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1.
Molecules ; 27(2)2022 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-35056867

RESUMEN

The indigenous purplish red fruit, Cleistocalyx nervosum var. paniala (CN), is grown in northern Thailand. The aqueous extract of CN pulp is known to exhibit antioxidant and anticarcinogenic properties. To search for an antioxidant fraction separated from CN, various hydroalcoholic extractions were performed. The acidified ethanolic extract of CN obtained from 0.5% (v/v) citric acid in 80% (v/v) ethanol yielded greater polyphenol content and DPPH radical scavenging activity when compared with other hydroethanolic extracts. Cyanidin-3-glucoside is a major anthocyanin present in the acidified ethanolic extract of CN (AECN). At a dose of 5000 mg/kg bw, an anthocyanin-rich extract was found to be safe when given to rats without any acute toxicity. To examine the hepatoprotective properties of AECN, an overdose of acetaminophen (APAP) was induced in a rat model, while silymarin was used as a standard reference. The administration of AECN at a dose of 300 mg/kg bw for 28 days improved hepatocyte architecture and modulated serum alanine aminotransferase levels in APAP-induced rats. Furthermore, it significantly decreased serum and hepatic malondialdehyde levels but increased hepatic glutathione content, as well as glutathione peroxidase and UDP-glucuronosyltransferase activities. In conclusion, AECN may effectively reduce oxidative stress induced acute hepatotoxicity in overdose APAP-treated rats through the suppression of oxidative stress and the enhancement of the antioxidant system in rat livers.


Asunto(s)
Acetaminofén/efectos adversos , Antioxidantes/farmacología , Enfermedad Hepática Inducida por Sustancias y Drogas/prevención & control , Extractos Vegetales/farmacología , Sustancias Protectoras/farmacología , Syzygium/química , Alanina Transaminasa/sangre , Animales , Antocianinas , Antioxidantes/uso terapéutico , Antioxidantes/toxicidad , Enfermedad Hepática Inducida por Sustancias y Drogas/sangre , Enfermedad Hepática Inducida por Sustancias y Drogas/patología , Modelos Animales de Enfermedad , Enzimas/efectos de los fármacos , Enzimas/metabolismo , Etanol/química , Femenino , Frutas/química , Glutatión/metabolismo , Glutatión Peroxidasa/metabolismo , Hígado/efectos de los fármacos , Hígado/enzimología , Malondialdehído/metabolismo , Estrés Oxidativo/efectos de los fármacos , Extractos Vegetales/uso terapéutico , Extractos Vegetales/toxicidad , Polifenoles/análisis , Polifenoles/farmacología , Polifenoles/uso terapéutico , Sustancias Protectoras/uso terapéutico , Sustancias Protectoras/toxicidad , Ratas Wistar , Silimarina/farmacología , Silimarina/uso terapéutico , Tailandia
2.
Molecules ; 26(19)2021 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-34641604

RESUMEN

Heavy metals enter the human body through the gastrointestinal tract, skin, or via inhalation. Toxic metals have proven to be a major threat to human health, mostly because of their ability to cause membrane and DNA damage, and to perturb protein function and enzyme activity. These metals disturb native proteins' functions by binding to free thiols or other functional groups, catalyzing the oxidation of amino acid side chains, perturbing protein folding, and/or displacing essential metal ions in enzymes. The review shows the physiological and biochemical effects of selected toxic metals interactions with proteins and enzymes. As environmental contamination by heavy metals is one of the most significant global problems, some detoxification strategies are also mentioned.


Asunto(s)
Biodegradación Ambiental , Exposición a Riesgos Ambientales , Metales Pesados/toxicidad , Unión Proteica/efectos de los fármacos , Sitios de Unión , Cosméticos/toxicidad , Daño del ADN , Contaminantes Ambientales/toxicidad , Enzimas/efectos de los fármacos , Alimentos/toxicidad , Humanos , Pliegue de Proteína/efectos de los fármacos
3.
J Pharmacol Toxicol Methods ; 112: 107107, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34363961

