title: Anti-inflammatory effect of thymoquinone in a mouse model of allergic lung inflammation.
abstract: 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.
authors.affiliation: Department of Medicine, University of Colorado Health Sciences Center, Denver, CO 80262, USA. mohamed.elgazzar@uchsc.edu
authors.forename: Mohamed
authors.initials: M
authors.lastname: El Gazzar
authors.forename: Rabab
authors.initials: R
authors.lastname: El Mezayen
authors.forename: John C
authors.initials: JC
authors.lastname: Marecki
authors.forename: Mark R
authors.initials: MR
authors.lastname: Nicolls
authors.forename: Andrew
authors.initials: A
authors.lastname: Canastar
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Dreskin
mesh_terms: D000485:Allergens / Q000494:pharmacology; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D016227:Benzoquinones / Q000494:pharmacology*; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D016207:Cytokines / Q000276:immunology; D004195:Disease Models, Animal; D005260:Female; D020397:Goblet Cells / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D007073:Immunoglobulin E / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007958:Leukocyte Count; D008168:Lung / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010047:Ovalbumin / Q000494:pharmacology; D011014:Pneumonia / Q000188:drug therapy*; D012130:Respiratory Hypersensitivity / Q000188:drug therapy*; D018418:Th2 Cells / Q000276:immunology
chemical_list: D000485:Allergens; D000893:Anti-Inflammatory Agents; D016227:Benzoquinones; D016207:Cytokines; D007074:Immunoglobulin G; D007073:Immunoglobulin E; D010047:Ovalbumin; C003466:thymoquinone