The Effect Of Gallocatechin Gallate On Mitochondrial Function Of Brain Tissue In Rats After Resuscitation By Antioxidant Pathway

ObjectiveEpigallocatechin gallate(EGCG)is the main component of tea polyphenols that has strong anti-oxidative ability.The mechanism of cerebral ischemia-reperfusion injury after cardiopulmonary resuscitation is complex,including oxidative stress and energy metabolism disorders.It is reported that EGCG can reduce myocardial ischemia reperfusion injury and focal cerebral ischemia reperfusion injury through antioxidation,and it has not been reported on the effect of cerebral ischemia-reperfusion injury after cardiopulmonary resuscitation and the effect on mitochondria.This study established the whole brain ischemia reperfusion injury after cardiac arrest / cardiopulmonary resuscitation(CA/CPR).After the restoration of spontaneous circulation(ROSC),rats were given EGCG.The objective of our research was to investigate whether EGCG could reduce reactive oxygen species(ROS)generation,the effect on ERK signaling pathway?MPTP and energy metabolism to explore whether EGCG can improve the mitochondrial function of brain tissue after resuscitation by antioxidant pathway to reduce the whole cerebral ischemia reperfusion injury after CPR.MethodsThe rats were subjected to cardiac arrest(CA)7 minutes induced by electrical induction followed by cardiopulmonary resuscitation(CPR).The rats which spontaneous circulation was restored were randomly divided into three groups: low-does EGCG group(n=24),high-does EGCG group(n=24),normal saline(NS)group(n=24).The three groups were injected 2.4ml/kg EGCG solution(1.25mg/ml),EGCG solution(3.75mg/ml)and 0.9% normal saline injection in ROSC 1 minute.In addition,randomly choosing 24 SD rats into Sham group without CA/CPR.In ROSC 24 h,the rats in four groups were divided into three subgroups(n=8/each subgroup).and neurological function score,ROS fluorescence intensity,p-ERK relative express level and MPTP,ATP contents and ATP5C1 expression were compared in the four groups.Results 1.The neurological function scores: In ROSC 24 h,the neurological function scores in the Low-EGCG group(76.000±1.549)and the High-EGCG group(76.667±1.366)were higher than those in the NS group(75.400± 1.647)(Low-EGCG group VS.NS group,P=0.463;High-EGCG group VS.NS group,P=0.130;High-EGCG group VS.Low-EGCG group,P=0.466).2.The ROS fluorescence intensity: In ROSC 24 h,the ROS fluorescence intensity was significantly increased in the NS group(842.63±34.904)when compared to the Sham group(494.25±30.867)(P<0.01).The ROS fluorescence intensity in the High-EGCG group(661.00±28.631)was significantly lower than those in the NS group and the Low-EGCG group(753.75±14.28)(P<0.01).Compared to the NS group,the ROS fluorescence intensity in the Low-EGCG group was significantly decreased(P<0.01).3.The p-ERK relative expression level: In ROSC 24 h,the p-ERK relative expression level in the NS group(73.143±4.187%)was significantly increased when compared to the Sham group(49.263± 4.617%)(P<0.01).The p-ERK relative expression level in the High-EGCG group(55.986±4.611%)was significantly lower than those in the NS group and the Low-EGCG group(64.394±3.751%)(P<0.01).Compared to the NS group,the p-ERK relative expression level in the Low-EGCG group was significantly decreased(P<0.01).4.(1)MPTP: In ROSC 24 h,the mitochondrial fluorescence intensity in the NS group(2683.833±643.027)was significantly decreased when compared to the Sham group(5165.500±473.676)(P<0.01).The mitochondrial fluorescence intensity in the High-EGCG group(3492.500±761.265)was significantly higher than those in the NS group(P<0.05).Compared to the NS group,the mitochondrial fluorescence intensity in the Low-EGCG group(2917.333± 448.195)was increased(P=0.505).The lower the mitochondrial fluorescence density,the greater the openness of the mitochondrial MPTP.(2)The brain ATP contents: In ROSC 24 h,the brain ATP contents in the NS group(1.726±0.345 nmol/g)was significantly decreased when compared to the Sham group(4.291± 0.727nmol/g)(P<0.01).The brain ATP contents in the High-EGCG group(3.073±0.435 nmol/g)was significantly higher than those in the NS group and the Low-EGCG group(2.335±0.455 nmol/g)(P<0.01).Compared to the NS group,the brain ATP contents in the Low-EGCG was significantly increased(P=0.024).(3)The brain ATP5C1 express: In ROSC 24 h,the brain ATP5C1 express in the NS group(6.873±2.029 pg/mg)was significantly decreased when compared to the Sham group(16.224±2.375pg/mg)(P<0.01).The brain ATP5C1 express in the High-EGCG group(10.501±2.019 pg/mg)was significantly higher than those in the NS group and the Low-EGCG group(7.528±1.139 pg/mg)(P<0.01).Compared to the NS group,the brain ATP5C1 in the Low-EGCG was increased(P=0.506).ConclusionEGCG have protective effect on cerebral ischemia-reperfusion injury by reducing ROS level,the phosphorylation of ERK and reducing the MPTP opening,improving mitochondrial function.