Farfarae Flos: A review of botany, traditional uses, phytochemistry, pharmacology, and toxicology

Ethnopharmacological relevance: Farfarae Flos (FF; dried flower buds of Tussilago farfara L.), a widely used traditional Chinese medicine (TCM), is also known as "Kuandonghua" (Chinese: ). It has a wide range of pharmacological effects and has long been used to treat various respiratory conditions including cough, asthma, and acute or chronic bronchitis.

Aims: This study reviews the current advances in the research on the botany, ethnopharmacology, phytochemistry, pharmacology, and toxicology of Farfarae Flos. Prospects for future investigation and application of this herb are also discussed.

Materials and methods: Information on FF was collected from both published materials (such as ancient and modern books, Ph.D. and M. Sc. dissertations, monographs on medicinal plants, and pharmacopoeia) and electronic databases (such as CNKI, SciFinder, WanFang data, PubMed, ScienceDirect, Web of Science, Taylor&Francis, ACS Publications, Wiley, Springer, Europe PMC, EBSCOhost, J-STAGE, and Google Scholar).

Results: Approximately 175 chemical compounds, including terpenoids, organic acids, flavonoids, alkaloids, chromones, volatile oils, and other compounds, have been isolated from FF. This TCM has been reported to produce pharmacological effects on the respiratory, cardiovascular, and digestive systems, and exert antioxidant, anti-inflammatory, and neuroprotective activities. FF is safe in the traditional dose range, but the potential toxicity due to the emergence of pyrrolidine alkaloids needs to be paid more attention.

Conclusions: FF is a commonly used TCM with pharmacological activities mainly on the respiratory system. This study suggests that the further expansion of the pharmacological effect of FF and in-depth study of its prescription need to be concerned about. The investigations of the role of more active substances and the pharmacokinetics of the hepatotoxic components of FF will help to maximize the therapeutic potential and promote its popularization and application. Meanwhile, it is important to pay attention to pursue research on the similarities and differences between the leaves and the flower buds to find their respective advantages and make rational use of T. farfara L.

Keywords: Botany; Farfarae flos; Pharmacology; Phytochemistry; Toxicology; Traditional uses.