Comment on Melatonin as a potential adjuvant treatment for COVID-19

Therapeutic Benefits of Melatonin against COVID-19

The assumption of the pineal hormone melatonin as a therapeutic use for COVID-19-affected people seems promising. Its intake has shown significant improvement in the patients' conditions. Higher melatonin titers in children may provide a protective shield against this disease. The hormone melatonin works as an anti-inflammatory, antioxidant, immunomodulator, and strategically slows down the cytokine release which is observed in the COVID-19 disease, thereby improving the overall health of afflicted patients. The medical community is expected shortly to use remedial attributes like anti-inflammatory, antioxidant, antivirals, etc., of melatonin in the successful prevention and cure of COVID-19 morbidity. Thus, the administration of melatonin seems auspicious in the cure and prevention of this COVID-19 fatality. Moreover, melatonin does not seem to reduce the efficiency of approved vaccines against the SARS-CoV-2 virus. Melatonin increases the production of inflammatory cytokines and Th1 and enhances both humoral and cell-mediated responses. Through the enhanced humoral immunity, melatonin exhibits antiviral activities by suppressing multiple inflammatory products such as IL-6, IL1β, and tumor necrosis factor α, which are immediately released during lung injury of severe COVID-19. Hence, the novel use of melatonin along with other antivirals as an early treatment option against COVID-19 infection is suggested. Here, we have chalked out the invasion mechanisms and appropriate implications of the latest findings concerned with melatonin against the virus SARS-CoV-2. Nevertheless, within the setting of a clinical intervention, the promising compounds must go through a series of studies before their recommendation. In the clinical field, this is done in a time-ordered sequence, in line with the phase label affixed to proper protocol of trials: phase I-phase II and the final phase III. Nevertheless, while medical recommendations can only be made on the basis of reassuring evidence, there are still three issues worth considering before implementation: representativeness, validity, and lastly generalizability.

Phytomelatonin: a potential phytotherapeutic intervention on COVID-19-exposed individuals

Phytomelatonin is a pleiotropic molecule that originated in higher plants with many diverse actions and is primarily an antioxidant. The recent identification and advancement of phytomelatonin unraveled the potential of this modulatory molecule being considered a new plant hormone, suggesting its relevance in treating respiratory infections, including COVID-19. Besides, this molecule is also involved in multiple hormonal, physiological, and biological processes at different levels of cell organization and has been marked for its ability to cross the blood-brain barrier and prominent antioxidant effects, reducing mitochondrial electron leakage, up-regulating antioxidant enzymes, acting as a free radical scavenger, and interfering with pro-inflammatory signaling pathways as seen in mood swings, body temperature, sleep, cancer, cardiac rhythms, and immunological regulation modulators. However, due to its diversity, availability, affordability, convenience, and high safety profile, phytomelatonin has also been suggested as a natural adjuvant. This review discussed the origin, content in various plant species, processes of extraction, and detection and therapeutic potentials of phytomelatonin in treating COVID-19-exposed individuals.

Pathophysiology of Acute Respiratory Failure by CoV-2 Infection: Role of Oxidative Stress, Endothelial Dysfunction and Obesity

Coronavirus disease 2019 (COVID-19) due to CoV-2 (coronavirus type 2) virus possess a particular risk of developing acute respiratory distress syndrome (ARDS) or SARS (severe acute respiratory syndrome coronavirus 2)-CoV2 in people with pre-existing conditions related to endothelial dysfunction and increased pro-inflammatory and pro-oxidant state. In between these conditions, chronic systemic inflammation related to obese patients is associated with the development of atherosclerosis, type 2 diabetes, and hypertension, comorbidities that adversely affect the clinical outcome in critical patients with COVID-19. Obesity affects up to 40% of the general population in the USA and more than 30% of the adult population in Chile. Until April 2021, 1,019,478 people have been infected, with 23,524 deaths. Given the coexistence of this worldwide obesity epidemic, COVID-19 negative outcomes are seriously enhanced in the current scenario. On the other hand, obesity is characterized by endothelial dysfunction observed in different vascular beds, an alteration which can be associated with impaired vasodilation, oxidative stress, and inflammatory events. Emerging evidence shows that obesity-related conditions such as endothelial dysfunction are associated with detrimental outcomes for COVID-19 evolution, especially if the patient derives to Intensive Care Units (ICU). This implies the need to understand the pathophysiology of the infection in the obese population, in order to propose therapeutic alternatives and public health policies, especially if the virus remains in the population. In this review, we summarize evidence about the pathogeny of Cov-2 infection in obese individuals and discuss how obesity-associated inflammatory and prooxidant status increase the severity of COVID-19.

