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1.
Biomed Pharmacother ; 133: 111052, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33378958

RESUMO

The irrational use of medications has increased the incidence of microbial infections, which are a major threat to public health. Moreover, conventional therapeutic strategies are starting to become ineffective to treat these infections. Hence, there is a need to develop and characterize novel antimicrobial compounds. Phytochemicals are emerging as a safe and accessible alternative to conventional therapeutics for treating infectious diseases. Curcumin is extracted from the dried rhizome of the spice turmeric (Curcuma longa (Zingiberaceae)). However, the bioavailability of curcumin is low owing to its lipophilic property and thus has a low therapeutic efficacy in the host. A previous study synthesized structural variants of curcumin, which are called monocurcuminoids (CNs). CNs are synthesized based on the chemical structure of curcumin with only one methyl bridge. The biological activities of four previously synthesized CNs (CN59, CN63, CN67, and CN77), curcumin, and turmeric powder were examined in this study. Gas chromatography-tandem mass spectrometry analysis of curcumin and turmeric powder revealed similar peaks, which indicated the presence of curcumin in turmeric powder. The antioxidant activity of the test compounds was evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) assays. The ABTS radical scavenging activities of the test compounds were similar to those of vitamin C. The minimum inhibitory concentration (MIC) values of the test compounds against seven microbial strains were in the range of 4.06-150 µg/mL. The MIC value was equal to minimum bactericidal concentration value for CN63 (150 µg/mL) and CN67 (120 µg/mL) against Staphylococcus aureus. The treatment combination of CN77 (8.75 or 4.37 µg/mL) and turmeric powder (9.37 or 4.68 µg/mL) exerted synergistic growth-inhibiting effects on Aeromonas hydrophila, Candida albicans, and Pseudomonas aeruginosa. Photodynamic therapy using 2X MIC of CN59 decreased the growth of Enterococcus faecalis by 4.18-fold compared to the control group and completely inhibited the growth of Escherichia coli. The results of the hemolytic assay revealed that the test compounds were not cytotoxic with half-maximal inhibitory concentration values ranging from 49.65-130.9 µM. The anticoagulant activity of most compounds was comparable to that of warfarin but higher than that of heparin. This indicated that these compounds target the intrinsic coagulation pathway. These results demonstrated that these CNs are a safe and promising alternative for curcumin.


Assuntos
Anti-Infecciosos/farmacologia , Antioxidantes/farmacologia , Bactérias/efeitos dos fármacos , Bioprospecção , Candida albicans/efeitos dos fármacos , Diarileptanoides/farmacologia , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia , Animais , Anti-Infecciosos/síntese química , Anti-Infecciosos/toxicidade , Antioxidantes/síntese química , Antioxidantes/toxicidade , Bactérias/crescimento & desenvolvimento , Benzotiazóis/química , Compostos de Bifenilo/química , Coagulação Sanguínea/efeitos dos fármacos , Candida albicans/crescimento & desenvolvimento , Diarileptanoides/síntese química , Diarileptanoides/toxicidade , Resistência Microbiana a Medicamentos , Hemólise/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Fármacos Fotossensibilizantes/síntese química , Fármacos Fotossensibilizantes/toxicidade , Picratos/química , Carneiro Doméstico , Ácidos Sulfônicos/química
2.
Sci Total Environ ; : 143794, 2020 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-33272603

RESUMO

Viticulture plays an important role in generating income for small farms globally. Historically, vineyards use large quantities of phytosanitary products, such as Bordeaux mixture [Ca(OH)2 + CuSO4], to control plant diseases. These products result in the accumulation of copper (Cu) in the soil and increases the risk of transfer to water bodies. Thus, it is important to evaluate whether the presence of Cu-bearing particles in water is toxic to aquatic fauna. This study conducted chemical, mineralogical, and particle size evaluations on water samples and sediments collected from a watershed predominantly cultivated with old vineyards. The proportion of Cu-rich nanoparticles (<10 nm) in the sediment was ~27%. We exposed zebrafish to different dilutions of water and sediment samples that collected directly from the study site (downstream river) under laboratory conditions. Then, we evaluated their exploratory behavior and the stress-related endocrine parameter, whole-body cortisol. We also carried out two experiments in which zebrafish were exposed to Cu. First, we determined the median lethal concentration (LC50-96 h) of Cu and then assessed whether Cu exposure results in effects similar to those associated with exposure to the water and sediment samples collected from the study site. The water and sediment samples directly impacted the exploratory behavior of zebrafish, showing clear anxiety-like behavioral phenotype and stress in terms of cortisol increase (during the second rain event). The Cu exposure did not mimic the same behavioral changes triggered by the water and sediment samples, although it had caused similar stress in the fish. Our results highlight that even at low concentrations, the water and sediment samples from vineyard watershed runoff were able to induce behavioral and endocrine changes that may harm the ecological balance of an aquatic environment.