RESUMEN

Administration of a compound can induce drug-metabolizing enzymes (DMEs) in the liver. DME induction can affect various parameters in toxicology studies. Therefore, evaluation of DME induction is important for interpreting test compound-induced biological responses. Several methods such as measurement of hepatic microsomal DME activity using substrates, electron microscopy, or immunohistochemistry have been used; however, these methods are limited in throughput and specificity or are not quantitative. Liquid chromatography mass spectrometry (LC/MS)-based protein analysis can detect and quantify multiple proteins simultaneously per assay. Studies have shown that formalin-fixed paraffin-embedded (FFPE) samples, which are routinely collected in toxicology studies, can be used for LC/MS-based protein analysis. To validate the utility of LC/MS using FFPE samples for quantitative evaluation of DME induction, we treated rats with a DME inducer, phenobarbital, and compared the protein expression levels of 13 phase-I and 11 phase-II DMEs between FFPE and fresh frozen hepatic samples using LC/MS. A good correlation between data from FFPE and frozen samples was obtained after analysis. In FFPE and frozen samples, the expression of 6 phase-I and 8 phase-II DMEs showed a similar significant increase and a prominent rise in Cyp2b2 and Cyp3a1 levels. In addition, LC/MS data were consistent with the measurement of microsomal DME activities. These results suggest that LC/MS-based protein expression analysis using FFPE samples is as effective as that using frozen samples for detecting DME induction.


Asunto(s)
Proteómica , Espectrometría de Masas en Tándem , Animales , Cromatografía Liquida , Enzimas/efectos de los fármacos , Hígado , Adhesión en Parafina , Fenobarbital/metabolismo , Fenobarbital/toxicidad , Proteómica/métodos , Ratas , Fijación del Tejido
4.
Pharmacol Res ; 169: 105660, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33971270

RESUMEN

Dysregulation and mutations of protein kinases play causal roles in many diseases including cancer. The KLIFS (kinase-ligand interaction fingerprint and structure) catalog includes 85 ligand binding-site residues occurring in both the small and large protein kinase lobes. Except for allosteric inhibitors, all FDA-approved drug-target enzyme complexes display hydrophobic interactions involving catalytic spine residue-6 (KLIFS-77), catalytic spine residue-7 (KLIFS-11), and catalytic spine residue-8 (KLIFS-15) within the small lobe and residues within the hinge-linker region (KLIFS-46-52). Except for allosteric antagonists, the approved drugs form hydrogen bonds with the third hinge residue (KLIFS-48) of their target. Most of the approved drugs, including the allosteric inhibitors, interact with the small lobe gatekeeper residue (KLIFS-45). The type IIA inhibitors have the most hydrophobic interactions with their target enzymes. These include interactions with KLIFS-27/31/35/61/66 residues of the back pocket within both the small and large lobes. There is also interaction with KLIFS-68 (regulatory spine residue-1), the conserved histidine of the catalytic loop that is found in the back pocket of type II antagonists, but within the front pocket of the other types of inhibitors. Owing to the participation of protein kinase signaling cascades in a wide variety of physiological and pathological processes, one can foresee the increasing use of targeted inhibitors both as primary and secondary treatments for many illnesses. Further studies of protein kinase signal transduction pathways promise to yield new and actionable information that will serve as a basis for fundamental and applied biomedical breakthroughs.


Asunto(s)
Interacciones Hidrofóbicas e Hidrofílicas , Inhibidores de Proteínas Quinasas/química , Sitios de Unión , Enzimas/química , Enzimas/efectos de los fármacos , Humanos , Interacciones Hidrofóbicas e Hidrofílicas/efectos de los fármacos , Inhibidores de Proteínas Quinasas/farmacología , Relación Estructura-Actividad
5.
Br J Nutr ; 125(3): 251-259, 2021 02 14.
Artículo en Inglés | MEDLINE | ID: mdl-32718368

RESUMEN

Coated copper sulphate (CCS) could be used as a Cu supplement in cows. To investigate the influences of copper sulphate (CS) and CCS on milk performance, nutrient digestion and rumen fermentation, fifty Holstein dairy cows were arranged in a randomised block design to five groups: control, CS addition (7·5 mg Cu/kg DM from CS) or CCS addition (5, 7·5 and 10 mg Cu/kg DM from CCS, respectively). When comparing Cu source at equal inclusion rates (7·5 mg/kg DM), cows receiving CCS addition had higher yields of fat-corrected milk, milk fat and protein; digestibility of DM, organic matter (OM) and neutral-detergent fibre (NDF); ruminal total volatile fatty acid (VFA) concentration; activities of carboxymethyl cellulase, cellobiase, pectinase and α-amylase; populations of Ruminococcus albus, Ruminococcus flavefaciens and Fibrobacter succinogenes; and liver Cu content than cows receiving CS addition. Increasing CCS addition, DM intake was unchanged, yields of milk, milk fat and protein; feed efficiency; digestibility of DM, OM, NDF and acid-detergent fibre; ruminal total VFA concentration; acetate:propionate ratio; activity of cellulolytic enzyme; populations of total bacteria, protozoa and dominant cellulolytic bacteria; and concentrations of Cu in serum and liver increased linearly, but ruminal propionate percentage, ammonia-N concentration, α-amylase activity and populations of Prevotella ruminicola and Ruminobacter amylophilus decreased linearly. The results indicated that supplement of CS could be substituted with CCS and addition of CCS improved milk performance and nutrient digestion in dairy cows.


