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1.
Life Sci ; 344: 122559, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38479595

RESUMO

AIMS: Cinnamaldehyde (CA), the main active constituent of cinnamon oil, is reported to have neuroprotective effects. However, the potential benefits of CA for brain protection in hepatic encephalopathy (HE) are still not understood. Thus, the present study investigates the possible ameliorative effect of CA (70 mg/kg/day, I.P.) either alone or in combination with lactulose (Lac) (5.3 g/kg/day, oral) against thioacetamide (TAA)-induced hepatic encephalopathy in rats. MATERIALS AND METHODS: For induction of HE, TAA (200 mg/kg) was intraperitoneally administered for 1 week at alternative days. CA, Lac and Lac+CA were administered for 14 days prior to and for further 7 days together with TAA injection. KEY FINDINGS: CA, Lac and Lac+CA combination effectively attenuated TAA-induced HE; as indicated by the improvement in behavioral tests, mitigation of pathological abnormalities in both liver and brain, the significant reduction in serum hyperammonemia and amelioration in liver function biomarkers; ALT and AST. This was accompanied with a substantial restoration of redox state in liver and brain; MDA and GSH levels. Moreover, CA, Lac and Lac+CA combination reduced neuroinflammation as demonstrated by the notable attenuation of P2X7R, NLRP3, caspase-1, IL-1ß, GFAP and Iba1 brain levels, as well as the amelioration of brain edema as manifested by reduction in AQP4 levels in brain. SIGNIFICANCE: Our study has demonstrated that CA in combination with Lac possesses a superior neuroprotective effect over Lac alone against TAA-induced HE by attenuation of P2X7R/NLRP3 mediated neuroinflammation and relieving brain edema.


Assuntos
Acroleína/análogos & derivados , Edema Encefálico , Encefalopatia Hepática , Ratos , Animais , Encefalopatia Hepática/induzido quimicamente , Encefalopatia Hepática/tratamento farmacológico , Lactulose/efeitos adversos , Inflamassomos , Tioacetamida/farmacologia , Edema Encefálico/patologia , Proteína 3 que Contém Domínio de Pirina da Família NLR , Doenças Neuroinflamatórias , Ratos Wistar , Fígado
2.
Phytother Res ; 38(3): 1367-1380, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38217097

RESUMO

Liver fibrosis affects approximately 800 million patients worldwide, with over 2 million deaths each year. Nevertheless, there are no approved medications for treating liver fibrosis. In this study, we investigated the impacts of ginkgetin on liver fibrosis and the underlying mechanisms. The impacts of ginkgetin on liver fibrosis were assessed in mouse models induced by thioacetamide or bile duct ligation. Experiments on human LX-2 cells and primary mouse hepatic stellate cells (HSCs) were performed to explore the underlying mechanisms, which were also validated in the mouse models. Ginkgetin significantly decreased hepatic extracellular matrix deposition and HSC activation in the fibrotic models induced by thioacetamide (TAA) and bile duct ligation (BDL). Beneficial effects also existed in inhibiting hepatic inflammation and improving liver function. In vitro experiments showed that ginkgetin markedly inhibited HSC viability and induced HSC apoptosis dose-dependently. Mechanistic studies revealed that the antifibrotic effects of ginkgetin depend on STAT1 activation, as the effects were abolished in vitro after STAT1 silencing and in vivo after inhibiting STAT1 activation by fludarabine. Moreover, we observed a meaningful cross-talk between HSCs and hepatocytes, in which IL-6, released by ginkgetin-induced apoptotic HSCs, enhanced hepatocyte proliferation by activating STAT3 signaling. Ginkgetin exhibits antifibrotic effects by inducing HSC apoptosis via STAT1 activation and enhances hepatocyte proliferation secondary to HSC apoptosis via the IL-6/STAT3 pathway.