3.
Eur J Pharm Sci ; 151: 105397, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32485345

RESUMO

The development of cognitive impairment may be related to high levels of plasma cholesterol and obesity. Simvastatin (SV) and lovastatin (LV) are drugs that can potentially be used for the treatment of cognitive deficit. This study aimed to develop and characterize lipid-core nanocapsules (LNC) containing SV (SV-LNC) or LV (LV-LNC), evaluating the effects of SV-LNC in an animal model of cognitive deficit. The formulations SV-LNC and LV-LNC presented a particle average size around 200 nm, a low-polydispersity index, and negative zeta potential. Analysis of differential scanning calorimetry, Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy showed that there is no reaction among LNC components: LV was crystallized in the suspensions, and SV was molecularly dispersed. The encapsulation efficiency of the SV was high (98.9 ± 1.4%), while that of the LV was low (21.5 ± 1.5%).Based on these results, SV-LNC was used in the preclinical studies. Animals fed with a hyperlipidic diet (HD) developed obesity, hypercholesterolemia, and cognitive impairment, which was corroborated by the brain lesions indicated by histological analysis of some of the animals that received the high-fat diet. We observed that free simvastatin (CS3) was able to reduce the enzymatic activity of pyruvate kinase, an important enzyme for brain energy homeostasis, without affecting the memory of the animals that received a standard diet. However, it failed to improve the cognitive damage caused by a diet high in cholesterol and saturated fats. On the other hand, when simvastatin is "camouflaged" in the lipid-core nanocapsules (HNS3), this cognitive impairment improves. Thus, SV-LNC is a promising alternative therapy for the treatment of cognitive impairment.

4.
Int J Dev Neurosci ; 2020 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-32379904

RESUMO

Maple Syrup Urine Disease (MSUD) is caused by a severe deficiency in the branched-chain ketoacid dehydrogenase complex activity. Patients MSUD accumulate the branched-chain amino acids leucine (Leu), isoleucine, valine in blood, and other tissues. Leu and/or their branched-chain α-keto acids are linked to neurological damage in MSUD. When immediately diagnosed and treated, patients develop normally. Inflammation in MSUD can elicit a metabolic decompensation crisis. There are few cases of pregnancy in MSUD women, and little is known about the effect of maternal hyperleucinemia on the neurodevelopment of their babies. During pregnancy, some intercurrences like maternal infection or inflammation may affect fetal development and are linked to neurologic diseases. Lipopolysaccharide is widely accepted as a model of maternal inflammation. We analyzed the effects of maternal hyperleucinemia and inflammation and the possible positive impact the use of ibuprofen in Wistar rats on a battery of physics (ear unfolding, hair growing, incisors eruption, eye-opening, and auditive channel opening) and neurological reflexes (palmar grasp, surface righting, negative geotaxis, air-righting, and auditory-startle response) maturation parameters in the offspring. Maternal hyperleucinemia and inflammation delayed some physical parameters and neurological reflexes, indicating that both situations may be harmful to fetuses, and ibuprofen reversed some settings.

5.
Drug Chem Toxicol ; : 1-8, 2020 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-32106715

RESUMO

Inhalation of xenobiotics during manufacture process in chrome plating bath produce hazards to workers' health. Chromium (Cr) is a metal widely used by industry, and its hexavalent (VI) form has been classified as mutagenic and carcinogenic. This study aimed to evaluate the occupational risk of exposure to metals in chrome plating workers. Biological monitoring was performed through quantification of Cr, Pb, As, Ni, and V in blood by ICP-MS in 50 male chrome-plating workers from the exposed group and 50 male non-exposed workers. The inflammatory parameters assessed were ß-2 integrin, intercellular adhesion molecule-1 (ICAM-1), and L-selectin expression in lymphocytes. The genotoxicity was evaluated with comet and micronucleus (MN) assays and as a biomarker of oxidative damage the lipid peroxidation (MDA) and protein carbonyl (PCO). The results demonstrated that Cr levels in blood and urine were increased in the exposed group compared to the non-exposed group. Although the biomarkers of exposure proved to be within the levels considered safe in exposed individuals, chrome plating workers presented significantly increase in the percentage of lymphocytes expressing ß-2 integrin, ICAM-1, and L-selectin as well as DNA damage (comet assay) and plasmatic MDA and PCO levels. Therefore, it is possible also assign the injuries caused to lipids, proteins, and DNA assessed due to the increased presence of other metals such as Pb, As, Ni, and V in exposed subjects. These results suggest that exposure to xenobiotics present in the occupational environment in chrome plating industry could play a crucial role toward the inflammation, genetic, and oxidative damage.

