The Genus Luehea (Malvaceae-Tiliaceae): Review about Chemical and Pharmacological Aspects

Popularly known as "açoita-cavalo" (whips-horse), Luehea species (Malvaceae-Tilioideae) are native to America and are used in folk medicine as anti-inflammatory, antidiarrheal, antiseptic, expectorant, and depurative and against skin infections. Although there are studies showing the chemical constituents of some species, the active substances have not been properly identified. A systematic study was carried out through a computer search of data on CAPES journals, SciELO, ISI Bireme, PubMed, ScienceDirect, ScienceDomain Medline, and Google Scholar from published articles using key words: Luehea, açoita-cavalo, and Malvaceae. Luehea divaricata was the species with the highest number of studies observed. Triterpenes (9), flavonoids (6), and steroids (4), including saponins, organic acids (4), and one lignan, are the main types of secondary metabolites registered and the most cited flavonoids were rutin and quercetin and among triterpenes there was maslinic acid, which might be associated with the popular indication of its anti-inflammatory action. The vitexin, a C-glycosylated flavone, isolated from three different species, is cited as a possible taxonomic marker of the genus. Studies confirm in part the medicinal uses of plants named as "açoita-cavalo" species. Some pharmacological activities, not assigned to the species of the genus Luehea by populations, were observed in laboratory experiments.