Bisnordihydrotoxiferine and vellosimine from Strychnos divaricans root: Spasmolytic properties of bisnordihydrotoxiferine

Bisnordihydrotoxiferine and vellosimine, two tertiary indole alkaloids have been isolated from the root of Strychnos divaricans. Bisnordihydrotoxiferine antagonized in a nonspecific manner, oxytocin and acetylcholine induced contractions in the rat uterus and acetylcholine and histamine responses in the guinea-pig ileum. Bisnordihydrotoxiferine, like verapamil, produced effects on voltage dependent Ca²⁺ channels. For example in guinea-pig ileum, bisnordihydrotoxiferine (pD'₂ 3.92±0.09) and verapamil (pD'₂ 6.00±0.11) inhibited KCl induced contractions. Furthermore, bisnordihydrotoxiferine (pD'₂ 4.37±0.02) and verapamil (pD'₂ 6.83±0.10) also antagonized CaCl₂ induced contractions of K⁺-depolarized rat uterus. When compared with sodium nitroprusside, an antagonist of receptor operated Ca²⁺ channels, bisnordihydrotoxiferine had no effect. However, in the aorta, the alkaloid (IC₅₀, 6.10 × 10^?6M) antagonized the intracellular calcium dependent transient contractions of noradrenaline and it was about four times more potent than procaine (IC₅₀, 2.30 × 10^?5M), a known inhibitor of the release of Ca²⁺ from intracellular stores. Bisnordihydrotoxiferine may produce nonspecific spasmolytic actions mainly by inhibiting intracellular calcium mobilization and to a lesser extent by inhibiting voltage dependent calcium channels in smooth muscles.     

The source of ca2+ for the spasmolytic actions of longicaudatine,a bisindole alkaloid isolated from Strychnos trinervis (Vell.) Mart. (Loganiaceae)

Longicaudatine, a tertiary bisindole alkaloid isolated from the root bark of Strychnos trinervis (Vell.) Mart. (Loganiaceae), antagonized in a noncompetitive manner, carbachol and histamine induced contractions of the guinea-pig ileum and bradykinin responses in the rat uterus. The respective pD₂' values (mean ± SE) were 4.61 ± 0.21, 4.98 ± 0.04 and 4.49 ± 0.01. Longicaudatine, unlike verapamil, had no effect on voltage dependent Ca²⁺ channels, as it failed to inhibit KCI or CaCl₂ induced contractions of guinea-pig ileum and depolarized rat uterus respectively. When compared with sodium nitroprusside, an antagonist of receptor operated Ca²⁺ channels, longicaudatine produced a slower and weaker inhibition of noradrenaline induced sustained contractions of rabbit aortic strips. However, in the aorta, the alkaloid antagonized the intracellular calcium dependent transient contractions of noradrenaline and longicaudatine (IC₅₀, 5.01 × 10^?7 M) was approximately 133 times more potent that procaine (IC₅₀, 6.68 × 10^?5 M), a known inhibitor of the release of Ca²⁺ from intracellular stores. Longicaudatine may exert nonspecific spasmolytic effects by acting on intracellular Ca²⁺ stores, rather than on depolarization dependent or receptor operated Ca²⁺ channels.     

Spasmolytic actions of warifteine,a bisbenzylisoquinoline alkaloid isolated from the root bark of Cissampelos sympodialis Eichl. (menispermaceae)

Warifteine, a bisbenzylisoquinoline alkaloid isolated from the root bark of Cissampelos sympodialis Eichl., produced a reversible, nonspecific and noncompetitive antagonism of histamine, carbachol and bradykinin induced contractions of the guinea-pig ileum. The corresponding pD'₂ values (mean±SE) were 4.90±0.15, 4.95±0.20 and 5.03±0.11. Warifteine also antagonized oxytocin and bradykinin induced contractions of the rat uterus in a similar manner with pD'₂ values of 4.30±0.26 and 3.76±0.06 respectively. In the guinea-pig trachea, the alkaloid inhibited spontaneous tone (IC₅₀, 1.1 × 10^?5M) as well as carbachol induced sustained contractions (IC₅₀, 2.9 × 10^?5M). As warifteine antagonized KCI induced contractions of the guinea-pig ileum (pD'₂ value 4.57±0.10), inhibition of Ca⁺⁺ influx through voltage operated Ca⁺⁺ channels may be partially responsible for its antispasmodic activity. However, the reported local anaesthetic property of warifteine may not contribute to the observed muscle relaxation as procaine failed to reduce the spontaneous tone or consistently antagonize carbachol induced contractions of the trachea and was inactive in inhibiting voltage operated Ca⁺⁺ channels in the ileum.     