Assuntos
Biflavonoides , Células Estreladas do Fígado , Tioacetamida , Camundongos , Animais , Humanos , Tioacetamida/metabolismo , Tioacetamida/farmacologia , Tioacetamida/uso terapêutico , Interleucina-6/metabolismo , Cirrose Hepática/tratamento farmacológico , Modelos Animais de Doenças , Apoptose , Fígado/metabolismo , Fator de Transcrição STAT1/metabolismo , Fator de Transcrição STAT1/farmacologia
3.
Horm Mol Biol Clin Investig ; 44(4): 371-377, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-38124628

RESUMO

OBJECTIVES: Liver cirrhosis is one of the most important causes of death from liver diseases. Nowadays, the use of herbal medicines has increased due to its availability, less side effects and cheapness for the treatment of liver diseases. The present study was conducted to examine therapeutic effects of hydroalcoholic extract of Scrophularia striata (S. striata) on thioacetamide-induced liver cirrhosis in rats through evaluate its effects on oxidative stress markers and the expression of metalloproteinase 1 (TIMP 1), toll-like receptor-4 (TLR-4), and Mitofusin (MFN2) genes. METHODS: 24 male rats were selected by simple random sampling. Rats were randomly assigned to four groups: group I: healthy rats, group II: thioacetamide (TAA) injected rats, group III: TAA injected rats+100 mg/kg bw of S. striata and group IV: TAA injected rats+200 mg/kg bw of S. striata. Liver cirrhosis was induced in rats by a 300 mg/kg bw TAA administration twice with an interval of 24 h. After 8 weeks of treatment by S. striata at doses of 100 and 200 mg/kg bw, biochemical factors and oxidative stress markers (SOD, TAC, GPX, CAT and MDA) were measured using spectrophotometric methods. Also, gene expression of TIMP 1, TLR-4, and MFN2 were analyzed using real-time PCR. ANOVA and Bonferroni post hoc test analysis were applied to evaluate the data. RESULTS: The results showed the S. striata extract significantly improve the serum ALT, AST and ALP levels, TIMP 1, TLR-4, and MFN2 genes and oxidative stress markers (SOD, TAC, GPX, CAT and MDA) in the liver tissues when compared to control group (p<0.05). Also, it was found that the beneficial effects of the S. striata were dose-dependent. CONCLUSIONS: Based on the results obtained S. striata by reducing the expression of TIMP 1, TLR-4, and MFN2 genes and improving oxidative stress might be used as adjuvant treatment for liver cirrhosis.


Assuntos
Hepatopatias , Scrophularia , Ratos , Masculino , Animais , Tioacetamida/metabolismo , Tioacetamida/farmacologia , Scrophularia/metabolismo , Receptor 4 Toll-Like/genética , Inibidor Tecidual de Metaloproteinase-1/metabolismo , Inibidor Tecidual de Metaloproteinase-1/farmacologia , Ratos Wistar , Cirrose Hepática/tratamento farmacológico , Cirrose Hepática/metabolismo , Cirrose Hepática/patologia , Estresse Oxidativo , Fígado/metabolismo , Hepatopatias/metabolismo , Hepatopatias/patologia , Superóxido Dismutase/metabolismo
4.
Zhongguo Zhong Yao Za Zhi ; 47(21): 5882-5889, 2022 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-36472007

RESUMO

This study aims to investigate the therapeutic effect of icariin(ICA) on thioacetamide(TAA)-induced femoral osteolysis in rats. RAW264.7 cells were treated with TAA and ICA. Cell counting kit-8(CCK-8) assay was used to detect cell proliferation, and tartrate-resistant acid phosphatase(TRAP) staining to examine the formation of osteoclasts. The expression of TRAP, cathepsin K, c-FOS, and NFATc1 in RAW264.7 cells was determined by Western blot and immunofluorescence method. Thirty-two SD rats were randomized into the control group, TAA group(intraperitoneal injection of TAA at 300 mg·kg~(-1)), ICA group(gavage of ICA at 600 mg·kg~(-1)) and TAA + ICA group(intraperitoneal injection of TAA at 300 mg·kg~(-1) and gavage of ICA at 600 mg·kg~(-1)). Administration was performed every other day for 6 weeks. Body weight and length of femur were recorded at execution. Pathological injury and osteoclast differentiation of femur were observed based on hematoxylin-eosin(HE) staining and TRAP staining, and the changes of bone metabolism-related indexes alkaline phosphatase(ALP), calcium(Ca), phosphorus(P), magnesium(Mg), and cross-linked N-telopeptide of type Ⅰ collagen(NTX-Ⅰ) in serum were detected. Three-point bending test and micro-CT were applied to evaluate the quality of femur, and Western blot to detect the levels of osteoclast-related proteins TRAP, cathepsin K, RANK, RANKL, p38, p-p38, ERK, p-ERK, JNK, p-JNK, c-Fos, and NFATc1. The results showed ICA could inhibit TAA-induced production of TRAP-positive cells, the expression of osteoclast-related proteins, and nuclear translocation of NFATc1. ICA alleviated the weight loss, reduction of femur length, and growth inhibition induced by TAA in SD rats. ICA ameliorated the decline of femur elastic modulus caused by TAA and significantly restored trabecular bone mineral density(BMD), trabecular pattern factor(Tb.Pf), trabecular number(Tb.N), trabecular thickness(Tb.Th), and structure model index(SMI), thus improving bone structure. Western blot results showed ICA suppressed femoral osteoclast differentiation induced by TAA through RANKL-p38/ERK-NFATc1 signaling pathway. ICA inhibits osteoclast differentiation and prevents TAA-induced osteolysis by down-regulating RANKL-p38/ERK-NFAT signaling pathway.


