白芷中四种线型呋喃香豆素类成分药理作用研究

研究了白芷中异欧前胡素、欧前胡素、水合氧化前胡素、白当归素等4种主要线型呋喃香豆素类成分的药理作用。分别采用热板法、醋酸扭体法观察镇痛活性;家兔离体回肠法观察解痉活性;MTT法观察抗肿瘤活性。发现异欧前胡素、欧前胡素具有明显的镇痛作用,能明显抑制热板、醋酸所致小鼠疼痛,为白芷镇痛的活性成分;异欧前胡素、欧前胡素、水合氧化前胡素均能明显缓解BaCl2所致兔肠平滑肌痉挛,为白芷解痉的活性成分;异欧前胡素、水合氧化前胡素具有显著抗肿瘤作用,对HL-60、P388、HELA、A549等细胞株的生长均有明显抑制作用。     

体循环肠灌流法研究红禾麻提取物在类风湿性关节炎大鼠与正常大鼠体内的肠吸收差异

比较红禾麻提取物在AA大鼠与正常大鼠体内的肠吸收差异。实验采用体循环肠灌流法,建立大鼠RA模型,应用UPLC-MS/MS检测肠灌流液中新绿原酸、绿原酸、隐绿原酸、芦丁、异槲皮苷、槲皮苷、山奈酚-3-O-芸香糖苷、木犀草苷的含量,探究各成分在不同因素(pH值、药物浓度、肠段、胆汁和P-gp抑制剂)下的肠吸收特性。结果表明,槲皮苷的吸收方式为主动转运,其余7个成分的吸收方式为被动扩散。除绿原酸、隐绿原酸外,正常状态下各成分以回肠吸收最好,病理状态下以十二指肠吸收最好,推测药物吸收的特定部位会受疾病状态的影响而发生改变。各成分的吸收均受pH、胆汁和P-gp的影响,其中,槲皮苷可能是P-gp的底物。RA能影响红禾麻提取物在大鼠体内的肠吸收,其作用机制尚需进一步研究。     

HPLC法测定明党参组织培养物和栽培品中香豆素成分的含量

采用高效液相色谱法同时测定明党参组培和栽培品中7-羟基香豆素、花椒毒酚、欧前胡素和珊瑚菜内酯4种香豆素成分的含量。Agilent-C18色谱柱(250 mm×4.6 mm,5μm);流动相为乙腈—水溶液梯度洗脱,流速1.0 mL/min,柱温30℃;检测波长为314 nm,进样量为10μL。实验结果表明,栽培明党参的根皮4种香豆素成分7-羟基香豆素、花椒毒酚、欧前胡素、珊瑚菜内酯的含量普遍偏高,分别为5.8970、1.2710、0.0301、0.9236mg/g,明党参愈伤组织诱导根中7-羟基香豆素、花椒毒酚含量较高分别为3.7939、0.8384 mg/g;该方法简便、快速、具有良好的重现性,可用于明党参组培和栽培品中香豆素成分的含量测定。     

离体外翻肠囊法研究白及提取物中6种成分的肠吸收特性

为研究白及提取物中4-(葡萄糖氧基)-肉桂酸葡萄糖氧基苄酯(B12)、2-异丁基苹果酸(B6)、1-[4-(葡萄糖氧)苄基]-2-异丁基苹果酸酯(B17)、1,4-二[4-(葡萄糖氧)苄基]-2-异丁基苹果酸酯(B14)、二氢菲1(B19)和1,4-二[4-(葡萄糖氧)苄基]-2-异丁基苹果酸酯-2-[4-O-肉桂酰基-6-O-乙酰基]葡萄糖苷(B23)6个成分在大鼠小肠中的吸收动力学特性。实验采用大鼠离体外翻肠囊模型考察各成分在不同浓度、不同肠段的吸收特性,建立超高效液相色谱-三重四极杆串联质谱联用仪(UPLC-MS/MS)法测定各成分含量,计算累计吸收量和吸收速率常数。结果表明,除B6成分的低浓度外,各成分在不同浓度、不同肠段下均表现为线性吸收,其回归相关系数(R)均达到0.9以上,符合一级吸收速率,且吸收速率常数随着浓度的增加而增加,提示各成分吸收机制为被动吸收;在同一浓度下不同肠段的总体吸收趋势为十二指肠的吸收要大于回肠、结肠和空肠。综上,白及提取物中6种成分在小肠中均有吸收,但小肠对各成分的吸收具有选择性。本研究可为白及提取物的药物临床开发,确定药物剂型方面提供了一定的实验参考。     

