The Mechanism Of Salvia Polyphenolic Acid On Improving Cerebral Ischemia/reperfusion Injury Through SIRT1/HMGB1 Signal Pathway In Rat

Objective To investigate the effects of salvia polyphenolic acid on improving cerebral ischemia/reperfusion injury through silencing information regulator protein 1(SIRT1)/high-mobility group box 1(HMGB1)signal pathway in rat.Methods292 male general-grade healthy SD rats were randomly divided into four groups:sham operation group(n = 73),model group(n = 73),salvianolic acid group(n = 73),inhibitor group(n = 73).In the sham-operated group,the right common neck,the internal and external carotid arteries were isolated,the blood vessels were not cut,and the line plug was not inserted.The other three groups were made the rat right middle cerebral artery ischemia model(middle cerebral artery ischemia model,MCAO).In addition,Danshen polyphenolic acid group was intraperitoneally injected with salvianolic acid at 100 mg / kg 1 hour before operation and 1 hour after operation.The inhibitor group was given a dose of 5 mg / kg at the same time point on the basis of Danshen group.The SIRT1 specific inhibitor EX 527 was injected intraperitoneally.The neurological deficits were assessed by modified neurological Severity Scores(m NSS)at 1,3,and 7 days after ischemia-reperfusion.The concentrations of SIRT1,HMGB1 m RNA in brain tissue were detected by RT-PCR at 1,3 and 7 days after ischemia-reperfusion.SIRT1,HMGB1,P-53 and NF-?B protein expression were detected by Western blot.Serum P-53,NF-?B levels were measured by ELISA.The histomorphology around the cerebral infarction was observed by HE staining first day after reperfusion.The terminal deoxynucleotidyl transferase-mediated nick end labeling(TUNEL)method was used to detect the neuronal apoptosis index.Result1 The neurological deficit scores measured by the m NSS method in the sham operation group were 0 points at 3 time points on the 1st,3rd,and 7th day.Compared with the model group and the inhibitor group,the m NSS score of the salvianolic acid group was significantly lower(F = 8.318? 9.483? 14.596,P< 0.05).2 The expressions of HMGB1,P-53 and NF-?B in salvianolic acid group were significantly lower than those in model group and inhibitor group at different time points.The expression of HMGB1,P-53 and NF-?B protein in inhibitor group was lower than that in model group.At the same time,it was significantly higher than the sham operation group(F=3282.245?1951.065?4869.379?2716.152?2038.176?1774.550?2554.386?4717.277?5797.773,P<0.05).The expression of SIRT1 protein in salvianolic acid group was significantly higher than that in model group and inhibitor group,while the expression level of SIRT1 protein in inhibitor group was significant.Higher than the sham operation group and the model group(F=3996.695?2614.746?4174.872,P<0.05).3 The expression of HMGB1 m RNA in salvianolic acid group was significantly lower than that in sham operation group,model group and inhibitor group at different time points.The expression of HMGB1 m RNA in the inhibitor group was significantly higher than that in the model group and lower than that in the sham operation group(F=135.565?199.523?135.2,P<0.05);The expression of SIRT1 m RNA in salvianolic acid group was significantly higher than that in model group and inhibitor group and sham operation group.The expression of SIRT1 m RNA in inhibitor group was significantly higher than that in sham operation and model group(F=568.489 ?485.729?212.083,P<0.05).4 The expressions of P-53 and NF-?B in peripheral blood of rats with salvianolic acid at different time points were significantly lower than those in the model group and inhibitor group.The expression of P-53 and NF-?B protein in the inhibitor group was significant.Lower than the model group was higher than the sham operation group(F=945.108?3530.741?2409.562?2122.983?2370.604?2329.962,P<0.05).5 In the sham operation group,the brain tissue structure of the hippocampus was clear and intact.The nerve cells were dense and arranged neatly.The cytoplasm of the neurons was rich and lightly stained,the nucleus was in the middle,and the nucleolus was clear.The glial cells are structurally intact,closely arranged,the nucleolus is clear,the cytoplasm is not red-stained,and the gap around the cells is dense and edema.In the model group,large nerve cells were missing,sparse,irregularly arranged,disordered,the number decreased,the interstitial edema was sparse,the cytoplasm of the nerve cells was red stained,and the nucleus shrunk,dissolved,and ruptured.It can be seen that the nuclear chromatin of the neuron is densely stained,forming a dense mass and showing apoptotic bodies;colloidal edema,sparse degeneration of glial cells,and increased glial cells around the infarct.The salvianolic acid group was significantly relieved compared with the model group,and the tissue structure was clear.The tissue structure integrity of the inhibitor group was not as good as that of the Danshen polyphenolic acid group,but it was better than the model group.6 The neuronal apoptosis index increased significantly,and there was significant difference between the model group and the sham operation group(P<0.05)first day after reperfusion in rat brain tissue.The neuronal apoptosis index of salvianolic acid group was significantly lower than that of model group and inhibitor group(P<0.05),while the neuronal apoptosis index of inhibitor group was significantly lower than that of model group(P<0.05).Conclusion Salvia polyphenols can alleviate cerebral ischemia/reperfusion injury by promoting SIRT1 transcription,inhibiting HMGB1 migration and expression,reducing the release of inflammatory factors P-53 and NF-?B in downstream pathways,and inhibiting neuronal apoptosis in rat.