Eduardo Caio Torres-Santos

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2',6'-Dihydroxy-4'-methoxychalcone (DMC) was purified from the dichloromethane extract of Piper aduncum inflorescences. DMC showed significant activity in vitro against promastigotes and intracellular amastigotes of Leishmania amazonensis, with 50% effective doses of 0.5 and 24 micrograms/ml, respectively. Its inhibitory effect on amastigotes is apparently(More)
OBJECTIVES The pterocarpanquinone LQB-118, previously demonstrated to be effective in vivo via oral delivery, was investigated for its mechanism in selective parasite killing. METHODS Oxidative stress in Leishmania amazonensis was analysed by evaluating reactive oxygen species (ROS) production (2',7'-dichlorodihydrofluorescein diacetate) and the loss of(More)
The purinergic P2X(7) receptor is a membrane protein of leucocytes involved in the clearance of intracellular bacteria such as Chlamydia and Mycobacterium. In this work, we investigated the role and modulation of macrophage P2X(7)R in intracellular infection with the protozoan parasite Leishmania amazonensis. Upon infection, isolated murine macrophages(More)
Leishmania parasites, despite being able to synthesize their own sterols, acquire and accumulate significant amounts of cholesterol through low density lipoprotein (LDL) particle endocytosis. The role of this system in Leishmania amazonensis promastigotes under pharmacological pressure by sterol biosynthesis inhibitors (SBIs) was investigated. First, thin(More)
OBJECTIVES The effects of the antileishmanial chalcone 2',6'-dihydroxy-4'-methoxychalcone (DMC) on Leishmania amazonensis sterol composition and biosynthesis were investigated to obtain information about the mechanism of growth inhibition by DMC on this parasite. METHODS The interference of sterol biosynthesis by DMC was studied in drug-treated(More)
As pterocarpanquinonas 8a-c, previamente sintetizadas em nosso laboratório, e uma série homóloga de derivados, substâncias 9a-c preparadas neste trabalho, foram avaliadas em células de câncer de mama (MCF-7) e em cultura dos parasitas Leishmania amazonensis e Plasmodium falciparum. As substâncias 8a-c foram mais potentes que 9a-c nas células tumorais e em(More)
Leishmania amazonensis lacks a de novo mechanism for cholesterol synthesis and therefore must scavenge this lipid from the host environment. In this study we show that the L. amazonensis takes up and metabolizes human LDL(1) particles in both a time and dose-dependent manner. This mechanism implies the presence of a true LDL receptor because the uptake is(More)
Essential oils from fresh Piperaceae leaves were obtained by hydrodistillation and analyzed by gas chromatography mass spectrometry (GC-MS), and a total of 68 components were identified. Principal components analysis results showed a chemical variability between species, with sesquiterpene compounds predominating in the majority of species analyzed. The(More)
Piper amalago L. leaves were extracted with supercritical carbon dioxide and compressed propane under different conditions, and with chloroform by the conventional maceration method. These methods were compared for the pyrrolidine alkaloid content. Supercritical carbon dioxide (SFE-CO₂) at 313 K and 12.55 MPa showed the highest selectivity for the main(More)
Pterocarpanquinones (1a-e) and the aza-pterocarpanquinone (2) were synthesized through palladium catalyzed oxyarylation and azaarylation of conjugate olefins, and showed antineoplasic effect on leukemic cell lines (K562 and HL-60) as well as colon cancer (HCT-8), gliobastoma (SF-295) and melanoma (MDA-MB435) cell lines. Some derivatives were prepared (3-8)(More)