RESUMEN

The development of coordination compounds with antineoplastic therapeutic properties is currently focused on non-covalent interactions with deoxyribonucleic acid (DNA). Additionally, the interaction profiles of these compounds with globular plasma proteins, particularly serum albumin, warrant thorough evaluation. In this study, we report on the interactions between biomolecules and complexes featuring hydrazone-type imine ligands coordinated with vanadium. The potential to enhance the therapeutic efficiency of these compounds through mitochondrial targeting is explored. This targeting is facilitated by the derivatization of ligands with triphenylphosphonium groups. Thus, this work presents the synthesis, characterization, interactions, and cytotoxicity of dioxidovanadium(V) complexes (C1-C5) with a triphenylphosphonium moiety. These VV-species are coordinated to hydrazone-type iminic ligands derived from (3-formyl-4-hydroxybenzyl)triphenylphosphonium chloride ([AH]Cl) and aromatic hydrazides ([H2L1]Cl-[H2L5]Cl). The structures of the five complexes were elucidated through single-crystal X-ray diffraction and vibrational spectroscopies, confirming the presence of dioxidovanadium(V) species in various geometries with degrees of distortion (τ = 0.03-0.50) and highlighting their zwitterionic characteristics. The molecular structural stability of C1-C5 in solution was ascertained using 1H, 19F, 31P, and 51V-nuclear magnetic resonance. Moreover, their interactions with biomolecules were evaluated using diverse spectroscopic methodologies and molecular docking, indicating moderate interactions (Kb ≈ 104 M-1) with calf thymus DNA in the minor groove and with human serum albumin, predominantly in the superficial IB subdomain. Lastly, the cytotoxic potentials of these complexes were assessed in keratinocytes of the HaCaT lineage, revealing that C1-C5 induce a reduction in metabolic activity and cell viability through apoptotic pathways.

Asunto(s)

Antineoplásicos , Complejos de Coordinación , ADN , Compuestos Organofosforados , Vanadio , Humanos , Vanadio/química , Vanadio/farmacología , Complejos de Coordinación/farmacología , Complejos de Coordinación/química , Complejos de Coordinación/síntesis química , Antineoplásicos/farmacología , Antineoplásicos/química , Antineoplásicos/síntesis química , Compuestos Organofosforados/química , Compuestos Organofosforados/farmacología , ADN/metabolismo , ADN/química , Supervivencia Celular/efectos de los fármacos , Hidrazinas/química , Hidrazinas/farmacología , Animales , Simulación del Acoplamiento Molecular , Albúmina Sérica Humana/química , Albúmina Sérica Humana/metabolismo , Estructura Molecular , Ligandos , Línea Celular Tumoral , Ensayos de Selección de Medicamentos Antitumorales

RESUMEN

Platelets are the critical target for preventing and treating pathological thrombus formation. However, despite current antiplatelet therapy, cardiovascular mortality remains high, and cardiovascular events continue in prescribed patients. In this study, first results were obtained with ortho-carbonyl hydroquinones as antiplatelet agents; we found that linking triphenylphosphonium cation to a bicyclic ortho-carbonyl hydroquinone moiety by a short alkyl chain significantly improved their antiplatelet effect by affecting the mitochondrial functioning. The mechanism of action involves uncoupling OXPHOS, which leads to an increase in mitochondrial ROS production and a decrease in the mitochondrial membrane potential and OCR. This alteration disrupts the energy production by mitochondrial function necessary for the platelet activation process. These effects are responsive to the complete structure of the compounds and not to isolated parts of the compounds tested. The results obtained in this research can be used as the basis for developing new antiplatelet agents that target mitochondria.

Asunto(s)

Plaquetas , Hidroquinonas , Potencial de la Membrana Mitocondrial , Compuestos Organofosforados , Inhibidores de Agregación Plaquetaria , Humanos , Plaquetas/metabolismo , Plaquetas/efectos de los fármacos , Hidroquinonas/farmacología , Hidroquinonas/química , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Mitocondrias/metabolismo , Mitocondrias/efectos de los fármacos , Compuestos Organofosforados/farmacología , Compuestos Organofosforados/química , Fosforilación Oxidativa/efectos de los fármacos , Activación Plaquetaria/efectos de los fármacos , Agregación Plaquetaria/efectos de los fármacos , Inhibidores de Agregación Plaquetaria/farmacología , Inhibidores de Agregación Plaquetaria/química , Especies Reactivas de Oxígeno/metabolismo

