Sleep hormone melatonin may be a viable treatment option for COVID-19, says study

Melatonin, a hormone which regulates the sleep-wake cycle, and is commonly used as an over-the-counter sleep aid, may be a viable treatment option for COVID-19, according to a study.

The research, published in the journal PLOS Biology, used a novel artificial intelligence (AI) platform to identify possible drugs for COVID-19 repurposing.

Analysis of patient data from US-based Cleveland Clinic's COVID-19 registry also revealed that melatonin usage was associated with a nearly 30 per cent reduced likelihood of testing positive for SARS-CoV-2.

The researchers adjusted their results for age, race, smoking history and various disease comorbidities.

However, the reduced likelihood of testing positive for the virus increased from 30 to 52 per cent for African Americans when adjusted for the same variables, they said.

"It is very important to note these findings do not suggest people should start to take melatonin without consulting their physician," said Feixiong Cheng, an assistant staff at Cleveland, and lead author of the study.

"Large-scale observational studies and randomised controlled trials are critical to validate the clinical benefit of melatonin for patients with COVID-19, but we are excited about the associations put forth in this study and the opportunity to further explore them," Cheng said.

The researchers harnessed network medicine methodologies and large-scale electronic health records from Cleveland Clinic patients to identify clinical manifestations and pathologies common between COVID-19 and other diseases.

They, specifically, measured the proximity between host genes/proteins and those well-associated with 64 other diseases across several disease categories.

In these disease categories, including malignant cancer and pulmonary diseases, closer proximity indicates a higher likelihood of pathological associations between the diseases, the researchers said.

They found, for example, that proteins associated with respiratory distress syndrome and sepsis, two main causes of death in patients with severe COVID-19, were highly connected with multiple SARS-CoV-2 proteins.

"This signals to us, then that a drug already approved to treat these respiratory conditions may have some utility in also treating COVID-19 by acting on those shared biological targets," explained Cheng.

They determined that autoimmune, pulmonary and neurological diseases showed significant network proximity to SARS-CoV-2 genes/proteins and identified 34 drugs as repurposing candidates, melatonin chief among them.

"Recent studies suggest that COVID-19 is a systematic disease impacting multiple cell types, tissues and organs, so knowledge of the complex interplays between the virus and other diseases is key to understanding COVID-19-related complications and identifying repurposable drugs," said Cheng.

"Our study provides a powerful, integrative network medicine strategy to predict disease manifestations associated with COVID-19 and facilitate the search for an effective treatment," he added.