Hypoxic-ischemic brain injuries (HHI) are the third leading cause of death in the United States. HHI to the brain is not just a significant cause of death, it can also cause neurologic disability. These brain injuries impact over half a million new victims annually. Of these victims, approximately one-third will die and another third will be left with a permanent severe disability.
The severity of disability is not predicted by the amount of brain tissue loss. For example, damage to a small area in the medial temporal lobe may cause severe disability including loss of speech, while wider damage elsewhere has less impact on function. In the brain, populations of cells located side by side can display dramatically different vulnerabilities.
Hypoxic ischemic injuries are often induced by:
Hypoxia happens when tissues (particularly organs like the brain) are impacted by oxygen deficiency. Ischemia occurs when there is not enough blood supply to major organs such as the heart and brain. Cytotoxicity occurs when certain chemicals or mediator cells (like immune cells) kill living, healthy cells.
Hypoxic ischemic brain injury can have many causes, including:
Birth asphyxia causes 23% of all neonatal deaths worldwide. That is 840,000 newborns a year. A preclinical study looked at whether CBD neuroprotection is sustained over a prolonged period. Newborn Wistar rats underwent HI injury (10% oxygen for 120 min after left carotid artery electrocoagulation) and then received vehicle (HV, n ¼ 22) or 1 mg/kg CBD (HC, n ¼ 23). Sham animals were similarly treated (SV, n ¼ 16 and SC, n ¼ 16). Animal preclinical studies are not reliable for human health effects but it can give us a sense of chemical reactions and plausibility. The extent of brain damage in the rats was determined by:
Several neurobehavioral tests (RotaRod, cylinder rear test[CRT] and novel object recognition[NOR]) were carried out 30 days after HI (P37). CBD modulated brain excitotoxicity, oxidative stress, and inflammation remained seven days after HI. Excitotoxicity is when our nerve cells are killed by overstimulation from neurotransmitters. Oxidative stress is when there is a bodily imbalance between free radicals and antioxidants. Free radicals are molecules that contain oxygen with an uneven number of electrons.
Free radicals can help fight off pathogens. Pathogens lead to infections. When managed through antioxidants free radicals play an important role in health. When there are not enough antioxidants to balance out the free radicals the free radicals start damaging our:
Scientists were able to stop cell die off.
We observed that HI led to long-lasting functional impairment, as observed in all neurobehavioral tests at P37, whereas the results of HC animals were similar to those of sham animals (all p < 0.05 vs. HV). CBD reduced brain infarction volume by 17% and lessened the extent of the histological damage. CBD lessened brain damage in rat models. No differences were observed between the SV and SC groups in any of the experiments. Therefore, CBD administration after HI injury to newborn rats led to long-lasting neuroprotection with the overall effect of promoting greater functional rather than histological recovery. These effects of CBD were not associated with any side effects. These results push forward the medical interest in CBD as a neuroprotective agent for neonatal hypoxic-ischemic injury.