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Cathepsin inhibitors nitroxoline and its derivatives inhibit SARS-CoV-2 infection

Milan Bonotto et al., Antiviral Research, doi:10.1016/j.antiviral.2023.105655
Jun 2023  
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HCQ for COVID-19
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In Vitro study showing that CatB inhibitors including nitroxoline and its derivatives significantly impair SARS-CoV-2 infection. Authors use HCQ as a control. HCQ can indirectly inhibit CatB by elevating the pH of endosomes. Other research shows that SARS-CoV-2 infection requires acidic pH Kreutzberger.
Milan Bonotto et al., 30 Jun 2023, peer-reviewed, 8 authors. Contact:,
In Vitro studies are an important part of preclinical research, however results may be very different in vivo.
This PaperHCQAll
Cathepsin inhibitors nitroxoline and its derivatives inhibit SARS-CoV-2 infection
Rafaela Milan Bonotto, Ana Mitrović, Izidor Sosič, Pamela Martinez-Orellana, Federica Dattola, Stanislav Gobec, Janko Kos, PhD Alessandro Marcello
Antiviral Research, doi:10.1016/j.antiviral.2023.105655
This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Declaration of interests ☒ The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. ☐The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: On behalf of the authors: Alessandro Marcello Head, Laboratory of Molecular Virology International Centre for Genetic Engineering and Biotechnology (ICGEB) Padriciano, 99, 34149 Trieste, ITALY Email: Janko Kos Faculty of Pharmacy University of Ljubljana Aškerčeva cesta 7, 1000 Ljubljana, Slovenia Email: The authors declare the international application number PCT/EP2021/083960 "8-hydroxyquinoline cysteine protease inhibitors for use in the prevention and/or treatment of a coronavirus disease". The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. J o u r n a l P r e -p r o o f
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