霍山石斛对高脂诱导的LDLR基因敲除小鼠动脉粥样硬化和血管钙化的影响

Dendrobium Huoshanense C.Z.Tang et S.J.Cheng inhibits the development of atherosclerosis and vascular calcification induced by high-fat diet in LDLR-/-mice

目的研究霍山石斛(DH)对高脂食物诱导的雄性低密度脂蛋白受体基因敲除(LDLR-/-)小鼠动脉粥样硬化(As)和血管钙化的影响,并初步探讨其作用机制。方法LDLR-/-小鼠随机分为对照组和霍山石斛组(DH组)。喂养18周后对小鼠处以安乐死,收集血清、主动脉、肝脏等。分析血清中谷丙转氨酶(ALT)、谷草转氨酶(AST)、碱性磷酸酶(ALP)、总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDLC)和低密度脂蛋白胆固醇(LDLC)的水平;对全主动脉及其根部切片进行油红O染色,检测动脉粥样硬化斑块面积;主动脉根部切片分别做天狼猩红和茜素红S染色,分析斑块稳定性和血管钙化程度;再对肝脏及其冰冻切片进行检测,分析其脂质积累情况。结果霍山石斛喂食LDLR-/-小鼠18周后,与对照组比较,DH组小鼠血清TG水平下降(P<0.05),但不影响血清中转氨酶及其他脂质水平。与对照组比较,DH组小鼠全主动脉及主动脉根部的粥样硬化斑块面积均减少约20%(P<0.05);斑块损伤区域的胶原纤维含量增加约70%(P<0.05),从而提高斑块的稳定性,且斑块中坏死核心的发生发展也受到明显抑制;对主动脉根部切片的茜素红S染色发现,对照组主动脉根部钙化面积占比1.34%,而DH组主动脉根部钙化面积占比为0.88%,减少了约34%(P<0.01)。结论霍山石斛可以抑制动脉粥样硬化和血管钙化的发生发展。

Aim To study the effect of Dendrobium Huoshanense C.Z.Tang et S.J.Cheng(DH)on the development of atherosclerosis and vascular calcification induced by high-fat diet in LDLR-/-mice and the possible mechanisms.Methods Male LDLR-/-mice were randomly divided into 2 groups and received the following treatment:High-fat diet(control group);HFD containing DH(DH group).The treatment was lasted for 18 weeks.At the end of treatment,all the mice were anesthetized followed by collection of blood,aorta and liver samples.The serum was prepared followed by determination of alanine aminotransferase(ALT),aspartate aminotransferase(AST),alkaline phosphatase(ALP),total cholesterol(TC),triglyceride(TG),high density lipoprotein cholesterol(HDLC)and low density lipoprotein cholesterol(LDLC)levels.Whole aorta and frozen cross sections of aortic root were prepared,and the lesions in en face aorta and aortic root cross sections were determined by oil red O staining.Frozen cross sections of aortic root were also stained by Sirius Red and Alizarin Red S to determine the plaque stability and vascular calcification.Liver frozen sections were prepared and used to determine hepatic lipid content by oil red O staining.Results After 18 weeks,DH lowered serum TG to(2.31±0.16)mmol/L compared to the control group(3.76±0.47)mmol/L(P<0.05),but had no effect on transaminase level and otherlipid profilesin serum.Meanwhile,DH significantly reduced lesions in en face aorta and sinus lesion of aortic root by 20%(P<0.05).It also increased collagen content by 70%in plaques(P<0.05),promoted lesion stability and reduced necrotic cores in arterial wall.At last,Alizarin Red S staining showed that the development of vascular calcified area,which was 0.88%in DH group while 1.34%in control group,was attenuated by 34%(P<0.01).Conclusion DH inhibits the development of atherosclerosis and vascular calcification.