Evaluation of smooth muscle relaxant potential of Bismarckia nobilis (Hildebr. & Wendl.) in diarrhea, hypertension and asthma by ex-vivo and in-vivo method / Evaluación del potencial relajante en músculo liso de Bismarckia nobilis (Hildebr. & Wendl.) en diarrea, hipertensión y asma por métodos ex vivo e in vivo

To explore the mechanistic basis behind smooth muscle relaxant prospective of Bismarckia nobilis in gastrointestinal, respiratory and cardiovascular ailments. The methanolic extract of B. nobilis and sub-fractions have been evaluated in vitro rabbit isolated tissues, in vivo castor oil-induced diarrhea in rats and charcoal meal activity in mice. The B. nobilis extract relaxed spontaneous and K+(80 mM)- induced contractions in rabbit isolated jejunum preparations, CCh (1 µM) and K+ (80 mM)-induced contractions in tracheal and bladder preparations, PE (1 µM) and K+ (80 mM)-induced concentrations in aorta preparations, likewise verapamil. Spasmolytic activity of dichloromethane fraction is stronger as compared to aqueous fraction. In vivo castor oil-induced diarrhea in rats and charcoal meal activity in mice further supported spasmolytic activity. B. nobilis extract possess anti-spasmodic, anti-diarrheal, airway relaxant and vasodilator activities possible mediated through calcium channel blocking mechanism, justifying therapeutic utility of B. nobilis in diarrhea, asthma and hypertension.

El objetivo de trabajo fue explorar el mecanismo de acción relacionado con el efecto relajante del músculo liso inducido por Bismarckia nobilis (B. nobilis) en enfermedades gastrointestinales, respiratorias y cardiovasculares. El extracto metanólico de B. nobilis y subfracciones fue evaluado in vitro en tejidos aislados de conejos. Además se evaluó diarrea in vivo inducida con aceite de ricino en ratas y la actividad de harina de carbón vegetal en ratones. El extracto de B. nobilis relajó tanto las contracciones espontáneas como las inducidas por K+(80 mM) en preparaciones de yeyuno aisladas de conejos, las contracciones inducidas por PE (1 µM) y K+(80 mM) inducidas en preparaciones de aorta; de manera similar a verapamilo. La actividad espasmolítica de la fracción de diclorometano es más potente en comparación con la fracción acuosa. La diarrea inducida in vivo por el aceite de ricino en ratas y la actividad de la harina de carbón vegetal en ratones apoyaron aún más la actividad espasmolítica. El extracto de B. nobilis posee actividades antiespasmódicas, antidiarreicas, relajantes de las vías respiratorias y vasodilatadoras, posibles a través del mecanismo de bloqueo de los canales de calcio, lo que justifica la utilidad terapéutica de B. nobilis en la diarrea, el asma y la hipertensión.

Relaxant effects of Peperomia hispidula (Sw.) A. Dietr. on isolated rat tracheal rings / Efecto relajante de Peperomia hispidula (Sw.) A. Dietr. sobre anillos aislados de tráquea de rata

Peperomia hispidula (Sw.) A. Dietr. is used in Mexican traditional medicine for treating respiratory illnesses such as asthma. The latter disorder results from an excessive and inappropriate constriction of airway smooth muscle. The aim of the present study was to evaluate the relaxant activity of P. hispidula on isolated rat tracheal rings contracted with carbachol. The methyleugenol was identified as the main active constituent in the dichloromethane extract. To explore the possible mechanism of action, concentration-response curves were constructed in the presence and absence of propranolol (3 µM), indomethacin (10 µM), glibenclamide (1 µM), and L-NAME (300 µM), finding that neither reduced methyleugenol-induced smooth muscle relaxation. In conclusion, P. hispidula herein displayed relaxant activity on rat tracheal rings. The effect of methyleugenol, was probably not related to the activation of ß2-adrenoceptors, prostaglandins, K+ATP channels or nitric oxide.

