Avaliação esquistossomicida de extratos e substâncias de Renealmia petasites Gagnep (Zingiberaceae) E Vernonia polyanthes (Asteraceae)

Abstract

Schistosomiasis is a neglected tropical disease (NTD) caused by the parasite of the genus Schistosoma, particularly S. mansoni. Currently, praziquantel (PZQ) is the only pharmacological tool for disease control. However, its scope is limited in relation to the biological cycle forms of the parasite, and there are reports of resistance to the use of this drug. In this sense, traditional medicine can become an important ally in the search for new substances or extracts with schistosomicidal activity. In this context, the species Renealmia petasites Ganep stands out, where rhizomes are used by the population for antiparasitic, analgesic purposes, and for the treatment of intestinal disorders, as well as the species Vernonia polyanthes, which has ethnobotanical indications as an expectorant and for the treatment of inflammatory and parasitic diseases. Considering the popular use of both species, the objectives of this study were to evaluate the schistosomicidal activity of the hydroalcoholic extract of R. petasites rhizomes and the dichloromethane leaf extract of V. polyanthes, as well as isolated substances from these extracts. According to the results, two semipurified substances were obtained from R. petasites, which have not been identified yet. Furthermore, the extract from fresh rhizomes of R. petasites showed in vitro schistosomicidal activity at concentrations of 100 μg/mL and 200 μg/mL, but in in vivo assays at a dose of 400 mg/kg, this extract was not able to reduce the number of worms or eggs in animals infected with S. mansoni. From the leaf extract of V. polyanthes, the sesquiterpene lactone Glaucolide A, coded as GLDA, was isolated. In in vitro assays, both the extract of V. polyanthes and Glaucolide A (GLDA) at concentrations of 12.5 μg/mL were able to cause the death of adult male and female S. mansoni worms. Finally, this study contributed to supporting the antiparasitic medicinal use of the species studied, revealing GLDA as a promising compound to be explored in future schistosomicidal studies.