Effect of Terminalia arjuna extract on KCl induced contractions in the rat vas deferens

Experiments were carried out to elucidate the effects of extracts from Terminalia arjuna on potassium chloride (160 mM) induced contraction in smooth muscle. The petroleum ether extract did not exhibit a response, whereas the preincubation of tissue with the alcoholic extract inhibited contraction. Experimental approaches, described here, lead to the speculation that T. arjuna may impart its action through the modulation of Ca²⁺ ions across the cellular membrane.     

莲心碱对家兔主动脉条收缩性能的影响

 目的　观察莲心碱 (liensinine,Lien)对氯化钾(KCl),去甲肾上腺素(NE)和组织胺(Hist)所致家兔主动脉条收缩的作用。并研究其对血管条依内钙性收缩和依外钙性收缩的影响。方法　离体平滑肌实验方法。结果　不同剂量Lien及维拉帕米(Ver)对KCl,NE,Hist诱导的主动脉条均呈抑制作用,并可非竞争性拮抗组胺的量效曲线,PD₂′值分别为4.31,6.89。Lien和Ver均能抑制组胺诱导的依内钙收缩,而对依外钙收缩作用较弱。结论　Lien可舒张兔主动脉条,该作用与钙离子拮抗有关,且对主动脉依内钙性收缩的敏感性大于依外钙性收缩。     

前胡对兔离体肺动脉的作用

以兔离体肺动脉环为研究对象，观察到前胡水煎剂及其石油醚提取物具有舒张肺动脉及降低肺动脉环对去甲肾上腺素和氯化钾所致收缩的反应性；其中石油醚提取物还能使去甲肾上腺素收缩肺动脉的量效曲线呈非平行右移，且最大反应降低，PD’2＝4．73±0．43。     

Effects of an aqueous extract of Terminalia arjuna on isolated rat atria and thoracic aorta

Terminalia arjuna (Combretaceae) is used traditionally in ayurveda, to treat a variety of cardiovascular disorders. The aims of this study were to characterize the positive inotropic effect of the aqueous extract of T. arjuna bark in isolated paced rat left atria and to study its effects on a vascular smooth muscle preparation, the rat thoracic aorta. The crude and semipurified aqueous extracts produced a positive inotropic effect of rat atria and the maximum contraction was comparable to that produced by isoprenaline. The positive inotropic effect of the extract was completely blocked by a β-adrenoceptor blocker, propranolol, and an uptake-1 blocker, cocaine. In precontracted aorta, the aqueous extract produced a contraction followed by relaxation. Propranolol did not block the relaxant effect of the aqueous extract. It is concluded that the positive inotropic effect of the aqueous extract was mediated via an action on β₁-adrenoceptors and was likely to be due to the release of noradrenaline from the sympathetic nerve endings. The vasorelaxant effect of the extract, however, was not mediated via an action on β₂ adrenoceptor.     

天钩降压胶囊对家兔主动脉血管条收缩反应的影响

目的:观察天钩降压胶囊对家兔主动脉条收缩反应的影响,探讨其降压作用机制.方法:将家兔离体主动脉条置于灌流肌槽中,记录天钩降压胶囊提取物对去甲肾上腺素(NE)、氯化钾(KCl)、氯化钙(CaCl2)诱导的主动脉条收缩作用的影响,以及对NE诱导的主动脉条细胞内钙及细胞外钙依赖性收缩反应的影响.结果:天钩降压胶囊1,3,5g·L-1剂量组均能使NE,CaCl2引起的主动脉条最大收缩反应降低(P＜0.01);对NE诱发主动脉条细胞内钙及细胞外钙依赖性收缩均有明显抑制(P＜0.01),对细胞外钙依赖性收缩的抑制作用更显著;对KCl引起的动脉条收缩反应无明显影响.结论:天钩降压胶囊可通过影响细胞内钙离子浓度促进血管平滑肌舒张从而发挥降压作用.其机制可能主要通过影响受体操纵的Ca2+通道(ROC),对电压依赖性Ca2+通道(PDC)作用不显著.对NE诱发主动脉条细胞外钙依赖性收缩的抑制作用优于对细胞内钙依赖性收缩的作用.     