Peperomia hispidula (Sw.) A. Dietr. es utilizada en la medicina tradicional mexicana para tratar enfermedades respiratorias como el asma. Este último trastorno es el resultado de una contracción excesiva e inapropiada del músculo liso de las vías respiratorias. El objetivo del presente estudio fue evaluar la actividad relajante de P. hispidula sobre anillos aislados de tráquea de rata contraídos con carbacol. El metileugenol fue identificado como el principal constituyente activo en el extracto de diclorometano. Para explorar el posible mecanismo de acción, se construyeron curvas concentración-respuesta en presencia y ausencia de propranolol (3 µM), indometacina (10 µM), glibenclamida (1 µM), y L-NAME (300 µM), encontrando que ninguno redujo la relajación del músculo liso inducida por metileugenol. En conclusión, P. hispidula muestra actividad relajante en anillos de tráquea de rata. El efecto de metileugenol, al parecer no está implicado con la activación de los receptores ß2-adrenérgicos, prostaglandinas, canales de K+ATP u óxido nítrico.

A study on reducing the absorption of lidocaine from the airway in cats

Abstract Purpose: To determine if the combination of lidocaine with epinephrine or gamma globulin would decrease the rate or reduce the amount of local absorption of lidocaine through the airway. Methods: Twenty adult male cats were randomly and evenly distributed into four groups: 1) Group LG: lidocaine administered with gamma globulin; 2) Group LS: lidocaine administered with physiological saline); 3) Group LE: lidocaine administered with epinephrine; 4) Group C: control group. Invasive blood pressure, heart rate, and concentration of lidocaine were recorded before and after administration. Results: The peak of plasma concentrations appeared difference (Group LG: 1.39 ± 0.23 mg/L; Group LS: 1.47 ± 0.29 mg/L and Group LE: 0.99 ± 0.08 mg/L). Compared to Group C, there were significant differences in the average heart rate of Groups LG, LS, and LE (P < 0.05). The average systolic blood pressures were significantly different when each group was compared to Group C (P < 0.05). The biological half-life, AUC0-120, peak time, and half-life of absorption among the three groups have not presented statistically significant differences (P > 0.05). Conclusion: Administering lidocaine in combination with gamma globulin through airway causes significant decrease the rate and reduce the amount of local absorption of lidocaine in cats.

Effects of emissions from sugar cane burning on the trachea and lungs of Wistar rats / Efeitos das emissões geradas pela queima da cana-de-açúcar em traqueia e pulmões de ratos Wistar

ABSTRACT Objective: To evaluate the effects of exposure to emissions from sugar cane burning on inflammatory mechanisms in tissues of the trachea and lung parenchyma in Wistar rats after different periods of exposure. Methods: This was an experimental open randomized study. The animals were divided into four groups: a control group (CG) underwent standard laboratory conditions, and three experimental groups were exposed to emissions from sugar cane burning over different periods of time, in days-1 (EG1), 7 (EG7), and 21 (EG21). After euthanasia with 200 mg/kg of ketamine/xylazine, fragments of trachea and lung were collected and fixed in 10% formalin. Histological analyses were performed with H&E and picrosirius red staining. Results: No inflammatory infiltrates were found in the tissues of CG rats. The histological examination of tissues of the trachea and lung parenchyma revealed that the inflammatory process was significantly more intense in EG7 than in the CG (p < 0.05 and p < 0.01, respectively). In comparison with the CG and EG1, angiogenesis in the lung parenchyma and collagen deposition in tracheal tissues were significantly greater only in EG21 (p < 0.001 and p < 0.01, respectively). Conclusions: In this sample, emissions from sugar cane burning induced acute focal and diffuse inflammation in the lamina propria of tracheal tissues, with no loss of ciliated epithelial tissue. In the lung parenchyma of the animals in the experimental groups, there was interstitial and alveolar edema, together with polymorphonuclear cell infiltrates.

