BIOPROSPECÇÃO DAS FOLHAS DE Fridericia platyphylla (Cham.) L.G. Lohmann E SELEÇÃO DE SEUS ATIVOS COM ATIVIDADE LEISHMANICIDA IN VITRO

Abstract

The therapeutics currently used for the treatment of Cutaneous Leishmaniasis present significant limitations, such as high toxicity, difficulties in administration, high costs, and parasite resistance. In this context, natural products represent promising alternatives, as they are sources of bioactive compounds with leishmanicidal potential. Fridericia platyphylla (Cham.) L.G. Lohmann, traditionally employed for the treatment of kidney stones and joint pain, has also demonstrated activity against Leishmania. The present study aimed to evaluate the effects of the standardized extract and leaf fractions of F. platyphylla against promastigote and amastigote forms of Leishmania amazonensis in vitro, as well as to develop and characterize hydroxypropylmethylcellulose (HPMC)- based films incorporated with these compounds. Phytochemical analysis revealed the abundant presence of the flavonoids rutin, taxifolin, and eriodictyol. The crude extract (AB) and its fractions (aqueous – AQ, dichloromethane – DCM, and hexane – HEX) showed no significant cytotoxicity in sheep erythrocytes or RAW 264.7 cells. In assays against L. amazonensis promastigotes, the HEX fraction exhibited the strongest activity (IC50 = 17.23 µg/mL; SI = 132.2), followed by the DCM fraction (IC50 = 37.7 µg/mL; SI = 75.43) and the crude extract (IC50 = 144 µg/mL; SI = 19.76). HPMC films incorporated with AB, DCM, and HEX were homogeneous, flexible, and stable, with compound–polymer interactions confirmed by infrared spectroscopy and X-ray diffraction. The films showed cytotoxicity greater than 60% against promastigotes, with the HPMC–HEX formulation standing out by also showing better effects against axenic amastigotes, in addition to reducing macrophage infection rates. Although leishmanicidal activity was reduced after incorporation, possibly due to the controlled release of the compounds, the formulations demonstrated potential as complementary therapeutic strategies, which may improve adherence to the treatment of Cutaneous Leishmaniasis.