Assuntos
Reabsorção Óssea , Osteólise , Ratos , Animais , Osteoclastos , Catepsina K/genética , Catepsina K/metabolismo , Catepsina K/farmacologia , Tioacetamida/metabolismo , Tioacetamida/farmacologia , Reabsorção Óssea/metabolismo , Reabsorção Óssea/patologia , Osteólise/metabolismo , Osteólise/patologia , Diferenciação Celular , Ratos Sprague-Dawley , Fatores de Transcrição NFATC/genética , Fatores de Transcrição NFATC/metabolismo
5.
Pak J Pharm Sci ; 33(4): 1519-1525, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33583782

RESUMO

The present research work was designed to evaluate the effects of curcumin supplementation on various biochemical parameters in rats with thioacetamide (TAA) induced liver cirrhosis. For this purpose 24 male Albino Wistar rats were randomly distributed into four groups (n=6).Group I served as control, Group II and Group III received thioacetamide 200mg/kg b.w, i.p, twice a week for 12 weeks in first phase. In second phase Group II received saline and Group III received curcumin 50mg/kg b.w/day, i.p for 12 weeks, in second phase, Group IV received curcumin 50mg/kg b.w/day, i.p, for 12 weeks, in first phase and saline in second phase. Evaluation of histopathological and biochemical parameters was carried out by liver histopathology and estimation of total and direct bilirubin, liver specific enzymes, antioxidant enzymes, MDA level, plasma and intraerythrocyte sodium and potassium respectively. Histopathology of liver showed highest degree of fibrosis and nodule formation, significant alteration in biochemical parameters indicated development of severe liver cirrhosis. Curcumin treatment showed reduced amount of fibrosis and significant reduction in level of liver biomarkers, reversal of antioxidant enzymes (SOD and GSH), MDA level, catalase activity and regain of electrolyte homeostasis. These findings confirm the protective role of curcumin in liver cirrhosis.


Assuntos
Curcumina/farmacologia , Cirrose Hepática/tratamento farmacológico , Fígado/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Animais , Antioxidantes/metabolismo , Biomarcadores/metabolismo , Homeostase/efeitos dos fármacos , Fígado/metabolismo , Cirrose Hepática/metabolismo , Masculino , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Wistar , Tioacetamida/farmacologia
6.
Biosci Biotechnol Biochem ; 84(1): 171-177, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31476130

RESUMO

We tested the hypothesis that α-lactalbumin inhibits the disruption of intestinal barrier function and liver cirrhosis by restoring gut-liver axis function in thioacetamide (TAA) -treated rats. Rat diets were supplemented with α-lactalbumin replacing 50% of dietary protein. After consuming α-lactalbumin for one week, rats were intraperitoneally injected with TAA twice a week for 14 weeks. The α-lactalbumin-enriched diet significantly inhibited the elevation of plasma alanine aminotransferase, aspartate aminotransferase, and hyaluronic acids. The supplement significantly reduced plasma lipopolysaccharide levels and increased occludin mRNA level. Hepatic fibrosis and regenerative nodules was developed and intestinal villi were shortened by TAA; α-Lactalbumin attenuated these histopathological changes. These results indicated that α-lactalbumin improved intestinal barrier function, suppressing endotoxin levels. These data also suggested that α-lactalbumin ameliorated the impairment of the gut-liver axis by TAA, inhibiting the development of liver cirrhosis.


