Even after virus elimination, numerous sequelae of coronavirus disease 2019 (COVID-19) persist. Based on accumulating evidence, large amounts of proinflammatory cytokines are released to drive COVID-19 progression, severity, and mortality, and their levels remain elevated after the acute phase of COVID-19, playing a central role in the disease' sequelae. In this manner, bronchial epithelial cells are the first cells hyperactivated by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), leading to massive cytokine release, triggering the hyperactivation of leukocytes and other cells, and mediating COVID-19 sequelae. Therefore, proinflammatory cytokine production is initiated by the host. This in vitro study tested the hypothesis that ImmuneRecov™, a nutritional blend, inhibits the SARS-CoV-2-induced hyperactivation of human bronchial epithelial cells (BEAS-2B). BEAS-2B (5x104/mL/well) cells were cocultivated with 1 ml of blood from a SARS-CoV-2-infected patient for 4 h, and the nutritional blend (1 µg/mL) was added in the first minute of coculture. After 4 h, the cells were recovered and used for analyses of cytotoxicity with the (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) (MTT) assay and the expression of the IL-1β, IL-6, and IL-10 mRNAs. The supernatant was collected to measure cytokine levels. SARS-CoV-2 incubation resulted in increased levels of IL-1β and IL-6 in BEAS-2B cells (p < 0.001). Treatment with the nutritional blend resulted in reduced levels of the proinflammatory cytokines IL-1β and IL-6 (p < 0.001) and increased levels of the anti-inflammatory cytokine IL-10 (p < 0.001). Additionally, the nutritional blend reduced the expression of the IL-1β and IL-6 mRNAs in SARS-CoV-2-stimulated cells and increased the expression of the IL-10 and IFN-γ mRNAs. In conclusion, the nutritional blend exerts important anti-inflammatory effects on cells in the context of SARS-CoV-2 infection.
Keywords: COVID-19; SARS-CoV-2; cytokines; epithelium; inflammation.