Asunto(s)
Alimentación Animal , Fenómenos Fisiológicos Nutricionales de los Animales/efectos de los fármacos , Sulfato de Cobre/administración & dosificación , Suplementos Dietéticos , Animales , Bovinos , Digestión/efectos de los fármacos , Enzimas/efectos de los fármacos , Femenino , Fermentación/efectos de los fármacos , Lactancia/efectos de los fármacos , Hígado/metabolismo , Microbiota/efectos de los fármacos , Nutrientes/metabolismo , Rumen/metabolismo
6.
FEMS Microbiol Lett ; 367(19)2020 10 16.
Artículo en Inglés | MEDLINE | ID: mdl-33016320

RESUMEN

We used error-prone PCR to generate mutations in a subtilisin protease-encoding gene, and screened for recombinants that expressed temperature-sensitive (TS) variants. From the dozens of mutations that we detected in the recombinant genes we found that those mutations that affected aspartate-75 had the most profound effect on temperature stability. We thus focused our analysis on two variants of subtilisin C, the more heat-sensitive variant 24 (V24), with amino acid changes D75G, L234M and Q274P; and variant 25 (V25), with a single amino acid change, D75A. For V24 a two log-fold reduction in activity occurs in under 10 min at 50°C. For V25, a two log-fold reduction occurs at 60°C, a temperature that reduces the activity of the wild type enzyme by about 30%. The V24 variant fully inactivates enzymes commonly used in molecular biology research and in molecular diagnostics, and is stabilized against autolysis with propylene glycol concentrations of 10% or greater. The subtilisin variants are produced by a strain of Bacillus subtilis that lacks expression of its native secreted proteases, and the variants can be isolated from the supernatants using nickel affinity chromatography.


Asunto(s)
Enzimas/efectos de los fármacos , Proteínas Recombinantes/metabolismo , Subtilisina/farmacología , Bacillus subtilis/enzimología , Bacillus subtilis/genética , Activación Enzimática , Proteínas Recombinantes/genética , Subtilisina/genética , Subtilisina/metabolismo , Temperatura
7.
Biochemistry ; 59(38): 3517-3522, 2020 09 29.
Artículo en Inglés | MEDLINE | ID: mdl-32931253

RESUMEN

We define paracatalysis as the acceleration of a reaction that appears abnormal or nonphysiological. With the high specificity of enzymes, side reactivity of this kind is typically negligible. However, enzyme paracatalysis can be amplified to levels that are biologically significant through interactions with a special class of small molecule "antagonist", here termed a paracatalytic inducer. Compounds with this unusual mode of action tend to be natural products, identified by chance through phenotypic screens. In this Perspective, we suggest two general types of paracatalytic inducer. The first type promotes substrate ambiguity, where the enzyme's ground state selectivity is compromised, enabling the transformation of non-native substrates. The second type involves transition state ambiguity, where the paracatalytic inducer changes the enzyme's interactions with the activated substrate, giving rise to non-native bond making. Although they are unusual, small molecules that induce paracatalysis have established value as hypothesis-generating probes and a few substances, i.e., aspirin and the aminoglycosides, have proven to be translatable as medicines.


Asunto(s)
Biocatálisis/efectos de los fármacos , Activadores de Enzimas/farmacología , Inhibidores Enzimáticos/farmacología , Enzimas/efectos de los fármacos , Especificidad por Sustrato/efectos de los fármacos
8.
Chemosphere ; 245: 125611, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31864057

RESUMEN

Lead-contaminated soils are becoming an ecological risk to the environment because of producing low-quality food which is directly causing critical health issues in humans and animals. We hypothesized that incorporation of dicalcium phosphate (DCP), eggshell powder (ESP) and biochar (BH) at diverse rates into a Pb-affected soil can proficiently immobilize Pb and decline its bioavailability to spinach (Spinacia oleracea L.). A soil was artificially spiked with Pb concentration (at 600 mg kg-1) and further amended with DCP, ESP, and BH (as sole treatments at 2% and in concoctions at 1% each) for immobilization of Pb in the soil. The interlinked effects of applied treatments on Pb concentrations in shoots and roots, biomass, antioxidants, biochemistry, and nutrition of spinach were also investigated. Results depicted that the highest reduction in DTPA-extractable Pb and the concentrations of Pb in shoots and roots was achieved in DCP1%+BH1% treatment that was up to 58%, 66%, and 53%, respectively over control. Likewise, the DCP1%+BH1% treatment also showed the maximum shoot and root dry weight (DW), chlorophyll-a (Chl-a) and chlorophyll-b (Chl-b) contents and relative water content (RWC) in spinach up to 92%, 121%, 60%, 65%, and 30%, respectively, compared to control. Likewise, DCP1%+BH1% treatment noticeably improved antioxidant enzymes, biochemistry, and nutrition in the leaves. Moreover, the DCP1%+BH1% treatment depicted mostly enhanced activities of dehydrogenase, catalase, acid phosphatase, alkaline phosphatase, phosphomonoesterase, urease, protease and B-glucosidase in the post-harvested soil up to 118%, 345%, 55%, 92%, 288%, 107%, 53% and 252%, respectively over control.


