Advances in Normobaric Hyperoxia Brain Protection in Experimental Stroke

Abstract

As we all know that stroke is still a leading cause of death and acquired disability. Etiological treatment and brain protection are equally important. This review aimed to summarize the advance of normobaric-hyperoxia (NBHO) on brain protection in the setting of experimental stroke and brain trauma. We analyzed the data from relevant studies published on PubMed Central (PMC) and EMBASE, about NBHO on brain protection in the setting of experimental ischemic and hemorrhagic strokes and brain trauma, which revealed that NBHO had important value on improving hypoxia and attenuating ischemia damage. The mechanisms of NBHO involved increasing the content of oxygen in brain tissues, restoring the function of mitochondria, enhancing the metabolism of neurons, alleviating blood-brain barrier (BBB) damage, weakening brain cell edema, reducing intracranial pressure, and improving cerebral blood flow, especially in the surrounding of injured area of the brain, to make the neurons in penumbral area alive. Compared to hyperbaric oxygen (HBO), NBHO is more safe and more easily to transform to clinical use, whereby, further studies about the safety and efficacy as well as the proper treatment protocol of NBHO on human may be still needed.

Implications of Hyperoxia over the Tumor Microenvironment: An Overview Highlighting the Importance of the Immune System

“…As opposed to HBO, normobaric oxygen therapy (NBO) is high oxygen administration at normal pressure [ 35 ]. Despite both therapies diminishing hypoxic regions, at high pressures, it is possible to reach better oxygenation of the tumor [ 36 , 37 ].…”

An overview of hyperbaric oxygen preconditioning against ischemic stroke

“…The author believed that this may be the reason why TEER in the HBO-PC group was higher than that in the hypoxia group. Chen et al found that hyperoxia could reduce damage to the BBB, attenuate brain cell edema, lower intracranial pressure, improve cerebral blood flow, especially around areas of brain damage, and activate neurons in hemispheric areas(Chen et al 2020 ). These results demonstrated that HBO has the potential to protect the integrity of the BBB but need to be further validated.…”

Exploiting moderate hypoxia to benefit patients with brain disease: Molecular mechanisms and translational research in progress

“…84 Advances in normobaric hyperoxia application, particularly derived from animal studies evaluating effects in experimental stroke and brain trauma, have recently been reviewed. 85 While normobaric hyperoxia is commonly used in the settings mentioned above, the use of hyperbaric O 2 therapy seems to be more effective in other circumstances, for example, acute severe traumatic brain injury, 86 or carbon monoxide poisoning. 87 Noteworthy in this context, in severe burns, beneficial effects of hyperbaric O 2 therapy may include the attenuation of central sensitization.…”

“…96,98,99 Moreover, underlying molecular mechanisms include variable changes in the expression of caspase-3, matrix metalloproteinase-9, aquaporin-4, and Na+/H+ exchanger-1. 85,100,101 On the other hand, contrasting effects of hypoxia versus hyperoxia were found, for example, in a mouse model of Friedreich's ataxia where breathing of 11% O 2 attenuated the progression of ataxia, whereas breathing 55% O 2 hastened it. 102 Effects of hypoxia versus hyperoxia on gene expression and functional or structural neuroplasticity have not been studied yet systematically and back-to-back.…”