Study Of Protection Of Aqueous Extract Of Arctium Lappa Root On Blood Vessel Endothelium Dysfunction Of Hypertensive Rats

Aim To study the effects and mechanism of aqueous extract of arctium lappa root on blood vessel endothelium of hypertensive rats by using hypertensive rats model as research object, rat tail artery systolic hypertension,thoracic aortic porphology,expression levels of inflammatory cytokines IL-6,vascular endothelial ICAM-1,CRP and TNF-α were obser-ved.Method The hypertensive rats model were induced by N-nitro-Larginine,and randomly divided into normal control group, model control group, positive control group(15mg/kg Captopril), aqueous extract of arctium lappa root low(0.5g/kg), medium(1.0g/kg), high(2.0g/kg) dose group.After six weeks of continuous gavage administration, rat tail artery systolic pressure were measured in the environment of constant temperature,quiet and awake.After fasted for 12 h,rats were given 10% chloral hydrate 0.3ml/100 g intraperitoneal injection of anesthesia, and taken abdominal aortic blood 4 mL. ELISA method was used to measure the expression levels of inflammatory cytokines IL-6,CRP,TNF-α,HE staining was used to observe the morphological changes of thoracic aorta after 200 ×high magnification and immunohistochemical method was used to measure ICAM-1’s expression levels.Results(1) The difference was statistically significant in systolic blood pressure between groups(F=4683.644,P<0.001).Before administration, the systolic blood pressure of each treated group and model group were higher than normal control group(P<0.05).Systolic blood pressure decreased after treatment, the systolic blood pressure of treated groups were lower than the model group(P<0.05), and it was basically stable until 36 d. There was no significant difference between high-dose group of burdock root aqueous extract, positive control group and normal control group in systolic blood pressure betweeen 36~42d(P>0.05).(2) Positive control group and high-dose group of burdock root aqueous extract can significantly improve the thoracic aorta endothelial damage, there wasn’t endothelial cell loss, blood cell adhesion,and elastic fibers arranged in order. Medium-dose group has occasional loss of endothelial cells, blood cell adhesion and elastic fibers derangement.The loss of endothelial cells, blood cell adhesion and intimal thickening were still visible in low-dose group, but elastic fibers were arranged neatly compared with the model group.(3) The level of serum inflammatory cytokines IL-6,vascular endothelial CRP, TNF-α and ICAM-1were significantly reduced of each treatment group, and significantly different with the model group(P< 0.05).Conclusion Aqueous extract of arctium lappa root can significantly improve hypertension rat’s blood vessel endothelium edysfunction, the mechanism may be related to the inhibition of inflammatory cytokines like IL-6,CRP,TNF-α and expression of ICAM-1,so it can improves the vascluar endothelial chronic hypertension inflammatory response.