RESUMO Objetivo: Avaliar os efeitos da exposição à fumaça da queima da cana-de-açúcar sobre mecanismos inflamatórios em tecidos de traqueia e de parênquima pulmonar de ratos Wistar após diferentes períodos de exposição. Métodos: Estudo experimental, randomizado, não cego. Os animais foram divididos em quatro grupos: controle (GC), sob condições padrão de laboratório e os demais expostos à fumaça da queima da cana-de-açúcar por diferentes períodos: em 1 (GE1), 7 (GE7) e 21 (GE21) dias. Após a eutanásia com 200 mg/kg de ketamina/xilazina, foram coletados fragmentos de traqueia e pulmão e fixadas em formol 10%. Análises histológicas foram realizadas com coloração com H&E e picrosírius. Resultados: Não houve infiltrado inflamatório nos tecidos no GC. O processo inflamatório na análise histológica de tecidos de traqueia e de parênquima pulmonar foi significativamente mais intenso no GE7 quando comparado ao GC (p < 0,05 e p < 0,01, respectivamente). Em comparação com os grupos GC e GE1, apenas no GE21 foi observada angiogênese significativa no parênquima pulmonar e aumento significativo de depósitos de colágeno em tecido de traqueia (p < 0,001 e p < 0,01, respectivamente). Conclusões: Nesta amostra, a fumaça da queima de cana-de-açúcar induziu processo inflamatório focal, difuso e agudo em tecidos de traqueia na lâmina própria, sem perda do tecido epitelial ciliado. Houve presença de edemas intersticiais e alveolares e infiltrados de células polimorfonucleares no parênquima pulmonar nos animais dos grupos experimentais.

ß-Citronellol, an alcoholic monoterpene with inhibitory properties on the contractility of rat trachea

β-Citronellol is an alcoholic monoterpene found in essential oils such Cymbopogon citratus (a plant with antihypertensive properties). β-Citronellol can act against pathogenic microorganisms that affect airways and, in virtue of the popular use of β-citronellol-enriched essential oils in aromatherapy, we assessed its pharmacologic effects on the contractility of rat trachea. Contractions of isolated tracheal rings were recorded isometrically through a force transducer connected to a data-acquisition device. β-Citronellol relaxed sustained contractions induced by acetylcholine or high extracellular potassium, but half-maximal inhibitory concentrations (IC50) for K+-elicited stimuli were smaller than those for cholinergic contractions. It also inhibited contractions induced by electrical field stimulation or sodium orthovanadate with pharmacologic potency equivalent to that seen against acetylcholine-induced contractions. When contractions were evoked by selective recruitment of Ca2+ from the extracellular medium, β-citronellol preferentially inhibited contractions that involved voltage-operated (but not receptor-operated) pathways. β-Citronellol (but not verapamil) inhibited contractions induced by restoration of external Ca2+ levels after depleting internal Ca2+ stores with the concomitant presence of thapsigargin and recurrent challenge with acetylcholine. Treatment of tracheal rings with L-NAME, indomethacin or tetraethylammonium did not change the relaxing effects of β-citronellol. Inhibition of transient receptor potential vanilloid subtype 1 (TRPV1) or transient receptor potential ankyrin 1 (TRPA1) receptors with selective antagonists caused no change in the effects of β-citronellol. In conclusion, β-citronellol exerted inhibitory effects on rat tracheal rings, with predominant effects on contractions that recruit Ca2+ inflow towards the cytosol by voltage-gated pathways, whereas it appears less active against contractions elicited by receptor-operated Ca2+ channels.

Relaxant effects of a hydroalcoholic extract of Ruta graveolens on isolated rat tracheal rings

BACKGROUND: Ruta graveolens L. (R. graveolens) is a medicinal plant employed in non-traditional medicines that has various therapeutic properties, including anthelmintic, and vasodilatory actions, among others. We evaluated the trachea-relaxant effects of hydroalcoholic extract of R. graveolens against potassium chloride (KCl)- and carbachol-induced contraction of rat tracheal rings in an isolated organ bath. RESULTS: The results showed that the airway smooth muscle contraction induced by the depolarizing agent (KCl) and cholinergic agonist (carbachol) was markedly reduced by R. graveolens in a concentration-dependent manner, with maximum values of 109 ± 7.9 % and 118 ± 2.6 %, respectively (changes in tension expressed as positive percentages of change in proportion to maximum contraction), at the concentration of 45 µg/mL (half-maximal inhibitory concentration IC50: 35.5 µg/mL and 27.8 µg/mL for KCl- and carbachol-induced contraction, respectively). Additionally, the presence of R. graveolens produced rightward parallel displacement of carbachol dose-response curves and reduced over 35 % of the maximum smooth muscle contraction. CONCLUSIONS: The hydroalcoholic extract of R. graveolens exhibited relaxant activity on rat tracheal rings. The results suggest that the trachea-relaxant effect is mediated by a non-competitive antagonistic mechanism. More detailed studies are needed to identify the target of the inhibition, and to determine more precisely the pharmacological mechanisms involved in the observed biological effects.

