Carrageenan-containing over-the-counter nasal and oral sprays inhibit SARS-CoV-2 infection of airway epithelial cultures.

Desiree Schütz,Carina Conzelmann,Manfred Frick,Tatjana Weil,Lukas Wettstein,Rüdiger Groß,Giorgio Fois,Jan Münch,Alexander Zelikin,Thomas K Hoffmann,Steffen Stenger,Janis A Müller

doi:10.1152/ajplung.00552.2020

Abstract

Pharmaceutical interventions are urgently needed to prevent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and transmission. As SARS-CoV-2 infects and spreads via the nasopharyngeal airways, we analyzed the antiviral effect of selected nasal and oral sprays on virus infection in vitro. Two nose sprays showed virucidal activity but were cytotoxic precluding further analysis in cell culture. One nasal and one mouth spray suppressed SARS-CoV-2 infection of TMPRSS2-expressing Vero E6 cells and primary differentiated human airway epithelial cultures. The antiviral activity in both sprays could be attributed to polyanionic ι- and κ-carrageenans. Thus, application of carrageenan-containing nasal and mouth sprays may reduce the risk of acquiring SARS-CoV-2 infection and may limit viral spread, warranting further clinical evaluation.

Highlights

The coronavirus disease 2019 (COVID-19)-causing agent, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged at the end of 2019 and quickly spread within the human population around the globe [1]
We explored whether the sprays may inhibit SARSCoV-2 infection
As SARS-CoV-2 primarily enters the human body via infection of nasal epithelial cells [5, 28], we here evaluated whether nasal sprays may exert antiviral activity against this novel pathogen

Summary

INTRODUCTION

The coronavirus disease 2019 (COVID-19)-causing agent, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged at the end of 2019 and quickly spread within the human population around the globe [1]. Sprays applied to the nasal and oral mucosa to soothe symptoms, reduce disease duration, and increase viral clearance of respiratory infections caused by viruses such as rhino-, influenza-, or common cold coronaviruses have been approved and are available as over-the-counter medicine. Two carrageenan-containing sprays inhibited SARS-CoV-2 infection of immortalized cells and, more importantly, fully differentiated human airway epithelial cells resembling a crucial entry portal of the virus, with little to no effect on cell viability. Application of these sprays may help to prevent from acquiring SARS-CoV-2 or suppress viral replication in the nasal epithelia in infected individuals, which may result in attenuated disease and reduced transmission rates. Further evaluation of antiviral nose sprays in clinical studies is warranted

MATERIALS AND METHODS

RESULTS

DISCUSSION

DISCLOSURES