The pharmacological properties of the ethanolic root extract of Combretum dolichopetalum

The pharmacological actions of the crude ethanolic extract and the active fractions of the roots of Combretum dolichopetalum were tested on guinea-pig isolated ileum and in intact rats. The extract relaxed guinea-pig ileum in a concentration-dependent manner. Two active fractions (R_f 0.96 and 0.84) which also relaxed the guinea-pig ileum were isolated using column chromatography and TLC respectively. Both the crude extract and the active fractions inhibited the contractions induced by acetylcholine and histamine concentration-dependently in the guinea-pig ileum. The crude extract inhibited ulcers and gastric secretions induced in rats by pyloric ligation together with histamine 100 mg/kg, i.p. (p<0.05). The extract also delayed gastric emptying in rats in a dose-dependent manner. The effects of the extract were compared with cimetidine at each stage of the study.     

Terpenoids Isolated from Psidium guajava Hexane Extract with Depressant Activity on Central Nervous System

A bioguided fractionation of the hexane extract obtained from Psidium guajava leaves led to the isolation of sesquiterpenes with depressant activities on the central nervous system. The results demonstrated that the already reported relaxant properties of Psidium guajava hexane extract are largely due to the presence of terpenes, especially caryophyllene-oxide and β-selinene, which were by far the largest single components and potentiated pentobarbital sleeping time and the latency of convulsions induced by leptazol in mice. Calcium concentration-response curves showed a rightward displacement when the active fraction was added to isolated guinea-pig ileum depolarized with K⁺ (60 mm ) and cumulative concentrations of CaCl₂, suggesting that caryophyllene-oxide, a known Ca²⁺ antagonist agent could be responsible for the blockade of extracellular Ca²⁺ observed with the active fraction.     

Evaluation of pharmacological activity of a crude hydroalcoholic extract from Jatropha elliptica

The pharmacological effect of the hydroalcoholic extract of Jatropha elliptica was analysed in in vivo and in vitro models. When given orally in mice, the extract showed a low acute toxicity (LD₅₀ 5 g/kg). In a dose of 0.5 or 1 g/kg p.o. the extract did not interfere with diuresis in the rat, but was found to be effective in blocking rat paw oedema induced by carrageenan and partially, serotonin-induced oedema. In the same dose, the extract failed to inhibit rat paw oedema induced by dextran and the increase of rat cutaneous vascular permeability caused by Bothrops Jararaca venom, dextran, histamine, PAF-acether and serotonin. Pre-incubation of the isolated rat uterus and guinea-pig ileum with the extract (0.2–0.8 mg/mL), produced a concentration-related and non-competitive inhibition of contractions induced by acetylcholine and bradykinin. However, the extract was about 2-fold more potent in inhibiting the contraction of both agonists in guinea-pig ileum than in rat uterine muscle. In rat aorta, the extract (50–100 μg/mL) caused a concentration-dependent inhibition of noradrenaline-evoked contractions, being about 5-fold more potent when compared to the IC₅₀ values obtained in rat uterus.     

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 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.     

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.     

Effect of Aqueous Extract of Brickellia veronicaefolia on the Gastrointestinal Tract of Guinea-pig,Rats and Mice

The aqueous extract of Brickellia veronicaefolia inhibited gastric emptying time in rats and intestinal motility in mice, both effects were manifested in a dose-related fashion. The crude extract inhibited the contractions induced by acetylcholine and histamine concentration-dependently in the guinea-pig ileum. In the castor oil diarrhoea test, the extract showed 90% protection from diarrhoea at 150 mg/kg.     

Pharmacological Effects of Aqueous Extract from Valeriana adscendens

A purified aqueous extract of Valeriana adscendens Trel. (Valerianaceae) was investigated for its pharmacological profile. The extract did not exert significant changes on the nociceptive threshold in the hot plate and tail flick test and no effect was registered on the guinea-pig ileum. On the other hand, the extract significantly reduced both the locomotor activity and motor coordination of mice; it also prolonged sleep induced by pentobarbital, whereas no significant cataleptic response was observed. These effects may suggest neuroleptic-like properties.     