Effect of Rubia cordifolia extract on acetaminophen and CCl4-induced hepatotoxicity

The hepatoprotective activity of an aqueous-methanol extract of Rubia cordifolia (Rubiaceae) was investigated against acetaminophen and CCl₄-induced hepatic damage. Acetaminophen produced 100% mortality at a dose of 1 g/kg in mice while pretreatment of animals with plant extract (500 mg/kg) reduced the death rate to 30%. Acetaminophen at a dose of 640 mg/kg produced liver damage in rats as manifested by the rise in serum levels of GOT and GPT to 1447±182 and 899±201 IU/L (n = 10) respectively, compared with respective control values of 97±10 and 36±11. Pretreatment of rats with plant extract (500 mg/kg) lowered significantly (p <0.005) the respective serum GOT and GPT levels to 161±48 and 73±29. Similarly, hepatotoxic dose of CCl₄ (1.5 mL/kg; orally) raised the serum transaminases (GOT and GPT) levels to 422±102 and 354±74 IU/L (n = 10) respectively compared with respective control values of 99±15 and 29±08 IU/L. The same dose of plant extract (500 mg/kg) was able to prevent significantly (p <0.01) the CCl₄-induced rise in serum enzymes and the estimated values of GOT and GPT were 95±09 and 33±07 IU/L, respectively. Moreover, it prevented CCl₄-induced prolongation in pentobarbital sleeping time confirming the hepatoprotective effects of the extract.     

Intestinal myorelaxant and antispasmodic effects of the essential oil of Croton nepetaefolius and its constituents cineole,methyl-eugenol and terpineol

The effects of the essential oil of Croton nepetaefolius (EOCN), a medicinal plant from the north-east of Brazil, and its constituents cineole, methyl-eugenol and terpineol, were studied on intestinal motility in vivo and on in vitro mechanical activity of intestinal smooth muscle. In mice, EOCN (10–100 mg/kg body weight, intragastrically) increased the intestinal transit of charcoal marker delivered to the stomach. This was also observed in animals pretreated with castor oil. In segments of guinea-pig ileum and cardial, pyloral and ileo-caecal sphincters, EOCN preferentially decreased basal tonus compared with the amplitude of spontaneous contractions with EC₅₀ values in the range 0.9 – 16 and 8 – 150 μg/mL respectively. In ileum, EOCN, cineole, methyl-eugenol and terpineol decreased tonus with EC₅₀ values of 16, 322, 9 and 71 μg/mL, respectively, and blocked 60 mM [K⁺]-induced contraction with IC₅₀ values of 18, 419, 12 and 95 μg/mL. The data show that EOCN possesses myorelaxant and antispasmodic properties in vitro, consistent with the use of Croton nepetaefolius in folk medicine as an intestinal antispasmodic. EOCN-induced stimulation of intestinal transit in vivo appears consistent with its in vitro effects, since a preferential decrease in tonus may reduce luminal resistance to bulk flow of intestinal contents. © 1998 John Wiley & Sons, Ltd.     

Differential antagonistic effect of hydroalcoholic extract from Hymenaea martiana hayne arzeik on kinin and other agonist-induced contractions of the isolated rat uterus and Guinea-pig ileum

