The anti-mutagenic and antioxidant effects of bile pigments in the Ames Salmonella test.
The aim of this study was to explore the potential pro- and anti-mutagenic effects of endogenous bile pigments unconjugated bilirubin (BR), biliverdin (BV) and a synthetic, water soluble conjugate, bilirubin ditaurate (BRT) in the Ames Salmonella test. The bile pigments were tested over a wide concentration range (0.01-2 micromol/plate) in the presence of three bacterial strains (TA98, TA100, TA102). A variety of mutagens including benzo[alpha]pyrene (B[alpha]P), 2,4,7 trinitrofluorenone (TNFone), 2-aminofluorene (2-AF), sodium azide (NaN(3)) and tertiary-butyl hydroperoxide (t-BuOOH), were used to promote the formation of mutant revertants. Tests were conducted with (B[alpha]P, 2-AF, t-BuOOH) and without (TNFone, NaN(3), t-BuOOH) metabolic activation incorporating the addition of the microsomal liver preparation, S9. The bile pigments alone did not induce mutagenicity in any of the strains tested (p>0.05). Anti-mutagenic effects of the bile pigments were observed in the presence of all mutagens except for NaN(3) and the anti-mutagenic effects appeared independent of the strain tested. For TNFone induced genotoxicity, the order of effectiveness was BR> or =BRT>BV. However, the order was BV> or =BRT> or =BR for 2-AF. Antioxidant testing in the TA102 strain revealed bile pigments could effectively inhibit the genotoxic effect of t-BuOOH induced oxidative stress. The apparent antioxidant and anti-mutagenic behaviour of bile pigments further suggests their presence in biological systems is of possible physiological importance.
Bulmer
A C
AC
School of Human Movement Studies, University of Queensland, Brisbane 4072, Australia. abulmer@hms.uq.edu.au
Ried
K
K
Coombes
J S
JS
Blanchfield
J T
JT
Toth
I
I
Wagner
K-H
KH
D000818:Animals; D016587:Antimutagenic Agents / Q000737:chemistry / Q000494:pharmacology*; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D001654:Bile Pigments / Q000737:chemistry / Q000494:pharmacology*; D066298:In Vitro Techniques; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism; D009152:Mutagenicity Tests / Q000379:methods; D009153:Mutagens / Q000633:toxicity; D051381:Rats; D012486:Salmonella typhimurium / Q000187:drug effects / Q000235:genetics / Q000378:metabolism
D016587:Antimutagenic Agents; D000975:Antioxidants; D001654:Bile Pigments; D009153:Mutagens