Substantial Toxic Effect of Water-Pipe Smoking on the Early Stage of Embryonic Development.

Background: Water-pipe smoking (WPS) is the most widespread tobacco use in the Middle-East, and is rapidly spreading globally. Smoke from WP contains most of the compounds present in cigarette smoke, although in different proportions. WPS is associated with the risk of several human diseases; however, its impact on the early stage of normal development has not been investigated yet. Thus, in this investigation, we assess the effect of WPS on the embryo at the early stage of development.

Methods: Chicken embryos at 3 days of incubations were used in this study. Meanwhile, we explored the outcome of WPS on angiogenesis using the chorioallantoic membrane (CAM) of the chicken embryos. Finally, quantitative real-time polymerase chain reaction was used to study the regulation of some key control genes of cell proliferation, apoptosis, and migration.

Results: Our data reveal that WPS inhibits angiogenesis of the CAM and in embryos in comparison with their matched controls; in addition, WPS-exposed embryos show slight reduction in their sizes. We also noted that around 80% of WPS-exposed embryos die before 10 days of incubation. More significantly, WPS induces upregulations of BCL-2, Caspase-8, ATF-3, INHIB-A, and Cadherin 6 genes, which are important key regulators of cell apoptosis, proliferation, and migration.

Conclusion: Our data reveal, for the first time, that WPS has very toxic effects during the early stage of embryogenesis. Thus, we believe that further studies are required to elucidate the pathogenic effect of WPS on human health especially on the embryo at the early stage of its development.

Implications: This investigation addresses an important gap on the outcome of WPS during the early stage of embryogenesis. Data of this study point out that WPS can have a very toxic effect on the embryo at this stage. Additionally, results from this report display for the first time that WPS can damage normal angiogenesis of the embryo thus provoking a significant number of embryonic death. Moreover, this study reveals that this effect can occur via the deregulation of several genes related to cell apoptosis, proliferation, and migration.