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p-Synephrine (SN) is an alkaloid added to thermogenic formulations for weight loss that is predominantly absorbed in the human gastrointestinal tract (GI). As the adverse effects of SN on GI cells ...

Occupational exposure to lead (Pb) continues to be a serious public health concern and may pose an elevated risk of genetic oxidative damage. In Brazil, car battery manufacturing and recycling factories represent a great source of Pb contamination, and there are no guidelines on how to properly protect workers from exposure or to dispose the process wastes. Previous studies have shown that Pb body burden is associated with genetic polymorphisms, which consequently may influence the toxicity of the metal. The aim of this study was to assess the impact of Pb exposure on DNA oxidative damage, as well as the modulation of hemochromatosis (HFE) polymorphisms on Pb body burden, and the toxicity of Pb, through the analysis of 8-hydroxy-2′-deoxyguanosine (8-OHdG), in subjects occupationally exposed to the metal. Male Pb-exposed workers (n = 236) from car battery manufacturing and recycling factories in Brazil participated in the study. Blood and plasma lead levels (BLL and PLL, respectively) were determined by ICP-MS and urinary 8-OHdG levels were measured by LC-MS/MS, and genotyping of HFE SNPs (rs1799945, C → G; and 1800562, G → A) was performed by TaqMan assays. Our data showed that carriers of at least one variant allele for HFE rs1799945 (CG + GG) tended to have higher PLL than those with the non-variant genotype (β = 0.34; p = 0.043); further, PLL was significantly correlated with the levels of urinary 8-OHdG (β = 0.19; p = 0.0060), while workers that carry the variant genotype for HFE rs1800562 (A-allele) showed a prominent increase in 8-OHdG, as a function of PLL (β = 0.78; p = 0.046). Taken together, our data suggest that HFE polymorphisms may modulate the Pb body burden and, consequently, the oxidative DNA damage induced by the metal.

Thermogenic supplements containing synephrine (SN) are widely used to weight loss. SN is a proto-alkaloid naturally found in the bark of immature fruits of Citrus aurantium (bitter orange) that has been added to thermogenic supplements due to its chemical and pharmacological similarity with adrenergic amines, such as ephedrine and amphetamines. Although orally ingested SN is mainly metabolized in the liver, it remains unclear whether it affects the redox status and genetic material of human hepatic cells. The present study aims to examine whether SN affects cell viability, cell cycle, redox balance, genomic stability, and expression of the DNA damage response (DDR)-related genes ATM, ATR, CHEK1, CHECK2, TP53, and SIRT1 in HepG2 cells – used as in vitro hepatocyte model. SN induced overproduction of intracellular reactive oxygen species (ROS) after 6 h of treatment with the three concentrations tested (2, 20 and 200 μM). After 24 h of treatment, SN at 200 μM induced intracellular ROS overproduction and exerted cytostatic effects, while SN at 20 and 200 μM increased the levels of GPx and GSH. SN was not cytotoxic (2–5000 μM), genotoxic, and mutagenic and did not alter the expression of DDR-related genes (2–200 μM), indicating that the fast/specific SN metabolization and upregulation of antioxidant defense components to detoxify intracellular ROS were sufficient to prevent intracellular damage in HepG2 cells. In conclusion, SN showed no cytotoxic, genotoxic, and mutagenic potential at relevant concentrations for thermogenic users in human hepatic cells in vitro, although, it plays pro-oxidative action, and cytostatic effects. Taken together, our results suggest that other investigations about the hazard absence of this thermogenic compound should be performed.

2018/24643-1 (São Paulo Research Foundation, FAPESP, Brazil), by the National Council for Scientific and Technological Development (Brazil) and by grant UID-BIM-00009-2020 (Foundation for Science and Technology, FCT, Portugal). Experimental and epidemiologic studies have shown that lead (Pb) is able to induce epigenetic modifications, such as changes in DNA methylation profiles, in chromatin remodeling, as well as the expression of non-coding RNAs (ncRNAs). However, very little is known about the interactions between microRNAs (miRNAs) expression and DNA methylation status in individuals exposed to the metal. The aim of the present study was to investigate the impact of hsa-miR-148a expression on DNA methylation status, in 85 workers exposed to Pb. Blood and plasma lead levels (BLL and PLL, respectively) were determined by ICP-MS; expression of the miRNA-148a was quantified by RT-qPCR (TaqMan assay) and assessment of the global DNA methylation profile (by measurement of 5-methylcytosine; % 5-mC) was performed by ELISA. An inverse association was seen between miR-148a and % 5-mC DNA, as a function of BLL and PLL (β = −3.7; p = 0.071 and β = −4.1; p = 0.049, respectively) adjusted for age, BMI, smoking, and alcohol consumption. Taken together, our study provides further evidence concerning the interactions between DNA methylation profile and miR-148a, in individuals exposed to Pb. publishersversion published

It is well known that one of the most outstanding adverse effects related to lead (Pb) exposure is oxidative stress; moreover, recent findings suggest that disturbances of the redox status of cells are associated with epigenetic responses, and metabolism of glutathione (GSH) plays an important role in this process. This study aimed to assess Pb exposure on % methylation of GSH-related genes' promoter regions (%CH3-CpG) and their influence on biomarkers of oxidative stress, in workers exposed to the metal. One hundred nine male workers participated in the study; ICP-MS determined blood lead levels (BLL); biochemical parameters related to redox status, named GSH, glutathione peroxidase (GPX) and glutathione-S-transferase (GST) were quantified by UV/Vis spectrophotometry. Determination of %CH3-CpG of genes GCLC, GPX1, GSR, and GSTP1 were done by pyrosequencing. Inverse associations were seen between BLL and %CH3-CpG-GCLC, and %CH3-CpG-GSTP1. Moreover, metal exposure did not impact GSH, GPX, and GST; however, negative associations were observed between %CH3-CpG-GPX1 and %CH3-CpG-GSTP1, and the activities of GPX and GST, respectively. Taken together, our results give further evidence about adaptive epigenetic response to avoid oxidative damage induced by Pb exposure, allowing a better understanding of the molecular mechanisms related to the metal toxicity.

