Red wine and black tea polyphenols modulate the expression of cycloxygenase-2, inducible nitric oxide synthase and glutathione-related enzymes in azoxymethane-induced f344 rat colon tumors.
J Nutr
; 132(6): 1376-9, 2002 Jun.
Article
en En
| MEDLINE
| ID: mdl-12042461
ABSTRACT
Polyphenolic compounds extracted from red wine (WE) and black tea (BT), 50 mg/(kg. d), inhibit the promotion phase of the colon carcinogenesis process induced by azoxymethane (AOM) in rodents. To investigate possible mechanisms of this protective activity, we evaluated by RT-PCR the gene expression of cycloxygenase-2 (COX-2), inducible NO synthase (iNOS), gamma-glutamylcysteine synthetase (gamma-GCS) and two isoforms of glutathione S-transferase (GST), GST-P and GST-M2, in 30 AOM-induced tumors and in the corresponding normal colon mucosa. AOM-induced colon tumors had significantly greater GST-P, GST-M2, COX-2 and iNOS gene expression than the corresponding normal mucosa. However, tumors harvested from rats treated with BT (P < 0.05) and WE (P < 0.01) polyphenols had a lower GST-P mRNA level than tumors from controls. Treatment with WE polyphenols induced a similar inhibitory effect on the colon tumor overexpression of GST-M2 (P < 0.01), COX-2 (P < 0.05) and iNOS (P < 0.05). In the normal mucosa, rats treated with BT polyphenols had greater gamma-GCS expression than controls (P < 0.01). Our results provide evidence that WE and BT polyphenols modulate COX-2, iNOS and glutathione-related gene expression in tumors, suggesting that these compounds have possible chemotherapeutic activity.
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Bases de datos:
MEDLINE
Asunto principal:
Fenoles
/
Polímeros
/
Flavonoides
/
Prostaglandina-Endoperóxido Sintasas
/
Neoplasias del Colon
/
Óxido Nítrico Sintasa
/
Glutatión
/
Isoenzimas
Idioma:
En
Revista:
J Nutr
Año:
2002
Tipo del documento:
Article
País de afiliación:
Italia