Pharmacological Evaluations for the Relaxant Effect of the Hydroalcoholic Extract of Tapinanthus dodoneifolius on Rat Trachea (original) (raw)
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Journal of Smooth Muscle Research, 2013
Ent-7α-hydroxytrachyloban-18-oic acid, a trachylobane diterpene from Xylopia langsdorfiana, has previously been shown to relax the guinea-pig trachea in a concentration-dependent manner. In this study we aimed to elucidate the mechanisms underlying this action and so contribute to the discovery of natural products with therapeutic potential. A possible interaction between diterpene and the Ca 2+-calmodulin complex was eliminated as chlorpromazine (10-6 M), a calmodulin inhibitor, did not significantly alter the diterpeneinduced relaxation (pD 2 = 4.38 ± 0.07 and 4.25 ± 0.07; mean ± S.E.M., n=5). Trachylobane-318 showed a higher relaxant potency when the trachea was contracted by 18 mM KCl than it did with 60 mM KCl (pD 2 = 4.90 ± 0.25 and 3.88 ± 0.01, n=5), suggesting the possible activation of K + channels. This was confirmed, as in the presence of 10 mM TEA + (a non-selective K + channel blocker), diterpene relaxation potency was significantly reduced (pD 2 = 4.38 ± 0.07 to 4.01 ± 0.06, n=5). Furthermore, K + channel subtypes K ATP , K V , SK Ca and BK Ca seem to be modulated positively by trachylobane-318 (pD 2 = 3.91 ± 0.003, 4.00 ± 0.06, 3.45 ± 0.14 and 3.80 ± 0.05, n=5) but not the K ir subtype channel (pD 2 = 4.15 ± 0.10, n=5). Cyclic nucleotides were not involved as the relaxation due to aminophylline (pD 2 = 4.27 ± 0.09, n=5) was not altered in the presence of 3 × 10-5 M trachylobane-318 (pD 2 = 4.46 ± 0.08, n=5). Thus, at a functional level, trachylobane-318 seems to relax the guinea-pig trachea by positive modulation of K + channels, particularly the K ATP , K V , SK Ca and BK Ca subtypes.
In our previous studies, pharmacological actions of Senegalese plants on the modulation of tracheal contractile responses induced by acetylcholine were demonstrated. Here, we aim to demonstrate whether the pharmacological effects previously observed, could be obtained with other contractile agonists, such as histamine and potassium chloride (KCI), in the isolated trachea after treatment with the same extracts. For this purpose, changes in contractility of isolated trachea from male Wistar rats were assessed in organ chambers. Rings were first exposed to methanolic plants extracts or solvent. After a short-term incubation period, they were contracted with acetylcholine, histamine or KCl in a cumulative manner. Salvadora persica crude extract did not alter the contractile responses of tracheal smooth muscle. Those of Hymenocardia acida persistently and significantly attenuate the contractile responses of the three agonists. Cymbopogon giganteus crude extract, in contrast, significantl...
Fundamental & Clinical Pharmacology, 2005
The relaxant effects of the Taxodium mucronatum Ten leaf hexane extract on intestinal and tracheal smooth muscle were evaluated in vitro by testing spontaneous contractions of rabbit jejunum and agonist-induced contractions of guinea pig ileum and rat trachea. The extract produced a concentration-dependent relaxation of the spontaneous contractions of rabbit jejunum (EC 50 : 4.9 ± ± ± ± 0.5 µg/ml) that was equipotent to papaverine. Following incubation of guinea pig ileum with the extract, the concentration-response curves to acetylcholine, histamine, 5-hydroxytryptamine and Ca 2+ were displaced to the right and the maximum response was significantly reduced. K + -induced contraction of the ileal tissue was completely abolished with 31.6 µg/ml of the extract. In rat tracheal rings, the extract inhibited both 1 µM carbachol (EC 50 : 33.9 ± ± ± ± 2.5 µg/ml) and 60 mM K + (EC 50 : 20.6 ± ± ± ± 1.1 µg/ml)-induced contractions. It also caused the concentration-response to Ca 2+ curves to shift to the right in a noncompetitive manner. These results demonstrate a non-specific relaxant effect that could be mediated through inhibition of calcium influx via both voltage-and receptor-gated calcium channels. The relaxant activity induced by this extract provides a rational basis for the traditional use of T. mucronatum to treat disorders of the gastrointestinal and respiratory tracts.
