Strychnos pseudoquinaand Its Purified Compounds Present an EffectiveIn VitroAntileishmanial Activity

Abstract

The development of new and cost-effective alternative therapeutic strategies to treat leishmaniasis has become a high priority. In the present study, the antileishmanial activity ofStrychnos pseudoquinaSt. Hil. was investigated and pure compounds that presented this biological effect were isolated. An ethyl acetate extract was prepared, and it proved to be effective againstLeishmania amazonensis. A bioactivity-guided fractionation was performed, and two flavonoids were identified, quercetin 3-O-methyl ether and strychnobiflavone, which presented an effective antileishmanial activity againstL. amazonensis, and studies were extended to establish their minimum inhibitory concentrations (IC₅₀), their leishmanicidal effects on the intra-macrophageLeishmaniastage, as well as their cytotoxic effects on murine macrophages (CC₅₀), and in O₊human red blood cells. The data presented in this study showed the potential of an ethyl acetate extract ofS. pseudoquina, as well as two flavonoids purified from it, which can be used as a therapeutic alternative on its own, or in association with other drugs, to treat disease evoked byL. amazonensis.