Analysis of the mechanisms underlying the vasorelaxant action of coptisine in rat aortic rings

The aim of the present study was to evaluate the vasorelaxant effects of coptisine and its possible mechanisms in isolated rat aortic rings. Coptisine was evaluated on isolated rat aortic rings precontracted with norepinephrine (NE) and KCl. The mechanisms were evaluated in the presence or absence of specific pharmacological inhibitors. Coptisine (1 ~ 200 μM) relaxed NE (1 μM) or KCl (60 mM) induced sustained contraction with pEC(50) values of 4.49 ± 0.48 and 4.85 ± 0.57 in a concentration dependent manner. Pretreatment with coptisine (10, 50 or 100 μM) also inhibited concentration-response curves to NE and KCl. The vasorelaxant effect of coptisine was attenuated significantly by endothelium removal, and incubation with Nω-nitro-L-arginine methyl ester (L-NAME, 100 μM), methylene blue (10 μM) and indomethacin (5 μM) partially reduced the vasorelaxant effect of coptisine. In endothelium-denuded rings, the vasorelaxant effect of coptisine was reduced significantly by 4-aminopyridine (4-AP, 100 μM), but not glibenclamide (10 μM) ortetraethylammonium (TEA, 5 mM). Coptisine also reduced NE-induced transient contraction in Ca(2+)-free solution, and inhibited contraction induced by increasing external calcium in Ca(2+)-free medium plus 60 mM KCl. It was concluded that coptisine induced both endothelium-dependent and -independent relaxation in rat aortic rings. The NO-cGMP mediated pathway may be involved in the endothelium-dependent relaxation and in the activation of voltage-dependent K(+) channels, contributing in part to the endothelium-independent relaxation bycoptisine. Coptisine also blocks extracellular Ca(2+) influx by interacting with both voltage- and receptor-operated Ca(2+) channels.     

Terminalia arjuna,an ayurvedic cardiotonic,increases contractile force of rat isolated atria

The direct effects of aqueous, ethanolic, chloroform and petroleum ether extracts of Terminalia arjuna (family: Combretaceae) bark, an ayurvedic remedy for cardiovascular disorders, were studied on isolated atria of rats. The aqueous extract produced a substantial positive inotropic effect (EC₅₀ = 0.25 mg/mL) but no change in the rate. The ethanol, chloroform and petroleum ether extracts all decreased the rate of contraction. A slight increase in force was seen with ethanol and chloroform extracts. Higher concentrations of the chloroform extract had a negative inotropic effect. The ethanol extract decreased the maximum following frequency of the left atria. It is concluded that Terminalia arjuna has a significant positive inotropic property on rat atria in vitro which could contribute to its efficacy in treating cardiovascular disorders.     

Hypotensive effect in rats of hydrophilic extract from Terminalia arjuna containing tannin-related compounds

The effects of extracts containing tannin-related compounds from Terminalia arjuna, which has been used in the treatment of cardiovascular disorders by Ayurvedic physicians, on the blood pressure and heart rate of rats were examined. An aqueous extract of Terminalia arjuna produced a transient decrease in blood pressure accompanied by a slight decrease in heart rate. The hypotensive effect was observed with a fraction containing tannin-related compounds (F2) separated from the aqueous extract. The hypotensive effect of F2 was not affected by pretreatment of rats with propranolol, but was attenuated by pretreatment with atropine. The effects on blood pressure of acetylcholine, epinephrine, isoproterenol and bilateral carotid occlusion, were not affected by treatment with F2. These results suggest that an aqueous fraction of Terminalia arjuna containing tannin-related compounds has a hypotensive effect in the rat, which may be mediated by cholinergic mechanisms. © 1997 John Wiley & Sons, Ltd.     