Made available in DSpace on 2020-12-10T20:11:02Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-09-01 Copaifera langsdorffiiL. is one of the most known medicinal species in Brazil. Its leaves are rich in phenolic compounds with potential biological activities as an antioxidant and chelating agent. This paper reports the isolation of four compounds from the hydroalcoholic extract of the leaves ofC. langsdorffiiand the investigation of their possible cytoprotective effects against heavy metal poisoning. Quercitrin (1), afzelin (2), 3,5-di-O-(3-O-methyl galloyl) quinic acid (3) and 4,5-di-O-(3-O-methyl galloyl) quinic acid (4), were associated with toxic doses of methylmercury and lead and evaluated by Alamar blue cell viability assays in HepG2 and PC12. The compounds displayed significant cytoprotective effect for the HepG2 cell line against both metals. Compounds 1-4 did not protect PC12 cells against methylmercury induced-cytotoxicity, but at lower concentrations, they protected against lead induced-cytotoxicity. The evaluated compounds showed a promising cytoprotection effect against exposure to heavy metals and should be further investigated as protective agents. Univ Sao Paulo, Dept Pharmaceut Sci, Ribeirao Preto, Brazil Sao Paulo State Univ, Dept Biol Sci, Araraquara, SP, Brazil Univ Sao Paulo, Dept Clin Toxicol & Bromatol Anal, Ribeirao Preto, Brazil Univ Franca, Nucleus Res Sci & Technol, Franca, SP, Brazil Sao Paulo State Univ, Dept Biol Sci, Araraquara, SP, Brazil

Individual susceptibility to the toxic effects induced by exposure to lead (Pb) may be affected by several variables, such as environmental factors, as well as intrinsic variations among the individuals, which are hypothetically associated to genetic differences in enzymes metabolizing the metal. Aim of the present study was to evaluate the effects of polymorphisms of glutathione (GSH)-genes related to the antioxidant status and Pb metabolism (GCLC, rs17883901 and GCLM, rs41303970) on Pb levels in blood (B-Pb) and plasma (P-Pb), as well as Pb-related effects on activity of glutathione-peroxidase (GPX) and on GSH concentrations. A cross-sectional study with 236 adults (men, >18 years old) was carried out with workers from automotive battery factories, Brazil. B-Pb and P-Pb were determined by ICP-MS; blood GPX and GSH were determined by spectrophotometry and qPCR TaqMan assays were used for genotyping. A questionnaire was applied in order to collect socio-demographic, lifestyle and time of exposure. The mean B-Pb level was 211 ± 118 μg/L and P-Pb was 6.05 ± 7.13 μg/L. GCLM are associated with changes of B-Pb and P-Pb; individuals who carry at least one polymorphic allele for GCLM gene had lower metal levels in the blood and plasma (β = −1.5; p = 0.0080; β = −0.12 and p = 0.050). In addition, individuals carrying at least one polymorphic allele for the GCLC gene had higher concentrations of GSH than the non-polymorphic ones, as a function of B-Pb (β = 0.072; p = 0.029). Significant associations were also observed with GCLC polymorphism on GSH concentrations (as a function of P-Pb), that is, polymorphic individuals tended to have higher concentrations of GSH than non-polymorphic ones (β = 0.072; p = 0.030), while those individuals who are polymorphic for GCLM had higher activities of GPX, compared to the non-variant genotype (β = 0.19; p = 0.028). Taken together, our data indicate that polymorphisms related to Pb toxicokinetics modify the metal body burden and Pb-related antioxidant effects.

A fast, high-throughput and accurate method was developed for determination of Al, As, Ba, Cd, Co, Cr, Cs, Cu, Fe, Mn, Ni, Pb, Se, U, Zn, Sb, Sn, I and Hg in urine and serum by inductively coupled ...

Anthracosilicosis (AS), a prevalent form of pneumoconiosis among coal miners, results from the accumulation of carbon and silica in the lungs from inhaled coal dust. This study investigated genotoxic effects and certain cytokine genes polymorphic variants in Russian coal miners with АS. Peripheral leukocytes were sampled from 129 patients with AS confirmed by X-ray and tissue biopsy and from 164 asymptomatic coal miners. Four single-nucleotide polymorphisms were genotyped in the extracted DNA samples: IL1β T-511C (rs16944), IL6 C-174G (rs1800795), IL12b A1188C (rs3212227) and VEGFA C634G (rs2010963). Genotoxic effects were assessed by the analysis of chromosome aberrations in cultured peripheral lymphocytes. The mean frequency of chromatid-type aberrations and chromosome-type aberrations, namely, chromatid-type breaks and dicentric chromosomes, was found to be higher in AS patients [3.70 (95% confidence interval {CI}, 3.29-4.10) and 0.28 (95% CI, 0.17-0.38)] compared to the control group [2.41 (95% CI, 2.00-2.82) and 0.09 (95% CI, 0.03-0.15)], respectively. IL1β gene T/T genotype (rs16944) was associated with AS [17.83% in AS patients against 4.35% in healthy donors, odds ratio = 4.77 (1.88-12.15), P < 0.01]. A significant increase in the level of certain chromosome interchanges among AS donors is of interest because such effects are typical for radiation damage and caused by acute oxidative stress. IL1β T allele probably may be considered as an AS susceptibility factor among coal miners.