This study was undertaken to evaluate the action of the hydroalcoholic extract (HE) from the bark of Hymenaea martiana on bradykinin (BK), lysyl-bradykinin (L-BK), acetylcholine (ACh), angiotensin II (AII), prostaglandin F_2a (PGF_2a), serotonin (5-HT), oxytocin (Ot) and histamine (His)-induced contractions of the isolated rat uterine muscle and guinea-pig ileum. The HE (50–200 μg/mL) added to the bath for 20 min caused a concentration-dependent rightward displacement of BK, L-BK and ACh-induced contractions in the rat uterus, allied to a discrete but significant reduction of maximal responses to the latter two agonists. By contrast, at the same range of concentrations the HE antagonized in a concentration-dependent but noncompetitive manner the contractions induced by AII, but only at high concentrations (200 μg/mL) it significantly inhibited contractions evoked by both PGF_2a and Ot, while contractile responses induced by 5-HT were not affected. In the guinea-pig ileum, the HE of H. martiana (50 and 100 μg/ml) caused a discrete rightward displacement of the BK and ACh concentration—response curves. Higher concentrations of the HE of H. martiana (200 μg/mL) caused a marked depression of BK and ACh-induced maximal responses. These findings show that the active principle(s) presents in the HE from the bark of H. martiana exhibits an interesting pharmacological profile against several neurotransmitter-induced contractions in nonvascular smooth muscles. Such actions may be relevant for supporting, at least in part, the use of this plant in folk medicine.     

Evaluation of the protective potential of Artemisia maritima extract on acetaminophen- and CCl4-induced liver damage

The hepatoprotective activity of the aqueous-methanolic extract of Artemisia maritima was investigated against acetaminophen (paracetamol, 4-hydroxy acetanilide)- and carbon tetrachloride (CCl₄)-induced hepatic damage. Acetaminophen produced 100% mortality at the dose of 1 g/kg in mice, while pretreatment of animals with the plant extract (500 mg/kg) reduced the death rate to 20%. Acetaminophen at the dose of 640 mg/kg produced liver damage in rats as manifested by the significant (P < 0.001) rise in serum levels of glutamate oxaloacetate transaminase (GOT) and glutamate pyruvate transaminase (GPT) to 1529 ± 172 I.U./l and 904 ± 116 I.U./l (n = 10), respectively, compared to respective control values of 87 ± 12 I.U./l and 31 ± 5 I.U./l. Pretreatment of rats with the plant extract (500 mg/kg) lowered significantly (P < 0.001) the respective serum GOT and GPT levels to 112 ± 10 I.U./l and 47 ± 11 I.U./l. Similarly, a hepatotoxic dose of CCl₄ (1.5 ml/kg, orally) raised significantly (P < 0.01) the serum GOT and GPT levels to 463 ± 122 I.U./l and 366 ± 58 I.U./l (n = 10), respectively, compared to respective control values of 92 ± 18 I.U./l and 35 ± 9 I.U./l. The same dose of plant extract (500 mg/kg) was able to prevent significantly (P < 0.01) the CCl₄-induced rise in serum transaminases and the estimated values of GOT and GPT were 105 ± 29 I.U./l and 53 ± 17 I.U./l, respectively. Moreover, it prevented CCl₄-induced prolongation in pentobarbital sleeping time confirming hepatoprotectivity and validates the traditional use of this plant against liver damage.     

外翻肠囊模型结合光纤传感过程分析蒜氨酸在家兔肠道的吸收

目的： 考察大蒜提取物蒜氨酸在家兔肠道内的吸收特性,为新药研究提供实验数据。 方法： 采用家兔,利用外翻肠囊模型与光纤传感过程分析系统结合,实时原位测定蒜氨酸在家兔肠道内的浓度变化。研究蒜氨酸在家兔十二指肠、空肠、回肠、结肠的4个肠段,高、中、低3个浓度的吸收,每个肠段的每个浓度进行6样本（6只家兔,共计18只家兔）分析,每个肠段接触蒜氨酸的浓度根据半数致死量确定,配制蒜氨酸溶液的质量浓度分别为（700,50,30 mg·L^-1）,于光纤传感过程分析仪上进行检测。 结果： 家兔不同肠段对蒜氨酸的吸收能力大小：回肠>空肠>结肠>十二指肠;不同浓度下各肠段的吸收数A_n值空肠分别为（2.59±0.21,5.40±0.11,3.81±0.27）;回肠分别为（5.25±0.07,3.02±0.19,4.09±0.18）,各浓度A_n值均大于1.15,十二指肠分别为（0,0.95±0.16,1.09±0.28）;结肠分别为（0.50±0.13,0.90±0.22,1.08±0.24）,各浓度A_n值均<1.15。各浓度在4个肠段的K_e值除十二指肠段外（0,0.007±0.02,0.004±0.09）其余肠段的K_e值都<0.01 cm·min^-1。 结论： 利用光纤传感系统实时测定蒜氨酸原料药在肠道的浓度变化,从而研究其在各肠段的吸收,结果表明蒜氨酸在除十二指肠段外其余肠段的渗透性很好。     