Asunto(s)
Fosfatos de Calcio/química , Carbón Orgánico/química , Plomo/aislamiento & purificación , Pistacia/química , Suelo/química , Spinacia oleracea/metabolismo , Antioxidantes/metabolismo , Disponibilidad Biológica , Fosfatos de Calcio/farmacología , Carbón Orgánico/farmacología , Enzimas/efectos de los fármacos , Valor Nutritivo , Hojas de la Planta/metabolismo , Contaminantes del Suelo/análisis
9.
Chemosphere ; 242: 125228, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31677507

RESUMEN

The uptake and accumulation of three imidazolium ionic liquids with different alkyl chain lengths ([C2min]Br, [C4min]Br, [C8min]Br) in rice seedlings were investigated. All three different ILs were primarily accumulated in roots, while only a little amount of ILs were translocated and accumulated in stems and leaves. Accumulation and transportation of ILs in rice depend on the concentration and the alkyl chain length of ILs. ILs contents in the roots, stems and leaves decreased as ILs alkyl chain length increased. Growth inhibition results showed that the toxic effects of ILs on rice growth depends on the alkyl chain length: [C8min]Br >[C4min]Br >[C2min]Br. As markers of defense and phytotoxicity, the plant antioxidant enzymes and biochemical stress responses were also assessed. All different ILs significantly increased malondialdehyde (MDA), catalase (CAT), peroxidase (POD) and dismutase (SOD) activities in rice tissue. Compared to the control group, the contents of chlorophyll a reduced by 59.56%, 62.28% and 69.74% after addition of [C2min]Br, [C4min]Br, and [C8min]Br, respectively. This study provides important information for a better understanding on the uptake and accumulation of imidazolium ILs by agricultural plants.


Asunto(s)
Imidazoles/farmacocinética , Líquidos Iónicos/farmacocinética , Oryza/efectos de los fármacos , Plantones/efectos de los fármacos , Antioxidantes/análisis , Clorofila A/metabolismo , Enzimas/efectos de los fármacos , Enzimas/metabolismo , Imidazoles/química , Líquidos Iónicos/química , Líquidos Iónicos/toxicidad , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/metabolismo , Relación Estructura-Actividad
10.
ACS Nano ; 13(8): 9363-9375, 2019 08 27.
Artículo en Inglés | MEDLINE | ID: mdl-31314989

RESUMEN

Drugs that influence enzymes of lipid metabolism can cause pathological accumulation of lipids in animal cells. Here, gold nanoparticles, acting as nanosensors that deliver surface-enhanced Raman scattering (SERS) spectra from living cells provide molecular evidence of lipid accumulation in lysosomes after treatment of cultured cells with the three tricyclic antidepressants (TCA) desipramine, amitryptiline, and imipramine. The vibrational spectra elucidate to great detail and with very high sensitivity the composition of the drug-induced lipid accumulations, also observed in fixed samples by electron microscopy and X-ray nanotomography. The nanoprobes show that mostly sphingomyelin is accumulated in the lysosomes but also other lipids, in particular, cholesterol. The observation of sphingomyelin accumulation supports the impairment of the enzyme acid sphingomyelinase. The SERS data were analyzed by random forest based approaches, in particular, by minimal depth variable selection and surrogate minimal depth (SMD), shown here to be particularly useful machine learning tools for the analysis of the lipid signals that contribute only weakly to SERS spectra of cells. SMD is used for the identification of molecular colocalization and interactions of the drug molecules with lipid membranes and for discriminating between the biochemical effects of the three different TCA molecules, in agreement with their different activity. The spectra also indicate that the protein composition is significantly changed in cells treated with the drugs.


