Effects on Arterial Blood Pressure of Methanol and Dichloromethanol Extracts fromJuniperus oxycedrus L.

The present study analysed the effect of the methanol and dichloromethanol extracts from Juniperus oxycedrus on arterial blood pressure in anaesthetized rats. The arterial blood pressure of normotensive rats was significantly reduced by the i.v. administration of both extracts. The hypotensive effect of these extracts was independent of the adrenergic system. These results may explain the vasorelaxing actions observed in other Juniperus species.

Nitric oxide-mediated beta 2-adrenoceptor relaxation is impaired in mesenteric veins from portal-hypertensive rats.

Abstract BACKGROUND & AIMS: beta-Adrenergic relaxation seems to be mediated by nitric oxide. The aim of this study was to evaluate changes induced by portal hypertension in beta 2-adrenergic vasorelaxation. METHODS: Isolated rat mesenteric veins were relaxed by salbutamol, and nerve- mediated vasocontractions were induced by electrical field stimulation. Responses were evaluated in the presence of NG-nitro-L-arginine methyl ester (L-NAME) or tetrodotoxin. Immunocytochemical techniques were used for localization of neuronal NO synthase. RESULTS: Salbutamol-induced relaxations were decreased in rings from portal-hypertensive animals. L- NAME reduced these relaxations, but its effects were mor…

The impact of alpha1-adrenoceptors up-regulation accompanied by the impairment of beta-adrenergic vasodilatation in hypertension

9 pages, 7 figures, 3 tables.-- PMID: 19060223 [PubMed]

The analgesic-antiinflammatory extract fromAraujia sericifera lacks ulcerogenic activity on stress-gastric damage model

The present study evaluates the ulcerogenic activity of the hexane extract from dry fruits of Araujia sericifera in an experimental model of cold-restraint stress. Treatment of rats with 200 mg/kg (i.p.) of hexane extract did not affect the gastric lesions induced by cold-restraint stress. However, it was confirmed that a dose of 300 mg/kg (i.p.) of acetylsalicylic acid (ASA) which induced a similar analgesic-antiinflammatory effect, increased significantly the level of gastric damage. Thus, the hexane extract from the fruits of A. sericifera seems to possess analgesic-antiinflammatory properties which are not linked to gastrolesive effects.

Nitric oxide and sensory afferent neurones modulate the protective effects of low-dose endotoxin on rat gastric mucosal damage

Pretreatment (1 h) with low doses (5-40 micrograms/kg i.p.) of Escherichia coli endotoxin dose dependently reduced the gastric mucosal damage induced by a 10 min challenge with 1 ml ethanol (50% and 100%) in conscious rats. Treatment with the nitric oxide synthesis inhibitor, NG-nitro-L-arginine methyl ester (L-NAME, 5 and 10 mg/kg i.p.), significantly inhibited the protective effects of endotoxin (40 micrograms/kg i.p.). The actions of L-NAME were reversed by the prior administration of L-arginine (100 mg/kg i.p.). The protective effects of endotoxin were not influenced by pretreatment with dexamethasone (5 mg/kg s.c. twice) or indomethacin (5 mg/kg s.c.). However, ablation of sensory affe…

Effects on Arterial Blood Pressure of the Methanol and Dichloromethanol Extracts from Schinus molle L. in Rats

The effects on arterial blood pressure of the methanol and dichloromethanol extracts from Schinus molle L. were analysed in urethane anaesthetized rats. In normotensive rats, the mean arterial blood pressure was significantly reduced by the i.v. administration of both extracts. The dichloromethanol extract inhibited the effects of noradrenaline on arterial blood pressure in the anaesthetized rat and it reduced the maximal contractile effect (Emax) induced by noradrenaline on rat vas deferens in the organ bath. However, the methanol extract did not modify the effects of noradrenaline in the evaluated tests.

Evaluation of the analgesic and CNS actions of different fractions from the methanol extract ofTeucrium flavum L.

Different fractions (F.1, F-3, F-5, F-6, F-7, F-8) of the methanol extract from Teucrium flavum L. have been tested for their central nervous system and analgesic activities at a dose of 200 mg/kg. Fractions F-1, F-3 and F-7 showed CNS depressant activity, while fractions F-5, F-6 and F-8 had a slight CNS stimulant action. Fractions F-5, F-6, F-7 and F-8 were responsible for the analgesic activity of the extract.

