Biomedical subjects

M Villarini

Publications and source records attributed to M Villarini.

At least 19 recordsLinked to original sources

PubMed2005

Screening of potential lactobacilli antigenotoxicity by microbial and mammalian cell-based tests.

Antigenotoxicity is considered an important property for probiotic lactobacilli. The ability of non probiotic lactobacilli from dairy products and starters to inhibit two reference genotoxins: 4-nitroquinoline-1-oxide and N-methyl-N'-nitro-N-nitrosoguanidine was evaluated. The study was carried out using short-term assays with different targets, such as procaryotic cells (SOS-Chromotest for genotoxicity in Escherichia coli and Ames test for mutagenicity in Salmonella typhimurium) and eucaryotic cells (Comet assay for genotoxicity in Caco-2 enterocytes). A high proportion of strains inhibiting 4-nitroquinoline-1-oxide activity was found in Lactobacillus casei, Lactobacillus acidophilus, Lactobacillus rhamnosus, Lactobacillus delbrueckii subsp. bulgaricus and Lactobacillus plantarum. Inhibition of N-methyl-N'-nitro-N-nitrosoguanidine activity occurred in only one L. acidophilus strain. All the strains with antigenotoxic properties also demonstrated antimutagenic activity and produced modifications in genotoxin spectroscopic profiles. Strain viability during and after genotoxin exposure was confirmed. Concordance of the results obtained with microbial and mammalian cell-based tests is underlined.

4-Nitroquinoline-1-oxide↗

PubMed2003

Primary DNA damage in chrome-plating workers.

In order to evaluate the primary DNA damage due to occupational exposure to chromium (VI), DNA strand-breaks and apoptosis in peripheral lymphocytes were measured in a group of 19 chrome-plating workers. DNA strand-breaks was assessed by alkaline (pH>13) single-cell microgel electrophoresis ('comet') assay, while apoptosis was measured by flow-cytometry after propidium iodide staining of the cells. Concentrations of chromium in urine, erythrocytes and lymphocytes were investigated as biological indicators of exposure. A group of 18 hospital workers (control group I) and another 20 university personnel (control group II) without exposure to chromium were also studied as controls. The results of the study show that chrome-plating workers have higher levels of chromium in urine, erythrocytes and lymphocytes than unexposed workers. Comet tail moment values, assumed as index of DNA damage, are increased in chromium-exposed workers and results are significantly correlated to chromium lymphocyte concentrations. No difference emerged in the percentage of apoptotic nuclei in exposed and unexposed workers. The study confirms that measurements of chromium in erythrocytes and lymphocytes may provide useful information about recent and past exposure to hexavalent chromium at the workplace. The increase in DNA strand-breaks measured by comet assay suggests this test is valid for the biological monitoring of workers exposed to genotoxic compounds such as chromium (VI).

Adult↗

PubMed2001

Monitoring airborne genotoxicants in the rubber industry using genotoxicity tests and chemical analyses.

This research was designed to examine the presence of mutagenic/carcinogenic compounds in airborne pollutants in the rubber industry using an integrated chemical/biological approach. Inhalable airborne particulate matter (PM-10: <10 microm) was collected in four rubber factories using a high-volume sampler equipped with a cascade impactor for particle fractionation. The organic extracts of two different fractions (0.5-10 microm and <0.5 microm) were examined for mutagenicity with the Ames test and for in vitro DNA-damaging activity in human leukocytes by single-cell microgel electrophoresis (Comet assay). The extracts were also studied by gas chromatography/mass spectrometry (GC/MS) for polycyclic aromatic hydrocarbon (PAH) content. Nitrosamines in ambient air were sampled on cartridges and analysed by GC with a thermal energy analyser (TEA) detector. Airborne volatile genotoxins were monitored in situ using a clastogenicity plant test (Tradescantia/micronuclei test). The results showed that airborne particulates were mainly very fine (<0.5 microm) and that trace amounts of genotoxic nitrosamines (N-nitrosodimethylamine: 0.10-0.98 microg/m(3); N-nitrosomorpholine: 0.77-2.40 microg/m(3)) and PAH (total PAH: 0.34-11.35 microg/m(3)) were present in air samples. Some extracts, particularly those obtained from the finest fractions, were mutagenic with the Ames test and genotoxic with the Comet assay. In situ monitoring of volatile mutagens using the Tradescantia/micronuclei test gave positive results in two working environments. The results showed the applicability of this integrated chemical-biological approach for detecting volatile and non-volatile genotoxins and for monitoring genotoxic hazards in the rubber industry.