Asunto(s)
Técnicas Biosensibles , Enzimas/efectos de los fármacos , Producto de la Acumulación de Lípidos , Nanopartículas/química , Esfingomielina Fosfodiesterasa/antagonistas & inhibidores , Colesterol/química , Colesterol/aislamiento & purificación , Inhibidores Enzimáticos/farmacología , Oro/química , Lípidos/química , Lípidos/aislamiento & purificación , Lisosomas/química , Lisosomas/efectos de los fármacos , Nanopartículas del Metal , Espectrometría Raman , Esfingomielina Fosfodiesterasa/química , Esfingomielinas/química
11.
J Inherit Metab Dis ; 42(6): 1088-1096, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31177541

RESUMEN

Abundance of urea cycle enzymes in the liver is regulated by dietary protein intake. Although urea cycle enzyme levels rise in response to a high-protein (HP) diet, signaling networks that sense dietary protein intake and trigger changes in expression of urea cycle genes have not been identified. The aim of this study was to identify signaling pathway(s) that respond to changes in protein intake and regulate expression of urea cycle genes in mice and human hepatocytes. Mice were adapted to either HP or low-protein diets followed by isolation of liver protein and mRNA and integrated analysis of the proteomic and transcriptomic data. HP diet led to increased expression of mRNA and enzymes in amino acid degradation pathways and decreased expression of mRNA and enzymes in carbohydrate and fat metabolism, which implicated adenosine monophosphate-activated protein kinase (AMPK) as a possible regulator. Primary human hepatocytes, treated with 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) an activator of AMPK, were used to test whether AMPK regulates expression of urea cycle genes. The abundance of carbamoylphosphate synthetase 1 and ornithine transcarbamylase mRNA increased in hepatocytes treated with AICAR, which supports a role for AMPK signaling in regulation of the urea cycle. Because AMPK is either a target of drugs used to treat type-2 diabetes, these drugs might increase the expression of urea cycle enzymes in patients with partial urea cycle disorders, which could be the basis of a new therapeutic approach.


Asunto(s)
Proteínas Quinasas Activadas por AMP/metabolismo , Proteínas en la Dieta/farmacología , Enzimas/genética , Urea/metabolismo , Aminoimidazol Carboxamida/análogos & derivados , Aminoimidazol Carboxamida/farmacología , Animales , Células Cultivadas , Proteínas en la Dieta/administración & dosificación , Enzimas/efectos de los fármacos , Enzimas/metabolismo , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Ribonucleótidos/farmacología , Transducción de Señal/efectos de los fármacos , Transducción de Señal/genética
12.
J Hazard Mater ; 373: 152-159, 2019 07 05.
Artículo en Inglés | MEDLINE | ID: mdl-30909140

RESUMEN

The present work investigated the long-term (30 days of shock-adaptation and 60 days of restoration) impact of Cu2+, Hg2+ and Ag+ shock loading on the performance of biological wastewater treatment processes. Under the same inhibitory concentration (IC15), Cu2+ had the most significant impact on the treatment efficiency. During the shock-adaptation phase, Ag+ led to up to 4 times of biopolymers generation compared to that of the blank one; Hg2+ inhibited the nitrification process but showed little influence on other parameters; Cu2+ and Ag+ inhibited the activity of sDHA completely and decreased the content of ATP significantly, as well they caused abnormal ROS generation and corresponding CAT and SOD increment. Till 60 days of restoration can the activity of enzymes be restored to the control level, which agreed well with the results of effluent quality. Cu2+ decreased the biodiversity of the sludge to a large extent, followed by Ag+ and Hg2+. At the phylum level, Verrucomicrobia was decreased nearly to zero after 30 days of Cu2+ shock. At the genera level, Zoogloea was almost vanished after 15 days of Cu2+ shock.


Asunto(s)
Matriz Extracelular de Sustancias Poliméricas/efectos de los fármacos , Metales Pesados , Microbiota/efectos de los fármacos , Purificación del Agua , Reactores Biológicos , Enzimas/efectos de los fármacos
13.
Crit Rev Food Sci Nutr ; 59(5): 794-811, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30799633

RESUMEN

Food endogenous enzymes have impacts on color, texture and flavor of foods during food processing or preservation. Cold plasma is a novel non-thermal food processing technology, which has been extensively studied for contamination elimination and shelf life extension of foods. Particularly, much work has been reported about the effects of cold plasma on enzyme activities and alterations about enzymes conformational structures. It is thus necessary to understand the mechanisms of actions and applications of cold plasma technology in the conformation of food endogenous enzymes. This review focuses on the applications of cold plasma for the inactivation of various endogenous enzymes, including peroxidase, polyphenol oxidase, lysozyme, α-chymotrypsin, alkaline phosphatase, and pectin methylesterase. The activations of several enzymes, such as superoxide dismutase, catalase, and lipase, by cold plasma are also discussed. In addition, this review highlights the transformation of conformational structures including primary and spatial structures induced by chemical reactive species during cold plasma treatments, such as reactive oxygen species and reactive nitrogen species, especially, active sites consisting of prosthetic group and specific amino acids are demonstrated. Both extrinsic and intrinsic factors affecting cold plasma treatments are also described. In general, cold plasma exhibits the ability to activate or inactivate enzymes activities with affecting the conformational structures of enzyme. Further studies should be focused on exploration at molecular level for providing more insight on the interaction mechanism. In addition, equipment and process parameters of cold plasma operation for different fresh food products should be optimized for achieving appropriate control on enzyme variation and obtaining maximum efficiency.