RESUMEN

INTRODUCTION: The use of triphenylphosphonium cation (TPP+) linked to phenolic compounds by alkyl chains has a significant relevance as a mitochondrial delivery strategy in biomedicine because it affects mitochondrial bioenergetics in models of noncommunicable diseases such as cancer and cardiovascular-related conditions. Studies indicate that a long alkyl chain (10-12 carbon) increases the mitochondrial accumulation of TPP+-linked drugs. In contrast, other studies show that these compounds are consistently toxic to micromolar concentrations (as observed in platelets). In the present study, we evaluated the in vitro effect of three series of triphenylphosphonium-linked acyl hydroquinones derivates on the metabolism and function of human platelets using 3-9 carbons for the alkyl linker. Those were assessed to determine the role of the length of the alkyl chain linker on platelet toxicity. METHODS: Human platelets were exposed in vitro to different concentrations (2-40 µM) of every compound; cellular viability, phosphatidylserine exposition, mitochondrial membrane potential (ΔΨm), intracellular calcium release, and intracellular ROS generation were assessed by flow cytometry. An in silico energetic profile was generated with Umbrella sampling molecular dynamics (MD). RESULTS AND CONCLUSIONS: There was an increase in cytotoxic activity directly related to the length of the acyl chain and lipophilicity, as seen by three techniques, and this was consistent with a decrease in ΔΨm. The in silico energetic profiles point out that the permeability of the mitochondrial membrane may be involved in the cytotoxicity of phosphonium salts. This information may be relevant for the design of new TPP+ -based drugs with a safe cardiovascular profile.

Asunto(s)

Antineoplásicos , Hidroquinonas , Humanos , Hidroquinonas/farmacología , Mitocondrias/metabolismo , Membranas Mitocondriales/metabolismo , Antineoplásicos/farmacología , Metabolismo Energético , Compuestos Organofosforados/farmacología , Compuestos Organofosforados/metabolismo , Potencial de la Membrana Mitocondrial

RESUMEN

Transcriptional analysis of the network of transcription regulators and target pathways in exposed organisms may be a hard task when their genome remains unknown. The development of hundreds of qPCR assays, including primer design and normalization of the results with the appropriate housekeeping genes, seems an unreachable task. Alternatively, we took advantage of a whole transcriptome study on Rhinella arenarum larvae exposed to the organophosphorus pesticides azinphos-methyl and chlorpyrifos to evaluate the transcriptional effects on a priori selected groups of genes. This approach allowed us to evaluate the effects on hypothesis-selected pathways such as target esterases, detoxifying enzymes, polyamine metabolism and signaling, and regulatory pathways modulating them. We could then compare the responses at the transcriptional level with previously described effects at the enzymatic or metabolic levels to obtain global insight into toxicity-response mechanisms. The effects of both pesticides on the transcript levels of these pathways could be considered moderate, while chlorpyrifos-induced responses were more potent and earlier than those elicited by azinphos-methyl. Finally, we inferred a prevailing downregulation effect of pesticides on signaling pathways and transcription factor transcripts encoding products that modulate/control the polyamine and antioxidant response pathways. We also tested and selected potential housekeeping genes based on those reported for other species. These results allow us to conduct future confirmatory studies on pesticide modulation of gene expression in toad larvae.

Asunto(s)

Cloropirifos , Plaguicidas , Animales , Azinfosmetilo , Cloropirifos/metabolismo , Plaguicidas/farmacología , Larva , Transcriptoma , Compuestos Organofosforados/farmacología , Antioxidantes/metabolismo , Bufo arenarum/metabolismo , Esterasas/metabolismo , Poliaminas/metabolismo , Factores de Transcripción/metabolismo

RESUMEN

Diazinon is an organophosphorus pesticide, which may have potential toxic effects on the liver and immune system; however, the underlying mechanisms remain mostly unidentified. This work is aimed at evaluating the oxidative stress and cell cycle alterations elicited by low-dose diazinon in a rat liver cell line (BRL-3A) and spleen mononuclear cells (SMC) from Wistar rats. Diazinon (10-50 µM) caused early reactive oxygen species (ROS) generation (from 4 h) as well as increased O2•- level (from 0.5 h), which led to subsequent lipid peroxidation at 24 h, in BRL-3A cells. In SMC, diazinon (20 µM) produced similar increases in ROS levels, at 4 and 24 h, with the highest O2•- level being found at 4 h. Low-dose diazinon induced G1-phase arrest and cell death in hepatic cells and SMC. Therefore, diazinon could affect the liver and the immunological system through the premature oxidative stress induction.Abbreviations: O2•-: superoxide anion radical; ROS: reactive oxygen species; SMC: spleen mononuclear cells; TBARS: thiobarbituric acid reactive substances.

Asunto(s)

Diazinón , Plaguicidas , Animales , Diazinón/metabolismo , Diazinón/toxicidad , Hígado , Compuestos Organofosforados/metabolismo , Compuestos Organofosforados/farmacología , Estrés Oxidativo , Ratas , Ratas Wistar , Especies Reactivas de Oxígeno/metabolismo , Bazo/metabolismo , Superóxidos/metabolismo , Superóxidos/farmacología , Sustancias Reactivas al Ácido Tiobarbitúrico/metabolismo , Sustancias Reactivas al Ácido Tiobarbitúrico/farmacología