Lead (Pb) is a toxic metal, frequently associated with occupational exposure, due to its widespread use in industry and several studies have shown high Pb levels in workers occupationally exposed to the metal. The aim of this study was to evaluate the influence of milk and dairy products (MDP) on Pb levels in blood (B-Pb), plasma (P-Pb), and urine (U-Pb), in workers from automotive battery industries in Brazil. The study included 237 male workers; information concerning diet and lifestyle were gathered through a questionnaire, and B-Pb, P-Pb, and U-Pb were determined by ICP-MS. Mean B-Pb, P-Pb, and U-Pb were 21 ± 12, 0.62 ± 0.73 μg/dL, and 39 ± 47 μg/g creatinine, respectively. Forty three percent of participants declared consuming ≤3 portions/week of MDP (classified as low-MDP intake), while 57% of individuals had >3portions/week of MDP (high-MDP intake). B-Pb and P-Pb were correlated with working time (r s = 0.21; r s = 0.20; p

Millions of humans are exposed occupationally and environmentally to lead, mercury and cadmium compounds. Mercury compounds are less abundant but some of them belong to the most toxic chemicals which are known. We evaluated the literature to find out if these metals act in humans as genotoxic carcinogens and if their health effects can be predicted by use of micronucleus (MN) assays with lymphocytes and/or with other genotoxicity tests. Numerous studies showed that lead and mercury induce cancer in humans and also in animals, in vitro experiments with cultured cells indicate that they cause DNA damage via different molecular mechanisms including release of reactive oxygen species and interactions with DNA repair processes. Also in most human studies, positive results were obtained in MN tests with lymphocytes (all 15 occupational studies with lead yielded positive results, with mercury 6 out of 7 investigations were positive). For cadmium, there is clear evidence that it causes cancer in humans; however, induction of chromosomal damage was only seen in high dose experiments with mammalian cells while results of animal and human studies yielded conflicting results (only in 2 of 5MN trials with humans positive findings were reported). Possibly, non-genotoxic mechanisms such as inhibition of apoptosis and interaction with signaling pathways account for the carcinogenic properties of cadmium species. The findings of MN studies with lead and mercury are in excellent agreement with results which were obtained with other endpoints (e.g. chromosomal aberrations and comet formations) and it is evident that this approach can be used for occupational and environmental monitoring of exposed individuals. Important future tasks will be the realization of larger studies with a uniform standardized protocol, the additional evaluation of anomalies other than MN (nuclear buds and bridges) and the combination of such trials with investigations which allow to define the molecular mechanisms relevant for exposed humans.

Immunosuppressive therapy can prevent rejection after organ transplantation. However, increased cancer risk is a serious complication among patients undergoing such therapy. We have evaluated whether prolonged use of immunosuppressive drugs is genotoxic. DNA instability was assessed, using the comet and micronucleus assays, in blood lymphocytes of 76 kidney transplant patients. DNA damage detected by the comet assay increased with time after transplantation. The estimated glomerular filtration rate of the patients did not influence the incidence of DNA damage. No association between micronucleated mononucleated cells and time elapsed after transplantation was observed. Our results suggest that prolonged use of immunosuppressive drugs in kidney transplant patients can induce genetic instability.

A simple and rapid procedure for simultaneous determination of 21 potential endocrine-disrupting chemicals (EDs) in urine samples by liquid chromatography–tandem mass spectrometry (LC–MS/MS) was developed. The novelty of the present procedure is based on the use of low-density solvent air-assisted liquid-liquid microextraction (LDS–AALLME) as a sample preparation step. The target analytes were 7 bisphenols, 7 parabens, 5 benzophenones, and two antimicrobials. The parameters (type and volume of solvent, extraction time (cycles), sample pH, ionic strength, and agitation) that influence the extraction efficiency in the LDS–AALLME were investigated and optimized. Under the optimized conditions, the matrix-matched calibration curves of all analytes presented correlation coefficients higher than 0.99 (range level of 1–20 ng mL−1). Very low LODs and LOQs ranging in 0.0003–0.15 ng mL−1 and 0.001–0.2 ng mL−1, respectively, were obtained. Recoveries from spiked samples at two concentrations (2.50 ng mL−1 and 15 ng mL−1) ranged from 91% to 120% while the precision (%, RSD) was lower than 15% for all studied compounds. The proposed combination of LDS–AALLME with LC–MS/MS is an environmentally friendly, sensitive and simple analytical alternative for the determination of EDs in urine samples without the use of any special apparatus for sample preparation, which is particularly suitable for human biomonitoring studies where many samples should be processed in less time. Finally, the proposed procedure was successfully applied to the determination of the analytes in 20 urine samples from Brazilians adults.

Chamomile is a medicinal plant, which presents several biological effects, especially the anti-inflammatory effect. One of the compounds related to this effect is apigenin, a flavonoid that is mostly found in its glycosylated form, apigenin-7-glucoside (APG), in natural sources. However, the affectivity and safety of this glycoside have not been well explored for topical application. In this context, the aim of this work was to develop and validate a reversed-phase high-performance liquid chromatography (RP-HPLC-DAD) method to quantify APG in chamomile preparations. Additionally, the safety and the anti-inflammatory potential of this flavonoid were verified. The RP-HPLC-DAD method was developed and validated with linearity at 24.0–36.0 μg/mL range (r=0.9994). Intra- and interday precision (RSD) were 0.27–2.66% and accuracy was 98.27–101.21%. The validated method was applied in the analysis of chamomile flower heads, glycolic extract, and Kamillen cream, supporting the method application in the quality control of chamomile preparations. Furthermore, the APG safety was assessed by MTT cytotoxicity assay and mutagenic protocols and the anti-inflammatory activity was confirmed by a diminished TNF-αproduction showed by mice macrophages treated with APG following LPS treatment.

Previous studies showed that lead (Pb) exposure may modulate gene expression by changes in the epigenetic status. However, little is known about the impact of Pb exposure and alterations on DNA methylation patterns in humans exposed to this metal. The aim of this study was to assess the consequences of exposure to Pb on DNA global methylation, in order to gain a better understanding of the interactions between Pb exposure and epigenetic effects. The study included 100 male workers employed in automotive battery factories from Paraná State, Brazil. Concentrations of Pb in blood (B-Pb) and plasma (P-Pb) were determined by ICP-MS, the percentage (%) of global DNA methylation was determined by quantification of 5-methylcytosine using indirect ELISA, and sociodemographic data collected by questionnaire by trained interviewers. The mean age was 37 ± 10 (18-67 years); 18% of participants were smokers, while 32% reported consumption of alcoholic beverages. The B-Pb and P-Pb levels were 20 ± 11 and 0.56 ± 0.64 µg/dl, respectively; % global DNA methylation was 2.8 ± 1.1% (ranging from 1.1 to 6.5%). B-Pb and P-Pb concentrations were significantly correlated. Furthermore, a marked association was noted between Pb biomarkers and DNA global methylation. Taken together, our data demonstrated that Pb exposure induced alterations on DNA global methylation in workers who were exposed to the metal and consequently may result in disturbances in the regulation of gene expression, leading to potentially several health adverse effect outcomes.