隔山香正丁醇部位对大鼠胸主动脉的舒张作用及机制的影响

目的:研究隔山香(Lemonfragrant Angelica Root,LAR)正丁醇部位对大鼠胸主动脉环的舒张作用,并探讨其可能的作用机制。方法:采用离体大鼠胸主动脉血管环灌流方法,考察0.34,0.65,1.22 g·L-1隔山香正丁醇部位对氯化钾(KCl)和去甲肾上腺素(norepinephrine,NE)预收缩的血管环张力的影响。在无Ca2+Kreb’s液中,考察0.34,0.65,1.22 g·L-1隔山香正丁醇部位对氯化钙(Ca Cl2)量效曲线的影响和NE预收缩的血管环张力的影响。激光共聚焦扫描显微镜检测平滑肌细胞内[Ca2+]i的变化。结果:隔山香正丁醇部位对KCl和NE预收缩的内皮完整和去除内皮血管环均具有浓度依赖性的舒张作用(P0.01),并且去除内皮后的舒张作用未受影响;无Ca2+条件下,隔山香正丁醇部位能使Ca Cl2,NE预收缩强度显著性降低(P0.01)。激光共聚焦扫描显微镜下,隔山香正丁醇部位(1.22 g·L-1)能抑制KCl,NE和毒胡萝卜素(thapsigargin,TG)引起的平滑肌细胞内[Ca2+]i升高。结论:隔山香正丁醇部位对大鼠胸主动脉血管有一定的舒张作用,可能通过抑制外钙内流和内钙释放发挥作用。本实验为隔山香水蒸气蒸馏后煎煮入药的成药制备工艺和水溶性药效指标成分的分离提供了依据。     

砂仁提取液对离体家兔主动脉条收缩性能的影响

目的研究砂仁提取液对兔离体胸主动脉血管条的作用。方法采用家兔离体胸主动脉血管条,以不同浓度去甲肾上腺素(NE)、氯化钾(KC l)为刺激剂,观察砂仁提取液对其量效曲线的影响;以NE为血管收缩刺激剂,观察砂仁提取液对内钙释放与外钙内流的影响。结果砂仁提取液使NE与KC l的量效曲线明显右移,最大反应性降低,对KC l量效曲线的抑制作用强于NE;在无钙Kerbs液中,砂仁提取液浓度依赖性抑制NE诱导的内钙释放所诱导的血管收缩反应,对复钙后NE所致的血管持续收缩具有抑制作用的趋势。结论砂仁提取液可舒张兔主动脉条,该作用可能与钙离子拮抗有关,且对主动脉依内钙性收缩的敏感性大于依外钙性收缩;对电压依赖钙通道的拮抗作用强于受体操纵的钙通道。     

Ligusticum wallichi-induced vasorelaxation mediated by mitogen-activated protein kinase in rat aortic smooth muscle

Traditional herbal medicines have been widely used for the treatment of cardiovascular disorders in oriental countries. To determine the effects of Ch1LW, a chloroform extract of Ligusticum wallichi, on the vascular system, we studied changes in rat aortic smooth muscle in terms of magnitude of contraction and the activity of mitogen-activated protein kinases (MAPKs). Ch1LW inhibited the muscle contraction induced by norepinephrine (NE) in aortic strips. Ch1LW also abolished Ca²⁺-independent contraction evoked by 12-deoxyphorbol 13-isobutyrate in Ca²⁺-free medium containing 1 mM EGTA. Furthermore, western blotting analysis using phosphorylated MAPK antibodies showed that NE increased the activity of both extracellular signal-regulated kinase 1/2 (ERK1/2) and p38 MAPK, which were inhibited by PD98059 and SB203580, blockers of ERK1/2 and p38 MAPK, respectively. Furthermore, treatment with Ch1LW significantly abolished NE-mediated activation of ERK1/2, whereas the activity of p38 MAPK was not affected by the extract. These results suggest that Ch1LW induces vasorelaxation in rat aortic smooth muscle, which may be mediated by the inhibition of ERK1/2 pathway, but not p38 MAPK.     

藏药1号水提液对大鼠离体胸主动脉条收缩作用的影响

目的：通过观察藏药1号水提液对大鼠离体胸动脉条收缩作用的影响研究其降压机制。方法：观察藏药1号水提液(6mg／mL)和维拉帕米(Ver0.013mg／mL)对高K^ 液引起的主动脉条收缩的时效影响，对KCl，NE及CaCl2引起的大鼠主动脉条收缩的量效曲线的影响，以及对NE引起的依赖于细胞内钙及细胞外钙的收缩的影响。结果：藏药1号水提液抑制高K^ 液引起的主动脉收缩；且可使KCl、NE及CaCl2引起的大鼠主动脉条收缩的量效曲线非平行右移，最大效应降低，呈非竞争性拮抗作用：与维拉帕米相似，对NE引起的依赖于细胞内钙及细胞外钙的收缩均有抑制作用。结论：提示藏药1号的降压机制与钙离子通道拮抗剂一致。     

