Antidiabetic effect of Olea europaea L. in normal and diabetic rats

The antidiabetic effect of an alcohol extract of olive (Olea europaea L.) leaves was investigated in normal and streptozotocin-induced diabetic rats. The oral administration of the olive leaves extract (0.1, 0.25 and 0.5 g/kg body wt) for 14 days significantly decreased the serum glucose, total cholesterol, triglycerides, urea, uric acid, creatinine, aspartate amino transferase (AST) and alanine amino transferase (ALT) while it increased the serum insulin in diabetic rats but not in normal rats (p < 0.05). A comparison was made between the action of olive leaves extract and glibenclamide (600 microg/kg), a known antidiabetic drug. The antidiabetic effect of the extract was more effective than that observed with glibenclamide.     

Food supplementation with an olive (Olea europaea L.) leaf extract reduces blood pressure in borderline hypertensive monozygotic twins

Hypertension is a harmful disease factor that develops unnoticed over time. The treatment of hypertension is aimed at an early diagnosis followed by adequate lifestyle changes rather than pharmacological treatment. The olive leaf extract EFLA943, having antihypertensive actions in rats, was tested as a food supplement in an open study including 40 borderline hypertensive monozygotic twins. Twins of each pair were assigned to different groups receiving 500 or 1000 mg/day EFLA943 for 8 weeks, or advice on a favourable lifestyle. Body weight, heart rate, blood pressure, glucose and lipids were measured fortnightly. Blood pressure changed significantly within pairs, depending on the dose, with mean systolic differences of < or =6 mmHg (500 mg vs control) and < or =13 mmHg (1000 vs 500 mg), and diastolic differences of < or =5 mmHg. After 8 weeks, mean blood pressure remained unchanged from baseline in controls (systolic/diastolic: 133 +/- 5/77 +/- 6 vs 135 +/- 11/80 +/- 7 mmHg) and the low-dose group (136 +/- 7/77 +/- 7 vs 133 +/- 10/76 +/- 7), but had significantly decreased for the high dose group (137 +/- 10/80 +/- 10 vs 126 +/- 9/76 +/- 6). Cholesterol levels decreased for all treatments with significant dose-dependent within-pair differences for LDL-cholesterol. None of the other parameters showed significant changes or consistent trends. Concluding, the study confirmed the antihypertensive and cholesterol-lowering action of EFLA943 in humans.     

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.     

麸煨肉豆蔻不同提取物对大鼠离体肠平滑肌的影响

目的研究麸煨肉豆蔻不同提取物对大鼠离体肠管自发活动的影响。方法采用RM6240B多道生理信号采集处理系统及大鼠离体十二指肠平滑肌进行实验,观察麸煨肉豆蔻不同提取物对离体肠运动功能的影响。结果麸煨肉豆蔻挥发油、醇提物、醇提物的石油醚提取物及乙酸乙酯提取物对离体大鼠十二指肠自主运动有抑制作用,抑制率分别为51.2%、29.2%、47.8%和59.2%(P<0.01);水提物、正丁醇提取物及醇提取物萃取后的水层无抑制作用。结论麸煨肉豆蔻的挥发油、醇提物的石油醚、乙酸乙酯提取物可能为麸煨肉豆蔻止泻的有效部位。     

Inhibitory effects of the sesquiterpene T-cadinol on contractile responses in the isolated guinea-pig ileum

The smooth muscle relaxing effect of the sesquiterpene T-cadinol, isolated from scented myrrh (resin of Commiphora guidottii Chiov., Burseraceae), was investigated. The compound inhibited the contractile responses in the isolated guinea-pig ileum to histamine, carbachol, Ba²⁺ and K⁺ in a concentration dependent and reversible manner. The antagonism of the receptor-mediated contractions induced by histamine and carbachol was not of a competitive type. The contractions induced by Ba²⁺- and K⁺ were somewhat more sensitive to the action of T-cadinol than the receptor mediated contractions. It is suggested that the compound may interfere with a step of the contraction sequence common to all four spasmogens.     

Pharmacological evaluation of the dichloromethanol extract from Inula crithmoides L.

The pharmacological effect of the dichloromethanol extract of Inula crithmoides L. was analysed in in vitro and in vivo models. The extract dose-dependently decreased arterial blood pressure and furthermore it showed low acute toxicity, CNS depressor activity and analgesic and antiinflammatory effects. Preincubation of the guineapig ileum and rat duodenum (100 μg/mL) produced a significant reduction in the contractile effects of histamine and acetylcholine and a concentration-related inhibition of the effects of serotonin. Following further fractionation the methylene chloride/acetone (50/50) fraction caused a significant decrease in motor activity and significantly reduced the threshold of pain chemical stimulus.     

