Quercetin and Vitamin C: An Experimental, Synergistic Therapy for the Prevention and Treatment of SARS-CoV-2 Related Disease (COVID-19) https://www.frontiersin.org/articles/10.3389/fimmu.2020.01451/full A very long article, see the link for a lot more detail. [Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) represents an emergent global threat which is straining worldwide healthcare capacity. As of May 27th, the disease caused by SARS-CoV-2 (COVID-19) has resulted in more than 340,000 deaths worldwide, with 100,000 deaths in the US alone. It is imperative to study and develop pharmacological treatments suitable for the prevention and treatment of COVID-19. Ascorbic acid is a crucial vitamin necessary for the correct functioning of the immune system. It plays a role in stress response and has shown promising results when administered to the critically ill. Quercetin is a well-known flavonoid whose antiviral properties have been investigated in numerous studies.] [DiscussionA multi-drug approach with quercetin and vitamin C may disrupt virus entry, replication, enzyme activity and assembly, and concurrently fortify the immune response promoting early IFNs production, modulating interleukins, promoting T cell maturation, and phagocytic activity. Quercetin and ascorbic acid co-administration represents an experimental strategy for prophylaxis and treatment of several respiratory viruses, such as SARS-CoV-2. The blockage of virus entry represents a key strategy and quercetin impedes viral membrane fusion for both influenza and SARS-Cov in vitro (98). Quercetin also targets viral polymerases and may disrupt replication via the inhibition of reverse transcriptase enzymes. Quercetin further inhibits SARS 3CL protease by binding to its GLN189 site (102), which is expressed similarly by SARS-COV-2 (105) and provides a direct mechanistic rationale for its experimental clinical use—in addition to its immunoenhancing and anti-inflammatory actions. Despite the limitations of in vitro research, it is noteworthy that the few in vivo models reviewed here indicate increased survival from lethal viral infection when treated with quercetin (42,]
