Study On Structural Modification Of Salidroside And Neuroprotective Effect Of The Derivatives On Cerebral Ischemiareperfusion Injury In Rats

Obejective（1）To structural modify salidroside,screen for salidroside derivatives by in vitro cell model,measure the oil-water partition coefficient of the selected derivatives,and conduct acute toxicity tests;（2）To preliminary investigate the neuroprotective effects of salidroside derivatives on MCAO rats.Methods（1）The phenolic hydroxyl group and the alcoholic hydroxyl group in the salidroside molecule are structurally modified by esterification reaction.（2）The structurally modified salidroside derivatives were screened by the CoCl₂ induced PC12 cell hypoxia injury model,and the cell viability was determined by MTT assay.（3）The oil-water partition coefficient of the selected salidroside derivative was measured,and an acute toxicity test was performed to evaluate the fat solubility and toxicity.（4）Further pharmacodynamic examination was performed using the OGD-induced HUVEC cell model.（5）The effect of salidroside derivatives on the infarct volume of ischemic brain tissue in MCAO rats was investigated by TTC staining.（6）RT-qPCR was used to investigate the effects of salidroside derivatives on the expression of C1r,C3,Egr1,Egr4 and NeuN mRNA in ischemic brain tissue of MCAO rats.（7）The effect of salidroside derivatives on the expression of NeuN and Bcl-2 protein in ischemic brain tissue of MCAO rats was investigated by Western blotResult（1）In this study,26 salidroside derivatives with new chemical structures were synthesized for the first time,and confirmed the molecular structure by NMR and MS.（2）MTT screening results showed that the alpha-salidroside and its glycosyl modification products did not show pharmacological effects,while most of the modified products of phenolic hydroxyl groups had pharmacological effects.（3）The derivative p-benzoyl salidroside is low in toxicity and has fat solubility superior to salidroside.（4）The derivative p-benzoyl salidroside can inhibit the LDH level of OGD-induced HUVEC cell model,increase the expression level of Bcl-2 protein,and decrease the expression level of C3 protein.（5）MCAO rats were treated with p-benzoyl salidroside for 2 days.The cerebral infarct volume on the ischemic side of MCAO rats was significantly reduced.（6）MCAO rats were treated with p-benzoyl salidroside for 2 days.The expression level of the complement components C1r and C3 mRNA was significantly decreased,and the expression of Egr1,Egr4,and NeuN mRNA was significantly increased.（7）MCAO rats were treated with p-benzoyl salidroside for 2 days,and the expression of Bcl-2 and NeuN protein in ischemic brain tissue was significantly increased.Conclusion（1）The glycosyl group and the type of glycosidic bond in the salidroside molecule has a great influence on the drug effect,while the phenolic hydroxyl group has little effect on the drug effect,and the phenolic hydroxyl group can be acylated to improve the fat solubility and stability.（2）The derivative p-benzoyl salidroside can reduce the infarct volume of the cerebral ischemic side of MCAO rats,promote the expression of genes related to synaptic plasticity in MCAO rats,and inhibit the expression of genes related to complement system.It has neuroprotective effects.