温肾咳喘片主要成分对HepG2细胞中CYP相关基因表达的影响

观察温肾咳喘片组方中5种主要单体成分甘草酸、厚朴酚、和厚朴酚、蛇床子素和 欧前胡素对细胞色素P450(cytochrome P450, CYP) 1A2,2D6,2E1和3A4基因表达的影 响. 采用实时荧光定量PCR技术检测HepG2细胞中药物处理后各CYP mRNA的表达.厚朴酚 、和厚朴酚、蛇床子素和欧前胡素在不同浓度均能明显的诱导CYP2E1和CYP3A4,同时欧 前胡素也能诱导CYP1A2的表达,而甘草酸、厚朴酚、和厚朴酚、蛇床子素和欧前胡素在 不同浓度对CYP2D6的表达均具有较弱的抑制作用.甘草酸、厚朴酚、和厚朴酚、蛇床子 素和欧前胡素能明显影响CYP1A2、2D6、2E1或3A4的表达.此研究为中西药物代谢性相互 作用及毒理学的研究提供实验依据.     

基于大鼠在体肠灌流模型研究白及有效部位在肠道的可吸收及代谢成分

为了考查白及有效部位在肠道的可吸收成分及其代谢特征。基于在体肠灌流模型,采用超高效液相色谱-四极杆-飞行时间质谱仪(UPLC-Q-TOF/MS)对收集到的健康SD大鼠循环肠灌流液、血清、胆汁进行分析检测,并结合对照品、质谱碎片信息和Masslynx V4.1工作站中的Single Mass Analysis功能,初步推测吸收和代谢产物的结构式。在大鼠血清和胆汁中,初步鉴定出1,4-二[4-(葡萄糖氧)苄基]-2-异丁基苹果酸、4-(葡萄糖氧)苄基]-2-异丁基苹果酸酯、α-异丁基苹果酸酯原型产物。在大鼠循环肠灌流液、血清和胆汁中,共鉴定出4-(葡萄糖氧)苄基]-2-异丁基苹果酸酯的脱糖后硫酸化代谢产物和二氢菲5的葡萄糖醛酸化代谢产物,其代谢产物主要生水解和葡萄糖醛酸化反应。该方法初步探究了白及有效部位在大鼠循环肠灌流液中可吸收成分和代谢特征,为阐释白及药材的药效物质基础提供实验依据。     

明党参根皮超临界萃取部位化学成分研究

采用超临界CO2萃取、柱层析、重结晶等方法,从明党参根皮部位分离得到9个化合物。经理化方法和波谱分析鉴定为二十五烷酸(1)、二十七烷醇(2)、β-谷甾醇(3)、豆甾醇(4)、异欧前胡素(5)、欧前胡素(6)、花椒毒酚(7)、珊瑚菜内酯(8)和5-羟基-8-甲氧基补骨脂素(9)。化合物5～7为首次从明党参中分离得到,其余化合物均为首次从该植物根皮中分离得到。     

