Urinary Mutagenicity Research Articles

Assessment of urinary mutagens presence in a population of non smokers

The paper presents the early results of a study involving a group of 312 non smoking and not professionally exposed subjects (144 males and 168 females) in order to evaluate the probable presence of urinary mutagens possibly derived from aspecific exposures. Urine samples were assayed by the Ames test on the YG1024 Salmonella typhimurium strain in the presence of S9 mix with plate incorporation method with preincubation. At the moment of sample collection, the subjects were invited to fill a questionnaire on their main characteristics and lifestyle. On the basis of laboratory data analysis, it emerged that, on 288 samples with a valuable mutagenic activity, 20 urinary extracts (8 of which were males and 12 were females) showed mutagenicity levels twice as much as spontaneous revertants. Diet and indoor exposure to passive smoking, fireplace and cooking fume exposure seemed to play a major role among the lifestyle behaviours investigated in generating positive mutagenic response with a statistically significant difference between positive and negative samples induction (Chi square, P = 0.0057 and P = 0.0168 respectively). After correction of induced revertants by means of creatinine excretion determination, it appeared that females, who had the higher mean urinary mutagenic activity, showed a mutagenicity level twice as much as men (364 +/- 491 revertants/mmole creatinine for males against 605 +/- 868 revertants/mmole creatinine in females, Mann-Whitney U-test, z = -3.97, P < 0.0001) possibly in consequence of their greater cooking fumes exposure. The study, that carefully evaluated the characteristics of involved subjects, reveals the presence, even though modest, of mutagens in urine of an apparently not significantly exposed population. In addition, standardization of method leads to suppose little feasible a confounding influence of considered features. Moreover, it would be therefore rather interesting to study the effect of low exposure time persistence.

Disposition of Bromodichloromethane in Humans Following Oral and Dermal Exposure

Exposure to bromodichloromethane (BDCM), one of the most prevalent disinfection byproducts in drinking water, can occur via ingestion of water and by dermal absorption and inhalation during activities such as bathing and showering. The objectives of this research were to assess BDCM pharmacokinetics in human volunteers exposed percutaneously and orally to (13)C-BDCM and to evaluate factors that could affect disposition of BDCM. Among study subjects, CYP2E1 activity varied fourfold; 20% had the glutathione S-transferase theta 1-1 homozygous null genotype; and body fat ranged from 7 to 22%. Subjects were exposed to (13)C-BDCM in water (target concentration of 36 mug/l) via ingestion and by forearm submersion. Blood was collected for up to 24 h and analyzed for (13)C-BDCM by solid-phase microextraction and high-resolution GC-MS. Urine was collected before and after exposure for mutagenicity determinations in Salmonella. After ingestion (mean dose = 146 ng/kg), blood (13)C-BDCM concentrations peaked and declined rapidly, returning to levels near or below the limit of detection (LOD) within 4 h. The T(max) for the oral exposure ranged from 5 to 30 min, and the C(max) ranged from 0.4 to 4.1 ng/l. After the 1 h dermal exposure (estimated mean dose = 155 ng/kg), blood concentrations of (13)C-BDCM ranged from 39 to 170 ng/l and decreased to levels near or below the LOD by 24 h. Peak postdose urine mutagenicity levels that were at least twice that of the predose mean level occurred in 6 of 10 percutaneously exposed subjects and 3 of 8 orally exposed subjects. These results demonstrate a highly significant contribution of dermal absorption to circulating levels of BDCM and confirm the much lower oral contribution, indicating that water uses involving dermal contact can lead to much greater systemic BDCM doses than water ingestion. These data will facilitate development and validation of physiologically based pharmacokinetic models for BDCM in humans.

In vivo Antimutagenic Potential of Ginger on Formation and Excretion of Urinary Mutagens in Rats

In vivo Antimutagenic Potential of Ginger on Formation and Excretion of Urinary Mutagens in Rats