Air Pollutants, Occupational↗

PubMed2001

Environmental assessment of a site contaminated by organic compounds.

This paper presents a study on environmental assessment of an abandoned industrial area located in central Italy. Main production was refractory materials and compounds for treatment of industrial wastewater. The present work deals with a methodology for development of a sound sampling design, chemical characterization of soil samples, definition of the degree of site contamination according to law limits and evaluation of the fate and transport of contaminants by EPA simulation model (VLEACH 2.2a). Results indicate that toxic compounds (polycyclic aromatic hydrocarbons and plasticizers) are uniformly distributed in the contaminated site and only in one sampling point their concentrations exceed law limits. Modeling results confirm that contaminants migration to groundwater can be excluded, addressing for a site remediation limited to the surface layer.

Environmental Monitoring↗

PubMed2000

Effect of three diaryl tellurides, and an organoselenium compound in trout erythrocytes exposed to oxidative stress in vitro.

Previous literature reports have demonstrated that nucleated trout erythrocytes in conditions of oxidative stress are subjected to DNA and membrane damage, and inactivation of glutathione peroxidase. The present study was undertaken to evaluate the ability of three diaryl tellurides and the organoselenium compound ebselen to protect trout (Salmo irideus) erythrocytes against oxidative stress, induced thermally and by a variation of pH. The antioxidant ability of these molecules was evaluated through chemiluminescence. Impairment of DNA was assessed using the comet assay, a rapid and sensitive single cell gel electrophoresis technique, used to detect primary DNA damage in individual cells. At low concentrations (<10 microM), all the compounds used presented a protective effect on DNA damage without altering the hemolysis rate. In higher concentrations, they accelerated the hemolysis rate and two of the diaryl tellurides were strongly genotoxic.

Animals↗

PubMed2000

In vitro genotoxicity of terbutryn evaluated by the alkaline single-cell microgel-electrophoresis "comet" assay.

Terbutryn, a s-triazine herbicide, is extensively used in agriculture as a selective pre- and postemergence control agent for most grasses and many annual broadleaf weeds in cereal and legume fields, and under fruit trees. Terbutryn was reported to degrade slowly, with half-lives of 240 and 180 days in pond and river sediment, respectively. The tendency of this herbicide to move from treated soils to water compartments through water runoff and leaching was demonstrated and residual amounts of terbutryn and its metabolites have been found in drinking water, and industrial food products, long after application. Although this herbicide may be regarded as a contaminant of our environment, only limited and inconsistent data exist concerning its genotoxic properties. In this study, the DNA-damaging ability of the herbicide was evaluated in the alkaline single-cell microgel-electrophoresis ("comet") assay by testing terbutryn in the presence of S9mix (rat liver homogenate containing microsomal enzymes plus cofactors) prepared with liver homogenate from both uninduced (basal) and aroclor 1254-induced rats. DNA damage was recorded in freshly isolated human peripheral blood leukocytes. A statistically significant increase in the extent of primary DNA damage, more pronounced in the absence of S9mix, took place only when terbutryn concentrations were high (100 and 150 microg/ml), in the presence of a concomitant mild cytotoxic effect.

Adult↗

PubMed1998

In vitro genotoxic effects of the insecticide deltamethrin in human peripheral blood leukocytes: DNA damage ('comet' assay) in relation to the induction of sister-chromatid exchanges and micronuclei.

