Cytokine storm in COVID-19 and parthenolide: Preclinical evidence

A group of patients with pneumonia caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were reported from China in December 2019. Although several antiviral drugs are widely tested, none of them has been approved as specific antiviral therapy for coronavirus disease 2019 (COVID-19). Accumulating evidence established a hyperinflammatory states or cytokine storm in COVID-19. Among these cytokines, IL-6 plays a key role in cytokine storm and can predict the adverse clinical outcomes and fatality in these patients. Based on the evidence of the significant role of IL-6 in cytokine storm, diabetes mellitus, and cardiovascular diseases as principal comorbidities, it seems that anti-cytokine therapy may be useful in patients with severe COVID-19 to reduce mortality. Recent studies demonstrated that herbal-derived natural products had immunosuppressive and anti-inflammatory properties and exhibited exceptional act on mediators of inflammation. Parthenolide is the principal sesquiterpene lactones and the main biologically active constituent Tanacetum parthenium (commonly known as feverfew) which has could significantly reduce IL-1, IL-2, IL-6, IL-8, and TNF-α production pathways established in several human cell line models in vitro and in vivo studies. Therefore, parthenolide may be one of the herbal candidates for clinical evaluation.