Mutagenic activity of overnight urine from healthy non‐smoking subjects

Urinary mutagenicity was evaluated in relation to environmental mutagen exposure (i.e., diet, indoor/outdoor activities, residential area etc.) on the day prior to sample collection, and also considering factors that contribute to the variability of Salmonella mutagenicity assay results. Overnight urine samples from 283 healthy non-smoking residents of northeast Italy (46% males, 20-62 years) were analyzed for mutagenicity on sensitive Salmonella typhimurium strain YG1024 with S9 mix employing the preincubation version of the plate incorporation assay (i.e., the Salmonella reverse mutation test). Urinary mutagenicity varied between 0.02 and 9.84 rev/ equiv. ml, and 7% of samples were positive (i.e., sample elicited a two-fold increase in revertants). There was an evident increase in mutagenicity in subjects with increased intake of mutagen-rich meals (n = 80) (P < 0.01 and positive urine 13% vs. 5%, P = 0.025). Indoor-exposed subjects (n = 65) also showed a higher percentage of positive urine (14% vs. 5%, P = 0.015). In particular, those subjects exposed to cooking fumes the previous evening (n = 28) revealed higher urinary mutagenicity (P = 0.035, positive urine 25% vs. 5%, P < 0.001) than non-indoor exposed. The sources of variability of the mutagenicity assay, mainly the histidine content of the urine concentrate (z = 4.06, P < 0.0001), and to a lesser extent bacterial inoculum size (z = 2.33, P = 0.019), also significantly influenced urinary mutagenicity values. In a linear multiple regression analysis, their effects were still significant (i.e., histidine content P = 0.026 and inoculum size P = 0.021), but the effects of diet, indoor exposure, and other environmental exposures (i.e., traffic and heating system exhausts, residential area) were not. It is concluded that the previous day's exposure to mutagen-rich meals and cooking fumes may influence the presence of mutagenic activity in the overnight urine of non-smoking subjects. This mutagenic activity, which remains in contact with bladder mucosa for several hours, could be considered risk factors for colorectal adenoma and possibly other cancers (i.e., bladder) in non-smokers. Accurate control of histidine content and bacterial inoculum size is strongly recommended when investigating the mutagenic activity of urine from non-smokers.

Comparison of biomarkers in workers exposed to 2,4,6-trinitrotoluene

2,4,6-Trinitrotoluene (TNT) is an important occupational and environmental pollutant. In TNT-exposed humans, notable toxic manifestations have included aplastic anaemia, toxic hepatitis, cataracts, hepatomegaly, and liver cancer. Therefore, methods were developed to biomonitor workers exposed to TNT. The workers were employed in a typical ammunition factory in China. The external dose (air levels and skin exposure), the internal dose (urinary metabolites), the biologically effective dose (haemoglobin adducts, urinary mutagenicity), biological effects (chromosomal aberrations and health effects), and individual susceptibility (genotypes of xenobiotic-metabolizing enzymes) were determined. Haemoglobin-adducts of TNT, 4-amino-2,6-dinitrotoluene (4ADNT) and 2-amino-4,6-dinitrotoluene (2ADNT), and the urinary metabolites of TNT, 4ADNT and 2ADNT, were found in all workers and in some controls. The levels of the haemoglobin-adducts or the urinary metabolites correlated weakly with the skin or air levels of TNT. The urinary mutagenicity determined in a subset of workers correlated strongly with the levels of 4ADNT and 2ADNT in urine. The haemoglobin-adducts correlated moderately with the urinary metabolites and with the urinary mutagenicity. The genotypes of glutathione S-transferases (GSTM1, GSTT1, GSTP1) and N-acetyltransferases (NAT1, NAT2) were determined. In general, the genotypes did not significantly influence the haemoglobin-adduct levels and the urine metabolite levels. However, TNT-exposed workers who carried the NAT1 rapid acetylator genotype showed an increase in urinary mutagenicity and chromosomal aberrations as compared with slow acetylators. The haemoglobin adduct 4ADNT was significantly associated with a risk of hepatomegaly, splenomegaly and cataract; urine metabolites and genotypes were not associated with health effects. These results indicate that a set of well-selected biomarkers may be more informative regarding exposure and effect than routinely performed chemical measurements of pollutants in the air or on the skin.

