Effect of intestinal microfloras from vegetarians and meat eaters on the genotoxicity of 2-amino-3-methylimidazo[4,5-f]quinoline, a carcinogenic heterocyclic amine.

Aim of this study was to investigate the impact of intestinal microfloras from vegetarians and non-vegetarians on the DNA-damaging activity of 2-amino-3-methyl-3H-imidazo[4,5-f]quinoline (IQ), a carcinogenic heterocyclic amine that is found in fried meats. Floras from four vegetarians (Seventh Day Adventists) and from four individuals who consumed high amounts of meats were collected and inoculated into germfree F344 rats. The rats were kept on isocaloric diets that either contained animal derived protein and fat (meat consumers group) or proteins and fat of plant origin (vegetarian groups).

Determination of heterocyclic aromatic amines in beef extract, cooked meat and rat urine by liquid chromatography with coulometric electrode array detection.

This paper describes a method for the determination of heterocyclic aromatic amines (HAs; DMIP, IQ, MeIQ, MeIQx, 4,8-DiMeIQx, 7,8-DiMeIQx, AalphaC, PhIP) by high-performance liquid chromatography (HPLC) with coulometric electrode array detection. The compounds are separated on reversed phase columns (LiChroCart Superspher 60 RP-select B, 250 mm x 2 mm, 4 microm and LiChrospher 60 RP-select B, 250 mm x 4 mm, 5 microm) using mobile phases consisting of acetonitrile/buffer/distilled water and detected at eight working electrodes at potentials between +190 and +680 mV against modified palladium electrodes. In the context of an EU-interlaboratory exercise, the method was applied to analyse a standardised test solution and--after isolation of the analytes by several clean-up steps--for the analysis of standardised beef extract and grilled meat.

Prevention of heterocyclic amine-induced DNA damage in colon and liver of rats by different lactobacillus strains.

The aim of the present study was to investigate the impact of four different lactobacillus (LB) strains, namely Lactobacillus bulgaricus 291, Streptococcus thermophilus F4, S.thermophilus V3 and Bifidobacterium longum BB536, which are used for the production of yogurt, on the DNA-damaging effects of heterocyclic aromatic amines (HCAs). Male F344 rats were treated orally with HCA mixtures containing 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine, 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline, 2-amino-3,4,8-trimethyl-3H-imidazo[4,5-f]quinoxaline, 2-amino-9H-pyrido[2,3-b]indole and 2-amino-3-methyl-3H- imidazo[4,5-f]quinoline, which were representative of the HCA contents found in fried beef ('beef mix') and chicken ('chicken mix').

Fumonisin B(1) is genotoxic in human derived hepatoma (HepG2) cells.

Fumonisin B(1) (FB(1)), a widespread Fusarium toxin which is frequently found in corn, causes liver tumors in laboratory rodents and is a suspected human carcinogen. The compound was tested in micronucleus (MN) and single cell gel electrophoresis (SCGE) assays in human derived hepatoma (HepG2) cells and caused a pronounced dose-dependent genotoxic effect at exposure concentrations > or = 25 microg/ml. In contrast, no induction of his(+) revertants was found in Salmonella microsome assays with strains TA98, TA100, TA102, TA1535 and TA1537 upon addition of HepG2-derived enzyme (S9) mix in liquid incubation assays with identical exposure concentrations.