Made available in DSpace on 2018-12-11T17:23:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-05-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Nanotechnology is a growing branch of science that deals with the development of structural features bearing at least one dimension in the nano range. More specifically, nanomaterials are defined as objects with dimensions that range from 1 to 100 nm, which give rise to interesting properties. In particular, silver and titanium nanoparticles (AgNPs and TiNPs, respectively) are known for their biological and biomedical properties and are often used in consumer products such as cosmetics, food additives, kitchen utensils, and toys. This situation has increased environmental and occupational exposure to AgNPs and TiNPs, which has placed demand for the risk assessment of NPs. Indeed, the same properties that make nanomaterials so attractive could also prove deleterious to biological systems. Of particular concern is the effect of NPs on mitochondria because these organelles play an essential role in cellular homeostasis. In this scenario, this work aimed to study how AgNPs and TiNPs interact with the mitochondrial respiration chain and to analyze how this interaction interferes in the bioenergetics and oxidative state of the organelles after sub-chronic exposure. Mitochondria were exposed to the NPs by gavage treatment for 21 days to check whether co-exposure of the organelles to the two types of NPs elicited any mitochondrion-NP interaction. More specifically, male Wistar rats were randomly assigned to four groups. Groups I, II, III, and IV received mineral oil, TiNPs (100 μg/kg/day), AgNPs (100 μg/kg/day), and TiNPs + AgNPs (100 μg/kg/day), respectively, by gavage. The liver was immediately removed, and the mitochondria were isolated and used within 3 h. Exposure of mitochondria to TiNPs + AgNPs lowered the respiratory control ratio, causing an uncoupling effect in the oxidative phosphorylation system. Moreover, both types of NPs induced mitochondrial swelling. Extended exposure of mitochondria to the NPs maintained increased ROS levels and depleted the endogenous antioxidant system. The AgNPs and TiNPs acted synergistically—the intensity of the toxic effect on the mitochondrial redox state was more significant in the presence of both types of NPs. These findings imply that the action of the NPs on mitochondria underlie NP toxicity, so future application of NPs requires special attention. Faculdade de Ciências Farmacêuticas de Ribeirão Preto Departamento de Análises Clínicas Toxicológicas e Bromatológicas Universidade de São Paulo, Av. Bandeirantes, 3900, Bairro Monte Alegre Departamento Bioprocessos e Biotecnologia Faculdade de Ciências Agronômicas Fazenda Experimental de Lageado Universidade Estadual Paulista “Júlio de Mesquita Filho” Instituto de Ciência Engenharia e Tecnologia Universidade Federal dos Vales do Jequitinhonha e Mucuri Faculdade de Filosofia Ciências e Letras de Ribeirão Preto Departamento de Química Universidade de São Paulo, Avenida do Café s/n° National Institute for Alternative Technologies of Detection Toxicological Evaluation and Removal of Micropollutants and Radioactives (INCT-DATREM) Unesp Institute of Chemistry, P.O. Box 355 Departamento Bioprocessos e Biotecnologia Faculdade de Ciências Agronômicas Fazenda Experimental de Lageado Universidade Estadual Paulista “Júlio de Mesquita Filho” National Institute for Alternative Technologies of Detection Toxicological Evaluation and Removal of Micropollutants and Radioactives (INCT-DATREM) Unesp Institute of Chemistry, P.O. Box 355

Aquatic monitoring is an important tool for identifying potential compounds in rivers that may damage the environment. Here, we evaluate the potential genotoxic effects of water samples from São Francisco River (Brazil) using the micronuclei (MN) assay in resident species, Astyanax paranae. Four seasonal collections occurred between the years 2009 and 2010, at three locations between two nearby cities in the region. It was clearly observed an increase of MN frequency in fish caught in the river. This result is most likely due to the sewage contamination from the treatment plant, the waste pesticides from crops and the lack of riparian vegetation along the river, especially during the winter when there was a significant increase in the frequencies of MN. These results indicate that compounds in waters from São Francisco River may have genotoxic effects and consequently, cause damage to the environment as well as to human health.

Bixin is a carotenoid found in the seeds of Bixa orellana L., a plant native to tropical America that is used in the food industry. The aim of this study was to investigate the effect of bixin on DNA damage and pre-neoplastic lesions induced by 1,2-dimethylhydrazine (DMH) in the liver and colon of Wistar rats. The animals received bixin at daily doses of 0.1, 1.0 and 10 mg/kg body weight (bw) by gavage. For the assessment of DNA damage in hepatocytes and colon cells with the comet assay, the administration of bixin was for 7 days. The animals received a single subcutaneous injection of 25 mg/kg bw of DMH, and were euthanized 4 h later. For the evaluation of the frequency of aberrant crypt foci (ACF), the animals were treated with the different doses of bixin for 4 weeks. Four doses of 40 mg/kg bw DMH, two doses in the first week and two doses in the second week, were administered and euthanasia occurred at 4 weeks after the beginning of treatment. Bixin reduced the frequency of DNA damage in hepatocytes at the highest two doses tested (1.0 and 10 mg/kg bw). On the other hand, no differences in the frequency of DNA damage in colon cells were observed between animals treated with bixin plus DMH and those treated with DMH alone. In addition, the frequency of ACF did not differ significantly between the group treated with bixin plus DMH and the DMH group. The results suggest that bixin does not suppress the formation of ACF, indicating the absence of a protective effect against colon carcinogenesis.