Evaluation of Urinary Mutagenicity in Azo Dye Manufacture Workers

The aim of the study was to evaluate urinary mutagenicity in workers employed in a major chemical plant located near Rouen (France) that produces dichlorobenzidine and azo dyes. Samples were obtained from 47 male workers aged 38.9+/-11.3 years (range, 21-58 years), mean duration of employment 9.0+/-8.7 years (range, 1-32 years) for urinary mutagenicity determination with use of the Ames fluctuation test (strains TA 98 and TA 100 with and without metabolic activation) and gas chromatography/mass spectrometry. To assess occupational exposure of workers, urine samples were collected in two series. First, initial just after a one-month holiday (non-exposure). Second, four months later during regular occupational activity. During the same periods, workers completed a questionnaire, which sought information concerning their working conditions, non-occupational factors, and personal habits. Of the total 47 samples tested, 3 (6%) collected just after a one-month holiday and 6 (12%) samples collected during regular occupational activity were positive in at least one mutagenicity assay. Dichlorobenzidine traces ranging from 1.6 to 8.9 ppb were detected in 4 (8%) samples of the exposed as well as in 4 (8%) samples of non-exposed workers. No significant differences between biological and analytical responses obtained in the non-exposure period and after occupational exposure were observed, however, 5 (11%) workers in this group presented urinary mutagenicity that could be related to occupational exposure. The study suggests that some industrial hygiene problems, revealed in the analysis of questionnaire responses and confirmed by our evaluation, could be undoubtedly and easily solved to improve working conditions of the employees.

Evaluation of a battery of Salmonella typhimurium tester strains for biomonitoring of mutagenic polycyclic aromatic hydrocarbons, nitroarenes and aromatic amines

Various combinations of Salmonella typhimurium tester strains and S9 mix for bioactivation (TA98 + S9 mix, TA98S; YG1041 + S9 mix, YG1041S) and strain YG1041 in the absence of S9 mix (YG1041) were used to evaluate the mutagenic activity of eight polycyclic aromatic hydrocarbons (PAHs), seven nitroarenes (NAs) and seven aromatic amines (AAs). Three cigarette smoke extracts and two extracts of smokers’ urine (SUE) were also included. Urinary mutagenicity was then determined on 31 individuals, potentially exposed to PAHs, for 0 h, 7 h, 12 h and 24 h. Concentrations of urinary 1-hydroxypyrene (1OHP) and 3-hydroxybenzo[ a]pyrene (3OHBaP), the levels of atmospheric pyrene (Py) and benzo[a]pyrene (BaP), and particulate concentrations in air (AP) were also measured. PAHs could be detected by TA98S and YG1041S, with TA98S being more sensitive than YG1041S. While NAs could be detected by all combinations, YG1041 and YG1041S were more sensitive than TA98S. Although both YG1041S and TA98S could detect AAs, YG1041S was more sensitive than TA98S. Cigarette smoke extract contained mutagenic AAs and NAs, but AAs were the only mutagenic compounds detected in the extracts of smokers’ urine. The concentrations of 1OHP (7 h and 12 h) were significantly higher than those at 0 h, but no difference could be detected with 3OHBaP. Correlations were found between Py and 1OHP (7 h and 24 h) and between BaP and 3OHBaP concentrations (7 h, 12 h and 24 h). A significantly elevated urinary mutagenicity was detected with YG1041S at 7 h in the group of smokers. A good correlation was determined between AP and the test results with TA98S (7 h) and with YG1041 (0 h and 7 h). Urinary 1OHP correlated with the test results with YG1041S (0 h, 7 h and 12 h) while 3OHBaP correlated with those obtained with YG1041S (7 h). Overall, 21/31 individuals were occupationally exposed to AAs, 15/31 individuals were exposed to NAs, and 2/31 were exposed to PAHs as indicated by the Salmonella mutagenicity assay. The urine mutagenicity test was not effective at monitoring occupational exposure to PAHs. However, the correlation with AP implied the presence of unknown mutagenic atmospheric substances that could modulate the urinary mutagenicity.

The influence of environmental exposure to complex mixtures including PAHs and lead on genotoxic effects in children living in Upper Silesia, Poland

Environmental exposure is a complex mixture of hazardous compounds with different mechanisms of toxicity. In case of concomitant exposure to carcinogenic substances--such as polycyclic aromatic hydrocarbons (PAHs)--and to heavy metals--such as lead (Pb)--the level of DNA damage may be enhanced. Children are considered more vulnerable than adults to chemical toxicants because they take in more toxicants as a proportion of body mass and because of inherent biological growth and developmental factors. The objective of the study was to measure cytogenetic effects in Silesian children and to investigate their relation with the environmental exposure to PAHs and Pb. The examined population included 74 children 5-14-year-old who lived in two cities located in the most polluted centre of the Silesia province. Individual exposure to lead was assessed for each child by measuring lead in blood (PbB), and to PAH by measuring 1-hydroxypyrene in urine (1-OHP), urinary mutagenicity and DNA adducts in circulating lymphocytes. Biomarkers of genetic effects were assessed by measuring micronuclei (MN) and sister chromatid exchanges (SCE) in children's peripheral lymphocytes. The mean levels of biomarkers of exposure were as follows: PbB 7.69 microg/dl, DNA adducts 9.59 adducts per 10(8) nt, 1-OHP 0.54 micromol/mol creatinine, and urinary mutagenicity presented as the number of revertants per mmol of creatinine: 485 for TA 98 and 1318 for YG1024. Mean value of MN was 4.44 per 1000 binucleated cells and SCE frequency ranged between 6.24 and 10.06 with a mean value of 7.87. The results suggest the influence of exposure to environmental agents on the induction of cytogenetic effects in peripheral lymphocytes of children: namely Pb on MN and PAHs on SCE. The sources of that exposure may be outdoor and indoor. Emissions from coal-burning stoves are important contributors to the total exposure to PAHs and Pb in Silesian children.

