissues/blood were sampled over the first three postoperative hours.
Conscious rats received 1%, 2% or 3% H₂ mixed with air for 1, 3 or 6 hours immediately before ischemia/reperfusion; 2% for one hour was selected for donor/recipient transplant comparisons.
Inhaled H₂ mixed with air — not Brown's gas and not a co-generated H₂/O₂ mixture.
The source says the gas mixture was delivered through a pipeline at 1.5 mL/hour, but it does not clarify whether this is total-mixture or H₂-only flow. Because that rate is unusually low for the chamber arrangement, Hydrogenology preserves it as reported and does not derive H₂ or O₂ mL/min.
Not reliably determinable. The article prints 1.5 mL/hour (0.025 mL/min) for the pipeline but does not identify the denominator as total mixture versus H₂ flow.
Air was the carrier; O₂ concentration and O₂ mL/min were not separately reported and are not inferred.
Untreated I/R controls; concentration and duration groups; and donor-only, recipient-only, or donor-plus-recipient H₂ exposure around transplantation.
Outcomes and reported result
ALT, AST, IL-6, TNF-α, Egr-1, IL-1β, liver histology/ultrastructure, and NF-κB, HO-1, Bcl-2 and A20 expression.
All tested concentrations reduced ALT/AST versus control, with 2% presented as optimal; one hour was selected over longer exposures. The donor-only H₂ group had higher NF-κB/HO-1/Bcl-2/A20 expression than recipient-only or donor-plus-recipient groups. The article does not provide a complete table of every pairwise/null comparison or long-term graft outcomes.
The complete free PMC article was checked for concentration and duration screens, the source's ambiguous printed flow, I/R and transplant procedures, timing-group results and available outcome reporting.
A reported association, difference or mechanism is not automatically a clinical benefit. Null findings, outcome type, study design and precision all matter.
Cautions and applicability
Preclinical experiment with incomplete consolidated allocation for the screening phase, unusually/ambiguously reported gas flow, very short follow-up, surrogate biochemical endpoints and inconsistent mechanistic wording around NF-κB activation versus inhibition. No dedicated funding or conflict declaration was identified; absence is not inferred.
Rat hepatic I/R and transplantation; it does not establish a peri-transplant inhalation protocol or benefit in people.
Not reported in this record.
Not reported in this record.
Not reported in this record.
No single-study GRADE certainty rating is assigned. Certainty is assessed by important outcome across a complete eligible evidence set, not by attaching a final grade to one source.
Sources and record status
PMID: 26136944 · DOI: 10.3892/etm.2015.2385
Free full article in PubMed Central.
Complete PMC article and PubMed metadata; full-text extraction checked 9 August 2026.
2026-08-10