The Genus Ageratina (Asteraceae) in America: An Insight into its Chemistry and Pharmacological Potential

Background: Ageratina is an American genus of the tribe Eupatorieae (Asteraceae), comprising about 320 species. In Mexico, some species of this genus are highly valued for their medicinal properties, particularly A. pichinchensis, A. petiolaris, and A. grandifolia. Furthermore, herbal preparations of A. pichinchensis are available for treating several mycoses. Aims and Objective: The present review is aimed to summarize the chemical and pharmacological properties of 37 species of the Ageratina genus up to April, 2022. Methods: Data were recorded using online scientific databases, including Scopus, PubMed, Google Scholar, Taylor and Francis Imprints, National Center for Biotechnology Information, Science Direct, JSTOR, and SciFinder. The information was gathered from research articles, relevant books on herbal medicinal plants and the history of medicinal plants from Mexico, theses, reports, and web pages. Results: The specialized metabolites present in the Ageratina genus belong to different chemical classes, including flavonoids, benzyl benzoates, benzofurans, chromenes, and terpenoids. The chromenes, benzofurans, and benzyl benzoates are the metabolites most widespread in the genus. So far, the species more thoroughly investigated is A. adenophora. Ageratina has received little attention from the pharmacological point of view. The studies are limited to 10 species. Biological studies have been conducted on extracts and/or compounds isolated from plants collected mainly from China and Mexico. The results revealed that the extracts and metabolites possess several biological activities, including antiviral, antioxidant, antimicrobial, anti-inflammatory, antinociceptive, antifeedant, larvicidal, acaricidal, antidiabetic, antiprotozoal, and wound-healing properties. In the case of A. pichinchensis, A. petiolaris, and A. grandifolia, the pharmacological studies provided evidence for their use for treating gastrointestinal complaints and diabetes. Furthermore, herbal preparations of A. pichinchensis are now widely used for alleviating onychomycosis. A. adenophora, is the most investigated species, chemically and biologically; however, some hepatotoxicity effect has been recorded. Conclusion: This review recapitulates information on the Ageratina genus, highlighting the phytochemistry and biological activities of the species investigated. It is important to point out that the pharmacological potential of this large genus remains largely unexplored.