基于大鼠原位肠-肝血管灌流模型研究甘草酸的代谢

目的研究甘草酸在大鼠体内的肠、肝中的生物转化。方法建立大鼠原位肠-肝血管灌流模型,采用LC-MS/MS方法测定灌流液中的甘草酸和甘草次酸。结果甘草酸在单向肠-肝血管灌流模型中稳态肠提取率和稳态肝提取率分别为(4.2±0.6)%和(28.0±3.0)%,灌流液中未发现代谢物甘草次酸;原位循环肠血管灌流模型中甘草酸的一级吸收速率常数为(0.33±0.06)min-1;甘草酸在大鼠十二指肠给药后,灌流液中主要活性代谢产物为甘草次酸,同时肠腔液也存在大量甘草次酸。结论甘草酸的首过效应明显,口服后其主要被肠道菌群或肝细胞代谢,在肠粘膜细胞仅少量代谢。大鼠原位肠-肝血管灌流模型适用于甘草酸的药动学研究。     

四妙勇安汤不同配伍对其主要活性成分绿原酸吸收的影响

目的 考察分析四妙勇安汤不同配伍对其主要有效活性成分绿原酸的吸收影响.方法 四妙勇安汤不同配伍后各种样品水煎液大鼠十二指肠给药,肠-肝灌流模型循环灌流2 h后采用LC/MS分析灌流液中主要活性成分绿原酸的浓度.结果 四妙勇安汤不同配伍对其主要活性成分绿原酸的吸收有明显影响,金银花水煎液、金归(金银花加当归)水煎液、金玄...     

2-苯甲酰肼叉-1,3-二噻茂烷在大鼠原位灌流肝中的代谢动力学

采用反相高压液相色谱的三内标三波长切换技术对不同剂量的农药2-苯甲酰肼叉-1.3二噻茂烷在大鼠原位灌流肝中的代谢动力学进行了研究.结果表明,该农药经门静脉进入大鼠原位灌流肝后,很快分布于肝脏中,而在灌流肝中的消除过程较缓慢。随着给药剂量的增加,大鼠肝灌流液中各种代谢产物的生成量也逐渐增加,尤以肼叉1.3-二噻茂烷和苯甲酸生成量的增加更为显著.可见,该农药在大鼠原位灌流肝中的主要代谢途径为水解作用。     

高效液相色谱-四级杆飞行时间串联质谱法分析瑞香素在大鼠肠壁的代谢产物

研究瑞香素在大鼠肠壁产生的代谢产物。采用大鼠在体肠灌流模型,分别收集瑞香素0～2 h内的十二指肠、空肠、回肠和结肠灌流液,以液相色谱-四级杆飞行时间串联质谱法分析肠道灌流液中瑞香素的代谢产物。在大鼠十二指肠、空肠、回肠灌流液中共发现瑞香素原形药物和4个代谢产物,分别推测为瑞香素-7-硫酸酯、瑞香素-8-硫酸酯、瑞香素-7-葡糖醛酸结合物和瑞香素-8-葡糖醛酸结合物;而在结肠灌流液中未发现代谢产物。在瑞香素的4个代谢产物中,瑞香素-7-硫酸酯和瑞香素-8-硫酸酯(m/z 257)为首次发现的瑞香素在大鼠体内的Ⅱ相代谢产物,揭示了其在大鼠体内代谢的新途径。     

T2毒素在灌流大鼠肠肝中的首过效应和代谢动力学

建立并用大鼠在体肠-肝灌流标本研究了T2毒素在大鼠肠肝中的首过效应和代谢转化动力学,T2毒素在大鼠肠肝中的主要代谢产物是HT2,3′-OHHT2和其葡萄糖醛酸结合物,T2毒素具有显著的肠肝首过效应,当毒素(42μg·ml~(-1))由上肠系膜动脉恒速单次灌流(8 ml·min~(-1))肠-肝标本时,穗态肝、肠抽提率分别为0.978和0.454,总有效清除率为7.91 ml·min~(-1),T2毒素在循环灌流大鼠肠-肝标本中的消除半衰期为6.5min,主要代谢产物HT2,3′-OHHT2的生成半衰期分别为8.5和38.5 min,结果表明,T2毒素经消化道中毒后,在肠和肝的首过代谢下能很快地转化为产物,因此,毒素在体内的毒效作用主要由其代谢产物表现出来。     