6.
Toxicol In Vitro ; 61: 104598, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31299314

RESUMO

Nanotechnology has been an important tool for the production of nanoparticles with controlled release of drugs for therapeutic applications. Here, we produced solid lipid nanoparticles (SLN) loaded with curcumin and capsaicin (NCC) following the overarching goals of green chemistry. Currently, besides evaluating the composition, and size of these, it is necessary to understand the interactions between nanoparticles and the biomolecules present in the biological medium. For this, assays were conducted in order to evaluate the potential formation of the protein 'corona', and to better understand the results obtained in vitro, we also performed an interaction study, in silico, between the NCC components and the main serum protein, albumin. In the first hour of contact between the NCC and the culture medium showed fluctuation in the diameter of the NCC. However, after 24 and 48 h of the incubation period, all NCC concentrations showed an increase in size, which can be attributed to plasma protein adsorption. Since, hard corona takes a few seconds, while the soft corona can be formed in minutes up to a few hours. On the other hand, best docking binding-poses of interaction for the formed docking complexes evaluated suggest interactions following the docking affinity like free energy FEB (Tween 80-bovine serum albumin) ≈ FEB (Span 80-bovine serum albumin) showing a pharmacodynamic pattern based in non-covalent hydrophobic interactions with the bovine serum albumin binding-site. Our in silico results clarify and reinforce our in vitro findings of corona formation, which represents the real interaction with cell membranes in vivo.


Assuntos
Capsaicina/química , Curcumina/química , Nanopartículas/química , Coroa de Proteína/química , Soroalbumina Bovina/química , Gorduras na Dieta , Simulação de Acoplamento Molecular
7.
Microb Pathog ; 110: 694-702, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28159662

RESUMO

Pelargonium graveolens is a member of the Geraniaceae family and has been used in folk medicine in many countries because of its anti-inflammatory activity. No studies have yet been reported to evaluate the anti-inflammatory activity of a nanoemulsion containing geranium oil (GO) model in macrophages. In this study the anti-inflammatory effect of Geranium nanoemulsion (NEG) macrophages induced with soluble proteins of Candida albicans was investigated. GO presented citronellol (17.74%) and geraniol (14.43%) as main constituents. The characterization in NEG was demonstrated, showing the particle size of 164 ± 3.5 nm, PDI of 0.12 ± 0.006 and zeta potential -10 mV ± 1.7. The MIC obtained for NEG and GO were 3.64 µg ml-1 and 1.82 µg ml-1, respectively. The viability of the macrophages treated with NEG and GO concentrations (1/2 x, 1x and 2x MIC) was evaluated. There was a significant reduction of viability and the MTT assay was not confirmed after the LDH assay. Anti-inflammatory activity was evaluated by determining nitric oxide (NO), cytokines (interleukin IL-1, IL-6 and IL-10), tumor necrosis factor-α (TNF) and the expression levels gene of interleukin (IL-2), cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). The apoptosis inhibition capacity was assessed by determination of INFγ, caspase 3 and caspase 8. The results indicated that there was a significant increase of NO in the levels after treatment with NEG and significantly reduced levels after treatment with GO. The cytokines (IL-1, IL-6, IL-10, and TNF) were evaluated and NEG (½ x, 1x MIC) decreased IL-1 levels by 1.25-1.37 times, respectively. The NEG did not decrease IL-6 levels and a significant increase was observed for IL-10. GO significantly decreased IL-6 and IL-10 levels. There was a significant decrease in IL-2 and COX-2 levels and increased levels of iNOs. The levels of IFNγ and caspase-3 after treatment with NEG decreased indicating an anti-inflammatory effect and can inhibit apoptosis. Finally, the levels of caspase-8 do not change. Thus, pretreatment with NEG induced an anti-inflammatory effect against soluble proteins of C. albicans model macrophages.


Assuntos
Anti-Inflamatórios/farmacologia , Antígenos de Fungos/imunologia , Candida albicans/química , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Óleos Voláteis/farmacologia , Pelargonium/química , Monoterpenos Acíclicos , Animais , Anti-Inflamatórios/isolamento & purificação , Antígenos de Fungos/isolamento & purificação , Sobrevivência Celular/efeitos dos fármacos , Citocinas/metabolismo , Emulsões/farmacologia , Macrófagos/fisiologia , Camundongos , Monoterpenos/análise , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Óleos Voláteis/química , Óleos Voláteis/isolamento & purificação , Prostaglandina-Endoperóxido Sintases/metabolismo , Células RAW 264.7 , Terpenos/análise
8.
Exp Parasitol ; 149: 39-46, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25499512

