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Botanical Drugs and Supplements Affecting the Immune Response in the Time of COVID-19: Implications for Research and Clinical Practice
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  • Thomas Brendler,
  • Ahmed Al-Harrasi,
  • Rudolf Bauer,
  • Stefan Gafner,
  • Mary Hardy,
  • Michael Heinrich,
  • Hossein Hosseinzadeh,
  • Angelo Izzo,
  • Martin Michaelis,
  • Marjan Nassiri-Asl,
  • Alexander Panossian,
  • Solomon Wasser,
  • Elizabeth Williamson
Thomas Brendler
University of Johannesburg

Corresponding Author:[email protected]

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Ahmed Al-Harrasi
University of Nizwa
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Rudolf Bauer
University of Graz
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Stefan Gafner
American Botanical Council
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Mary Hardy
Association of Integrative and Holistic Medicine
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Michael Heinrich
UCL School of Pharmacy
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Hossein Hosseinzadeh
School of Pharmacy, Mashhad University of Medical Sciences,
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Angelo Izzo
University of Naples
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Martin Michaelis
University of Kent
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Marjan Nassiri-Asl
Shahid Beheshti University of Medical Sciences
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Alexander Panossian
Phytomed AB
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Solomon Wasser
University of Haifa
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Elizabeth Williamson
University of Reading - Whiteknights Campus
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In times of health crisis, including the current COVID-19 pandemic, the potential benefit of botanical drugs and supplements emerges as a focus of attention, although controversial efficacy claims are rightly a concern. Phytotherapy has an established role in everyday selfcare and health care, and since botanical preparations contain many chemical constituents rather than single compounds, challenges arise in demonstrating efficacy and safety. However, there is ample traditional, empirical and clinical evidence that botanicals can offer some protection and alleviation of disease symptoms as well as promoting general well-being. Newly emerging viral infections, specifically COVID-19, represent a unique challenge in their novelty and absence of established antiviral treatment or immunization. We discuss here the roles and limitations of phytotherapy in helping to prevent and address viral infections, and specifically regarding their effects on immune response. Botanicals with a documented immunomodulatory, immunostimulatory, and anti-inflammatory effect include adaptogens, Boswellia spp., Curcuma longa, Echinacea spp., Glycyrrhiza spp., medicinal fungi, Pelargonium sidoides, salicylate-yielding herbs, and Sambucus spp. We further provide a clinical perspective on applications and safety of these herbs in prevention, onset, progression, and convalescence from respiratory viral infections.