盐酸三环哌酯在大鼠体内外的代谢

用大鼠原位灌流肝脏、整体实验和大鼠肝脏微粒体酶制备对盐酸三环哌酯(TCPN)的代谢转化进行了研究。结果经大鼠原位肝脏灌流后,灌流液经提取和HPLC分离制备,得到两个代谢产物。经MS,NMR,IR和UV鉴定,证明产物I是TCPN氮上脱甲基的产物,产物I是TCPN苯环羟化的产物。从大鼠igTCPN后的尿中及在TCPN和肝脏微粒体的温孵液中均得到产物I和产物II,提示TCPN的代谢转化主要由大鼠肝脏微粒体酶催化。以[³H]QNB为配体对TCPN及其代谢产物的受体结合活性进行了研究,结果表明产物I和产物I与M受体的亲和力分别是TCPN的1/20和1/50。     

绿原酸、咖啡酸和阿魏酸对补体旁路激活致内皮细胞炎症相关分子表达的干预

目的研究绿原酸及其代谢产物咖啡酸和阿魏酸对补体旁路激活导致人微血管内皮细胞炎症反应相关分子表达的干预作用。方法采用眼镜蛇毒因子激活人血清补体旁路,将补体旁路激活产物作用于人微血管内皮细胞,分别取不同时间点的细胞培养上清,采用ELISA方法检测ICAM-1、IL-6、IL-8、t-PA、PAI-1的含量;采用不同浓度的绿原酸、咖啡酸、阿魏酸预处理内皮细胞,然后将细胞暴露于补体旁路激活产物,检测不同时间点细胞培养上清中ICAM-1、IL-6、IL-8、t-PA、PAI-1的含量变化。结果补体旁路激活产物作用于人微血管内皮细胞后,引起ICAM-1、IL-6、IL-8、t-PA、PAI-1的表达上调。50、100、250μmol·L~(-1)的绿原酸、咖啡酸、阿魏酸对ICAM-1、IL-6、IL-8、t-PA、PAI-1的上调表达均有干预作用,其中对ICAM-1和IL-8的干预作用最明显。咖啡酸表现出最好的干预作用,其次为阿魏酸。结论一定浓度的绿原酸、咖啡酸、阿魏酸能有效抑制补体旁路激活引起的人微血管内皮细胞表达ICAM-1、IL-6、IL-8、t-PA、PAI-1的上调,提示绿原酸、咖啡酸、阿魏酸对微血管内皮细胞的炎症反应有一定的干预作用。     

T—2毒素及其代谢产物在大鼠胆汁中的排泄和肠肝循环

T-2毒素及其代谢产物的胆汁排泄和肠肝循环分别在胆管插管大鼠和大鼠肠-肝灌流标本上进行了研究。T-2毒素经门静脉注射后4hr内,染毒剂量的68±12％从插管大鼠的胆汁中排出,胆汁中主要产物是HT-2毒素(HT-2)、3′-羟基HT-2毒素(3′-OHHT-2)、3′-羟基T-2毒素(3′-OHT-2)的葡萄糖醛酸结合物。供体大鼠胆汁经固相树脂(XAD-2)小柱提取和薄层层析(TLC)分离,得到纯化的毒素代谢物的葡萄糖醛酸苷,定量后注射进入灌流大鼠肠标本和肠—肝标本的十二指肠内,在2hr的灌流过程中,注射的结合物有22％被肠道分解并重吸收,7.5％经肝脏作用后再由胆汁排出,其中主要是结合产物,由此证明了T-2毒素代谢产物肠肝循环的存在。     

离体外翻肠囊法研究蒙药塔布森-2中8个苯丙素类成分的肠吸收特性

目的：考察蒙药塔布森-2（tabson-2 decoction,TBD）中隐绿原酸、绿原酸、新绿原酸、异绿原酸C、1,5-二咖啡酰奎宁酸、咖啡酸、3-羟基肉桂酸、二氢咖啡酸8个苯丙素类成分的肠吸收动力学特性。方法：采用大鼠外翻肠囊实验,利用超高效液相色谱-三重四极杆串联质谱联用仪（UPLC-MS/MS）检测肠吸收液中8个化学成分的含量,计算各成分在各肠段的累计吸收量、吸收速率常数和表观渗透系数。结果：在同一浓度下8个成分的最佳吸收部位基本为空肠或十二指肠,吸收方式为主动转运和被动扩散相结合。结论：肠道对TBD中8个苯丙素类成分均有肠吸收,空肠和十二指肠可能是其主要吸收部位。本研究可为TBD的药物临床开发提供一定的科学依据。     

