Gastrodin injection relieves hypoxic-ischemic brain injury in newborn rats by regulating the P62/Nrf2/HO-1 pathway

Hypoxic-ischemic encephalopathy (HIE) is the leading cause of death and disability in newborns. Hypothermia treatment (TH) is currently the only method that can improve the survival rate of HIE patients, but it has many limitations. Previous studies have shown that gastrodin injection has a potential neuroprotective effect on brain injury. However, it is unclear whether it has the same effect on HIE and its mechanism of action. This study investigated the neuroprotective effect of gastrodin injection on HIE and its possible mechanism through in vivo and in vitro experiments. For in vivo experiments, a hypoxic-ischemic brain damage (HIBD) model was established in neonatal rats, and immediately after modeling, a transperitoneal injection of gastrodin injection was administered. The model was verified via laser diffuse imaging, and hematoxylin-eosin (H&E), Nissl's staining, and 2,3,5-triphenyltetrazolium chloride (TTC) staining were performed to assess the brain tissue damage and the area of brain infarction, and short- and long-term neurobehavioral assessments were performed. Brain tissue damage, cerebral infarction area, short-term and long-term neurobehavioral assessment, superoxide dismutase (SOD), malondialdehyde (MDA), glutathione (GSH-PX), and catalase (CAT) detection, Western blotting and ELISA were used to analyze the levels of oxidative stress and inflammatory factors in brain tissue. For in vitro experiments, a hypoxia-glucose deprivation/reperfusion (OGD/R) injury model was established in SH-SY5Y cells, and gastrodin injection was injected immediately after model establishment. To determine the mechanism of action of gastrodin injection, XRK3F2, a specific inhibitor of P62, was used, and cell viability, the level of intracellular reactive oxygen species (ROS), the mitochondrial membrane potential, and oxidative stress-related protein levels were measured to further validate the neuroprotective effect of gastrodin injection. The results showed that gastrodin injection could alleviate the area of cerebral infarction, reduce neuronal oxidative stress injury, improve short-term and long-term neurobehavioral deficits, improve mitochondrial function, improve the body's ability to resist oxidative stress, and reduce inflammatory reactions in brain tissues from HIBD rats. In vitro experiments revealed that gastrodin injection increased neuronal cell survival after OGD/R injury and inhibited the occurrence of oxidative stress and apoptosis; however, these neuroprotective effects were attenuated by XRK3F2, a specific inhibitor of P62. The present study suggested that gastrodin injection may attenuate oxidative stress injury and apoptosis and ameliorate brain injury after HBID by activating the P62/Nrf2/HO-1 signaling pathway.