Protective Effects Of Quercetin On Mitochondrial Function Adaptation Following Traumatic Brain Injury Via The Nrf2 Signaling Pathway

BackgroudTraumatic brain injury(TBI)is a high lethality and disability disease.After TBI,there was something wrong with metabolism of mitochondrial which would lead to short of energy supportion to normal neuron cells.Except that,large number of mitochondria morphology and structure would be destroyed,and led to the death of neuron cells.So,enhancing mitochondrial function adaptation after TBI can greatly reduce the damage of neuron cells.Part I Quercetin active the Nrf2 pathway and protect mitochondrial founctionObjective The present study was carried out to explore the protective effect of quercetin on mitochondrial function adaptation after TBI in the activation of the nuclear factor erythroid 2-related factor 2(Nrf2).Methods All of ICR mice were divided into four groups(n=20 for each group):sham group,TBI group,TBI + vehicle group,and TBI + quercetin group.The tissue was obtained 24h after TBI,exactly on the center of injury site,including contused and penumbra.Bax,cyt c of mitochondrial and Nrf2 of nuclear and cytosolic proteins were detected by western blotting.The transaction of Nrf2 was detected by immunohistochemical staining.Results The administration of quercetin following TBI significantly ameliorated the effects of the mitochondrial injury,such as the change of cyt c,MDA and so on.Quercetin markly promoted the translocation of Nrf2 from the cytoplasm to the nucleus,and increased the expression of Nrf2,and prevented the decline of antioxidant enzyme activities,including superoxide dismutase(SOD).Conclusion Quercetin administration may attenuate mitochondrial injury in experiment TBI,potentially via the mediation of the Nrf2 pathway.Part II The role of the Nrf2 pathway in quercetin's alleviating mitochondrial injury following traumatic brain injuryObjective The goal of study was to evaluate the role of the Nrf2 pathway in quercetin alleviating mitochondrial destruction in an experiment model of TBI.Methods Wild-type[Nrf2(+/+)]group and Nrf2 knock out[Nrf2(-/-)]group received TBI insult followed by quercetin administration at the corresponding time-points.Results Knock out of Nrf2 also declined the protection of mitochondrial Function after TBI.Conclusion Quercetin administration attenuate mitochondrial destruction via the mediation of the Nrf2 pathway.