Effect of complex polyphenols and tannins from red wine on DNA oxidative damage of rat colon mucosa in vivo.
BACKGROUND
Dietary polyphenols have been reported to have a variety of biological actions, including anti-carcinogenic, antioxidant and anti-inflammatory activities.


OBJECTIVE
In the present study we have evaluated the effect of an oral treatment with complex polyphenols and tannins from red wine and tea on DNA oxidative damage in the rat colon mucosa.


METHODS
Isolated colonocytes were prepared from the colon mucosa of rats treated for ten days with either wine complex polyphenols (57.2 mg/kg/d) or thearubigin (40 mg/kg/d) by oral gavage. Colonocyte oxidative DNA damage was analysed at the single cell level using a modification of the comet assay technique.


RESULTS
The results show that wine complex polyphenols and tannins induce a significant decrease (-62% for pyrimidine and -57% for purine oxidation) in basal DNA oxidative damage in colon mucosal cells without affecting the basal level of single-strand breaks. On the other hand, tea polyphenols, namely a crude extract of thearubigin, did not affect either strand breaks or pyrimidine oxidation in colon mucosal cells.


CONCLUSIONS
Our experiments are the first demonstration that dietary polyphenols can modulate in vivo oxidative damage in the gastrointestinal tract of rodents. These data support the hypothesis that dietary polyphenols might have both a protective and a therapeutic potential in oxidative damage-related pathologies.
Giovannelli
L
L
Dept. of Pharmacology, University of Florence, Italy. lisag@server1.pharm.unifi.it
Testa
G
G
De Filippo
C
C
Cheynier
V
V
Clifford
M N
MN
Dolara
P
P
D000818:Animals; D003106:Colon / Q000187:drug effects / Q000503:physiopathology*; D020552:Comet Assay / Q000379:methods; D004247:DNA / Q000187:drug effects / Q000378:metabolism; D004249:DNA Damage / Q000187:drug effects* / Q000502:physiology; D005419:Flavonoids; D007413:Intestinal Mucosa / Q000187:drug effects / Q000503:physiopathology; D008297:Male; D010084:Oxidation-Reduction / Q000187:drug effects; D010636:Phenols / Q000378:metabolism / Q000494:pharmacology*; D011108:Polymers / Q000378:metabolism / Q000494:pharmacology*; D059808:Polyphenols; D051381:Rats; D011916:Rats, Inbred F344; D013634:Tannins / Q000378:metabolism / Q000494:pharmacology*; D014920:Wine
D005419:Flavonoids; D010636:Phenols; D011108:Polymers; D059808:Polyphenols; D013634:Tannins; D004247:DNA