Selective modulatory effects of the essential oil of Croton zehntneri on isolated smooth muscle preparations of the guinea-pig

The effects of the essential oil of the plant Croton zehntneri (EOCz) in the concentration range 1–200 μg/mL were studied on the mechanical activity of various in vitro smooth muscle preparations of the guinea-pig. In isolated ileum EOCz induced a variable response such that in 57% of tissues basal tone was reduced (EC₅₀ 5 μg/mL) whereas the rest remained unaffected by the oil. In concentrations above 10 μg/mL EOCz induced spontaneous oscillatory contractions in all preparations. In contrast the basal tone of the aorta, portal vein and bladder remained unaltered by the oil. In the portal vein EOCz concentration-dependently inhibited the amplitude of spontaneous contractions (IC₅₀ 109 μg/mL) without reducing frequency, whereas in the bladder such activity was increased by the oil (EC₅₀ 44 μg/mL). In ileum precontracted with 60 mM KCl, EOCz induced a complete and concentration-dependent relaxation with an IC₅₀ value of approximately 26 μg/mL. In contrast EOCz did not relax KCl-induced tone in the aorta or bladder, whilst eliciting less than 20% relaxation of the precontracted portal vein. Thus our data show that EOCz exerts differential modulatory effects on the contractility of various smooth muscles of the guinea-pig. That EOCz appears to selectively relax intestinal smooth muscle may support its use in folk medicine as a gastrointestinal antispasmodic. © 1998 John Wiley & Sons, Ltd.     

淫羊藿黄酮类化合物的大鼠在体肠吸收研究

 目的研究淫羊藿中黄酮类化合物在大鼠各肠段的吸收动力学特征。方法采用大鼠在体肠灌流模型对淫羊藿苷和淫羊藿总黄酮在大鼠各肠段的吸收特性进行研究。结果淫羊藿苷在大鼠各肠段的渗透系数按空肠、十二指肠、回肠、结肠顺序依次分别为(5.25±0.17),(4.27±0.28),(1.99±0.09),(0.80±0.03);淫羊藿总黄酮中淫羊藿苷在大鼠各肠段的渗透系数按空肠、十二指肠、回肠、结肠顺序依次分别为(3.65±0.18),(4.68±0.17),(1.64±0.08),(0.58±0.26)。结论淫羊藿总黄酮中有多种成分在大鼠肠段会发生代谢转化,其中淫羊藿苷经过大鼠肠段后代谢最为明显。     

Inhibiting Activity of Some Glucoindolalkaloids and Iridoids from Sickingia williamsii on Electrically Induced Contractions of Isolated Guinea-pig Ileum

The present study examined the effects of the extracts (petroleum ether, CHCl₃, CHCl₃/MeOH (9:1) and MeOH), partially purified fractions and pure compounds (mainly alkaloids and iridoids) from Sickingia williamsii on the electrically induced contractions of the isolated guinea-pig ileum. The results of our experiments indicate that CHCl₃/MeOH (9:1) and CHCl₃ extracts, tested at concentrations of 300, 150 and 30 μg/mL, dose-dependently reduced the guinea-pig ileum electrical contractions, whereas MeOH and petroleum ether extracts did not affect it. Furthermore, both the partially purified fractions I–IV each tested at concentrations of 500, 250 and 100 μg/mL from the CHCl₃/MeOH (9:1) extract and some pure compounds (10⁻⁴ M , 5×10⁻⁵ M and 2.5×10⁻⁵ M ) isolated and purified from the above fractions significantly reduced, in a dose dependent manner, the electrical contractions of the ileum. As the active pure compounds possess an indole nucleus or/and an iridoid nucleus in their structures, the inhibitory effects appear to depend on these structures.     

