Flavonoids and Sesquiterpene Lactones from <i>Artemisia absinthium</i> and <i>Tanacetum parthenium</i> against <i>Schistosoma mansoni</i> Worms

Abstract

Human schistosomiasis, caused by trematode worms of the genus <i>Schistosoma</i>, is one of the most significant neglected tropical diseases, affecting more than 200 million individuals worldwide and praziquantel is the only available drug to treat this disease. <i>Artemisia absinthium</i> L. and <i>Tanacetum parthenium</i> L. are species popularly used as anthelmintics. We investigated the <i>in vitro</i> schistosomicidal activity of crude extracts of <i>A. absinthium</i> (AA) and <i>T. parthenium</i> (TP) and their isolated compounds. AA and TP, at 200 <i>μ</i>g/mL, were active, causing 100% mortality of all adult worms. Chromatographic fractionation of AA leads to isolation of artemetin and hydroxypelenolide, while santin, apigenin, and parthenolide were isolated from TP. Artemetin, hydroxypelenolide, santin, and apigenin, at 100 <i>μ</i>M, were inactive against adult worms. Parthenolide (12.5 to 100 <i>μ</i>M) caused 100% mortality, tegumental alterations, and reduction of motor activity of all adult worms of <i>S. mansoni</i>, without affecting mammalian cells. Confocal laser scanning microscopy showed tegumental morphological alterations and changes on the numbers of tubercles of <i>S. mansoni</i> worms. This report provides the first evidence for the <i>in vitro</i> activity of parthenolide against adult worms of <i>S. mansoni</i>, opening the route to further schistosomicidal studies with this compound.