Résumé
Objective The preventive effect of epigallocatechin gallate(EGCG)on hyperglycemia-induced hemorrhagic transformation(HT)was analyzed,and the underlying mechanisms were further explored.Methods Male SD rats were randomly divided into sham operation group(Sham,n = 20),model group(n = 27),hyperglycemia model group(HG,n = 43),and EGCG group(n = 43).In the model group,only the electrocoagulation cerebral ischemia model was established,and the HG group and the EGCG group were used to establish the HT model with acute hyperglycemia combined with electrocoagulation cerebral ischemia model.In addition,EGCG was adminis-tered by gavage for 5 days before cerebral ischemia at a dose of 50 mg/kg/d.Further studies confirmed the relevant targets by using network pharmacology to predict the potential targets and pathways of EGCG in the occurrence of HT.Results Compared with the model group,the mortality rate of the rats in the HG group was significantly increased[21.2%(6/27)vs.51.2%(22/43),P＜0.05].The mortality of rats in the EGCG group was significantly lower than that in the HG group[30.20%(13/43)vs.51.2%(22/43),P＜0.05].Second,mNSS,Longa score and infarct volume in the EGCG group were significantly lower than those in the HG group(P＜0.05).The incidence of HT in the HG group was higher than that in the model group(59.3%vs.90.7%).EGCG significantly reduced the incidence of hyperglycemia-induced HT to 69.8%.Compared with the HG group,EGCG decreased the hemoglobin content from(53.42±5.11)mg/dL to(37.04±2.39)mg/dL respectively(P＜0.05).Network pharmacology revealed that Nrf2-Keap1-mediated neuroinflammation may be associated with hyperglycemia-induced HT.The expression of Nrf2 and Keap1 was significantly decreased and the expression of TLR4 and phosphorylation of NF-κB was significantly increased in the HG group,but EGCG reversed this process.Conclusion EGCG pretreatment prevents the occurrence of HT,which may be related to the neuroprotection mediated by activation of the Nrf2-Keap1 signaling pathway.