Deltamethrin, a synthetic dibromo-pyrethroid insecticide, is extensively used in agriculture, forestry and in household products because of its high activity against a broad spectrum of insect pests (both adults and larvae), its low animal toxicity and its lack of persistence in the environment. Data on the genotoxicity and carcinogenicity of deltamethrin are rather controversial, depending on the genetic system or the assay used. The aim of this study was to further evaluate the potential genotoxic activity of deltamethrin. The in vitro genotoxicity of deltamethrin has been evaluated by assessing the ability of the insecticide to damage DNA (as evaluated using the single-cell microgel-electrophoresis or 'comet' assay) or induce sister-chromatid exchanges (SCE) and micronuclei (MN) in human peripheral blood leukocytes. All treatments were conducted with and without the presence of an external bioactivation source (+/- S9mix). The results indicate that deltamethrin, in the presence of metabolic activation (+ S9mix), is able to induce DNA damage (double- and single-strand breaks, alkali-labile sites and open excision repair sites) as revealed by the increasing tail moment values observed with increasing doses. The frequency of SCE and MN were not statistically increased in deltamethrin-treated cells as compared to controls, both with and without S9mix. However, lower deltamethrin doses were tested, as compared to 'comet' assay, because of cytotoxicity.

Adult↗

PubMed1998

Extent of DNA damage in density-separated trout erythrocytes assessed by the 'comet' assay.

The 'comet' assay is being increasingly employed for evaluating DNA damage in biological systems. Using this technique, we examined DNA damage in whole in density-separated trout erythrocytes. Results clearly show that all the three considered parameters (tail length, tail intensity and tail moment) increased with the density of the fractions, possibly reflecting different degrees of DNA damage. Probably, this behaviour is due to different periods of exposure of the density fractions to the hazard of active oxygen radicals; older cells have been exposed to oxidative stress for a longer time.

Animals↗

PubMed1998

Detection of DNA damage in stressed trout nucleated erythrocytes using the comet assay: protection by nitroxide radicals.

Because previous literature reports have demonstrated that nucleated trout erythrocytes in conditions of oxidative stress are subjected to both membrane damage and a decrease in the enzymatic defense systems (glutathione peroxidase), which in turn lead to hemolysis, the present study was undertaken to determine whether DNA may be affected too, prior to the hemolytic event. Impairment of DNA in stressed trout erythrocytes was assessed using the comet assay--a rapid and sensitive, single-cell gel electrophoresis technique used to detect primary DNA damage in individual cells. In addition, indolinic and quinolinic nitroxide radicals were included in the study to determine their efficacy as antioxidants against free-radical-induced DNA damage. The parameters, tail length, tail intensity, and tail moment, used as an index of DNA damage, have shown that trout erythrocytes exposed to oxidative stress experience DNA damage prior to hemolysis and that the nitroxides significantly prevent this damage. This result provides further information about the potential use of these compounds as antioxidants in biological systems.

Animals↗

PubMed1998

Mutagenicity and clastogenicity of gas stove emissions in bacterial and plant tests.

The aim of this research was to study the gaseous and particulate emissions of genotoxic substances during cooking with two types of methane stoves (a new one and an old one). The particulates were sampled both with a cascade impactor air sampler and an impinger with ice trap and analyzed by two bacterial mutagenicity tests (Ames and Kado tests) and by HPLC for polycyclic aromatic hydrocarbons (PAH). Gaseous emissions were studied in situ using the Ames test, a clastogenicity plant test (Tradescantia-micronucleus test), and in an automated system for chemical analyses. Clear indirect mutagenicity was found only with the Kado test (TA98-S9) in extracts of particulates emitted from the old methane stove and collected with the impinger. Similar mutagenicity (TA98+S9) was also found for the finest fraction of particulates (<0.5 um) collected from both stoves. Gaseous emissions of both stoves caused clastogenicity in the in situ experiments with the Tradescantia-micronucleus test. The physico-chemical analyses of the emissions showed also the presence of very fine particulates and trace amounts of PAH. The exposure of these genotoxins could be particularly important for occupationally exposed individuals in homes and businesses and for susceptible subjects living indoors for long periods (infants, children, the sick, and the elderly).

Air Pollutants↗

PubMed1997

In vivo studies on genotoxicity of pure and commercial linuron.

