The Study Of Scutellrein On The Protective Effect Against Brain Ischemia

Cerebrovascular disease is a common and frequently-occurring disease that seriously endangers human health.It is one of the leading causes of death and disability worldwide,especially ischemic cerebrovascular disease,which is the most frequently prevalent.There are many active substances which has protective effect against hypoxic ischemic brain damage in TCM and natural drugs.Therefore looking for the active substances with anti-cerebral ischemia activity from TCM and natural drugs is one of the important methods to discover and develop new drugs.Scutellarin(4,5,6-trihydroxyflavone-7-glucuronide),the major bio-active compound in breviscapine extracted from chinese herb of Erigeron breviscapus(vant.)Hand.-Mazz.has been clinically used to treat acute cerebral infarction and paralysis induced by cerebrovascular diseases such as hypertension,cerebral thrombosis,cerebral haemorrhage in China since 1984.Although breviscapine has been clinically used for a long time,it has such disadvantages as poor solubility,poor absorption and low bioavailability.Interestingly,some researchers found that scutellarin was mainly absorbed in the form of its hydrolyzed product scutellarein by intestinal,and scutellarein has better solubility,better absorption and higher bioavailability than scutellarin.Pharmacodynamics confirmed that scutellarein had better protective effect than scutellarin in rat cerebral ischemia,which may be a promising potent agent for the therapy of ischemic cerebrovascular disease.Whether scutellarein has better protective effect against ischemic brain injury than scutellarin or not?It need to be further studied.Objective:The aims of this study were to prove the effectiveness of scutellarein against ischemic cerebrovascular disease,and to compare the treatment on ischemic cerebrovascular disease of scutellarein with scutellarin through in vitro active assessments and in vivo animal experiments.Contents:1.The in vitro antioxidant activities of scutellarein compared with scutellarin were studied by measuring their scavenging capacities toward DPPH,ABTS+�,�OH and testing their reducing capacity on Fe3+.The results showed that scutellarein had stronger scavenging capacities toward DPPH,ABTS+�,�OH and reducing capacity on Fe3+ than scutellarin.And the effects were dose-dependent.2.The protective effect of scutellarein compared with scutellarin on H2O2-induced cytotoxicity in PC 12 cells were studied by using MTT assay method.The results showed that when PC 12 cells were coincubated with scutellarein and H2O2,H2O2-induced cell toxicity was significantly attenuated;the protective effect of scutellarein was dose-dependent.And scutellarein showed a significantly better protective effect than scutellarin.3.The in vitro anti-thrombotic activity of scutellarein compared with scutellarin were measured through TT,APTT,PT,FIB tests and platelet aggregation experiment.The results showed that scutellarein could prolong TT and APTT compared with the control;scutellarein had capacity of inhibiting platelet aggregation.And these effects of scutellarein were better than scutellrin.4.Cerebral index,brain water content,SOD activity,MDA content and the pathological changs with the administration of scutellarein were measured to confirm its neuroprotective effect with scutellarin in the model of incomplete cerebral ischemia/reperfusion induced by occlusion of bilateral common carotid artery.The results showed that pretreatment with scutellarein could significantly reduce cerebral index,brain water content,MDA content and enhance SOD activity compared with the model group;the pathological changs of scutellarein were better improved than that of scutellarin.5.Neurological scores,brain infarct volume and brain water content with the administration of scutellarein were measured to compare its neuroprotective effect with scutellarin in the MCAO rat model established by occlusion of middle cerebral artery.The results showed that compared with the model group,pretreatment with scutellarein could significantly decrease neurological scores,brain infarct volume and brain water content in the MCAO rat models.And these effects of scutellarein were better than scutellrin.6.The use of ultra high performance liquid chromatography and Quadrupole Time-Of-Flight tandem mass spectrometry(UPLC-Q-TOF/MS)together with date collecting by MSE and data processing using mass defect filtering is described for the potent metabolites of scutellarein in rat.The results showed that the reaction of scutellarein in rat included reduction,hydroxylation,methylation,acetylation,glycine conjugation,glucuronide conjugation,et al.Conclusion:Scutellarein had better protective effect than scutellarin in rat cerebral ischemia,which would be a promising potent agent for the therapy of ischemic cerebrovascular disease.