The leaves of coca (Erythroxylum coca var. coca), a South American shrub which contains cocaine, other alkaloids and phenolics are widely used by indigenous populations of the Andes. It is currently not known if coca consumption causes genotoxic effects in humans. This information is important to predict potential long-term toxic effects such as cancer induction. Therefore, the buccal cytome assay was used to analyze oral cells from 45 uni- and bilateral chewers and 23 controls living in the Altiplano of the Peruvian Andes. In total, 123,471 cells were evaluated from chewers and 57,916 from controls. Information concerning the consumption levels and habits and also use of lime were collected with questionnaires. Chewing of the leaves did not induce nuclear anomalies reflecting genetic damage such as micronuclei (MNi) and nuclear buds; in the highest exposure group (but not in the overall group) even a significant decrease in the frequencies of cells with MNi (by 64 %) was observed. However, we found significantly elevated levels of other nuclear anomalies (karyorrhexis and karyolysis) which reflect cytotoxic effects in the coca users. The frequencies of these anomalies increased with the daily consumption and when lime was used to improve the release of the alkaloids. In contrast to other chewing habits (betel, tobacco and khat), consumption of coca leaves does not induce genetic instability in cells from the oral cavity and our findings indicate that no adverse health effects take place in chewers which are associated with DNA damage. However, the significant increase in certain anomalies shows that acute toxic effects are caused by coca consumption.

Over the last decades, the presence of methylmercury (MeHg) in the Amazon region of Brazil and its adverse human health effects have given rise to much concern. The biotransformation of MeHg occurs mainly through glutathione (GSH) in the bile mediated by conjugation with glutathione S-transferases (GST). Epidemiological evidence has shown that genetic polymorphisms may affect the metabolism of MeHg. The aim of this study was to evaluate the association between GST polymorphisms, GSH, and Hg levels in blood (B-Hg) and in hair (H-Hg) of an Amazon population chronically exposed to the metal through fish consumption. Blood and hair samples were collected from 144 volunteers (71 men, 73 women). B-Hg and H-Hg levels were determined by inductively coupled plasma-mass spectrometry, and GSH levels were evaluated by a spectrophotometric method. GSTM1 and T1 genotyping evaluation were carried out by multiplex polymerase chain reaction (PCR). Mean levels of B-Hg and H-Hg were 37.7 ± 24.5 μg/L and 10.4 ± 7.4 μg/g, respectively; GSH concentrations ranged from 0.52 to 2.89 μM/ml of total blood. Distributions for GSTM1/T1, GSTM1/GSTT1*0, GSTM1*0/T1, and GSTM1*0/GSTT1*0 genotypes were 35.4, 22.2, 25.0, and 17.4%, respectively. GSTT1 genotype carriers presented lower levels of B-Hg and H-Hg when compared to other genotypes carriers. In addition, GSTM1*0/GSTT1*0 individuals presented higher Hg levels in blood and hair than subjects presenting any other genotypes. There appeared to be no evidence of an effect of polymorphisms on GSH levels. Therefore, our data suggest that GST polymorphisms may be associated with MeHg detoxification.

Populations in the Amazon are exposed to organic mercury via consumption of contaminated foods. These ethnic groups consume a specific plant seed "annatto" which contains certain carotenoids. The aim of this study was to find out if these compounds (bixin, BIX and norbixin, NOR), protect against DNA-damage caused by the metal. Therefore, rats were treated orally with methylmercury (MeHg) and with the carotenoids under conditions that are relevant to humans. The animals were treated either with MeHg (30 μg/kg/bw/day), BIX (0.1-10 mg/kg/bw/day), NOR (0.01-1.0 mg/kg/bw/day) or combinations of the metal compound and the carotenoids consecutively for 45 days. Subsequently, the glutathione levels (GSH) and the activity of catalase were determined, and DNA-damage was measured in hepatocytes and leukocytes using single cell gel electrophoresis assays. Treatment with the metal alone caused a decrease in the GSH levels (35%) and induced DNA damage, which resulted in increased DNA migration after electrophoresis in liver and blood cells, whereas no effects were seen with the carotenoids alone. When BIX or NOR were given in combination with organic mercury, the intermediate and the highest concentrations of the carotenoids (1.0 and 10.0 mg/kg/bw/day BIX and 0.1 and 1.0 mg/kg/bw/day NOR) protected against DNA-damage. Furthermore, we found with both carotenoids, a moderate increase in the GSH levels in both metal-treated and untreated animals, while the activities of catalase remained unchanged. Our results indicate that consumption of BIX and NOR may protect humans against the adverse health effects caused by exposure to organic mercury.

Several epidemiological and experimental studies has been reported that lutein (LT) presents antioxidant properties. Aim of the present study was to investigate the protective effects of LT against oxidative stress and DNA damage induced by cisplatin (cDDP) in a human derived liver cell line (HepG2). Cell viability and DNA-damage was monitored by MTT and comet assays. Moreover, different biochemical parameters related to redox status (glutathione, cytochrome-c and intracellular ROS) were also evaluated. A clear DNA-damage was seen with cDDP (1.0μM) treatment. In combination with the carotenoid, reduction of DNA damage was observed after pre- and simultaneous treatment of the cells, but not when the carotenoid was added to the cells after the exposure to cDDP. Exposure of the cells to cDDP also caused significant changes of all biochemical parameters and in co-treatment of the cells with LT, the carotenoid reverted these alterations. The results indicate that cDDP induces pronounced oxidative stress in HepG2 cells that is related to DNA damage and that the supplementation with the antioxidant LT may protect these adverse effects caused by the exposure of the cells to platinum compound, which can be a good predict for chemoprevention.

Aim of this study was to investigate the cytotoxic and genotoxic properties of inorganic and organic mercury compounds, i.e., HgCl(2) and methylmercury (MeHg). In addition, the DNA-protective and antioxidant effects of the flavonoid quercetin (QC) were studied. All experiments were conducted with human-derived liver cells (HepG2), which possess antioxidant and drug-metabolizing enzymes in an inducible form. 8-Hydroxydeoxyguanosine (8-OHdG) and comet formation were monitored as endpoints of DNA damage. The impact of the metal compounds on the redox status was also investigated, since it is assumed that their toxic effects are due to oxidative damage. A number of biochemical parameters related to oxidative stress, namely glutathione, malondialdehyde, protein carbonyl and formation of reactive oxygen species (ROS) were measured after treatment of the cells with the mercury compounds in the presence and absence of quercetin. To elucidate the mechanisms that underlie the effects of QC, three protocols (pre-, simultaneous and post-treatment) were used. Both mercury compounds (range 0.1-5.0μM) caused induction of DNA migration and formation of 8-OHdG. In combination with the flavonoid (range 0.1-5.0μM), DNA-protective effects of QC were observed after pre- and simultaneous treatment but not when the flavonoid was added after treatment with the metal compounds. Exposure to the metal compounds led also to substantial changes of all parameters of the redox status and co-treatment experiments with QC showed that these alterations are reversed by the flavonoid. Taken together, the results of our experiments indicate that these two mercury compounds cause DNA damage and oxidative stress in human-derived liver cells and that the flavonoid reduces these effects. Since the concentrations of the metals and of the flavonoids used in the present work reflect human exposure, our findings can be taken as an indication that QC may protect humans against the adverse effects caused by the metal.

