Potential mechanisms by which the oxygen-ozone (O2-O3) therapy could contribute to the treatment against the coronavirus COVID-19

Letter to the editor . European Review for Medical and Pharmacological Sciences . 2020; 24: 4059-4061

L. Valdenassi, M. Franzini, G. Ricevuti, L. Rinaldi, A.C. Galoforo, U. Tirelli

Dear Editor,
On 31 December, at the end of 2019, some cases of pneumonia of unknown etiology were notified to the World Health Organization (WHO) Country Office in China, regarding Wuhan, a city of Hubei province.
.This unknown agent, a few weeks later, was identified as part of the coronavirus family and named 2019 novel Coronavirus. Since then, the epidemic of 2019 Novel
Coronavirus (currently renamed SARS-CoV-2) and causing the disease COVID-19 has expanded from Wuhan throughout China and is being exported to a growing number of countries, with an increasing number of other cases with different rate of transmission.
Biochemical and pharmacological characteristics of ozone provide reasons for considering this molecule useful in the treatment of several viral infections, specifically in the treatment of COVID-19.
Ozone is an oxidant that shows a paradoxical activity when in contact with organic molecules, thus causing a powerful antioxidant response.
In fact, reacting with target substrates in biological fluids (PUFA and GSH), leads to the creation of hydroperoxides and aldehydes. Among them, 4-HNE (4 hydroxylnonenal) is a key element in signal transduction, involved in the upregulation of glutathione, and also, in enhancing the resistance to apoptosis resulting from pro-oxidant agents.
It causes a significant adaptive stress response, by stimulating anti-oxidizing and detoxifyingm enzymes expression.
The 4-HNE partially excreted by the liver and the kidneys, is mostly attached to Cys 34 albumin molecule, GSH and cysteine4. These molecules through circulation easily transfer 4-HNE into the cytoplasm of many cells. Cells cytoplasm contains an inactive transcription factor called Nrf2, bounded to a larger inactive factor containing SH groups called Keap-1, rich in cysteine. When attached to Cys 273 or Cys 288 of Keap-1, 4-HNE releases the key molecule Nrf 2 (Nuclear Factor Erythroid 2-Related Factor 2). This leads to several anti-oxidizing enzymes expression: SOD, GPx, GST, CAT, HO-1, NQO-1, HSP and phase II drug metabolism enzymes. HO-1 catalyzes the degradation of heme to carbon monoxide (CO), which modulates NF-KB determining a decreased pro-inflammatory cytokines expression and anti-inflammatory cytokines direct induction.
Ozone shows an anti-oxidizing and anti-inflammatory action, being NF-KB and Nrf2 transcription agents that modulate the gene expression of pro-inflammatory and anti-inflammatory cytokines.
The accumulation of LOPs and 4-HNE during oxidative stress and in the presence of disease, generates a feedback mechanism which transmits signals and stimulates networks capable of stopping critical oxidation events, common to several conditions.
By reacting with PUFA and aldehydes, ozone generates hydroperoxides and particularly H2O2, it rapidly spreads through cells of the immune system. It also bioregulates signal transduction thus promoting immune responses, modulating interferon and interleukins through the activation of NF-KB, thus increasing the release of cytokines.