Assuntos
Suplementos Nutricionais , Trato Gastrointestinal/efeitos dos fármacos , Lactalbumina/uso terapêutico , Cirrose Hepática Experimental/induzido quimicamente , Cirrose Hepática Experimental/dietoterapia , Fígado/efeitos dos fármacos , Substâncias Protetoras/uso terapêutico , Tioacetamida/farmacologia , Alanina Transaminase/sangue , Animais , Aspartato Aminotransferases/sangue , Fibrose/tratamento farmacológico , Trato Gastrointestinal/metabolismo , Expressão Gênica/efeitos dos fármacos , Ácido Hialurônico/sangue , Injeções Intraperitoneais , Lipopolissacarídeos/sangue , Fígado/metabolismo , Fígado/patologia , Cirrose Hepática Experimental/prevenção & controle , Masculino , RNA Mensageiro/genética , Ratos , Ratos Sprague-Dawley , Tioacetamida/administração & dosagem , Proteínas de Junções Íntimas/genética
7.
Biomed Pharmacother ; 89: 332-341, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28237915

RESUMO

For thousands of years, the plant-based natural products have been a source of curative agents for various ailments. Butea monosperma (Fabaceae) has an important place in Indian traditional system of medicine for curing number of disorders. The present study deals with evaluation of hepatoprotective properties of ethyl acetate fraction (Beac) from B. monosperma bark in rat model. In preliminary antioxidant studies, Beac demonstrated pronounced superoxide scavenging (IC50 88.85µg/ml) and anti-lipid peroxidation (IC50 131.66µg/ml) potential. In animal studies, Beac showed protective effect against thioacetamide-induced pathophysiology in liver of male Wistar rats. The levels of different parameters related to hepatic functions were altered by thioacetamide treatment (300mg/g bw) in rats. The pre-treatment of rats with Beac (50, 100 and 200mg/kg bw) was able to normalize the biochemical markers viz. serum bilirubin, SGOT, SGPT, albumin and ALP along with liver antioxidative molecules viz. SOD, CAT, GSH and GR. Results of histopathological and colorimetric studies revealed that Beac treatment also restored the markers of fibrosis i.e. collagen and hydroxyproline towards normal level. Beac considerably inhibited thioacetamide-induced expression of p-PI3K, p-Akt and p-mTOR in hepatocytes as revealed from immunohistochemical studies. This finding is the first evidence of inhibitory action of B. monosperma bark on these pro-carcinogenic proteins. HRMS analysis revealed the presence of quercetin, buteaspermin B and ononin in Beac fraction of Butea monosperma. From the results, it can be concluded that B. monosperma bark is a rich source of phytochemicals with in vitro and in vivo protective activities which deserves further mechanistic studies for its use as a hepatoprotective agent in the prevention of hepatic inflammation and its related malignancies.


Assuntos
Butea/química , Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Fígado/efeitos dos fármacos , Extratos Vegetais/farmacologia , Substâncias Protetoras/farmacologia , Tioacetamida/farmacologia , Animais , Antioxidantes/farmacologia , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/metabolismo , Masculino , Fosfatidilinositol 3-Quinases/metabolismo , Ratos , Ratos Wistar
8.
Eur J Pharmacol ; 728: 9-15, 2014 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-24534491