Asunto(s)
Enzimas/efectos de los fármacos , Manipulación de Alimentos/métodos , Alimentos , Gases em Plasma/farmacología , Conformación Proteica/efectos de los fármacos , Catalasa/química , Catalasa/metabolismo , Catecol Oxidasa/antagonistas & inhibidores , Activación Enzimática/efectos de los fármacos , Enzimas/química , Enzimas/metabolismo , Lipasa/metabolismo , Inhibidores de la Lipooxigenasa , Lipooxigenasas , Valor Nutritivo/efectos de los fármacos , Peroxidasa/antagonistas & inhibidores , Plantas Comestibles/enzimología , Superóxido Dismutasa/química , Superóxido Dismutasa/metabolismo
14.
SLAS Discov ; 24(5): 515-522, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30811960

RESUMEN

Contemporary chemical biology and drug discovery are increasingly focused on the discovery of inhibitory molecules that interact with enzyme targets in specific ways, such as allosteric or orthosteric binding. Hence, there is increasing interest in evaluating hit compounds from high-throughput diversity screening to determine their mode of interaction with the target. In this work, the common inhibition modalities are reviewed and clarified. The impact of substrate concentration, relative to substrate KM, for each common inhibition modality is also reviewed. The pattern of changes in IC50 that accompany increasing substrate concentration are shown to be diagnostic of specific inhibition modalities. Thus, replots of IC50 as a function of the ratio [S]/KM are recommended as a simple and rapid means of assessing inhibition modality. Finally, specific recommendations are offered for ideal experimental conditions for the determination of inhibition modality through the use of IC50 replots.


Asunto(s)
Descubrimiento de Drogas , Inhibidores Enzimáticos/química , Enzimas/química , Evaluación Preclínica de Medicamentos , Enzimas/efectos de los fármacos , Ensayos Analíticos de Alto Rendimiento , Humanos , Cinética , Especificidad por Sustrato
15.
Arch Toxicol ; 93(2): 519-532, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30426164

RESUMEN

Drug-induced liver injury (DILI) constitutes one of the most frequent reasons of restricted-use warnings as well as withdrawals of drugs in postmarketing and poses an important concern for the pharmaceutical industry. The current hepatic in vivo and in vitro models for DILI detection have shown clear limitations, mainly for studies of long-term hepatotoxicity. For this reason, we here evaluated the potential of using Upcytes human hepatocytes (UHH) for repeated-dose long-term exposure to drugs. The UHH were incubated with 15 toxic and non-toxic compounds for up to 21 days using a repeated-dose approach, and, in addition to conventional examination of effects on viability, the mechanisms implicated in cell toxicity were also assessed by means of high-content screening. The UHH maintained the expression and activity levels of drug-metabolizing enzymes for up to 21 days of culture and became more sensitive to the toxic compounds after extended exposures, showing inter-donor differences which would reflect variability among the population. The assay also allowed to detect the main mechanisms implicated in the toxicity of each drug as well as identifying special susceptibilities depending on the donor. UHH can be used for a long-term repeated detection of DILI at clinically relevant concentrations and also offers key mechanistic features of drug-induced hepatotoxicity. This system is therefore a promising tool in preclinical testing of human relevance that could help to reduce and/or replace animal testing for drug adverse effects.


Asunto(s)
Técnicas de Cultivo de Célula/métodos , Enfermedad Hepática Inducida por Sustancias y Drogas/patología , Hepatocitos/efectos de los fármacos , Pruebas de Toxicidad/métodos , Adulto , Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Niño , Relación Dosis-Respuesta a Droga , Enzimas/efectos de los fármacos , Enzimas/genética , Enzimas/metabolismo , Femenino , Células Hep G2 , Hepatocitos/citología , Ensayos Analíticos de Alto Rendimiento/métodos , Humanos , Inactivación Metabólica , Persona de Mediana Edad , Factores de Tiempo
16.
Chemosphere ; 216: 69-74, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30359918

