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Objective: To compare the in vitro antiparasitic activity of aqueous extracts from Ziziphus joazeiro leaves and stem bark against Trypanosoma cruzi, Leishmania braziliensis, and Leishmania infantum, as well as to evaluate its cytotoxicity in mammalian cells, in addition to identifying the chemical composition of the extracts. Methods: Ziziphus joazeiro leaf and stem bark aqueous extracts were prepared by cold extraction maceration and subjected to ultra-efficient liquid chromatography coupled to a quadrupole/time of flight system. The susceptibility assays used Trypanosoma cruzi CL-B5 strains and promastigote forms of Leishmania braziliensis and Leishmania infantum for antiparasitic activity of the extracts. Moreover, mammalian fibroblasts NCTC clone 929 were used for cytotoxicity analysis. Results: Terpenoid compounds, flavonoids and phenolic acid were identified in extracts. The stem bark aqueous extracts presented more significant results in terms of antiparasitic activity compared with the leaf aqueous extracts, especially against Leishmania braziliensis and Leishmania infantum promastigote forms with an IC50 < 500 μg/mL. The cytotoxicity evaluation showed moderate toxicity of the stem bark aqueous extracts, which is relevant information for the rational use of this plant part since it is widely used by the population. Conclusions: These preliminary results may contribute to the formulation of new therapeutic agents against this group of neglected diseases, so further investigations are required to delineate the mechanisms of action mainly of the aqueous extract of stem bark of Ziziphus joazeiro.

(1) Background: Candida is a genus of yeasts with notable pathogenicity and significant ability to develop antimicrobial resistance. Gossypium hirsutum L., a medicinal plant that is traditionally used due to its antimicrobial properties, has demonstrated significant antifungal activity. Therefore, this study investigated the chemical composition and anti-Candida effects of aqueous (AELG) and hydroethanolic (HELG) extracts obtained from the leaves of this plant. (2) Methods: The extracts were chemically characterized by UPLC–QTOF-MS/MS, and their anti-Candida activities were investigated by analyzing cell viability, biofilm production, morphological transition, and enhancement of antifungal resistance. (3) Results: The UPLC–QTOF-MS/MS analysis revealed the presence of twenty-one compounds in both AELG and HELG, highlighting the predominance of flavonoids. The combination of the extracts with fluconazole significantly reduced its IC50 values against Candida albicans INCQS 40006, Candida tropicalis INCQS 40042, and C. tropicalis URM 4262 strains, indicating enhanced antifungal activity. About biofilm production, significant inhibition was observed only for the AELG-treated C. tropicalis URM 4262 strain in comparison with the untreated control. Accordingly, this extract showed more significant inhibitory effects on the morphological transition of the INCQS 40006 and URM 4387 strains of C. albicans (4) Conclusions: Gossypium hirsutum L. presents promising antifungal effects, that may be potentially linked to the combined activity of chemical constituents identified in its extracts.

Nas últimas décadas, a resistência bacteriana frente aos antimicrobianos se constituiu em um sério problema para a saúde pública, impondo barreiras ao controle de diversas espécies de microrganismos. O carvacrol é um composto fenólico geralmenete encontrado como componente majoritário do óleo essencial de algumas plantas como Origanum vulgare (orégano), Lippia graveolens (Lípia) e Lipia sidoides (alecrim-pimenta). Estudos demonstram a atividade antibacteriana do orégano, possivelmente devido ao carvacrol. Para avaliar a ação antimicrobiana desse composto, foram utilizadas linhagens padrão bacterianas (Staphylococcus aureus ATCC25923 e Pseudomonasa aeruginosa ATCC15442) e fúngicas (Candida albicans ICB12, C. krusei ATCC6258 e C. tropicalis ATCC13803). Os métodos de microdiluição em caldo e de contato gasoso foram utilizados para determinar a concentração inibitória mínima (CIM) e a dose inibitória mínima (DIM) respectivamente, bem como a atividade moduladora da ação antibiótica através de ambos os métodos. O carvacrol, combinado em concentrações subinibitórias com as drogas antimicrobianas apresentou resultados relevantes frente às cepas de Staphylococcus aureus e Candida albicans, por tanto este estudo permitiu comprovar a atividade moduladora do carvacrol.