RESUMEN
BACKGROUND: Black tea has been shown to elicit anti-oxidant, anti-carcinogenic, anti-inflammatory and anti-mutagenic properties. In this study, we investigated the impact of black tea extract (BTE) on lipopolysaccharide (LPS)-induced NF-κB signaling in bone marrow derived-macrophages (BMM) and determined the therapeutic efficacy of this extract on colon inflammation. METHODS: The effect of BTE on LPS-induced NF-κB signaling and pro-inflammatory gene expression was evaluated by RT-PCR, Western blotting, immunofluorescence and electrophoretic mobility shift assay (EMSA). The in vivo efficacy of BTE was assessed in mice with 3% dextran sulfate sodium (DSS)-induced colitis. The severity of colitis was measured by weight loss, colon length and histologic scores. RESULTS: LPS-induced IL-12p40, IL-23p19, IL-6 and IL-1ß mRNA expressions were inhibited by BTE. LPS-induced IκBα phosphorylation/degradation and nuclear translocation of NF-κB/p65 were blocked by BTE. BTE treatment blocked LPS-induced DNA-binding activity of NF-κB. BTE-fed, DSS-exposed mice showed the less weight loss, longer colon length and lower histologic score compared to control diet-fed, DSS-exposed mice. DSS-induced IκBα phosphorylation/degradation and phosphorylation of NF-κB/p65 were blocked by BTE. An increase of cleaved caspase-3 and poly (ADP-ribose) polymerase (PARP) in DSS-exposed mice was blocked by BTE. CONCLUSIONS: These results indicate that BTE attenuates colon inflammation through the blockage of NF-κB signaling and apoptosis in DSS-induced experimental colitis model.
Asunto(s)
Camellia sinensis/química , Colitis/tratamiento farmacológico , Regulación hacia Abajo/efectos de los fármacos , Lipopolisacáridos/inmunología , FN-kappa B/inmunología , Extractos Vegetales/farmacología , Transducción de Señal/efectos de los fármacos , Animales , Células Cultivadas , Colitis/inducido químicamente , Colitis/genética , Colitis/inmunología , Citocinas/genética , Citocinas/inmunología , Sulfato de Dextran/efectos adversos , Modelos Animales de Enfermedad , Expresión Génica/efectos de los fármacos , Humanos , Macrófagos/efectos de los fármacos , Macrófagos/inmunología , Ratones , Ratones Endogámicos C57BLRESUMEN
OBJECTIVE: The aim of this study was to determine the impact of the black tea polyphenol, theaflavin, on the expression of adhesion molecules and activation of lipopolysaccharide (LPS)-induced innate signaling in rat intestinal epithelial (RIE) cells. METHODS: The effect of theaflavin on neutrophil adhesion, expression of intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1, LPS-induced nuclear factor-kappa B (NF-κB), and mitogen-activated protein kinase (MAPK) signaling was examined by neutrophil adhesion assay, RT-PCR, Western blotting, immunofluorescence, and electrophoretic mobility shift assay (EMSA). RESULTS: Theaflavin suppressed adhesion of neutrophils to LPS-stimulated RIE cells. LPS-induced ICAM-1 and VCAM-1 expressions were inhibited by theaflavin. LPS-induced IκBα phosphorylation/degradation and nuclear translocation of NF-κB/p65 were blocked by theaflavin. Also, theaflavin blocked NF-κB DNA-binding activity in EMSA. LPS-induced phosphorylation of JNK was inhibited by theaflavin. Bay11-7082 (a NF-κB inhibitor) and SP600125 (a JNK inhibitor) suppressed the LPS-induced ICAM-1 and VCAM-1 mRNA accumulations. CONCLUSIONS: These results indicate that black tea polyphenol theaflavin suppresses LPS-induced ICAM-1 and VCAM-1 expressions through blockage of NF-κB and JNK activation in intestinal epithelial cells.
Asunto(s)
Biflavonoides/farmacología , Catequina/farmacología , Células Epiteliales/metabolismo , Flavonoides/química , Molécula 1 de Adhesión Intercelular/metabolismo , Intestinos/citología , Lipopolisacáridos/metabolismo , MAP Quinasa Quinasa 4/metabolismo , FN-kappa B/metabolismo , Fenoles/química , Molécula 1 de Adhesión Celular Vascular/metabolismo , Animales , Inhibidores Enzimáticos/farmacología , Sistema de Señalización de MAP Quinasas , Polifenoles , Ratas , Transducción de Señal , TéRESUMEN
The protective effect of Acanthopanax senticosus (AS) against ethanol (EtOH)-induced apoptosis of the human neuroblastoma cell line SK-N-MC was investigated via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, flow cytometric analysis, DNA fragmentation assay, reverse transcription-polymerase chain reaction (RT-PCR), and caspase-3 assay. It was shown that cells treated with EtOH exhibit classical apoptotic features, while cells pre-treated with Acanthopanax senticosus prior to EtOH exposure showed decreased occurrence of apoptotic features. In addition, Acanthopanax senticosus pre-treatment was shown to inhibit EtOH-induced increase in caspase-3 mRNA expression and activity. These results suggest that Acanthopanax senticosus may exert a protective effect against EtOH-induced apoptosis of human neuroblastoma cells.