The COVID-19 pandemic is caused by SARS-CoV-2 and is leading to the worst health crisis of this century. It emerged in China during late 2019 and rapidly spread all over the world, producing a broad spectrum of clinical disease severity, ranging from asymptomatic infection to death (4.3 million victims so far). Consequently, the scientific research is devoted to investigating the mechanisms of COVID-19 pathogenesis to both identify specific therapeutic drugs and develop vaccines. Although immunological mechanisms driving COVID-19 pathogenesis are still largely unknown, new understanding has emerged about the innate and adaptive immune responses elicited in SARS-CoV-2 infection, which are mainly focused on the dysregulated inflammatory response in severe COVID-19. Polyphenols are naturally occurring products with immunomodulatory activity, playing a relevant role in reducing inflammation and preventing the onset of serious chronic diseases. Mainly based on data collected before the appearance of SARS-CoV-2, polyphenols have been recently suggested as promising agents to fight COVID-19, and some clinical trials have already been approved with polyphenols to treat COVID-19. The aim of this review is to analyze and discuss the in vitro and in vivo research on the immunomodulatory activity of quercetin as a research model of polyphenols, focusing on research that addresses issues related to the dysregulated immune response in severe COVID-19. From this analysis, it emerges that although encouraging data are present, they are still insufficient to recommend polyphenols as potential immunomodulatory agents against COVID-19.
【저자키워드】 COVID-19, SARS-CoV-2, Inflammation, Cytokines, Lymphocytes, macrophages, immunomodulation, quercetin, autophagy, polyphenols, 【초록키워드】 clinical trial, Pathogenesis, severe COVID-19, Vaccines, SARS-COV-2 infection, COVID-19 pandemic, severity, quercetin, in vitro, Health crisis, Spread, China, Health, COVID-19 pathogenesis, immune responses, Research, asymptomatic infection, death, Adaptive immune response, in vivo, polyphenol, mechanism, Immunomodulatory agents, immunomodulatory activity, broad spectrum, Inflammatory response, Analysis, immunological mechanism, Immunomodulatory agent, Chronic diseases, appearance, treat, dysregulated immune response, clinical disease, driving, identify, collected, develop, caused, approved, reducing, suggested, producing, dysregulated, elicited, therapeutic drug, 【제목키워드】 quercetin, response, Model, polyphenol, rescue, natural,