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.     

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.     

In vitro pharmacological evaluation of the dichloromethanol extract from Schinus molle l.

The pharmacological activity of the dichloromethanol extract of Schinus molle L. (SM-DCM) was analysed in in vitro models. Preincubation of the isolated guinea-pig ileum or rat uterus preparations with the extract (100 μg/mL) abolished the contractile effects of histamine and serotonin respectively. At the same dose, the extract partially reduced the contractile effects of acetylcholine on the isolated rat duodenum. A 10 μg/mL dose showed an inhibitory effect on histamine and serotonin, but not on acetylcholine-induced contractions (NS). No significant effect was found with a 1 μg/mL dose. © 1998 John Wiley & Sons, Ltd.     

Mechanism of action of the aqueous seed extract of Mucuna pruriens on the guinea-pig ileum

The hot water extract (HWE) of the seed of Mucuna pruriens dose-dependently contracted the guinea-pig ileum. The ED₅₀ and pD₂ values for the HWE was lower than those of ACh and histamine. Cyproheptadine and promethazine (10 ng/mL) significantly antagonized the effects of histamine, 5-hydroxytryptamine (5-HT) and HWE. Atropine blocked the effect of ACh and partially blocked the HWE. The calcium channel blockers nifedipine and verapamil both blocked the effects of all the agonists including HWE. These results suggest that the HWE contains potent histamine receptor stimulants or principles as it was blocked by low doses of H₁ receptor blockers. It appears that stimulation of the receptors leads to influx of calcium since the effect was also blocked by nifedipine and verapamil. It is likely that it also stimulates muscarinic receptors. © 1997 John Wiley & Sons, Ltd.     

Relaxant effect of essential oil and hydro-alcoholic extract of Pycnocycla spinosa Decne. exBoiss. on ileum contractions

Pycnocycla spinosa is an essential oil from a wild plant growing in central Iran. However, so far its pharmacological effects have not been studied. The aim of this study was to look for relaxant effects of the essential oil and hydro-alcoholic extract of P. spinosa on rat isolated ileum contractions induced by KCl and acetylcholine (ACh). P. spinosa essential oil (PSEO) and the hydro-alcoholic extract inhibited the response to 80 mM KCl in a concentration-dependent manner and attenuated the maximum attainable response of ACh concentration-response curve. Furthermore, in caster oil induced diarrhoea, the hydro-alcoholic extract had a dose-dependent anti-diarrhoeal effect. This study showed that P. spinosa essential oil and its hydro-alcoholic extract act as a relaxant of rat isolated ileum. As the inhibition of contractile over-activity of the ileum is the basis for the treatment of gastro-intestinal disorders such as diarrhoea, P. spinosa may have clinical bene fi ts for treatment of this condition.     

Effects of Daniellia oliveri bark on isolated rat bladder.

The stem bark of Daniellia oliveri was screened phytochemically and a methanol extract prepared.-Condensed tannins, saponins, cyanogenetic and cardiac glycosides were identified in the crude drug. The cardiac glycoside components in the methanol extract were precipitated with acetone to yield a reddish-brown residue. The n-butanol soluble fraction of an aqueous solution of this residue tested positive for cardiac glycosides and was shown by TLC to contain steroidal compounds. This fraction was subjected to pharmacological studies on isolated rat bladder smooth muscle. It had no effect on purinergic neurotransmission but was a noncompetitive antagonist for muscarinic receptors.     

东北鹤虱中香豆素类对兔离体回肠的作用

目的：观察东北鹤虱中香豆素类对兔离体回肠的作用及对钙离子的影响。方法：采用兔离体回肠标本，结予不同剂量香豆素（CM）及维拉帕米（Ver)，观察对平滑肌收缩的影响。结果：CM和Ver可剂量依赖性地抑制乙酰胆碱（Ach）引起的回肠的收缩，非竞争性拮抗Cacl2所致回肠收缩，并对Ach引起的第1，2相收缩有影响。结论：东北鹤虱中提取的香豆素类具有与Ver相似的钙拮抗作用。     

Essential oil of Pterodon polygalaeflorus inhibits electromechanical coupling on rat isolated trachea

