Carnosine Attenuates Brain Oxidative Stress And Apoptosis After Intra Cerebral Hemorrhage In Rats

Intracerebral hemorrhage(ICH)is a fatal form of hemorrhagic stroke with high morbidity and mortality.The percentage of brain hemorrhage is approximately 20-30% in Chinese stroke patients.Among them,cerebral hemorrhage in the basal ganglia(including amygdala,lentiform nucleus,caudate nucleus and screen nucleus)accounts for about 70%.Cerebral hemorrhage,causes a series of physiological dysfunction,contains cytotoxicity,oxidative stress,excitotoxicity and inflammatory response.Previous studies have shown that the surrounding brain tissue of hematoma is ischemia and hypoxia because of the oppression of hematoma,moreover,red blood cell lysate hemoglobin,excitotoxicity and mitochondrial dysfunction will produce excessive ROS(reactive oxygen species)and a number of activated microglial cells,leading to the destruction of the blood-brain barrier,oxidative stress response,inflammatory response,apoptosis,cerebral edema,vasospasm and secondary brain injury.Among them,oxidative stress and inflammatory response play an important role in secondary brain injury after intracerebral hemorrhage.Therefore,given antioxidant stress and inhibition of inflammatory response maybe attenuate cerebral hemorrhage.Carnosine(β-alanyl-L histidine)is an endogenous dipeptide,which has a wide range of anti-oxidation,anti-cytotoxicity,anti-inflammatory response.Studies have shown that carnosine have shown anti-oxidation in the multiple brain damage,including in vivo and in vitro,but it’s still unclear in cerebral hemorrhag.In this study,we will explore the role of carnosine in rat ICH model,which is injected IV collagenase into caudate nucleus.Experiment purpose1.The ICH model was established by injecting IV collagenase into caudate nucleus of SD rats.We will study the improvement of neurological deficits in rats after intracerebral hemorrhage.2.To study the mechanism of carnosine to reduce the damage of brain tissue,the oxidative stress injury and inhibit the inflammatory reactionafter cerebral hemorrhage.3.To explore the neuroprotective effect and its mechanismof carnosine in ICH rats Research Methods1.we choose basal ganglia as the part of hemorrhage,the weight of SD rats is 310g-330 g,injection the IV collagenase into the caudate nucleus to produce ICH model,and then they were randomly divided into sham group(sham group),ICH+saline group(vehicle group),and ICH+carnosine group(carnosine group).2.The neurological scores evaluated at 72 h after ICH usingthe modiied neurological severityscore(mNSS)method;After anesthesia,the hemisphere of brain was removed immediately andweighed quickly to determine the wet weight.3.The brain hemisphereswere harvested at 72 h after ICH,including fresh and perfusion.The fresh brain the hemisphere was removed immediately to determine tight junction proteins ccludin(Western blotting detection),ZO-1,claudin-5,proinflammatory factorIL-1β,IL-6,TNF-α and the active caspase-3,cytochrome c.Another part of the fresh brain was used to detect ROS,MDA,3-NT and 8-OHDG and antioxidant enzymes SOD and GSH-Px.The perfused brain was used to determine the expression of ZO-1,vWF,active caspase-3 and mature microglia markers Iba-1 and activated microglia markers ED-1by immunofluorescence.Results1.The neurological score of the Carnosine groupsigniicantly reduced compared with the vehiclegroup.The water content in perihematomawas signiicantly decreased in Carnosinegroup as compared with the vehicle group.2.Immunofluorescence and Western blotting showed that the proteinexpression of ZO-1 signiicantly decreased in the vehicle group,whereas carnosine can attenuated this decrease.Carnosine can reduce the destruction of tight junction protein,reduce blood-brain barrier permeability and the brain edema.The levels of ROS,MDA,3-NT and 8-OHDG in the vehicle group were significantly higher than the sham group,while the activity of SOD and GSH-Px in the vehicle group was significantly higher than carbohydrate group(P <0.05).Carnosine can inhibit oxidative stress in the surrounding tissue of the hematoma after ICH.Compared with Vehicle group,carnosine can reduce the activation of microglia and inhibit the proinflammatory cytokines TNF-a,IL-1b and IL-6.The expression of Active Caspase-3 and TUNEL positive cells in the vehicle group was significantly increased,while the expression of the creatinine group was not obvious.Conclusion1.Injection of Ⅳ collagenase into caudate nucleus can successfully induce cerebral hemorrhage rats model.2.Intraperitonealadministration of Carnosine(1000mg/kg)signiicantly improved neurological function,ameliorated BBB disruption and decreased oxidative damage,reduced the microglial activation and neuronal apoptosisat 72 h in rat ICH model.Carnosine provides neuroprotective effect in experimental ICH.