Modifying role of trace elements on the mutagenicity of benzo[a]pyrene

Benzo[a]pyrene (BaP) is a polycyclic aromatic hydrocarbon that is found in tobacco smoke and various environmental contaminants and has been shown to be carcinogenic and mutagenic in animal and cell culture studies, respectively. Research studies suggest that various nutritional factors such as the antioxidant vitamins and selenium are very promising as potential anticarcinogenic agents. Moreover, some evidence exists showing that both iron and germanium, at specific dosage levels, may possess antimutagenic potential. This study examined the influence of ferrous sulfate and germanium oxide, independently, upon the mutagenic potential of BaP in the Ames test. Four test strains of Salmonella typhimurium were exposed to BaP (15 micrograms/plate) in the presence of different dosage levels of iron (0-1000 micrograms/plate) and germanium (0-600 micrograms/plate). In the case of iron, it was observed that, depending upon the strain tested, iron reduced BaP's mutagenicity. In strain TA98, this was a significant effect at 100 micrograms/plate and higher. In strains TA97a and TA100, iron concentrations had to reach 250 micrograms/plate or higher to produce significant effects. Iron was much less effective in reducing BaP mutagenicity in strain TA102. In general, germanium was not as effective in reducing the mutagenic potential of BaP. Only in the case of the highest concentrations tested (400 and 600 micrograms/plate) was any effect noted, and this in only three of the four strains evaluated.