Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Toxicol Ind Health ; 32(5): 953-60, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-24817434

RESUMO

Hepatic fibrosis is an important outcome of chronic liver injury and results in excess synthesis and accumulation of extracellular matrix (ECM) components. Phyllanthin (PLN) isolated from Phyllanthus amarus exhibits strong antioxidative property and protects HepG2 cells from carbon tetrachloride (CCl4)-induced experimental toxicity. The present study reports the antifibrotic potential of PLN. The in vivo inhibitory effect of PLN on CCl4-mediated lipid peroxidation and important profibrotic mediator transforming growth factor ß1 and on predominant ECM components collagen and fibronectin were also studied. The results show that PLN acts by suppressing the expression of inflammatory cytokine tumor necrosis factor-α and prevents activation of nuclear factor-κB in hepatic tissue. Our study highlights the molecular mechanism responsible for the antifibrotic efficacy of PLN.


Assuntos
Tetracloreto de Carbono/toxicidade , Lignanas/farmacologia , Cirrose Hepática/tratamento farmacológico , Estresse Oxidativo/efeitos dos fármacos , Transdução de Sinais , Animais , Antioxidantes/farmacologia , Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Regulação para Baixo , Feminino , Células Hep G2 , Humanos , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/citologia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Cirrose Hepática/induzido quimicamente , Camundongos , NF-kappa B/genética , NF-kappa B/metabolismo , Phyllanthus/química , Extratos Vegetais/farmacologia , Substâncias Protetoras/farmacologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fator de Crescimento Transformador beta1/genética , Fator de Crescimento Transformador beta1/metabolismo , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo
2.
Toxicol Mech Methods ; 25(9): 708-17, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26337812

RESUMO

Chronic injury to liver triggers synthesis of extracellular matrix components resulting in progressive fibrosis and eventually cirrhosis. Transforming growth factor-ß1 (TGF-ß1) transduces its signal by binding to TGF-ß type 1 receptor kinase or activin like kinase (ALK5) receptor and mediates hepatic fibrosis by increasing the transcription of downstream entities such as collagen via Smad2 and Smad3. The present study was carried out to investigate the mechanism by which phyllanthin, a hepatoprotective lignin isolated from the plant Phyllanthus amarus (P. amarus) exerts its anti-fibrotic effect. The inhibitory role of phyllanthin on ALK5 was first analyzed using molecular docking experiments. Phyllanthin was found to effectively bind to serine (Ser) 280 at the active site of ALK5 by forming hydrogen bonds. The in vivo protective effect of phyllanthin against carbon tetrachloride (CCl4)-induced hepatic fibrosis was established by studying the protein expressions of TGF-ß1, ALK5 and Smad2 and 3 and by determining various biochemical and histopathological parameters. Phyllanthin was found to exert its anti-fibrotic effect by down-regulating TGF signaling pathway via ALK5 and Smad2 and 3 inhibition.


Assuntos
Tetracloreto de Carbono/toxicidade , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Lignanas/uso terapêutico , Cirrose Hepática/prevenção & controle , Substâncias Protetoras/uso terapêutico , Proteínas Serina-Treonina Quinases/metabolismo , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Alanina Transaminase/sangue , Animais , Aspartato Aminotransferases/sangue , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/patologia , Colágeno/metabolismo , Feminino , Lignanas/administração & dosagem , Lignanas/isolamento & purificação , Cirrose Hepática/induzido quimicamente , Cirrose Hepática/metabolismo , Cirrose Hepática/patologia , Testes de Função Hepática , Camundongos , Simulação de Acoplamento Molecular , Phyllanthus/química , Substâncias Protetoras/administração & dosagem , Substâncias Protetoras/isolamento & purificação , Ligação Proteica , Proteínas Serina-Treonina Quinases/genética , Receptor do Fator de Crescimento Transformador beta Tipo I , Receptores de Fatores de Crescimento Transformadores beta/genética , Proteína Smad2/genética , Proteína Smad3/genética , Fator de Crescimento Transformador beta1/genética
3.
J Clin Exp Hepatol ; 3(1): 29-36, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25755469

