Potential effects of icariin, the Epimedium-derived bioactive compound in the treatment of COVID-19: a hypothesis.

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has affected the world's health systems for more than two years. This disease causes a high mortality rate followed by cytokine storm-induced oxidative stress and acute respiratory distress syndrome (ARDS). Therefore, many drugs have been considered with emphasis on their anti-inflammatory and antioxidant effects in controlling the consequences of SARS-CoV-2 infection. Icariin is a major bioactive pharmaceutical compound derived from Epimedium plants, which is known due to its anti-inflammatory and antioxidant effects. Additionally, the protective effects of icariin have been studied in different pathologies through modulating intracellular pathways. In addition to the potential effect of this compound on inflammation and oxidative stress caused by SARS-CoV-2 infection, it appears to interfere with intracellular pathways involved in viral entry into the cell. Therefore, this paper aims to review the molecular mechanisms of anti-inflammatory and antioxidant properties of icariin, and hypothesizes its potential to inhibit SARS-CoV-2 entry into host cells through modulating the intracellular pathways.