Gallium maltolate has in vitro antiviral activity against SARS-CoV-2 and is a potential treatment for COVID-19

Antivir Chem Chemother. 2020 Jan-Dec;28:2040206620983780. doi: 10.1177/2040206620983780.


Background: Gallium has demonstrated strong anti-inflammatory activity in numerous animal studies, and has also demonstrated direct antiviral activity against the influenza A H1N1 virus and the human immunodeficiency virus (HIV). Gallium maltolate (GaM), a small metal-organic coordination complex, has been tested in several Phase 1 clinical trials, in which no dose-limiting or other serious toxicity was reported, even at high daily oral doses for several months at a time. For these reasons, GaM may be considered a potential candidate to treat coronavirus disease 2019 (COVID-19), which is caused by the SARS-CoV-2 virus and can result in severe, sometimes lethal, inflammatory reactions. In this study, we assessed the ability of GaM to inhibit the replication of SARS-CoV-2 in a culture of Vero E6 cells.

Methods: The efficacy of GaM in inhibiting the replication of SARS-CoV-2 was determined in a screening assay using cultured Vero E6 cells. The cytotoxicity of GaM in uninfected cells was determined using the Cell Counting Kit-8 (CCK-8) colorimetric assay.

Results: The results showed that GaM inhibits viral replication in a dose-dependent manner, with the concentration that inhibits replication by 50% (EC50) being about 14 µM. No cytotoxicity was observed at concentrations up to at least 200 µM.

Conclusion: The in vitro activity of GaM against SARS-CoV-2, together with GaM's known anti-inflammatory activity, provide justification for testing GaM in COVID-19 patients.

Keywords: Coronaviridae; SARS; compounds; replication; virus.

MeSH terms

  • Animals
  • Anti-Inflammatory Agents / pharmacology*
  • Anti-Inflammatory Agents / therapeutic use
  • Anti-Inflammatory Agents / toxicity
  • Antiviral Agents / pharmacology*
  • Antiviral Agents / therapeutic use
  • Antiviral Agents / toxicity
  • COVID-19 / drug therapy*
  • Chlorocebus aethiops
  • Dose-Response Relationship, Drug
  • Drug Evaluation, Preclinical
  • Iron / metabolism
  • Organometallic Compounds / pharmacology*
  • Organometallic Compounds / therapeutic use
  • Organometallic Compounds / toxicity
  • Pyrones / pharmacology*
  • Pyrones / therapeutic use
  • Pyrones / toxicity
  • SARS-CoV-2 / drug effects*
  • SARS-CoV-2 / physiology
  • Vero Cells
  • Virus Replication / drug effects


  • Anti-Inflammatory Agents
  • Antiviral Agents
  • Organometallic Compounds
  • Pyrones
  • gallium maltolate
  • Iron

Supplementary concepts

  • COVID-19 drug treatment