This process is part of an endogenic system. In 2002, Lerner and Wentworth have underlined the fact that the human body is able to produce ozone in order to protect itself from infectious agents. This happens by involving neutrophils and antibodies of the immune system which by producing ozone, use its oxidizing power in order to destroy bacteria and viruses present on cell walls.
Tanaka has shown how flu viruses can be inactivated by low concentrations of ozone in the environment and on smooth surfaces. Other studies3-8 have shown that ozone can play a determining role against bacteria, viruses and fungi diseases.
Murray et al have highlighted a decrease of viral infectivity after exposure to ozone. This causes lipidic peroxidation of virus capsid, thus interrupting its reproductive cycle, preventing the necessary contact between the virus and the receptor. Other studies have shown how ozone can inactivate virus strains with or without envelope.
Some strains like HSV-1 (Herpes Simplex type 1 Mc Intyre) and VSV (Vesicular Stomatitis Virus Indiana) after being ozonized have shown a 6 Log 10 reduction of infectious particles in 15 minutes.
VAC strains (Elstree strain) and H1 N1 (Influenza A), have shown a reduction up to 5 Log 10 respectively in 40 and 30 minutes. These results show important changes in different virus strains morphology.
In addition to the anti-oxidizing, anti-inflammatory and anti-viral action, we can consider the relevant activity of stimulation and immune response linked to NFAT, transcription factor linked to different cytokines (IL-2, IL-6, TNF-Alfa e IFN-Gamma) with its support to lymphocytes and macrophages, forming the first line of defense.
Another important characteristic of ozone therapy against COVID-19 infection is shown by the contrast ability toward severe hypoxemia, typical of this virus.
Tests carried out using NIRS spectroscopy, led to increased oxygenation (in the given case, cerebral) shown by an increase of oxygenated hemoglobin and constant values of the non-oxygenated one.
Ozone is a molecule which acts on different levels and in different physiopathological fields. Therefore, we believe that it would be useful to propose this method as a support to the drug therapy currently in treatment against viral infections in general and particularly against COVID-19 and within an integrative medicine approach.

Conflict of Interest
The Authors declare that they have no conflict of interests.

References
1) Pro-MED. PRO/AH/EDR. Undiagnosed pneumonia-China (HU): request for information. Archive Number: 20191230.6864153. 30 Dec 2019. Available at: https://promedmail.org/promed-post/?id=6864153.
2) Perrella A, Carannante N, Berretta M, Rinaldi M, Maturo N, Rinaldi L. Novel Coronavirus 2019 (Sars-CoV2): a global emergency that needs new approaches? Eur Rev Med Pharmacol Sci 2020; 24: 2162-2164.
3) Jiang HJ, Chen N, Shen ZQ, Yin J, Qiu ZG, Miao J, Yang ZW, Shi DY, Wang HR, Wang XW, Li JW, Yang D, Jin M. Inactivation of poliovirus by ozone and the impact of ozone on the viral genome Biomed Environ Sci 2019; 32: 324-333.
4) Silva RA, Garotti JE, Silva RS, Navarini A, Pacheco AM Jr. Analysis of the bactericidal effect of ozone pneumoperitoneum. Acta Cir Bras 2009; 24: 124-127.
5) Rowen R. Ozone therapy as a primary and sole treatment for acute bacteria infection: case report. Med Gas Res 2018; 8: 121-124.
6) Rowen R. Ozone therapy in conjunction with oral antibiotics as a successful primary and sole treatment for chronic septic prosthetic joint: review and case report. Med Gas Res 2018; 3: 8: 67-71.

7) Briè A, Boudaud N, Mssihid A, Loutreul J, Bertrand I, Gantzer C. Inactivation of murine norovirus and hepatitis A virus on fresh raspberries by gaseous ozone treatment. Food Microbiol 2018; 70: 1-6.
8) Murray BK, Ohmine S, Tomer DP, Jensen KJ, Johnson FB, Kirsi JJ, Robison RA, O’Neill KL. Virion disruption by ozone-mediated reactive oxygen species. J Virol Methods 2008; 153: 74-77.
9) Molinari F, Simonetti V, Franzini M, Pandolfi S, Vaiano F, Valdenassi L , Liboni W. Ozone autohemotherapy induces long-term cerebral metabolic changes in multiple sclerosis patients. Int J Immunopathol Pharmacol 2014; 27: 379-389.
10) Berretta M, Della Pepa C, Tralongo P, Fulvi A, Martellotta F, Lleshi A, Nasti G, Fisichella R, Romano C, De Divitiis C, Taibi R, Fiorica F, Di Francia R, Di Mari A, Del Pup L, Crispo A, De Paoli P, Santorelli A, Quagliariello V, Iaffaioli RV, Tirelli U, Facchini G. Use of complementary and alternative medicine (CAM) in cancer patients: an Italian
multicenter survey. Oncotarget 2017; 8: 24401-24414.
11) Tirelli U, Cirrito C, Pavanello M, Piasentin C, Lleshi A, Taibi R. Ozone therapy in 65 patients with fibromyalgia: an effective therapy. Eur Rev Med Pharmacol Sci 2019; 23: 1786-1788.

Letter to the editor