RESUMO

This study aimed to verify the effect of the treatment with A. satureioides essential oil (free and nanoencapsulated forms) and diminazene aceturate on hematological and biochemical variables in rats infected by Trypanosoma evansi. The 56 rats were divided into seven groups with eight rats each. Groups A, C and D were composed by uninfected animals, and groups B, E, F and G were formed by infected rats with T. evansi. Rats from groups A and B were used as negative and positive control, respectively. Rats from the groups C and E were treated with A. satureioides essential oil, and groups D and F were treated with A. satureioides nanoencapsulated essential oil. Groups C, D, E and F received one dose of oil (1.5 mL kg(-1)) during five consecutive days orally. Group G was treated with diminazene aceturate (D.A.) in therapeutic dose (3.5 mg kg(-1)) in an only dose. The blood samples were collected on day 5 PI for analyses of hematological (erythrocytes and leukocytes count, hemoglobin concentration, hematocrit, mean corpuscular and mean corpuscular hemoglobin concentration) and biochemical (glucose, triglycerides, cholesterol, alanine aminotransferase (ALT), aspartate aminotransferase (AST), albumin, urea and creatinine) variables. A. satureioides administered was able to maintain low parasitemia, mainly the nanoencapsulated form, on 5 days post infection. On the infected animals with T. evansi treated with A. satureioides essential oil (free and nanocapsules) the number of total leucocytes, lymphocytes and monocytes present was similar to uninfected rats, and different from infected and not-treated animals (leukocytosis). Treatment with A. satureioides in free form elevated levels of ALT and AST, demonstrating liver damage; however, treatment with nanoencapsulated form did not cause elevation of these enzymes. Finally, treatments inhibited the increase in creatinine levels caused by infection for T. evansi. In summary, the nanoencapsulated form showed better activity on the trypanosome; it did not cause liver toxicity and prevented renal damage.


Assuntos
Achyrocline/química , Diminazena/análogos & derivados , Óleos Voláteis/uso terapêutico , Óleos Vegetais/uso terapêutico , Tripanossomicidas/uso terapêutico , Tripanossomíase/tratamento farmacológico , Animais , Biomarcadores/sangue , Análise Química do Sangue , Diminazena/administração & dosagem , Diminazena/uso terapêutico , Cães , Feminino , Testes Hematológicos , Rim/fisiologia , Fígado/fisiologia , Nanocápsulas , Óleos Voláteis/administração & dosagem , Óleos Voláteis/química , Parasitemia/parasitologia , Óleos Vegetais/administração & dosagem , Óleos Vegetais/química , Ratos , Ratos Wistar , Tripanossomicidas/administração & dosagem , Trypanosoma/efeitos dos fármacos , Tripanossomíase/sangue
9.
Neurochem Res ; 38(3): 632-43, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23277415

RESUMO

Maple Syrup Urine Disease is an inborn error of metabolism caused by severe deficiency in the activity of branched-chain α-keto acid dehydrogenase complex. Neurological disorder is common in patients with maple syrup urine disease. Although leucine is considered the main toxic metabolite, the mechanisms underlying the neuropathology of brain injury are poorly understood. In the present study, we evaluated the possible preventive effect of the co-administration of creatine plus pyruvate on the effects elicited by leucine administration to female Wistar rats during pregnancy and lactation on some oxidative stress parameters as well as the activities of some enzymes involved in the phosphoryltransfer network in the brain cortex and hippocampus of the offspring at 21 days of age. Leucine administration induced oxidative stress and altered the activities of pyruvate kinase, adenylate kinase, mitochondrial and cytosolic creatine kinase. Co-administration of creatine plus pyruvate was partially effective in the prevention of some alterations provoked by leucine administration on the oxidative stress but not in the enzymes of phosphoryltransfer network. These results suggest that non-treated maternal hyperleucinemia may be toxic to the brain of the offspring.


Assuntos
Córtex Cerebral/metabolismo , Hipocampo/metabolismo , Leucina/farmacologia , Doença da Urina de Xarope de Bordo/fisiopatologia , Fosfotransferases/metabolismo , Efeitos Tardios da Exposição Pré-Natal , Animais , Antioxidantes/metabolismo , Córtex Cerebral/efeitos dos fármacos , Creatina/farmacologia , Feminino , Hipocampo/efeitos dos fármacos , Lactação/efeitos dos fármacos , Masculino , Estresse Oxidativo/efeitos dos fármacos , Gravidez , Ácido Pirúvico/farmacologia , Ratos , Ratos Wistar
10.
Metab Brain Dis ; 23(2): 221-33, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18425567

