Mutagenesis. 1998 Jul;13(4):385-9.  

Inhibition of metabolic activation of the promutagens, benzo[a]pyrene,
2-aminofluorene and 2-aminoanthracene by furanochromones in Salmonella
typhimurium.

Schimmer O, Rauch P.

Institut fur Botanik und Pharmazeutische Biologie, Universitat
Erlangen-Nurnberg, Germany.

Khellin, a naturally occurring furanochromone (Ammi visnaga fruits), inhibited
the mutagenicity of the promutagens benzo[a]pyrene, 2-aminofluorene and
2-aminoanthracene in Salmonella typhimurium TA98. The effect varied greatly and
depended on the S9 fraction used. Cytosolic activation of 2-aminoanthracene was
also inhibited. Khellin produced no effect or only weak activity against the
direct acting mutagens 2-nitrofluorene, 4-nitro-o-phenylenediamine,
1-nitropyrene and ethylmethane sulfonate (in TA100). Daunomycin mutagenicity was
inhibited to a greater extent. Visnagin was more toxic, but showed similar
effects. Khellol and its glucoside were inactive against all the mutagens
tested. We conclude that khellin acts as an inhibitor or the microsomal
cytochrome P450 sub-enzymes analogous to the related furanocoumarins and is also
capable of inhibiting cytosolic enzymes. The extract from Ammi visnaga fruits
showed a higher inhibition potency than khellin alone against 2-aminoanthracene,
1-nitropyrene and daunomycin. This might be due to additional inhibitors, e.g.
coumarins, or to the synergistic effects of accompanying compounds.

PMID: 9717176 [PubMed - indexed for MEDLINE]