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.     

Effects of crinum glaucum aqueous extract on intestinal smooth muscle activity

Crinum glaucum aqueous extract (1–8 mg/mL) produced a concentration dependent, non-competitive inhibition of contractions induced by acetylcholine (1.1 × 10⁻⁸–3.3 × 10⁻⁷M ) and calcium chloride (CaCl₂, 0.05–2 mM ) on the rat duodenum. Contractions of the guinea-pig ileum induced by acetylcholine (1.1 × 10⁻⁸–3.3 × 10⁻⁷M ) and histamine (1.1 × 10⁻⁸–3.3 × 10⁻⁷M ) were inhibited by the extract (1–4 mg/mL). The extract (0.125–2.0 mg/mL) also, produced a concentration dependent relaxation of the guinea-pig taenia coli, precontracted with potassium chloride (40 mM ). It is concluded that the extract is a non-specific relaxant of the gastrointestinal smooth muscles used. © 1998 John Wiley & Sons, Ltd.     

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。     

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.     

Effects of aqueous extract of Baphia nitida on isolated cardiac tissues

The pharmacological action of cold aqueous extract of fresh leaves of Baphia nitida was studied on cardiac preparations. The extract (5.0 × 10^?3 g mL) reduced the rate and force of contraction of the isolated rabbit heart. The rate and force of contraction of the spontaneously beating rat atria was dose-dependently reduced by 5.0 × 10^?4 to 2.5 × 10^?2 g/mL of the extract and this effect was not antagonized by 3.45 × 10^?7 M atropine. The extract (5.0 × 10^?2 g mL) completely blocked the positive chronotropic and inotropic effects of 10 mM CaCI² but only reduced that of 1.61 × 10^?7 M isoprenaline. The effect of the extract on CaCI₂-induced responses of the rat atria was not affected by 3 × 10^?7 M propranolol. The use of this extract for treating palpitation locally may be related to its negative chronotropic and inotropic effects.     

Effects of Olea europaea L. extract on the rat isolated ileum and trachea

The effects of an Olea europaea L. dried leaf extract containing 3.2% of oleuropein were investigated on the rat isolated ileum and trachea. On basal tone rat isolated ileum, Olea europaea L. extract was shown to produce a dual effect characterized by a contraction at low doses (10^?7-10^?4g/mL) and a relaxation at high doses (3.10^?4-10^?3g/mL). The extract induced contractile effect was found to involve at least histamine, 5-hydroxytryptamine and thromboxane A₂. On precontracted rat isolated ileum, the extract only induced a relaxation that was not modified by nifedipine, diltiazem, dipyridamone, verapamil or papaverine (10^?6 M). The effects of the extract were also studied on the rat isolated trachea. On basal tone organs, Olea europaea L. extract did not produce any effect, whereas, when basal tone was raised by acetylcholine (ACh 10^?3 M), the drug caused a relaxation (maximal effect 39.01% ± 5.40%) of the response to theophylline; (3.10 ± 10^?3M n = 15). It is suggested that the induced relaxation is consecutive to an increase of intracellular 3′5′ cAMP.     

Effects of the flavone luteolin,isolated from Colchicum richii,on guinea-pig isolated smooth muscle and heart and on blood pressure and blood flow

The effects of the flavone luteolin, extracted from Colchicum richii, on guinea-pig isolated ileum, pulmonary artery, trachea, atrium, perfused heart, and on blood pressure and blood flow of anaesthetized guinea-pigs were studied. Luteolin (10^?5?3 × 10^?4 M) caused concentration-dependent relaxation of the tone of ileum, epinephrine-precontracted pulmonary artery and only mild relaxation of acetylcholine-precontracted trachea. These effects were not affected by pretreatment with 1 mM theophylline except in the ileum where theophylline shifted to the left the luteolin concentration-effect curve. Luteolin (3 × 10^?6?3 × 10^?4 M) caused an increase in the beating rate and the contractility of the spontaneously beating atrium and of the isolated perfused heart. Theophylline (1 mM) significantly inhibited the effects of luteolin on the atrium and the perfused heart. Luteolin, in doses of 0.3, 1.0, 1.5 and 5 mg/kg body weight had no effect on heart rate of anaesthetized guinea-pigs but caused depression of systolic and diastolic blood pressure except at the lowest dose used where there was a small increase in both parameters. Also, only the lowest dose (0.3 mg/kg) caused a small increase in blood flow. Larger doses of luteolin caused dose-related inhibition of blood flow. The effects of luteolin on blood pressure and blood flow were not affected by theophylline pretreatment (5 mg/kg). These observations suggest that the effects of luteolin may be tissue-specific and in the isolated heart they may be attributed to inhibition of cyclic AMP phosphodiesterase. The data further demonstrate that luteolin has potential cardiovascular effects that merit further investigation.     

