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1.
J Clin Monit Comput ; 34(5): 1087-1093, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31628569

RESUMO

We evaluated the performance of the Surgical Plethysmographic Index (SPI) and the Analgesia Nociception Index (ANI) as surrogate pain measures and determined their respective cut-off values for detecting pain in conscious postoperative patients. In total, 192 patients after elective surgery were enrolled. Baseline SPI and ANI data were acquired for 10 min in the operating room prior to surgery when the patients rated their pain as 0 on the numerical rating scale (NRS). Upon arrival in the post-anaesthesia care unit (PACU) after surgery, SPI and ANI data were recorded for 10 min. The means of the recorded data at OR and PACU were defined as the values representing baseline and postoperative pain, respectively. SPI and ANI data obtained from 189 patients were analysed, who were anesthetized with propofol (n = 149) or sevoflurane (n = 40). Remifentanil was continuously infused intraoperatively in all patients. The values of SPI and ANI were significantly different in conscious patients without (NRS = 0) and with pain (NRS > 0). The areas under the receiver operating curves for SPI and ANI were 0.73 (P < 0.0001) and 0.67 (P < 0.0001), respectively. The cut-off values for SPI and ANI in predicting postoperative pain were 44 (sensitivity: 84%, specificity: 53%) and 63 (sensitivity: 52%, specificity: 82%), respectively, which are different from those suggested by their respective manufacturers for use in intraoperative state under general anaesthesia. The cut-off values of SPI and ANI for detecting pain were similar regardless of the type of anesthesia.


Assuntos
Analgesia , Nociceptividade , Anestesia Geral , Humanos , Dor Pós-Operatória/diagnóstico , Estudos Prospectivos
2.
Cell Death Differ ; 26(2): 245-259, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-29786073

RESUMO

Cellular senescence refers to an irreversible growth arrest that is triggered by various intrinsic and extrinsic stresses. Many recent studies have demonstrated that cellular senescence plays a crucial role in the regression of tumors exposed to ionizing radiation (IR), but the underlying mechanism remains unknown. Here we show that the activation of integrin ß4 is essential for IR-induced cellular senescence. IR treatment results in the phosphorylation of integrin ß4 at tyrosine residue 1510, leading to activation of the integrin α6ß4-Src-AKT signaling pathway. We further reveal that the IR-induced phosphorylation of integrin ß4 is regulated by the cholesterol content and membrane fluidity. We also find that IR-induced p53-caspase signaling is independent of integrin α6ß4-Src-AKT signaling. Finally, we show that siRNA- or inhibitor-mediated blockade of integrin α6ß4-Src-AKT signaling switches the post-irradiation fate from senescence to apoptosis, under p53 activated condition, in both cancer cells and tumor tissues of xenograft mice. On the basis of our finding that, integrin α6ß4 is specifically activated and acts primarily to induce premature senescence in irradiated cancer cells, we propose that this integrin may be a valuable target and biomarker for radiotherapy.


Assuntos
Apoptose , Senescência Celular , Integrina alfa6beta4/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Radiação Ionizante , Transdução de Sinais , Quinases da Família src/metabolismo , Células A549 , Animais , Biomarcadores Tumorais/metabolismo , Xenoenxertos , Humanos , Integrina beta4/genética , Integrina beta4/metabolismo , Células MCF-7 , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , RNA Interferente Pequeno/farmacologia , Transfecção , Carga Tumoral/genética , Carga Tumoral/efeitos da radiação
3.
Carcinogenesis ; 37(11): 1089-1097, 2016 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-27559112

RESUMO

Aberrant sialylation has long been correlated with human cancer. Increased ST6 Gal I (ß-galactoside α 2, 6 sialyltransferase) and consequently higher levels of cell-surface α 2, 6 sialylation has been associated with human colorectal cancer (CRC) metastasis. We have extensive circumstantial data that sialylation is connected to cancer metastasis, but we do not understand in detail how sialylation can switch on/off multiple steps in cancer metastasis. To investigate the molecular mechanism underlying the ST6Gal I-mediated metastasis of CRC, we silenced the ST6Gal I gene in a metastatic SW620 CRC cell line (SW620-shST6Gal I) and examined the metastatic behavior of the cells. We found that various hallmarks of metastatic ability were considerably enhanced in ST6Gal 1-depleted SW620 clones, as assessed both in vitro and in vivo . In particular, the metastasis suppressor, KAI1, was down-regulated in ST6Gal I-deficient SW620 clones. This reflected the increased exosome-mediated exportation of KAI1, and was associated with a decrease in the KAI1-mediated inhibition of integrin. These findings indicate that gene silencing of ST6Gal I could enhance metastasis of CRC by down-regulating KAI1 activity and rescuing its negative effects on integrin signaling.