RESUMEN

Amides derived from ferulic acid have a wide spectrum of pharmacological activities, including antitumor and antifungal activity. In the present study, a series of ten amides were obtained by coupling reactions using the reagents (benzotriazol-1-yloxy) tripyrrolidinophosphonium hexafluorophosphate (PyBOP) and N,N'-dicyclohexylcarbodiimide (DCC). All the compounds were identified on the basis of their IR, 1H- and 13C-NMR, HRMS data, and with yields ranging from 43.17% to 91.37%. The compounds were subjected to cytotoxic tests by the alamar blue technique and antifungal screening by the broth microdilution method to determine the minimum inhibitory concentration (MIC). The amides 10 and 11 displayed the best result in both biological evaluations, and compound 10 was the most potent and selective in HL-60 cancer cells, with no cytotoxicity on healthy cells. This amide had antifungal activity in all strains and had the lowest MIC against Candida albicans and Candida tropicalis. The possible mechanism of antifungal action occurs via the fungal cell wall. Molecular modeling suggested that compounds 10 and 11 interact with the enzymes GWT1 and GSC1, which are essential for the development of C. albicans. The findings of the present study demonstrated that compounds 10 and 11 may be used as a platform in drug development in the future.

Asunto(s)

Ácidos Cumáricos/farmacología , Diciclohexilcarbodiimida/química , Compuestos Organofosforados/química , Triazoles/química , Amidas/química , Amidas/farmacología , Antifúngicos/farmacología , Candida/efectos de los fármacos , Ácidos Cumáricos/química , Diciclohexilcarbodiimida/farmacología , Concentración 50 Inhibidora , Pruebas de Sensibilidad Microbiana , Simulación del Acoplamiento Molecular , Aceites Volátiles/química , Compuestos Organofosforados/farmacología , Triazoles/farmacología

RESUMEN

Platelet activation plays a key role in cardiovascular diseases. The generation of mitochondrial reactive oxygen species (ROS) has been described as a critical step required for platelet activation. For this reason, it is necessary to find new molecules with antiplatelet activity and identify their mechanisms of action. Mitoquinone (MitoQ) is a mitochondria-targeted antioxidant that reduces mitochondrial overproduction of ROS. In this work, the antiplatelet effect of MitoQ through platelet adhesion and spreading, secretion, and aggregation was evaluated. Thus MitoQ, in a non-toxic effect, decreased platelet adhesion and spreading on collagen surface, and expression of P-selectin and CD63, and inhibited platelet aggregation induced by collagen, convulxin, thrombin receptor activator peptide-6 (TRAP-6), and phorbol 12-myristate 13-acetate (PMA). As an antiplatelet mechanism, we showed that MitoQ produced mitochondrial depolarization and decreased ATP secretion. Additionally, in platelets stimulated with antimycin A and collagen MitoQ significantly decreased ROS production. Our findings showed, for the first time, an antiplatelet effect of MitoQ that is probably associated with its mitochondrial antioxidant effect.

Asunto(s)

Antioxidantes/farmacología , Plaquetas/metabolismo , Compuestos Organofosforados/farmacología , Especies Reactivas de Oxígeno/metabolismo , Ubiquinona/análogos & derivados , Adenosina Trifosfato/metabolismo , Animales , Plaquetas/efectos de los fármacos , Células Cultivadas , Colágeno/metabolismo , Humanos , Ratones , Mitocondrias/metabolismo , Oligopéptidos/farmacología , Selectina-P/metabolismo , Ésteres del Forbol/farmacología , Activación Plaquetaria/efectos de los fármacos , Tetraspanina 30/metabolismo , Ubiquinona/farmacología

RESUMEN

INTRODUCTION: Colorectal cancer (CRC) is a critical health issue worldwide. The high rate of liver and lung metastasis associated with CRC creates a significant barrier to effective and efficient therapy. Tumour cells, including CRC cells, have metabolic alterations, such as high levels of glycolytic activity, increased cell proliferation and invasiveness, and chemo- and radio-resistance. However, the abnormally elevated mitochondrial transmembrane potential of these cells also provides an opportunity to develop drugs that selectively target the mitochondrial functions of tumour cells. METHODS: In this work, we used a new batch of benzoic acid esters with cytotoxic activities attached to the triphenylphosphonium group as a vehicle to target tumour mitochondria and improve their activity. We evaluated the cytotoxicity, selectivity, and mechanism of action of these derivatives, including the effects on energy stress-induced apoptosis and metabolic behaviour in the human CRC cell lines HCT-15 and COLO-205. RESULTS: The benzoic acid derivatives selectively targeted the tumour cells with high potency and efficacy. The derivatives induced the uncoupling of the oxidative phosphorylation system, decreased the transmembrane potential, and reduced ATP levels while increasing AMPK activation, thereby triggering tumour cell apoptosis in both tumour cell lines tested. CONCLUSION: The benzoic acid derivatives studied here are promising candidates for assessing in vivo models of CRC, despite the diverse metabolic characteristics of these tumour cells.