Inhibitory effect of rehmaionoside B,a constituent of rehmaniae radix,on isolated bladder and urethral smooth muscle of mice

We have investigated the effects of rehmaionoside B and other constituents of Rehmaniae radix on bladder and urethral smooth muscle strips of mice. Of the five constituents investigated, rehmaionoside B (1 mg/mL) most effectively inhibited the contraction induced by noradrenaline (10 μg/mL) in urethral smooth muscle. These constituents, especially rehmaionoside B, not only inhibited the spontaneous contraction but slightly relaxed the normal tone of the bladder smooth muscle. The relaxation induced by rehmaionoside B (0.1 mg/mL) corresponded to 26.4% of the isoproterenol (1 μg/mL) response. Rehmaionoside B also inhibited the PGF_2α-induced spontaneous contraction of the bladder. The treatment with rehmaionoside B significantly inhibited arachidonic acid-induced contraction of the bladder. This response was similar to that induced by indomethacin. Rehmaionoside B inhibited both urethral and bladder smooth muscles, which may affect micturition. The effect of rehmaionoside B on the bladder was an indomethacin-like action.     

野马追对豚鼠离体气管平滑肌收缩功能的影响

目的 :研究野马追对豚鼠离体气管平滑肌收缩功能的影响。方法 :离体豚鼠气管螺旋条上建立不同浓度野马追孵育时各致痉剂的量效曲线 ,观察野马追对各致痉剂引起收缩的影响。结果 :野马追对豚鼠离体气管平滑肌的静息张力和乙酰胆碱、组胺、氯化钙、氯化钾、氯化钡所致的收缩都有抑制作用 ,使以上各致痉剂的量效曲线非平行右移 ,最大效应降低 ,其强度依次为BaCl2>KCl>CaCl2 >His >Ach ,并明显抑制乙酰胆碱所致的外钙内流引起的收缩 ,以上作用均具剂量依赖性。结论 :野马追为以上各激动剂的非竞争性拮抗剂 ,其作用机制可能与钙通道的阻滞作用有关。     

拳参正丁醇提取液对家兔胸主动脉条收缩的影响

目的:研究拳参正丁醇提取液(PBNA)对家兔离体胸主动脉条的作用。方法:采用家兔离体胸主动脉条,高钾去极化后,以不同浓度CaCl2为刺激剂,观察PBNA对其量-效曲线的影响;以NE为血管收缩刺激剂,观察PBNA对内钙释放与外钙内流的影响。结果:(1)低剂量PBNA(0.1mg/ml)可抑制高钾去极化引起的动脉条收缩,使CaCl2量-效曲线右移,最大反应性降低,高剂量PBNA(0.4mg/ml)可增强高钾去极化引起的动脉条收缩;(2)低剂量的PBNA抑制NE诱导的内钙释放所致的血管收缩反应,而高剂量的PBNA增强NE诱导的内钙释放所致的血管收缩反应;各剂量的PBNA对复钙后NE所致的血管收缩作用具有抑制趋势。结论:不同浓度的PBNA通过抑制或促进平滑肌细胞膜电压依赖Ca2 通道而对家兔主动脉条的收缩起双重效应,PBNA对受体操纵的Ca2 通道也具有一定的抑制作用,对K 通道的开放有一定的促进作用。     

诃子醇提物对动物胃肠运动和血清胃动素含量的影响

目的: 研究诃子醇提物对动物胃肠运动和血清胃动素含量的影响。 方法: 将实验动物随机分为空白对照组、吗丁啉（小鼠0.005 g·kg^-1,大鼠0.003 g·kg^-1）组,诃子提取物高、中、低剂量组（小鼠3.5,1.75,0.875 g·kg^-1,大鼠2.4,1.2,0.6 g·kg^-1）,按10 mL·kg^-1给药,采用小鼠在体胃肠运动实验、放免法检测大鼠血清胃动素含量和家兔离体肠平滑肌运动实验,观察诃子提取物对正常小鼠胃排空、小肠推进运动和大鼠血清胃动素含量以及家兔离体肠平滑肌收缩的影响。 结果: 诃子提取物高、中剂量对正常小鼠胃排空和小肠推进运动有显著抑制作用,可以降低大鼠血清胃动素的含量,对家兔离体肠平滑肌收缩有显著抑制作用,对氯化乙酰胆碱引起的肠平滑肌兴奋有显著拮抗作用（P<0.05或P<0.01）。 结论: 诃子醇提物对动物胃肠运动有抑制作用,其作用途径可能与M胆碱受体有关。     

