Efficacy of thymoquinone in the treatment of experimental lipopolysaccharide-induced acute lung injury

Introduction
Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are acute onset syndromes affecting the lungs, which develop for several reasons and are characterized by hypoxemia and diffuse lung infiltration. The activity of thymoquinone (TQ) is known in acute lung injury. It is considered that it could be effective in ALI/ARDS treatment by ensuring possible COX-2 inhibition.By this study was to show the protective activity of TQ in lipopolysaccharide (LPS) induced acute lung injury.

Material and methods
A total of 28 BALB/c male mice were randomized to 4 groups of 7 as the Control group, TQ group (3 mg/kg), LPS group (5 mg/kg) and TQ treatment group. TQ was administered intraperitoneally 1 hour before the intratracheal administration of LPS (5 mg/kg). The mice were sacrificed 6 hours after the LPS administration and the lungs were extracted for histopathological examination. All experimental procedures complied with the requirements of the Animal Care and Ethics Committee of Dokuz Eylul University.

Results
When all the study groups were compared, significant differences were found between the groups in terms of the degrees of neutrophil migration (p = 0.042), intra-alveolar hemorrhage (p = 0.004) and alveolar destruction (p < 0.0006). A significant recovery was observed in the lung histopathological changes (neutrophil migration, intra-alveolar hemorrhage and alveolar destruction) in the TQ treatment group.

Conclusions
The results of this study showed that TQ may have a protective effect against LPS-induced acute lung injury. The possible mechanism could be considered to be cyclooxygenase 2 (COX-2) inhibition.