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1.
PLoS One ; 17(8): e0272776, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35947632

RESUMO

Hepatocellular carcinoma (HCC) is one of the world's most risky diseases due to the lack of clear and cost-effective therapeutic targets. Currently, the toxicity of conventional chemotherapeutic medications and the development of multidrug resistance is driving research into targeted therapies. The nano-biomedical field's potential for developing an effective therapeutic nano-sized drug delivery system is viewed as a significant pharmaceutical trend for the encapsulation and release of numerous anticancer therapies. In this regard, current research is centered on the creation of biodegradable chitosan nanoparticles (CSNPs) for the selective and sustained release of bee venom into liver cancer cells. Furthermore, surface modification with polyethylene glycol (PEG) and GE11 peptide-conjugated bee venom-CSNPs allows for the targeting of EGFR-overexpressed liver cancer cells. A series of in vitro and in vivo cellular analyses were used to investigate the antitumor effects and mechanisms of targeted bee venom-CSNPs. Targeted bee venom-CSNPs, in particular, were found to have higher cytotoxicity against HepG2 cells than SMMC-7721 cells, as well as stronger cellular uptake and a substantial reduction in cell migration, leading to improved cancer suppression. It also promotes cancer cell death in EGFR overexpressed HepG2 cells by boosting reactive oxygen species, activating mitochondria-dependent pathways, inhibiting EGFR-stimulated MEK/ERK pathway, and elevating p38-MAPK in comparison to native bee venom. In hepatocellular carcinoma (HCC)-induced mice, it has anti-cancer properties against tumor tissue. It also improved liver function and architecture without causing any noticeable toxic side effects, as well as inhibiting tumor growth by activating the apoptotic pathway. The design of this cancer-targeted nanoparticle establishes GE11-bee venom-CSNPs as a potential chemotherapeutic treatment for EGFR over-expressed malignancies. Finally, our work elucidates the molecular mechanism underlying the anticancer selectivity of targeted bee venom-CSNPs and outlines therapeutic strategies to target liver cancer.


Assuntos
Venenos de Abelha , Carcinoma Hepatocelular , Quitosana , Neoplasias Hepáticas , Nanopartículas , Animais , Venenos de Abelha/farmacologia , Venenos de Abelha/uso terapêutico , Carcinoma Hepatocelular/patologia , Quitosana/uso terapêutico , Receptores ErbB/metabolismo , Neoplasias Hepáticas/patologia , Sistema de Sinalização das MAP Quinases , Camundongos , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Peptídeos/metabolismo
2.
Eur J Nutr ; 61(8): 4091-4105, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35804266

RESUMO

PURPOSE: Vitamin A is an essential nutrient with vital biological functions. The present study investigated the effect of different doses of vitamin A palmitate at different time intervals on thyroid hormones and glycemic markers. METHODS: Male rats were administrated vitamin A palmitate at different doses (0, 0.7, 1.5, 3, 6, and 12 mg/kg, oral) and samples were collected at different time intervals of 2, 4, and 6 weeks. The levels of vitamin A, thyroid hormones (T3, T4, and TSH), deiodinases (Dio1 and Dio3), glycemic markers (blood insulin and fasting glucose levels, HOMA IR and HOMA ß), retinol-binding protein 4 (RBP4) and the gluconeogenic enzyme phosphoenolpyruvate carboxykinase (PEPCK) were measured. RESULTS: The findings demonstrated that long-term supplementation with high doses of vitamin A palmitate resulted in hypothyroidism (lower T3 and T4 levels and elevated TSH levels) as well as upregulation of Dio1 and Dio3 expression levels. This effect was associated with elevated glucose and insulin levels, enhanced HOMA IR, and decreased HOMA B index. In addition, prolonged vitamin A supplementation significantly increased RBP4 levels that upregulated the expression of PEPCK. CONCLUSION: High doses of vitamin A supplementation increased the risk of hypothyroidism, modulated insulin sensitivity, and over a long period, increased the incidence of type 2 diabetes mellitus associated with oxidative stress and hepatitis.


