Protective Effects Of Oligomeric Proantho Cyanidins On Early Brain Injury Following Subarachnoid Hemorrhage In Rats

[BACKGROUND]Subarachnoid hemorrhage is a common clinical critical nerve vascular diseases,accounted for about 5%of stroke.Subarachnoid hemorrhage is a complex neurosurgical disease,which is frequently associated with many complications.One of the most important include delayed cerebral vasospasm and early brain injury(EBI).Through decades of treatment and research on the delayed vasospasm,little success has been achieved in improving outcome following SAH.These findings have finally brought our focus on the influence of early brain injury after SAH.The mechanism of early brain injury is complex,including multiple pathophysiological changes,such as vascular lesions,brain edema,inflammatory reaction,of cell death and oxidative stress.The research of EBI after SAH has a broad prospect.The proanthocyanidins are condensed tannins,which are widely distributed in the plant kingdom.According to the different structural unit and the size of condensation degree,usually the dimer to tetramer were said oligomeric proantho cyanidins(OPC),the five dimer and above called polymeric procyanidins.The proanthocyanidins have strong antioxidant capacity,scavenging free radicals and the special effects of improving the body circulation.The ability of scavenging free radicals is related to the polymerization of molecular structure.The oligomers are easy to dissolve in water and absorbed by the body,so they are the most important one.In particular,the antioxidant activity of the dimer is the strongest.A large number of studies show that the proanthocyanidins also have many physiological protective functions,such as cardiovascular protection,anti ischemic reperfusion injury,immune regulation,anti atherosclerosis and anti platelet aggregation.Therefore,it could be possible to attenuate early brain injury after SAH.[OBJECTIVE]OPC has a strong antioxidant,such as scavenging free radicals,improving the special effect of fluid circulation.Oxidative stress reactions play an important role in the development of EBI after SAH,affecting the prognosis of patients.The experimental study explored the effects of OPC on EBI after SAH from the cellular level,organization level and animal level.[METHODS](1)Established the SAH model in rats by using a modified prechiasmatic blood injection.(2)SD rats were randomly divided into Control group,SAH+NS(normal saline)group,OPC low dose group(50 g/kg),medium dose group(100 g/kg),high dose group(200 g/kg).NS and OPC were injected into the lateral ventricles of the brain by 30min after opration.(3)24h after opartion,we evaluated the neurological function,brain edema,Western blot analysis of inflammatory and apoptotic proteins.At the same time,histological and biochemical changes were tested.[RESULTS](1)OPC treatment group significantly reduced the expression of ROS and MDA in the cortex of rats after SAH injury,and can improve the expression of SOD and GSH,so as to reduce the damage of oxidative stress.The protective effect of OPC 100 g/kg dose group was more obvious.(2)Compared with SAH+NS group,The neurological deficit and brain edema of rats after OPC treatment were improved.(3)After the intervention of OPC,positive apoptotic cells and the expression of Caspase-3 in temporal lobe cortex of rats decreased significantly,and at the same time,the protective protein expression of Bcl-2 was increased,showing that OPC can lighten the apoptosis after SAH.The neuroprotective effect of SAH+100 ?g/kg OPC group was stronger than the other two dose groups.(4)SAH,MPO and VCAM-1 were significantly increased in the cortex of temporal lobe of rats,and the inflammatory reaction was induced.OPC treatment can significantly reduce the level of inflammatory cytokines.The effect of SAH+100?g/kg OPC group was better than the other two groups.[CONCLUSION]Through the experimental research,we draw the following conclusions:antioxidant capacity of Oligomeric Proanthocyanidins can also play an important role in brain tissue of rats,which can effectively reduce early brain injury after subarachnoid hemorrhage from the inhibition of oxidative stress,inhibit inflammatory reaction and inhibit cell apoptosis.We can speculate that Oligomeric Proanthocyanidins may be a potential therapeutic agent for EBI after SAH.