Isatis indigotica: a review of phytochemistry, pharmacological activities and clinical applications

Isatis indigotica Fort. (I. indigotica) is an herbaceous plant belonging to Cruciferae family. Its leaf (IIL) and root (IIR) are commonly used in traditional Chinese medicines (TCMs) with good clinical efficacies such as clearing away heat and detoxification, cooling blood and reducing swelling. This review aimed to provide a systematic summary on the phytochemistry, pharmacology and clinical applications of I. indigotica.This plant contains alkaloids, organic acids, flavonoids, lignans, nucleosides, amino acids, and steroids. Previous pharmacological researches indicated that I. indigotica possesses promising antivirus, antibacterial, immunoregulatory, anti-inflammation, and cholagogic effects. Importantly, it can inhibit various viruses, such as influenza, hepatitis B, mumps, herpes simplex, cytomegalovirus, and coxsachievirus. Clinically, it is frequently used to treat various viral diseases like viral influenza, parotitis and viral hepatitis. Consequently, I. indigotica may be beneficial for the prevention and treatment of coronavirus disease 2019 (COVID-19).This paper reviewed the chemical constituents, pharmacological effects and clinical applications of I. indigotica which may guide further research and application of this plant.