Introduction
Scientific research continues on new preventive and therapeutic strategies against severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2). So far, there is no proven curative treatment for the Novel Coronavirus Disease 2019 (COVID-19), and while an effective vaccine is expected, ”wild” protocols based on ”ancient” anti-inflammatory and anti-viral drugs are being offered. A valid and alternative therapeutic approach needs to be developed.
Affecting the nasopharyngeal cells first, SARS-CoV-2 can target different tissues such as lung, vascular endothelium, kidney and nervous at various degrees and it can cause severe illness and death.[1,2] With the advantage of the lack of systemic toxicity, flavonoids, including quercetin, are proven to potentialise routine drugs against Coronavirus.[3] Flavonoids owe their antioxidant, anti-inflammatory and anti-viral properties, against a wide range of DNA and RNA viruses, to their pleiotropic molecular structure that acts by targeting variable cells on multiple pathways.[4,5] Therefore, this study aimed to determine if quercetin had a curative role in the treatment of COVID-19.