Waterpipe smoking (WPS) has adverse health effects that include endothelial dysfunction with mechanisms involving oxidative stress and inflammation. Nonetheless, there is a scarcity of data on the direct impact of WPS on endothelial function. In this study, we assessed the in vitro effects of waterpipe smoke extract (WPSE) on aortic endothelial cell lines, namely the TeloHAEC. The WPSE markedly caused concentration- and time-dependent decreases in cellular viability. When compared with the control, at a concentration of 20 % and an incubation period of 48 h, the WPSE significantly increased the levels of lactate dehydrogenase, and markers of oxidative stress including thiobarbituric acid reactive substances, superoxide dismutase, catalase, and reduced glutathione. Moreover, the concentrations of proinflammatory cytokine (tumor necrosis factor alpha), and adhesion molecules (E-selectin and intercellular adhesion molecule-1) were also significantly augmented. Likewise, WPSE triggered mitochondrial dysfunction, DNA oxidative damage, as well as apoptosis in TeloHAEC cells. Similarly, cells cultured with WPSE have shown increased expression of phosphorylated nuclear factor-kappaB and hypoxia-inducible factor 1-alpha (HIF-1alpha). In conclusion, our study showed that WPSE triggers endothelial inflammation, oxidative stress, DNA damage, mitochondrial dysfunction, and apoptosis via mechanisms involving the activation of nuclear factor-kappaB and HIF-1alpha. Key words Waterpipe smoking, Aortic endothelial cells, Inflammation, Oxidative Stress.

Department of Physiology College of Medicine and Health Sciences United Arab Emirates University Al Ain United Arab Emirates