Melatonin Reduces Oxidative Stress in the Right Ventricle of Newborn Sheep Gestated under Chronic Hypoxia

Pulmonary arterial hypertension of newborns (PAHN) constitutes a critical condition involving both severe cardiac remodeling and right ventricle dysfunction. One main cause of this condition is perinatal hypoxia and oxidative stress. Thus, it is a public health concern for populations living above 2500 m and in cases of intrauterine chronic hypoxia in lowlands. Still, pulmonary and cardiac impairments in PAHN lack effective treatments. Previously we have shown the beneficial effects of neonatal melatonin treatment on pulmonary circulation. However, the cardiac effects of this treatment are unknown. In this study, we assessed whether melatonin improves cardiac function and modulates right ventricle (RV) oxidative stress. Ten lambs were gestated, born, and raised at 3600 m. Lambs were divided in two groups. One received daily vehicle as control, and another received daily melatonin (1 mg·kg^-1·d^-1) for 21 days. Daily cardiovascular measurements were recorded and, at 29 days old, cardiac tissue was collected. Melatonin decreased pulmonary arterial pressure at the end of the experimental period. In addition, melatonin enhanced manganese superoxide dismutase and catalase (CAT) expression, while increasing CAT activity in RV. This was associated with a decrease in superoxide anion generation at the mitochondria and NADPH oxidases in RV. Finally, these effects were associated with a marked decrease of oxidative stress markers in RV. These findings support the cardioprotective effects of an oral administration of melatonin in newborns that suffer from developmental chronic hypoxia.

The Coronavirus Disease 2019 (COVID-19): Key Emphasis on Melatonin Safety and Therapeutic Efficacy

Viral infections constitute a tectonic convulsion in the normophysiology of the hosts. The current coronavirus disease 2019 (COVID-19) pandemic is not an exception, and therefore the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, like any other invading microbe, enacts a generalized immune response once the virus contacts the body. Melatonin is a systemic dealer that does not overlook any homeostasis disturbance, which consequently brings into play its cooperative triad, antioxidant, anti-inflammatory, and immune-stimulant backbone, to stop the infective cycle of SARS-CoV-2 or any other endogenous or exogenous threat. In COVID-19, the corporal propagation of SARS-CoV-2 involves an exacerbated oxidative activity and therefore the overproduction of great amounts of reactive oxygen and nitrogen species (RONS). The endorsement of melatonin as a possible protective agent against the current pandemic is indirectly supported by its widely demonstrated beneficial role in preclinical and clinical studies of other respiratory diseases. In addition, focusing the therapeutic action on strengthening the host protection responses in critical phases of the infective cycle makes it likely that multi-tasking melatonin will provide multi-protection, maintaining its efficacy against the virus variants that are already emerging and will emerge as long as SARS-CoV-2 continues to circulate among us.

Possible role of exogenous melatonin in preventing more serious COVID-19 infection in patients with type 2 diabetes mellitus

COVID-19 infection is more severe in patients with type 2 diabetes mellitus (DM2). The severity of this viral infection is associated with an intense inflammatory activity. DM2 is a disease that also determines a greater degree of systemic inflammation. This is due to hyperglycemia, the higher prevalence of sleep disorders and also the low levels of melatonin, a substance with anti-inflammatory actions, in these patients. In this article, we suggest that exogenous melatonin may have an important anti-inflammatory role in preventing severe forms of COVID -19 in patients with DM2.

Melatonin for the Early Treatment of COVID-19: A Narrative Review of Current Evidence and Possible Efficacy

OBJECTIVE

To discuss the use of melatonin as an early treatment option on the first day of diagnosis for COVID-19.

METHODS

Medical Subject Headings terms "COVID-19" and "viral diseases" were manually searched on PubMed, and relevant articles were included.