法罗培南在大鼠肠道吸收部位的初步研究

目的:研究法罗培南在大鼠各肠段的吸收率,以确定最佳吸收部位,为制定合理的药物制剂提供科学依据.方法:采用大鼠在体肠循环法,各肠段区间如下:十二指肠段自幽门1cm处开始;空肠段离幽门15cm处开始;回肠段离盲肠上行20 cm处开始:结肠段从盲肠后段开始.各肠段取10 cm左右,将所取肠段两端开口、插管并结扎,插管与恒流泵连接.形成各自的回路.用HPLC法梯度洗脱测定法罗培南的浓度,依据药物在肠段中回流2小时后的减少量来确定各肠段法罗培南的吸收量.结果:法罗培南在大鼠各肠段吸收率平均值为十二指肠6.91±3.08%;空肠5.66±2.29%;回肠9.62±4.08%;结肠4.65±1.29%.稳定性实验、精密度实验、回收率实验的RSD分别为0.48%、0.234%和2.01%.结论:法罗培南在各肠段均有吸收,吸收率按回肠、十二指肠、空肠、结肠顺序依次降低.     

肠缺血-再灌流大鼠血浆二胺氧化酶活性的变化与肠损伤的关系

观察并探讨了肠缺血 -再灌流大鼠血浆二胺氧化酶 (DAO)活性的变化规律及其与肠损伤相关指标变化的关系。结果显示 ,肠缺血 -再灌流过程中血浆DAO活性呈双峰升高 :第一峰在肠缺血期 ,时相上早于血浆内毒素 (LPS)和D -乳酸的升高 ;第二峰在再灌流后 2h ,在肠损伤相关指标变化的峰值之后。结果提示 ,肠粘膜上皮细胞和 (或 )肠屏障受到缺血和再灌流二次损伤的打击 ;血浆DAO活性作为反映肠损伤的指标特异性强、灵敏度高 ,在临床上对病程判断及并发症的防治有一定的指导意义。     

肠缺血-再灌流大鼠血浆二胺氧化酶活性的变化与肠损伤的关系

观察并探讨了肠缺血 -再灌流大鼠血浆二胺氧化酶 (DAO)活性的变化规律及其与肠损伤相关指标变化的关系。结果显示 ,肠缺血 -再灌流过程中血浆DAO活性呈双峰升高 :第一峰在肠缺血期 ,时相上早于血浆内毒素 (LPS)和D -乳酸的升高 ;第二峰在再灌流后 2h ,在肠损伤相关指标变化的峰值之后。结果提示 ,肠粘膜上皮细胞和 (或 )肠屏障受到缺血和再灌流二次损伤的打击 ;血浆DAO活性作为反映肠损伤的指标特异性强、灵敏度高 ,在临床上对病程判断及并发症的防治有一定的指导意义。     

Monoterpenoid furanocoumarin lactones from clausena anisata

A reinvestigation of Clausena anisata has yielded imperatorin, xanthotoxol, lansamide-I and three new furanocoumarin lactone derivatives: indicolactone, anisolactone and 2′,3′-epoxyanisolactone. The structures of these compounds have been elucidated by a combination of spectroscopic and chemical methods.     

Water absorption and bicarbonate secretion in the intestine of the sea bream are regulated by transmembrane and soluble adenylyl cyclase stimulation

In the marine fish intestine luminal, HCO₃ ^? can remove divalent ions (calcium and magnesium) by precipitation in the form of carbonate aggregates. The process of epithelial HCO₃ ^? secretion is under endocrine control, therefore, in this study we aimed to characterize the involvement of transmembrane (tmACs) and soluble (sACs) adenylyl cyclases on the regulation of bicarbonate secretion (BCS) and water absorption in the intestine of the sea bream (Sparus aurata). We observed that all sections of sea bream intestine are able to secrete bicarbonate as measured by pH?CStat in Ussing chambers. In addition, gut sac preparations reveal net water absorption in all segments of the intestine, with significantly higher absorption rates in the anterior intestine that in the rectum. BCS and water absorption are positively correlated in all regions of the sea bream intestinal tract. Furthermore, stimulation of tmACs (10???M FK?+?500???M IBMX) causes a significant decrease in BCS, bulk water absorption and short circuit current (Isc) in a region dependent manner. In turn, stimulation of sACs with elevated HCO₃ ^? results in a significant increase in BCS, and bulk water absorption in the anterior intestine, an action completely reversed by the sAC inhibitor KH7 (200???M). Overall, the results reveal a functional relationship between BCS and water absorption in marine fish intestine and modulation by tmACs and sAC. In light of the present observations, it is hypothesized that the endocrine effects on intestinal BCS and water absorption mediated by tmACs are locally and reciprocally modulated by the action of sACs in the fish enterocyte, thus fine-tuning the process of carbonate aggregate production in the intestinal lumen.     