4.
J Nat Prod ; 78(8): 2110-5, 2015 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-26280594

RESUMO

This study investigated the agonistic activity of magnesium lithospermate B (1), isolated from Salvia miltiorrhiza, on peroxisome proliferator-activated receptor (PPARß/δ) and the expressions of collagen genes (COL1A1 and COL3A1) and transforming growth factor-ß1 (TGF-ß1) in models of skin aging. The action of compound 1 as a PPARß/δ agonist was determined by reporter gene assay, immunostaining, and Western blotting. To determine the antiaging effects of compound 1 on skin, aged Sprague-Dawley rat skin and ultraviolet B (UVB)-irradiated human skin fibroblasts were used. The results show that 1 presented a marked enhancement of both nuclear protein levels and activity of PPARß/δ in fibroblasts. In addition, 1 prevented downregulation of PPARß/δ activity in aged rat skin and UVB-induced fibroblasts. Furthermore, 1 increased the expressions of COL1A1, COL3A1, and TGF-ß1 in vivo and in a cell culture system. Therefore, the present study shows that compound 1 prevents collagen degradation in aged rat skin and UVB-exposed fibroblasts through PPARß/δ activation. The therapeutic and cosmetic applications of compound 1 need further investigation.


Assuntos
Colágeno/metabolismo , PPAR delta/metabolismo , PPAR beta/metabolismo , Salvia miltiorrhiza/química , Pele/efeitos dos fármacos , Idoso , Animais , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/metabolismo , Fibroblastos/efeitos dos fármacos , Humanos , Magnésio/metabolismo , Masculino , Estrutura Molecular , NF-kappa B/metabolismo , Ratos , Ratos Sprague-Dawley , Ativação Transcricional , Regulação para Cima
5.
Mol Pharmacol ; 88(4): 708-19, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26219912

RESUMO

Cancer therapies attempt to destroy the entire tumor, but this tends to require toxic compounds and high doses of radiation. Recently, considerable attention has focused on therapy-induced senescence (TIS), which can be induced in cancer cells by low doses of therapeutic drugs or radiation and provides a barrier to tumor development. However, the molecular mechanisms governing TIS remain elusive. Special attention has been paid to the potential chemopreventive effect of aspirin against human colorectal cancer. In this study, we investigated the effects of aspirin on TIS of human colorectal carcinoma (CRC) cells and show that it occurs via sirtuin 1 (SIRT1) and AMP-activated protein kinase (AMPK), two key regulators of cellular metabolism. Aspirin increased the senescence of CRC cells, increased the protein levels of SIRT1, phospho-AMPK (T172), and phospho-acetyl CoA carboxylase (S79), and reduced the cellular level of ATP. Small-interfering RNA-mediated downregulation or pharmacological inhibition of SIRT1 or AMPK significantly attenuated the aspirin-induced cellular senescence in CRC cells. In contrast, treatment with a SIRT1 agonist or an AMP analog induced cellular senescence. Remarkably, SIRT1 knockdown abrogated the aspirin-induced activation of AMPK, and vice versa. During the progression of aspirin-induced cellular senescence in CRC cells, SIRT1 showed increased deacetylase activity at a relatively early time point but was characterized by decreased activity with increased cytoplasmic localization at a later time point. Collectively, these novel findings suggest that aspirin could provide anticancer effects by inducing senescence in human CRC cells through the reciprocal regulation of SIRT1-AMPK pathways.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Aspirina/metabolismo , Senescência Celular/fisiologia , Neoplasias Colorretais/metabolismo , Sistemas de Liberação de Medicamentos/métodos , Sirtuína 1/metabolismo , Aspirina/administração & dosagem , Senescência Celular/efeitos dos fármacos , Células HCT116 , Humanos
6.
J Epilepsy Res ; 5(1): 29-32, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26157673

