In vitro enhancement of the mutagenicity of 4-nitro-o-phenylenediamine by plant S-9.

J M Gentile, G J Gentile, S Townsend, M J Plewa

Index: Environ. Mutagen. 7(1) , 73-85, (1985)

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Abstract

The direct-acting mutagen 4-nitro-o-phenylenediamine (NOP) was activated in vitro by pea or tobacco S-9 into a more potent mutagen in Salmonella typhimurium strain TA98. NOP mutagenicity was not altered by Aroclor 1254-induced rat liver S-9. The plant S-9 activation of NOP was heat-sensitive but was not NADPH-dependent, did not involve superoxide radicals, and was not inhibited by CO. A direct relationship between plant peroxidase and NOP activation was established. Several purified peroxidases including horseradish peroxidase, chloroperoxidase, and lactoperoxidase also activated NOP. The perodoxidative process was not H2O2-dependent but was partially inhibited by a peroxidase inhibitor.