铁皮石斛超微粉对“过食膏粱厚味”致代谢性高血压病模型大鼠的影响

Effect of Dendrobii officinalis superfine powder on overeating greasy-induced metabolic hypertension in rats

铁皮石斛"滋阴清热"功效明确,民间有以粉末饮用的习惯,其超微粉具有溶出度高、饮用方便等优势,该实验观察了铁皮石斛超微粉对代谢性高血压病模型大鼠的作用及可能机制,为其在高血压病中的应用提供一定参考。采用高脂高糖高嘌呤饲料喂养模拟人类"过食膏粱厚味"建立代谢性高血压病大鼠模型,灌胃给予铁皮石斛超微粉400 mg·kg-1和200 mg·kg-1,连续20周。期间监测大鼠血压以及血脂、血糖及胰岛素等糖脂代谢相关指标,测定内毒素(LPS)及C反应蛋白(CRP)、白细胞介素6(IL-6)等炎性介质水平;检测一氧化氮(NO)和内皮素1(ET-1)水平并观察主动脉组织形态学和超微结构改变,同时对主动脉中LPS/Toll样受体4(TLR4)通路相关分子的表达进行测定。结果显示,铁皮石斛超微粉长期给药能明显降低代谢性高血压病模型大鼠收缩压(SBP)、舒张压(DBP)和平均动脉压(MBP),且能降低血中胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-c)、葡萄糖(Glu)、胰岛素(INS)水平及升高高密度脂蛋白胆固醇(HDL-c)含量;能降低血中LPS,CRP,IL-6及ET-1水平并提高NO含量;并能改善主动脉组织形态学及内皮超微结构异常;还能抑制主动脉中TLR4、髓样分化因子(MyD88)、IL-6、白细胞介素1β(IL-1β)、肿瘤坏死因子α(TNF-α)蛋白表达以及TNF-α和IL-1β mRNA表达。因此,铁皮石斛超微粉"滋阴清热"可能通过抑制血管中LPS/TLR4通路活化而改善血管功能和结构的异常,从而起到抗代谢性高血压病的作用。

Dendrobii officinalis, with a definite effect of nourishing Yin and clearing heat, has been a folk habit for drinking after being mixed with water. Because its superfine powder has the advantages of high dissolution and convenient drinking, we observed the effect of D. officinalis superfine powder on metabolic hypertension model rats and its possible mechanism in this experiment, which can be used as a reference for its clinical application for hypertension. The overeating greasy-induced metabolic hypertension model was established with high-fat, high-sugar and high-purine diet. These rats were orally administered with 400 mg·kg-1 and 200 mg·kg-1 of D. officinalis superfine powder for 20 consecutive weeks. During this period, blood pressure, blood lipid, blood glucose, insulin and other related indexes of glucose and lipid metabolism were monitored;the levels of lipopolysaccharide(LPS), C-reactive protein(CRP), interleukin 6(IL-6) and other inflammatory mediators were measured;the levels of nitric oxide(NO) and endothelin-1(ET-1) were detected, and the histomorphological and ultrastructural changes of aorta were observed. In addition, the expression of LPS/TLR4 pathway-related molecules in aorta was determined. The results showed that long-term administration of D. officinalis superfine powder significantly reduced the levels of systolic blood pressure(SBP), diastolic blood pressure(DBP) and mean arterial pressure(MBP) in metabolic hypertension model rats, decreased the levels of total cholesterol(TC), triglyceride(TG), low density lipoprotein cholesterol(LDL-c), glucose(Glu), and insulin(INS) levels in blood, increased the contents of high density lipoprotein cholesterol(HDL-c),decreased the LPS, CRP, IL-6 and ET-1 levels in blood and increased NO content. Furthermore, it improved the abnormality of aortic histomorphology and endothelial ultrastructure, and inhibited the protein expression of TLR4, myeloid differentiation factor(MyD88), IL-6, interleukin-1 β(IL-1β), and tumor necrosis factor-α(TNF-α) as well as mRNA expression of TNF-α and IL-1β in aorta. In conclusion, D. officinalis superfine powder may improve the abnormal function and structure of blood vessels by inhibiting the activation of LPS/TLR4 pathway, thus playing a role against metabolic hypertension.