Cjm. Rompelberg et al., EFFECT OF EUGENOL ON THE GENOTOXICITY OF ESTABLISHED MUTAGENS IN THE LIVER, Food and chemical toxicology, 34(1), 1996, pp. 33-42
The influence of in vivo treatment with eugenol on established mutagen
s was studied to determine whether eugenol has antigenotoxic potential
. The effects of eugenol in rats was investigated in the unscheduled D
NA synthesis (UDS) assay with established mutagens and the Salmonella
typhimurium mutagenicity assay. In addition, the effect of in vitro tr
eatment with eugenol on benzo[a]pyrene (B[a]P)-induced genotoxicity in
human hepatoma cell line Hep G2 was investigated in the single-cell g
el electrophoresis assay. The mutagenicity of B[a]P in the S. typhimur
ium mutagenicity assay was lower in liver S-9 fractions prepared from
rats treated with eugenol orally (1000 mg/kg body weight) than in live
r S-9 fractions from control rats. Incubation of liver S-9 fractions f
rom eugenol-treated rats with dimethylbenzanthracene (DMBA) had no ant
imutagenic effect. Eugenol did not modify UDS activity in hepatocytes
isolated from rats pretreated with eugenol orally after exposure of th
ese cells in vitro to DMBA and aflatoxin B-1. Four different treatment
schemes of combinations of B[a]P and eugenol were examined in Hep G2
cells: pre-treatment with eugenol; simultaneous treatment with eugenol
and B[a]P; a combination of these (pretreatment/simultaneous treatmen
t); and post-treatment with eugenol. An increase in the genotoxicity o
f B[a]P was found in Hep G2 cells. No effect of eugenol on the genotox
icity of B[a]P was found with the pre- and post-treatments. It is conc
luded that the effect of eugenol on genotoxicity induced by establishe
d mutagens is not univocal: in vivo treatment of rats with eugenol res
ulted in a reduction of the mutagenicity of B[a]P in the S. typhimuriu
m mutagenicity assay, while in the UDS assay no effect of eugenol was
found. In vitro treatment of cultured cells with eugenol resulted in a
n increase in genotoxicity of B[a]P. These findings indicate that ther
e is only limited support for the antigenotoxic potential of eugenol i
n vivo.