Effect of lycopene supplementation in oxidative pulmonary stress in experimental acute lung injury

Abstract

Acute respiratory distress syndrome (ARDS) is the most severe form of acute lung injury (ALI). Despite better understanding in the pathophysiology and consequent advancement in therapeutic strategies, mortality rate is still high.The exact mechanism that leads to ARDS is still unknown; however, some evidence suggests that patients with ARDS are exposed to elevated oxidative stress (OS). Oxidative stress results from imbalance between the antioxidant defense system and the generation of reactive oxygen (ROS) or nitrogen (RNS) species and subsequent oxidative damage to biomolecules. Some studies have shown that there is a reduction of antioxidants in patients with ARDS. However, there is no clinical evidence that antioxidant supplementation may reduce mortality or morbidity. Lycopene is an important carotenoid without provitamin A activity. It is found mainly in tomatoes and red fruits. Due to its large number of conjugated double bonds, lycopene is considered one of main antioxidant among carotenoids. Furthermore, it is one of the most potent antioxidants found in the human body, with antioxidant potency approximately a hundred times greater than vitamin E and vitamin C.Mechanical ventilation (MV) is one of the main treatments for ARDS, being able to modify disease progression and reduce mortality. Protective mechanical ventilation is of great importance in ARDS, being able to reduce mortality.Based on the protective effects of high-frequency oscillatory ventilation in ARDS, as well as, potential antioxidant and antiinflammatory lycopene role, our hypothesis is that lycopene provides additional protective effects in ALI experimental model. Thus, the aim of this study is to investigate the effects of lycopene supplementation on lung oxidative stress, evaluated by total antioxidant performance (TAP) assay and oxidative DNA damage assessed by comet assay in an experimental acute lung injury rabbit model ventilated with CMV and HFOV. (AU)