Niclosamide as a potent anti-SARS-CoV-2 agent
Given niclosamide’s potent antiviral activity within the beta-coronavirus family, it became apparent that it could be a potent antiviral against SARS-CoV-2. A study by Jeon et al., (2020) testing 3000 FDA approved drugs and other well characterized molecules identified niclosamide as the most potent inhibitor of SARS-CoV-2 in Vero cells, with a 40-fold higher potency than remdesivir. Furthermore, Weiss et al., (2021) showed that niclosamide’s potency is conserved against the alpha and beta SARS-CoV-2 variant in Vero TMPRSS2 cells and validated niclosamide’s strong antiviral activity in a human airway epithelial model. Niclosamide has also been shown to inhibit SARS-CoV-2in vivo . Specifically, an inhaled niclosamide formulation was developed and tested in a murine infection model (Brunaugh et al., 2021). Intranasal administration of niclosamide to coronavirus infected mice improved survival and significantly reduced viral loads. Intranasal niclosamide administration exhibited potent properties as an anti-MRSA bacteriostatic agent and modulated various inflammatory cytokines such as IL-1β, IL-6 and TNF-α. These findings suggest that niclosamide could also address secondary bacterial infections, which is one of the leading causes of death in COVID-19 patients.