Expectorant and Antitussive Effect of Hedera helix and Rhizoma coptidis Extracts Mixture

PURPOSE: This study aims to investigate the additive effect of the Hedera helix (HH) and Rhizoma coptidis (RC) extracts mixture on antitussive and expectorant activities in animals. MATERIALS AND METHODS: The expectorant assay was performed with phenol red secretion in mice trachea. Mice or guinea pigs were randomly divided into groups of 8 each, including negative and positive control groups. After gastric administration of the test extracts in mice, 2.5% phenol red solution (0.2 mL) was intraperitoneally injected. Trachea was dissected and optical density of tracheal secretion was measured. After gastric administration of the test extracts in guinea pigs, the antitussive activities were assessed using a citric acid-induced cough measurement. RESULTS: The extracts of HH and RC significantly increased tracheal secretion and inhibited cough. The mixture of HH and RC extracts in a 1:1 concentration at a dose of 200 mg/kg showed a more potent effect on phenol red secretion (25.25+/-3.14) and cough inhibition (61.25+/-5.36) than the individual use of each extracts [phenol red secretion; HH 13.39+/-4.22 (p=0.000), RC 20.78+/-2.50 (p=0.010), cough inhibition; HH 9.89+/-4.14 (p=0.010), RC 30.25+/-7.69 (p=0.000)]. A 3:1 ratio mixture of HH to RC demonstrated an optimal expectorant effect (p<0.001), and this mixture showed expectorant and antitussive effects in a dose-dependent manner. CONCLUSION: This study provides evidence for antitussive and expectorant effect of a 3:1 mixture of HH and RC, which may be a useful therapeutic option for respiratory diseases.

Light-emitting diode effects on combined decellularization of tracheae. A novel approach to obtain biological scaffolds

PURPOSE: To obtain a decellularized tracheal scaffold associating traditional approaches with the novel light-emitting diode (LED) proposal. METHODS: This study was performed with New Zealand adult rabbits weighing 3.0 - 4.0 kg. Different protocols (22) were used combining physical (agitation and LED irradiation), chemical (SDS and Triton X-100 detergents), and enzymatic methods (DNase and RNase). RESULTS: Generally, the cells surrounding soft tissues were successfully removed, but none protocol removed cells from the tracheal cartilage. However, longer protocols were more effective. The cost-benefits relation of the enzymatic processes was not favorable. It was possible to find out that the cartilaginous tissue submitted to the irradiation with LED 630nm and 475 nm showed an increased number of gaps without cells, but several cells were observed to be still present. CONCLUSION: The light-emitting diode is a promising tool for decellularization of soft tissues. .

The preventive effects of natural adjuvants, G2 and G2F on tracheal responsiveness and serum IL-4 and IFN-? (th1/th2 balance) in sensitized guinea pigs

OBJECTIVE: The effects of natural adjuvants on lung inflammation and tracheal responsiveness were examined in sensitized guinea pigs. METHODS: The responses of guinea pig tracheal chains and the serum levels of interleukin-4 and interferon-gamma were examined in control pigs and three other groups of guinea pigs: the sensitized group and two other sensitized groups treated with either adjuvant G2 or adjuvant G2F (n = 7 for each group). Sensitization of the animals was achieved by injection and inhalation of ovalbumin. RESULTS: The results showed that sensitized animals had increased tracheal responsiveness and increased serum levels of interleukin-4 and interferon-gamma compared to controls (p<0.05 to p<0.001). Treatments with either G2 or G2F prevented the increase in tracheal responsiveness and serum interleukin-4 (p<0.01 to p<0.001). However, the serum levels of interferon-gamma and the interleukin-4-to-interferon-gamma ratio was increased in the treated groups (p<0.001 for all cases). CONCLUSIONS: These results indicate important preventive effects of two natural adjuvants, particularly G2, on the changes in tracheal responsiveness, serum cytokines and the interleukin-4-to-interferon-gamma ratio (T helper 1/T helper 2 balance) in sensitized guinea pigs. .

