Propolis blocks the ACE receptors which are important for the penetration of viruses in the cells/vascular system.

A polyphenol mixture from poplar-type propolis for uncomplicated upper respiratory tract infections (2021) (Italy)

Phenolic Profile, Antioxidant Capacities and Enzymatic Inhibitory Activities of Propolis (2020)(Spain)

Structure and antioxidant activity of polyphenols from propolis (2014)(Poland)

Effects of propolis flavonoids on virus infectivity and replication (1990, Italy)

Antimicrobial, antifungal and antiviral substances from various types of propolis (2017)(Poland)

Immune activation and radioprotection by propolis

Immunomodulatory action of propolis. VI. Influence of a water soluble derivative on complement activity in vitro

Immunomodulatory Properties of Green Propolis

Propolis and the immune system. A review. JM Sforcin (2007)(Brazil)

Propolis induces Ca2+ signaling in immune cells

Quercetin against porcine epidemic diarrhea virus (2011) (Korea)

Geopropolis from Scaptotrigona postica as anti herpes virus (2015)(Brazil)

Melittin: a venom-derived peptide with promising anti-viral properties – Hamed Memariani, Mojtaba Memariani,  Hamideh Moravvej & Mohammad Shahidi-Dadras, European Journal of Clinical Microbiology & Infectious Diseases volume 39, pages 5–17(2020)

Bee Venom – Overview of Main Compounds and Bioactivities for therapeutic interests (2019 (Lebanon, France)

Cytolytic nanoparticles with melittine attenuate HIV-1 infectivity (2013(USA)

Bee venom and its components against viruses (2016) (Korea, Bangladesh)

Melittin against hepatocarcinoma (2015) (China)

Antiviral peptides against influenza viruses (2015) (Slovakia and Czech Republic)

Induction of IFN-γ cytokine response against hepatitis B surface antigen using melittin (2014) (Iran)

Bee products against herpes virus (Munstedt Karsten)(2019)

Volatile Compounds in Honey. Christy E. Manyi-Loh et al. (South Africa)(2011)

Therapeutic Potential of Brassinosteroids in Biomedical and Clinical Research (2020)(India, China, Italy)

Antiviral essential oils (2020) (Algeria)

Nigella sativa (black cumin) and honey against COVID-19 (2020)(Saudi Arabia, Egypt)

Nigella sativa compounds against Covid-19 (2020)(Algeria)

Nigella sativa, Anthemis hyalina and Citrus sinensis against coronavirus (2014) (Turkey)

Essential oils of aromatic plants with antibacterial, antifungal, antiviral, and cytotoxic properties (2009)(Switzerland)

Houttuynia cordata and quercetin against viruses (2016, Singapore)

Polyphenols from Broussonetia papyrifera as coronavirus protease inhibitors

The potential chemical structure of anti-SARS-CoV-2 RNA-dependent RNA polymerase

The potential chemical structure of anti-SARS-CoV-2 RNA-dependent RNA polymerase

Torreya nucifera, apigenine, luteoline and quercetine against SARS virus (2010)(Korea)

Withanone and Caffeic Acid Phenethyl Ester against SARS CoV 2 (2020) (India, Japan)

Traditional Chinese medicine for COVID-19 treatment

Efficacy of ethanol against viruses in hand disinfection ((2018) (Germany)

Note from the editor:

Most of the propolis tinctures from the market are made with alcohol from 70 to 96%.

Their use in the form of pharyngeal (throat) spray and nebulization (after dilution with honey which is acidic and enriched with essential oils that have a broad antiviral spectrum, see above) is therefore recommended.

Even if the viruses are not completely destroyed (because the concentration of alcohol on the respiratory mucosas is lower than the one from the laboratory tests), the fact that they may be damaged in their structure and/or have their virulence decreased, may be very useful at least from the preventative point of view.