Hazardous Anticancer Drugs in Health Care

Exposure of healthcare workers to anticancer drugs became problematic in the 1970s. Shortly thereafter, studies began documenting exposure of healthcare workers to these drugs. Investigations employing biological markers, such as urine mutagenicity, chromosomal aberrations, sister chromatid exchanges, and micronuclei, demonstrated associations between occupational exposures and elevated marker levels. Other analytical methods emerged to monitor workplaces where drugs were handled. These contemporary studies uncovered widespread contamination of drugs on work surfaces, trace amounts in air samples, and their presence in the urine of workers. Vials containing these drugs are often contaminated with the drug when they are shipped. Most workplace surfaces are contaminated with the drugs being prepared and used in that area. Other anticancer/hazardous drugs would most likely be used in these areas. The interior surfaces of biological safety cabinets and isolators, floors, countertops, carts, storage bins, waste containers, treatment areas, tabletops, chairs, linen, and other items are all potential sources of exposure to anticancer drugs. Patient body fluids contain the drugs and/or metabolites, often more biologically active than the parent compounds. An exposure assessment of areas where anticancer/hazardous drugs are handled must consider every potential source and route of exposure. Data from surface contamination and inhalation studies suggest that dermal exposure is the primary route of exposure. Assessment of exposure is the first step in providing a safe work environment for these workers. However, because of the many drugs to which they are exposed, any assessment can only be an estimation of the overall exposure.

Genotoxic effect of Goeckerman regimen of psoriasis

Goeckerman regimen (GR) of psoriasis includes daily dermal application of crude coal tar (CCT) and dermal exposure to UV-A and UV-B radiation. Observed group consisted of 23 patients with psoriasis treated by GR. Therapeutic ointment contained 5% of CCT. The level of psoriasis area and severity index was significantly decreased after GR (P < 0.001) and confirms high efficiency of GR. High levels of selected metabolites of pyrene and phenanthrene indicated high level of dermal penetration. We found significantly increased urinary mutagenicity in samples collected in the middle and in the end of GR (TA98+S9, P < 0.01; YG1041-S9, P < 0.001; YG1041+S9, P < 0.001). Significant increasing of chromosomal aberrations in peripheral lymphocytes (CA) in blood samples collected in the end of GR (P < 0.001) and consecutive decreasing of CA in 78th day after the end of GR has been observed. Almost all results indicated that the patients could be endangered by a peak genotoxic exposure. Nevertheless, the genotoxic effect does not seem to be long lasting. Despite conflicting results from cancer epidemiological studies, it is evident that single GR can contribute to the total load of environmental mutagens in a group of treated patients.

Inhibitory Efect of Uprocessed/Processed Aliums under in vitro/in vivo Conditions on Carcinogen Induced Mutagenesis Using Different Assays

Three experiments were carried out to assess the antimutagenic potential of garlic or onion This was tested in, in vitro/in vivo models where mutagenicity was induced either with benzo (a) pyrene (BP)/3-methyl-cholanthrene (3MC), using Ames test or the comet assay. Also the effects of cooking processes like boiling/frying on the antimutagenic potential of these alliums were tested by SOS inhibition assay using 4-nitroquinoline-N-oxide (4 NQO) as the mutagen. In the first experiment, onion feeding at 1 and 5% in the diet inhibited the formation and excretion of urinary mutagens in dose dependent manner as indicated by decreased frequency of revertants in strains TA 98 and TA100 in the presence of urine belonging to rats fed onion and exposed to BP or 3MC. In the second experiment using SOS induction assay, both processed or unprocessed garlic exhibited dose dependent inhibition of SOS induction. However with boiled/unboiled onion this was not statistically significant. Studies with DAS also showed a dose dependent inhibition of SOS induction. No significant differences were observed in inhibition of SOS responses with processing of onion/garlic. These results indicate that the antimutagenic principle in garlic is not destroyed on heat treatment during cooking processes. In the third experiment, BP treatment resulted in comet induction (as judged by the comet ratio¬diameter/length) significantly as compared to control, both in liver and kidney tissues (p<0.001). Allium vegetables fed groups showed values similar to control group. As was observed in the peripheral blood lymphocytes, a trend towards recovery from damage was noted both in liver and kidney tissue due to prior allium feeding. All these results show that alliums whether in the processed or unprocessed form can be used in diets to avert toxic effects of environmental carcinogens/genotoxicants and can be potent chemopreventive agents and cancer prevention is far more desirable alternative than treatment by surgery and drugs. The protection could be achieved even by very low intake level of allium in natural form through diet.

