Inhibition of PhIP mutagenicity by catechins, and by theaflavins and gallate esters.
Aqueous solutions of gallic acid, methyl gallate, catechins, theaflavins and tannic acid were tested for inhibition of the mutagenicity of PhIP in the Salmonella typhimurium TA98 assay with an S9 fraction from the liver of rats induced with alpha-naphthoflavone and phenobarbital. The IC50S were in the 80-250 microM range for the gallated catechins, theaflavins and tannic acid. No inhibition could be found with these compounds when a direct acting mutagen was used. This indicates that the anti-mutagenic properties of these phenolic compounds may be due to their inhibition of the cytochrome P-450 enzymes.
Apostolides
Z
Z
Department of Biochemistry, University of Pretoria, South Africa.
Balentine
D A
DA
Harbowy
M E
ME
Hara
Y
Y
Weisburger
J H
JH
D000818:Animals; D016587:Antimutagenic Agents / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology; D001571:Benzoflavones / Q000494:pharmacology; D044946:Biflavonoids; D001711:Biotransformation; D002392:Catechin / Q000494:pharmacology*; D005707:Gallic Acid / Q000031:analogs & derivatives / Q000494:pharmacology*; D047348:Hydrolyzable Tannins / Q000494:pharmacology*; D007093:Imidazoles / Q000494:pharmacology*; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism; D009152:Mutagenicity Tests; D009153:Mutagens / Q000494:pharmacology*; D010634:Phenobarbital / Q000494:pharmacology; D010936:Plant Extracts / Q000494:pharmacology; D051381:Rats; D011916:Rats, Inbred F344; D012486:Salmonella typhimurium / Q000187:drug effects
D016587:Antimutagenic Agents; D000975:Antioxidants; D001571:Benzoflavones; D044946:Biflavonoids; D047348:Hydrolyzable Tannins; D007093:Imidazoles; D009153:Mutagens; D010936:Plant Extracts; C056068:theaflavin; C011512:alpha-naphthoflavone; C052082:methyl gallate; D005707:Gallic Acid; D002392:Catechin; C049584:2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine; D010634:Phenobarbital