Sulforaphane inhibits the expression of interleukin-6 and interleukin-8 induced in bronchial epithelial IB3-1 cells by exposure to the SARS-CoV-2 Spike protein

•Exposure of bronchial epithelial IB3-1 cells to the SARS-CoV-2 spike protein induces increased release of proteins component of the COVID-19 “cytokine storm”•Treatment with sulforaphane reverses IL-6 and IL-8 upregulation induced by SARS-CoV-2 Spike protein•Sulforaphane-mediated inhibitory effects were, in addition to IL-6 and IL-8, found for PDGF, IL-9, G-CSF, GM-CSF, IFN-γ, MCP-1, MIP-1β•Sulforaphane and sulforaphane-containing phytoproducts should be further evaluated as potential inhibitors of the COVID-19 “cytokine storm” A key clinical feature of COVID-19 is a deep inflammatory state known as “cytokine storm” and characterized by high expression of several cytokines, chemokines and growth factors, including IL-6 and IL-8. A direct consequence of this inflammatory state in the lungs is the Acute Respiratory Distress Syndrome (ARDS), frequently observed in severe COVID-19 patients. The "cytokine storm" is associated with severe forms of COVID-19 and poor prognosis for COVID-19 patients. Sulforaphane (SFN), one of the main components of Brassica oleraceae L. (Brassicaceae or Cruciferae), is known to possess anti-inflammatory effects in tissues from several organs, among which joints, kidneys and lungs. The objective of the present study was to determine whether SFN is able to inhibit IL-6 and IL-8, two key molecules involved in the COVID-19 "cytokine storm". The effects of SFN were studied in vitro on bronchial epithelial IB3-1 cells exposed to the SARS-CoV-2 Spike protein (S-protein). The anti-inflammatory activity of SFN on IL-6 and IL-8 expression has been evaluated by RT-qPCR and Bio-Plex analysis. In our study SFN inhibits, in cultured IB3-1 bronchial cells, the gene expression of IL-6 and IL-8 induced by the S-protein of SARS-CoV-2. This represents the proof-of-principle that SFN may modulate the release of some key proteins of the COVID-19 "cytokine storm". The control of the cytokine storm is one of the major issues in the management of COVID-19 patients. Our study suggests that SFN can be employed in protocols useful to control hyperinflammatory state associated with SARS-CoV-2 infection. [Display omitted]