Asunto(s)

Antineoplásicos/farmacología , Benzoatos/farmacología , Neoplasias Colorrectales/tratamiento farmacológico , Compuestos Organofosforados/farmacología , Adenosina Trifosfato/metabolismo , Muerte Celular/efectos de los fármacos , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Humanos , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Mitocondrias/fisiología , Oxígeno/metabolismo

RESUMEN

The mitochondrion has emerged as a promising therapeutic target for novel cancer treatments because of its essential role in tumorigenesis and resistance to chemotherapy. Previously, we described a natural compound, 10-((2,5-dihydroxybenzoyl)oxy)decyl) triphenylphosphonium bromide (GA-TPP+C10), with a hydroquinone scaffold that selectively targets the mitochondria of breast cancer (BC) cells by binding to the triphenylphosphonium group as a chemical chaperone; however, the mechanism of action remains unclear. In this work, we showed that GA-TPP+C10 causes time-dependent complex inhibition of the mitochondrial bioenergetics of BC cells, characterized by (1) an initial phase of mitochondrial uptake with an uncoupling effect of oxidative phosphorylation, as previously reported, (2) inhibition of Complex I-dependent respiration, and (3) a late phase of mitochondrial accumulation with inhibition of α-ketoglutarate dehydrogenase complex (αKGDHC) activity. These events led to cell cycle arrest in the G1 phase and cell death at 24 and 48 h of exposure, and the cells were rescued by the addition of the cell-penetrating metabolic intermediates l-aspartic acid ß-methyl ester (mAsp) and dimethyl α-ketoglutarate (dm-KG). In addition, this unexpected blocking of mitochondrial function triggered metabolic remodeling toward glycolysis, AMPK activation, increased expression of proliferator-activated receptor gamma coactivator 1-alpha (pgc1α) and electron transport chain (ETC) component-related genes encoded by mitochondrial DNA and downregulation of the uncoupling proteins ucp3 and ucp4, suggesting an AMPK-dependent prosurvival adaptive response in cancer cells. Consistent with this finding, we showed that inhibition of mitochondrial translation with doxycycline, a broad-spectrum antibiotic that inhibits the 28 S subunit of the mitochondrial ribosome, in the presence of GA-TPP+C10 significantly reduces the mt-CO1 and VDAC protein levels and the FCCP-stimulated maximal electron flux and promotes selective and synergistic cytotoxic effects on BC cells at 24 h of treatment. Based on our results, we propose that this combined strategy based on blockage of the adaptive response induced by mitochondrial bioenergetic inhibition may have therapeutic relevance in BC.

Asunto(s)

Antineoplásicos/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Mitocondrias/efectos de los fármacos , Biosíntesis de Proteínas/efectos de los fármacos , Quinasas de la Proteína-Quinasa Activada por el AMP , Apoptosis/efectos de los fármacos , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Proliferación Celular/efectos de los fármacos , Doxiciclina/farmacología , Sinergismo Farmacológico , Femenino , Gentisatos/química , Gentisatos/farmacología , Compuestos Heterocíclicos/química , Compuestos Heterocíclicos/farmacología , Humanos , Complejo Cetoglutarato Deshidrogenasa/antagonistas & inhibidores , Complejo Cetoglutarato Deshidrogenasa/genética , Mitocondrias/patología , Compuestos Organofosforados/química , Compuestos Organofosforados/farmacología , Fosforilación Oxidativa/efectos de los fármacos , Proteínas Quinasas/genética , Ribosomas/efectos de los fármacos

RESUMEN

An in silico analysis of the interaction between the complex-ligands of nine acetylcholinesterase (AChE) structures of Lepidopteran organisms and 43 organophosphorus (OPs) pesticides with previous resistance reports was carried out. To predict the potential resistance by structural modifications in Lepidoptera insects, due to proposed point mutations in AChE, a broad analysis was performed using computational tools, such as homology modeling and molecular docking. Two relevant findings were revealed: (1) Docking results give a configuration of the most probable spatial orientation of two interacting molecules (AChE enzyme and OP pesticide) and (2) a predicted ΔGb. The mutations evaluated in the form 1 acetylcholinesterase (AChE-1) and form 2 acetylcholinesterase (AChE-2) structures of enzymes do not affect in any way (there is no regularity of change or significant deviations) the values of the binding energy (ΔGb) recorded in the AChE-OPs complexes. However, the mutations analyzed in AChE are associated with a structural modification that causes an inadequate interaction to complete the phosphorylation of the enzyme.