The ureic herbicide linuron [3-(3, 4-dichlorophenyl)-1-methoxy-1-methylurea] (CAS 330-55-2) was investigated for genotoxicity in a series of in vivo experiments. Since human exposure to herbicides is not only to the active principles, but also to all the chemicals present in the commercial formulation, we tested both pure and commercial linuron. Groups of rats were treated with gavage containing different doses of the herbicide (pure compound or commercial formulation) for 14 days. The doses were 150, 300 and 450 mg/kg b.wt. for the pure compound and 315.8, 631.6 and 947.4 mg/kg b.wt. for the commercial formulation (47.5% of linuron). Faeces and urine were collected at regular intervals. Urine specimens were analysed for their mutagenic metabolites, thioethers and D-glucaric acid content. Faeces extracts were tested for mutagenicity. Linuron's ability to cause DNA damage and cytogenetic effects was also investigated after treating groups of rats once with different doses of pure or commercial linuron. DNA single-strand breaks were assessed in rat liver using the alkaline elution technique and the single-cell microgel electrophoresis assay (SCGE: 'comet' assay), and in rat testes cells with the SCGE assay. Micronuclei induction was analysed in rat bone marrow erythrocytes. Results obtained were mainly negative when the excretion of mutagenic metabolites in urine and faeces of animals treated with the pure compound or with the linuron-based commercial formulation were monitored, whereas an increase in the urinary excretion of thioethers and D-glucaric acid was observed in rats treated with the commercial formulation. No increase in the frequency of micronucleated polychromatic erythrocytes was observed in the treated animals. However, linuron affected the viability of hepatocytes isolated from animals treated with higher doses. This cytotoxicity was accompanied by the induction of DNA single-strand breaks in the liver, as seen by the alkaline elution assay. The potential of pure linuron to induce in vivo DNA damage was confirmed with the microgel-electrophoresis technique ('comet' assay). Cytotoxicity was also seen in rat testes cells. However, no indication of DNA damage was visible.

Administration, Oral↗

PubMed1997

Applicability of aspecific noninvasive methods for biomonitoring of occupational exposure to deltamethrin: preliminary study using an animal model.

Deltamethrin (CAS registry No. 52918-63-5), a synthetic dibromo-pyrethroid insecticide is highly effective against a broad spectrum of insects, and is widely used on crops and in public health programs. Data on the genotoxicity and carcinogenicity of deltamethrin are rather controversial, depending on the genetic system or the assay used. The aim of the present study was to analyze previously demonstrated metabolic changes using aspecific noninvasive methods in rats which are potentially applicable for monitoring occupational exposure. Since human exposure to pesticides occurs not only to active principles but to all chemicals present in a commercial formulation, we tested both the pure compound and a deltamethrin-based commercial formulation. Groups of rats were treated, i.p., consecutively for 7 days. The daily doses tested were 5 and 10 mg/kg body weight for pure deltamethrin, corresponding to volumes of 178.57 and 377.14 microliter/kg body weight for the commercial formulation (containing 2.8% deltamethrin). Urine was analyzed for mutagenic metabolites, thioethers, and D-glucaric acid content. Faeces extracts were tested for mutagenicity. Results show that DGA urinary excretion values did not mirror the phase I enzyme induction capability of the insecticide. Results obtained for urinary thioethers do not agree completely with those obtained on the influence of deltamethrin on glutathione S-transferase activity in rat liver. In fact, after administration of the deltamethrin commercial formulation, highest thioether excretion values were obtained during the treatment time for treated animals, as compared to controls. The mean values (+/-SEM) of thioether excretion were 0. 033 +/- 0.002 micromole -SH/24 h for control animals, 0.122 +/- 0. 004 and 0.185 +/- 0.025 for the two treatment groups. Thence, thioether determination in urine samples seems to be a suitable aspecific noninvasive method for assessing exposure to deltamethrin-based formulations, particularly those containing xylene and mesitylene as solvents, as in the tested formulation. Negative or toxic results obtained in the urinary and faecal mutagenicity test seem to exclude the formation and excretion of mutagenic metabolites following treatment with deltamethrin.

Animals↗

PubMed1996

Urine mutagenicity and biochemical effects of the drinking water mutagen, 3-chloro-4-(dichloromethyl)-5-hydroxy-2[5H]-furanone (MX), following repeated oral administration to mice and rats.

Mutagenicity analysis of urine from rats treated by oral gavage with MX at a dose of 64 mg/kg for 14 days revealed that only 0.3% of the administered compound was excreted in a genotoxically active form. At lower doses, mutagenicity was not detectable. No evidence of micronucleus induction in peripheral blood erythrocytes was observed in mice treated similarly. These findings indicate that MX is extensively detoxified in vivo and is unlikely to cause genetic damage in systemic tissues except at relatively high doses where detoxification pathways become saturated. In a separate experiment, significant depressions were observed in D-glucaric acid and thioether excretion and in levels of several liver enzymes involved in xenobiotic metabolism. The mechanism for these metabolic alterations and their relevance to the in vivo metabolism of the compound require further investigation.