RESUMO

Despite the significant brain abnormalities, the neurotoxic mechanisms of brain injury in hypertryptophanemia are virtually unknown. In this work, we determined the thiobarbituric acid-reactive substances, 2',7'-dihydrodichlorofluorescein oxidation, reduced glutathione and the activities of catalase, superoxide dismutase and glutathione peroxidase in cerebral cortex from rats loaded with L-tryptophan. High L-tryptophan concentrations, similar to those found in hypertryptophanemic patients were induced by three subcutaneous injections of saline-buffered tryptophan (2 micromol/g body weight) to 30-day-old Wistar rats. The parameters were assessed 1 h after the last injection. It was observed that tryptophan significantly increased thiobarbituric acid-reactive substances, 2',7'-dihydrodichlorofluorescein oxidation and reduced glutathione, whereas it reduced catalase activity. Pre-treatment with taurine (1.6 micromol/g of body weight), or alpha-tocopherol plus ascorbic acid (40 and 100 microg/g body weight, respectively) prevented those effects of tryptophan, reinforcing the hypothesis that tryptophan induces oxidative stress in brain cortex of the rats. Therefore, these findings also occur in human hypertryptophanemia or in other neurodegenerative diseases in which tryptophan accumulates, then oxidative stress may be involved in the mechanisms leading to the brain injury observed in patients affected by these disorders.


Assuntos
Erros Inatos do Metabolismo dos Aminoácidos/metabolismo , Encefalopatias Metabólicas/metabolismo , Córtex Cerebral/metabolismo , Degeneração Neural/metabolismo , Estresse Oxidativo/fisiologia , Triptofano/metabolismo , Erros Inatos do Metabolismo dos Aminoácidos/induzido quimicamente , Erros Inatos do Metabolismo dos Aminoácidos/fisiopatologia , Animais , Antioxidantes/farmacologia , Encefalopatias Metabólicas/induzido quimicamente , Encefalopatias Metabólicas/fisiopatologia , Catalase/metabolismo , Morte Celular/efeitos dos fármacos , Morte Celular/fisiologia , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/fisiopatologia , Modelos Animais de Doenças , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Masculino , Degeneração Neural/induzido quimicamente , Degeneração Neural/fisiopatologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Wistar , Superóxido Dismutase/metabolismo , Superóxido Dismutase-1 , Taurina/farmacologia , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Triptofano/toxicidade , alfa-Tocoferol/farmacologia
11.
Metab Brain Dis ; 23(2): 133-45, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18418703

RESUMO

Cystinosis is a systemic genetic disease caused by a lysosomal transport deficiency accumulating cystine in the lysosomes of all tissues. Although tissue damage might depend on cystine accumulation, the mechanisms of tissue damage are still obscures. Considering that thiol-containing enzymes are critical for several metabolic pathways, our main objective was to investigate the effects of cystine or cystine dimethylester load on the thiol-containing enzymes creatine kinase and pyruvate kinase, in the brain cortex of young Wistar rats. The animals were injected twice a day with 1.6 micromol/g body weight of cystine dimethylester or 1 micromol/g body weight of cystine and/or 0.46 micromol/g body weight of cysteamine from the 16th to the 20th postpartum day and sacrificed after 12 h. Cystine or cystine dimethylester administration inhibited the two enzyme activities. Co-administration of cysteamine, the drug used to treat cystinotic patients, normalized the two enzyme activities. Lactate dehydrogenase activity, a nonthiol-containing enzyme was not affected by cystine dimethylester administration. Cystine inhibits creatine kinase and pyruvate activities possibly by oxidation of the sulfhydryl groups of the enzymes. Considering that creatine kinase and pyruvate kinase, like other thiol-containing enzymes, are crucial for energy homeostasis and antioxidant defenses, the enzymes inhibition caused by cystine released from lysosomes could be one of the mechanisms of tissue damage in patients with cystinosis.


Assuntos
Córtex Cerebral/enzimologia , Creatina Quinase/metabolismo , Cistina/metabolismo , Cistinose/enzimologia , Lisossomos/enzimologia , Piruvato Quinase/metabolismo , Animais , Antioxidantes/metabolismo , Córtex Cerebral/fisiopatologia , Cisteamina/farmacologia , Cisteamina/uso terapêutico , Cistina/análogos & derivados , Cistina/toxicidade , Cistinose/tratamento farmacológico , Cistinose/fisiopatologia , Modelos Animais de Doenças , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/uso terapêutico , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Ratos , Ratos Wistar , Compostos de Sulfidrila/metabolismo
12.
Metab Brain Dis ; 23(1): 81-93, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18030610