Asunto(s)

Acetilcolinesterasa/química , Acetilcolinesterasa/genética , Resistencia a los Insecticidas/efectos de los fármacos , Resistencia a los Insecticidas/genética , Lepidópteros/genética , Compuestos Organofosforados/farmacología , Plaguicidas/farmacología , Mutación Puntual/efectos de los fármacos , Animales , Biología Computacional/métodos , Simulación por Computador , Lepidópteros/efectos de los fármacos , Lepidópteros/enzimología , Simulación del Acoplamiento Molecular , Compuestos Organotiofosforados/química , Fragmentos de Péptidos , Fosforamidas/química , Alineación de Secuencia , Homología Estructural de Proteína

RESUMEN

Intoxications caused by organophosphorus compounds (OPs) are associated with the reversible, and sometimes irreversible interaction with acetylcholinesterase (AChE). OPs are commonly used as pesticides mainly in developing countries, where the associated poisoning is a major health problem related to suicidal attempts, careless manipulation, and chemical warfare. The current antidotes are oxime-based drugs that can regenerate the AChE catalytic activity. Nevertheless, challenges associated with lack of efficiency and difficulties for crossing blood-brain barrier have motivated the design of novel alternatives. We used a validated molecular docking approach for the virtual screening of 579,890 synthetic ligands and 478 drugs against a human AChE in its apo conformation, and a murine AChE conjugated with the OP tabun. After filtering, 7 hits were selected as potential competitors due to the formation of key interactions within the active site gorge of the AChE structure, and potential reactivators based on interactions with amino acids of the catalytic triad in the presence of organophosphorus compounds. The selected candidates will be further evaluated through in vitro and in vivo assays.

Asunto(s)

Acetilcolinesterasa/química , Acetilcolinesterasa/metabolismo , Inhibidores de la Colinesterasa/química , Inhibidores de la Colinesterasa/farmacología , Evaluación Preclínica de Medicamentos/métodos , Ligandos , Sitios de Unión/efectos de los fármacos , Biocatálisis/efectos de los fármacos , Bases de Datos Farmacéuticas , Humanos , Estructura Molecular , Compuestos Organofosforados/antagonistas & inhibidores , Compuestos Organofosforados/farmacología , Oximas/química , Oximas/farmacología , Relación Estructura-Actividad

RESUMEN

Chagas disease is caused by the hemoflagellate protozoa Trypanosoma cruzi and is one of the most important neglected tropical diseases, especially in Latin American countries, where there is an association between low-income populations and mortality. The nitroderivatives used in current chemotherapy are far from ideal and present severe limitations, justifying the continuous search for alternative drugs. Since the1990s, our group has been investigating the trypanocidal activity of natural naphthoquinones and their derivatives, and three naphthoimidazoles (N1, N2 and N3) derived from ß-lapachone were found to be most effective in vitro. Analysis of their mechanism of action via cellular, molecular and proteomic approaches indicates that the parasite mitochondrion contains one of the primary targets of these compounds, trypanothione synthetase (involved in trypanothione production), which is overexpressed after treatment with these compounds. Here, we further evaluated the participation of the mitochondria and reactive oxygen species (ROS) in the anti-T. cruzi action of naphthoimidazoles. Preincubation of epimastigotes and trypomastigotes with antioxidants (α-tocopherol and urate) strongly protected the parasites from the trypanocidal effect of naphthoimidazoles, decreasing the ROS levels produced and reverting the mitochondrial swelling phenotype. The addition of pro-oxidants (menadione and H2O2) before the treatment induced an increase in parasite lysis. Despite the O2 uptake and mitochondrial complex activity being strongly reduced by N1, N2 and N3, urate partially restored the mitochondrial metabolism only in N1-treated parasites. In parallel, MitoTEMPO, a mitochondrial-targeted antioxidant, protected the functionality of the mitochondria in N2- and N3-treated parasites. In addition, the trypanothione reductase activity was remarkably increased after treatment with N1 and N3, and molecular docking demonstrated that these two compounds were positioned in pockets of this enzyme. Based on our findings, the direct impairment of the mitochondrial electron transport chain by N2 and N3 led to an oxidative misbalance, which exacerbated ROS generation and led to parasite death. Although other mechanisms cannot be discounted, mainly in N1-treated parasites, further investigations are required.

Asunto(s)

Enfermedad de Chagas/tratamiento farmacológico , Mitocondrias/efectos de los fármacos , Naftoquinonas/farmacología , Trypanosoma cruzi/efectos de los fármacos , Animales , Enfermedad de Chagas/genética , Enfermedad de Chagas/parasitología , Humanos , Peróxido de Hidrógeno , Imidazoles/química , Imidazoles/farmacología , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Mitocondrias/patología , Dilatación Mitocondrial/efectos de los fármacos , Naftoquinonas/química , Compuestos Organofosforados/farmacología , Piperidinas/farmacología , Proteómica , Especies Reactivas de Oxígeno/metabolismo , Tripanocidas/química , Tripanocidas/farmacología , Trypanosoma cruzi/patogenicidad

RESUMEN

The objective of this study was to evaluate NBPT, zeolite and humic acid in different concentrations as inhibitors of the activity of the enzyme urease. The activity of the urease enzyme was quantified by the methods proposed by May and Douglas (1976) and Witte and Medina-Escobar (2001). For this reason, two experiments were conducted in a completely randomized design in split plots, in which the incubation periods are the plots and the fertilizers with the inhibitors at the different concentrations are the subplots with three replications. Fifteen fertilizers based on NBPT-coated urea, humic acid and zeolite were used in different concentrations. The two methods of analysis used in the experiment confirmed the efficiency of NBPT in inhibiting the enzymatic action even at low concentration, with 0.02% (m/m) being sufficient to inhibit urease, with no difference between inhibitor concentrations. The addition of humic acid reduced the activity of urease after 36 hours of reaction when the activity of the enzyme was evaluated by the method proposed by May and Douglas (1976). Zeolite did not influence the activity of the urease enzyme when analyzed by the May and Douglas method (1976).

