Anti-oxidant effect of heme oxygenase-1 on cigarette smoke-induced vascular injury.

Cigarette smoking, a major independent risk factor of atherosclerosis, can cause oxidative and inflammatory damage of vascular tissue. Heme oxygenase-1 (HO-1) is an endogenous cytoprotective enzyme with an anti-oxidant role in cells. The aim of the present study was to investigate whether HO-1 was able to protect vascular and endothelial cells from the oxidative damage induced by cigarette smoking. It was observed that cigarette smoking was able to induce the generation of the reactive oxygen species (ROS) in carotid arteries of rats. Hemin, a widely used HO-1 inducer, was able to reduce the generation of ROS. In addition, when human umbilical vein endothelial cells (HUVECs) were cultured in the serum of smoking rats, this was able to increase ROS, and the protective effect of hemin was also observed in this system. In conclusion, the present study demonstrated that cigarette smoking causes oxidative damage of vascular cells and HUVECs by inducing the generation of ROS, while HO-1 has an anti-oxidant effect in this course. This also implied that hemin, an inducer of HO-1, may have potential therapeutic applicability in the prevention of vascular diseases caused by cigarette smoking.