Effect of tannic acid on rat liver S9 mediated mutagenesis, metabolism and DNA binding of benzo[a]pyrene.
Tannic acid, a naturally occurring plant phenol, inhibited rat liver S9 mediated mutagenesis of benzo[a]pyrene in Salmonella typhimurium by 32-77% at concentrations of 5-50 micrograms/mutagenesis plate. Tannic acid (10-40 microM) had no affect on the formation of organosoluble metabolites of benzo[a]pyrene or of its water-soluble conjugates. It did, however, inhibit benzo[a]pyrene (B[a]P) metabolite binding to calf thymus DNA by 40% at a concentration of 40 microM and inhibited benzo[a]pyrene 7,8-dihydrodiol-9,10-epoxide (BPDE): deoxyguanosine adduct formation in calf thymus DNA by 12-54% at concentrations of 10-40 microM. These results suggest that the antimutagenic effect of tannic acid and inhibition of B[a]P metabolite binding to DNA is by a previously described scavenging mechanism and/or by a DNA-affinity binding mechanism that prevents BPDE interaction with DNA as previously described for ellagic acid.
Vance
R E
RE
Department of Physiology and Pharmacology, Loma Linda University, School of Medicine, CA 92350.
Teel
R W
RW
D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide / Q000378:metabolism; D000818:Animals; D001564:Benzo(a)pyrene / Q000378:metabolism*; D004247:DNA / Q000378:metabolism*; D018736:DNA Adducts; D047348:Hydrolyzable Tannins / Q000494:pharmacology*; D008099:Liver / Q000378:metabolism*; D008297:Male; D009153:Mutagens / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013634:Tannins / Q000494:pharmacology*
D018736:DNA Adducts; D047348:Hydrolyzable Tannins; D009153:Mutagens; D013634:Tannins; C043931:benzo(a)pyrene-7,8-dihydrodiol-9,10-epoxide-DNA; D001564:Benzo(a)pyrene; D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide; D004247:DNA