The impact of topically applied preservation solutions on the respiratory epithelium of tracheal grafts submitted to cold ischemia: functional and morphological analysis

OBJECTIVE: Advances in graft reepithelialization and revascularization have renewed interest in airway transplantation. This study aims to determine whether topically applied preservation solutions can ameliorate ischemic injury to tracheal grafts. We analyzed 1) the effects of cold ischemia on the mucociliary clearance of tracheal grafts and 2) the impact of topically applied preservation solutions on the effects of cold ischemia on mucociliary clearance. METHOD: Tracheal segments (n=217) from 109 male Wistar rats were harvested, submerged in low-potassium-dextran-glucose, histidine-tryptophan-ketoglutarate, or saline solution (saline group), and stored at 4°C for 6, 10, 16, or 24 hours. A control group (not submerged) was analyzed immediately after harvesting. In situ mucociliary transport and ciliary beating frequency were measured using a stroboscope. Epithelial integrity, cellular infiltration, and mucus storage were quantified by light microscopy and image analysis software, along with transmission electron microscopy. RESULTS: 1) The effects of cold ischemia: in situ mucociliary transport and ciliary beating frequency were greater in the control group than after cold ischemia. Microscopic analysis results were similar between groups. 2) The effects of preservation solutions: there was no difference between the low-potassium-dextran-glucose, histidine-tryptophan-ketoglutarate, and saline groups in functional or light microscopy analysis. The saline group presented stronger signs of ischemic injury with transmission electron microscopy. CONCLUSIONS: Cold ischemia diminished the mucociliary clearance of the tracheal respiratory epithelium. Topically applied preservation solutions did not ameliorate the injury caused by cold ischemia to the tracheal respiratory epithelium. .

Possible mechanism[s] of the relaxant effects of Achillea wilhelmsii on guinea-pig tracheal chains

Achillea wilhelmsii have been used in folk remedies. The relaxant effects of the extract of A. wilhelmsii on tracheal chains of guinea pigs were examined. The relaxant effects of four cumulative concentrations of the extract, theophylline and saline were examined by their relaxant effects on precontracted tracheal chains of guinea pig by KCl [group 1], 10 micro M methacholine [group 2], incubated tissues by atropine, propranolol and chlorpheniramine and contracted by KCl [group 3] and incubated tissues by propranolol and chlorpheniramine and contracted by methacholine [group 4]. In group 1 and 2, all concentrations of theophylline and three higher concentrations [4, 6 and 8 mg/mL] of the extract showed significant relaxant effects compared to that of saline. In groups 3 and 4 experiments also all concentrations of the extract showed significant relaxant effects compared to that of saline. The relaxant effect of three higher concentrations [4, 6 and 8 mg/mL] of the extract in group 1 were significantly greater than those of group 2 and in group 3 were significantly lower than those of group 1. There were significant positive correlations between the relaxant effects and concentrations for theophylline in groups 1 and 2 and the extract in all four groups of experiments. These results showed a potent relaxant effect for the extract from A. wilhelmsii on tracheal chains of guinea pigs. A muscarinc receptor blockade was also suggested for the extract

Relaxant effects of different fractions from Tymus vulgaris on guinea-pig tracheal chains