农药叶枯灵在大鼠原位灌流肝中的代谢研究

采用反相HPLC、TLC、UV、IR和MS对农药叶枯灵经大鼠原位灌流肝代谢后所形成的代谢产物进行分离和鉴定。结果表明,叶枯灵在大鼠肝脏中进行了广泛的代谢,包括S-氧化作用、水解作用、丙酮酸缩合作用和乙酰化作用,共分离鉴定出5种代谢产物。     

Chlorogenic acid exhibits anti-obesity property and improves lipid metabolism in high-fat diet-induced-obese mice

This study investigated the efficacy of chlorogenic acid on altering body fat in high-fat diet (37% calories from fat) induced-obese mice compared to caffeic acid. Caffeic acid or chlorogenic acid was supplemented with high-fat diet at 0.02% (wt/wt) dose. Both caffeic acid and chlorogenic acid significantly lowered body weight, visceral fat mass and plasma leptin and insulin levels compared to the high-fat control group. They also lowered triglyceride (in plasma, liver and heart) and cholesterol (in plasma, adipose tissue and heart) concentrations. Triglyceride content in adipose tissue was significantly lowered, whereas the plasma adiponectin level was elevated by chlorogenic acid supplementation compared to the high-fat control group. Body weight was significantly correlated with plasma leptin (r = 0.894, p < 0.01) and insulin (r = 0.496, p < 0.01) levels, respectively. Caffeic acid and chlorogenic acid significantly inhibited fatty acid synthase, 3-hydroxy-3-methylglutaryl CoA reductase and acyl-CoA:cholesterol acyltransferase activities, while they increased fatty acid β-oxidation activity and peroxisome proliferator-activated receptors α expression in the liver compared to the high-fat group. These results suggest that caffeic acid and chlorogenic acid improve body weight, lipid metabolism and obesity-related hormones levels in high-fat fed mice. Chlorogenic acid seemed to be more potent for body weight reduction and regulation of lipid metabolism than caffeic acid.     

The Spermatogenic Effect of Yacon Extract and Its Constituents and Their Inhibition Effect of Testosterone Metabolism

We screened the pharmacological effects of a 50% ethanol extract of Yacon tubers and leaves on spermatogenesis in rats. As a result, we found that Yacon tuber extracts increased sperm number and serum testosterone level in rats. It has been reported that the crude extract of Yacon tubers and leaves contain phenolic acids, such as, chlorogenic acid, ferulic acid and caffeic acid by HPLC/MS analysis. We were interested in the contributions made by phenolic acid, particularly chlorogenic acid of Yacon tuber extract to the spermatogenic activity. After administering Yacon tuber extract or chlorogenic acid to rats for 5 weeks, numbers of sperm in epididymis were increased by 34% and 20%, respectively. We also administered ferulic acid, which has been reported to be a metabolite of chlorogenic acid and a constituent of Yacon tuber extract to investigate its spermatogenic activity in rats. Yacon tuber extract and ferulic acid increased sperm numbers by 43% and 37%, respectively. And, Yacon tuber extract, and chlorogenic acid showed significantly inhibition effect of testoeterone degradation in rat liver homogenate. We considered that the spermatogenic effect of Yacon tuber extract might be related to phenolic compounds and their inhibitory effect of testosterone degradation. Yacon showed the possibility as ameliorable agents of infertility by sperm deficiency and late onset hypogonadism syndrome with low level of testosterone.     

γ-亚麻酸甲酯乳剂代谢动力学

本文应用动物全血、组织匀浆体外保温实验和大鼠离体肝脏灌流技术研究了γ-亚麻酸甲酯乳剂的代谢动力学。γ-亚麻酸甲酯在全血中迅速水解;在肝、小肠和肾中也存在代谢;离体肝灌流液中γ-亚麻酸的浓度下降与时间关系经拟合符合单指数方程,消除半衰期为13.2min,肝固有消除率为2.46ml/min.     

