Article at a Glance:
- A new coronavirus called COVID-19 is now the fourth pandemic to affect the globe in the past 100 years.
- Coronaviruses affect mammals, birds and humans – some of which are more dangerous than others.
- The pathology of coronaviruses, including COVID-19, indicates that cytokine storms lead to extremely high levels of proflammatory cells, multi-organ damage and weakened immune systems.
- Melatonin has antioxidant and anti-inflammatory properties that may help the cytokine storms in COVID-19 patients subside when used alongside other anti-inflammatory treatments.
Over the past century, the emergence of influenza viruses has led to four separate human pandemics (global outbreaks of disease), causing widespread illness, death, and disruption. (1) The World Health Organization (WHO) has identified the most recent coronavirus outbreak as SARS-CoV-2, which in turn has led to the spread of the COVID-19 disease that is now affecting hundreds of thousands of people worldwide. (2) According to the epidemiology and pathogenesis of the COVID-19 outbreak, there is some evidence that suggests that melatonin might be useful in managing the symptoms and complications associated with this disease, as well as other coronaviruses. (3)
First, what are coronaviruses?
Coronaviruses are a large group of related viruses that cause diseases in mammals (such as bats, cats, and cattle), birds, and humans. The genetic structure of these pathogens looks like a spiky crown (or corona in Latin), hence their classification name, coronavirus.
According to the Centers for Disease Control and Prevention (CDC), there are currently seven known types of coronaviruses that can infect people, some of which are notably more common or severe than others. In humans, these viruses typically cause mild to moderate respiratory tract infections that present themselves as the common cold. It is rare for animal coronaviruses to infect and spread between people; however, it does happen. In these instances, the viruses not only become more lethal but can also lead to global transmission concerns. That has been the case for SARS-associated coronavirus (SARS-CoV) and MERS-associated coronavirus (MERS-CoV), and it is now also true for new SARS-associated coronavirus (SARS-CoV-2), also known as COVID-19.(4)
Common human coronaviruses:
Other human coronaviruses:
- MERS-CoV (the coronavirus that causes Middle East Respiratory Syndrome)
- SARS-CoV (the coronavirus that causes Severe Acute Respiratory Syndrome)
- SARS-CoV-2 (the latest coronavirus that causes COVID-19)
What is the pathology associated with the COVID-19 coronavirus?
In order to find an effective treatment for coronaviruses, it is critical to understand their causes and effects. Since the sudden outbreak of COVID-19 in Wu Han City, doctors and researchers have discovered several key features in critical COVID-19 patients(5), including:
- sudden deterioration around one to two weeks after onset
- dry cough
- sore throat
- acute respiratory distress syndrome (ARDS)
- lymphocytopenia, or very low levels of lymphocytes (white blood cells), especially natural killer (NK) cells in the blood
- weakened immune system
- overproduction of proinflammatory immune cells, also known as a “cytokine storm”, which contributes to multi-organ dysfunction(6)
- destroyed secondary lymphoid tissues
- spleen atrophy
- vasculitis-like manifestations, or even gangrene in extremities
Currently, antiviral and respiratory supportive therapies are the go-to treatments for severe cases of COVID-19. However, given the presence of ARDS, cytokine storms, and multiple organ damage in critical COVID-19 patients, anti-inflammation treatment may be warranted to help prevent further injury.
What is the relationship between melatonin and treating the COVID-19 coronavirus?
There is scientific evidence that excessive inflammation, oxidation, and an exaggerated immune response very likely contribute to COVID-19 pathology.(7) As researchers race to find an effective vaccine for this virus, there may be other intermediate and anti-inflammatory treatment options to help regulate COVID-19 patients’ immune systems.
Melatonin plays an important role in various functions of the body, including sleep and circadian rhythm regulation, which is directly connected to immune health. This versatile hormone has also been credited for its antioxidant and anti-inflammatory properties. In fact, studies have indicated that melatonin is efficient in preventing cell damage under acute (sepsis, asphyxia in newborns) and chronic states (metabolic and neurodegenerative diseases, cancer, inflammation, aging)(8). Given its anti-stress effect on antigen-activated cells, the research suggests that melatonin could be an effective tool in fighting viral infections (in coordination with other antiviral medications). (9)