RESUMO
BACKGROUND AND PURPOSE: Cyclooxygenase 2 (COX-2) is involved in inflammatory bowel disease, but the effect of flavonoids at the intestinal epithelial level is unknown. We aimed to characterize the effect and structure-activity relationship of nine selected flavonoids on COX-2 expression in intestinal epithelial cell (IEC)18 cells. We also investigated the signal transduction pathway(s) responsible for the effects observed. EXPERIMENTAL APPROACH: Intestinal epithelial cell 18, a non-tumour cell line with intestinal epithelial phenotype, was used. COX-2 was measured by Western blot and the involvement of the NF-kappaB pathway assessed by Western blot, pharmacological inhibition, luciferase reporter assays and nuclear translocation experiments. KEY RESULTS: The effect of flavonoids on COX-2 expression depended on the experimental conditions tested [non-stimulated and lipopolysaccharide (LPS)-stimulated]. Flavonoids caused an increase in COX-2 expression and NF-kappaB-dependent gene transcription under basal conditions. Conversely, under LPS stimulation flavonoids increased, decreased or did not affect COX-2 levels depending on the specific type. Variable effects were observed on extracellular signal regulated kinase/p38/c-Jun N-terminal kinase phosphorylation and p50/65 nuclear translocation. CONCLUSION AND IMPLICATIONS: The effect of flavonoids on COX-2 expression depended on the balance of the interference with IkappaB-alpha phosphorylation and other signalling targets, and therefore depends on the experimental conditions and on the type of flavonoids. This is expected to result in different effects in inflammatory conditions. In general, flavonoids may limit epithelial COX-2 expression in inflammatory conditions while favouring it when inflammation is not present.
Assuntos
Inibidores de Ciclo-Oxigenase 2/farmacologia , Ciclo-Oxigenase 2/metabolismo , Células Epiteliais/efeitos dos fármacos , Flavonoides/farmacologia , Mucosa Intestinal/efeitos dos fármacos , NF-kappa B/antagonistas & inibidores , Animais , Western Blotting , Linhagem Celular , Núcleo Celular/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Ciclo-Oxigenase 2/biossíntese , Inibidores de Ciclo-Oxigenase 2/química , Relação Dose-Resposta a Droga , Células Epiteliais/enzimologia , Células Epiteliais/imunologia , Flavonoides/química , Mucosa Intestinal/citologia , Mucosa Intestinal/enzimologia , Mucosa Intestinal/imunologia , L-Lactato Desidrogenase/metabolismo , Lipopolissacarídeos/farmacologia , Luciferases/genética , Estrutura Molecular , NF-kappa B/genética , NF-kappa B/metabolismo , Plasmídeos , Transporte Proteico , RatosRESUMO
This work provides a novel, highly sensitive, hot start PCR method for rapid and specific detection of African swine fever virus (ASFV) that can be used as a routine diagnostic test for ASFV in surveillance, control, and eradication programs. A confirmatory test of the specificity of this method based on restriction endonuclease analysis was also developed.
