| BackgroundThe traditional Mongolian herb Baiyimucao is the over-ground part of Panzeria alaschanica Kupr.,still widely used in Mongolia region.It only grows in China and only it has medicinal record in this genus.Pharmacology active about Baiyimucao hasn’t been reported.Therefore,it has much practical significance to carry out the pharmacology studies on Baiyimucao,which will provide basis for the clinical use,discover new function and new treatment ideal etc.Abnormal vascular function or structure can cause a wide range of pathological changes,and it also is one of the main reasons that lead to cardiovascular diseases.Vascular proliferative diseases are a series of diseases that take the abnormal proliferation of intimal as outward manifestation.As the main components of the vascular wall,large numbers of clinical and experimental studies have shown that phenotype switching of VSMC is cytopathology basis in vascular proliferative diseases.Currently,there more and more researches on the switching of VSMC phenotype in the vascular proliferative diseases pathogenesis.ObjectiveThe Mongolian Medicine is an important part of national medicine theoretical system,developing the research of substance and mechanism on efficacious Mongolian herbal medicine is an important supplement of Mongolian medicine.Mongolian herb Baiyimucao full of ethnic characteristic,base on the preliminary research our study work on the Baiyimucao alkaloids,which is the main active component in Baiyimucao.Focus on the NADPH oxidase subtypes activation,the new drug target of neointimal,as the breakthrough point.To investigate the regulation mechanism of Baiyimucao alkaloids on the vascular smooth muscle cells in vascular proliferative diseases.Finally,we hope to clarify the pharmacological actions of Baiyimucao and explain the scientific meaning of Mongolian medicine theory.Method1.Baiyimucao crude herbs was extracted by heat reflux with 70%ethanol,then the extract was concentrated to a minimum volume,get 8g/mL of total alkaloid extract of Baiyimucao crude drug;KM mice were randomly divided into control group and treatment group,oral administration drug,the treatment group daily dose is 1332g·kg-1·d-1 and control group received an equal volume of vehicle alone;The animals were free access to standard chow diet and tap water;and observed continuously 14 days for mice hair,eating,drinking and other general activity or death situation.2.C57BL/6J mice were randomly divided into 2 major experimental groups,it being controls and surgery-treated animals.In the control group,it is shame-surgery group.And in the surgery-treated groups,mice were assigned to two subgroups,it being surgery group and drug administrated groups(simvastatin,aspirin,stachydrine,total alkaloids of Baiyimucao);In the surgery-treated groups acute neointimal proliferation was induced in the iliac artery of mice,by mechanically damaging the endothelium and combined intraperitoneal injection of LPS;21 days oral or injection treatment of different drugs after surgery,then animals were killed,CRP levels in the serum was detected,stripped femoral artery,formalin-fixed and routine paraffin sections,observe vascular tissue morphological changes by HE staining.3.Primary cultured rat aortic VSMC,identified it by SM α-actin fluorescence staining;VSMC proliferation was induced by PDGF-BB,then determine the experiment conditions through the dose-and time-effect experiments;Administration with the IC50 concentration of drugs on the PDGF-BB induced VSMC proliferation;Observation the changes of VSMC morphology and skeletal under fluorescence/inverted phase contrast microscopy;Western bolt was used to detect the NADPH isoforms NOX1,VSMC contractile function protein SM a-actin/SM-MHC and VSMC synthetic protein VCAM-1 expression level.Result1.Baiyimucao alkaloids have no toxic effect on the mice,and the test dose(1332g·kg-1·d-1)is 278 times of the maximum dose(4.79g·kg-1·d-1)used in our study.At the end of experiment,the weight of model group didn’t recovered,and the Aspirin group was heavier than before,others group were restored to the before.2.Vascular tissue morphology was observed that both stachydrine and total alkaloids of Baiyimucao have inhibition on the intimal proliferation caused by mechanical damage;the serum CRP test results shown there no significant difference among the groups.3.The dose and time effect experiments of PDGF-BB induced VSMC determined that under the 24 h of 40 ng/mL PDGF-BB-induced have the strongest effect;Stachydrine did not showed cytotoxicity on the VSMC with 6 mM～0.1 mM concentration,and has inhibition on the PDGF-BB-induced proliferation,the IC50 is 0.2 mM;Stachydrine can significantly inhibited PDGF-BB induced expression of NOX-1(P<0.01),inhibited the expression of synthesis phenotype protein VCAM-1(P<0.001),and inhibited reducing of contractile phenotype protein SM α-actin.Conclusion1.Animal experiments show that the Total Alkaloids of Baiyimucao and Stachydrine can inhibit the intimal proliferation which induced by mechanical injury combine LPS injection.As the Stachydrine is the major component of Total Alkaloids,suggested that Stachydrine is the main active substance of anti-intimal hyperplasia.2.Stachydrine can inhibit VSMC from contractile type converting into synthetic type;its possible mechanism may through inhibiting the expression of NOX-1 and VCAM-1,avoiding loss of the cytoskeleton proteins SM a-actin.Therefore,Stachydrine exerted effect of anti-intimal hyperplasia. |
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