家兔卡络磺钠无针注射的药动学研究

 目的 研究卡络磺钠无针注射在家兔体内的药动学规律,比较无针注射器与传统有针注射器肌内注射的注射效果。方法 以日本大耳兔为研究对象,分别通过无针注射及有针肌内注射给药,提取血清,采用高效液相色谱法进行检测,以0.12%磷酸二氢铵溶液-乙腈（91∶9）为流动相,检测波长363 nm。结果 所测得血药浓度及取血时间数据经DAS2.1.1药动学软件拟合,卡络磺钠无针注射和有针肌内注射药动学过程均符合单室模型,主要药动学参数AUC_0-t、t_max、ρmax及t_1/2分别为：（162.43±17.09）μg·min·mL^-1、（5.00±1.41）min、（5.93±0.02）μg·mL^-1、（23.54±3.89）min及（180.82±15.29）μg·min·mL^-1、（23.00±2.01）min、（5.09±0.29）μg·mL^-1、（18.28±2.47）min。结论 与传统有针注射相比,无针注射可使达峰时间显著提前、达峰浓度增加,其他药动学参数经统计学处理无显著差异,表明无针注射卡络磺钠可达到与有针注射相似的注射效果。     

Different Effects of Some Isoquinoline Alkaloids from Argemone mexicana on Electrically Induced Contractions of Isolated Guinea-pig Ileum

The present study examines the effects of the extracts [petroleum ether, CHCl₃, CHCl₃/MeOH (9:1) and MeOH], partially purified fractions and pure compounds from Argemone mexicana on the electrically induced contractions of the isolated guinea-pig ileum (E.C.I.). The results of the experiments indicate that CHCl₃/MeOH (9:1) and MeOH extracts, tested at a concentration of 400, 200 and 100 μg/mL, dose-dependently reduced the guinea-pig ileum contractions, whereas the petroleum ether and CHCl₃ extracts did not affect it. Furthermore, the partially purified fractions II–V from the MeOH extract, each tested at concentrations of 200, 100 and 50 μg/mL also inhibited E.C.I. Finally the pure compounds 1–2 (5×10⁻⁶–1×10⁻⁵–5×10⁻⁵ M ) isolated and purified from the above fractions significantly reduced, in a dose dependent manner, the electrical contractions of the ileum, whereas compound 3 (5×10⁻⁶–1×10⁻⁵×10⁻⁵ M ) increased them. Since the active compounds 1–3 were respectively identified as protopine, allocryptopine and berberine by NMR, the observed effects could be related mainly to these compounds. © 1997 by John Wiley & Sons, Ltd.     

小鼠口服3种苯并咪唑类药物的油酸、大豆油和1%西黄耆胶混悬剂的药动学

 目的 观察3种苯并咪唑类药物（阿苯达唑、芬苯达唑或氟苯达唑）的3种混悬剂（油酸、大豆油和1%西黄耆胶的混悬剂）在小鼠体内的药动学参数及其在相应介质中溶解度和生物利用度的相关性。方法 用球磨机制备阿苯达唑、芬苯达唑或氟苯达唑在油酸、大豆油和1%西黄耆胶的混悬剂（作对照剂型）。每组45～54只小鼠1次口服1种上述的苯并咪唑类药物混悬液,剂量除阿苯达唑选用100 mg·kg^-1外,其余芬苯达唑和氟苯达唑均为50 mg·kg^-1,并于给药后0.25～24 h的不同间隔时间取血,用高效液相色谱法测定血药浓度,用DAS程序计算3种苯并咪唑类药物的药动学参数。结果 小鼠口服3种苯并咪唑类药物在油酸、大豆油和1%西黄耆胶混悬剂后,阿苯达唑的平均滞留时间(MRT)分别为(3.91±0.29)、(3.70±0.09)和(1.59±0.14) h,峰浓度(ρ_max)分别为(0.66±0.08)、(0.29±0.05)和(0.34±0.09) mg·L^-1,药物浓度-时间曲线下面积(AUC)分别为(3.19±0.40)、(1.25±0.09)和(0.50±0.05) mg·L·h^-1,相对生物利用度F(油酸或大豆油混悬剂组的AUC与1%西黄耆胶混悬剂组AUC之比,下同)分别为6.38和2.50;芬苯达唑的MRT分别为(5.72±0.14)、(4.83±0.38) 和(3.85±0.25)h,ρ_max分别为(0.70±0.11)、(0.20±0.05)和(0.12±0.03) mg·L^-1, AUC分别为(5.02±0.73)、(1.08±0.21)和(0.52±0.07) mg·h·L^-1,F分别为9.65和2.08;氟苯达唑的MRT分别为(5.71±0.37)、(4.59±0.39)和(3.34±0.20)h,ρ_max分别为(0.93±0.14)、(0.58±0.09)和(0.41±0.09) mg·L^-1, AUC分别为(6.90±0.73)、(3.33±0.39)和(1.94±0.55) mg·h·L^-1;F分别为3.57和1.72。结论 小鼠一次口服阿苯达唑、芬苯达唑或氟苯达唑的2种油相混悬剂后,与1%西黄耆胶混悬剂相比,其药动学参数明显改善,延长了MRT,提高了ρ_max,同时增加了AUC和F,而且3种苯并咪唑类药物在3种介质中的溶解度与其在小鼠体内的MRT、ρ_max、AUC基本呈正相关。     