Asunto(s)

Inhibidores Enzimáticos/farmacología , Sustancias Húmicas , Compuestos Organofosforados/farmacología , Suelo/química , Urea/farmacología , Ureasa/antagonistas & inhibidores , Zeolitas/farmacología , Fertilizantes

RESUMEN

Tapping Panel Dryness (TPD) affects latex production in Hevea brasiliensis. This physiological syndrome involves the agglutination of rubber particles, which leads to partial or complete cessation of latex flow. Latex harvesting consists in tapping soft bark. Ethephon can be applied to stimulate latex flow and its regeneration in laticifers. Several studies have reported transcriptome changes in bark tissues. This study is the first report on deep RNA sequencing of latex to compare the effect of ethephon stimulation and TPD severity. Trees were carefully selected for paired-end sequencing using an Illumina HiSeq 2000. In all, 43 to 60 million reads were sequenced for each treatment in three biological replicates (slight TPD trees without ethephon stimulation, and slight and severe TPD trees with ethephon treatment). Differentially expressed genes were identified and annotated, giving 8,111 and 728 in response to ethephon in slight TPD trees and in ethephon-induced severe TPD trees, respectively. A biological network of responses to ethephon and TPD highlighted the major influence of metabolic processes and the response to stimulus, especially wounding and jasmonate depression in TPD-affected trees induced by ethephon stimulation.

Asunto(s)

Hevea/genética , Compuestos Organofosforados/farmacología , Reguladores del Crecimiento de las Plantas/farmacología , Transducción de Señal/efectos de los fármacos , Transcriptoma/efectos de los fármacos , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Redes Reguladoras de Genes/efectos de los fármacos , Hevea/metabolismo , Látex/biosíntesis , Corteza de la Planta/genética , Corteza de la Planta/metabolismo , Enfermedades de las Plantas/genética , Análisis de Componente Principal , ARN de Planta/química , ARN de Planta/aislamiento & purificación , ARN de Planta/metabolismo , Análisis de Secuencia de ARN

RESUMEN

The addition of organic residues to agricultural soils has been used as a practical alternative to improve crop quality and health. The objective of this work was to evaluate maize physiological and nutritional responses to the application of compost and biochar combined with urea (N) and N-(n-butyl) thiophosphoric triamide (NBPT). The experiment was performed in plastic pots with 3 kg of soil under greenhouse conditions for 30 days. The compost and biochar were applied at the rate of 0.3 ton ha-1, using an amount of nutrient (nitrogen, phosphorus and potassium) demanded by crop growth. The physiological responses of maize were monitored by measuring the plant height, stalk diameter, leaf chlorophyll content, shoot dry weight and root dry weight. The nutritional responses of maize were assessed by using the nutrient concentration and the total nutrient assimilation by the plants. The results showed that the addition of compost or biochar did not alter the maize physiological response compared to the addition of mineral fertilizer used under the same conditions. However, a difference occurred in the maize nutritional responses to the compost and biochar amendments combined with urea and NBPT. The greatest N concentration in maize was observed in the treatment consisting of biochar combined with urea + NBPT. All the treatments in which compost or biochar was applied in combination with urea and NBPT presented greater total N assimilation compared to the treatment with conventional fertilization. The results of this survey showed that the combination of urea and NBPT improved the nitrogen-use efficiency of maize.

Asunto(s)

Carbón Orgánico/farmacología , Nitrógeno/metabolismo , Compuestos Organofosforados/farmacología , Urea/farmacología , Zea mays/crecimiento & desarrollo , Clorofila/análisis , Compostaje/métodos , Productos Agrícolas , Evaluación Nutricional , Raíces de Plantas/efectos de los fármacos , Suelo/química , Urea/administración & dosificación , Zea mays/anatomía & histología , Zea mays/efectos de los fármacos

RESUMEN

BACKGROUND: Pomegranate (Punica granatum) is a non-climacteric fruit susceptible to chilling injury (CI) at temperatures below 5 °C. To understand the influences of ethylene and modified atmosphere on CI physiological disorders of pomegranate, exogenous ethrel (0.5, 1 and 1.5 µg L-1 ) treatments, 1-methylcyclopropene (1-MCP) (1 µL L-1 ) exposure, packaging in a modified atmosphere (MAP) (XTend™ bags; StePac, São Paulo, Brazil), a MAP/1-MCP combination, and packaging in macro-perforated bags (MPB) were applied. The treated fruits were cold stored (2 ± 1 °C; 85% relative humidity) and sampled during 120 + 3 days at 20 °C. RESULTS: During cold storage, CI symptoms started at 20 days in MPB and at 60 days for all exogenous ethylene treatments, and were delayed to 120 days in MAP, 1-MCP and MAP/1-MCP treatments. MPB and ethylene treatments induced significant electrolyte leakage, oxidative damage, lipid peroxidation, ethylene and CO2 production, and 1-aminocyclopropane-1-carboxylic acid oxidase activity, without any change in total soluble solids, titratable acidity or skin and aril colours. Conversely, MAP by itself, or in combination with 1-MCP application, effectively delayed CI symptoms. CONCLUSION: During long-term cold storage of this non-climacteric fruit, ethrel application induced endogenous ethylene biosynthesis, accelerating the appearance of CI symptoms in contrast to the observations made for MAP and 1-MCP treatments. © 2018 Society of Chemical Industry.