The present work studied the effects of the essential oil of Pterodon polygalaeflorus (EOPP), a plant used to treat bronchitis and amigdalytis, on rat airway smooth muscle in vitro. In Ca(2+)-containing medium, EOPP (100-1300 microg/ml) inhibited preferentially high KCl- than 5-HT-induced muscle contractions in a concentration-dependent fashion, but did affect neither basal muscle tension nor ACh-induced contractions. In preparations maintained in either 60 mM K(+) or 10 microM ACh in Ca(2+)-free medium, EOPP (100, 600 and 1300 microg/ml) inhibited maximum contractile response induced by cumulative Ca(2+) addition (0.1-20 mM). Verapamil (10, 30 and 100 microg/ml), a Ca(2+) channel blocker, also inhibited Ca(2+)-induced concentration-effect curve in presence of ACh in Ca(2+)-free medium, whilst it was ineffective to decrease cholinergic contractions in Ca(2+)-containing medium. In presence of 150 mM K(+) in Ca(2+)-containing medium, EOPP (1300 microg/ml) did not reversed ACh-induced contractions. In contrast, under similar conditions, EOPP almost fully relaxed cholinergic contractions of tracheal smooth muscle in Ba(2+)-containing medium. In medium containing 10 mM tetraethylammonium and 2 mM Ba(2+) instead of Ca(2+), both EOPP (1300 microg/ml) and verapamil (approximately 5 microg/ml) significantly decreased ACh-induced contractions. Thus, in rat isolated trachea, EOPP induces inhibitor effects on contractions preferentially triggered by an electromechanical coupling mode.     

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.     

青心酮对豚鼠离体气管条张力的影响及其机制

采用气管条浴槽实验方法,观察青心酮对离体豚鼠气管螺旋条张力的影响。结果发现：ＤＨＡＰ明显松驰豚鼠的离体气管平滑肌;抑制由乙酰胆碱、组胺和氯化钾所了体豚鼠气管平滑肌的收缩反应,对５－羟色胺诱发的由内钙释放引起的Ⅰ相收缩和外钙内流所致的Ⅱ相气管平滑肌收缩均有一定的抑制作用。     

Effect of Backebergia militaris cactus extract on intestinal smooth muscle contractility

The branches of the giant cactus Backebergia militaris contain at least one biologically active compound, corresponding to an alkaloid. This activity was not dependent on cactus age. Methanol crude extracts of B. militaris showed a clear inhibitory effect on rabbit intestinal smooth muscle contractility. The inhibitory activity was concentration-dependent, and reversible upon removal of the extract from the medium. B. militaris extract did not display any anticholinergic action on the rabbit intestine. Copyright © 1998 John Wiley & Sons, Ltd.     

射干提取物止咳祛痰药理实验研究

[目的]研究射干提取物对浓氨水引起小鼠咳嗽次数及咳嗽潜伏期的影响、对小鼠腹腔注射酚红后引起气管酚红排泌量的影响。[方法]将小鼠放入加有浓氨水的诱咳引喘仪内,雾化5sec,观察记录小鼠的咳嗽潜伏期和2min内咳嗽次数,小鼠腹腔注射5%酚红溶液,测定30min后小鼠气管酚红的排泌量。[结果]射干提取物0.46g(提取物)/kg、0.92g(提取物)/kg、1.84g(提取物)/kg剂量能明显延长氨水引起的小鼠咳嗽潜伏期、降低2min内小鼠咳嗽次数,明显增加小鼠气管酚红排泌量,与空白对照组比较有显著性差异(P<0.05,P<0.01,P<0.001)。[结论]射干提取物具有止咳祛痰作用。     

Effects of Thymus species extracts on rat duodenum isolated smooth muscle contraction

The diethylether, ethylacetate and butanolic extracts from Thymus webbianus and Thymus leptophyllus were tested for spasmolytic activity. Pre-incubation of the isolated rat duodenum with these extracts for 10 min produced a concentration-dependent inhibition of acetylcholine-induced contractions. This effect was at least ten times greater with the apolar extracts than with the polar extracts.     

Olea europaea L. and oleuropein: Effects on excito-conduction and on monophasic action potential in anaesthetized dogs

The effects of a glyceroethanolic macerate of the leaves of Olea europaea L. and of oleuropein on excito-conduction and on the right atrial and ventricular monophasic action potential (MAP) have been studied in anaesthetized dogs using the technique of endocavitary recording. At the higher doses tested, a slight increase in the sinusal cycle of the sinoatrial conduction time and of the sinus node recovery time, together with a prolongation of the atrioventricular and intraventricular conduction and an increase of the atrial and ventricular MAP duration were observed. This may be due to a decrease in the repolarization phase 3. These electrophysiological effects indicate an inhibitory action both on the swift influx of sodium and on the slow influx of calcium, as well as a decrease in potassium conductance.