Short-term pulmonary effects of nose-only water pipe (shisha) smoking exposure in mice

Abstract

Introduction: Water pipe smoking (WPS) is a major type of smoking in Middle Eastern countries, and is increasing in popularity in Western countries. It is perceived as relatively safe; however, the underlying pathophysiological mechanisms related to the short-term pulmonary effects of WPS exposure are not understood. Objectives: The aim of this study was to investigate the short-term pulmonary effects of nose-only exposure to mainstream WPS generated by commercially available honey-flavoured tobacco. Materials and methods: BALB/c mice were exposed to WPS for 30 minutes/day for 5 days. Control mice were exposed to atmospheric air only. We measured airway resistance using forced oscillation technique, and pulmonary inflammation was evaluated histopathologically and by biochemical analysis of bronchoalveolar lavage (BAL) fluid and lung tissue. Lung oxidative stress was evaluated biochemically by measuring the level of reactive oxygen species (ROS), reduced glutathione (GSH), catalase and superoxide dismutase (SOD). Results: Mice exposed to WPS showed a significant increase in the number of neutrophils and lymphocytes. Moreover, total protein, lactate dehydrogenase and endothelin levels were augmented in BAL fluid. Tumour necrosis factor α and interleukin 6 concentrations were significantly increased in lung following exposure to WPS. ROS in lung tissue was significantly increased whereas the level and activity of antioxidants, including GSH, catalase and SOD, were significantly decreased after WPS exposure, indicating oxidative stress. By contrast, airway resistance was not increased in WPS exposure. Conclusion: Our data indicate that short-term, nose-only exposure to WPS causes lung inflammation and oxidative stress without affecting pulmonary function. These data provide information on the initial steps involved in the respiratory effects of WPS, which constitute the underlying causal chain of reactions leading to the long-term effects of WPS. Acknowledgements: Professor Abderrahim Nemmar for supervising this project.