Intestinal maturation: The effect of glucocorticoids on in vivo net magnesium and calcium transport in the rat

We investigated with an $\text{in vivo}$ single pass perfusion technique, the effect of glucocorticoids on net magnesium and calcium absorption from the small and large intestine of suckling and adolescent rats. In control rats, rates of net magnesium and calcium absorption were several fold greater in both small and large intestinal segments of suckling rats compared to corresponding rates in segments of adolescent rats. Methylprednisolone 30 mg/kg body weight daily for three days, suppressed significantly net magnesium and calcium absorption from the small and large intestinal segments of suckling rats only. Methylprednisolone had no effect on either net magnesium or calcium absorption in adolescent rats. The mechanism(s) responsible for the observed decrease in net magnesium and calcium absorption in the suckling period by glucocorticoids are discussed.     

Mechanism of action of ATP on intestinal epithelial cells: Cyclic AMP-mediated stimulation of active ion transport

ATP, ADP and AMP but not adenosine increased cyclic AMP in dispersed enterocytes prepared from guinea pig small intestine. This action of ATP was augmented by IBMX and was reproduced by App(NH)p or App(CH₂)p. ATP also increased the formation of cyclic [¹⁴C]AMP in enterocytes that had been preincubated with [¹⁴C]adenine. Gpp(NH)p and NaF each caused persistent activation of adenylate cyclase in plasma membranes from enterocytes and ATP caused significant augmentation of this persistent activation. In addition to increasing cellular cyclic AMP and agumenting Gpp(NH)p and NaF-stimulated persistent activation of adenylate cyclase, ATP increased the I_sc across mounted strips of small intestine and inhibited net absorption of fluid and electrolytes in segments of everted small intestine. These results indicate that intestinal epithelial cells possess a receptor that interacts with ATP and other adenine nucleotides and that receptor occupation by ATP causes activation of adenylate cyclase, increased cyclic AMP and changes in active ion transport across intestinal mucosa.     

Marmelene,an alkaloid,and other components of unripe fruits of Aegle Marmelos

From the unripe fruits of Aegle marmelos, a new alkaloid named marmeline was isolated and identified as N-2-hydroxy-2-[4-(3′,3′-dimethylallyloxy)phenyl]ethyl cinnamide. Aegline, imperatorin, alloimperatorin and xanthotoxol were also present.     

In situ absorption of aflatoxins in rat small intestine

To evaluate the rate at which the four main aflatoxins (aflatoxins B₁, B₂, G₁ and G₂) are able to cross the luminal membrane of the rat small intestine, a study about intestinal absorption kinetics of these mycotoxins has been made. In situ results obtained showed that the absorption of aflatoxins in rat small intestine is a very fast process that follows first-order kinetics, with an absorption rate constant (k _a ) of 5.84±0.05 (aflatoxin B₁), 4.06±0.09 (aflatoxin B₂), 2.09±0.03 (aflatoxin G₁) and 1.58±0.04 (aflatoxin G₂) h^–1, respectively.     