大鼠原位肠肝血管灌流模型的优化及完善

目的:对大鼠原位肠肝血管灌流模型的灌流液组成成分进行优化,以获取最佳灌流液配方。方法:对灌流条件进行优化,分别对Krebs-Rin-ger(K-R)液加牛血清白蛋白和甘露醇、K-R液加牛血清白蛋白和右旋糖酐T-40二者进行对比,找出最佳的灌流介质。然后对最佳的灌流介质中牛血清白蛋白的含量进行了优化。结果:K-R液加牛血清白蛋白和右旋糖酐T-40组优于K-R液加牛血清白蛋白和甘露醇组;5%牛血清白蛋白的灌流液是一个较为经济理想的灌流液。结论:在灌流介质中5%牛血清白蛋白是一个较为理想和经济的比例。     

In vitro and in vivo antioxidant properties of chlorogenic acid and caffeic acid

Dietary polyphenols are thought to be beneficial for human health as antioxidants. Coffee beans contain a common polyphenol, chlorogenic acid. Chlorogenic acid is the ester of caffeic acid and quinic acid. Although these polyphenols have received much attention, there is little evidence indicating a relationship between the effect and the rate of absorption. In this study, we focused on the beneficial effects of chlorogenic acid and caffeic acid, a major metabolite of chlorogenic acid. We carried out in vitro and in vivo experiments. In the in vitro study, caffeic acid had stronger antioxidant activity than that of chlorogenic acid. The uptake of chlorogenic acid by Caco-2 cells was much less than that of caffeic acid. The physiological importance of an orally administered compound depends on its availability for intestinal absorption and subsequent interaction with target tissues. We then used an intestinal ischemia-reperfusion model to evaluate antioxidant activities in vivo. We found that both chlorogenic acid and caffeic acid had effects on intestinal ischemia-reperfusion injury. Since caffeic acid has a stronger antioxidant activity than that of chlorogenic acid and chlorogenic acid is hydrolyzed into caffeic acid in the intestine, it is possible that caffeic acid plays a major role in the protective effect of chlorogenic acid against ischemia-reperfusion injury.     

HPLC测定炒苍耳子配方颗粒中绿原酸及咖啡酸的含量

目的建立同时测定炒苍耳子配方颗粒中绿原酸和咖啡酸的高效液相色谱法。方法采用Shim-packVP-ODS柱（250mm×4.6mm,5μm）;流动相为乙腈-0.1%磷酸水溶液（10：90）;检测波长为327nm;柱温为35℃。结果绿原酸在0.2152～1.7216μg内线性关系良好（r=0.9999）,咖啡酸在0.02296～0.1148μg内线性关系良好（r=0.9999）;绿原酸、咖啡酸平均加样回收率分别为96.39%（RSD=1.48%）、100.02%（RSD=1.81%）。结论所建立的方法简便、准确,可同时测定炒苍耳子配方颗粒中绿原酸和咖啡酸的含量。     

Montmorillonite adsorbs uric acid and increases the excretion of uric acid from the intestinal tract in mice

Objectives The aim was to evaluate the adsorbing effect of montmorillonite on uric acid, promoting diffusion of uric acid from blood to intestine, preventing absorption of uric acid in intestine and reducing uric acid level in serum. Methods The adsorbing effect of montmorillonite on uric acid was observed in vitro. The intestine and blood vessel of rats were circularly perfused with intestinal perfusate and vascular perfusate, respectively. A model of hyperuricaemia in mice was prepared by intraperitoneal injection of hypoxanthine and potassium oteracil. The concentration of uric acid was determined by the method of urate oxidase and peroxide enzyme. Key findings The results showed that different concentrations of montmorillonite could adsorb uric acid in a concentration‐dependent manner. The adsorbing effect was fast. The adsorptive rate was high in acid solution and was low in alkaline solution. When blood vessels were circularly perfused by vascular perfusate containing uric acid, the concentration of uric acid in vascular perfusate was decreased and the concentration of uric acid in intestinal perfusate was increased, suggesting that uric acid in blood vessels diffused into the intestine. When the intestine was perfused with intestinal perfusate containing uric acid, the uric acid concentration in vascular perfusate was increased, but the uric acid concentration of intestinal perfusate was decreased, suggesting that uric acid was absorbed in the intestine. The uric acid concentrations of intestinal perfusate and vascular perfusate in montmorillonite 0.5 and 1.0 g/kg groups were lower than the control group. Concentrations of uric acid in serum and urine in the montmorillonite 1 and 2 g/kg groups were lower compared with mice in the hyperuricaemic group. Conclusions The results suggested that montmorillonite adsorbed uric acid and promoted diffusion of uric acid from blood vessels to intestine, prevented absorption of uric acid in intestine and decreased uric acid level in serum.