Gastrointestinal, selective airways and urinary bladder relaxant effects of Hyoscyamus niger are mediated through dual blockade of muscarinic receptors and Ca²⁺ channels

Abstract

This study describes the spasmolytic, antidiarrhoeal, antisecretory, bronchodilatory and urinary bladder relaxant properties of Hyoscyamus niger to rationalize some of its medicinal uses. The crude extract of H. niger seeds (Hn.Cr) caused a complete concentration-dependent relaxation of spontaneous contractions of rabbit jejunum, similar to that caused by verapamil, whereas atropine produced partial inhibition. Hn.Cr inhibited contractions induced by carbachol (1 microM) and K(+) (80 mM) in a pattern similar to that of dicyclomine, but different from verapamil and atropine. Hn.Cr shifted the Ca(2+) concentration-response curves to the right, similar to that caused by verapamil and dicyclomine, suggesting a Ca(2+) channel-blocking mechanism in addition to an anticholinergic effect. In the guinea-pig ileum, Hn.Cr produced a rightward parallel shift of the acetylcholine curves, followed by a non-parallel shift with suppression of the maximum response at a higher concentration, similar to that caused by dicyclomine, but different from that of verapamil and atropine. Hn.Cr exhibited antidiarrhoeal and antisecretory effects against castor oil-induced diarrhoea and intestinal fluid accumulation in mice. In guinea-pig trachea and rabbit urinary bladder tissues, Hn.Cr caused relaxation of carbachol (1 microM) and K(+) (80 mM) induced contractions at around 10 and 25 times lower concentrations than in gut, respectively, and shifted carbachol curves to the right. Only the organic fractions of the extract had a Ca(2+) antagonist effect, whereas both organic and aqueous fractions had anticholinergic effect. A constituent, beta-sitosterol exhibited Ca(2+) channel-blocking action. These results suggest that the antispasmodic effect of H. niger is mediated through a combination of anticholinergic and Ca(2+) antagonist mechanisms. The relaxant effects of Hn.Cr occur at much lower concentrations in the trachea and bladder. This study offers explanations for the medicinal use of H. niger in treating gastrointestinal and respiratory disorders and bladder hyperactivity.

Antispasmodic and bronchorelaxant activities ofSalsola imbricataare mediated through dual Ca+2antagonistic and β-adrenergic agonistic effects

“…Study on fractions revealed that Si.EtAc is more potent in relaxing K + -induced contractions, suggesting that Ca + 2 channel blocking components are concentrated in organic fraction, which is in agreement with previous studies (Gilani et al. 2008 ; Janbaz et al. 2014 ).…”

Antispasmodic and bronchorelaxant activities ofSalsola imbricataare mediated through dual Ca+2antagonistic and β-adrenergic agonistic effects

“…Study on fractions revealed that Si.EtAc is more potent in relaxing K + -induced contractions, suggesting that Ca + 2 channel blocking components are concentrated in organic fraction, which is in agreement with previous studies (Gilani et al. 2008 ; Janbaz et al. 2014 ).…”

Studies on tracheorelaxant and anti-inflammatory activities of rhizomes of Polygonatum verticillatum

“…P. verticillatum is known to possess strong anti-oxidant activity [8], which is likely to complement the anti-inflammatory potential of this plant. Similarly, β-sitosterol is known to possess the Ca 2+ channel blocking activity [22], which is again consistent with our findings, showing Ca 2+ antagonist activity of P. verticillatum .…”

Flavonols composition of Ribes nigrum L. juices and their impact on spasmolytic activity

“…In this way, Ca 2+ is reduced and the intestinal muscles relaxed. This mechanism represents the most common mode of relaxing muscle activity of plant extracts [53][54][55]. This research showed that Tenah variety exerted the strongest relaxation of the smooth muscle of ileum when the contraction was induced with KCl with no significant differences of EC 50 among years.…”

Antispasmodic and bronchorelaxant activities ofSalsola imbricataare mediated through dual Ca+2antagonistic and β-adrenergic agonistic effects

“…Study on fractions revealed that Si.EtAc is more potent in relaxing K + -induced contractions, suggesting that Ca + 2 channel blocking components are concentrated in organic fraction, which is in agreement with previous studies (Gilani et al. 2008 ; Janbaz et al. 2014 ).…”

Studies on tracheorelaxant and anti-inflammatory activities of rhizomes of Polygonatum verticillatum

“…P. verticillatum is known to possess strong anti-oxidant activity [8], which is likely to complement the anti-inflammatory potential of this plant. Similarly, β-sitosterol is known to possess the Ca 2+ channel blocking activity [22], which is again consistent with our findings, showing Ca 2+ antagonist activity of P. verticillatum .…”

Flavonols composition of Ribes nigrum L. juices and their impact on spasmolytic activity

“…In this way, Ca 2+ is reduced and the intestinal muscles relaxed. This mechanism represents the most common mode of relaxing muscle activity of plant extracts [53][54][55]. This research showed that Tenah variety exerted the strongest relaxation of the smooth muscle of ileum when the contraction was induced with KCl with no significant differences of EC 50 among years.…”

Antispasmodic and bronchorelaxant activities ofSalsola imbricataare mediated through dual Ca+2antagonistic and β-adrenergic agonistic effects

“…Study on fractions revealed that Si.EtAc is more potent in relaxing K + -induced contractions, suggesting that Ca + 2 channel blocking components are concentrated in organic fraction, which is in agreement with previous studies (Gilani et al. 2008 ; Janbaz et al. 2014 ).…”

Studies on tracheorelaxant and anti-inflammatory activities of rhizomes of Polygonatum verticillatum

“…P. verticillatum is known to possess strong anti-oxidant activity [8], which is likely to complement the anti-inflammatory potential of this plant. Similarly, β-sitosterol is known to possess the Ca 2+ channel blocking activity [22], which is again consistent with our findings, showing Ca 2+ antagonist activity of P. verticillatum .…”

Flavonols composition of Ribes nigrum L. juices and their impact on spasmolytic activity

“…In this way, Ca 2+ is reduced and the intestinal muscles relaxed. This mechanism represents the most common mode of relaxing muscle activity of plant extracts [53][54][55]. This research showed that Tenah variety exerted the strongest relaxation of the smooth muscle of ileum when the contraction was induced with KCl with no significant differences of EC 50 among years.…”