盐酸青藤碱大鼠肠吸收实验研究

 目的研究盐酸青藤碱在大鼠不同肠段的吸收特性,为其剂型设计提供理论依据。方法以酚红为标示物,采用在体单灌流法进行肠吸收实验研究,高效液相色谱法测定灌流液中盐酸青藤碱和酚红的浓度,计算吸收性能参数。结果盐酸青藤碱在十二指肠、空肠、回肠、结肠的有效渗透系数(P_eff)分别为0.65±0.15,0.54±0.26,0.45±0.14,0.28±0.12(×10^-4cm·s^-1),表明该药在大鼠各肠段均有较好的吸收。结论盐酸青藤碱适于制成日服1次的缓控释制剂。     

法罗培南钠片人体药动学研究

 目的研究中国健康受试者口服不同剂量法罗培南钠片的药动学。方法30名健康受试者(男性15名,女性15名)按性别随机分为3组,分别口服低、中、高(200,400,600mg)3个剂量的法罗培南钠片,于不同时间分别从受试者肘静脉取血4mL,离心分离血浆,对低浓度和高浓度样品分别处理后,高效液相色谱法测定血浆中法罗培南钠浓度。采用DASVer1.0药动学软件进行房室模型判断并计算药动学参数。结果法罗培南钠的体内经时过程符合有滞后时间的一室模型,口服低、中、高3个剂量组的t_max分别为(0.85±0.29),(0.73±0.34)和(0.88±0.29)h;ρ_max分别为(2.154±0.65),(4.425±2.403)和(8.126±2.635)mg·L^-1;AUC_0～t分别为(4.368±1.934),(9.273±7.817)和(18.431±9.167)mg·h·L^-1;t_1/2分别为(0.642±0.111),(0.769±0.217)和(0.702±0.120)h。结论健康人单剂量口服法罗培南钠片的体内药动学符合有滞后时间的一房室模型,ρ_max与AUC与服药剂量呈正相关。不同性别受试者单剂量口服法罗培南钠片后的药动学参数在男、女性受试者中无明显差异,表明男、女性受试者口服法罗培南钠片后的体内药动学过程基本相同。     

有机硒化合物的抗炎及抗变态反应作用

 目的：有机硒化合物具有多种活性，为此研究3种合成的有机硒化合物的抗炎作用和抗变态反应作用,并分析构效关系。方法：药物对小鼠巴豆油性耳肿胀的影响;对组胺(histamine,His)、过敏性慢反应物质(slow-reacting substance of anaphylaxis SRS-A)所致离体豚鼠回肠收缩的影响;致敏豚鼠肺中SRS-A的提取及药物的拮抗实验。结果：3种化合物能不同程度地抑制小鼠巴豆油性耳肿胀(〖WTBX〗P＜0.05或P〖WTBZ〗＜0.01)。50%抑制离体豚鼠回肠收缩时的药物浓度(IC₅₀)分别为对His:1.25×10^-5,1.58×10^-4，1.25×10^-4 mol/L,对SRS-A:8.9×10^-6，1.25×10^-4，1.12×10^-4mol/L。致敏豚鼠肺释放SRS-A的抑制浓度:10^-4mol/L。结论：3药中9108对受体的拮抗作用最强。该类化合物的化学结构中苯环(B)邻位酯基取代的化合物具有强的受体拮抗作用。它们的抗炎及抗免疫作用与其对His及SRS-A的受体拮抗作用及SRS-A的阻释作用有关。     

