| 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.6-O-methyl-scutellarein,which is one of the major metabolites of scutellarein in rats,might have better neuroprotective effects and stronger metabolic stability than scutellarin against brain ischemia.Whether 6-O-methyl-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 6-O-methyl-scutellarein against ischemic cerebrovascular disease,and to compare the treatment on ischemic cerebrovascular disease of 6-O-methyl-scutellarein with scutellarin and scutellarein through in vitro active assessments and in vivo animal experiments.Contents:1.Effective synthesis methods were explored to synthetise the compound of 6-O-methyl-scutellarein2.The in vitro antioxidant activities of 6-O-methyl-scutellarein compared with scutellarin and scutellarein were studied by measuring their scavenging capacities toward DPPH,ABTS+·,·OH and testing their reducing capacity on Fe3+.The results showed that 6-O-methyl-scutellarein had stronger scavenging capacities toward DPPH,ABTS+·,·OH and reducing capacity on Fe3+,but the capacities were worse than scutellarin and scutellarein.3.The in vitro anti-thrombotic activity of scutellarein compared with scutellarin and scutellarein were measured through TT,APTT,PT,FIB tests and platelet aggregation experiment.The results showed that 6-O-methyl-scutellarein could prolong TT and PT compared with the control;6-O-methyl-scutellarein had capacity of inhibiting platelet aggregation.And these effects of 6-O-methyl-scutellarein were better than scutellrin and scutellarein.4.Cerebral index,brain water content and the pathological changs with the administration of 6-O-methyl-scutellarein were measured to confirm its neuroprotective effect with scutellarin in the model of the middle cerebral artery occlusion(MCAO).The results showed that pretreatment with 6-O-methyl-scutellarein could significantly reduce cerebral index,brain water and neurological deficit score compared with the model group;the pathological changs of 6-O-methyl-scutellarein were better improved than that of scutellarin.5.Cerebral index,brain water content,Na+,K+,Ca2+,MDA,SOD,Ca2+-ATPase,Na+,K+-ATPase and the pathological changs with the administration of 6-O-methyl-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 present results showed that 6-O-methyl-scutellarein attenuated neuronal cell damage,reduced cerebral water content and improved the Ca2+-ATPase and Na+,K+-ATPase activity.Meanwhile,significant difference was found among various doses of scutellarin and 6-O-methyl-scutellarein.Our studies indicated that scutellarin and 6-O-methyl-scutellarein could improve neuronal injury,and 6-O-methyl-scutellarein had better protective effect than scutellarin in rat cerebral ischemia.6.The use of ultra fast liquid chromatography and Quadrupole Time-Of-Flight tandem mass spectrometry(UFLC-Q-TOF/MS)together with date collecting by MSE and data processing using mass defect filtering is described for the potent metabolites of 6-O-methyl-scutellarein in rat..The results showed that the reaction of 6-O-methyl-scutellarein in rat included methylation,acetylation,sulfate conjugation,glucuronide conjugation,et al.Conclusion:6-O-methyl-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. |
PDF Full Text Request