Phytochemical and pharmacological properties of Xanthium species: a review

The genus Xanthium is an annual herb belonging to the family Compositae, widely distributed worldwide. The plants of Xanthium have long been used as traditional Chinese medicine for treating fever, rhinitis, headache, sinusitis, tympanitis, scrofula, and arthritis. The secondary metabolites of Xanthium species have been studied since the 1960s. So far, various chemical constituents have been isolated from the plants of Xanthium, including sesquiterpenoids, triterpenoids, diterpenoids, monoterpenoids, simple phenylpropanoids, lignans, coumarins, steroids, flavonoids, quinones, thiazinediones, thiophenes, glycosides, and others. Moreover, these compounds and extracts from Xanthium species have been reported to show various pharmacological activities, including anti-cancer, anti-inflammatory, anti-diabetic, anti-microbial, anti-oxidant, anti-malarial, and anti-trypanosomal activities. Clinical studies indicated that the plants of the Xanthium genus exhibited significant curative effects on anaphylactic rhinitis, asthma, arthritis, and infantile diarrhea. In addition, improper use could cause severe toxic reactions because of the poisonous components found in the whole plant of Xanthium. This review summarizes the botany, traditional uses, secondary metabolites, quality control, pharmacological activities, clinical studies, and toxicology of Xanthium species. This review also discusses the gaps that still exist in present studies on Xanthium species to provide a scientific reference for further studies and accelerate the contemporary development of Xanthium species.