Asunto(s)

Ciclopropanos/farmacología , Conservación de Alimentos/métodos , Frutas/química , Lythraceae/efectos de los fármacos , Compuestos Organofosforados/farmacología , Atmósfera/análisis , Frío , Embalaje de Alimentos , Almacenamiento de Alimentos , Frutas/efectos de los fármacos , Lythraceae/química

RESUMEN

We previously demonstrated that alkyl gallates coupled to triphenylphosphine have a selective and efficient antiproliferative effect by inducing mitochondrial uncoupling in vitro due to the increased mitochondrial transmembrane potential of tumor cells. Therefore, in this work, the in vivo antitumor activities of alkyl gallate triphenylphosphonium derivatives (TPP+C8, TPP+C10 and TPP+C12) were evaluated in a syngeneic murine model of breast cancer. We found that TPP+C10 increased the cytosolic ADP/ATP ratio and significantly increased the AMP levels in a concentration-dependent manner in TA3/Ha murine mammary adenocarcinoma cells. Interestingly, TPP+C10 induced a decrease in the levels of cellular proliferation markers and promoted caspase-3 activation in tumor-bearing mice. Additionally, TPP+C10 inhibited tumor growth in the syngeneic mouse model. Importantly, 30days of intraperitoneal (i.p.) administration of the combination of TPP+C10 (10mg/kg/48h) and the antibiotic doxycycline (10mg/kg/24h) completely eliminated the subcutaneous tumor burden in mice (n=6), without any relapses at 60days post-treatment. This enhancement of the individual activities of TPP+C10 and doxycycline is due to the uncoupling of oxidative phosphorylation by TPP+C10 and the inhibition of mitochondrial biogenesis by doxycycline, as demonstrated by loss of mitochondrial mass and overexpression of PGC1-α as an adaptive response. Moreover, i.p. administration of TPP+C10 (10mg/kg/24h) to healthy mice did not produce toxicity or damage in organs important for drug metabolism and excretion, as indicated by hematological, biochemical and histological assessments. These findings suggest that the combination of TPP+C10 with doxycycline is a valuable candidate therapy for breast cancer management.

Asunto(s)

Adenocarcinoma/tratamiento farmacológico , Antineoplásicos/farmacología , Neoplasias de la Mama Masculina/tratamiento farmacológico , Ácido Gálico/farmacología , Neoplasias Mamarias Experimentales/tratamiento farmacológico , Compuestos Organofosforados/farmacología , Adenocarcinoma/genética , Adenocarcinoma/metabolismo , Adenocarcinoma/patología , Adenosina Trifosfato/metabolismo , Animales , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Apoptosis/efectos de los fármacos , Neoplasias de la Mama Masculina/genética , Neoplasias de la Mama Masculina/metabolismo , Neoplasias de la Mama Masculina/patología , Caspasa 3/metabolismo , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Doxiciclina/farmacología , Ácido Gálico/análogos & derivados , Masculino , Neoplasias Mamarias Experimentales/genética , Neoplasias Mamarias Experimentales/metabolismo , Neoplasias Mamarias Experimentales/patología , Ratones , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Mitocondrias/patología , Biogénesis de Organelos , Fosforilación Oxidativa/efectos de los fármacos , Consumo de Oxígeno/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Factores de Tiempo , Carga Tumoral/efectos de los fármacos

RESUMEN

Butyryl cholinesterase (BChE) has been seen as a key enzyme in the search for new strategies in the treatment of poisoning by organophosphates (OPs), since human BChE (HssBChE), complexed with the appropriate oxime, can be a suitable scavenger and deactivator for OPs in the blood stream. However, the efficacy of HssBChE is limited by its strict stoichiometric scavenging, slow reactivation, and propensity for aging. The improvement of the reactivation rate by new and more efficient oximes could contribute to mitigate this problem and increase the HssBChE efficiency as scavenger. Several oximes have been synthesized and tested with this goal, some with promising results, but the mechanistic aspects of the reactivation reaction are not fully understood yet. In order to better investigate this mechanism, docking and mixed quantum and molecular mechanics combined with principal components analysis were performed here to evaluate the capacity of reactivation and determine the preferred route for the reactivation reaction of two new oximes on HssBChE inhibited by the neurotoxic agents cyclosarin and sarin. Plots of potential energies were calculated and all the transition states of the reactional mechanism were determined. Our results showed a good correlation with experimental data and pointed to the most efficient oxime with both OPs. The protocol used could be a suitable tool for a preliminary evaluation of the HssBChE reactivation rates by new oximes.