RESUMO

BACKGROUND: Aflatoxins are a group of mycotoxins produced by Aspergillus flavus and Aspergillus parasiticus and are potent inducers of hepatotoxicity. OBJECTIVE: The present study was carried out to investigate the effect of black tea infusion on aflatoxin-induced hepatotoxicity in male mice. METHODS: A 2% black tea infusion in drinking water was prepared and orally administered along with aflatoxin (750 and 1500 µg/kg body weight) for 30 days. Morphological investigation, body weight and organ weight calculations and histopathological analysis were carried out. Serum hepatic marker enzymes namely alanine aminotransferase and aspartate aminotransferase were estimated. RESULTS: The results clearly indicated that aflatoxin treatment for 30 days caused significant dose-dependent reduction in body weight and increase in liver weight. The activities of ALT and AST were found to be elevated while protein content was found to be decreased in aflatoxin-treated mice as compared to vehicle control. Histopathological analysis showed hepatocellular necrosis and cytoplasmic vacuolization along with fatty infiltration in toxin-treated animals. Results revealed significant (p < 0.05) restoration of aflatoxin-induced damages in body weight, organ weight, serum chemistry and histopathological features in aflatoxin plus black tea infusion administered mice in a dose dependant manner. CONCLUSION: It is concluded from the present study that supplementation of black tea infusion can be beneficial in positively modulating aflatoxin-induced alterations in liver.

4.
J Ethnopharmacol ; 142(1): 14-22, 2012 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-22521732

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Acalypha indica Linn. (Acalypha indica) vernacularly called Kuppaimeni in Tamil, has been used as a folklore medicine since ages for the treatment of wounds by tribal people of Tamil Nadu, Southern India. The present study investigates the biochemical and molecular rationale behind the healing potential of Acalypha indica on dermal wounds in rats. MATERIAL AND METHODS: Acalypha indica extract (40 mg/kg body weight) was applied topically once a day on full-thickness excision wounds created on rats. The wound tissue was removed and used for estimation of various biochemical and biophysical analyses and to observe histopathological changes with and with-out extract treatment. The serum levels of pro-inflammatory cytokine tumor necrosis factor (TNF-α) was measured at 12 h, 24 h, 48 h and 72 h post-wounding using ELISA. Reverse transcription-polymerase chain reaction (RT-PCR) analysis was performed to study the expression pattern of transforming growth factor [TGF-ß1], collagen 1 α (I) [Col 1 α (I)] and collagen 3 α (I) [Col 3 α (I)]. Likewise, linear incision wounds were created and treated with the extract and used for tensile strength measurements. RESULTS: Wound healing in control rats was characterized by less inflammatory cell infiltration, lack of granulation tissue formation, deficit of collagen and significant decrease in biomechanical strength of wounds. Acalypha indica treatment mitigated the oxidative stress and decreased lipid peroxidation with concomitant increase in ascorbic acid levels. It also improved cellular proliferation, increased TNF-α levels during early stages of wound healing, up-regulated TGF-ß1 and elevated collagen synthesis by markedly increasing the expression of Col 1 α (I) and Col 3 α (I). Increased rates of wound contraction, epithelialization, enhanced shrinkage temperature and high tensile strength were observed in the extract treated rats. CONCLUSION: Acalypha indica extract was shown to augment the process of dermal wound healing by its ability to increase collagen synthesis through up-regulation of key players in different phases of wound healing and by its antioxidative potential.


Assuntos
Colágeno Tipo III/biossíntese , Colágeno Tipo I/biossíntese , Euphorbiaceae , Extratos Vegetais/farmacologia , Cicatrização/efeitos dos fármacos , Administração Cutânea , Animais , Colágeno Tipo I/genética , Colágeno Tipo III/genética , Índia , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Medicina Tradicional , Fitoterapia , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Pele/lesões , Pele/metabolismo , Pele/patologia , Fator de Crescimento Transformador beta1/genética , Fator de Necrose Tumoral alfa/sangue , Regulação para Cima , Cicatrização/fisiologia
5.
J Clin Exp Hepatol ; 1(2): 57-67, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25755316