RESUMO

Cystinosis is a systemic genetic disease caused by a lysosomal transport deficiency accumulating cystine in most tissues. Tissue damage depends on cystine accumulation, but the mechanisms of this damage are still obscure. Cysteamine administration depletes cystine accumulated, increasing survive of affected patients. Studies performed in fibroblasts of cystinotic patients suggest that apoptosis is enhanced in this disease. Considering that oxidative stress is a known apoptosis inducer, our main objective was to investigate a possible antioxidant effect of cysteamine on several parameters of oxidative stress in the brain of young rats. Animals received three subcutaneous injections at 3-h intervals of a buffered solution (pH 7.4) of 10 mg/kg body weight cysteamine and were sacrificed 1 h after the last injection. Cysteamine decreased lipoperoxidation and glutathione peroxidase activity, and increased the carbonyl content of proteins and catalase activity. In vitro studies showed that cysteamine reduced lipoperoxidation, 2',7'-dihydrodichlorofluorescein oxidation, carbonyl content of proteins and catalase activity, and increased glutathione peroxidase activity. These results suggest that cysteamine may act as a scavenger of superoxide free radicals and hydrogen peroxide. Therefore, it is possible that cysteamine may extend life of cystinotic patients acting not only as a cystine depleting drug, but also as a free radical scavenger, reducing cell damage by apoptosis.


Assuntos
Córtex Cerebral/metabolismo , Cisteamina/farmacologia , Estresse Oxidativo/fisiologia , Animais , Catalase/metabolismo , Córtex Cerebral/efeitos dos fármacos , Fluoresceínas , Corantes Fluorescentes , Glutationa Peroxidase/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Carbonilação Proteica/efeitos dos fármacos , Ratos , Ratos Wistar , Superóxido Dismutase/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo
13.
Pediatr Nephrol ; 22(8): 1121-8, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17534668

RESUMO

Cystinosis is a systemic genetic disease caused by a lysosomal transport deficiency accumulating cystine in most tissues. Although tissue damage might depend on cystine accumulation, the mechanisms of tissue damage are not fully understood. Studies performed in fibroblasts of cystinotic patients and in kidney cells loaded with cystine dimethyl ester (CDME) suggest that apoptosis is enhanced in this disease. Considering that oxidative stress is a known apoptosis inducer, our main objective was to investigate the effects of CDME loading on several parameters of oxidative stress in the kidney of young rats. Animals were injected twice a day with 1.6 micromol/g body weight CDME and/or 0.26 micromol/g body weight cysteamine (CSH) from the 16th to the 20th postpartum day and killed after 1 or 12 h. CDME induced lipoperoxidation and protein carbonylation and stimulated superoxide dismutase, glutathione peroxidase (GPx), and catalase activities, probably through the formation of superoxide anions, hydrogen peroxide, and hydroxyl free radicals. Coadministration of CSH, the drug used to treat cystinotic patients, prevented, at least in part, those effects, possibly acting as a scavenger of free radicals. These results suggest that the induction of oxidative stress might be one of the mechanisms leading to tissue damage in cystinotic patients.


Assuntos
Cistina/análogos & derivados , Cistinose/etiologia , Rim/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Animais , Catalase/metabolismo , Cisteamina/administração & dosagem , Cisteamina/farmacologia , Cistina/administração & dosagem , Cistina/toxicidade , Cistinose/genética , Cistinose/patologia , Interações Medicamentosas , Fluoresceínas/metabolismo , Glutationa Peroxidase/metabolismo , Peróxido de Hidrogênio/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Oxirredução , Proteínas/análise , Distribuição Aleatória , Ratos , Ratos Wistar , Superóxido Dismutase/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/análise
14.
Arch Med Res ; 38(2): 164-9, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17227724

RESUMO

BACKGROUND: Cystinosis is an autosomal recessive disorder associated with lysosomal cystine accumulation caused by defective cystine efflux. Visual deficit is a possible consequence of cystine accumulation in cornea and retina. Fibroblasts from cystinotic patients present ATP deficit with intact mitochondrial energy-generating capacity by an unknown mechanism. Considering that creatine kinase is a thiol enzyme crucial for energy homeostasis in retina, and disulfides like cystine may alter thiol enzymes, the main objective of the present study was to investigate the effect of cystine and cysteamine, the drug used for treatment of cystinotic patients, on creatine kinase activity in cytosolic and mitochondrial fractions of the retina from adult pigs. METHODS: Retina was isolated from 6-month-old Landrace pigs, homogenized and mitochondrial and cytosolic fractions separated by centrifugation. Cytosolic and mitochondrial creatine kinase activities were determined in the presence of different concentrations of cystine and/or cysteamine. RESULTS: Cystine inhibited the enzyme activity in a dose- and time-dependent manner and cysteamine prevented and reversed the inhibition caused by cystine, suggesting that cystine inhibits creatine kinase activity by oxidation of the sulfhydryl groups of the enzyme. CONCLUSIONS: Considering that creatine kinase is a crucial enzyme for retina energy homeostasis, in case cystine leaves lysosome these results provide a possible mechanism for cystine toxicity and also another beneficial effect for the use of cysteamine in patients with cystinosis.


