RESUMO
5'-4-Alkyl/aryl-1H-1,2,3-triazole derivatives PILAB 1-12 were synthesized and a pharmacological screening of these derivatives was performed to identify a possible effect on the Central Nervous System (CNS) and to explore the associated mechanisms of action. The mice received a peritoneal injection (100 µmol/kg) of each of the 12 PILAB derivatives 10 min prior to the injection of pentobarbital and the mean hypnosis times were recorded. The mean hypnosis time increased for the mice treated with PILAB 8, which was prevented when mice were administered CTOP, a µ-opioid antagonist. Locomotor and motor activities were not affected by PILAB 8. The anxiolytic effect of PILAB 8 was evaluated next in an elevated-plus maze apparatus. PILAB 8 and midazolam increased a percentage of entries and spent time in the open arms of the apparatus compared with the control group. Conversely, a decrease in the percentages of entries and time spent in the closed arms were observed. Pretreatment with naloxone, a non-specific opioid antagonist, prior to administration of PILAB 8 exhibited a reverted anxiolytic effect. PILAB 8 exhibited antinociceptive activity in the hot plate test, and reduced reactivity to formalin in the neurogenic and the inflammatory phases. These data suggest that PILAB 8 can activate µ-opioid receptors to provoke antinociceptive and anti-inflammatory effects in mice.
Assuntos
Ansiolíticos/uso terapêutico , Analgésicos/uso terapêutico , Animais , Anti-Inflamatórios/uso terapêutico , Ansiedade/tratamento farmacológico , Ansiedade/metabolismo , Hipnóticos e Sedativos/uso terapêutico , Masculino , Camundongos , Morfina/uso terapêutico , Naloxona/uso terapêutico , Antagonistas de Entorpecentes/uso terapêutico , Dor/tratamento farmacológico , Dor/metabolismo , Medição da Dor , Receptores Opioides/metabolismoRESUMO
Extracts of Serjania lethalis A. St.-Hil leaves and stems were tested in order to identify potential agents against Leishmania amazonensis. The hexane fraction (HF) and dichloromethane subfractions (DDF and MDF) showed leishmanicidal effect. The anti-promastigote IC50 values were 10.29 (HF), 11.41 (DDF) and 28.33µg/mL (MDF); whereas those against amastigote were 7.2 (HF), 8.1 (DDF) and 6.5µg/mL (MDF). Among the fractions and subfractions assayed, only HF altered the cell cycle of the parasite, increasing 3-fold the number of cells in the sub-G0/G1 phase. HF also changed the parasite mitochondrial membrane potential (ΔΨm) and the percentage of annexin-V-propidium iodide positive promastigotes. Our evaluations of the IC50 values showed that HF, DDF and MDF decreased NO production in infected macrophages stimulated with IFN-γ and LPS. Moreover, HF increased the production of TNF-α in Leishmania infected macrophages. This paper reports for the first time the leishmanicidal activity of extracts and fractions of Serjania lethalis leaves and also characterizes its leishmanicidal and immunomodulatory properties.
Assuntos
Antiprotozoários/farmacologia , Leishmania mexicana/efeitos dos fármacos , Macrófagos Peritoneais/efeitos dos fármacos , Magnoliopsida/química , Extratos Vegetais/farmacologia , Animais , Anexina A5/análise , Fase G1/efeitos dos fármacos , Hexanos/química , Imunomodulação , Concentração Inibidora 50 , Interferon gama/imunologia , Leishmania mexicana/crescimento & desenvolvimento , Leishmania mexicana/fisiologia , Lipopolissacarídeos/imunologia , Macrófagos Peritoneais/imunologia , Macrófagos Peritoneais/parasitologia , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Cloreto de Metileno/química , Camundongos , Óxido Nítrico/biossíntese , Extratos Vegetais/química , Folhas de Planta/química , Fase de Repouso do Ciclo Celular/efeitos dos fármacos , Fator de Necrose Tumoral alfa/biossínteseRESUMO
RATIONALE: The study of natural products by electrospray ionization tandem mass spectrometry (ESI-MS/MS) is an important strategy for the characterization of the major fragmentation reactions which can then help to determine the composition of complex mixtures. Application of ESI-MS/MS to a series of isopimarane diterpenes from Velloziaceae allowed the rationalization of their fragmentation mechanisms. METHODS: Velloziaceae diterpenes were isolated by silica gel column chromatography and investigated by ESI-MS/MS analysis. The fragmentation studies were performed on a quadrupole-time-of-flight instrument using N2 as the collision gas. To help rationalize the fragmentation pathways observed, the geometry and sites of reactivity of the diterpenes were obtained by theoretical calculations using the B3LYP/6-31 + G(d,p) model. Fragmentation mechanisms were proposed on the basis of the calculated protonation sites and product ions energies using density functional theory (DFT) methods. RESULTS: The presence of hydroxyl and carbonyl groups on the terpene core influences the protonation site observed. One compound showed a radical cation as the base peak. MS/MS spectra exhibit water elimination as the major fragmentation pathway (via two ways), either when protonation takes place on the oxygen atom, or through elimination after activation from hydrogen migration. After the elimination of water, the formation of an endocyclic double bond induces a sequential retro-Diels-Alder (RDA) reaction as the major fragmentation step. CONCLUSIONS: A thorough rational analysis of the fragmentation mechanisms of protonated Velloziaceae diterpenes was used to propose the dissociation mechanisms in ESI-MS/MS. The presence of esters in the side chain also influenced the intensity or occurrence of the observed protonated or cationized molecules in ESI-MS. These results will aid the identification of analogues in sample extracts in future metabolomics studies.
Assuntos
Abietanos/análise , Abietanos/química , Magnoliopsida/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem/métodos , Modelos MolecularesRESUMO
Polyamine-naphthoquinone conjugates 5a-c were synthesized by nucleophilic displacement of 2-methoxy-lawsone 3a, 2-methoxylapachol 3b and 2-methoxy-nor-lapachol 3c with the polyamine N1-Boc-N5-Bn-spermidine 4. Unprotected derivatives 6a-c were synthesized to evaluate the effect of the protective Boc group on the activity of compounds 5a-c. The colorimetric MTT assay was used to evaluate their cytotoxic activity. All compounds were active against human lines of promyelocytic leukemia (HL-60), lung cancer (GLC4), Burkitt lymphoma (Daudi) and a mouse breast tumor (Ehrlich carcinoma), but only unprotected 6a-c showed activity against the human line of melanoma (MV-3). IC50 values were obtained from dose response curves by linear regression. DNA fragmentation was measured by quantification of the subG1 peak of the cell cycle. Apoptosis of HL-60 treated with 5c was dose-dependent. The amount of DNA fragmentation observed by exposure of HL-60 to 25 microM of compounds 5a-c and 6a-c is compatible with the decrease in viability induced by the drugs at this concentration. Production of ROS was measured by H2-CFDA. Kinetics of HL-60 DNA fragmentation and ROS formation by 5c indicated that production of ROS precedes cell death. In conclusion, spermidine-1,4-naphthoquinone conjugates exhibited an increase in activity compared with the natural products and induced apoptosis of tumor cell lines by a mechanism that is mediated, at least in part, by ROS production.