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.

The Differential Effect of Cannabidiol on the Composition and Physicochemical Properties of Keratinocyte and Fibroblast Membranes from Psoriatic Patients and Healthy People.

The development of psoriasis is accompanied by oxidative stress, which can modify the components of skin cells. Therefore, the aim of this study was to evaluate the effect of cannabidiol (CBD), an antioxidant and anti-inflammatory phytocannabinoid, on the composition and physicochemical properties of the membranes of healthy and psoriatic keratinocytes and fibroblasts exposed to ultraviolet A (UVA) and ultraviolet B (UVB) radiation. In psoriasis-altered cells, decreased levels of the main groups of phospholipids and increased levels of sialic acid and malondialdehyde (MDA), a lipid peroxidation product, as well as negative charge of cell membranes compared to non-diseased cells, were found. On the other hand, UVA/B radiation increased the levels of phospholipids and MDA in both groups of cells. Moreover, psoriatic cells were characterized by lower levels of sialic acid and negative charge of cell membranes, while non-diseased cells showed the opposite response. The CBD treatment intensified some of the changes (phospholipid content and membrane charge) caused by the radiation of psoriatic cells, while it prevented these changes in the cells of healthy people. The results of this study indicate that CBD can prevent structural and functional changes to the membranes of healthy skin cells during phototherapy for psoriasis.

Rutin and ascorbic acid cooperation in antioxidant and antiapoptotic effect on human skin keratinocytes and fibroblasts exposed to UVA and UVB radiation.

The combination of ascorbic acid and rutin is frequently used in oral preparations. However, despite numerous protective effects of each component individually, their combined effect on ultraviolet (UV)-irradiated skin cells has never been evaluated. The aim of this study was to evaluate the combined effect of ascorbic acid and rutin on human keratinocytes and fibroblasts exposed to UVA and UVB radiation. Skin keratinocytes and fibroblasts exposed to UVA and UVB radiation were treated with ascorbic acid or/and rutin. The total antioxidant properties of both components, as well as their effect on cellular pro- and antioxidant status, lipid and protein oxidation, transmembrane transport, and pro-inflammatory and pro/antiapoptotic protein expression were measured. The combination of ascorbic acid and rutin had higher antioxidant properties compared to the activity of the single compound alone, and showed a stronger effect against UV-induced reactive oxygen species generation. The ascorbic acid and rutin combination also showed increased antioxidant enzyme activity (catalase, superoxide dismutase, thioredoxin reductase), which was impaired following UV irradiation. Moreover, ascorbic acid additional stimulated UV-induced bilitranslocase activity responsible for rutin transport, and therefore favored rutin effect on Nrf2 pathway, simultaneously differentiating the reaction of keratinocytes and fibroblasts. In keratinocytes, Nrf2 is strongly activated, while in fibroblasts decreased Nrf2 activity was observed. Used mixture, also significantly silenced UV-induced expression of pro-inflammatory factor NFκB and pro-apoptotic proteins such as caspases 3, 8, and 9. These results showed that ascorbic acid and rutin are complementary in their antioxidant actions, transport and signaling functions. Their combined antioxidant, antiinflammatory and antiapoptotic actions suggest rutin and ascorbic acid are a potentially cytoprotective team against UV-induced skin damage.