Administration, Oral↗

PubMed1996

Biological monitoring of genotoxic hazard in workers of the rubber industry.

Biological monitoring of genotoxic hazard in the rubber industry was performed in 19 male workers and 20 age-matched controls in a local health unit in northern Italy. Peripheral blood lymphocytes were analyzed for the presence of DNA damage (single-cell microgel-electrophoresis, or comet assay) and for cytogenetic parameters (sister chromatid exchanges and micronuclei frequency, and proliferative rate index). The following bioassays were performed in urine samples: a) mutagenicity test and concentration of thioethers as markers of exposure, and b) excretion of D-glucaric acid and 6-beta-hydroxycortisol (related to 17-hydroxycorticosteroid excretion) as indicators of the inductive status of the microsomal enzyme system (phase-I). The exposed subjects showed statistically higher mean values of 17-hydroxycorticosteroids and micronuclei and lower values of 6-beta-hydroxycortisol than controls, when taking cigarette smoking into account. The comet assay showed higher values for migration distance in exposed subjects than controls, although the differences were not significant at a p-value of 0.05. These findings suggest that industrial exposure in the rubber processing industry may cause genetic damage and may modify the activity level of some enzymes; these results should be considered with caution due to the small number of subjects enrolled.

Adult↗

PubMed1995

Studies on hepatic xenobiotic-metabolizing enzymes in rats treated with insecticide deltamethrin.

The effects of the synthetic dibromo-pyrethroid insecticide deltamethrin on some hepatic phase I and II enzyme activities were studied in rat liver. The animals were treated with daily doses of 5 and 10 mg/kg of both pure insecticide or its commercial formulation (Decis), administered i.p. in corn oil for 7 days. The following enzyme activities were studied: NADPH-cytochrome-P450 reductase, aryl-hydrocarbon hydroxylase, aminopyrine N-demethylase, glutamyl cysteine synthetase, glutathione S-transferase, glutathione peroxidase, peroxisomal acyl-CoA oxidase, catalase, and urate oxidase. Both deltamethrin and its commercial formulation were effective in modifying the activities of several of these hepatic xenobiotic-metabolizing enzymes. However, some differences in enzyme modifications were found between treatment with pure or commercial deltamethrin, the latter being more active. This effect could be ascribed to additives, solvents, and chemical intermediates present in the Decis formulation. These results suggest that exposure to this deltamethrin commercial formulation could be more dangerous than exposure to deltamethrin alone, both in terms of its hepatotoxicity and/or alterations in the hepatic biotransformation of other occupational/environmental xenobiotics.

Aminopyrine N-Demethylase↗

PubMed1994

In vivo studies on enzymatic induction activity of Linuron.

The effect of the ureic herbicide Linuron [3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea] on the levels of some hepatic xenobiotic metabolizing enzymes was studied in rats. The cytochrome P450-dependent monooxigenase activities of aryl hydrocarbon hydroxylase (AHH) and of aminopyrine N-demethylase (APD) were measured in rat livers after a 14-d treatment by gavage with Linuron. AHH was employed as a marker of the catalytic activity of P450IA1 and APD as a marker of the catalytic activity of P450IIB1/2. Furthermore, the enzymatic activities of the cytosolic via glutathione detoxifying enzymes glutathione peroxidase and glutathione S-transferase were assessed. Three doses of Linuron (both as pure compound and as commercial preparation) were tested. The doses tested were 150, 300, and 450 mg/kg body weight for the pure compound and 315.8, 631.6, and 947.4 mg/kg for the commercial preparation. Differences were found in the relative liver weight only in rats treated with the commercial formulation. The aryl hydrocarbon hydroxylase activity was increased with all the tested doses of pure and commercial Linuron. A reduction in the aminopyrine N-demethylase activity was noted for the highest dose of pure Linuron, whereas an increment in this activity was observed for all the doses of the commercial preparation tested. The activity of glutathione peroxidase was not affected by treatment with the pure product; however, an increment in activity was observed at all the tested doses of the commercial preparation. The glutathione S-transferase activity was reduced in both cases.