RESUMO

Anti N-methyl-D-aspartate (NMDA) receptor encephalitis is one of the most common types of autoimmune synaptic encephalitis. Anti-NMDA receptor encephalitis commonly occurs in young women with ovarian teratoma. It has variable clinical manifestations and treatment responses. Sometimes it is misdiagnosed as a psychiatric disorder or viral encephalitis. To the best of our knowledge, anti-NMDA receptor encephalitis is a rare condition in pregnant women. We report a case of anti-NMDA receptor encephalitis in a pregnant woman who presented with abnormal behavior, epileptic seizure, and hypoventilation.

7.
Int J Mol Med ; 35(3): 731-8, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25543718

RESUMO

Radiation-induced heart disease (RIHD) is becoming an increasing concern for patients and clinicians alike due to the use of radiotherapy for the treatment of breast cancer, Hodgkin's lymphoma, pediatric cancer and tumors of the thorax. However, the mechanisms underlying this phenomenon remain largely unknown. As the senescent cell fraction following irradiation is known to increase, in the present study, we investigated whether ionizing radiation (IR) causes the onset of heart disease by inducing cellular senescence in cardiomyocytes. In the present study, we evaluated the effects of IR on HL-1 and H9C2 cells, cells predominantly used in in vitro myocardial cell models. We found that the exposure of the HL-1 and H9C2 cells to IR induced reactive oxygen species (ROS)-mediated cellular senescence, as shown by staining of senescence-associated ß-galactosidase (SA-ß-gal). The levels of ROS in irradiated cells were determined using the fluorescent dye, 2', 7'-dichlorodihydrofluorescein diacetate (DCF-DA). Notably, the expression of corin, a cardiac protease that is essential for the proteolytic cleavage of natriuretic peptides, was significantly decreased following the exposure of the cells to IR. Importantly, the knockdown of corin by RNA interference enhanced IR-induced senescence. On the contrary, the overexpression of natriuretic peptides reversed the IR-induced senescence. Taken together, our data suggest that defects in corin function and the inhibition of natriuretic peptides following exposure to IR may contribute to the development of RIHD through the acceleration of cellular senescence.


Assuntos
Senescência Celular/genética , Senescência Celular/efeitos da radiação , Expressão Gênica , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/efeitos da radiação , Radiação Ionizante , Serina Endopeptidases/genética , Regulação para Baixo , Técnicas de Silenciamento de Genes , Peptídeos Natriuréticos/genética , Espécies Reativas de Oxigênio/metabolismo , Serina Endopeptidases/deficiência
8.
PLoS One ; 9(8): e102689, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25099178

RESUMO

Skin is in direct contact with the environment and therefore undergoes aging as a consequence of environmentally induce damage. Wrinkle formation is a striking feature of intrinsic and photo-induced skin aging, which are both associated with oxidative stress and inflammatory response. The present study was undertaken to identify the mechanisms responsible for the anti-wrinkle effects of MLB, and thus, we investigated whether magnesium lithospermate B (MLB) from Salvia miltiorrhiza BUNGE associated with wrinkle formation caused by intrinsic and extrinsic skin aging using Sprague-Dawley rats aged 5 and 20 months and ultraviolet B (UVB)-irradiated human skin fibroblasts cells, respectively. The results obtained showed that the oral administration of MLB significantly upregulated the level of type I procollagen and downregulated the activities and expressions of matrix-metalloproteinases (MMPs) in rat skin. In fibroblasts, MLB suppressed the transactivation of nuclear factor-kB (NF-kB) and activator protein 1(AP-1), which are the two transcription factors responsible for MMP expression, by suppressing oxidative stress and the mitogen activated protein kinase (MAPK) pathway. Our results show that the antioxidant effect of MLB is due to the direct scavenging of reactive oxygen species (ROS) and its inhibitory effects on NF-kB-dependent inflammation genes, such as, cyclooxygenase-2 and inducible nitric oxide synthase. MLB was found to reverse both age- and UVB-related reductions in skin procollagen levels by suppressing the expressions and activities of NF-kB and AP-1-dependent MMPs by modulating ROS generation and the MAPK signaling pathway. We suggest that MLB potentially has anti-wrinkle and anti-skin aging effects.


