Study on the protective effect of Hypericum perforatum on cerebral ischemia-reperfusion injury in rats and its mechanism / 中国药房

ABSTRACT

OBJECTIVE To study the protective effect and potential mechanism of Hypericum perforatum on cerebral ischemia- reperfusion in rats. METHODS The male SD rats were randomly divided into sham operation group， model group， positive control group （nimodipine 0.012 g/kg）， H. perforatum high-dose and low-dose groups （5.212， 1.303 g/kg）， with 10 rats in each group. Except for sham operation group， the left middle cerebral artery ischemia-reperfusion model was established with the modified suture method. Administration groups were given relevant medicine intragastrically since the second day after surgery， once a day， for 7 consecutive days. The neurological function scores of rats were measured before drug intervention （the first day after modeling） and after the last administration， and the cerebral infarction after the last administration was observed using TTC staining method；HE staining and TUNEL staining methods were used to observe the pathological changes of the cerebral cortex and hippocampus， and the apoptosis of nerve cells， respectively. Western blot and RT-PCR were used to observe the protein and mRNA expressions of erythropoietin （EPO）， erythropoietin receptor （EPOR）， Janus kinase 2 （JAK2） and signal transduction and activator of transcription 3 （STAT3）， and protein expression of phosphorylated STAT3 （p-STAT3）， respectively. RESULTS Compared with sham operation group， neurological function score and the proportion of cerebral infarction in model group were significantly increased before intervention and after the last administration （P＜0.01）， with significant damage to nerve cells in cerebral cortex and hippocampus， an increase in apoptotic nerve cells， and a significant increase in apoptosis rate （P＜0.01）； protein and mRNA expressions of EPO and EPOR in the brain tissue were significantly reduced （P＜0.01）， while the protein expressions of JAK2， p- STAT3 and STAT3， and mRNA expressions of JAK2 and STAT3 were significantly increased （P＜0.01）. Compared with model group， the damage and apoptosis of nerve cells in cerebral cortex and hippocampus of rats in administration groups were improved， and the quantitative indicators were almost significantly improved （P＜0.05 or P＜0.01）. CONCLUSIONS H. perforatum has a protective effect against cerebral ischemia-reperfusion injury in rats， and the related mechanism may be related to the regulation of EPO-mediated JAK2/STAT3 signaling pathway.