Biomarkers of Exposure, Effect, and Susceptibility in Workers Exposed to Nitrotoluenes

Nitrotoluenes, such as 2-nitrotoluene, 2,4-dinitrotoluene (24DNT), and 26DNT, are carcinogenic in animal experiments. Humans are exposed to such chemicals in the workplace and in the environment. It is therefore important to develop methods to biomonitor people exposed to nitrotoluenes to prevent the potential harmful effects. For the present study, workers exposed to high levels of these chemicals were investigated. The external dose (air levels), the internal dose (urine metabolites), the biologically effective dose [hemoglobin (Hb) adducts and urine mutagenicity], and biological effects (chromosomal aberrations and health effects) were determined. Individual susceptibility was assessed by determining genetic polymorphisms of enzymes assumed to function in nitrotoluene metabolism, namely glutathione S-transferases (GSTM1, GSTT1, GSTP1), N-acetyltransferases (NAT1, NAT2), and sulfotransferases (SULT1A1, SULT1A2). The levels of urinary metabolites did not correlate with the air levels. The urinary mutagenicity levels determined in a subset of workers correlated with the levels of a benzylalcohol metabolite of DNT. The Hb-adducts correlated with the urine metabolites but not with the air levels. The frequency of chromosomal aberrations (gaps included) was increased (P < 0.05) in the exposed workers in comparison with a group of factory controls and correlated with the level of 24DNT Hb-adducts in young subjects (<31 years). The GSTM1-null genotype was significantly more prevalent in the controls than in the exposed group, which probably reflected an elevated susceptibility of the GSTM1-null genotype to adverse health effects of DNT exposure, such as nausea (odds ratio, 8.8; 95% confidence interval, 2.4-32.2). A statistically significant effect was seen for SULT1A2 genotype on a 24DNT Hb-adduct; GSTP1 genotype on a 2,4,6-trinitrotoluene Hb-adduct; and SULT1A1, SULT1A2, NAT1, GSTT1, and GSTP1 genotypes on chromosomal aberrations in the exposed workers.

