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.