Assuntos
Diabetes Mellitus Tipo 2 , Hipotireoidismo , Resistência à Insulina , Insulinas , Masculino , Ratos , Animais , Resistência à Insulina/fisiologia , Ratos Wistar , Vitamina A , Iodeto Peroxidase , Fosfoenolpiruvato , Diabetes Mellitus Tipo 2/metabolismo , Glicemia/metabolismo , Glucose , Hormônios Tireóideos , Tireotropina , Suplementos Nutricionais , Insulina
3.
Sci Rep ; 11(1): 252, 2021 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-33420282

RESUMO

Lead (Pb) toxicity is one of the most prevalent causes of human neurotoxicity. The available chelator drugs used now have many adverse effects. So, in this study, the protective role of Beta vulgaris juice (BVJ) on rat neurotoxicity induced by Pb was evaluated and the results were compared with the results of dimercaptosuccinic acid (DMSA, as used drug). Additionally, the synergistic effect of BVJ and DMSA against Pb-induced neurotoxicity was assessed. The study focused on the determination of the antioxidant, anti-inflammatory, and neurological potential of BVJ (alone, and with DMSA) towards lead-induced neurotoxicity. Also, the characterization of BVJ was studied. The results showed that BVJ contains considerable quantities of polyphenols, triterpenoids, and betalains which play an important role as antioxidants and anti-inflammatory. BVJ exhibited a protective effect against neurotoxicity via the reduction of Pb levels in blood and brain. Moreover, BVJ decreased the oxidative stress, inflammation, and cell death induced by Pb. Also, BVJ regulated the activities of acetylcholine esterase and monoamine oxidase-A which changed by Pb toxicity. BVJ and DMSA combination displayed a synergistic antineurotoxic effect (combination index ˂ 1). These results were in harmony with brain histopathology. Conclusion: BVJ has a powerful efficacy in the protection from brain toxicity via diminishing Pb in the brain and blood circulation, resulting in the prevention of the oxidative and inflammatory stress. Treatment with BVJ in combination with DMSA revealed a synergistic effect in the reduction of neurotoxicity induced by Pb. Also, the antioxidant and anti-inflammatory effects of the BVJ lead to the improvement of DMSA therapy.


Assuntos
Antioxidantes/uso terapêutico , Beta vulgaris/química , Fármacos Neuroprotetores/uso terapêutico , Síndromes Neurotóxicas/tratamento farmacológico , Extratos Vegetais/uso terapêutico , Succímero/uso terapêutico , Animais , Antioxidantes/farmacologia , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Fragmentação do DNA/efeitos dos fármacos , Sinergismo Farmacológico , Inflamação/tratamento farmacológico , Chumbo/sangue , Chumbo/toxicidade , Masculino , Fármacos Neuroprotetores/farmacologia , Síndromes Neurotóxicas/etiologia , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/farmacologia , Ratos , Succímero/farmacologia
4.
BMC Complement Med Ther ; 20(1): 268, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32873301

RESUMO

BACKGROUND: Lead (Pb) is observed in all areas of the environment, mainly derived from human operations such as mining, processing, and burning fossil fuels. Pb toxicity is one of the most prevalent causes of human hepatotoxicity. The available chelator drugs used now have many adverse effects and therefore the world is looking for natural and secure alternatives. METHODS: Here, we evaluated the hepatoprotective role of the oral administration (1 g/kg b.w.) of the lyophilized Beta vulgaris juice (BVJ) against Pb-induced rat hepatotoxicity. We also examined the possible synergistic hepatoprotective impact of the combination between BVJ and 2,3- dimercaptosuccinic acid (DMSA, the currently approved drug for Pb-toxicity). The evaluation depends on the ability of BVJ, DMSA, or their combination (BVJ-DMSA) to reduce serum and hepatic Pb level and to avoid oxidative stress and inflammation caused by Pb. The level of lipid peroxidation, reduced glutathione (GSH), total antioxidant capacity, and the activity of the antioxidant enzymes were quantified. In addition, the level of interleukin (IL)-6, nitric oxide (NO), DNA fragmentation, and liver histology were studied. RESULTS: The results showed that BVJ contained considerable amounts of betalains, vitamin C, and various types of phenolic compounds. Therefore, BVJ displayed a significant (p < 0.05) preventive influence on the elevation of Pb levels in blood and liver as well as the hepatic DNA fragmentation. In addition, it significantly (p < 0.05) improved most of the studied antioxidant and inflammatory markers in the Pb-intoxicated rats. However, the combined extract (BVJ-DMSA) revealed synergistic (combination index < 1) activities in most of the tested parameters. The histopathological results verified the biochemical findings of this research. CONCLUSION: BVJ has a potent efficiency in the protection from Pb-induced hepatotoxicity through the reduction of its accumulation in blood and liver and the prevention of the oxidative stress and inflammation induced by Pb. Additionally, the treatment of hepatotoxicity with BVJ and DMSA in combination showed a synergistic effect and reduced the adverse effects induced by DMSA. Thus, BVJ can be a promising hepatoprotective extract against lead toxicity and its combination with DMSA potentiates this effect.