External Contamination of Cytotoxic Drug Vials

Journal of Pharmacy Practice and ResearchVolume 35, Issue 4 p. 264-265 EditorialFree Access External Contamination of Cytotoxic Drug Vials Peter J Gilbar BPharm, MPallC, FISOPP, FSHP, DipHospClinPharmPract Co-Chair, Peter J Gilbar BPharm, MPallC, FISOPP, FSHP, DipHospClinPharmPract Co-Chair [email protected] Committee of Specialty Practice in Oncology The Society of Hospital Pharmacists of Australia, Senior Pharmacist—Oncology/Palliative Care Toowoomba Health Services, Toowoomba, Qld, 4350 AustraliaSearch for more papers by this author Peter J Gilbar BPharm, MPallC, FISOPP, FSHP, DipHospClinPharmPract Co-Chair, Peter J Gilbar BPharm, MPallC, FISOPP, FSHP, DipHospClinPharmPract Co-Chair [email protected] Committee of Specialty Practice in Oncology The Society of Hospital Pharmacists of Australia, Senior Pharmacist—Oncology/Palliative Care Toowoomba Health Services, Toowoomba, Qld, 4350 AustraliaSearch for more papers by this author First published: 13 April 2015 https://doi.org/10.1002/j.2055-2335.2005.tb00359.xCitations: 10AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article. References 1Baker ES, Connor TH. Monitoring occupational exposure to cancer chemotherapy drugs. Am J Health Syst Pharm 1996; 15: 2713– 23. 2 The Society of Hospital Pharmacists of Australia. Committee of Specialty Practice in Oncology. SHPA standards of practice for the safe handling of cytotoxic drugs in pharmacy departments. J Pharm Pract Res 2005; 35: 44– 52. 3Falck K, Grohn P, Sorsa M, Vainio H, Helnonen E, Holsti LR. Mutagenicity in urine of nurses handling cytotoxic drugs. Lancet 1979; 1: 1250– 1. 4Connor TH, Anderson RW, Sessink PJM, Broadfield L, Power LA. Surface contamination with antineoplastic agents in six cancer treatment centres in Canada and the United States. Am J Health Syst Pharm 1999; 56: 1427– 32. 5Ros JJW, Simons KA, Verzijl JM, et al. Practical applications of a validated method of analysis for the detection of traces of cyclophosphamide on injection bottles at an oncological outpatients centre. Ziekenhuisfarmacie 1997; 13: 168– 71. 6Delporte JP, Chenoix P, Hubert P. Chemical contamination of the primary packaging of 5-fluorouracil RTU solutions commercially available on the Belgian market. Environ Health Perspect 1999; 5: 119– 21. 7Nygren O, Gustavsson B, Strom L, Friberg A. Cisplatin contamination observed on the outside of drug vials. Ann Occup Hyg 2002; 46: 555– 7. 8Mason HJ, Morton J, Garfitt SJ, Iqbal S, Jones K. Cytotoxic drug contamination on the outside of vials delivered to a hospital pharmacy. Ann Occup Hyg 2003; 47: 681– 5. 9Favier B, Gilles L, Ardiet C, Latour JF. External contamination of vials containing cytotoxic agents supplied by pharmaceutical manufacturers. J Oncol Pharm Pract 2003; 9: 15– 20. 10Connor TH, Sessink PJM, Harrison B, et al. Surface contamination of chemotherapy drug vials and evaluation of new vial-cleaning techniques: results of three studies. Am J Health Syst Pharm 2005; 62: 475– 84. 11Schultz H, Bigelow S, Dobish R, Chambers CR. Antineoplastic agent workplace contamination study: the Alberta Cancer Board Pharmacy perspective. J Oncol Pharm Pract 2005; 11: 101– 9. 12Power LA. Demand clean vials [editorial]. Am J Health Syst Pharm 2005; 62: 471. Citing Literature Volume35, Issue4December 2005Pages 264-265 ReferencesRelatedInformation

Negative association between serum dioxin level and oxidative DNA damage markers in municipal waste incinerator workers

To investigate the effect of dioxin on the formation of oxidative DNA damage and urinary mutagenicity, we measured the concentrations of serum dioxins and lymphocytic 8-hydroxydeoxyguanosine (8-OH-dG) in 57 male waste incinerator workers, urinary 8-OH-dG and urinary mutagenicity in 29 male waste incinerator workers. Information about the subjects was obtained from a questionnaire. Concentrations of polychlorinated dibenzo-p-dioxin (PCDD), polychlorinated dibenzofuran (PCDF), and coplanar-polychlorinated-biphenyl (Co-PCB) in serum samples from the workers were measured with a high-resolution gas chromatograph /high-resolution mass spectrometer. Lymphocytic and urinary 8-OH-dG levels were measured with a high-performance liquid chromatography-electrochemical detector system. The urinary mutagenicity was measured with umu assay. The lymphocytic 8-OH-dG level showed a negative association with the serum dioxin level (total value of TEQ-PCDD, PCDF, and Co-PCB). Urinary 8-OH-dG did not show correlation with serum dioxin level, but showed positive correlation with the smoking index. With respect to the subjects' serum dioxin level, dioxin did not increase the urinary 8-OH-dG level by oxidative DNA damage, but upregulation of the primary defenses with oxidative damage and/or DNA repair system activity might have occurred.

Influence of the genetic polymorphism in the 5′-noncoding region of the CYP1A2 gene on CYP1A2 phenotype and urinary mutagenicity in smokers