RESUMO

Hepatic stellate cell activation is a key cellular event in the development of liver fibrosis. Recently, Delta-like homolog 1 (DLK1) protein level has been shown to increase in HSC activation and serve as a new contributor to HSC activation and liver fibrosis. Curcumin, a natural yellow polyphenol, possesses therapeutic roles in many diseases including liver fibrosis and has long been used in traditional medicine. The present study was aimed to elucidate the effect of curcumin on DLK1 expression in HSCs in vitro and in vivo, which is still unknown. Our results demonstrated that curcumin reduced DLK1 expression in culture-activated HSCs and in rat model of liver fibrosis. The inhibitory effect of curcumin on DLK1 expression may be mediated in part by interruption of Shh signaling pathway, which contributes to the promotion effect of curcumin on the expression of PPAR-gamma, a key factor in inhibiting HSC activation. Our results in this study may reveal a new mechanisms through which curcumin exerts its inhibitory effect on HSC activation and liver fibrosis.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Curcumina/farmacologia , Expressão Gênica/efeitos dos fármacos , Células Estreladas do Fígado/efeitos dos fármacos , Peptídeos e Proteínas de Sinalização Intercelular/genética , Cirrose Hepática/prevenção & controle , Proteínas de Membrana/genética , Animais , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/uso terapêutico , Western Blotting , Células Cultivadas , Curcumina/administração & dosagem , Curcumina/uso terapêutico , Modelos Animais de Doenças , Células Estreladas do Fígado/metabolismo , Células Estreladas do Fígado/patologia , Cirrose Hepática/genética , Cirrose Hepática/patologia , Ratos , Ratos Sprague-Dawley , Tioacetamida/farmacologia
9.
Hum Exp Toxicol ; 30(9): 1322-32, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21071552

RESUMO

Chunggan extract (CGX) is a hepatotherapeutic herbal formula which has been traditionally used for patients suffering from various hepatic disorders. This study aimed to elucidate antifibrotic effect and mechanisms of CGX in thioacetamide (TAA) model. Hepatic fibrosis was induced in 45 Sprague-Dawley rats by TAA (200 mg kg(-1), intraperitoneally [ip]) on twice per week for 12 weeks. CGX (100 or 200 mg kg(-1), per oral [po]) was administrated once a day throughout the experiment. CGX treatment ameliorated serum biomarkers. CGX administration significantly attenuated distortion of histopathologic finding, and accumulation of hydroxyproline and malondialdehyde (MDA). CGX treatment significantly decreased transforming growth factor-beta (TGF-ß) concentrations and inactivated hepatic stellate cells (HSCs). CGX treatment drastically restored glutathione (GSH) system, while inducible nitric oxide synthase (iNOS) and tumor necrosis factor-alpha (TNF-α) significantly down-regulated in liver tissue. CGX showed antifibrotic effect in thioacetamide-induced chronic liver injury model. Its corresponding mechanisms may be mediated via anti-oxidative stress property sustaining GSH system and inhibition of ROS production.


Assuntos
Medicamentos de Ervas Chinesas/uso terapêutico , Glutationa/metabolismo , Cirrose Hepática Experimental/prevenção & controle , Fígado/efeitos dos fármacos , Tioacetamida/farmacologia , Animais , Biomarcadores/sangue , Medicamentos de Ervas Chinesas/administração & dosagem , Fígado/enzimologia , Fígado/metabolismo , Fígado/patologia , Cirrose Hepática Experimental/induzido quimicamente , Cirrose Hepática Experimental/metabolismo , Testes de Função Hepática , Masculino , Medicina Tradicional Coreana , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley
10.
Biosci Biotechnol Biochem ; 74(4): 781-7, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20378990

RESUMO

Anoectochilus formosanus is used in traditional folk medicine as an hepatoprotective agent. The purpose of this study was to investigate the effects of a standardized aqueous extract of A. formosanus (SAEAF) on thioacetamide (TAA)-induced liver fibrosis. An in vitro study showed that the inhibitive effect of kinsenoside, a major component of SAEAF, on tumor necrosis factor alpha (TNF-alpha) secretion from Kupffer cells might be derived at least partly from downregulation of LPS-receptor Toll-like receptor 4 (TLR4) signaling. Hepatic fibrosis was produced by TAA (200 mg/kg, i.p.) 3 times per week for 12 weeks. Mice in the three TAA groups were treated daily with distilled water and SAEAF (1.0, 0.2 g/kg) via gastrogavage throughout the experimental period. The mice that received the SAEAF treatment had significantly reduced plasma alanine aminotransferase activity, relative liver weights, and hepatic hydroxyproline contents. A histological examination also confirmed that SAEAF reduced the degree of fibrosis caused by TAA treatment. RT-PCR analysis showed that SAEAF treatment reduced mRNA expression of collagen (alpha1)(I), lipopolysaccharide-binding protein, CD14, TLR4, and TNF receptor 1. An immunohistochemical examination also indicated that SAEAF reduced the number of CD68-positive cells (macrophages). In conclusion, oral administration of SAEAF significantly reduced TAA-induced hepatic fibrosis in mice, probably through inhibition of hepatic Kupffer cell activation.