Assuntos
Beta vulgaris , Sinergismo Farmacológico , Inflamação/tratamento farmacológico , Intoxicação por Chumbo/tratamento farmacológico , Fígado/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Succímero/farmacologia , Administração Oral , Animais , Antioxidantes/farmacologia , Quelantes/farmacologia , Modelos Animais de Doenças , Egito , Sucos de Frutas e Vegetais , Chumbo/sangue , Masculino , Ratos
5.
PLoS One ; 10(12): e0144509, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26659465

RESUMO

The present study aims to investigate the hepatoprotective effect of taurine (TAU) alone or in combination with silymarin (SIL) on CCl4-induced liver damage. Twenty five male rats were randomized into 5 groups: normal control (vehicle treated), toxin control (CCl4 treated), CCl4+TAU, CCl4+SIL and CCl4+TAU+SIL. CCl4 provoked significant increases in the levels of hepatic TBARS, NO and NOS compared to control group, but the levels of endogenous antioxidants such as SOD, GPx, GR, GST and GSH were significantly decreased. Serum pro-inflammatory and fibrogenic cytokines including TNF-α, TGF-ß1, IL-6, leptin and resistin were increased while the anti-inflammatory (adiponectin) cytokine was decreased in all treated rats. Our results also showed that CCl4 induced an increase in liver injury parameters like serum ALT, AST, ALP, GGT and bilirubin. In addition, a significant increase in liver tissue hydroxyproline (a major component of collagen) was detected in rats exposed to CCl4. Moreover, the concentrations of serum TG, TC, HDL-C, LDL-C, VLDL-C and FFA were significantly increased by CCl4. Both TAU and SIL (i.e., antioxidants) post-treatments were effectively able to relieve most of the above mentioned imbalances. However, the combination therapy was more effective than single applications in reducing TBARS levels, NO production, hydroxyproline content in fibrotic liver and the activity of serum GGT. Combined treatment (but not TAU- or SIL-alone) was also able to effectively prevent CCl4-induced decrease in adiponectin serum levels. Of note, the combined post-treatment with TAU+SIL (but not monotherapy) normalized serum FFA in CCl4-treated rats. The biochemical results were confirmed by histological and ultrastructural changes as compared to CCl4-poisoned rats. Therefore, on the basis of our work, TAU may be used in combination with SIL as an additional adjunct therapy to cure liver diseases such as fibrosis, cirrhosis and viral hepatitis.


Assuntos
Anti-Inflamatórios/uso terapêutico , Sequestradores de Radicais Livres/uso terapêutico , Cirrose Hepática/tratamento farmacológico , Fígado/patologia , Substâncias Protetoras/uso terapêutico , Silimarina/uso terapêutico , Taurina/uso terapêutico , Animais , Anti-Inflamatórios/farmacologia , Antioxidantes/metabolismo , Biomarcadores/metabolismo , Tetracloreto de Carbono , Citocinas/sangue , Sequestradores de Radicais Livres/farmacologia , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Hepatócitos/ultraestrutura , Lipídeos/sangue , Fígado/efeitos dos fármacos , Fígado/ultraestrutura , Cirrose Hepática/sangue , Masculino , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase/metabolismo , Substâncias Protetoras/farmacologia , Ratos Wistar , Silimarina/farmacologia , Taurina/farmacologia
6.
Lipids Health Dis ; 14: 128, 2015 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-26463841