Biotransformation of isoimperatorin and imperatorin by Glomerella cingulata and β-secretase inhibitory activity

Biotransformation studies conducted on the furanocoumarins isoimperatorin (1) and imperatorin (3) have revealed that 1 was metabolized by Glomerella cingulata to give the corresponding reduced acid, 6,7-furano-5-prenyloxy hydrocoumaric acid (2), and 3 was transformed by G. cingulata to give the dealkylated metabolite, xanthotoxol (4) in high yields (83% and 81%), respectively. The structures of the new compound 2 have been established on the basis of spectral data. The metabolites 2 and 4 were tested for the β-secretase (BACE1) inhibitory activity in vitro, and metabolite 2 slightly inhibited the β-secretase activity with an IC₅₀ value of 185.6 ± 6.8 μM. The metabolite 4 was less potent activity than compounds 1–3. In addition, methyl ester (2Me), methyl ether (2a) and methyl ester and ether (2aMe) of 2 were synthesized, and investigated for the ability to inhibit β-secretase. Compound 2aMe exhibited the best β-secretase inhibitory activity at the IC₅₀ value 16.2 ± 1.2 μM and found to be the 2aMe showed competitive mode of inhibition against β-secretase with K_i value 11.3 ± 2.8 μM.     

Circadian Variations in Exsorptive Transport: In Situ Intestinal Perfusion Data and In Vivo Relevance

The circadian timing system (CTS) governs the 24-h rhythm of the organism and, hence, also main pathways responsible for drug pharmacokinetics. P-glycoprotein (P-gp) is a drug transporter that plays a pivotal role in drug absorption, distribution, and elimination, and temporal changes in its activity may affect input, output, activity, and toxicity profile of drugs. In the current study, the influence of different circadian stages on the overall intestinal permeability (P_eff) of the P-gp substrates talinolol and losartan was evaluated in in situ intestinal perfusion studies in rats. Additionally, in vivo studies in rats were performed by employing the P-gp probe talinolol during the day (nonactive) and night (active) period in rats. Effective intestinal permeabilities of talinolol and losartan were smaller in studies performed during the night (p?<?.05), indicating that P-gp–dependent intestinal secretion is greater during the nighttime activity span than daytime rest span of the animals. P-gp modulators vinblastine and PSC833 led to a significant decrease of talinolol and losartan exsorption in the intestinal segments as compared with control groups. Strikingly, the permeability-enhancing effect of vinblastine and PSC833 was higher with night perfusions, for both talinolol and losartan. In vivo studies performed with talinolol revealed—consistent with the in situ studies (P_eff day?>?night)—a day vs. night difference in the oral availability of talinolol in the group of male rats in terms of the area under the curve (AUC) data (AUC_day?>?AUC_night). The P-gp modulator vinblastine significantly increased talinolol AUC_day (p?<?.05), whereas only a weak vinblastine effect was seen in night. According to the in situ data, the functional activity of P-gp was regulated by the CTS in jejunum and ileum, which are major intestinal segments for energy-dependent efflux. In conclusion, circadian rhythms may affect carrier-mediated active efflux and play a role in the absorption process. In addition to daily rhythms in P-gp activity in rat intestine, the in vivo studies indicate that absorption-, distribution-, metabolism-, and elimination-relevant rhythms may be involved in the circadian kinetics of the drug, besides transporter-dependent efflux, such well-known aspects as metabolic or renal clearance or motility. Since this also holds true for a potentially interacting second compound (modulator), modulator effects should be evaluated carefully in transporter related drug-drug interactions. (Author correspondence: aokyar@istanbul.edu.tr)     

Human intestine epithelial cell acetyl- and butyrylcholinesterase

The epithelial cells of the human intestine exhibit a cholinesterase activity which is restricted to the apex of the villi. This activity displays a maximum in the colon and a minimum in the jejunum. Contrary to most of the studied vertebrates, the human cells present both acetylcholinesterase and butyrylcholinesterase activities, acetylcholinesterase being predominant in all the intestinal segments: duodenum, jejunum, ileum and colon. Like in the other vertebrates, only globular forms are identified by sucrose gradient centrifugation. However, the simultaneous presence, on the one hand of three globular forms (G₁, G₂ and G₄) and, on the other hand of soluble as well as detergent-soluble molecular species seems to be a particular feature of the human cells.Abbreviations ChE Cholinesterases - AChE Acetylcholinesterase - BuChE Butyrylcholinesterase