Naringenin Exerts A Neuroprotective Effect Via The NOD2/RIP2/NF-?B Signaling Pathway In A Neonatal HIE Rat Model

Objective:To explore the protective effects and mechanism of naringin on hypoxic ischemic brain injury in neonatal rats.Methods:1.Seven-day old?P10?rat pups underwent right common carotid artery ligation followed by 2.5 h of hypoxia as previously described by Rice-Vannucci.40 seven-day neonatal Sprague-Dawley?SD?rat pups were randomly divided into sham operation group and hypoxic-ischemic brain damage group?HIBD group?.Time-course expression levels of endogenous NOD2 protein involved in naringin's protective effects were measured using western blot.2.96 seven-day neonatal SD rats were randomly divided into sham operation group,HIBD group,HIBD with low-dose naringenin group?50mg·kg-1,NG-L?and HIBD with high-dose naringenin group?100 mg·kg-1,NG-H?.Neurobehavior studies,HE staining and brain water content were measured at 48h after HIE.The expressions of NOD2?RIP2 and NF-?B were detected by western blot.The expresstion of TNF-?and IL-1?expression were measured using Enzyme linked immunosorbent assay.3.40 seven-day neonatal SD rats were randomly divided into sham operation group,HIBD group,MDP group,MDP with naringenin group?MDP+NG?and naringenin group?NG?.The expressions of NOD2,RIP2 and NF-?b was performed by western blot at 48h after HIE.Results:1 Time course results showed that the expression of NOD2 protein were significantly upregulated after HIE,peaking at 24 h post HIE and then decreased by 48h and 72 h.2Neurobehavioral studies showed that HIE induced a significant delay in development and resulted in cognitive and motor function deficits at 48h after HIE.The cognitive and motor function deficits had been had significantly reduced by naringenin?NG-L and NG-H?treatment?P<0.05?at 48 h post HIE.The pathological damage and the water content of brain tissues was markedly decreased by naringenin?NG-L and NG-H?treatment?P<0.05?.Western blot results revealed that the down-regulation of the expression of NOD2,RIP2 and NF-?B by naringenin?NG-L and NG-H?treatment?P<0.05?.The content of TNF-?and IL-1?in brain tissue were lower than HIBD group?P<0.05?.3 All downstream target proteins,NOD2,RIP2 and NF-?B showed to increase in HIBD group when compared to sham,and treatment group further increased their expression levels?P<0.05?at 48h after HIE.However,MDP effectively decreased expression of NOD2,RIP2and NF-?B at 48 h after treatment?P<0.05?.Conclusion:Naringin(50 mg·kg^-1,100 mg·kg^-1)decreased HIE-induced inflammation and improved neurobehavioral outcomes and the pathological damage which may be mediated by the NOD2/RIP2/NF-?B signaling pathway after HIE.