Abstract: Life Sciences 250 (2020) 117583 Contents lists available at ScienceDirect Life Sciences journal homepage: www.elsevier.com/locate/lifescie COVID-19: Melatonin as a potential adjuvant treatment a a a a a a a,⁎ T Rui Zhang , Xuebin Wang , Leng Ni , Xiao Di , Baitao Ma , Shuai Niu , Changwei Liu , ⁎⁎ Russel J. Reiterb, a b Department of Vascular Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China Department of Cell Systems and Anatomy, UT Health San Antonio, San Antonio, TX 78229, USA A R T I C LE I N FO A B S T R A C T Keywords: COVID-19 SARS-CoV-2 Melatonin Oxidation-reduction Cytokines Immunomodulation This article summarizes the likely benefits of melatonin in the attenuation of COVID-19 based on its putative pathogenesis. The recent outbreak of COVID-19 has become a pandemic with tens of thousands of infected patients. Based on clinical features, pathology, the pathogenesis of acute respiratory disorder induced by either highly homogenous coronaviruses or other pathogens, the evidence suggests that excessive inflammation, oxidation, and an exaggerated immune response very likely contribute to COVID-19 pathology. This leads to a cytokine storm and subsequent progression to acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) and often death. Melatonin, a well-known anti-inflammatory and anti-oxidative molecule, is protective against ALI/ARDS caused by viral and other pathogens. Melatonin is effective in critical care patients by reducing vessel permeability, anxiety, sedation use, and improving sleeping quality, which might also be beneficial for better clinical outcomes for COVID-19 patients. Notably, melatonin has a high safety profile. There is significant data showing that melatonin limits virus-related diseases and would also likely be beneficial in COVID19 patients. Additional experiments and clinical studies are required to confirm this speculation.