RESUMEN

Numerous studies suggested that reptiles are sensitive to environmental pollution and the abundance of many species are in decline. Our research is aim to assess the toxic effects of pesticide in reptiles. And we also want to supply some data about nondestructive samples for environmental risk assessment in reptiles. Lizards were orally administered a single-dose of beta-cypermethrin (BCP) or myclobutanil (MC) at the concentration of 20 mg/kg body weight (bw). The results showed that pesticides could induce changes in enzymatic activities (SOD, CAT, LDH, AChE) and MDA levels in organs or tissues of lizards. BCP could cause more severe oxidative damage than that of MC. Salivary enzymes activities showed sensitivity changes to the toxicity of pesticides. We could use saliva to reflect whether the reptiles are toxic by pesticides. We also agree that buccal swabs could be used as a tool for saliva sampling.


Asunto(s)
Lagartos , Nitrilos/farmacología , Plaguicidas/toxicidad , Piretrinas/farmacología , Triazoles/farmacología , Animales , Biomarcadores , Contaminación Ambiental , Enzimas/efectos de los fármacos , Nitrilos/toxicidad , Estrés Oxidativo/efectos de los fármacos , Piretrinas/toxicidad , Saliva/enzimología , Triazoles/toxicidad
17.
Expert Opin Drug Metab Toxicol ; 15(2): 167-177, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30582378

RESUMEN

INTRODUCTION: Glycyrrhizae Radix et Rhizoma (Gancao in Chinese) is the most frequently used traditional Chinese medicine (TCM) owing to its various pharmacological effects and, more importantly, the synergistic effects that enhance the efficacy and reduce the toxicity of other TCMs. Areas covered: We reviewed publications, predominantly between 1990 and 2018, that examined pharmacokinetic interactions between Gancao and other TCMs, or the bioactive constituents of these TCMs. This review focuses on the underlying mechanisms and the components responsible for the pharmacokinetic modulation by Gancao. Expert opinion: In general, the pharmacokinetic effects of Gancao are a result of its constituents such as macromolecules, like proteins, and small molecules, such as saponins and flavonoids. The mechanisms are related to formation of complexes and the influence of these on drug solubility, permeability, distribution, and metabolism. The detoxification effect of a single dose of Gancao is mainly mediated by the suppression of the intestinal absorption of toxic constituents of the co-administered TCMs and is attributable to constituents that form complexes with the toxic compounds and cause them to sediment. In contrast, the detoxification effects of repeated doses of Gancao are mediated mainly via the induction of drug metabolizing enzymes and efflux transporters.


Asunto(s)
Medicamentos Herbarios Chinos/administración & dosificación , Glycyrrhiza/química , Extractos Vegetales/administración & dosificación , Animales , Interacciones Farmacológicas , Sinergismo Farmacológico , Medicamentos Herbarios Chinos/efectos adversos , Medicamentos Herbarios Chinos/farmacología , Enzimas/efectos de los fármacos , Enzimas/metabolismo , Humanos , Absorción Intestinal , Medicina Tradicional China/efectos adversos , Medicina Tradicional China/métodos , Proteínas de Transporte de Membrana/efectos de los fármacos , Proteínas de Transporte de Membrana/metabolismo , Extractos Vegetales/efectos adversos , Extractos Vegetales/farmacología
18.
Biomed Res Int ; 2018: 5704016, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30175134

RESUMEN

OBJECTIVE: To quantitatively assess the influence of reducing agents on biological macromolecules and on the possible repair of oxidative damage. METHODS: Samples (antibody, enzyme, DNA, and diluted serum) were treated with reducing agents (ammonium ferrous sulfate, ascorbic acid, potassium iodide, and sodium hyposulfite) in the experimental group and with NaCl in the control group. Enzyme-linked immunosorbent assay and quantitative PCR were used to determine the activity of antibody, enzyme, and DNA. Native gel electrophoresis (Native-PAGE) and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) were used to determine protein structure. Reducing agents that had no inhibitory effect on biological macromolecules were selected. Antibodies were treated with oxidants to caused oxidative damage and then treated with reducing agents, and the possible repair of oxidative damage was assessed. RESULTS: Certain concentrations of ammonium ferrous sulfate resulted in significant inhibition of antibody, enzyme, DNA, and diluted serum. Certain concentrations of ascorbic acid resulted in significant inhibition of antibody. Sodium hyposulfite and potassium iodide had no effect on antibody, enzyme, DNA, and diluted serum. The OD values in group A (in which HBsAb was treated by oxidation and then a reductant) were significantly higher than those in group B (HBsAb treated by oxidation). CONCLUSION: Ammonium ferrous sulfate, ascorbic acid, sodium hyposulfite, and potassium iodide had different effects on antibody, enzyme, DNA, and diluted serum. The reduction in antibody activity due to an oxidant was partially repaired by a reductant.