Assuntos
Creatina Quinase/antagonistas & inibidores , Cistina/toxicidade , Cistinose/enzimologia , Cistinose/etiologia , Retina/efeitos dos fármacos , Animais , Fracionamento Celular , Masculino , Retina/enzimologia , Sus scrofa
15.
Brain Res ; 1124(1): 188-96, 2006 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-17097623

RESUMO

3-hydroxykynurenine, a tryptophan metabolite, is known to be potential neurotoxic in some neurodegenerative disorders. However, the molecular mechanisms of toxicity are not well understood. Creatine kinase plays a key role in energy metabolism of tissues with intermittently high and fluctuating energy requirements, such as nervous tissue. This study investigated the in vitro effect of 3-hydroxykynurenine on creatine kinase activity in the brain cortex of rats. The results indicated that low micromolar 3-hydroxykynurenine concentrations inhibit uncompetitively mitochondrial and cytosolic creatine kinase activities in a time and dose-dependent way. Inhibition was prevented, but not reversed by incubation with reduced glutathione, dithiothreitol and ascorbic acid plus trolox, suggesting adduct formation. The assay under nitrogen atmosphere suggested that the inhibition was caused by products of 3-hydroxykynurenine autoxidation. Determination of thiol groups suggested that adducts between the enzyme and autoxidation products of 3-hydroxykynurenine were not formed with sulfhydryl groups. The interaction plot between tryptophan and 3-hydroxykynurenine suggested different sites of action on creatine kinase with cross-inhibition. Considering the importance of creatine kinase for the maintenance of energy homeostasis in the brain, it is conceivable that an alteration of this enzyme activity may be one of the mechanisms by which 3-hydroxykynurenine might be neurotoxic.


Assuntos
Córtex Cerebral/efeitos dos fármacos , Creatina Quinase/metabolismo , Cinurenina/análogos & derivados , Análise de Variância , Animais , Animais Recém-Nascidos , Córtex Cerebral/ultraestrutura , Relação Dose-Resposta a Droga , Interações Medicamentosas , Técnicas In Vitro , Cinurenina/farmacologia , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Ratos , Ratos Wistar , Compostos de Sulfidrila/metabolismo , Triptofano/metabolismo
16.
Pediatr Res ; 60(2): 190-5, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16864702

RESUMO

Nephropathic cystinosis is a lethal genetic disease caused by a lysosomal transport disorder leading to intralysosomal cystine accumulation in all tissues. Cystinosis is the most common inherited cause of Fanconi syndrome, but the mechanisms by which cystine causes tissue damage are not fully understood. Thiol-containing enzymes are critical for renal energy metabolism and may be altered by disulfides like cystine. Therefore, in the present study our main objective was to investigate the in vivo and in vitro effects of cystine on creatine kinase, which contains critical thiol groups in its structure, in the kidney of young Wistar rats. We observed that cystine inhibited in vivo and in vitro the enzyme activity and that this inhibition was prevented by cysteamine and glutathione. The results suggest oxidation of essential sulfhydryl groups necessary for creatine kinase function by cystine. Considering that creatine kinase and other thiol-containing enzymes are crucial for renal energy metabolism, and programmed cell death occurs in situations of energy deficiency, the enzyme inhibition caused by cystine released from lysosomes might be a mechanism of tissue damage in patients with cystinosis.


Assuntos
Creatina Quinase/antagonistas & inibidores , Cistina/toxicidade , Cistinose/etiologia , Rim/enzimologia , Fatores Etários , Animais , Cistinose/enzimologia , Rim/efeitos dos fármacos , Ratos , Ratos Wistar , Compostos de Sulfidrila/metabolismo
17.
Neurochem Int ; 49(1): 87-93, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16497412

