Table 1.

Mechanisms of H₂ in multiple systemic diseases.

Diseases	Effects of H2	Reference
Respiratory system	Regulates IL-2, IL-7, IL-10, and TNF-α	[66]
	Increases surfactant proteins	[11]
	Reverses EMT and increases E-cadherin	[68]
Cardiovascular system	Suppresses macrophage infiltration, TNF-α expression, and vascular aging	[88]
	Inhibits cardiomyocyte apoptosis	[39, 40]
	Decreases MDA, 8-OHdG, and IL-1β	[92, 93]
Nervous system	Reduces loss of dopaminergic neurons and improves nigrostriatal degeneration	[74, 75]
	Reduces neurological deficits and endothelial cell injury	[83, 84]
Digestive system	Induces HO-1 and Sirt1 expression	[98]
	Activates the A2A receptor-mediated PI3K-Akt pathway	[99]
	Inhibits bile acid oxidation	[114]
Reproductive system	Inhibits cell proliferation and improves SOD	[130]
	Improves serum levels of anti-Müllerian hormone	[133]
	Improves serum testosterone level	[135]
Urinary system	Increases Il-4 and Il-13 and promotes macrophage polarization to the M2 type	[140]
	Activates the Keap1/Nrf2 signaling pathway	[145]
	Prevents HK-2 cells from undergoing EMT
Motor system	Reduces blood lactate levels	[47]
	Suppresses serum 8-OHdG levels	[154]
Sensory system	Reduces wound area and levels of proinflammatory cytokines	[159]
	Improves auditory brainstem response	[161]
Metabolic syndrome	Decreases LDL and increases high-density lipoprotein	[148]
	Decreases glucose and insulin levels	[149]
	Stimulates energy metabolism	[152]
Cancer	Controls cancer progression and improves quality-of-life	[140]
	Reduces proportion of terminal PD-1+ CD8+ T cells	[37]