The functional significance of genetic polymorphisms on tobacco smoke-induced CYP1A2 activity was examined. The influence of three polymorphisms of the cytochrome P450 1A2 gene ( CYP1A2) (− 3860 G → A (allele *1C), − 2467 T → delT (allele *1D), − 163 C → A (allele *1F)), located in the 5′-noncoding promoter region of the gene, on CYP1A2 activity (measured as caffeine metabolic ratio, CMR), was studied in Caucasian current smokers ( n = 95). Tobacco smoke intake was calculated from the number of cigarettes/day. Also, studied was the influence of these CYP1A2 genotypes on smoking-associated urinary mutagenicity, detected in Salmonella typhimurium strain YG1024 with S9 mix, considering the urinary excretion of nicotine plus its metabolites as an internal indicator of tobacco smoke exposure. Smokers with at least one of the variant alleles CYP1A2 − 3860A and − 2467 delT showed a significantly increased CYP1A2 CMR (− 3860 G/A versus G/G, p < 0.05; − 2467 delT/delT versus T/delT and T/T, p < 0.01). Multiple regression analysis showed that the increase in CYP1A2 CMR (ln values) was again significantly related to the presence of CYP1A2 variants − 2467delT and also to variant − 163A ( p < 0.05), but moderately to − 3860A ( p = 0.084). No influence of the number of cigarettes smoked per day by each subject was found. Heavy smokers ( n = 48, with urinary nicotine plus its metabolites ≥0.69 mg/mmol creatinine) with variant allele − 2467delT or − 163A had significantly increased urinary mutagenicity ( p < 0.01 and <0.05). CYP1A2 genetic polymorphisms are shown to influence the CYP1A2 phenotype in smokers, − 2467 T → delT having the main effect . This information is of interest for future studies assessing the possible role of tobacco smoke-inducible CYP1A2 genotypes as individual susceptibility factors in exposure to carcinogens.

Short‐Term Exposure Evaluation of Adult Smokers Switching From Conventional to First‐Generation Electrically Heated Cigarettes During Controlled Smoking

This randomized, controlled study in 110 male and female adult smokers evaluated biomarkers of tobacco smoke exposure (carbon monoxide [CO], carboxyhemoglobin [CO-Hb], nicotine, urine mutagenicity) under controlled smoking conditions when adult smokers of 1 conventional cigarette brand (CC1) were switched to an electrically heated cigarette smoking system (EHCSS) or a low-tar conventional cigarette (CC2). Baseline exposure was determined while all subjects smoked CC1. Subjects then were stratified for gender and cigarette consumption and randomized to 1 of 5 groups-EHCSS1, EHCSS2, CC1, CC2, or no smoking-and monitored for 8 days. Compared to baseline, biomarkers of exposure on day 8 decreased 53% to 93% (P < .0001) for EHCSS groups and 18% to 39% (P < .02) for CC2. Environmental tobacco smoke arising from the smoking activities of the different study groups was measured in the air of a separate smoking room over 1-hour periods. Concentrations of respirable suspended particulates in both EHCSS groups were about 90% lower than in the CC1 and CC2 groups, similar to the 95% reduction in the no-smoking group. CO was undetectable in the EHCSS and no-smoking groups. Results from this short-term clinical study indicate that switching from a conventional cigarette to a first-generation EHCSS reduces the generation of environmental tobacco smoke and can reduce the exposure to the measured, potentially harmful constituents in tobacco smoke if smokers do not compensate by numbers of cigarettes. The study design was found to be suitable for the evaluation of the exposure of adult smokers to the measured smoke constituents and to allow the differentiation of different cigarette designs.

Black tea intake modulates the excretion of urinary mutagens in rats exposed to 6-aminochrysene: induction of cytochromes P450 by 6-aminochrysene in the rat

Rats were exposed to black tea (2.5% w/v) as their sole drinking liquid for either 1 day (short-term) or 1 month (long-term), while controls received water. After exposure, all animals received a single oral dose of 6-aminochrysene and urine was collected for 72 h. Urinary mutagenicity was determined in the Ames test using an activation system comprising hepatic cytosol from Aroclor 1254-induced rats and utilizing the Salmonella typhimurium O-acetylase overexpressing bacterial strain YG1024. Both tea treatments suppressed the urinary excretion of indirect acting mutagens; no direct acting mutagenic activity was detectable. Furthermore, both tea treatments induced hepatic CYP1A2 activity, as exemplified by the O-demethylation of methoxyresorufin, when compared with the corresponding controls; similarly, an increase in CYP1A2 apoprotein levels was observed. The O-depentylation of pentoxyresorufin was also induced by the long-term tea treatment only, but the effect was less pronounced. No significant changes were seen in glutathione S-transferase and glucuronosyl transferase activities. When rats were exposed to caffeine at a dose level corresponding to that in black tea, a marked decrease was observed in the urinary excretion of indirect acting mutagens following a single oral dose of 6-aminochrysene. It is concluded that even after short-term exposure, black tea enhances the metabolism of 6-aminochrysene and that this is probably related to the up-regulation of hepatic CYP1A2 by the caffeine present in black tea. Finally, 6-aminochrysene was a potent inducer of CYP1A1, as assessed by the O-deethylation of ethoxyresorufin and immunoblot analysis. The same treatment modestly increased glutathione S-transferase activity when assessed using 1-chloro-2,4-dinitrobenzene as the accepting substrate.

