| Objective:To prepare Ningxintong sustained-release pellets by reforming the dosage form of Ningxintong granules(composed of Radix Astragali,Rhizoma Chuanxiong,Radix Puerariae,Radix Isatidis and Asarum),and to intervene the vulnerable plaque model of atherosclerosis in rabbits with Ningxintong sustained-release pellets.The changes of TC,TG,LDL-C,HDL-C,hs-CRP,MMP-9,IL-6,IL-18 and ox-LDL before and after intervention were analyzed,and the feasibility of Ningxintong sustained-release pellets in stabilizing the vulnerable plaque was preliminarily explored.Methods:Fifty healthy New Zealand white rabbits weighing 2.5 ±0.5 kg were selected.After adaptive feeding for one week,six of them were randomly selected as the blank group named Group B and fed with normal rabbit diet.The other forty-four rabbits were fed with fat diet.At the end of the second week,calf serum protein was injected to make immune injury.Than abdominal aortic balloon injury was performed at the end of the fourth week,and at the end of the 12th week,Chinese spotted viper venom and histamine were given twice(48 hours and 24 hours before divided into groups)to trigger plaque rupture to establish a vulnerable plaque model of atherosclerosis in model rabbits.From the thirteenth week,according to their survival after modeling,animals in group A were randomly divided into six groups:groups A1,A2,A3,A4,A5 and A6 with six animals in each group.Administration in each group:Group A1:high dose of Ningxintong sustained-release pellets(9.0 g/kg/d);Group A2:conventional dose of Ningxintong sustained-release pellets(4.5 g/kg/d);Group A3:high dose of Ningxintong granules(9.0 g/kg/d);Group A4:conventional dose of Ningxintong granules(4.5 g/kg/d);Group A5:simvastatin tablets(0.9 mg/kg/d).Group A6 acting as model control group,without drug intervention,was given equal volume of distilled water by gavage.Blood samples were taken from the marginal ear vein of experimental rabbits in each group at the end of the 1st,12th,14th,and 16th week of the experiment to determine total cholesterol(TC),triglyceride(TG),high-density lipoprotein(HDL-C),and low-density lipoprotein(LDL-C)levels,and serum hypersensitivity C protein(hs-CRP),matrix metalloproteinase 9(MMP-9),interleukin 6(IL-6),interleukin 18(IL-18),and oxidized low-density lipoprotein(ox-LDL)expression levels were measured by enzyme-linked immunosorbent assay(ELISA).At the end of the 16th week,the abdominal aorta of experimental rabbits in each group was taken to observe the vascular smooth muscle and collagen proliferation using Masson staining.Results:1.The vulnerable plaque model of atherosclerosis was successfully established in New Zealand white rabbits by feeding,immune stimulation and aortic balloon injury,triggered by Chinese spotted viper venom(CRW)and histamine.2.At enrollment(end of the first week),there was no statistically significant difference in body weight or blood lipid levels among the groups of experimental rabbits,and they conformed to a normal distribution.At the end of the 16th week,the plasma TC,TG,and LDL-C levels of experimental rabbits in group A were higher than those in group B(P<0.05),meanwhile,the HDL-C level in group A was higher than that in group B(P<0.05).The TC and LDL-C levels in groups A1,A2,and A3 were lower than those in group A4(P<0.05),the HDL-C level in group A1 was higher than that in group A4(P<0.05),the TG level in group A1 was lower than that in group A2 and A2 was lower than that in group A4(P<0.05),and the TC,TG,and LDL-C levels in groups A1 and A2 were higher than those in group A5(P<0.05).3.Ningxintong sustained-release pellets had a significant inhibitory effect on the expression of serum inflammatory factors in experimental rabbits:At the end of the 16th week of the experiment,the expression levels of serum IL-6,IL-18,MMP-9,and hs-CRP in group A2 were lower than those in group A4(P<0.05).The levels of inflammatory factors IL-18,ox-LDL,and MMP-9 in group A1 were lower than those in group A2(P<0.05),and there was no significant difference in IL-6 and hs-CRP,between A1 and A2(P>0.05).4.Masson staining was used to observe the blood vessels,and it was found that the degree of interstitial cell fibrosis in the arterial tissue of experimental rabbits in each group:model group>Ningxintong Granule group>Ningxintong Sustained Release Pellets group>Simvastatin group>blank group.Conclusion:1.Ningxintong sustained-release pellets can regulate lipid metabolism,and the lipid-lowering effect of Ningxintong sustained-release dosage form is slightly better than that of granule type,especially reducing TC and LDL-C levels.2.Ningxintong sustained-release pellets can inhibit the expression of serum inflammatory factors.and the effect of Ningxintong sustained-release dosage form is slightly better than Ningxintong granules type.When inhibiting the expression of IL-18,ox-LDL and MMP-9,Ningxintong sustained-release pellets at high dose have better inhibitory effect in a dose-dependent manner.It may be associated with its inhibition of inflammatory response,intervention in oxidative stress,and inhibition of extracellular matrix degradation,ultimately making plaques tend to be stable.And through pathological observation,it was confirmed that Ningxintong sustained-release pellets inhibited the expression of inflammatory cells and reduced the inflammatory response better than Ningxintong granules.3.The preliminary experimental study on Ningxintong sustained-release pellets,a long-acting dosage form,showed that the sustained-release pellets had a better intervention effect on regulating lipid metabolism and inflammatory factor expression in animal models,and some detection indicators were superior to the traditional granule type,providing a useful objective envidence for future clinical application,pharmaceutical preparation,and mechanism research. |
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