Hydrogen inhibits microglial activation and regulates microglial phenotype in a mouse middle-cerebral-artery-occlusion model
Huang JL et al. · Med Gas Res. 2019;9(3):144–150.
What kind of evidence is this?
Preclinical
Blinded controlled mouse focal-cerebral-ischemia-reperfusion experiment
Other neurological conditions
Inhaled H₂
Not reported in this record.
Not reported in this record.
Methods at a glance
80 male C57BL mice after one-hour middle-cerebral-artery occlusion
80 mice divided among sham, ischemia-reperfusion, oxyhydrogen and nitrogen/oxygen-control groups
90 minutes; outcomes 23 hours after reperfusion
High-concentration oxyhydrogen inhalation for 90 minutes starting immediately after reperfusion
Brown’s gas / oxyhydrogen — H₂ and O₂ co-delivered in an approximately 2:1 ratio.
66.7% H₂ with 33.3% O₂ balance.
Not reported — gas percentages are given, but H₂ flow in mL/min is not.
Approximately 33.3% O₂ was co-delivered; O₂ flow in mL/min was not reported.
Nitrogen/oxygen mixture with H₂ replaced by N₂, plus ischemia and sham groups
Outcomes and reported result
Infarct, edema, neurological deficits, microglial activation, inflammatory genes and M1/M2 polarization
The article reports smaller brain injury, improved neurological scores and microglial changes interpreted as reduced activation and greater M2 polarization with oxyhydrogen.
Gas composition, allocation, methods, principal results and ethics information checked in the open-access full text.
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 mouse stroke model with short follow-up and a very high H₂/O₂ mixture. Concentration does not provide absolute H₂ or O₂ flow.
Focal cerebral ischemia-reperfusion in mice.
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: 31552875 · DOI: 10.4103/2045-9912.266987
Open-access full text is available through PMC.
Open-access PMC full text and PubMed record.
2026-08-10