Phytochemical Insights and Biological Potential of the Helianthus Genus

The Helianthus genus comprises more than 60 species distributed throughout North and Central America, with a few extending into South America. Among these, H. annuus and H. tuberosus represent the most widely utilized and extensively investigated species. The aim of this paper is to provide an overview of the current knowledge regarding the phytochemical composition and biological activities of Helianthus species. Phytochemical studies of Helianthus taxa have demonstrated that terpenoid constituents, including sesquiterpene lactones, diterpenes, and triterpenes, together with phenolic compounds, constitute the principal classes of secondary metabolites. Pharmacological investigations on Helianthus extracts have revealed a broad spectrum of biological activities. More than twenty distinct bioactivities have been reported for H. annuus, with the majority supported by in vitro assays (≈26 reports), reflecting multiple experimental evaluations per activity using different plant parts, extracts, and models; followed by a substantial number of in vivo studies in animal models (≈21 reports), and very limited clinical evidence. In comparison, five bioactivities have been described for H. tuberosus, mainly in vitro with a few in vivo reports, whereas only single in vitro bioactivities have been described for H. salicifolius and H. angustifolius. Among these, antidiabetic, antioxidant, antimicrobial, and anticancer properties are the most frequently documented.