RESUMO

BACKGROUND: This study investigated the possible roles of arginine (Arg) in ameliorating oxidative damage of intralipid (IL)-induced steatohepatitis (NASH). METHODS: NASH was induced in Sprague-Dawley rats by intravenous administration of 20 % IL for three weeks and then rats were pre- and post-treated with intraperitoneal injection of Arg for two weeks. Several biochemical parameters (blood and hepatic lipid peroxidation, glutathione, glutathione peroxidase and superoxide dismutase, hepatic cytochrome P450 2El monooxygenase (CYP2E1), nitric oxide (NO), endothelial nitric oxide synthase (eNOS) and tumor necrosis factor-α "TNF-α") and liver histopathology were detected for rat groups. RESULTS: The administration of Arg either before or after IL significantly ameliorated uncontrolled elevation of TBARS content, CYP2E1 activity (0.32 ± 0.01 or 0.3 ± 0.02 IU/mg) and TNF-α level. These effects were associated with a significant increase in the levels of glutathione, activities of antioxidant enzymes, NO level (1.649 ± 0.047 or 1.957 ± 0.073 µmol/g) and activity of hepatic eNOS (0.05 ± 0.002 or 0.056 ± 0.002 IU/mg) compared to the IL-treated rats. Moreover, the injection of Arg in NASH-induced rats showed normal hepatocytes, no steatosis and no bile duct proliferation but mild inflammation in the group which received IL after Arg. CONCLUSIONS: These results proved that pre- and post-treatment with Arg blocked oxidative stress-induced NASH by inhibiting CYP2E1 activity, decreasing TNF- α level and restoration activities of eNOS and antioxidant enzymes as well as glutathione level. This antioxidant effect of Arg leads to reverse signs of liver pathology of NASH with amelioration of liver and kidney functions.


Assuntos
Antioxidantes/farmacologia , Arginina/farmacologia , Fígado/efeitos dos fármacos , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Substâncias Protetoras/farmacologia , Animais , Citocromo P-450 CYP2E1/metabolismo , Emulsões , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Injeções Intraperitoneais , Injeções Intravenosas , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Masculino , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Hepatopatia Gordurosa não Alcoólica/induzido quimicamente , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/patologia , Fosfolipídeos , Ratos , Ratos Sprague-Dawley , Óleo de Soja , Superóxido Dismutase/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
7.
Oxid Med Cell Longev ; 2014: 476430, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25332751

RESUMO

BACKGROUND: The aim of this study is to investigate the protective effects of hemin (the heme oxygenase-1 [OH-1] inducer) against nephrotoxic effects induced by cisplatin [cis-diamminedichloroplatinum II (CP)] in male rats. METHODS: The evaluation was performed through monitoring renal redox parameters: lipid peroxidation (LPO), glutathione peroxidase (GPx), superoxide dismutase (SOD), glutathione reductase (GR), and reduced glutathione (GSH). The work also examined renal function tests (urea and creatinine), tissue proinflammatory mediator like nitric oxide (NO), and kidney cytopathology. RESULTS: A single intraperitoneal dose of CP (10 mg/kg b.w.) caused significant elevation of blood urea, serum creatinine, and renal LPO and NO, along with significant decline of the activities of GPx and GR, but renal SOD activity and GSH level were statistically insignificant as compared to control group. Subcutaneous injection of hemin (40 µmol/kg b.w.) partially ameliorated CP-induced renal damage, based on suppression of blood urea, serum creatinine, the renal MDA and NO levels, and increased antioxidant capacity in CP-treated rats. The results of histopathological and ultrastructural investigations supported the renoprotective effect of hemin against CP-induced acute toxicity. CONCLUSION: The induction of HO-1 by hemin is a promising approach in the treatment of CP-induced nephrotoxicity. However, further preclinical studies are warranted to test effectiveness of CP/hemin on the outcome of tumor chemotherapy.


Assuntos
Injúria Renal Aguda/induzido quimicamente , Cisplatino/toxicidade , Hemina/farmacologia , Injúria Renal Aguda/sangue , Injúria Renal Aguda/patologia , Animais , Interações Medicamentosas , Indução Enzimática/efeitos dos fármacos , Heme Oxigenase-1/biossíntese , Masculino , Oxirredução , Distribuição Aleatória , Ratos
8.
J Med Food ; 17(3): 339-49, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24650251

RESUMO

The effect of pomegranate juice (PJ) on hepatic antioxidant enzyme activities, lipid peroxidation, DNA fragmentation (DNAF), and caspase-3 activity in rats both treated and not treated with diethylnitrosamine (DEN) and phenobarbital (PB) was studied. Administration of rats with DEN and PB caused an elevation in the levels of malondialde-hyde (MDA), DNAF, and activities of glutathione reductase (GSR) and caspase-3, while the activities of superoxide dismutase, glutathione S-transferase, total glutathione peroxidase (t-GPx), and glutathione (GSH) level were decreased in hepatocytes compared to the control. Treatment of rats with PJ pre, during, and post DEN and PB administration improved liver function and decreased the levels of MDA, DNAF, t-GPx, GSR, and caspase-3 activities, but the GSH level did not change compared to the D-P group. This indicates that PJ reduced the oxidative stress and apoptosis induced by DEN and PB. Administration of healthy rats with PJ only for a long period induced oxidative stress and apoptosis for hepatocytes.