The flavonoid quercetin and its derivative rutin were investigated for genotoxicity/antigenotoxicity activity in human hepatoma HepG2 cells using the comet assay. The extract cytotoxicity was evaluated using the trypan blue exclusion dye method with quercetin and rutin concentrations ranging from 0.1 to 200.0 μg/mL of culture medium. Three minor non-cytotoxic concentrations were chosen to evaluate the genotoxicity and antigenotoxicity of the flavonoids (0.1, 1.0 and 5.0 μg/mL) through comet assay. The cultures were treated with three different concentrations of rutin or quercetin (genotoxicity) or their association with Aflatoxin B1 (AFB1), methyl methanesulfonate (MMS) or doxorubicin (DXR) (antigenotoxicity test) in three protocols: pre-treatment, simultaneous treatment and post-treatment. The cell cultures were also treated with 1% DMSO (control group), AFB1, MMS and DXR (positive-control). Statistical analyses were performed using ANOVA and Dunnett's test (p ≤ 0.05). Quercetin at concentrations higher than 10.0 μg/mL or rutin higher than 50.0 μg/mL exhibited a cytotoxic effect on the cells, showing that quercetin is more cytotoxic than rutin. Furthermore, neither compound was able to induce genotoxicity in the concentrations evaluated. On the other hand, both flavonoids reduced DNA damage induced by AFB1, MMS and DXR in all treatment protocols.

Annatto (AN), a natural food colorant rich in carotenoids, has been reported as being an effective antioxidant, but little is known about its potential chemopreventive properties. In this study, we evaluated the ability of AN to protect human hepatoma cells (HepG2) from micronucleus (MN) induction against three different mutagens: benzo(a)pyrene (B(a)P), doxorubicin (DXR), and methyl methanesulfonate (MMS). In an attempt to clarify the possible mechanism of antimutagenicity of AN, three protocols of treatment were applied (pretreatment; simultaneous treatment, and post-treatment with AN following treatment with the mutagens). Also, cells exposed only to AN were assayed for cytotoxicity and mutagenicity. A dosage up to 10 μg/ml of AN was devoid of mutagenic activity. Protective effects were seen on micronuclei induced by B(a)P and DXR using pre and simultaneous treatment, but AN had no significant effect on MN induction by MMS in any of the protocols. Our results also show that exposure of cells to concentrations of AN higher than 10 μg/ml decreased cell viability. Taken together, our findings indicate that AN presents antimutagenic activity in vitro, but its protective effect is dependent on the mutagen and on type of treatment suggesting its potential use as a chemopreventive agent. Environ. Mol. Mutagen. 2009. © 2009 Wiley-Liss, Inc.

In this study we examined the possible antigenotoxic effect of selenium (Se) in rats chronically exposed to low levels of methylmercury (MeHg) and the association between glutathione peroxidase (GSH-Px) activity and DNA lesions (via comet assay) in the same exposed animals. Rats were divided into six groups as follows: (Group I) received water; (Group II) received MeHg (100 mug/day); (Group III) received Se (2 mg/L drinking water); (Group IV) received Se (6 mg/L drinking water); (Group V) received MeHg (100 mug/day) and Se (2 mg/L drinking water); (Group VI) received MeHg (100 mug/day) and Se (6 mg/L drinking water). Total treatment time was 100 days. GSH-Px activity was determined spectrophotometrically and DNA damage was determined by comet assay. Mean GSH-Px activity in groups I, II, III, IV, V and VI were, respectively: 40.19 +/- 17.21; 23.63 +/- 6.04; 42.64 +/- 5.70; 38.50 +/- 7.15; 34.54 +/- 6.18 and 41.39 +/- 11.67 nmolNADPH/min/gHb. DNA damage was represented by a mean score from 0 to 300; the results for groups I, II, III, IV, V and VI were, respectively: 6.87 +/- 3.27; 124.12 +/- 13.74; 10.62 +/- 3.81; 13.25 +/- 1.76; 86.87 +/- 11.95 and 76.25 +/- 7.48. There was a significant inhibition of GSH-Px activity in group II compared with group I (P0.05). Groups V and VI did not show a difference in enzyme activity compared with groups III and IV, showing the possible protective action of Se. Comet assay presented a significant difference in DNA migration between group II and group I (P0.0001). Groups V and VI showed a significant reduction in MeHg-induced genotoxicity (P0.001) when compared with group II. A negative correlation (r = -0.559, P0.05) was found between GSH-Px activity and DNA lesion, showing that the greater the DNA damage, the lower the GSH-Px activity. Our findings demonstrated the oxidative and genotoxic properties of MeHg, even at low doses. Moreover, Se co-administration reestablished GSH-Px activity and reduced DNA damage.

The use of plants for the treatment of diseases continues to rise although there are few studies providing proof of these effects. One of these plants is the Anacardium occidentale, popularly known as the cashew. The present study evaluated the possible genotoxic and protective activities of cashew stem bark methanolic extract, in vitro, using methyl methanesulfonate (MMS) as a positive control, to compare possible mechanisms of DNA damage induction in the Comet assay. The antigenotoxicity protocols used were pre, simultaneous and post-treatment in relation to MMS. In genotoxicity and antigenotoxicity assessments, besides MMS, PBS was used as the negative control and three concentrations of the A. occidentale extract (500 microg/mL, 1000 microg/mL and 2000 microg/mL) were used on Chinese hamster lung fibroblasts (V79 cells). The Comet assay revealed that the two lowest concentrations tested presented no genotoxic activity, whereas the highest presented genotoxicity. All of the concentrations showed protective activity in simultaneous and post-treatment in relation to MMS. Further studies are required to identify the substances that comprise the extract and more clearly comprehend the antigenotoxic mechanism detected in this study.