Motivo de abandono del tratamiento desde la perspectiva del paciente con un trastorno de la conducta alimentaria

Los tratamientos psicológicos y farmacológicos para los trastornos de la conducta alimentaria comportan costes personales y sanitarios. El propósito de nuestro estudio ha sido identificar los diferentes motivos que pueden estar asociados al abandono en ambos tipos de tratamientos en pacientes diagnosticados de un trastorno de la conducta alimentaria. Método: Se examinaron diversas características (edad, sexo, diagnóstico, motivos y tipos de abandono, y satisfacción respecto a la unidad de trastornos de la conducta alimentaria) en 212 pacientes atendidos en un servicio especializado en el tratamiento de trastornos de la conducta alimentaria durante un periodo de dos años. Resultados: Nuestro…

Evaluation of the analgesic action of different fractions from the methanol extract of Teucrium buxifolium L

Different fractions (F-2, F-3, F-5) of the methanol extract from Teucrium buxifolium L. have been tested for their analgesic activity in mice. All of them exhibited peripheral analgesic activity except F-3, Fraction F-5 had the strongest effect and was subjected to a second re-extraction. The subfractions obtained (F-5/3 and F-5/8) exhibited a similar activity to that observed with the whole fraction. (C) 1998 John Wiley & Sons, Ltd.

Involvement of prostaglandins and 5-hydroxytryptamine in the contractile effect of platelet-activating factor in rat isolated gastric corpus

Abstract The present study characterizes the nature of the response to the platelet-activating factor (PAF) in isolated gastric corpus with and without mucosa. PAF (10-8 M) induced contraction of rat isolated gastric corpus strips followed by desensitization of this tissue. Incubation of strips with the specific PAF-receptor antagonist WEB 2086 (5 × 10-8 − 5 × 10-5 M), the prostaglandin blocker indomethacin (10-6 M) and the 5-hydroxytryptamine antagonist methysergide (10-5 M) reduced significantly the contraction induced by PAF. Neither of the histamine H1/H2 antagonists diphenhydramine (10-6 M) or cimetidine (10-5 M) affected the contraction induced by PAF. In contrast with the whole gastr…

Pharmacological properties of the methanol extract from Mentha suaveolens Ehrh.

The present study analyses the pharmacological activity in in vivo and in vitro models of the methanol extract obtained from the leaves and steams of Menta suaveolens Ehrh. This extract lacked toxicity, but exhibited a central nervous system depressant action; an analgesic effect in models of chemical and mechanical stimulation suggesting the induction of a peripheral analgesic response. The extract also exhibited an antiinflammatory action inhibiting the rat paw oedema induced by carrageenin. Moreover, the in vitro studies showed a significant diminution in the contractile effects induced by histamine, serotonin and acetylcholine.

Protection by Almagate of Ethanol-induced Gastric Mucosal Damage in Rats

Abstract The study was designed to analyse the protective effects of almagate on a model of gastric injury, ethanol-induced mucosal damage, in which acid plays little, if any, role. Pretreatment with almagate dose-dependently reduced the level of gastric damage induced by oral administration of 1mL 100% ethanol. Administration of 12 μmol kg−1 almagate 30 min before ethanol significantly reduced the area of mucosal damage by 65 ± 10%, and the maximum level of inhibition (74 ± 11%) was obtained with 150 μmol kg−1 almagate. Administration of higher doses of almagate (200–250 μmol kg−1) did not result in any further increase in the level of protection against ethanol-induced gastric damage. Adm…

Effects on arterial blood pressure of the methanol extracts from differentTeucriumspecies

Methanol extracts of the leaves and stems of two Teucrium species (T. pumillum L. and T. buxifolium L.) have been tested for their effects on resting arterial blood pressure. Both T. pumillum L. and T. buxifolium L. extracts reduced mean arterial blood pressure in a dose dependent manner when administered i.v. to urethane anaesthetized normotensive rats. © 1997 John Wiley & Sons, Ltd.

Role of the Endothelium in the Relaxation Induced by Propofol and Thiopental in Isolated Arteries from Man

Abstract Induction of anaesthesia with intravenous propofol and thiopental is often accompanied by hypotension. This study evaluates whether propofol and thiopental induce relaxation of isolated arteries from man and whether this effect is modulated by the endothelium. Mesenteric artery rings (with and without endothelium) from 12 patients were placed in organ baths and precontracted with phenylephrine before addition of propofol (10−3 M) or thiopental (10−3 M). Relaxation induced by propofol and thiopental was evaluated for rings with intact endothelium in the presence of the nitric oxide synthase inhibitor NG-nitro-l-arginine methyl ester (l-NAME; 10−4 M) or the cyclooxygenase inhibitor i…

Importancia farmacológica y clínica de los receptores serotoninérgicos del tracto gastrointestinal

Application of viability PCR to discriminate the infectivity of hepatitis A virus in food samples.