Asunto(s)

Butirilcolinesterasa/química , Inhibidores de la Colinesterasa/química , Reactivadores de la Colinesterasa/química , Compuestos Organofosforados/química , Oximas/química , Sarín/química , Inhibidores de la Colinesterasa/farmacología , Reactivadores de la Colinesterasa/farmacología , Humanos , Modelos Químicos , Modelos Moleculares , Compuestos Organofosforados/farmacología , Oximas/farmacología , Unión Proteica , Sarín/farmacología

RESUMEN

BACKGROUND: The new modalities for treating patients with non-muscle invasive bladder cancer (NMIBC) for whom BCG (Bacillus Calmette-Guerin) has failed or is contraindicated are recently increasing due to the development of new drugs. Although agents like mitomycin C and BCG are routinely used, there is a need for more potent and/or less-toxic agents. In this scenario, a new perspective is represented by P-MAPA (Protein Aggregate Magnesium-Ammonium Phospholinoleate-Palmitoleate Anhydride), developed by Farmabrasilis (non-profit research network). This study detailed and characterized the mechanisms of action of P-MAPA based on activation of mediators of Toll-like Receptors (TLRs) 2 and 4 signaling pathways and p53 in regulating angiogenesis and apoptosis in an animal model of NMIBC, as well as, compared these mechanisms with BCG treatment. RESULTS: Our results demonstrated the activation of the immune system by BCG (MyD88-dependent pathway) resulted in increased inflammatory cytokines. However, P-MAPA intravesical immunotherapy led to distinct activation of TLRs 2 and 4-mediated innate immune system, resulting in increased interferons signaling pathway (TRIF-dependent pathway), which was more effective in the NMIBC treatment. Interferon signaling pathway activation induced by P-MAPA led to increase of iNOS protein levels, resulting in apoptosis and histopathological recovery. Additionally, P-MAPA immunotherapy increased wild-type p53 protein levels. The increased wild-type p53 protein levels were fundamental to NO-induced apoptosis and the up-regulation of BAX. Furthermore, interferon signaling pathway induction and increased p53 protein levels by P-MAPA led to important antitumor effects, not only suppressing abnormal cell proliferation, but also by preventing continuous expansion of tumor mass through suppression of angiogenesis, which was characterized by decreased VEGF and increased endostatin protein levels. CONCLUSIONS: Thus, P-MAPA immunotherapy could be considered an important therapeutic strategy for NMIBC, as well as, opens a new perspective for treatment of patients that are refractory or resistant to BCG intravesical therapy.

Asunto(s)

Factores Inmunológicos/administración & dosificación , Ácidos Linoleicos/administración & dosificación , Neovascularización Patológica/tratamiento farmacológico , Compuestos Organofosforados/administración & dosificación , Receptores Toll-Like/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Neoplasias de la Vejiga Urinaria/tratamiento farmacológico , Administración Intravesical , Animales , Vacuna BCG/administración & dosificación , Vacuna BCG/farmacología , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Femenino , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Factores Inmunológicos/farmacología , Inmunoterapia/métodos , Ácidos Linoleicos/farmacología , Invasividad Neoplásica , Neoplasias Experimentales , Neovascularización Patológica/metabolismo , Compuestos Organofosforados/farmacología , Ratas , Regulación hacia Arriba , Neoplasias de la Vejiga Urinaria/irrigación sanguínea , Neoplasias de la Vejiga Urinaria/metabolismo

RESUMEN

Jatropha curcas L. has been identified for biofuel production but it presents limited commercial yields due to limited branching and a lack of yield uniformity. The objective of this study was to evaluate the effects of single application of ethephon or a combination of 6-benzyladenine (BA) with gibberellic acid isomers A4 and A7 (GA4+7) on branch induction, flowering and fruit production in jatropha plants with and without leaves. Plants with and without leaves showed differences for growth and reproductive variables. For all variables except inflorescence set, there were no significant statistical interactions between the presence of leaves and plant growth regulators concentration. The total number of flowers per inflorescence was reduced as ethephon concentration was increased. As BA + GA4 +7 concentration increased, seed dry weight increased. Thus, ethephon and BA + GA4 +7 applications appeared to affect flowering and seed production to a greater extent than branching. The inability to discern significant treatment effects for most variables might have been due to the large variability within plant populations studied and thus resulting in an insufficient sample size. Therefore, data collected from this study were used for statistical estimations of sample sizes to provide a reference for future studies.

Asunto(s)

Aminobutiratos/farmacología , Compuestos de Bencilo/farmacología , Giberelinas/farmacología , Jatropha/efectos de los fármacos , Compuestos Organofosforados/farmacología , Reguladores del Crecimiento de las Plantas/farmacología , Purinas/farmacología , Flores , Frutas , Jatropha/crecimiento & desarrollo