Assuntos
Colagenases/metabolismo , Cosméticos/farmacologia , Medicamentos de Ervas Chinesas/farmacologia , Sequestradores de Radicais Livres/farmacologia , NF-kappa B/metabolismo , Salvia miltiorrhiza/química , Transdução de Sinais/efeitos dos fármacos , Envelhecimento da Pele/efeitos dos fármacos , Animais , Colágeno Tipo II/metabolismo , Cosméticos/química , Medicamentos de Ervas Chinesas/química , Sequestradores de Radicais Livres/química , Humanos , Masculino , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos da radiação , Envelhecimento da Pele/patologia , Envelhecimento da Pele/efeitos da radiação , Fator de Transcrição AP-1/metabolismo , Raios Ultravioleta/efeitos adversos
9.
Age (Dordr) ; 36(4): 9679, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25007762

RESUMO

Changes in the activities of FoxOs caused by phosphorylation, acetylation, or ubiquitination induce expressional changes in the genes involved in the modulation of oxidative stress by modifying histones and chromatins and can substantially alter cellular functions during aging and age-related diseases. However, the precise role that FoxO6, a novel member of the FoxO class of transcription factors, plays in the aging kidney has not been determined. The purpose of this study was to determine the role played by FoxO6 in the maintenance of redox homeostasis in HEK293T cells and aged kidney tissues isolated from ad libitum (AL)-fed and 40 % calorie restriction (CR) rats. The results obtained from AL-fed rats showed that diminished FoxO6 activity during aging was caused by FoxO6 phosphorylation, which disabled its transcriptional activity. In contrast, CR rats were found to have significantly higher FoxO6 activities and maintained redox balance. To determine the molecular mechanism responsible for FoxO6 modification by age-related oxidative stress, we examined H2O2-treated HEK293T cells in which FoxO6 was inactivated by phosphorylation and found that H2O2-induced oxidative stress promoted FoxO6 phosphorylation via PI3K/Akt signaling. The results of this study show that the protective role of FoxO6 in the aging process may in part be related to its ability to attenuate oxidative stress by upregulating catalase expression, as shown in CR. This delineation of the role of FoxO6 expands understanding of the pathological and physiological mechanisms of aging.


Assuntos
Envelhecimento/metabolismo , Restrição Calórica/métodos , Fatores de Transcrição Forkhead/metabolismo , Animais , Western Blotting , Células Cultivadas , Modelos Animais de Doenças , Humanos , Imunoprecipitação , Masculino , Fosforilação , Ratos , Ratos Endogâmicos F344
10.
Arch Pharm Res ; 37(4): 539-47, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23888332

RESUMO

The redox sensitive, proinflammatory nuclear transcription factor NF-κB plays a key role in inflammation. In a redox state disrupted by oxidative stress, pro-inflammatory genes are upregulated by the activation of NF-κB via diverse kinases. Thus, the search and characterization of new substances that modulate NF-κB are topics of considerable research interest. Caffeic acid is a component of garlic, some fruits, and coffee, and is widely used as a phenolic agent in beverages. In the present study, caffeic acid was examined with respect to the modulation of inflammatory NF-κB activation via the redox-related c-Src/ERK and NIK/IKK pathways via the reduction of oxidative stress. YPEN-1 cells (an endothelial cell line) were used to explore the molecular mechanism underlying the anti-inflammatory effect of caffeic acid by examining its modulation of NF-κB signaling pathway by LPS. Our results show that LPS-induced oxidative stress-related NF-κB activation upregulated pro-inflammatory COX-2, NF-κB targeting gene which were all inhibited effectively by caffeic acid. Our study shows that caffeic acid inhibits the activation of NF-κB via the c-Src/ERK and NIK/IKK signal transduction pathways. Our results indicate that antioxidative effect of caffeic acid and its restoration of redox balance are responsible for its anti-inflammatory action. Thus, the study provides new information regarding the anti-inflammatory properties of caffeic acid and the roles in the regulation of LPS-induced oxidative stress induces alterations in signal transduction pathways.