Pharmacological activity of a procyanidin isolated from Sclerocarya birrea bark: Antidiarrhoeal activity and effects on isolated guinea-pig ileum

The antidiarrhoeal activity of a procyanidin isolated from the bark of Sclerocarya birrea was studied, using four models of experimentally induced diarrhoea in rats. The cathartic agents used were: magnesium sulphate, castor oil, arachidonic acid and prostaglandin E₂. At doses of 150 mg/kg, the procyanidin showed antidiarrhoeal activity in all the models of experimentally induced diarrhoea. The procyanidin (2.5 μg/mL-0.64 mg/mL) dose-dependently inhibited the phasic contractions of the isolated guinea-pig ileum spontaneous activity; this inhibition was significantly reduced by hexamethonium (10^?4 M ). It also modified the dose-response curves to acetylcholine in a non-competitive way, and relaxed, in a dose-dependent manner, the contractions induced by acetylcholine (10^?7 M ) and KCI (50 mM ), being five times more potent against acetylcholine. The procyanidin modified the biphasic mechanical response evoked by acetylcholine (10^?7 M ) in isolated guinea-pig ileum, inhibiting the phasic response more profoundly than the tonic one. It is concluded that the antidiarrhoeal activity of the procyanidin isolated from S. birrea bark is related to an inhibition in intestinal motility. The way in which it produces this inhibition can be related to an interference with the subsequent events evoked after muscarinic stimulation.     

Cardiovascular effects of the aqueous extract of Moringa pterygosperma

The aqueous extract of stem bark of Moriga pterygosperma (Family Moraingaceae) was investigated for its effect on various pharmacological parameters. In cardiovascular profile at lower concentrations (1–10 ng) it produced a dose dependent positive inotropic effect (n = 3, 1.29 ± 0.021 for 10 ng) and at higher concentrations (0.1–1 μg) a dose dependent negative inotropic effect (n = 3, 0.53 ± 0.033 for 1 μg) on the isolated frog heart. It also produced a dose dependent hypotensive effect on dog blood pressure (n = 3, 82 ± 0.98 for 20 mg/kg). It failed to elicit any effect on isolated guinea-pig ileum, rat stomach fundus or frog rectus abdominis muscle.     

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.     

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.     

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 interactions of paeoniflorin and veratrine on isolated rat atria

In this study, we attemped to identify the interactions and mechanisms between veratrine and paeoniflorin on isolated rat atria. Paeoniflorin alone showed no effect on the rat atria. Veratrine increased the atrial contraction and induced arrhythmia at 1×10⁻⁵ g/ml. Veratrine could directly induce contraction and elicit tetanic contraction at 1×10⁻⁴ g/ml in the left atria with or without electric stimulation. Paeoniflorin (4.8×10⁻⁶ to 4.8×10⁻³ g/ml), verapamil (2.2×10⁻⁶ g/ml), tetrodotoxin (TTX) (3.2×10⁻⁸ g/ml) and quinidine (7.5×10⁻⁶ g/ml) inhibited the increase of contraction and delayed the onset of contraction induced by veratrine (1×10⁻⁵ g/ml). The inhibitory effect of paeoniflorin combined with verapamil on the contraction induced by veratrine was more potent than that of paeoniflorin or verapamil alone. However, the inhibitory effect of paeoniflorin was not potentiated by TTX or quinidine. From the above results, the contraction evoked by veratrine in the rat atria may be concluded to be caused by the stimulation of Na⁺- and Ca²⁺-ion channels. The inhibition of paeoniflorin on the contraction induced by veratrine may primarily be related to the blockade of Ca²⁺ channels.     