Assuntos
Bebidas/análise , Doença Hepática Induzida por Substâncias e Drogas/dietoterapia , Dietilnitrosamina/toxicidade , Lythraceae/metabolismo , Fenobarbital/toxicidade , Extratos Vegetais/metabolismo , Animais , Caspase 3/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Glutationa Transferase/metabolismo , Humanos , Fígado/efeitos dos fármacos , Fígado/enzimologia , Lythraceae/química , Masculino , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/química , Ratos , Ratos Sprague-Dawley , Superóxido Dismutase/metabolismo
9.
J Foot Ankle Surg ; 53(1): 12-5, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-23860130

RESUMO

Lengthening the tibia more than 25% of its original length can be indicated for proximal femoral deficiency, poliomyelitis, or femoral infected nonunion. Such lengthening of the tibia can adversely affect the ankle or foot shape and function. The present study aimed to assess the effect of tibial lengthening of more than 25% of its original length on the foot and ankle shape and function compared with the preoperative condition. This was a retrospective study of 13 children with severe proximal focal femoral deficiency, Aitken classification type D, who had undergone limb lengthening from June 2000 to June 2008 using Ilizarov external fixators. The techniques used in tibial lengthening included lengthening without intramedullary rodding and lengthening over a nail. The foot assessment was done preoperatively, at fixator removal, and then annually for 3 years, documenting the range of motion and deformity of the ankle and subtalar joints and big toe and the navicular height, calcaneal pitch angle, and talo-first metatarsal angle. At fixator removal, all cases showed equinocavovarus deformity, with decreased ankle, subtalar, and big toe motion. The mean American Orthopedic Foot and Ankle Society score was significantly reduced. During follow-up, the range of motion, foot deformity, and American Orthopedic Foot and Ankle Society score improved, reaching nearly to the preoperative condition by 2 years of follow-up. The results of our study have shown that tibial overlengthening has an adverse effect on foot and ankle function. This effect was reversible in the patients included in the present study. Lengthening of more than 25% can be safely done after careful discussion with the patients and their families about the probable effects of lengthening on foot and ankle function.


Assuntos
Fêmur/anormalidades , Desigualdade de Membros Inferiores/cirurgia , Tíbia/cirurgia , Adolescente , Articulação do Tornozelo/fisiopatologia , Criança , Feminino , Pé/fisiopatologia , Humanos , Técnica de Ilizarov , Masculino , Estudos Retrospectivos
10.
Food Chem ; 141(3): 1587-96, 2013 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-23870864

RESUMO

The present study is an attempt to reveal the protective role of Punica granatum peel and seed oil extracts against diethylnitrosamine (DEN) and phenobarbital (PB) induced hepatic injury in rats. DEN administration increased the levels of malondialdehyde (MDA), DNA fragmentation, caspase-3 and glutathione reductase (GSR) activities, while the level of reduced glutathione (GSH) and the activities of superoxide dismutase (SOD), glutathione S-transferase (GST) and total glutathione peroxidase (t-GPx) were decreased compared with the control. Treatment with peel and seed oil extracts pre, during and post DEN administration improved liver functions, decreased the levels of MDA, DNA fragmentation, caspase-3 and GSR activities with an elevation in levels of GSH, SOD, GST and t-GPx activities. This indicates that these extracts reduced the oxidative stress and apoptosis induced by DEN. Also the effect of administration of PE and SOE separately for a long time (23 weeks) on healthy rats was studied.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Lythraceae/química , Óleos de Plantas/administração & dosagem , Substâncias Protetoras/administração & dosagem , Sementes/química , Animais , Caspase 3/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Doença Hepática Induzida por Substâncias e Drogas/genética , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Fragmentação do DNA/efeitos dos fármacos , Dietilnitrosamina/efeitos adversos , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Humanos , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/enzimologia , Fígado/lesões , Masculino , Estresse Oxidativo/efeitos dos fármacos , Fenobarbital/efeitos adversos , Ratos , Ratos Sprague-Dawley , Superóxido Dismutase/metabolismo
11.
J. physiol. biochem ; 66(4): 291-299, dic. 2010.
Artigo em Inglês | IBECS | ID: ibc-122816

