Anthelmintic Activity of Crude Extract and Essential Oil ofTanacetum vulgare(Asteraceae) against Adult Worms ofSchistosoma mansoni
Schistosomiasis, a parasitic disease caused by trematode flatworms of the genusSchistosoma, affects more than 200 million people worldwide, and its control is dependent on a single drug, praziquantel.Tanacetum vulgare(Asteraceae) is used in folk medicine as a vermifuge. This study aimed to investigate thein vitroschistosomicidal activity of the crude extract (TV) and the essential oil (TV-EO) from the aerial parts ofT. vulgare. TV-EO was obtained by hydrodistillation and analyzed by GC/MS, which allowed the identification ofβ-thujone (84.13%) as the major constituent. TV and TV-EO, at 200 μg/mL, decreased motor activity and caused 100% mortality of all adult worms. At 100 and 50 μg/mL, only TV caused death of all adult worms, while TV-EO was inactive. TV (200 μg/mL) was also able to reduce viability and decrease production of developed eggs. Confocal laser scanning microscopy showed morphological alterations in the tegument of theS. mansonisurface after incubation with TV (50 and 100 μg/mL). Quantitative analysis on the schistosomes tegument showed that TV caused changes in the numbers of tubercles ofS. mansonimale worms in a dose-dependent manner. The findings suggest thatT. vulgareis a potential source of schistosomicidal compounds.