Abstract Transmitted through the fecal–oral route, the hepatitis A virus (HAV) is acquired primarily through close personal contact and foodborne transmission. HAV detection in food is mainly carried out by quantitative RT-PCR (RT-qPCR). The discrimination of infectious and inactivated viruses remains a key obstacle when using RT-qPCR to quantify enteric viruses in food samples. Initially, viability dyes, propidium monoazide (PMA) and ethidium monoazide (EMA), were evaluated for the detection and quantification of infectious HAV in lettuce wash water. Results showed that PMA combined with 0.5% Triton X-100 (Triton) was the best pretreatment to assess HAV infectivity and completely eliminate…

Angiotensin II is involved in nitric oxide synthase and cyclo-oxygenase inhibition-induced leukocyte-endothelialcell interactionsin vivo

Chronic inhibition of nitric oxide synthase (NOS) provokes a hypertensive state which has been shown to be angiotensin II (Ang-II) dependent. In addition to raising blood pressure, NOS inhibition also causes leukocyte adhesion. The present study was designed to define the role of Ang-II in hypertension and in the leukocyte-endothelial cell interactions induced by acute NOS or cyclo-oxygenase (COX) inhibition using intravital microscopy within the rat mesenteric microcirculation. While pretreatment with an Ang-II AT1 receptor antagonist (losartan) reversed the prompt increase in mean arterial blood pressure (MABP) caused by indomethacin, it had no effect on the increase evoked by systemic L-…

Pharmacological Screening of DifferentJuniperus oxycedrusL. Extracts

Methanol and dichloromethanol extracts of leaves and stems of Juniperus oxycedrus have been tested for their toxicity, analgesic, antiinflammatory and central effects. Both extracts showed low acute toxicity and decreased spontaneous motility. The methanol extract exhibited an analgesic effect in models of chemical, mechanical and thermal stimulation whereas dichloromethanol extract showed only a significant effect in models of pain induced by chemical stimulation. Both extracts showed a significant antiinflammatory activity and inhibition of the rat paw oedema induced by carrageenin.

Gastric mucosal resistance to acute injury in experimental portal hypertension

The gastric mucosa of portal hypertensive rats exhibits important microvascular changes and a nitric oxide (NO)-dependent hyperemia. This study analyses whether portal hypertensive mucosa exhibits changes in its ability to withstand aggression. Portal hypertension was induced by partial portal vein ligation (PPVL) or common bile duct ligation (CBDL) and gastric damage was induced by oral administration of ethanol or aspirin. Experiments were performed in conscious or anaesthetized rats and some animals were pre-treated with the NO-synthesis inhibitor L-NAME. Conscious PPVL or CBDL rats showed an increased resistance to the damaging effects of ethanol. Oral administration of aspirin produced…

Anatomical differences in responsiveness to vasoconstrictors in the mesenteric veins from normal and portal hypertensive rats

The present study evaluates the effects of pre-hepatic portal hypertension, induced in rats by partial portal vein ligation, on the responsiveness of rostral (proximal) and caudal (distal) rings from the mesenteric vein. The anatomical origin of the sample influenced the response to vasoconstrictors in sham-operated animals, and this pattern of reactivity was specifically modified in portal-ligated rats. In veins from sham-operated rats, contraction induced by a submaximal concentration of KCl (60 mM) was greater in proximal than in distal rings. Vasopressin and 5-hydroxytryptamine contracted mainly distal rings, methoxamine showed a greater effect on proximal rings, and endothelin-1 and an…

In vitro pharmacological evaluation of the dichloromethanol extract fromSchinus 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.

In vitro studies of methanol and dichloromethanol extracts ofJuniperus oxycedrus L.

The present study evaluated the effect of methanol and dichloromethanol extracts obtained from the leaves and stems of Juniperus oxycedrus against neurotransmitter-induced contraction in different isolated tissues of rats and guinea-pigs. Diverse concentrations of these extracts inhibit the concentration curve response to histamine, serotonin and acetylcholine. These results contribute to explaining the use of this plant in folk medicine. © 1997 John Wiley & Sons, Ltd.

Role of central glutamate receptors, nitric oxide and soluble guanylyl cyclase in the inhibition by endotoxin of rat gastric acid secretion

1. This study examines the role of a central pathway involving glutamate receptors, nitric oxide (NO) and cyclic GMP in the acute inhibitory effects of low doses of peripheral endotoxin on pentagastrin-stimulated acid production. 2. Vagotomy or intracisternal (i.c.) microinjections of the NO-inhibitor, N(G)-nitro-L-arginine methyl esther (L-NAME; 200 microg rat(-1)) restored acid secretory responses in endotoxin (10 microg kg(-1), i.v.)-treated rats. 3. The acid-inhibitory effect of i.v. endotoxin (10 microg kg(-1), i.v.) was prevented by prior i.c. administration of the NMDA receptor antagonists, dizocilpine maleate (MK-801; 10 nmol rat(-1)) and D-2-amino-5-phosphono-valeric acid (AP-5; 20…

Globularia alypumL. extracts reduced histamine and serotonin contractionin vitro

The present study analyses in in vitro models the pharmacological activity of methanol and dichloromethane extracts (1, 10 and 100 microg/mL) obtained from the leaves and stems of Globularia alypum L. Preincubation of the guinea-pig ileum and rat uterus with both extracts produced a dose dependent abolition of the contractile effects of histamine and serotonin, respectively. At the same doses, neither methanol nor dichloromethane extract reduced the contractile effects of acetylcholine on rat duodenum or noradrenaline on rat vas deferens.