In previous studies, the relaxant effect of Tymus vulgaris has been demonstrated on guinea pig tracheal chains. Therefore, in the present study, the relaxant effects of n-hexane, dichloromethane, methanol and aqueous fractions of Tymus vulgaris on tracheal chains of guinea pigs were examined. The relaxant effects of four cumulative concentrations of each fraction (0.4, 0.8, 1.2 and 1.6 g%) in comparison to saline as negative control and four cumulative concentrations of theophylline (0.2, 0.4, 0.6 and 0.8 mM) were examined for their relaxant effects on precontracted tracheal chains of guinea pig by 60 mM KCl (group 1) and 10 ìÌ methacholine (group 2, n = 7 for each group). In group 1, all concentrations of the n-hexane fraction and theophylline and three last concentrations (0.8, 1.2 and 1.6 g%) of dichloromethane and two higher concentrations (1.2 and 1.6 g%) of methanol fractions showed significant relaxant effects compared to that of saline (p<0.05 to p<0.001). In group 2, all concentrations of theophylline, n-hexane and dichloromethane fractions and three concentrations (0.8, 1.2 and 1.6 g%) of methanol and two higher concentrations (1.2 and 1.6 g%) of aqueous fractions showed significant relaxant effects compared to that of saline (p<0.05 to p<0.001). In addition, with group 1, the relaxant effect of all concentrations of all fractions except the n-hexane fraction, were significantly less than those of theophylline (p<0.05 to p<0.001). The n-hexane fraction showed higher relaxant effect than theophylline. The relaxant effect of all concentrations of the n-hexane fraction and the three last concentrations (0.8, 1.2 and 1.6 g%) of dichloromethane and aqueous fractions were significantly greater in group 2 than in group 1 (p<0.05 to p<0.001). There were significant positive correlations between the relaxant effects and concentrations for theophylline and all fractions (except aqueous fraction in group 1) in both groups, but a negative correlation for the aqueous fraction in group 1 (p<0.05 to p<0.001). These results showed a potent relaxant effect for n-hexane and weaker relaxant effect for other fractions from Tymus vulgaris on tracheal chains of guinea pigs.

Sildenafil decreases rat tracheal hyperresponsiveness to carbachol and changes canonical transient receptor potential gene expression after antigen challenge

Inhibition of type-5 phosphodiesterase by sildenafil decreases capacitative Ca2+ entry mediated by transient receptor potential proteins (TRPs) in the pulmonary artery. These families of channels, especially the canonical TRP (TRPC) subfamily, may be involved in the development of bronchial hyperresponsiveness, a hallmark of asthma. In the present study, we evaluated i) the effects of sildenafil on tracheal rings of rats subjected to antigen challenge, ii) whether the extent of TRPC gene expression may be modified by antigen challenge, and iii) whether inhibition of type-5 phosphodiesterase (PDE5) may alter TRPC gene expression after antigen challenge. Sildenafil (0.1 µM to 0.6 mM) fully relaxed carbachol-induced contractions in isolated tracheal rings prepared from naive male Wistar rats (250-300 g) by activating the NO-cGMP-K+ channel pathway. Rats sensitized to antigen by intraperitoneal injections of ovalbumin were subjected to antigen challenge by ovalbumin inhalation, and their tracheal rings were used to study the effects of sildenafil, which more effectively inhibited contractions induced by either carbachol (10 µM) or extracellular Ca2+ restoration after thapsigargin (1 µM) treatment. Antigen challenge increased the expression of the TRPC1 and TRPC4 genes but not the expression of the TRPC5 and TRPC6 genes. Applied before the antigen challenge, sildenafil increased the gene expression, which was evaluated by RT-PCR, of TRPC1 and TRPC6, decreased TRPC5 expression, and was inert against TRPC4. Thus, we conclude that PDE5 inhibition is involved in the development of an airway hyperresponsive phenotype in rats after antigen challenge by altering TRPC gene expression.

The effect of Nigella sativa extract on tracheal responsiveness and lung inflammation in ovalbumin-sensitized guinea pigs

OBJECTIVE: To examine the preventive effect of a hydro-ethanolic extract of Nigella sativa on the tracheal responsiveness and white blood cell count in the lung lavage fluid of sensitized guinea pigs. METHODS: Three groups of guinea pigs sensitized to intraperitoneally injected and inhaled ovalbumin were given drinking water alone (group S), drinking water containing a low concentration of N. sativa extract (group S+LNS) or drinking water containing a high concentration of N. sativa extract (group S+HNS). The tracheal responses of control animals (group C) and the three groups of sensitized guinea pigs (n = 7 for all groups) to methacholine were measured by the assessment of the tracheal smooth muscle response to increasing concentrations of methacholine, and the effective concentration causing 50 percent of the maximum response (EC50) was determined. Tracheal responses to 0.1 percent ovalbumin and white blood cell counts in the lung lavage fluid were also examined. RESULTS: The tracheal response of the group S guinea pigs to both methacholine and ovalbumin was significantly higher than the response of the controls (p<0.01 for both cases). The tracheal responses of the S+LNS and S+HNS groups to both methacholine and ovalbumin were significantly decreased compared to those of the S group (p<0.05 to p<0.01). The total white blood cell and eosinophil counts in the lung lavage fluid of group S were significantly higher than those of group C (p<0.01). The white blood cell counts in both treated groups showed significant improvements (p<0.01 for both cases). CONCLUSIONS: These results demonstrate the preventive effect of the N. sativa extract on the tracheal response and lung inflammation in sensitized guinea pigs.

