Evaluation of gut modulatory and bronchodilator activities of <it>Amaranthus spinosus</it> Linn.
<p>Abstract</p> <p>Background</p> <p>The aqueous-methanolic extract of <it>Amaranthus spinosus</it> (<it>A. spinosus</it> Linn.,) whole plant, was studied for its laxative, spasmolytic and bronchodilator activities to validate some of its medicin...
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| Main Authors: | , , , , , |
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| Format: | Book |
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BMC,
2012-10-01T00:00:00Z.
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| Summary: | <p>Abstract</p> <p>Background</p> <p>The aqueous-methanolic extract of <it>Amaranthus spinosus</it> (<it>A. spinosus</it> Linn.,) whole plant, was studied for its laxative, spasmolytic and bronchodilator activities to validate some of its medicinal uses.</p> <p>Methods</p> <p>The crude extract of <it>A. spinosus</it> was studied <it>in-vivo</it> for bronchodilator and laxative activities and <it>in-vitro</it> using isolated tissue preparations which were mounted in tissue baths assembly containing physiological salt solutions, maintained at 37°C and aerated with carbogen, to assess the spasmolytic effect and to find out the possible underlying mechanisms.</p> <p>Results</p> <p>In the <it>in-vivo</it> experiments in mice, the administration of <it>A. spinosus</it> increased fecal output at doses of 100 and 300 mg/kg showing laxative activity. It also inhibited carbachol-induced bronchospasm in anesthetized rats at 1, 3, 10 and 30 mg/kg indicative of bronchodilator activity. When tested on isolated gut preparations, the plant extract showed a concentration-dependent (0.01-10.0 mg/ml) spasmogenic effect in spontaneously contracting rabbit jejunum and guinea-pig ileum. The spasmogenic effect was partially blocked in tissues pretreated with atropine (0.1 μM). When tested on K<sup>+</sup> (80 mM)-induced sustained contractions in isolated rabbit jejunum, the plant extract caused complete relaxation and also produced a shift in the Ca<sup>++</sup> concentration-response curves (CRCs) towards right, similar to diltiazem. In rabbit trachea, the plant extract completely inhibited K<sup>+</sup> (80 mM) and carbachol (CCh, 1 μM)-induced contractions at 1 mg/ml but pretreatment of tissue with propranolol (1 μM), caused around 10 fold shift in the inhibitory CRCs of the plant extract constructed against CCh-induced contraction. The plant extract (up to 0.3 mg/ml) also increased both force and rate of spontaneous contractions of isolated guinea-pig atria, followed by relaxation at higher concentration (1.0-5.0 mg/ml). The cardio-stimulant effect was abolished in the presence of propranolol, similar to that of isoprenaline. Activity-directed fractionation revealed that the spasmolytic component(s) was separated in the organic fraction, whereas the spasmogenic component was concentrated in the aqueous fraction.</p> <p>Conclusion</p> <p>These results indicate that <it>A. spinosus</it> possesses laxative activity partially mediated through cholinergic action. The spasmolytic effect was mediated through calcium channel blocking (CCB), while bronchodilator activity through a combination of β-adrenergic and CCB pathways, which may explain the traditional uses of <it>A. spinosus</it> in gut and airways disorders.</p> |
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| Item Description: | 10.1186/1472-6882-12-166 1472-6882 |