RESUMO

BACKGROUND: Phyllanthus amarus, a traditional herbal liver-protecting medicine, is known to contain an active ingredient phyllanthin. Many research studies and clinical trials performed in the past using this plant have given contentious results which clearly accentuates the need for the standardization of the extracts. AIM: In this study, P. amarus extract was standardized for phyllanthin content by high performance thin layer chromatography (HPTLC) and high performance liquid chromatography (HPLC) analysis. The preventive role of a standardized extract of P. amarus against CC14-induced hepatotoxicity in vivo and in vitro using mice model and human hepatoma HepG2 cell line, respectively, was investigated. METHODS: Phyllanthin was used as a marker phytochemical for the standardization of P. amarus extract. The extracts were verified for phyllanthin content by HPTLC and HPLC. Female mice were orally administered with CCl4 either with or without standardized P. amarus extract in three different doses. Similarly, the cytoprotective role of the standardized extract in vitro was studied in HepG2 cell line. RESULTS: Oral administration of CCl4 resulted in increased oxidative stress, decreased antioxidative defense, and liver injury. Treatment with P. amarus along with CCl4 significantly mitigated the increase in activities of liver marker enzymes, lipid peroxidation, and bilirubin content. It also increased the antioxidant enzymatic and non-enzymatic defense parameter levels. The results of the in vitro study conducted in HepG2 cells indicated that the hepatotoxin lowered 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (Mil) metabolism and increased the release of transaminases which were corrected with co-incubation with P. amarus. CONCLUSION: The study established a significant liver-protecting role of standardized P. amarus extract due to the presence of active ingredient phyllanthin.

7.
Acta Pol Pharm ; 66(4): 439-44, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19702178

RESUMO

Liver disease has become a global concern worldwide. In absence of reliable liver protective drugs in modem medicine, a large number of medicinal preparations are recommended for the treatment of liver disorders as they are believed to be harmless based on their natural origin. The aim of the present study was to determine the hepatoprotective activity of Phyllanthus amarus plant extract against carbon tetrachloride (CCl4-induced liver damage in female mice. Carbon tetrachloride administration caused a significant increase in liver and serum alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP) and acid phosphatase (ACP), while total protein content significantly decreased as compared to vehicle control. The effect was dose-dependent. Oral administration of aqueous extract of Phyllanthus amarus along with carbon tetrachloride caused significant mitigation of CCl4-induced changes.


Assuntos
Tetracloreto de Carbono/toxicidade , Fígado/efeitos dos fármacos , Phyllanthus , Extratos Vegetais/farmacologia , Alanina Transaminase/sangue , Fosfatase Alcalina/sangue , Animais , Aspartato Aminotransferases/sangue , Feminino , Camundongos
8.
Chem Biol Interact ; 181(3): 351-8, 2009 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-19576190

RESUMO

The present study was an attempt to investigate the hepatoprotective and antioxidative property of Phyllanthus amarus (P. amarus) extract and phyllanthin. Phyllanthin, one of the active lignin present in this plant species was isolated from the aerial parts, by silica gel column chromatography employing gradient elution with hexane-ethyl acetate solvent mixture. It was obtained in high yields (1.23%), compared to reported procedures and the purity was ascertained by HPTLC and reversed-phase HPLC analysis. Characterization of phyllanthin was done by mp, UV-Visible spectrophotometry, elemental analysis, FT-IR, 1H NMR, 13C NMR and mass spectral analysis. Free radical scavenging activity of P. amarus extract and phyllanthin was also examined using DPPH assay. The protective effect of P. amarus extract and phyllanthin was studied on CCl4-induced toxicity in human hepatoma HepG2 cell line. The results indicated that CCl4 treatment caused a significant decrease in cell viability. In addition, the toxin treatment initiated lipid peroxidation (LPO), caused leakage of enzymes like alanine transaminase (ALT) and lactate dehydrogenase (LDH) with a significant decrease in glutathione (GSH) levels. It was observed that phyllanthin effectively alleviated the changes induced by CCl4 in a concentration-dependent manner, with much smaller strengths as compared to P. amarus extract.


Assuntos
Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Intoxicação por Tetracloreto de Carbono/prevenção & controle , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Lignanas/isolamento & purificação , Lignanas/farmacologia , Antioxidantes/química , Linhagem Celular , Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Fina , Humanos , Lignanas/química , Peroxidação de Lipídeos/efeitos dos fármacos , Espectroscopia de Ressonância Magnética , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...