Planta Med 2010; 76(3): 218-222
DOI: 10.1055/s-0029-1186054
Pharmacology
Original Papers
© Georg Thieme Verlag KG Stuttgart · New York

The Effect of Thymoquinone, the Main Constituent of Nigella sativa on Tracheal Responsiveness and White Blood Cell Count in Lung Lavage of Sensitized Guinea Pigs

Rana Keyhanmanesh1 , 2 , 3 , Mohammad Hossein Boskabady4 , Mohammad Javad Eslamizadeh4 , Saeed Khamneh3 , Mohammad Ali Ebrahimi5
  • 1Department of Physiology, Tabriz University of Medical Sciences, Tabriz, Iran
  • 2Drug Applied Research Centre, Tabriz University of Medical Sciences, Tabriz, Iran
  • 3Tuberclosis and Lung Research Centre, Tabriz University of Medical Sciences, Tabriz, Iran
  • 4Department of Physiology and Pharmacological Research Centre of Medical Plants, Medical School, Mashhad University of Medical Sciences, Mashhad, Iran
  • 5Department of Basic Sciences, Islamic Azad University, Tabriz Branch, Tabriz, Iran
Further Information

Publication History

received April 25, 2009 revised July 19, 2009

accepted July 22, 2009

Publication Date:
26 August 2009 (online)

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Abstract

In previous studies, the relaxant, anticholinergic (functional antagonism) and antihistaminic, effects of Nigella sativa have been demonstrated on guinea pig tracheal chains. In the present study, the prophylactic effect of thymoquinone (one of the constituents of Nigella sativa) on tracheal responsiveness and white blood cell (WBC) count in lung lavage of sensitized guinea pigs was examined. Four groups of sensitized guinea pigs to ovalbumin (OA) were given drinking water alone (group S), drinking water containing low or high concentrations of thymoquinone (S + LTQ and S + HTQ groups) or inhaled fluticasone propionate (FP 250 µg) twice a day (positive control group) (n = 7, for all groups). Tracheal responses of control and four groups of sensitized animals to methacholine at an effective concentration causing 50 % of maximum response (EC50 M) were measured. Tracheal responses to 0.1 % OA, relative to contraction induced by 10 µM methacholine were also examined. Total WBC and its differential count in lung lavage were also measured. The tracheal responsiveness to methacholine, OA and WBC of S guinea pigs was significantly higher than those of controls (p < 0.001 for all cases). Tracheal responsiveness in S + LTQ, S + HTQ, and FP groups to both methacholine (p < 0.05 to p < 0.001) and OA (p < 0.001 for all cases) was significantly decreased compared to that of the S group. Total WBC was also decreased in all experimental groups compared to that of the S group (p < 0.001 for all groups). There was an increase in eosinophils and a decrease in neutrophils, lymphocytes and monocytes in the S animals compared to the controls (p < 0.001 for all cases). Treatment with both concentrations of thymoquinone and FP variably improved differential WBC count changes compared to the S animals (nonsignificant to p < 0.001). The improvement in tracheal responsiveness, total WBC, eosinophils and lymphocytes changes in the S animals treated with both concentrations of TQ were significantly greater than those of FP (p < 0.05 to p < 0.001). These results showed a preventive effect of thymoquinone, one constituent of N. sativa, on tracheal responsiveness and inflammatory cells of lung lavage of sensitized guinea pigs which was comparable or even greater than that of the inhaled steroid.