Effects of marmin, a compound isolated from Aegle marmelos Correa, on contraction of the guinea pig-isolated trachea

Marmin or 7-[6', 7'-dihydroxygeranyl-oxy] coumarin is a compound isolated from Aegle marmelos Correa. In the study, we examined the effects of marmin on the contraction of guinea pig-isolated trachea stimulated by several inducers, namely histamine, metacholine, compound 48/80. We also evaluated its action against contraction induced by extracellular or intracellular calcium ion. The possibility of marmin to potentiate the

elaxation effect of isoprenaline was also studied. Marmin added in the organ bath at 10 min prior to the agonist inhibited the contraction elicited by histamine and metacholine in a concentration-dependent manner. Moreover, marmin antagonized the histamine-induced contraction in competitive manner. Marmin mildly potentiated the relaxation effect of isoprenaline. In the study, marmin abrogated the contraction of tracheal smooth muscle induced by compound 48/80, an inducer of histamine release. Besides, marmin successfully inhibited CaCl[2-]-induced contraction in Ca[2+] -free Krebs solution. Marmin also inhibited two phases of contraction which were consecutively induced by metacholine and CaCl[2] in Ca[2+]-free Krebs solution. Based on the results we concluded that marmin could inhibit contraction of the guinea-pig tracheal smooth muscle, especially by interfering histamine receptor, inhibiting the histamine release from mast, inhibiting intracellular Ca[2+] release from the intracellular store and the Ca[2+] influx through voltage-dependent Ca[2+] channels

Zataria multiflora Boiss inhibits muscarinic receptors of incubated tracheal smooth muscle with propranolol

In the present study, the effect of tissue incubation with propranolol on functional antagonism of Zataria multiflora Boiss [Z. multiflora] at muscarinic receptors of tracheal smooth muscle was examined. The effects of three concentrations of aqueous-ethanolic extract, 10 nM atropine, and saline on muscarinic receptors were tested on incubated tracheal smooth muscle with propranolol [n=5]. The EC[50] of all concentration of the extract and atropine was significantly higher than that of saline. There was parallel right ward shift in concentration response curves obtained in the presence of all concentrations of the extract. There was not any significant difference in the maximum response and slope obtained in the presence of different concentrations of extract compared to saline. There was significant positive correlation between the concentrations and the values of EC[50] [p<0.001]. The value of [CR-1] obtained in the presence of highest concentration of the extract was significantly higher than that of atropine [p<0.05]. These results indicated that functional antagonism of Z. multiflora at muscarinic receptors of tracheal smooth muscle was mainly due to beta-adrenoceptor stimulatory effect of plant

Cetirizine and loratadine - comparing their antagonist effects on isolated trachea of rabbit

To study and compare the antagonist effects of Cetirizine and Loratadine on histamine induced contractions of isolated trachea of rabbit. Comparative controlled invitro experimental study. This study was conducted at The Department of Pharmacology and Therapeutics, Basic Medical Sciences Institute [BMSI] Jinnah Postgraduate Medical Center [JPMC] Karachi, for the period of six months. Isolated tracheal smooth muscles of twenty four rabbits were used. Fresh Kreb's nutritional solution was prepared for each subject. Tracheal smooth muscles were exposed to standard dilution of Histamine, and then they were challenged with serial dilutions [10 [-18]to 10 [-3]gm. /ml] of Cetirizine and Loratadine separately. Responses as rate and amplitudes of contractions were recorded by 7B Grass Polygraph machine. Cetirizine inhibit the rate of histamine induced contractions of tracheal muscles from 0.85 to 12.33% and amplitude from 0.0 to 82.69%, as concentration of drugs increased. While Loratadine inhibit the rate of histamine induced tracheal contractions from 0.85 to 10.59% and amplitude from 6.5 to 76.82% as concentration of drugs increased. Cetirizine found more potent than Loratadine as inhibitor of histamine induced contraction in isolated tracheal smooth muscles of rabbit. Basic Sciences

differences in the relaxant effects of different fractions of rosa damascena on guinea pig tracheal smooth muscle

