The Impact of Severe COVID-19 on Plasma Antioxidants

Several studies suggested the association of COVID-19 with systemic oxidative stress, in particular with lipid peroxidation and vascular stress. Therefore, this study aimed to evaluate the antioxidant signaling in the plasma of eighty-eight patients upon admission to the Clinical Hospital Dubrava in Zagreb, of which twenty-two died within a week, while the other recovered. The differences between the deceased and the survivors were found, especially in the reduction of superoxide dismutases (SOD-1 and SOD-2) activity, which was accompanied by the alteration in glutathione-dependent system and the intensification of the thioredoxin-dependent system. Reduced levels of non-enzymatic antioxidants, especially tocopherol, were also observed, which correlated with enhanced lipid peroxidation (determined by 4-hydroxynonenal (4-HNE) and neuroprostane levels) and oxidative modifications of proteins assessed as 4-HNE-protein adducts and carbonyl groups. These findings confirm the onset of systemic oxidative stress in patients with severe SARS-CoV-2, especially those who died from COVID-19, as manifested by strongly reduced tocopherol level and SOD activity associated with lipid peroxidation. Therefore, we propose that preventive and/or supplementary use of antioxidants, especially of lipophilic nature, could be beneficial for the treatment of COVID-19 patients.

Automated summary

COVID-19 is associated with systemic oxidative stress, particularly lipid peroxidation and vascular stress. This study found differences in antioxidant signaling between deceased and recovered COVID-19 patients, including reduced activity of superoxide dismutases (SOD) and alterations in the glutathione-dependent and thioredoxin-dependent systems. Reduced levels of non-enzymatic antioxidants, such as tocopherol, were also observed, along with increased lipid peroxidation and oxidative modifications of proteins. These findings confirm the presence of systemic oxidative stress in severe SARS-CoV-2 patients, especially those who died from COVID-19. The study suggests that the preventive or supplementary use of antioxidants, particularly lipophilic antioxidants, may be beneficial for the treatment of COVID-19 patients.