Figure 1.

Potential mechanisms of HBO therapy.

Note: Many of the pathways work parallel, or together, to induce neuroprotection in the brain. These mechanisms include: increasing tissue oxygenation, reducing inflammation, inhibiting apoptosis, reducing ICP, and promoting neurogenesis and angiogenesis. HBO: Hyperbaric oxygen; ICP: intracranial pressure; CBF: cerebral blood flow; CSF: cerebrospinal fluid; pO₂: partial pressure of oxygen; IL-8: interleukin-8; IL-10: interleukin-10; TNF-α: tumor necrosis factor-α; MMP-9: matrix metalloproteinase-9; mPTP: mitochondrial permeability transition pore; Cas-3: caspase-3; HIFs: hypoxia-inducible factors; CREB: cAMP response element-binding; Nrf2: nuclear factor (erythroid-derived 2)-like 2; HO-1: heme oxygenase-1; TLR4: Toll-like receptor 4; NF-κB: nuclear factor-kappaB.