Effects Of Tetrahydroxystilbene Glucoside On Expression Of NGF,VEGF And CD34 In Elderly Rats Suffered Ischemia-reperfusion Injury

Background and objectiveThe focal zone consists of ischemia central zone and ischemia penumbra after ischemia brain damage.Between the two are dynamic process of pathophysiologic,the ischemia penumbra will gradually reduce with the time going on.So tinely restoring blood supply will contribute to restore neural function.Studies have shown that nerve growth factor (NGF)not only play a neurotrophic role in the central nervous system, but also be able to increase the expression of vascular endothelial growth factor (VEGF),then promoting the formation of new blood vessels and improve blood supply,Finally,playing a protection role to nerve cells, CD34 as the new blood essels markers can be used to detect the new blood essels.Presently, Presently,it was reported that Chinese medicine polygonum multiflorum thunb and its active pharmaceutical ingredients tetrahydroxystilbene glucoside (TSG) had protective effects on cerebral ischemia,but the mechanism was not fully understood,in addition Studies have shown the expression of endogenous NGF increased when treated with TSG in AD rats and improving the ability of study and memory.In this study, we observed the protein expression of NGF,VEGF and the effect of TSG.Using CD34 detect the new blood essels.The impairment of brain tissue and apoptotic cells were detected to investigate the mechanism of neuroprotective.The results may provide the experimental bases for the new drug development and therapeutic strategy on cerebral ischemia.MethodsThe healthy male sprague-dawley rats weighting 400～500g were randomly divided into three groups:control group (n=24),model group (n=24),TSG group (60mg/kg/d, n=24).After 7 days intragastric(ig) administration of TSG (treatment groups) or natural saline (model group). Transient focal cerebral ischemia was induced by middle cerebral artery occlusion (MCAO). Then, neurological behavior evaluation was performed by the method of Longa's scoring.The pathologic changes were observed by hematoxylin and eosin (HE)staining at 6h,12h,24h and 7d.The protein expression of NGF,VEGF and CD34 were measured with methods of immunohistochemistry.Results1.Compared with I/R group,treatment with TSG could decrease the grade of the rat neurological defects except at 6 h after reperfusion.2.Typical neural necrosis could be observed in I/R group and both TSG groups by HE staining at 24 h after reperfusion.3.The protein expression of NGF,VEGF were detected few in control group.The protein expression of NGF and VEGF increased at 6h after cerebral reperfusion, reached maximum at 24h, reduced at 48h and maintained few at 7d in NS control group and TSG groups.The protein expression of CD34 was not detected in control groups,and was detected at 6h after cerebral reperfusion,increased at 24h,48h and 7d. reached maximum at 7d in model groups and TSG groups.Compared with control group, model group could significantly increase the protein expression of NGF,VEGF and CD34 after reperfusion.Compared with model group treated with TSG could significantly increase the protein expression of NGF,VEGF and CD34 after reperfusion.ConclusionsTetrahydroxystilbene glucoside probably through inducing the increase of NGF in elderly rats suffered ischemia-reperfusion injury to raise the expression of VEGF,and then promoting the formation of new blood vessels,Finaly, playing a protection role to nerve cells.