Assuntos
Células de Kupffer/metabolismo , Cirrose Hepática/patologia , Proteínas de Fase Aguda , Animais , Antígenos CD/metabolismo , Antígenos CD/farmacologia , Antígenos de Diferenciação Mielomonocítica/metabolismo , Proteínas de Transporte , Regulação para Baixo/efeitos dos fármacos , Hidroxiprolina/efeitos adversos , Hidroxiprolina/metabolismo , Lipopolissacarídeos/efeitos adversos , Lipopolissacarídeos/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Cirrose Hepática/induzido quimicamente , Cirrose Hepática/metabolismo , Masculino , Medicina Tradicional , Glicoproteínas de Membrana , Camundongos , Camundongos Endogâmicos BALB C , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/efeitos dos fármacos , Tioacetamida/efeitos adversos , Tioacetamida/metabolismo , Tioacetamida/farmacologia , Receptor 4 Toll-Like/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
11.
Indian J Exp Biol ; 45(7): 626-9, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17821859

RESUMO

Efficacy of a herbal product of E. officinalis (fruit) (EO) has been evaluated against carbon tetrachloride (CCl4) and thioacetamide (TAA) induced changes in rat liver. Chronic treatment of CCl4 and TAA revealed abnormal histopathology indicative of pre-fibrogenic events. EO reversed such alterations with significant regenerative changes suggestive of its preventive role in prefibrogenesis of liver.


Assuntos
Tetracloreto de Carbono/farmacologia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Phyllanthus emblica/metabolismo , Extratos Vegetais/metabolismo , Tioacetamida/farmacologia , Animais , Carcinógenos/análise , Avaliação Pré-Clínica de Medicamentos , Cirrose Hepática , Ratos , Ratos Wistar , Toxinas Biológicas
12.
Mol Cell Biochem ; 185(1-2): 1-6, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9746205

RESUMO

Effects of selenium deficiency, induced by thioacetamide, were investigated in rats. Thioacetamide (0.3 g/L) given in drinking water, as expected, caused a significant loss of selenium from the liver. It was accompanied by liver cirrhosis and a significant increase in the liver weight as well as liver to body weight ratio. A significant loss of selenium from spleen was also accompanied by an increase in its weight. Weights of lungs, testis and kidney, however, were not affected by thioacetamide and there was no change in their selenium content. Plasma levels of selenium were significantly reduced in the thioacetamide treated group. All these changes were confirmed to be due to selenium deficiency caused by thioacetamide, as supplementation with selenium reversed these changes. The mode of action of selenium is unknown but may involve anti-oxidant defense mechanisms.


Assuntos
Cirrose Hepática Experimental/induzido quimicamente , Selênio/deficiência , Tioacetamida/farmacologia , Animais , Fígado/química , Fígado/efeitos dos fármacos , Cirrose Hepática Experimental/patologia , Masculino , Ratos , Ratos Wistar , Selênio/metabolismo
13.
Biochem Pharmacol ; 37(3): 497-502, 1988 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-3337747

RESUMO

Hyperthermia produced a decrease of ornithine decarboxylase activity in different tissues of adult rats. The fall in ornithine decarboxylase was dependent on time of exposure and temperature. The decay of ornithine decarboxylase activity in liver, brain, kidney, heart, spleen and testes was rather similar. The t1/2 for liver ornithine decarboxylase determined by the hyperthermic treatment (40 degrees ambient temperature) was 20 min. Ornithine decarboxylase activity was recovered in all tissues exposed to the hyperthermic shock after a period of 4 hours, although the degree of recovery was dependent on the type of tissue. The effect that hyperthermia produces on ornithine decarboxylase activity in rats could be related to an inhibition in the synthesis of active enzyme rather than to a specific degradation or inactivation of ornithine decarboxylase molecule.


