El Gazzar Mohamed, El Mezayen Rabab, Marecki John C, Nicolls Mark R, Canastar Andrew, Dreskin Stephen C
Department of Medicine, University of Colorado Health Sciences Center, Denver, CO 80262, USA.
Int Immunopharmacol. 2006 Jul;6(7):1135-42. doi: 10.1016/j.intimp.2006.02.004. Epub 2006 Mar 2.
Thymoquinone (TQ), the main active constituent of the volatile oil extracted from Nigella sativa's seeds, has been reported to have an anti-inflammatory and immune stimulatory effect on bronchial asthma and inflammation. However, little is known about the factors and mechanisms underlying these effects. In the present study, we examined the effect of TQ on airway inflammation in a mouse model of allergic asthma. Intraperitoneal injection of TQ before airway challenge of ovalbumin (OVA)-sensitized mice resulted in a marked decrease in lung eosinophilia and the elevated Th2 cytokines observed after airway challenge with OVA antigen; both in vivo, in the bronchoalveolar lavage (BAL) fluid and in vitro, following stimulation of lung cells with OVA. TQ also decreased the elevated serum levels of OVA-specific IgE and IgG1. Histological examination of lung tissue demonstrated that TQ significantly inhibited allergen-induced lung eosinophilic inflammation and mucus-producing goblet cells. While TQ showed a significant effect in inhibiting IL-4, IL-5 and IL-13 and some effect in inducing IFN-gamma production in the BAL fluid, it did show a slight effect on in vitro production of IL-4 by cultured lung cells stimulated with OVA antigen. These data suggest that TQ attenuates allergic airway inflammation by inhibiting Th2 cytokines and eosinophil infiltration into the airways; thus demonstrating its potential anti-inflammatory role during the allergic response in the lung.
百里醌（TQ）是从黑种草种子中提取的挥发油的主要活性成分，据报道其对支气管哮喘和炎症具有抗炎和免疫刺激作用。然而，对于这些作用背后的因素和机制知之甚少。在本研究中，我们在过敏性哮喘小鼠模型中研究了TQ对气道炎症的影响。在对卵清蛋白（OVA）致敏小鼠进行气道激发前腹腔注射TQ，导致肺嗜酸性粒细胞增多显著减少，且在用OVA抗原进行气道激发后观察到的Th2细胞因子升高也有所降低；无论是在体内支气管肺泡灌洗（BAL）液中，还是在体外，用OVA刺激肺细胞后均是如此。TQ还降低了OVA特异性IgE和IgG1升高的血清水平。肺组织的组织学检查表明，TQ显著抑制了变应原诱导的肺嗜酸性粒细胞炎症和产生黏液的杯状细胞。虽然TQ在抑制BAL液中的IL-4、IL-5和IL-13方面显示出显著效果，在诱导IFN-γ产生方面有一定效果，但对用OVA抗原刺激的培养肺细胞体外产生IL-4的影响较小。这些数据表明，TQ通过抑制Th2细胞因子和嗜酸性粒细胞向气道浸润来减轻过敏性气道炎症；从而证明其在肺部过敏反应期间的潜在抗炎作用。
