ABSTRACT
Today, broad research on natural flavonoids has highlighted new promising approaches for biomedical applications. Among many flavonoids, quercetin (3,3′,4′,5,7-pentahydroxyflavone) is one of the most promising bioflavonoids derived from many phytomedicinal compounds with surprising pharmacological properties including cell-cycle regulation, apoptosis actuation, angiogenesis restraint limits and antiulcer, anticancer, antibacterial, anti-inflammatory, antiallergy, antioxidant, antidiabetic and antiviral properties. Quercetin has a theoretical but noteworthy ability to inhibit SARS-CoV-2 replication, which may be possible to apply treatment of COVID-19. The quercetin derivatives easily digest in the human body through methylation, sulphation or glucuronidation via mouth, liver, small intestine and kidneys. Many factors such as pH, heat and metal ions can possibly induce the oxidation and degradation of quercetin during food processing and storage. In particular, the principal molecular and cellular mechanisms of quercetin to various biomedical applications are discussed in detail.