Aminopyrine N-Demethylase↗

PubMedDate not supplied

Micronucleus induction in cells co-exposed in vitro to 50 Hz magnetic field and benzene, 1,4-benzenediol (hydroquinone) or 1,2,4-benzenetriol.

The generation, transmission (e.g. power lines, transformers, service wires, and electrical panels), and use (e.g. home appliances, such as electric blankets, shavers, and televisions) of electrical energy is associated with the production of weak electric and magnetic fields (EMF) which oscillate 50 (Europe) or 60 (USA) times per second (power-line frequency), falling in the extremely-low frequency (ELF) region of the electromagnetic spectrum. Epidemiological reports suggest a possible association between exposure to ELF-EMF and an increased risk of cancer (e.g. childhood acute leukaemia). Benzene is an established human leukomogen. This xenobiotic, which is unlikely to be the ultimate carcinogen, is metabolized in the liver to its primary metabolite phenol, which is hydroxylated to hydroquinone (1,4-benzenediol) and 1,2,4-benzenetriol. In this in vitro approach, to test the genotoxic and / or co-genotoxic potency of ELF-EMF, the cytokinesis block micronucleus (MN) method with Jurkat cells has been used. A 50 Hz magnetic field (MF) of 5 mT field strength was applied for different length of time (from 1 to 24 h), either alone or with benzene, 1,4-benzenediol, or 1,2,4-benzenetriol. Our preliminary results show that, after 24 h exposure, the frequency of micronucleated cells in MF-exposed cultures is 1.9 fold higher than in sham-exposed (control) cultures. Benzene exposure does not show any cytogenetic activity, whereas 1,4-benzenediol or 1,2,4-benzenetriol alone significantly affect the number of MN in Jurkat cells, as compared to untreated cultures. Moreover, co-exposure to ELF-MF does not seem to affect the frequency of micronuclei induced by benzene, 1,4-benzenediol, or 1,2,4-benzenetriol.

Benzene↗

PubMedDate not supplied

Assay of linuron and a pesticide mixture commonly found in the Italian diet, for promoting activity in rat liver carcinogenesis.

The herbicide linuron and a mixture of 15 pesticides commonly found in the Italian diet have been assayed for promoting activity in rat liver carcinogenesis. Composition of the pesticide mixture was: benomyl (19.55%); dithiocarbamates (20.67%); thiabendazole (14.94%); diphenylamine (14.25%); chlorthalonil (13.13%); procymidone (7.96%); fenarimol (1.95%); chlorpropham (0.70%); vinchlozolin (0.28%); methidathion (2.37%); chlorpyriphos-ethyl (2.09%); parathionmethyl (1.00%); chlorfenvinphos (0.27%); parathion (0.70%); pyrimiphos-ethyl (0.14%). To determine promoting activity we evaluated induction of preneoplastic foci in diethylnitrosamine-initiated hepatocytes, by positive gammaglutamyl-transpeptidase (GGTase) staining in liver slides, and peroxisome proliferation by peroxisomal-dependent catalase and palmitoyl-CoA-oxidase dosage. For the assay, groups of male Sprague-Dawley rats were initiated with 100 mg/kg diethylnitrosamine intraperitoneally and, one week later, given 150 mg/kg/day linuron or 10 mg/kg/day pesticide mixture, administered by gavage three days a week. All rats were 2/3 hepatectomized at the beginning of the 3rd week. All treatments were terminated at the end of the 8th week, and the rats were sacrificed one week later. No significant increases in number and area (mm2) per slide unit area (cm2) of GGTase-positive foci could be observed in linuron-treated rats (5.84 +/- 1.62/cm2; 0.139 +/- 0.041 mm2/cm2) with respect to controls only initiated with diethylnitrosamine (4.47 +/- 1.30/cm2; 0.182 +/- 0.078 mm2/cm2). After treatment with the pesticide mixture, the number of preneoplastic foci was instead significantly increased (6.91 +/- 2.05/cm2) although the area was not (0.188 +/- 0.128 mm2/cm2). Moreover, no increases in the peroxisome proliferation enzymatic markers were observed in either treated groups. The results imply a possible carcinogenic risk for the population stemming from promoting activities of pesticide mixtures.

Animals↗