Neuroprotective Effect And Mechanism Of STS On Ischemic Stroke Model Rats

BackgroundCerebrovascular disease(CVD)is a common and frequent disease of the nervous system.Stroke is the main type of CVD,with the characteristics of high morbidity,high mortality and high recurrence rate.Ischemic stroke is the most common type of stroke,accounting for 60% to 80% of all strokes.It is an important cause of population disability and death in the world,causing a heavy burden on society and families.Salvia miltiorrhiza,the traditional Chinese medicine in China,is the dry root and rhizome of plants of the Labiatae family,and has the effects of promoting blood circulation and removing blood stasis.The main active ingredient of Salvia miltiorrhiza is the sodium tanshinone ?A sulfonate(STS)produced after sulfonation of tanshinone ?A.It has high biological activity,strong water solubility and wide clinical use.Including regulating microvascular spasm and improving collateral circulation,reducing ischemia-reperfusion injury,protecting damaged nerve cells,etc.Therefore,it has broad application prospects in the treatment of cardiovascular and cerebrovascular diseases.ObjectiveThis experiment investigates the neuroprotective effect of STS on ischemic stroke model rats,explores its molecular mechanism or possible signaling pathways,and provides more experimental basis for treatment of ischemic stroke and enriches its intervention methods.Methods1.Experimental animals and groups 60 SD rats with a weight of 275 ? 30 g were divided into five groups randomly,with 12 in each group.Including sham operation group;Middle cerebral artery occlusion(MCAO);STS low,middle and high dose groups.2.Model preparation The model group and each dose group of STS were modified with the Longa method to establish a model of MCAO,which was reperfused after 2 hours of ischemia.Rats in the sham operation group were not placed with sutures,and only skin-cutting and blood vessel separation were performed.3.The method of Administration All five groups of experimental animals were given physiological saline or drugs according to kg body weight,as follows:The sham operation group and the model group were injected intraperitoneally with the same amount of normal saline 10ml/kg.STS low,medium and high dose groups were given STS stock solution 10mg/kg,20mg/kg,30mg/kg respectively after surgery.They were injected intraperitoneally during reperfusion 2 hours after ischemia and modeling.4.Mortality Count the number of deaths of rats in the 24 hours after operation.Calculation method: the number of dead rats in this group / the total number of rats in this group.5.Rat neurological function score The Longa score method was used for neurological function score at 12 and 24 hours after operation.0 points: normal nerve function;1 point: contralateral limb flexion when lifting the tail;2 points: circle to the affected side when walking;3 points: tilt or fall to the affected side when walking;4points: no spontaneous activity;5 points :death.6.Brain water content After the rats were sacrificed,the entire brain was removed,and the infarcted brain was weighed with an electronic precision balance.Then it was dried in an electric heating constant temperature drying oven to constant weight,weighed again and calculated the rat brain water content.7.Cerebral infarction volume The brain tissue was sectioned and stained with TTC.The digital camera was used to take pictures and the image analysis software was used to calculate the volume of cerebral infarction in rats.8.GSH,SOD,MDA and NO The infarcted brain tissue was homogenized and centrifuged to obtain the supernatant.The protein concentration was measured by the BCA method.9.SIRT1 and FOXO3? Western blot was used to detect SIRT1,FOXO3? protein expression levels.10.Statistical analysis Statistical analysis was performed using SPSS 19.0statistical software.Comparisons between groups were performed using independent sample t tests.The difference was statistically significant at P <0.05.Result1.Mortality All rats in the sham operation group survived,and the mortality in the model group was the highest.Compared with the model group,the mortality of the rats in middle and high dose group of STS significantly decreased,and the difference is statistically significant(P <0.05).2.Rat neurological function score The scores of rats in each group were significantly different.Compared with the model group,the neurological scores of each dose group of STS decreased gradually with increasing drug dose,and the difference was statistically significant(P <0.05).3.Brain water content It occurred in all groups of rats after operation.The water content in the model group was the highest,and the STS dose groups were alleviated to varying degrees.The high dose group had the most significant edema reduction.Compared with the model group,there were significant differences(P <0.01).4.Cerebral infarction volume The model group had the largest infarct volume,and the volume of each STS dose group decreased.Compared with the model group,the difference was statistically significant(P <0.05).The high-dose group had the smallest infarct volume.5.GSH,SOD,MDA,NO Model group has the least GSH and SOD,and the most MDA and NO.Compared with the model group,with the increase of the drug dose,the contents of GSH and SOD increased,and the levels of MDA and NO decreased with each dose of STS.There was a significant increase or decrease in the high-dose group,with significant differences(P <0.01).6.SIRT1 and FOXO3? Proteins in the SIRT1,FOXO3? model group were the lowest.Compared with the model group,the protein expression levels of the STS dose groups gradually increased with increasing drug doses,and the differences were statistically significant(P <0.05).ConclusionSTS can reduce the mortality of MCAO rats,neurological scores,cerebral edema,and cerebral infarction volume,and high-dose STS has the best effect.This protective effect may be achieved through the SIRT1/FOXO3? signaling pathway,which regulates the expression of downstream oxidative stress-related molecules.