Asunto(s)
Estrés Oxidativo , Sustancias Reductoras/farmacología , Anticuerpos/efectos de los fármacos , ADN/efectos de los fármacos , Electroforesis en Gel de Poliacrilamida , Enzimas/efectos de los fármacos , Oxidantes , Oxidación-Reducción
19.
Biomed Pharmacother ; 107: 1473-1479, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30257364

RESUMEN

This study sought to compare the effects of quercetin and rutin on some enzymes linked to erectile function as well as antioxidant status in penile tissue of paroxetine - induced erectile dysfunction in rats. Animals were randomly divided into twelve groups: normal control (NC), sildenafil (SD), quercetin (QA) (25 and 50 mg/kg), rutin (RU) (25 and 50 mg/kg), PAR (10 mg/kg); PAR + SD; PAR + QA, PAR + RU (25 and 50 mg/kg). After 14 days' treatment, phosphodiesterase-5' (PDE-5'), arginase, adenosine deaminase (ADA), acetylcholinesterase (AChE) and angiotensin-I converting enzyme (ACE) activities as well as malondialdehyde (MDA) and non-protein thiol levels were determined in rat penile tissues. Elevated levels of PDE-5', arginase, AChE, ADA and ACE activities and MDA were observed in PAR-induced rats with concomitant decrease in non-protein thiol levels when compared to the NC group. However, treatment with SD, QA and RU significantly reduced the activities of AChE, PDE-5', arginase, ADA and ACE and MDA levels and elevated non-protein thiol levels in penile tissues of PAR-induced rats. Furthermore, administration of QA and RU in PAR-induced rats modulated the key enzymes relevant to erection, improved antioxidant status and could be potential functional food ingredients and nutraceuticals in the prevention and/or management of erectile dysfunction.


Asunto(s)
Antioxidantes/farmacología , Disfunción Eréctil/tratamiento farmacológico , Quercetina/farmacología , Rutina/farmacología , Animales , Antioxidantes/metabolismo , Modelos Animales de Enfermedad , Enzimas/efectos de los fármacos , Enzimas/metabolismo , Disfunción Eréctil/enzimología , Disfunción Eréctil/patología , Masculino , Malondialdehído/metabolismo , Paroxetina/toxicidad , Erección Peniana/efectos de los fármacos , Ratas , Citrato de Sildenafil/farmacología
20.
Chemosphere ; 212: 245-253, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30145416

RESUMEN

Cyperus alternifolius based mesocosm-scale constructed wetland was employed to remove pharmaceuticals. We investigated the microbial community composition using phosphor lipid fatty acids (PFLAs) analysis and substrate enzyme activity during long-term exposure to pharmaceuticals in mesocosm-scale constructed wetlands. The results showed that there was no visible inhibition effect of pharmaceuticals on CW substrate enzymes activities in the experimental range (0-500 µg/L). Microbial communities, as revealed by PFLAs, were enhanced by the presence of plants, while the PFLAs content was highest when the pharmaceutical concentration was 10 µg/L or 30 µg/L at CWs. Except for anaerobic bacteria and Saturated fatty acids, the maximum PLFAs levels were reached when the pharmaceuticals were 10 µg/L or 30 µg/L, while Bacteria, G (-), fungal bacteria, Aerobic bacteria and Monounsaturated fatty acids were remarkably affected by high pharmaceuticals (100-500 µg/L). However, the main microbial florae were not changed among the treatments. In this study, the removal efficiencies of the studied pharmaceuticals in Planted (30) was greatest, which could be attributed to the higher microbial biomass. These results indicate that C. alternifolius can phytoremediate pharmaceutical-contaminated waters in CWs. Individual fatty acid cannot be used to represent specific species; therefore, more approaches to species identification such as rRNA-based methods must be included in future studies to better understand the metabolic mechanisms of microorganisms involved in the removal of studied pharmaceuticals and improve the performance of CWs.


Asunto(s)
Bacterias/metabolismo , Cyperus/metabolismo , Enzimas/metabolismo , Preparaciones Farmacéuticas/metabolismo , Suelo/química , Contaminantes Químicos del Agua/farmacocinética , Humedales , Bacterias/efectos de los fármacos , Biodegradación Ambiental , Biomasa , Cyperus/efectos de los fármacos , Enzimas/efectos de los fármacos , Ácidos Grasos/metabolismo , Eliminación de Residuos Líquidos/métodos , Contaminantes Químicos del Agua/toxicidad
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