Efficacy of a hydrogen–oxygen generator in treating cigarette smoke–induced chronic obstructive pulmonary disease in rats
Huang WT, Cheng TJ, Huang LH, Hou YT. · Current Research in Toxicology. 2025;8:100214.
What kind of evidence is this?
Preclinical
Randomized cigarette-smoke rat model with natural-recovery and nebulized-steroid comparators
Respiratory health
Inhaled H₂
Not reported in this record.
Not reported in this record.
Methods at a glance
Male Sprague-Dawley rats exposed to cigarette smoke daily for three months, then followed during three months of treatment or recovery.
Initial smoke phase reported smoke n=9 and control n=5. Post-treatment outcome groups were very small and varied by assay; the principal BALF comparison used H₂/O₂ n=2, natural recovery n=3, steroid n=3 and control n=3.
Three months of smoke exposure, followed by two hours/day H₂/O₂ for three additional months.
Two-hour whole-chamber exposure every day for three months after cigarette-smoke exposure.
Brown's gas / oxyhydrogen generated at approximately 66% H₂ and 33% O₂.
The generator explicitly produced 1,000 cc/min H₂ and 500 cc/min O₂; the chamber atmosphere was reported as approximately 66% H₂ and 33% O₂.
1,000 mL/min.
500 mL/min.
Non-smoking controls, cigarette-smoke with three months of natural recovery, and cigarette-smoke with nebulized triamcinolone 1 mg/kg/day.
Outcomes and reported result
BALF leukocyte subsets, body/food/water measures, lung histology, mean linear intercept, mean alveolar number and tricuspid-annular-plane systolic excursion.
Several inflammatory-cell, alveolar-morphology and TAPSE comparisons favored H₂/O₂ over natural recovery or steroid. Some natural-recovery measures also improved. No significant MLI or MAN differences were reported between H₂/O₂-treated smoke animals and non-smoking controls, but these analyses used extremely small groups.
The complete free PMC article, figures and group descriptions were checked for smoke and treatment protocols, exact generator flows, outcome-specific samples, natural-recovery findings, limitations, funding and conflicts.
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
Single experiment with post-treatment groups as small as n=2, shifting group denominators across phases, multiple comparisons, incomplete standardization of the COPD model and three-month high-concentration chamber exposure. Taiwan public funding and technical support from North-vision Tech were reported; one author was affiliated with North-vision, the generator manufacturer, while authors declared no competing interests.
Cigarette-smoke injury in rats; it does not establish efficacy or safety for people with COPD.
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: 39839142 · DOI: 10.1016/j.crtox.2024.100214
Free full article in PubMed Central.
Complete PMC article and PubMed metadata; full-text extraction checked 9 August 2026.
2026-08-10