RESUMO

No disponible


Enzymes in mitochondria play an important role in biological oxidation and energy production. To understand the effect of schistosomiasis on these important processes, succinate cytochrome creductase (SCR) from control and Schistosoma-infected mice was subjected for investigation. In this article, we report that SCR from Schistosoma-infected mouse showed a significant decrease in its Vmax and K m compared to control using both cytochrome c and 2,6-dichlorophenolindophenol as substrates. Furthermore, the kinetic studies of the purified SCR in the absence and presence of the schistosomicidal drugs praziquantel and Commiphora extract reveal that both drugs have an inhibitory action on the enzyme from the control and Schistosoma-infected mice and praziquantel changes the type of inhibition of SCR towards cytochrome c from mixed type in control to a competitive one in the case of the infection (AU)


Assuntos
Animais , Camundongos , Succinato Citocromo c Oxirredutase/farmacocinética , Esquistossomose/tratamento farmacológico , Schistosoma , Esquistossomicidas/farmacocinética , Modelos Animais de Doenças
12.
J Physiol Biochem ; 66(4): 291-9, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20680542

RESUMO

Enzymes in mitochondria play an important role in biological oxidation and energy production. To understand the effect of schistosomiasis on these important processes, succinate cytochrome c reductase (SCR) from control and Schistosoma-infected mice was subjected for investigation. In this article, we report that SCR from Schistosoma-infected mouse showed a significant decrease in its Vmax and Km compared to control using both cytochrome c and 2,6-dichlorophenolindophenol as substrates. Furthermore, the kinetic studies of the purified SCR in the absence and presence of the schistosomicidal drugs praziquantel and Commiphora extract reveal that both drugs have an inhibitory action on the enzyme from the control and Schistosoma-infected mice and praziquantel changes the type of inhibition of SCR towards cytochrome c from mixed type in control to a competitive one in the case of the infection.


Assuntos
Esquistossomose/enzimologia , Esquistossomicidas/uso terapêutico , Succinato Citocromo c Oxirredutase/antagonistas & inibidores , Succinato Citocromo c Oxirredutase/química , 2,6-Dicloroindofenol/química , Animais , Temperatura Alta , Técnicas In Vitro , Cinética , Masculino , Camundongos , Mitocôndrias/enzimologia , Praziquantel/farmacologia , Reprodutibilidade dos Testes , Temperatura
13.
J Biochem Mol Biol ; 37(2): 223-8, 2004 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-15469699

RESUMO

The levels of arylsulfatases A and B, alpha-amylase, aspartate transcarbamylase, and gamma-glutamyl transpeptidase were investigated during the infection of mice with schistosoma mansoni. This infection caused a significant (p < 0.001) increase in the activity of hepatic arylsulfatase B (ASB), aspartate transcarbamylases and gamma-glutamyl transpeptidase. A non-significant difference occurred for alpha-amylase (p < 0.3) and arylsulfatase A (p > 0.5) when compared to the control. The specific activity of hepatic ASB was progressively increased with the progression of the Schistosoma-infection. Moreover, the kinetic studies of hepatic ASB in Schistosoma-infection showed that a slight decrease in the value of K(m) and about a 40% increase in V(max) when compared to the control. In addition, the pH optimum of hepatic ASB was altered from 6 to 7 as a result of schistosomiasis. These observations suggest that there are schistosomiasis-associated changes of the catalytic and kinetic properties of hepatic ASB.