莲心碱对离体猪冠状动脉条收缩性能的影响

 目的：观察莲心碱(Lien)拮抗氯化钾（KCl）,乙酰胆碱(Ach)和组胺(Hist)所致猪冠状动脉条收缩的作用。方法：离体平滑肌实验方法。结果：不同剂量莲心碱对KCl,Ach,Hist量效曲线均呈非竞争性拮抗作用, pD′₂值分别为4.78，3.85和4.25。莲心碱和维拉帕米（Ver）均能抑制组胺诱导的依内钙收缩，而对氯化钙诱导的依外钙收缩作用较弱。结论：莲心碱具有扩张冠脉的作用，且对冠脉平滑肌细胞依内钙性收缩及依外钙性收缩均有抑制作用。     

白藜芦醇对大鼠离体胸主动脉环的舒张作用

目的:观察白藜芦醇(resveratrol,RVL)对大鼠离体胸主动脉血管的舒张作用并探讨其机制。方法:采用离体血管环灌流方法,观察RVL在含Ca²⁺或无Ca²⁺ Krebs液孵育条件下对去甲肾上腺素(NA)引起的血管平滑肌收缩的影响;同法观察RVL对30,80mmol·L^-1的KCl引起的血管平滑肌收缩的影响;RVL对NA引起的依赖于细胞内钙和细胞外钙收缩反应的影响,以及加入N-G-硝基-L-精氨酸(L-NNA)和优降糖后RVL舒张大鼠离体主动脉环效应的变化。结果:RVL呈浓度依赖性舒张NA引起的血管收缩;无Ca²⁺ 组RVL抑制NA所致血管平滑肌收缩效应大于含Ca²⁺ 组;RVL能够拮抗NA诱发的依内钙的收缩反应,而对外钙收缩无抑制。RVL对80,30mmol·L^-1 的KCl引起的血管平滑肌收缩均有抑制作用,且前者量效曲线明显上移。L-NNA使RVL舒血管效应降低(26.0±4.6)%;优降糖组的血管舒张受抑程度与对照组无显著差别(P>0.05)。结论:RVL可呈内皮依赖性舒张血管平滑肌,其作用机制可能与该药促进NO合成释放,开放钙激活的钾通道以及抑制血管平滑肌细胞外钙内流和内钙释放有关。     

Screening of various plant extracts used in ayurvedic medicine for inhibitory effects on human immunodeficiency virus type 1 (HIV-1) protease

To identify substances with anti-human immunodeficiency virus (HIV) activity in traditional medicines, water and methanol extracts of crude drugs used in Indian traditional medicine (Ayurveda) were subjected to screening for their inhibitory effects on HIV type 1 protease (PR). The enzyme activity was determined by HPLC and of the 39 crude drugs tested, the extracts of the seeds of Areca catechu, the bark of Eugenia jambolana, the bark of Saraca indica and the stem bark of Terminalia arjuna inhibited the HIV-1 PR activity by more than 70% at a concentration of 0.2 mg/mL. The most potent inhibition was shown by the A. catechu extract, from which some procyanidins were isolated. One of them, arecatannin B1 showed significant HIV-1-PR inhibitory activity.     

Effect of the aqueous extract of Chrysanthellum indicum on calcium mobilization and activation of rat portal vein

The effects of the aqueous extract of Chrysanthellum indicum (CI) on calcium activation and mobilization were studied using the rat portal vein. The extract caused a concentration-dependent contraction of the portal vein. KCl (80 mM), norepinephrine (NA, 10(-6)M) and CI (4 mg/ml) evoked sustained contraction of the portal vein. In Ca-free medium (with EGTA) the contractions evoked by these agents were reduced significantly. The times-to-peak of KCl, NA and CI were similar -in normal PSS, but in Ca-free medium the times-to-peak for KCl and CI were greatly increased. The contractions induced by CI were not inhibited by chlorpropamide and prazosin, but were blocked by verapamil. The data obtained suggest that the aqueous extract of CI utilizes extracellular calcium pools to bring about contractile response and this effect might be mediated through the activation of potential-sensitive channels.