Plants remain to be a great source of medicines for humanity. Among them is the Anacardium occidentale L. species, popularly known as the cashew, which has several therapeutic indications, such as cicatrizing, antihypertensive, hypoglycemic and antitumoral properties. The objective of the present work was to assess the mutagenicity and antimutagenicity of cashew stem bark methanolic extract (CSBME) on cell cultures of Chinese hamster lung fibroblasts (V79). The cultures were treated with different concentrations of the CSBME (500, 1000 and 2000 μg/mL) or with the extract associated with doxorubicin (DXR, 0.75 μg/mL) during the cell cycle phases G1, S, and G2 and throughout continuous treatment. Apart from these treatments, the cell cultures were also treated with PBS (negative-control) and DXR (positive-control). The data obtained in the chromosome aberrations (CA) test showed a significant reduction in CA frequency in the cultures treated with DXR and extract in comparison with those that received only DXR during the cell cycle phases G1 and S and throughout the entire cycle, as well as the absence of mutagenicity in all the treatments realized. The antimutagenic effect observed in this work reinforces the presence of the previously described therapeutic properties of cashew and indicates the safe use of this extract.

The lasiodiplodan (LS) is a β-(1→6)-d-glucan produced by the fungus Lasiodiplodia theobromae and some of the biological activities of LS were reported as hypoglycemic, anticoagulant, anti-proliferative and anticancer action; however, its effects on DNA instability and modulation of gene expression are still unclear. Aims of study were investigate the genotoxic effects of lasiodiplodan, and its protective activity against DNA damage induced by doxorubicin (DXR) and its impact on the expression of genes associated with DNA damage and inflammatory response pathways. Therefore, Wistar rats were treated (15 days) orally with LS (5.0; 10 and 20mg/kg bw) alone and in combination with DXR (15mg/kg bw; administrated intraperitoneally on 14th day) as well as their respective controls: distilled water and DXR. Monitoring of DNA damage was assessed by comet and micronucleus (MN) assays and gene expression was evaluated by PCR-Arrays. Treatments with LS alone did not induce disturbances on DNA; when LS was given in combination with DXR, comet and MN formations were reduced to those found in the respective controls. Moreover, LS was able to reduce the disturbances on gene expressions induced by DXR treatment, since the animals that receive LS associated with DXR showed no alteration in the expression of genes related to DNA damage response. Also, DXR induced several up- and down-regulation of several genes associated to inflammatory process, while the animals that received LS+DXR had their gene expression patterns similar to those found in the control group. In conclusion, our results showed that LS did not induce disturbances on DNA stability and significantly reduce the DNA damage and inflammation caused by DXR exposure. In addition, we give further information concerning the molecular mechanisms associated to LS protective effects which seems to be a promising nutraceutical with chemopreventive potential.

O mercúrio (Hg) é um dos metais mais tóxicos presente no meio ambiente e o principal mecanismo relacionado à sua toxicidade é a indução do estresse oxidativo; sua forma orgânica, metilmercúrio (MeHg) é a que apresenta maior toxicidade. A exposição ao Hg ocorre principalmente através da inalação por trabalhadores ocupacionalmente expostos em diversas indústrias e/ou através do consumo de peixes e outros alimentos aquáticos contendo este metal, como por exemplo, populações amazônicas que estão expostas ao MeHg, via dieta, através do consumo de peixes contaminados. Por outro lado, é pressuposto que alimentos ricos em antioxidantes possam prevenir os efeitos adversos à saúde causados pela exposição ao Hg. O flavonóide quercetina (QC) é o principal polifenol da dieta humana, encontrado principalmente em cebola e frutas cítricas e os carotenóides bixina (BIX) e norbixina (NOR) estão presentes em grandes quantidades no urucum, o qual é amplamente utilizado como condimento no Brasil. Assim sendo, o presente trabalho teve por objetivo avaliar os possíveis efeitos protetores do flavonóide QC e dos carotenóides BIX e NOR contra os diversos efeitos adversos causados pelo cloreto de mercúrio (HgCl2) e MeHg, em modelos experimentais in vitro e in vivo. Para tal, culturas de células de hepatoma humano (HepG2) e ratos machos Wistar foram expostos a diversas concentrações do metal, dos fitoquímicos bem como à suas associações. Determinações das concentrações de glutationa, malondialdeído, proteínas carboniladas, atividades das enzimas antioxidantes catalase e glutationa-peroxidase os quais refletem o estado redox das células e monitoramento do dano no material genético pelo uso do ensaio do cometa e determinações dos níveis de 8-hidroxi-2-deoxiguanosina foram realizados no presente estudo. Os resultados obtidos indicam que o Hg causa claros efeitos genotóxicos e leva a uma serie de alterações de parâmetros bioquímicos relacionados ao estado redox das células, in vitro e in vivo. Além disso, foi evidenciado que fitoquímicos, os quais são comumente encontrados na dieta de seres humanos, denominados QC, BIX e NOR protegem contra a instabilidade genética causada pelo metal e restabelece os distúrbios do estado redox das células causados pela exposição ao Hg. Mercury (Hg) is one of the most hazardous metals in the environment and the major process responsible for its toxicity is oxidative damage; its organic form methylmercury (MeHg) presents the highest toxicity. The main way of exposition to Hg is through inhalation by workers occupationally exposed in several industries and/or through consumption of fishes and other aquatic food with the metal, as Amazonian populations which are exposed to MeHg, via diet, by consumption of contaminated fishes. On the other hand, it is conceivable that antioxidants may play a protective role in the prevention of adverse effects of Hg. The flavonoid quercetin (QC) is the most abundant polyphenol of the human diet, found mainly in onions and citric fuits and the carotenoids bixin (BIX) and norbixin (NOR) are present in high concentrations in annatto, which is widely used as flavoring in Brazil. Therefore, the present study aims to evaluate the possible protective effects of the flavonoid QC and of the carotenoids BIX and NOR against the adverse effects caused by mercury chloride (HgCl2) and MeHg, in experimental models in vitro and in vivo. For this, human hepatoma cells (HepG2) cultures and male rats Wistar were exposed to several concentrations of the metal, of the phytochemicals as well as their associations. Determination of concentrations of glutathione, malondialdehyde, carbonil proteins, activity of the antioxidant enzymes catalase and glutathione-peroxidase, which reflect the redox status of the cells and monitoring of DNA-damage by use of comet assay and measurements of 8-hydroxi-2-deoxyguanosine levels were carried out in the present study. The results indicate that Hg cause clear genotoxic effects and lead to several alterations of biochemical parameters related to redox status of the cells, in vitro and in vivo. Moreover, it was observed that pythochemicals commonly found in the human diet, namely QC, BIX and NOR counteract the genetic instability induced by the metal and restore the disturbances of redox status of the cells caused by Hg exposition.