Assuntos
Aspartato Carbamoiltransferase/metabolismo , Cerebrosídeo Sulfatase/metabolismo , N-Acetilgalactosamina-4-Sulfatase/metabolismo , Esquistossomose/enzimologia , alfa-Amilases/metabolismo , gama-Glutamiltransferase/metabolismo , Animais , Catálise , Estabilidade Enzimática , Concentração de Íons de Hidrogênio , Cinética , Fígado/enzimologia , Hepatopatias Parasitárias/enzimologia , Masculino , Camundongos , Schistosoma mansoni/parasitologia , Temperatura
14.
Comp Biochem Physiol C Toxicol Pharmacol ; 135(4): 405-14, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12965185

RESUMO

The effect of Dipel (D), a Bacillus thuringiensis-based bioinsecticide, on hepatic antioxidant enzyme activities and lipid peroxidation in rat liver was investigated. Administration of D in a dose of 1 mg/100 g body mass for 4 successive days increased the activities of glutathione peroxidase (GPx), glutathione reductase (GR) and the level of malondialdehyde (MDA) in rat hepatocytes. The activity of superoxide dismutase (SOD) and glutathione (GSH) level were decreased. Administration of D in rats pretreated with alpha-tocopherol (alphaT) or acetylsalicylic acid (ASA) decreased the activities of GPx, GR and MDA levels, while the GSH level was increased compared with rats treated with D alone. The SOD activity was increased in rats pretreated with alphaT before D, but decreased on pretreatment with ASA, compared with rats treated with D alone. The results indicated that D induced oxidative stress in rat liver that has been protected by prior administration of alphaT or ASA.


Assuntos
Antioxidantes/farmacologia , Aspirina/farmacologia , Proteínas de Bactérias/toxicidade , Toxinas Bacterianas , Endotoxinas/toxicidade , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , alfa-Tocoferol/farmacologia , Animais , Aspirina/análogos & derivados , Bacillus thuringiensis/química , Toxinas de Bacillus thuringiensis , Sequestradores de Radicais Livres/farmacologia , Glutationa/análise , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Glutationa Redutase/metabolismo , Proteínas Hemolisinas , Fígado/metabolismo , Masculino , Malondialdeído/análise , Malondialdeído/metabolismo , Ratos , Ratos Wistar , Selênio/metabolismo , Superóxido Dismutase/metabolismo
15.
J Hypertens ; 20(6): 1157-63, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12023686

RESUMO

OBJECTIVE: Angiotensin II-receptor blockers are an established class of antihypertensive agents, but the differences between individual members of the class are largely unknown. The present study employed an animal model to demonstrate angiotensin II-receptor blocker-specific effects and to quantify these differences by comparing two common agents, losartan and valsartan. METHODS: We measured the effects on angiotensin II AT2-receptor-mediated renal cGMP by microdialysis in the outer renal cortex in conscious normotensive, sodium-depleted, 4-week-old Sprague-Dawley rats. Rats (n = 8) were given equimolar and equidepressor doses of losartan (0.02 mmol/kg) or valsartan (0.02 mmol/kg) either intravenously or orally. Time was allowed for the conversion of losartan into its active metabolite, EXP 3174. RESULTS: Both drugs had equal effects on blood pressure. There were significantly greater increases in cGMP levels after administration of valsartan than of losartan with both routes of administration. Intravenous administration of valsartan led to a 69.1% increase in cGMP, versus a 10.3% increase with losartan. Five hours after oral administration of valsartan, a 48% increase in cGMP was observed versus a 10.9% increase with losartan. The increase after oral administration of valsartan was sustained 8 h after administration, whereas the effect of losartan was not sustained. The effects of losartan and valsartan on cGMP were completely inhibited by AT2-receptor blockade. CONCLUSION: The results indicate that AT1-receptor blockade with valsartan influences AT2-receptor-mediated angiotensin II responses to a greater extent than with losartan, as quantified by renal interstitial fluid cGMP.


Assuntos
Antagonistas de Receptores de Angiotensina , GMP Cíclico/metabolismo , Espaço Extracelular/metabolismo , Rim/metabolismo , Losartan/farmacologia , Receptores de Angiotensina/efeitos dos fármacos , Tetrazóis/farmacologia , Valina/análogos & derivados , Valina/farmacologia , Administração Oral , Angiotensina II/metabolismo , Animais , Pressão Sanguínea/efeitos dos fármacos , Feminino , Imidazóis/administração & dosagem , Imidazóis/farmacologia , Injeções Intravenosas , Losartan/administração & dosagem , Piridinas/administração & dosagem , Piridinas/farmacologia , Ratos , Ratos Sprague-Dawley , Receptor Tipo 1 de Angiotensina , Receptor Tipo 2 de Angiotensina , Tetrazóis/administração & dosagem , Valina/administração & dosagem , Valsartana
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