Pharmacological activity of the extracts of two Satureja obovata varieties on isolated smooth muscle preparations

Aqueous extracts of two varieties of Satureja obovata Lag. subsp. obovata: var. valentina and var. obovata, exhibited a dose-dependent inhibitory effect on the contractions induced by acetylcholine (Ach) (3.4 × 10^?8?6.8 × 10^?5M) and CaCl₂ (2 × 10^?4?1.28 ? 10^?2M) in rat duodenum and by noradrenaline (NA) (10^?9?5.12 × 10^?7 M) and CaCl₂ (2 × 10^?4?1.28 × 10^?2 M) in rat aorta. The extracts also produced relaxant effects in both tissue preparations precontracted with K⁺ (75 mM) and in rat aorta precontracted with NA (10^?6 M). Vasodilatory effects of the two extracts were attenuated when the endothelium was removed. The inhibitory effects of var. valentina were stronger. These results indicated a smooth muscle relaxant effect that could account for the use of these extracts in traditional medicine.     

Herbal medicine Catuama induces endothelium-dependent and -independent vasorelaxant action on isolated vessels from rats,guinea-pigs and rabbits

The present study was designed to examine the vasorelaxant action of the herbal medicine Catuama and the hydroalcoholic extracts (HE) of each plant present in this product and to compare their effects with that caused by acetylcholine (ACh) in intact (⁺E) or in endothelium-rubbed (⁻E) rings of rat thoracic aorta (RA), guinea-pig pulmonary artery (GPPA), guinea-pig mesenteric artery (GPMA), rabbit pulmonary artery (RPA), rabbit mesenteric artery (RMA) precontracted with noradrenaline (NA) or phenylephrine (PE). The extract of Catuama (1-3000 μg/mL) produced graded relaxation of RA, ⁺E or ⁻E, with mean EC₅₀ of 430 μg/mL and ≊ 3000 μg/mL and E_max of 81 % ± 15 % and 47% ± 4 %, respectively. The nitric oxide (NO) synthase inhibitor, N^ω-nitro-L -arginine (L -NOARG, 100 μM ), inhibited in vasorelaxant action (p < 0.05) in RA (⁺E), while indomethacin (3 μM ), propranolol (1 μM ), glibenclamide (1 μM ), methylene blue (10 μM ) and apamin (0.1 μM ) had no significant effect. ACh (1-1000 μM ) caused graded relaxation in RA with ⁺E, these effects being markedly antagonized by L -NOARG (100 μM ), methylene blue (10 μM ) and partially by apamin (0.1 μM ), but not by indomethacin (3 μM ), glibenclamide (1 μM ) or propranolol (1 μM ). The Catuama extract (1-3000 μg/mL) produces partial relaxations in rings of RMA (mean EC₅₀ of 1073 μg7/ml and E_max of 56 % ± 13 %), an effect which was antagonized by L -NOARG (100 μM ). In RPA (⁺E) the extract produces partial relaxation followed by contraction (E_max 28 % ± 6 %), an effect which was abolished by L -NOARG (100 μM ) or methylene blue (10 μM ). The extract caused graded relaxation in rings of GPPA and GPMA with mean EC₅₀ values of 60 μg/mL and 1148 μg/mL and E_max 96% ± 2% and 88% ± 12%, respectively. L -NOARG (100 μM ) blocked the Catuama extract vasorelaxation in GPPA and only partially in GPMA, but markedly antagonized the vasorelaxations caused by ACh in both GPPA andRMA. The HE Paullinea cupana, Zinziber officinalis and Trichilia catigua (1-3000 μg/mL) caused a graded vasorelaxant effect ⁺E of RA with a mean EC₅₀ of 22, 55 and 1793 μg/mL and E_max 100%, 86% ± 7% 70% ± 2%, respectively. In addition the HE of P. cupana also caused graded relaxation in ⁻E of RA with EC₅₀ and E_max of 233 μg/mL and 100%, respectively, while T. catigua and Z. officinalis produced partial relaxation in RA ⁺E. In contrast the HE of Ptychopetalum olacoides caused little contraction (46% ± 14%). These results demonstrate that the medicinal herb Catuama produces significant vasorelaxation responses in vessels from different animal species, and show that its effects are in great part dependent on the release of NO or NO-derived substances. Our results also demonstrate that the vasorelaxant action of the product Catuama seems to be due to the action of the active principles present mainly in P. cupana; T. catigua and, to a lesser extent, in Z. officinalis. Such results may contribute to the explanation of its beneficial effect of Catuama herbal medicine in the management of cardiovascular disturbances. © 1997 John Wiley & Sons, Ltd.     

