Evaluation Of The Efficacy Of Agarwood Against Myocardial Ischemia

The report on cardiovascular diseases in 2013 China showed that 3.5 million persons died of cardiovascular diseases per year.Ischemic heart disease(IHD)is one of the leading causes of high morbidity and mortality worldwide over past decades.It is increasingly urgent to discover and develop comprehensive cadioprotection medicines.The vast territory and abundant resources in China have made it possible to seek for candidates from traditional medicines,which lay the foundation for the reasearch and development of TCM and ethnic herbal medicines.Among of them,Mongolian folk medicine,one of the four representative ethnomedicines,has a wide range of application in Inner Mongolia,China.Syringa pinnatifolia Hemsl.(SP),belonging to the family Oleaceae,is a deciduous shrub mainly distributed amongst the shrubs and spinneys of Helan Mountain,Inner Mongolia,China.The peeled stem,named 'Shan-chen-xiang' in Chinese,has been employed as a traditional medicine for hundreds of years in Inner Mongolia,China,for the treatment of cardiovascular symptoms,asthma,pain,and fever.Based on the traditionally clinic applicaion,this study focuses on the anti-myocardial ischemia by ethanol extract of SP using a model of ligation of left anterior descending(LAD)coronary artery in rats and mice,in additon to related mechanisms,characterization of pharmacological ingredients,and in vitro activity.This thesis is composed of the following sections:Review charpter describes the progress of the genus Syinga in the chemical and pharmacological effects over the past two decades.The results showed that the main chemical constituents are iridoids,lignans,phenylethanoids and their glycosides,organic acids,and essential oils.The pharmacological activities include anti-tumor,anti-hypertension,antioxidant,and anti-inflammatory effects provide the scientific evidence for the research of ethnomedicines,especially Mongolian folk medicine.SP,as one of the most representative Mogolian folk medicine,has a wide range of application in the treatment of cardiovascular diseases.Anti-myocardial ischemia effect of SP in rats:SD rats were used to establish the model of anti-myocardial ischemia by ligation of left anterior descending(LAD)coronary artery.After intragastric administration for 28 days consecutively,echocardiography method was used to evaluate the cardiac function and the pathological examination for the infarct edge areas of heart.The results showed that SP can obviously protect the ischemia heart function by increasing the levels of EF and FS,inhibit the inflammatory cells infiltration and fibrosis in the infarct edge areas of heart.This study preliminarily demonstrated the pharmacological effect against AMI and provided evidences toward the further research of SP.Anti-myocardial ischemia effect of SP in mice:C57BL/6 mice were used to value the anti-myocadial ischemia effect of SP.The mice were intragastric adiministrated for seven days consecutively,and then opertated by ligation of LAD coronary artery.The cardiac function changes were evaluated by echocardiography after 48 h,which showed that SP-pretreatment at 80 mg/kg had the effect of cardioprotection,and inhibiting inflammatory infiltration and collagen synthetic.The mechanisms are involved with inhibiting the expression of COX-1 and COX-2,thus keeping 6-keto-PGFla and TXB2 balanced in plasma and myocardium.SP pretreatment at 80 mg/kg can decrease the levels of CK-MB and LDH in serum,suggesting its protection on the cardiomyocytes.Besides,NF-?B and Jak-Stat signaling pathways were also inhibited obvisously in the SP-pretreatment group,suggesting inflammation involved in the anti-myocardial ischemic effect.Anti-myocardial ischemia evaluation on SP fractions:In order to discover the pharmacologically effective ingredients of SP against myocardial ischemia,the EtOH extract of SP(T)was fractioned into three fractions through two methods,including M was obtatined by HP-20 macroporous resin and X and Y were obtained by silica gel chromatography column.These four extracts(T,M,X,and Y)were assessed for the effects against AMI.After operation of LAD coronary artery,the suvived mice were intragastric adminiatrated for seven days consecutively.On the eighth day,the heart function were evaluated by echocardiography as above mentioned.The results showed that T,M,and X had significant cardioprotection effect compared with the model group by increasing EF and FS,especially decresing LVEDs level.At the same time,these three groups can decrease the levels of CK-MB and LDH,increase the activity of SOD.Besides,the inflammatory infiltration was also observed by pathological examination.This study clarified the effective ingredients,which helps to explicit the pharmacodynamic substance basis.However,the mechanism underlying it needs further exploration.Chemical characterization of SP:HPLC-MS-IT-TOF analysis indicated that peaks in tR 15-40 min are main components with moderate polarity,whereas those in tR 40-135 min are low poalr constituents,suggesting that the anti-myocardial ischemic effect of SP is probably attributed to the synergistic action of multiple components with various polarity,and it could also explain to some extent why SP is traditionally used in powder instead of in decoction.In vitro assays of single compounds:H9c2 cells inflammatary model is established by supernatant obtained by LPS-induced RAW264.7 cells,and employed for anti-inflammatory evaluation.The results showed that three compounds have moderate activity.Besides,H2O2-induced oxidative damage model was also used to evaluate these compounds,compound 50 showing significant protective activity.In addition,hypoxia-reoxygen(H/R)assessment results showed that five isolates can protect H9c2 cells from damage,but the related in vivo research and mechanisms need further study.In conclusion,the present study firstly demonstrated that SP has the cardioprotection and clarify the mechanisms related with regulating the expression of COX-1 and COX-2,thus keeping the ratio balance of PGI2 and TXA2 in blood and myocardium.The efficacy evaluations of different fractions and analysis of HPLC-MS-IT-TOF show that low and moderate poalr constituents are probably the effective ingredients,such as terpenoids and lignans.This study provides evidence for the application of ethnic herbal medicines,especially Mongolian folk medicine in the treatment of IHD.