Pharmaceutical Biology, 2016
Context: Agastache mexicana ssp. mexicana (Kunth) Lint & Epling (Lamiaceae), popularly known as 'toronjil morado', is used in Mexican traditional medicine for the treatment of several diseases such as hypertension, anxiety and respiratory disorders. Objective: This study investigates the relaxant action mechanism of A. mexicana ssp. mexicana essential oil (AMEO) in guinea-pig isolated trachea model. Materials and method: AMEO was analyzed by GC/MS. The relaxant effect of AMEO (5-50 lg/mL) was tested in guinea-pig trachea pre-contracted with carbachol (3 Â 10 À 6 M) or histamine (3 Â 10 À 5 M) in the presence or absence of glibenclamide (10 À 5 M), propranolol (3 Â 10 À 6 M) or 2 0 ,5 0-dideoxyadenosine (10 À 5 M). The antagonist effect of AMEO (10-300 lg/mL) against contractions elicited by carbachol (10 À 15-10 À 3 M), histamine (10 À 15-10 À 3 M) or calcium (10-300 lg/mL) was evaluated. Results: Essential oil composition was estragole, D-limonene and linalyl anthranilate. AMEO relaxed the carbachol (EC 50 ¼ 18.25 ± 1.03 lg/mL) and histamine (EC 50 ¼ 13.3 ± 1.02 lg/mL)-induced contractions. The relaxant effect of AMEO was not modified by the presence of propranolol, glibenclamide or 2 0 ,5 0-dideoxyadenosine, suggesting that effect of AMEO is not related to b 2-adrenergic receptors, ATP-sensitive potassium channels or adenylate cyclase activation. AMEO was more potent to antagonize histamine (pA 2 0 ¼ À1.507 ± 0.122) than carbachol (pA 2 0 ¼ À2.180 ± 0.357). Also, AMEO antagonized the calcium chloride-induced contractions. Conclusion: The results suggest that relaxant effect of AMEO might be due to blockade of calcium influx in guinea-pig trachea smooth muscle. It is possible that estragole and D-limonene could contribute majority in the relaxant effect of AMEO.
Journal of Ethnopharmacology, 1997
The present study examined the relaxing effect of a water extract of Baibu (Stemonae radix, the root tuber of Semona sessilifolia (Miq.) Franch. et Sav.) on carbachol-, histamine-and KCl-induced contractions of the guinea-pig isolated tracheal preparations. The results showed that Baibu (1-50 mg/ml) concentration-dependently relaxed the tracheal preparations contracted by these spasmogens with an IC 50 value (mg/ml) of 2.09 0.1 for carbachol, 41.29 0.8 for histamine and 18.6 90.9 for KCl. The effect of Baibu was not affected by the pretreatment with a i-adrenoceptor antagonist propranolol (10 − 6 M), indicating that Baibu's effect was not due to an activation on i-adrenoceptors. Baibu shifted the concentration-response curve of carbachol to the right in a parallel manner without changing the maximal response, having a pA 2 value of 0.16 9 0.07 mg/ml (equivalent to a K B = 0.7090.11 mg/ml). This indicates a competitive antagonism at the muscarinic receptors. Receptor binding assay indicated that Baibu interacted with the muscarinic receptors (K i =0.5190.12 mg/ml) and the dihydropyridine (DHP) binding site of L-type Ca 2 + channels (K i =8.091.9 mg/ml), but not with the histamine H 1 receptors. Therefore, the present study demonstrates that Baibu contains the principle(s) acting on the muscarinic receptors and DHP binding sites, which contribute its relaxation effect on the airway smooth muscles.