Assuntos
Ácidos Cafeicos/farmacologia , Células Endoteliais/efeitos dos fármacos , Quinase I-kappa B/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , NF-kappa B/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Quinases da Família src/metabolismo , Animais , Anti-Inflamatórios/farmacologia , Linhagem Celular , Células Endoteliais/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Lipopolissacarídeos/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Ratos , Regulação para Cima/efeitos dos fármacos , Quinase Induzida por NF-kappaB
11.
PLoS One ; 8(9): e73877, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24066081

RESUMO

Skin aging is a multisystem degenerative process caused by several factors, such as, UV irradiation, stress, and smoke. Furthermore, wrinkle formation is a striking feature of photoaging and is associated with oxidative stress and inflammatory response. In the present study, we investigated whether caffeic acid, S-allyl cysteine, and uracil, which were isolated from garlic, modulate UVB-induced wrinkle formation and effect the expression of matrix-metalloproteinase (MMP) and NF-κB signaling. The results obtained showed that all three compounds significantly inhibited the degradation of type І procollagen and the expressions of MMPs in vivo and attenuated the histological collagen fiber disorder and oxidative stress in vivo. Furthermore, caffeic acid and S-allyl cysteine were found to decrease oxidative stress and inflammation by modulating the activities of NF-κB and AP-1, and uracil exhibited an indirect anti-oxidant effect by suppressing cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) expressions levels and downregulating transcriptional factors. These results suggest that the anti-wrinkle effects of caffeic acid, S-allyl cysteine, and uracil are due to anti-oxidant and/or anti-inflammatory effects. Summarizing, caffeic acid, S-allyl cysteine, and uracil inhibited UVB-induced wrinkle formation by modulating MMP via NF-κB signaling.


Assuntos
Anti-Inflamatórios/uso terapêutico , Alho/química , Metaloproteinases da Matriz/metabolismo , NF-kappa B/metabolismo , Envelhecimento da Pele/efeitos dos fármacos , Animais , Anti-Inflamatórios/química , Ácidos Cafeicos/uso terapêutico , Cisteína/análogos & derivados , Cisteína/uso terapêutico , Masculino , Camundongos , Estresse Oxidativo/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/efeitos da radiação , Envelhecimento da Pele/efeitos da radiação , Raios Ultravioleta , Uracila/uso terapêutico
12.
Food Chem Toxicol ; 49(9): 2273-8, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21722695

RESUMO

Although the nutritional composition and health status after consumption of the meat and milk derived from both conventionally bred (normal) and somatic cell nuclear transferred (cloned) animals and their progeny are not different, little is known about their food safeties like genetic toxicity. This study is performed to examine both in vitro (bacterial mutation and chromosome aberration) and in vivo (micronucleus) genotoxicity studies of cloned cattle meat. The concentrations of both normal and cloned cattle meat extracts (0-10×) were tested to five strains of bacteria (Salmonella typhimurium: TA98, TA100, TA1535, and TA1537; Escherichia coli: WP2uvrA) for bacterial mutation and to Chinese hamster lung (CHL/IU) cells for chromosome aberration, respectively. For micronucleus test, ICR mice were divided into five dietary groups: commercial pellets (control), pellets containing 5% (N-5) and 10% (N-10) normal cattle meat, and pellets containing 5% (C-5) and 10% (C-10) cloned cattle meat. No test substance-related genotoxicity was noted in the five bacterial strains, CHL/IU cells, or mouse bone marrow cells, suggesting that the cloned cattle meat potentially may be safe in terms of mutagenic hazards. Thus, it can be postulated that the cloned cattle meat do not induce any harmful genotoxic effects in vitro and in vivo.


Assuntos
Clonagem de Organismos , Carne , Técnicas de Transferência Nuclear , Animais , Bovinos , Aberrações Cromossômicas , Técnicas In Vitro , Camundongos , Testes de Mutagenicidade
13.
J Nanosci Nanotechnol ; 11(2): 1710-3, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21456273

RESUMO

Mesoporous V2O5/TiO2 particles were prepared by spray pyrolysis and applied to the catalytic oxidation of 1,2-dichlorobenzene (1,2-DCB). Two different precursors (alkoxide and nanoparticles) for the TiO2 support were used to determine the effects on the texture properties and the catalytic activity of the mesoporous V2O5/TiO2 particles. The 5 wt% V2O5/TiO2 particles had the largest surface area (173 m2/g) and 4.7 nm in average pore size. The catalytic activity of the V2O5/TiO2 particles depended strongly on the loading quantity of vanadium, whereas the P25-derived samples showed no significant change in catalytic activity with weight% of vanadium. The surface area of the V2O5/TiO2 particles prepared using the alkoxide precursor was larger than that of the particles prepared using P25 nanoparticles. The P25-derived V2O5/TiO2 particles, however, showed a higher catalytic activity compared with those alkoxide-derived, which is due to the difference in the vanadium quantity exposed to the pore surface. It was confirmed that the 10 wt% V2O5/TiO2 particles prepared by spray pyrolysis had an excellent activity for the oxidation of 1,2-DCB, particularly at temperatures below 300 degrees C.