Analgesic Activity and Effects on Isolated Smooth Muscle of Different Fractions of Hexane Extract from Araujia sericifera Brot

The present study analyses the analgesic activity and action on in vitro motility of methanol soluble and methanol insoluble fractions obtained from the hexane extract of fruits from Araujia sericifera . The methanol fraction did not show any pharmacological activity on the different tests evaluated. However, the insoluble methanol fraction exhibited an interesting analgesic effect in models of chemical and thermal stimulus and it reduced the E _max induced by histamine in vitro on guinea-pig ileum. This extract lacked any central depressor activity since it did not modify the number of mouse movements in the activity cage.     

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 Extract of Leaf and Seed of Piper guineense on Some Smooth Muscle Activity in Rat,Guinea-pig and Rabbit

Extracts of the leaf and seed of Piper guineense were separately prepared and their pharmacological effects screened using smooth muscle of the gastrointestinal tract and uterus. The leaf extract enhanced both the frequency and tone of spontaneous contractions of rabbit jejunum and induced contraction of guinea-pig ileum, which were blocked by atropine. The seed extract had the opposite effect on rabbit jejunum, an inhibition which was antagonized by prazocin, and little or no effect on guinea-pig ileum. Both extracts had a stimulant effect on rat uterine muscle, the seed extract to a lesser extent.     

Pharmacological action of aqueous crude extracts of Artemisia verlotorum Lamotte (Compositae)

The pharmacological study of the responses evoked by a dried aqueous extract of Artemisia verlotorum on different guinea-pig and rat isolated organs in vitro, suggests a possible muscarinic activity as a cause of the antihypertensive activity. The ability of atropine, in ileum preparations, and of N_ω-nitro L -arginine methyl ester, in aortic preparations, to inhibit the plant effects seems to confirm the muscarinic nature of the responses © 1997 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。     

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.     

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.     

Pharmacological effects of phenylpropanoid glycosides from Orobanche hederae

A purified extract of Orobanche hederae, composed of two phenylpropanoid glycosides, verbascoside and orobanchoside (55:45), was investigated for its pharmacological profile. The extract did not exert significant changes on the nociceptive threshold in the hot plate test; no effect was registered on guinea-pig ileum. On the other hand, the phenylpropanoid glycoside mixture significantly prolonged sleep induced by pentobarbital and affected locomotor activity in mice; it also produced a slowing of the electroencephalographic trace and induced, when injected in the lateral cerebral ventricle, epileptiform activity in male rabbits. These effects may suggest neuroleptic-like properties.     

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.     

Pharmacological evidence for a spasmogenic agent in Datura root extract tested on dispersed smooth muscle cells of guinea-pig ileum

The effect of acetylcholine, scopolamine, and Datura leaf and root extracts on the contractility of dispersed muscle cells of guinea-pig ileum was studied. Scopolamine and crude Datura leaf extract alone or together had no significant effect on contraction of smooth muscle cells. Acetylcholine and Datura root extract either alone or together caused a significant (30%) contraction. Datura root extract reversed the effect of both scopolamine and Datura leaf extract suggesting the presence of an unknown spasmogenic factor in Datura root 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.     

Antispasmodic effect of Bersama abyssinica aqueous extract on guinea-pig ileum

The present study deals with the effect of one of the traditionally used Ethiopian medicinal plants, Bersama abyssinica, on gut motility. The experiment was carried out on isolated guinea-pig ileum with a standard spasmogen, histamine, in the absence and presence of the water extract of the medicinal plant. The spasmogenic effect of histamine was found to be antagonized by the extract in a nonreversible manner, indicating that B. abyssinica has a spasmolytic activity.