Journal of Pharmacopuncture
Objectives: Aqueous leaf extract of Tridax procumbens (ALETP) has potent relaxant activity. However, this relaxant activity in respiratory smooth muscle remains uninvestigated. This study investigates the effect of ALETP on the contractile activity of tracheal smooth muscle (TSM) in adult male Wistar rats. Methods: Twelve male Wistar rats divided into 2 groups and were treated with either 100 mg/kg of ALETP (ALETP treatment group) or vehicle (distilled water; control group) through oral gavage for 4 weeks. Dose responses of TSM from the 2 groups to acetylcholine (10-9 to 10-5 M), phenylephrine (10-9 to 10-5 M), and potassium chloride (KCl; 10-9 to 10-4 M) were determined cumulatively. Furthermore, cumulative dose responses to acetylcholine (10-9 to 10-5 M) after pre-incubation of TSM with atropine (10-5 M), L-NAME (10-4 M), indomethacin (10-4 M), and nifedipine (10-4 M), were determined. Results: Treatment with ALETP substantially inhibited TSM contraction stimulated by cumulative doses of acetylcholine, phenylephrine, and KCl. Furthermore, preincubation of TSM from the 2 groups in atropine significantly inhibited contractility in TSM. Incubation in L-NAME and indomethacin also significantly inhibited contractility in TSM of ALETP-treated rats compared to that of controls. Contractile activity of the TSM was also inhibited significantly with incubation in nifedipine in ALETP-treated rats. Conclusion: ALETP enhanced relaxant activity in rat TSM primarily by blocking the L-type calcium channel and promoting endothelial nitric oxide release. ALETP contains agents that may be useful in disorders of the respiratory tract.
Cortex phellodendri Extract Relaxes Airway Smooth Muscle
Evidence-based complementary and alternative medicine : eCAM, 2016
Cortex phellodendri is used to reduce fever and remove dampness and toxin. Berberine is an active ingredient of C. phellodendri. Berberine from Argemone ochroleuca can relax airway smooth muscle (ASM); however, whether the nonberberine component of C. phellodendri has similar relaxant action was unclear. An n-butyl alcohol extract of C. phellodendri (NBAECP, nonberberine component) was prepared, which completely inhibits high K(+)- and acetylcholine- (ACH-) induced precontraction of airway smooth muscle in tracheal rings and lung slices from control and asthmatic mice, respectively. The contraction induced by high K(+) was also blocked by nifedipine, a selective blocker of L-type Ca(2+) channels. The ACH-induced contraction was partially inhibited by nifedipine and pyrazole 3, an inhibitor of TRPC3 and STIM/Orai channels. Taken together, our data demonstrate that NBAECP can relax ASM by inhibiting L-type Ca(2+) channels and TRPC3 and/or STIM/Orai channels, suggesting that NBAECP cou...
The Stimulatory Effects of Medicinal Plants on β2-adrenoceptors of Tracheal Smooth Muscle
Iranian Journal of Allergy, Asthma and Immunology
Medicinal plants have been identified and used as primary sources in prevention and treatment of pulmonary diseases (mainly obstructive pulmonary diseases) from ancient times due to various pharmacological activities. In this review, the stimulatory effects of extracts, some fractions and constituents of medicinal plants on β2-adrenoceptors which could be used as possible therapeutic agents in the future were reviewed. Various databases including; Medline, PubMed, ScienceDirect, Scopus, and Google Scholar were searched using stimulatory effect, β2-adrenoceptors, possible mechanism, tracheal smooth muscle (TSM), medicinal plants and their constituents as keywords from 1985 to 2017. All studied plants including; Nigella sativa, Rosa damascena, Thymus vulgaris, Carum copticom, Carum carvi, Zataria multiflora, Crocus sativus, Cuminum cyminum, Liomnia acidissima, Portulaca oleraceae, Satureja hortensis, Ephedra sinica and Achillea millefolium showed relaxant effect on tracheal smooth mus...
Journal of Ethnopharmacology, 2020
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