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.

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.

Relaxant effects of different fractions from Nigella sativa L. on guinea pig tracheal chains and its possible mechanism(s).

The relaxant effects of four cumulative concentrations of n-hexane, dichloromethane, methanol and aqueous fractions of N. sativa (0.8, 1.2, 1.6 and 2.0 g%) in comparison with saline as negative control and four cumulative concentrations of theophylline (0.2, 0.4, 0.6 and 0.8 mM) were examined by their relaxant effects on precontracted tracheal chains of guinea pig by 60 mM KCl (group 1) and 10 microM methacholine (group 2). In group 1, all concentrations of only theophylline showed significant relaxant effects. However, in group 2, all concentrations of theophylline and methanol fraction, 1.2, 1.6 and 2.0 g% concentrations of dichloromethane and 1.2 and 2.0 g% concentrations of n-hexane fractions showed significant relaxant effects compared to that of saline. In addition, in group 1, the relaxant effect of most concentrations of all fractions except the low concentration (0.8 g%) of dichloromethane and methanol fraction were significantly less than those of theophylline. The relaxant effect of different concentrations of methanol and dichloromethane fraction and 1.2, 1.6 and 2.0 g% concentrations of n-hexane fraction were significantly greater in group 2 compared to group 1 experiments. There were significant positive correlations between the relaxant effects and concentrations for all fractions (except aqucous fraction) in group 2 and for theophylline in both groups but a negative correlation for n-hexane, dichloromethane and methanol fractions in group 1. The results showed relaxant effect of most fractions from N. sativa on tracheal chains of guinea pigs which was more potent for methanol and dichloromethane fractions.