Effect of Black Tea Intake on the Excretion of Mutagens in the Urine of Volunteers Taking a Beef Meal

Abstract The objective of this study was to investigate in a crossover study conducted in human volunteers whether black tea intake modulates the metabolism of heterocyclic amines, consumed in the form of well-cooked beefburgers, as exemplified by the excretion of mutagens in the urine. Mutagens were extracted from urine with blue rayon, and mutagenic activity was determined in the Ames test, in the presence of an activation system derived from Aroclor 1254–induced rats, and employing the Salmonella typhimurium O-acetylase over-expressing YG1024 bacterial strain. Volunteers consumed three well-cooked beefburgers, whereas a concurrently cooked fourth burger was analyzed for mutagenic activity. Following intake of the burgers, an increase in urinary mutagenic activity was observed, and mutagenic activity was completely excreted within 24 hours. A good correlation was obtained between the intake and excretion of mutagenic activity. The volunteers consumed the same burger meal on two different occasions, once following intake of 10 cups of strong black tea, and the second following intake of a corresponding volume of water. Urine was collected by each volunteer for 24 hours after the meal, and compliance was ascertained utilizing the excretion of p-aminobenzoic acid. The mutagenic ratio, defined as the ratio of urinary mutagenicity over the intake of mutagenicity, was not altered by the black tea, being 0.142 and 0.135 during the water and tea intake, respectively. It is inferred that short-term intake of high levels of black tea, as part of an otherwise normal diet, does not modulate the human metabolism of heterocyclic amines.

Potent suppressive effect of green tea polyphenols on tobacco-induced mutagenicity

Antimutagenic activity of green tea (Camellia sinensis) was studied using Salmonella typhimurium strains (TA 102) (Ames test). Aqueous tobacco extract was found to be mutagenic to S. typhimurium TA 102 at concentration of 50 mg/plate. Green tea polyphenols was found to inhibit the mutagenicity of tobacco in a concentration-dependent manner. Concentrations needed for 50% inhibition of mutagen-induced revertant formation was found to be 5 mg/plate. Green tea polyphenols was also found to inhibit the urinary mutagenicity in rats induced by tobacco extract. Moreover green tea polyphenols were found to inhibit in vitro nitrosation reaction produced by reaction sodium nitrite and methyl urea and further inhibition of mutagenicity indicating that green tea has dual action to bring out a reduction in the mutagenic and carcinogenic potential of tobacco.

Urinary Mutagenicity, CYP1A2 and NAT2 Activity in Textile Industry Workers

The two major causes of bladder cancer have been recognised to be cigarette smoke and occupational exposure to arylamines. These compounds are present both in tobacco smoke and in the dyes used in textile production. Aromatic amines suffer oxidative metabolism via P450 cytochrome CYP1A2, and detoxification by the polymorphic NAT2. The aim of the present work was to assess the association between occupational-derived exposure to mutagens and CYP1A2 or NAT2 activity. This cross-sectional study included 117 textile workers exposed to dyes and 117 healthy controls. The urinary mutagenicity was determined in 24 h urine using TA98 Salmonella typhimurium strain with microsomal activation S9 (MIS9) or incubation with beta-glucuronidase (MIbeta). Urinary caffeine metabolite ratios: AFMU+1X+1U/17U, and AFMU/AFMU+1X+1U were calculated to assess CYP1A2 and NAT2 activities, respectively. The results show that workers present a strikingly higher urine mutagenicity than controls (p<0.0001), despite the implementation of the new restrictive norms forbidding the industrial use of the most carcinogenic arylamines. Neither NAT2 nor CYP1A2 activity had any effect on the markers of internal exposure to mutagens, since no significant differences were observed when the urinary mutagenicity of slow and fast acetylators (p>0.05) was compared, and the urinary mutagenicity was not significantly associated with the CYP1A2 activity marker (r=0.04 and r=-0.01 for MIS9 and MIbeta, respectively). This study clearly indicates the need for further protective policies to minimise exposure to the lowest feasible limit in order to avoid unnecessary risks.