[Establishment of vulnerable plaque model by mast cell activation in adventitia and evaluation of effectiveness of intervention of Shenlian tablet].

This study was designed to investigate the activity of Shenlian tablet in stabilization of the atherosclerosis (As) plaque in apoE(-/-) mice and explore the mechanisms. Rat peritoneal mast cells were randomly allocated and treated with Shenlian tablet (100, 50, 25, 12.5 mg·L(-1)) or cromoglicate sodium (200 µg·L(-1)) for 2 h before exposure to substance P. Histamine, tryptase, IL-1ß and NF-κB were measured in the cell culture supernatant by ELISA assay. The plaque formation was induced by common carotid artery cannula method combined with high-fat diet in apoE(-/-) mice, and the plaque instability was induced by substance P through local mast cell degranulation. Mice were divided into eight groups that included the model 1 (M1, sham-operated group), M2 (carotid artery cannula combined with high-fat diet）, M3 (M2 combined with substance P 0.5 µg/mouse, Shenlian extract (95, 190 and 380 mg·kg(-1)·d(-1)), atorvastatin (2.6 mg·kg-1·d(-1)) and normal control group. Total cholesterol (TC), high-density lipoprotein (HDL-C), high-sensitivity C-reactive protein (hs CRP), matrix metalloproteinases 9 (MMP-9) and histamine were measured by ELISA. Thickness, plaque area, mast cell degranulation were observed by hematoxylin and eosin staining, toluidine blue staining. CD117 antigen expression were observed by confocal microscopy. Intracellular phosphorylation was detected using the Bio-Plex 6-plex phosphoprotein assay kit. The results show that the mast cell membrane was stabilized by Shenlian tablet. Histamine, tryptase, interleukin l-ß and NF-κB exhibited a significantly reduction in the Shenlian tablet-treated group (P < 0.05 or P < 0.01). Substance P significantly enhanced activation and degranulation of adventitial mast cells. In addition, it increased adventitia inflammatory cells infiltration and promoted intraplaque hemorrhages in apoE(-/-) mice model group. The proliferation, degranulation and inflammation of mast cell were significantly inhibited by Shenlian tablet. On the other hand, the same treatment decreased hs-CRP, MMP-9 and histamine in serum. IκB, p38 MAPK phosphorylation, intraplaque hemorrhage and collagen degradation were reduced in the presence of Shenlian tablet, which increased the stability of the As plaque. The results show that the vulnerable plaque model induced by mast cell activation in adventitia was established. Shenlian tablet exhibited a protective effect in this model. Shenlian tablet may increase the plaque stability via inhibition of mast cell-mediated inflammatory response.

[Effect of Shenlian extracts on blood flow and vessel pathological changes in rabbits carotid atherosclerosis model induced by low shear stress].

Lipid accumulation in the vessel wall and tunica intima vasorum pathological changes are important factors in the development of atherosclerosis, which are closely related with hemodynamics. In this paper, we established a model of local low shear stress in rabbits using carotid artery cannula and a high cholesterol diet for 2 weeks, 4 weeks and 8 weeks. The effects of Shenlian extract on blood flow, vascular pathology formation and lipid metabolism were assessed by electromagnetic blood flow meter and hematoxylin-eosin staining of the proximal end in carotid artery at different times. The results demonstrate that the relationship between blood flow and shear stress for control, atorvastatin, Shenlian extract high-dose, Shenlian extract middle-dose, and Shenlian extract low-dose were linearly related. The blood flow and the shear stress of proximal end in carotid artery of Shenlian extract (1.12, 2.24, 4.48 g x kg(-1)), and atorvastatin (4.7 x 10(-4) g x kg(-1)) were significantly (P < 0.05)increased compared with the control. Plasma total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) ,and high density lipoprotein cholesterol (HDL-C) were markedly decreased with the increasing of dose and time. This study is the first to prove that the inhibition of Shenlian extract on low shear stress (LSS) induces rabbits carotid atherosclerosis with increasing blood flow and decreasing lipids and vessel pathological changes.

Effects of shenlian extracts on atherosclerosis by inhibition of the inflammatory response.

OBJECTIVE: Inflammation plays a critical role in atherosclerosis, and this inflammatory reaction is being intensively studied. Shenlian Extracts, an active ingredient of Chinese medicinal herbs, is believed to have multiple therapeutic and preventive effects against human vascular diseases, including atherosclerosis. Our work investigated whether Shenlian Extracts serves as an anti-inflammatory agent during atherogenesis. METHODS: We established a model of atherosclerosis in rabbits using balloon angioplasty and a high cholesterol diet. The effects of Shenlian Extracts on vessel structure and inflammation were assessed by hematoxylin-eosin staining of the femoral artery, measurement of inflammation-related factors in serum or vascular tissue, and radioimmunoassay. Enzyme linked immunosorbent assays (ELISA), flow cytometry and western blots were also performed. RESULTS: We show that oral pre-treatment with Shenlian Extracts suppressed the pathological changes associated with atherosclerosis and that graded doses of Shenlian Extracts reduced total serum levels of cholesterol (90, 180 and 360 mg/kg), triglyceride (180 and 360 mg/kg), and LDL-c (90, 180 mg/kg). Various doses of Shenlian Extracts reduced serum content of TNF-alpha (180 and 360 mg/kg), CRP (90, 180 and 360 mg/kg) and IL-8 (360 mg/kg) (P < 0.05), but led to no significant changes in IL-1beta levels. Treatment with Shenlian Extracts also significantly reduced VCAM-1 levels (90 and 360 mg/kg) and IGF-1 levels (90 and 180 mg/kg) in vascular tissue but had no significant effect on ICAM-1 and MCP-1 levels. Finally, Shenlian Extracts significantly reduced the abnormal expression of CD18 in monocytes in a dose-dependent manner. CONCLUSION: These results suggest that Shenlian Extracts may play a direct role in preventing and treating atherogenesis by inhibiting the inflammatory reaction, providing insights into the possible mechanism underlying the anti-atherosclerotic actions of Shenlian Extracts.