【作者】 杨利；

【导师】 黄昆仑； 罗云波；

【作者基本信息】 中国农业大学 ， 营养与食品安全， 2015， 博士

【摘要】 以罗布麻茶为材料,以SHR为高血压模型动物,研究罗布麻血压调节作用及其生理机制。结果表明,罗布麻对SHR具有血压调节的作用,血压调节的时-效曲线呈现先升高后降低的“双向调节”特点。但罗布麻降压时相及降压作用起效慢,前两周并不明显,到第三周以后呈现明显的先升高后下降的时-效规律,降压作用发生在灌胃后5h之后,在8h左右降压幅度达到最大。6周的慢性降压实验表明,罗布麻可缓慢降压,在第三周后降压作用明显,降压幅度稳定,大约在15mmHg左右。同时,连续6周罗布麻处理,对SHR的心率、血脂等无显著影响；对SHR具有明显的利尿作用,并且促进尿中Na+、K+、Cl-离子的分泌。因此,罗布麻的血压调节降压时相的出现以及慢性降压作用的生理机制可能通过其利尿作用实现。以罗布麻叶为材料,以Wistar大鼠为实验动物,研究罗布麻水提物的急性利尿作用。结果表明,罗布麻水提物可促进大鼠尿液的分泌,在给药后6h、8h尿量显著增加。同时,罗布麻可促进大鼠6h尿中K+、Na+、Cl-的分泌,且均随剂量的增加而增加。这与罗布麻血压调节中稳定的降压时相出现的时点相吻合,进一步说明罗布麻的降压时相的出现可能是通过其利尿作用实现的。用传统的有机溶剂对罗布麻叶水提物有效部位进行了萃取分离,得到了醇提部位(EF)、醇沉部位(ER),正己烷部位(nHF)、乙酸乙酯部位(EAF)、正丁醇部位(nBF)和水相部位(WF)。以各分离部位为材料,以Wistar大鼠为实验动物,进行急性利尿实验,结果表明,醇提部位在促进Wistar大鼠尿液的分泌以及尿液电解质K+、Na+、Cr-的分泌中起主要作用。其中,醇提部位中萃取分离得到的正丁醇部位不仅在促进尿液分泌中起主要作用,同时也在促进尿Na+的分泌中起主要作用,而促进尿K+和Cl-分泌的作用主要是通过醇提部位中分离得到的水相部位实现的。经相关性分析,罗布麻叶中总酚和总黄酮均与利尿指数呈现显著的正相关(r=0.886,p<0.01；r=0.882,p<0.01)。其中,异槲皮苷(r=0.747,p<0.01),金丝桃苷(r=0.758,p<0.01),芦丁(r=0.793,p<0.01)以及绿原酸(r=0.650,p<0.05)均与利尿指数呈显著正相关关系,因此,罗布麻促进尿液分泌的作用可能主要通过其中的异槲皮苷、金丝桃苷、芦丁以及绿原酸等黄酮或多酚相互作用实现的,进而起到降压作用。另外,无论6周的慢性血压调节实验还是急性毒性实验均表明罗布麻对大鼠无毒害作用。本实验可以为罗布麻降压成分分离、降压成分之间的相互作用及其机制的研究提供实验基础,也可以为罗布麻作为降压保健食品的开发、应用以及精深加工提供实验依据。更多还原

【Abstract】 Apocynum tea as experimental material and SHR as experimental animals, the effect and mechanism of blood pressure regulation of Apocynum venetum was studied. The results showed that the aqueous extracts of Apocynum venetum induced antihypertensive effect in SHR and the time-effect curve showed first increased then decreased characteristics. However, the antihypertensive effect of Apocynum venetum was slow and the first increased then decreased curve wasn’t significant until the third week. Five hours after administration, the antihypertensive effect could be observed and till 8 hours the system blood pressure was lowest. Chronic antihypertensive experiment for 6 weeks showed Apocynum venetum could induce antihypertensive effect slowly. The significant and stable decrease, about 15 mmHg, of system blood pressure was showed after three weeks. Meanwhile, Apocynum yenetum treatment for 6 weeks, no significant effect on SHR’s heart rate and blood fat, etc, had been showed, but significant diuretic effect, and urinary Na+, K+, Cl" increase had been showed. Therefore, this result showed that the antihypertensive effect of Apocynum venetum might be throught its diuretic mechanism.Apocynum venetum leaves as experimental material and wistar rats as experimental animals, the acute diuretic activity of Apocynum venetum was investigated. The results showed that in the case of urinary load, the aqueous extract of Apocynum venetum could promote the secretion of rats’urine and the urine output was increased significantly after 6 or 8 hours after oral administration. Meanwhile, the secretion of K+、Na+、Cl-were also increased with increasing doses. The time of diuretic was coinfident with that of antihypertensive phase and indicated that the antihypertensive effect of Apocynum venetum might be throught its diuretic mechanism.Using the traditional method, the effective fractions were isolated and 6 fractions were achieved, including ethanol extract fraction (EF), ethanol residue fraction (ER), n-hexane fraction (nHF), ethyl acetate fraction (EAF), n-butanol fraction (nBF) and parts of the water fraction (WF). Six fractions as experimental material and wistar rats as experimental animals, the acute diuretic activity of Apocynum venetum was studied. The result showed that the EF played a major role in promoting the urine and urine electrolytes K+, Na+, Cl’secretion in wistar rats. Among them, the nBF isolated from EF played a major role in promoting the urine secretion and urine Na+ secretion, while the WF isolated from EF played a major role in promoting the urine secretion and urine K+ and Cl- secretion.By correlation analysis, total phenols and total flavonoids of Apocynum venetum and diuretic index showed a significant positive correlation (r= 0.886, p< 0.01; r= 0.882, p< 0.01), respectivly. Among them, isoquercitrin (r=0.747, p<0.01), hyperoside (r=0.758, p< 0.01), rutin (r=0.793, p< 0.01) and chlorogenic acid (r=0.650, p< 0.05) were all showed a significant positive correlation with diuretic index, respectivly Therefore, Apocynum venetum maight be mainly through the interaction of isoquercitrin, hyperoside, rutin and chlorogenic acid and other flavonoids or polyphenol to promote urine secretion, then to decreased the blood pressure of wistar rats.In addition, not only the six weeks of chronic blood pressure regulating experiment but also the acute toxicity experiment showed no toxic effects on the rats.This experiment can provide the experimental basis for the studies of the separation of antihypertisive component, the interaction between the components and its mechanism of Apocynum venetum and it can also provide experimental basis for the development, use and intensive processing of Apocynum venetum as antihypertisive health food.更多还原