RESUMO

Despite the significant brain abnormalities, the neurotoxic mechanisms of brain injury in hypertryptophanemia are virtually unknown. In this work, it was investigated the in vitro effect of l-tryptophan on various parameters of oxidative stress, namely spontaneous chemiluminescence, thiobarbituric acid-reactive substances (TBA-RS), total radical-trapping antioxidant potential (TRAP), total antioxidant reactivity (TAR) and glutathione (GSH) levels in cerebral cortex from 30-day-old rats. Tryptophan significantly increased chemiluminescence and TBA-RS measurements indicating that this amino acid induced lipid peroxidation in vitro. We also observed that tryptophan significantly decreased the brain antioxidant defenses by reducing the values of TRAP, TAR and GSH, reflecting that the overall content of antioxidants was reduced by tryptophan. Furthermore, the tryptophan-induced increase of TBA-RS was fully prevented by GSH and by combination of catalase plus superoxide dismutase, but not by the inhibitor of nitric oxide synthase N(omega)-nitro-L-arginine methyl ester (L-NAME). In case these findings also occur in human hypertryptophanemia or in other neurodegenerative diseases in which tryptophan accumulates, it is feasible that oxidative stress may be involved in the mechanism leading to the brain injury observed in patients affected by these disorders.


Assuntos
Erros Inatos do Metabolismo dos Aminoácidos/metabolismo , Córtex Cerebral/metabolismo , Degeneração Neural/metabolismo , Estresse Oxidativo/fisiologia , Triptofano/metabolismo , Erros Inatos do Metabolismo dos Aminoácidos/fisiopatologia , Animais , Antioxidantes/metabolismo , Catalase/metabolismo , Catalase/farmacologia , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/fisiopatologia , Modelos Animais de Doenças , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/fisiologia , Inibidores Enzimáticos/farmacologia , Radicais Livres/metabolismo , Glutationa/metabolismo , Glutationa/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Peroxidação de Lipídeos/fisiologia , Luminescência , Masculino , NG-Nitroarginina Metil Éster/farmacologia , Degeneração Neural/induzido quimicamente , Degeneração Neural/fisiopatologia , Óxido Nítrico Sintase Tipo I/antagonistas & inibidores , Óxido Nítrico Sintase Tipo I/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Wistar , Superóxido Dismutase/metabolismo , Superóxido Dismutase/farmacologia , Substâncias Reativas com Ácido Tiobarbitúrico/análise , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Triptofano/toxicidade
18.
Neurochem Res ; 27(9): 947-52, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12396106

RESUMO

The mechanisms by which phenylalanine is toxic to the brain in phenylketonuria are not fully understood. Considering that brain glucose metabolism is reduced in these patients, our main objective was to determine pyruvate kinase activity in brain cortex of rats subjected to acute and chronic chemically induced hyperphenylalaninemia. The effect of alanine administration on the enzyme activity in the treated rats was also investigated. We also studied the in vitro effect of the two amino acids on pyruvate kinase activity in brain cortex of nontreated rats. The results indicated that phenylalanine inhibits pyruvate kinase in vitro and in vivo and that alanine prevents the inhibitory effect of phenylalanine on the enzyme activity. Considering the crucial role pyruvate kinase plays in glucose metabolism in brain, it is possible that inhibition of this enzyme activity may contribute to the brain damage characteristic of this disease.


Assuntos
Alanina/farmacologia , Córtex Cerebral/efeitos dos fármacos , Fenilalanina/sangue , Piruvato Quinase/metabolismo , Animais , Córtex Cerebral/enzimologia , Ratos , Ratos Wistar
19.
Neurochem Res ; 27(5): 353-7, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-12064349

RESUMO

Phenylketonuria (PKU) is biochemically characterized by the accumulation of phenylalanine (Phe) and its metabolites in tissues of affected children. Neurological damage is the clinical hallmark of PKU, and Phe is considered the main neurotoxic metabolite in this disorder. However, the mechanisms of neurotoxicity are poorly known. The main objective of the present work was to measure the activities of the mitochondrial respiratory chain complexes (RCC) and succinate dehydrogenase (SDH) in brain cortex of Wistar rats subjected to chemically induced hyperphenylalaninemia (HPA). We also investigated the in vitro effect of Phe on SDH and RCC activities in the cerebral cortex of 22-day-old rats. HPA was induced by subcutaneous administration of 2.4 micromol/g body weight alpha-methylphenylalanine, a phenylalanine hydroxylase inhibitor, once a day, plus 5.2 microM/g body weight phenylalanine, twice a day, from the 6th-21st postnatal day. The results showed a reduction of SDH and complex I + III activity in brain cortex of rats subjected to HPA. We also verified that Phe inhibited the in vitro activity of complexes I + III, possibly by competition with NADH. Considering the importance of SDH and RCC for the maintenance of energy supply to brain, our results suggest that energy deficit may contribute to the Phe neurotoxicity in PKU.


Assuntos
Córtex Cerebral/efeitos dos fármacos , Transporte de Elétrons/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Fenilalanina/farmacologia , Animais , Córtex Cerebral/metabolismo , Mitocôndrias/metabolismo , Fenilcetonúrias/metabolismo , Ratos , Ratos Wistar
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