Effect of ambrein on smooth muscle responses to various agonists

The pharmacological effects of ambrein (isolated from ambergris) on the contractile responses induced by some agonists in smooth muscle preparations were investigated. Ambrein in the concentration range of 10, 50 and 250 μg/ml decreased the spontaneous contraction of the isolated rabbit jejunum, rat uterus and guinea-pig vas deferens. Ambrein-induced antagonism to acetylcholine (Ach) in the guinea-pig ileum was abolished when the concentration of calcium chloride in the Tyrode's solution was increased to 5 mM/l. Furthermore, ambrein did not antagonise nicotine-induced contractions in the isolated rabbit jejunum or serotonin-induced contractions in the isolated guinea-pig ileum and vas deferens or the rat uterus. However, ambrein in the concentration range of 10, 50 and 250 μg/ml antagonised prostaglandins (PGs) E₂, D₂, F_2α, and oxytocin-induced contractions in the rat uterus in vitro. Ambrein also antagonised (±) noradrenaline and (−) adrenaline-induced contractions in the isolated guinea-pig vas deferens. It is concluded that ambrein-induced non-selective dose-dependent antagonism to the effects of some agonists (Ach, adrenaline, noradrenaline, PGs and oxytocin) in some smooth muscles may be due to the ability of this compound to interfere with the mobilisation of extracellular Ca²⁺ required for muscular contractions induced by these agonists.     

Effects of the essential oil of Croton zehntneri,and its constituent estragole on intestinal smooth muscle

The effects on isolated guinea-pig ileum of the essential oil of Croton zehntneri (CZEO) and of its main constituent estragole (57% of CZEO by weight) were studied. CZEO and estragole (0.1–100 μg/mL) decreased the tonus in 56% and 61.5%, respectively, of the muscles. At concentrations above 10 μg/mL, they induced spontaneous rhythmic movements of small amplitude (less than 11% of the potassium contraction peak to peak). At concentrations from 1 to 100 μg/mL and with similar potencies, these agents blocked the contractions induced by acetylcholine, histamine and 50 mM K⁺ and caused relaxation of already established potassium contractures. Tested separately, CZEO, estragole and anethole (28% of CZEO by weight) blocked the contraction induced by Ca⁺⁺ in the presence of 50 mM K⁺, but CZEO was more potent than estragole or anethole in blocking the Ca⁺⁺-induced contractions than those induced by K⁺. With large increases in the agonist concentration, the action of the oils on the contractions induced by Ca⁺⁺ was reversible; however, their effect on contractions induced by histamine or ACh was not. The data show that the essential oil of Croton zehntneri has an effect on intestinal smooth muscle that is predominantly antispasmodic, and attributable in part to the effect of estragole, a major constituent. © 1997 John Wiley & Sons, Ltd.     

基于外翻肠囊模型的黄芪-附子配伍对附子6种生物碱肠吸收的影响研究

目的研究黄芪-附子药对配伍对附子3种单酯型生物碱(苯甲酰次乌头原碱、苯甲酰新乌头原碱、苯甲酰乌头原碱)和3种双酯型生物碱(次乌头碱、新乌头碱、乌头碱)肠吸收的影响。方法运用大鼠外翻肠囊模型,选择十二指肠、空肠、回肠为研究肠段,以表观渗透系数(P_(app))为评价指标,考察黄芪对附子6种生物碱P_(app)的影响。结果当附子-黄芪3∶1时,黄芪在十二指肠和回肠能显著降低双酯型生物碱的P_(app),在3种肠段均能降低单酯型生物碱的P_(app);当附子-黄芪1∶1时,除次乌头碱在回肠外,黄芪能显著降低双酯型生物碱的P_(app);当附子-黄芪1∶3时,黄芪能显著降低单酯型生物碱(除回肠外)的P_(app),在各肠段均能显著降低3种双酯型生物碱的P_(app)。结论黄芪可抑制附子生物碱的吸收,且其抑制作用因配伍比例、生物碱的种类和肠段不同而不同。