There is a growing body of evidence that the poor outcome of novel coronavirus infection (COVID-19) is related not only to pneumonia but also to thrombotic complications. Among the putative mechanisms accounting for vascular disease, the overproduction of reactive oxygen species (ROS) could play a role. Thus, ROS formation is involved in the process of platelet and clotting activation and could be implicated in the thrombotic process of COVID-19. Studies performed in COVID-19 patients showed over-activation of NOX2 in cells deputed to ROS formation and implicated in thrombosis such as leucocytes and platelets. Furthermore, several types of antioxidants such as albumin and vitamin C and E are lowered in COVID-19 suggesting an imbalance between ROS over-production and low antioxidant status as a mechanism eliciting changes of redox status. However, interventional studies with antioxidants provided inconclusive results, therefore further study is necessary to assess the efficacy of this treatment in COVID-19.
SARS-CoV-2; Oxidative stress; Inflammation; Antioxidants
COVID-19 is a pandemic characterized by severe acute respiratory syndrome (SARS-CoV-2) needing mechanical ventilation and intensive care unit (ICU) treatment. Among the factors predisposing to poor survival, thrombotic complications have been suggested to have an important role [1,2]. Accordingly, clinical studies in COVID-19 showed a high incidence of venous and arterial thromboembolism, which were dependent upon a hypercoagulation state, as depicted by elevated plasma levels of D-dimer [3,4].
There is a growing body of evidence that this tendency to thrombosis may depend upon several mechanisms including activation of platelets or endothelial damage that ultimately favour thrombus growth. Reactive oxygen species (ROS) play a role in the activation of cells implicated in the thrombotic process and there is evidence that pro-oxidant enzyme such as NOX2 are upregulated in SARS-CoV- 2 and correlated with thrombosis . As it would be conceivable, therefore, that antioxidants could have a place in the treatment of SARS-CoV-2, the aim of the review is to explore the “pro and contra” of using antioxidants in SARS-CoV-2.