In the present study, the differences in the relaxant effects of aqueous, ethyl acetate and n-butanol fractions of Rosa damascena on tracheal smooth muscle of guinea pigs were examined. The relaxant effects of three cumulative concentrations of each fraction [0.1, 0.2 and 0.4 g%] in comparison with saline and three cumulative concentrations of theophylline [0.1, 0.2, and 0.4 mM] were examined on precontracted tracheal chains of guinea pig by 60 mM KCl [group 1, n=5] and 10 micro M methacholine [group 2, n=8]. In group 1, all concentrations of theophylline, ethyl acetate fraction and two final concentrations of n-butanol fraction showed significant relaxant effects in comparison with saline [p< 0.05 to P< 0.001]. In group 2, all concentrations of theophylline, ethyl acetate and aqueous fractions showed concentration dependent relaxant effects compared to that of saline [p< 0.01 to P< 0.001]. In addition, the effect of ethyl acetate fraction in group 1 was significantly higher than those of theophylline [p< 0.05 to p< 0.001]. However, the effects of other fractions were significantly lower than theophylline in both groups [p< 0.01 to p< 0.001]. There were significant correlations between the relaxant effects and concentrations for theophylline and all fractions [except aqueous fractions in group 1] in both groups. The results showed a potent relaxant effect for ethyl acetate fraction of R. damascena on tracheal smooth muscle comparable to that of theophylline but a relatively weak relaxant effect for aqueous and n-butanol fractions at concentrations used

Influence of ondansetron on the antitumor activity and lung toxicity of bleomycin

Bleomycin [BLM] is well known by its antitumor activity both in vitro and in vivo. However, pulmonary fibrosis has been considered the dose limiting toxicity of the drug. Moderate nausea and vomiting occur in virtually all patients taken BLM. Ondansetron [OND] is a highly selective 5-HT3 receptor antagonist with significant antiemetic activity. This study was conducted to investigate the effect of OND administration on the antitumor and lung toxicity of BLM. The antitumor activity was evaluated both in vitro and in vivo using Ehrlich ascites carcinoma [EAC] cells. Ondansetron did not alter the antitumor effect of BLM in vitro or in vivo. The lung toxicity of BLM was evidenced by decrease in the body weight, increase in the lung/body weight ratio, decrease in the response of pulmonary arterial rings to 5-HT and increase in the contractility of tracheal smooth muscles induced by ACh. The toxicity was also confirmed biochemically by marked increases in hydroxyproline and lipid peroxidation in rat lung and the decrease in GSH level. Pretreatment with ondansetron decreased lipid peroxidation and normalized GSH level and hence enhanced the percent survival of rats. The results of the present study indicate that OND did not modify the antitumor effect of BLM but ameliorated the increase in some biochemical markers associated with BLM-induced lung toxicity

Lead acetate induced contraction in rat tracheal smooth muscle is independent of epithelium.

Airways are the primary target of lead exposure from atmospheric pollution, its effect on airway smooth muscle and their responsiveness to bronchoactive agents is not clearly understood. In the present investigation the effect of lead on the isolated airway smooth muscle activity was studied in organ bath set-up. Further the involvement of airway epithelium was examined and the responsiveness of airway smooth muscle to adenosine, acetylcholine (bronchoconstrictors) and isoproterenol (bronchodilator) was also investigated. Lead in concentration of 10(-12) M to 10(-4) M produced concentration-dependant contractile response in rat tracheal rings. Acetylcholine and adenosine induced concentration-dependent contractile response was slightly inhibited after lead exposure. The relaxant response to isoproterenol was also inhibited in lead exposed tissues. Epithelium removal did not significantly change the contractile response to lead suggesting that the lead induced contraction of airway smooth muscle is epithelium independent.