Farrerol Alleviates Cerebral Ischemia-Reperfusion Injury By Promoting Neuronal Survival And Reducing Neuroinflammation

Objective:Ischemia-reperfusion(I/R)injury is a key influencing factor in the outcome of stroke treatment to restore blood flow.Inflammatory response,oxidative stress,and neuronal apoptosis are among the main factors that affect the development of I/R injury.Farrerol(FAR)is a natural compound that can effectively inhibit the inflammatory response and oxidative stress.Here,we aimed to investigate the effect and mechanism of FAR on cerebral I/R injury.Methods:We made mice transient middle cerebral artery occlusion model(t MCAO)to assess the effects of FAR in vivo,made neurons and microglia glucose oxygen deprivation/reperfusion(OGD/R)model to assess the effects of FAR in vitro.Doppler flowmetry was used to verify the success of the animal model.The drug was administered by intraperitoneal injection.Modified Neurological severity score(m NSS)was used to assess mice neurological function.TTC staining was used to assess the infarct volume of brain after t MCAO;Immunofluorescence MAP2 staining and Nissl stating were used to detect neuronal death in brain after I/R.We used CCK8,and LDH assay to assess the effect of FAR on neuronal survival after OGD/R.ROS assay was used to measure the extent of oxidative stress.Immunofluorescence Iba-1 staining was used to detect neuronal number and measure dendritic axonal changes and morphology of microglia.At the molecular level,the expression of p-CREB,p-AKT,p-ERK,p-P65,p-JNK and β-actin was measured by western blotting(WB)and the m RNA transcript levels of CREB,BCL-2,BDNF and inflammatory factors were measured by quantitative real-time PCR(q RT-PCR).Results:1.FAR significantly reduced the infarct volume and improved motor performance after ischemic stroke.2.FAR reduced neuronal damage after cerebral ischemia-reperfusion in the in vivo.3.FAR treatment reduced the activation of microglia in brain after cerebral I/R and inhibited the neuroinflammatory response.4.FAR promotes neuronal survival after OGD/R in vitro.5.FAR enhanced CREB activation both in vivo and in vitro.6.FAR upregulated CREB transcript levels,which in turn increased the expression of neurotrophic factors and anti-apoptotic genes downstream of CREB,thereby promoting neuronal survival.7.FAR treatment reduced ROS production after OGD/R.8.FAR inhibit microglia activation by reducing phosphorylation of MAPK and NF-k B pathways,which in turn inhibited the activation of inflammatory responses.9.FAR-mediated attenuation of neuroinflammation directly promoted neuronal survival after OGD/R.Conclusion: These data revealed the protective effect of FAR on cerebral I/R injury,identified the CREB pathway as a novel target of FAR to promote neuronal survival after I/R,and confirmed that FAR also attenuated neuronal injury through the inhibition of neuroinflammation.Therefore,FAR could be a potentially effective drug for the treatment of cerebral I/R injury.