Effects of chalcones isolated from licorice roots on leukotriene biosynthesis in human polymorphonuclear neutrophls

The effects of chalcones and flavanones isolated from Sinkiang Licorice (Glycyrrhiza inflata Bat.) on leukotriene B₄(LTB₄) and C₄(LTC₄) formation in human polymorphonuclear neutrophils (PMNs) were investigated. Licochalcone A (2-methoxy-4,4′-dihydroxy-5-α,α-dimethyl-allylchalcone) and licochalcone B (2-methoxy-3,4,4′-trihydroxychalcone), at concentrations of 10^?3 to 10^?6 M, inhibited calcium ionophore A 23187 (A 23187)-induced LTB₄ and LTC₄ formation in human PMNs. The concentration of licochalcones A required for 50% inhibition (LC₅₀) of LTB₄ and LTC₄ formation was 4.6 × 10^?7 and 4.2×10^?6 M, respectively, using 2 μM A 23187. The IC₅₀ values of licochalcone B for LTB₄ and LTC₄ formation were also 1.2 × 10^?6 and 2.0×10^?6 M, respectively. In addition, licochalcones A and B significantly increased cyclic AMP level in human PMNs at concentrations of 10^?4 to 10^?3 M. Licochalcones A and B were found to reduce the elevation of the cytosolic free calcium concentration induced by calcium ionomycine, dose-dependently, in the presence of 1 mM Ca²⁺ or 1 mM EGTA.     

Constituents of Croton menthodorus and their effects on electrically induced contractions of the guinea-pig isolated ileum

The present study examines the effects of the extracts [petroleum ether, CHCl(3), CHCl(3)MeOH (9:1) and MeOH], partially purified fractions and pure compounds from Croton menthodorus on the electrically induced contractions of the isolated guinea-pig ileum (ECI). The results of the experiments indicate that CHCl(3)/MeOH (9:1) and MeOH extracts, tested at concentrations of 100, 50 and 25 microg/mL, dose-dependently reduced the guinea-pig ileum contractions, whereas petroleum ether and CHCl(3) extracts did not affect it. Furthermore, the partially purified fractions III-VI from the CHCl(3)/MeOH extract, each tested at concentrations of 100, 50 and 25 microg/mL also inhibited ECI. Finally, pure compound 1 (6 x 10(-6), 3 x 10(-6), 1 x 10(-6) M) isolated and purified from the most active fraction III significantly reduced, in a dose-dependent manner, the electrical contractions of the ileum. Compound 1 was identified by NMR and EI-MS data as the morphinandien-7-one, O-methylflavinantine.     

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.     

Pharmacological studies of Striga senegalensis Benth (Scrophulariaceae) as an abortifacient

The methanol extract of Striga senegalensis Benth (Scrophulariaceae) was investigated on isolated rat uterus. Acetylcholine and the methanol extract of the plant produced dose related contractions of smooth muscle of the isolated rat uterus in vitro. Atropine in doses of 2 × 10⁻² to 32 × 10⁻² μg/mL antagonized dose dependently the contraction of the isolated rat uterus produced by both acetylcholine (1.6 × 10⁻¹ μg/mL) and the methanol extract (160 μg/mL). © 1998 John Wiley & Sons, Ltd.     

Endothelium-dependent vasodilator effect of extract prepared from the seeds of Areca catechu on isolated rat aorta

Arecae semen extract relaxed aortic ring preparations of isolated rat aorta that contained endothelium from 3×10⁻⁷ g/mL, reaching a maximum of 86% at 10⁻⁵ g/mL. Its relaxation did not occur in specimens without endothelium, and was inhibited by pretreatment with 10⁻⁴ M N^G-nitro-1-arginine methylester. One of the active components was arecoline which is a muscarinic receptor agonist. Another active component was condensed tannin contained in Arecae semen. © 1997 John Wiley & Sons, Ltd.