Expression of DNA repair and metabolic genes in response to a flavonoid-rich diet.
A diet rich in fruit and vegetables can be effective in the reduction of oxidative stress, through the antioxidant effects of phytochemicals and other mechanisms. Protection against the carcinogenic effects of chemicals may also be exerted by an enhancement of detoxification and DNA damage repair mechanisms. To investigate a putative effect of flavonoids, a class of polyphenols, on the regulation of the gene expression of DNA repair and metabolic genes, a 1-month flavonoid-rich diet was administered to thirty healthy male smokers, nine of whom underwent gene expression analysis. We postulated that tobacco smoke is a powerful source of reactive oxygen species. The expression level of twelve genes (APEX, ERCC1, ERCC2, ERCC4, MGMT, OGG1, XPA, XPC, XRCC1, XRCC3, AHR, CYP1A1) was investigated. We found a significant increase (P < 0.001) in flavonoid intake. Urinary phenolic content and anti-mutagenicity did not significantly change after diet, nor was a correlation found between flavonoid intake and urinary phenolic levels or anti-mutagenicity. Phenolic levels showed a significant positive correlation with urinary anti-mutagenicity. AHR levels were significantly reduced after the diet (P = 0.038), whereas the other genes showed a generalized up regulation, significant for XRCC3 gene (P = 0.038). Also in the context of a generalized up regulation of DNA repair genes, we found a non-significant negative correlation between flavonoid intake and the expression of all the DNA repair genes. Larger studies are needed to clarify the possible effects of flavonoids in vivo; our preliminary results could help to better plan new studies on gene expression and diet.
Guarrera
Simonetta
S
Institute for Scientific Interchange Foundation, Section of Life Sciences, viale Settimio Severo 65, Torino, Italy.
Sacerdote
Carlotta
C
Fiorini
Laura
L
Marsala
Rosa
R
Polidoro
Silvia
S
Gamberini
Sara
S
Saletta
Federica
F
Malaveille
Christian
C
Talaska
Glenn
G
Vineis
Paolo
P
Matullo
Giuseppe
G
D000328:Adult; D000975:Antioxidants / Q000378:metabolism; D004249:DNA Damage / Q000235:genetics; D004260:DNA Repair / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics; D004032:Diet; D004435:Eating / Q000502:physiology; D005419:Flavonoids / Q000235:genetics*; D005504:Food Analysis; D005786:Gene Expression Regulation / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009152:Mutagenicity Tests; D010636:Phenols / Q000652:urine; D012907:Smoking / Q000503:physiopathology; D015854:Up-Regulation / Q000235:genetics
D000975:Antioxidants; D004268:DNA-Binding Proteins; D005419:Flavonoids; D010636:Phenols