Iota-Carrageenan Inhibits Replication of SARS-CoV-2 and the Respective Variants of Concern Alpha, Beta, Gamma and Delta
Fröba et al.
, Iota-Carrageenan Inhibits Replication of SARS-CoV-2 and the Respective Variants of Concern Alpha, Beta, Gamma..
, International Journal of Molecular Sciences, doi:10.3390/ijms222413202 (In Vitro)
study of iota-, lambda-, and kappa-carrageenan sulfated polysaccharides extracted from red seaweed on SARS-CoV-2 Wuhan type and variants Alpha, Beta, Gamma and Delta, showing that all three carrageenan types had antiviral activity. Iota-carrageenan had comparable IC50
values against all variants. Authors conclude that iota-carrageenan might be effective for prophylaxis and treatment of SARS-CoV-2 for existing and potentially future variants.
9 In Vitro
studies support the efficacy of iota-carrageenan [Alsaidi, Bansal, Bovard, Fröba, Meister, Morokutti-Kurz, Morokutti-Kurz (B), Song, Varese]
Fröba et al., 8 Dec 2021, peer-reviewed, 14 authors.
In Vitro studies are an important part of preclinical research, however results may be very different in vivo.
Abstract: International Journal of
Iota-Carrageenan Inhibits Replication of SARS-CoV-2 and the
Respective Variants of Concern Alpha, Beta, Gamma and Delta
Maria Fröba 1,† , Maximilian Große 1,† , Christian Setz 1,† , Pia Rauch 1 , Janina Auth 1 , Lucas Spanaus 1 ,
Jan Münch 2 , Natalia Ruetalo 3 , Michael Schindler 3 , Martina Morokutti-Kurz 4 , Philipp Graf 4 ,
Eva Prieschl-Grassauer 4 , Andreas Grassauer 4 and Ulrich Schubert 1, *
Citation: Fröba, M.; Große, M.; Setz,
C.; Rauch, P.; Auth, J.; Spanaus, L.;
Münch, J.; Ruetalo, N.; Schindler, M.;
Morokutti-Kurz, M.; et al.
Iota-Carrageenan Inhibits Replication
of SARS-CoV-2 and the Respective
Variants of Concern Alpha, Beta,
Gamma and Delta. Int. J. Mol. Sci.
2021, 22, 13202. https://doi.org/
Academic Editor: Giovanni Maga
Received: 21 October 2021
Accepted: 3 December 2021
Published: 8 December 2021
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Institute of Virology, Friedrich-Alexander University Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany;
Maria.Carolin.Froeba@fau.de (M.F.); Maximilian.Grosse@uk-erlangen.de (M.G.);
Christian.Setz@uk-erlangen.de (C.S.); Pia.Rauch@uk-erlangen.de (P.R.); Janina.Auth@fau.de (J.A.);
Institute of Molecular Virology, Ulm University Medical Center, 89081 Ulm, Germany;
Institute for Medical Virology and Epidemiology of Viral Diseases, University Hospital Tübingen,
72076 Tübingen, Germany; Natalia.Ruetalo-Buschinger@med.uni-tuebingen.de (N.R.);
Marinomed Biotech AG, A-2100 Korneuburg, Austria; Martina.Morokutti-Kurz@marinomed.com (M.M.-K.);
Philipp.Graf@marinomed.com (P.G.); Eva.Prieschl@marinomed.com (E.P.-G.);
Correspondence: Ulrich.Schubert@fau.de; Tel.: +49-9131-85-26478
These authors are contributed equally to this work.
Abstract: The COVID-19 pandemic continues to spread around the world and remains a major
public health threat. Vaccine inefficiency, vaccination breakthroughs and lack of supply, especially in
developing countries, as well as the fact that a non-negligible part of the population either refuse
vaccination or cannot be vaccinated due to age, pre-existing illness or non-response to existing
vaccines intensify this issue. This might also contribute to the emergence of new variants, being
more efficiently transmitted, more virulent and more capable of escaping naturally acquired and
vaccine-induced immunity. Hence, the need of effective and viable prevention options to reduce
viral transmission is of outmost importance. In this study, we investigated the antiviral effect of
iota-, lambda- and kappa-carrageenan, sulfated polysaccharides extracted from red seaweed, on
SARS-CoV-2 Wuhan type and the spreading variants of concern (VOCs) Alpha, Beta, Gamma and
Delta. Carrageenans as part of broadly used nasal and mouth sprays as well as lozenges have
the potential of first line defense to inhibit the infection and transmission of SARS-CoV-2. Here,
we demonstrate by using a SARS-CoV-2 spike pseudotyped lentivirus particles (SSPL) system and
patient-isolated SARS-CoV-2 VOCs to infect transgenic A549ACE2/TMPRSS2 and Calu-3 human
lung cells that all three carrageenan types exert antiviral activity. Iota-carrageenan exhibits antiviral
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