RESULTS

The results showed that melatonin acts to reduce reactive oxygen species-mediated damage, cytokine-induced inflammation, and lymphopenia in viral diseases similar to COVID-19.

CONCLUSION

These conclusions provide evidence for potential benefits in melatonin use for COVID-19 treatment as early as the day of diagnosis.

Pineal hormone melatonin as an adjuvant treatment for COVID‑19 (Review)

The beneficial properties of the pineal hormone, melatonin, as a neuroprotective and cardioprotective agent, have been previously identified. Furthermore, melatonin plays essential roles in biological rhythms resynchronization, sleep initiation/maintenance and metabolic, ocular, rheumatological diseases. In addition to these functions, melatonin is known to exert immunomodulation, anti-inflammatory and anti-oxidative effects. Due to these properties, coupled with its non-toxic nature, melatonin has been suggested to limit viral infections; however, melatonin cannot be classified as a viricidal drug. In addition, the recent increase in the number of clinical trials on melatonin's role, as an adjuvant treatment for COVID-19, has resurged the interest of the scientific community in this hormone. The present short review aimed to improve the understanding of the antiviral/anti-COVID-19 profile of melatonin and the clinical trials that have recently been conducted, with respect to its co-administration in treating individuals with COVID-19.

Familiar Dermatologic Drugs as Therapies for COVID-19

Researchers the world over are working to find the treatments needed to reduce the negative effects of coronavirus disease 2019 (COVID-19) and improve the current prognosis of patients. Several drugs that are often used in dermatology are among the potentially useful treatments: ivermectin, antiandrogenic agents, melatonin, and the antimalarial drugs chloroquine and hydroxychloroquine. These and other agents, some of which have proven controversial, are being scrutinized by the scientific community. We briefly review the aforementioned dermatologic drugs and describe the most recent findings relevant to their use against COVID-19.

Familiar dermatologic drugs as therapies for COVID-19

Researchers the world over are working to find the treatments needed to reduce the negative effects of coronavirus disease 2019 (COVID-19) and improve the current prognosis of patients. Several drugs that are often used in dermatology are among the potentially useful treatments: ivermectin, antiandrogenic agents, melatonin, and the antimalarial drugs chloroquine and hydroxychloroquine. These and other agents, some of which have proven controversial, are being scrutinized by the scientific community. We briefly review the aforementioned dermatologic drugs and describe the most recent findings relevant to their use against COVID-19.

Melatonin, aging, and COVID-19: Could melatonin be beneficial for COVID-19 treatment in the elderly?

The aim of this review is to summarize current studies on the relationship between melatonin and aging. Nowadays, age-related diseases come into prominence, and identifying age-related changes and developing proper therapeutic approaches are counted as some of the major issues regarding community health. Melatonin is the main hormone of the pineal gland. Melatonin is known to influence many biological processes in the body, including circadian rhythms, the immune system, and neuroendocrine and cardiovascular functions.Melatoninrhythms also reflect the biological process of aging. Aging is an extremely complex and multifactorial process. Melatonin levels decline considerably with aging and its decline is associated with several age-related diseases. Aging is closely associated with oxidative damage and mitochondrial dysfunction. Free radical reactions initiated by the mitochondria constitute the inherent aging process. Melatonin plays a pivotal role in preventing age-related oxidative stress. Coronavirus disease 2019 (COVID-19) fatality rates increase with chronic diseases and age, where melatonin levels decrease. For this reason, melatonin supplementation in elderly could be beneficial in COVID-19 treatment. Therefore, studies on the usage of melatonin in COVID-19 treatment are needed.

Mitochondria at the Crossroads of Physiology and Pathology

Mitochondria play a crucial role in cell life and death by regulating bioenergetic and biosynthetic pathways. They are able to adapt rapidly to different microenvironmental stressors by accommodating the metabolic and biosynthetic needs of the cell. Mounting evidence places mitochondrial dysfunction at the core of several diseases, notably in the context of pathologies of the cardiovascular and central nervous system. In addition, mutations in some mitochondrial proteins are bona fide cancer drivers. Better understanding of the functions of these multifaceted organelles and their components may finetune our knowledge on the molecular bases of certain diseases and suggest new therapeutic avenues.