Assuntos
Hipertermia Induzida , Fígado/enzimologia , Ornitina Descarboxilase/metabolismo , Aminoácidos/metabolismo , Animais , Cicloeximida/farmacologia , Indução Enzimática , Estabilidade Enzimática , Temperatura Alta , Fígado/efeitos dos fármacos , Masculino , Especificidade de Órgãos , Ornitina Descarboxilase/biossíntese , Ratos , Ratos Endogâmicos , Tioacetamida/farmacologia
14.
Biochim Biophys Acta ; 719(3): 518-26, 1982 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-6217846

RESUMO

The changes in the activity of nicotinamide: S-adenosylmethionine methyltransferase (nicotinamide methylase) were studied in rat liver which was subjected to different rates of cellular proliferation. The cytosolic enzyme activity increased 3-4-fold in the first 24-48 h after partial hepatectomy and decreased again to the basal levels until 4 days post-operatively, whereas it remained unchanged in the livers of sham-operated animals. A single administration of thioacetamide at a dose of 50-250 mg/kg body weight, a treatment which induces hepatocellular proliferation as well, also enhanced the enzyme activity 2-3-fold 24 h after drug administration. This activity increase was associated with a marked lowering of intracellular NAD content of as much as 50% of the control levels. D-Galactosamine, a known hepatotoxic agent causing acute hepatitis in experimental animals and preventing DNA synthesis in regenerating liver, blocked the activity increase in regenerating rat liver. The rate of 1-methylnicotinamide synthesis, as measured by incubating liver slices in the culture medium supplemented with [14C]nicotinamide as a precursor, was found to be 2-4 times higher in the slices from regenerating liver and thioacetamide-treated rat liver than those from non-proliferating control liver. These results, together with our previous finding on the enhancement by 1-methylnicotinamide of the growth of cultured rat liver cells (Hoshino, J., Kühne, U. and Kröger, H. (1982) Biochem. Biophys. Res. Commun. 105, 1446-1452), support the view that nicotinamide methylase and its product, 1-methyl-nicotinamide, are involved in the control of hepatocellular DNA synthesis and proliferation.


Assuntos
Regeneração Hepática , Fígado/enzimologia , Metiltransferases/metabolismo , Niacinamida/metabolismo , Animais , Citosol/enzimologia , Cinética , Fígado/efeitos dos fármacos , Masculino , Metilação , Nicotinamida N-Metiltransferase , Ratos , Ratos Endogâmicos , Tioacetamida/farmacologia
15.
Rev Esp Fisiol ; 38 Suppl: 135-40, 1982.
Artigo em Espanhol | MEDLINE | ID: mdl-7146568

RESUMO

The effect of thioacetamide on rat liver phospholipids biosynthesis was investigated using 32P as precursor. The incorporation of 32P-ortophosphate in the polar lipid fraction and the specific radioactivities of individual phospholipids in the liver fraction and the specific radioactivities of individual phospholipids in the liver of control rats and rats treated with thioacetamide were determined 75 min after intraperitoneal administration of 32P-ortophosphate. Intraperitoneal injection of thioacetamide (daily dose of 100 mg/kg body weight) in male Wistar rats resulted in an increase of 32P incorporation in the over-all phospholipids, after 8 doses administration and a significant decrease during the chronic intoxication. Specific activity of phosphatidylcholine decreased and a parellel increase in specific radioactivity of lisophosphatidylcholine was found after three days of thioacetamide treatment. There was also observed a marked increase in specific radioactivity of sphingomyelin, which could be due to a stimulation of CDP-choline: ceramide cholinephosphotransferase reaction with subsequent diminution of the rate of phosphatidylcholine synthesis via the CDP-amine pathway (involving cytidine diphosphocholine).


Assuntos
Acetamidas/farmacologia , Fígado/efeitos dos fármacos , Fosfolipídeos/biossíntese , Fósforo/metabolismo , Tioacetamida/farmacologia , Animais , Fígado/metabolismo , Lisofosfatidilcolinas/biossíntese , Masculino , Fosfatidilcolinas/biossíntese , Fosfatidiletanolaminas/biossíntese , Ratos , Esfingomielinas/biossíntese
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