Protective effect of thymoquinone on smoking-induced vascular damage: An experimental study in rats

Aim: To investigate the protective effect of thymoquinone on smoking-induced vascular damage in rats. Method: A total of 28 rats were allocated in this experimental study. Rats were equally divided in four groups; as control group (n=7) and study groups including only smoking group (n=7), smoking plus thymoquinone group (n=7) and smoking plus dexamethasone group (n=7). The animals in study groups were subjected to regular cigarette smoke exposure during 2 months, hereby smoking-induced vascular injury model was established in the animals. The thoracic aorta of the animals were surgically resected and then evaluated histopathologically. The prepared aortic tissue samples were analyzed under light microscope in terms of thickness of aortic wall, endothelial continuity and injury as well as degenerative alterations on the endothelium. Results: Mean aortic wall thicknesses were 77.8 and 114.5 μ in only smoking group and smoking plus thymoquinone group respectively, and this difference was statistically significant. In only smoking group partial endothelial damage and complete endothelial damage were observed in 2 and 4 animals respectively whereas in smoking plus thymoquinone group no endothelial damage and partial endothelial damage were observed in 2 and 4 animals respectively. When these groups were compared in terms of endothelial damage, the difference was detected to be statistically significant. Conclusion: Our study demonstrates that thymoquinone has a protective effect on rat endothelium and alleviates the smoking-induced vascular damage in rats.