14.
Toxicol Res ; 26(3): 193-201, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24278524

RESUMO

Hepatic fibrosis represents the main complication of most chronic liver disorders and, regardless of its etiology, is characterized by excessive deposition of extracellular matrix components. In this study, we examined that 1-O-Hexyl-2,3,5-Trimethylhydroquinone (HTHQ) , a potent anti-oxidative agent, could prevent experimental hepatic fibrosis induced by dimethylnitrosamine (DMN) in male SD rats. Except for vehicle control group, other groups were induced hepatic fibrosis by intraperitoneal injection with DMN (10 mg/ml/kg) on 3 consecutive days weekly for 4 weeks. During the same 4 weeks, control and DMN groups were given vehicle and HTHQ 50, 100 and 200 groups were orally administered HTHQ (50, 100, 200 mg/kg respectively) . In HTHQ 100 and 200 groups, relative liver weight and serum chemistry level improved significantly. HTHQ reduced hydroxyproline (p < 0.05) and malondialdehyde (p < 0.05) level in the liver. Histopathological examination of H&E, Masson's trichrome stain showed the reduced fibrotic septa in HTHQ 100 and 200 groups. HTHQ administration showed reduced mRNA level of PDGF (Plateletderived growth factor) , α-SMA (α-smooth muscle actin) and TGF-ß (transforming growth factor-ß) than DMN-induced hepetic fibrosis animals in the liver tissue. In this study, we showed that HTHQ improves against DMN-induced liver fibrosis in male SD rats.

15.
Toxicology ; 187(1): 67-73, 2003 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-12679053

RESUMO

Carbon tetrachloride (CCl(4)) is a toxic material known to induce lipid peroxidation and liver damage. To determine if chitosan has antioxidative effects on CCl(4)-induced liver injury, we administered 1 ml/kg of CCl(4) resolved in a 50% corn oil solution to rats every week by intraperitoneal injection. Chitosan (200 mg/kg body weight per day, MW 380,000 Da) was administered to the CCl(4) + chitosan treated rats by oral gavage during the experimental period. Chitosan significantly decreased liver thiobarbituric acid reactive substances (TBARS) and increased antioxidant enzyme activities (catalase and superoxide dismutase (SOD)). Fatty acid composition was not remarkably changed by chitosan; only arachidonic acid (20:4n-6) levels were significantly altered by CCl(4). Chitosan administration in the present experiment did not restore the decreased delta5-desaturase activity. In addition, chitosan supplementation did not prevent the CCl(4) induced degradation of CYP2E1. In conclusion, our results suggest that chitosan has antioxidative but not detoxifying effects on chronic CCl(4) induced hepatic injury in rats.


Assuntos
Antioxidantes/uso terapêutico , Intoxicação por Tetracloreto de Carbono/tratamento farmacológico , Quitina/análogos & derivados , Quitina/uso terapêutico , Fígado/efeitos dos fármacos , Microssomos Hepáticos/efeitos dos fármacos , Administração Oral , Animais , Antioxidantes/administração & dosagem , Peso Corporal/efeitos dos fármacos , Intoxicação por Tetracloreto de Carbono/enzimologia , Intoxicação por Tetracloreto de Carbono/metabolismo , Catalase/metabolismo , Quitina/administração & dosagem , Quitosana , Citocromo P-450 CYP2E1/biossíntese , Modelos Animais de Doenças , Injeções Intraperitoneais , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/patologia , Masculino , Microssomos Hepáticos/enzimologia , Microssomos Hepáticos/metabolismo , Tamanho do Órgão/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Substâncias Reativas com Ácido Tiobarbitúrico/análise
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