Lead (Pb) is a toxic metal that is widely used by metallurgical industries such as car battery recycling. Exposure to the metal may modify the redox status of the cells and consequently result in changes in activities of important enzymes such as delta-aminolevulinic acid dehydratase (ALAD) and glutathione peroxidase (GPx). Similarly, genetic polymorphisms may modulate the activities of enzymes related to detoxification processes of the metal and may modify Pb body burden. Therefore, the aims of the present study were (i) to evaluate the correlation between blood lead levels (BLL) and activities of the enzymes ALAD and GPx, and (ii) to determine whether activities of these enzymes may be influenced by polymorphisms in ALAD and GPx genes in Brazilian automotive battery workers chronically exposed to Pb, as well as the effects of these polymorphisms on BLL. Our study included 257 participants; BLL were determined by inductively couple plasma-mass spectrometry (ICP-MS), and the activities of the enzymes ALAD and GPx were quantified spectrophotometrically; and genotyping of ALAD (rs1800435) and GPx-1 (rs1800668) polymorphisms was performed by TaqMan assays (real-time polymerase chain reaction, RT-PCR). Significant negative correlations were found between BLL and ALAD activity. Subjects who carried at least one polymorphic allele for ALAD gene displayed markedly lower ALAD activities, while no significant effect was observed regarding GPx-1 polymorphism and activity of the same enzyme. Further, ALAD and GPx-1 polymorphisms exerted no marked influence on BLL. Taken together, our results showed that BLL affected ALAD but not GPx activities, and these were not modulated by polymorphisms in ALAD and GPx gene. Further, the rs1800435 SNP showed a tendency to modulate ALAD activity, while the rs1800668 SNP did not modulate GPx activity in Brazilian automotive battery workers exposed to Pb.

The use of phytochemicals has been widely used as inexpensive approach for prevention of diseases related to oxidative damage due to its antioxidant properties. One of dietary flavonoids is chrysin (CR), found mainly in passion fruit, honey, and propolis. Methylmercury (MeHg) is a toxic metal whose main toxic mechanism is oxidative damage. Thus, the study aimed to evaluate the antioxidant effects of CR against oxidative damage induced by MeHg in Wistar rats. Animals were treated with MeHg (30 µg/kg/bw) in presence and absence of CR (0.10, 1.0, and 10 mg/kg/bw) by gavage for 45 days. Glutathione (GSH) in blood was quantified spectrophotometrically and for monitoring of DNA damage, comet assay was used in leukocytes and hepatocytes. MeHg led to a significant increase in the formation of comets; when the animals were exposed to the metal in the presence of CR, higher concentrations of CR showed protective effects. Moreover, exposure to MeHg decreased the levels of GSH and GSH levels were restored in the animals that received CR plus MeHg. Taken together the findings of the present work indicate that consumption of flavonoids such as CR may protect humans against the adverse health effects caused by MeHg.

There have been reports of genetic effects affecting the metabolism of Hg and Pb individually, and thus modulating their toxicities. However, there is still a knowledge gap with respect to how genetics may influence the toxicities of these toxic metals during a co-exposure scenario. This present study is therefore aimed at investigating the effects of polymorphisms in genes (GSTM1, GSTT1, GSTP1, GCLM, GCLC, GPx1, ALAD, VDR and MDR1) that have been implicated in Hg and Pb metabolisms affects the kinetics of these metals, as well as various blood antioxidant status parameters: MDA and GSH, and the activities of CAT, GPx and ALAD among populations that have been co-exposed to both Hg and Pb. Study subjects (207 men; 188 women) were from an Amazonian population in Brazil, exposed to Hg and Pb from diet. The blood levels of Hg and Pb were determined by ICP-MS while genotyping were performed by PCR assays. The median values of Hg and Pb in blood were 39.8µg/L and 11.0µg/dL, respectively. GSTM1, ALAD and VDR polymorphisms influenced Hg in blood (β=0.17; 0.37 and 0.17; respectively, p

The aim of the present study was to evaluate possible effects of endothelial nitric oxide synthase (eNOS) polymorphisms on systolic (SBP) and diastolic blood pressure (DBP) and on nitrite levels in plasma (NitP) in a population coexposed to methylhemoglobin (MeHg) and lead (Pb) in the Amazonian region, Brazil. Plasmatic levels of hemoglobin Hg (HgP) and Pb (PbP) were determined by inductively coupled plasma-mass spectrometry, whereas NitP were quantified by chemiluminescence. Genotyping was performed by conventional and restriction fragment length polymorphism-polymerase chain reaction assay. The population age ranged from 18 to 87 years (mean 40 ± 16), and the distribution between the sexes was homogenous (63 men and 50 women). Mean HgP and PbP were 7.1 ± 6.1 and 1.1 ± 1.1 µg L(-1), respectively. PbP was correlated to SBP and DBP, whereas no effects were observed for HgP on blood pressure. Subjects carrying the 4b allele in intron 4 presented greater SBP and DBP compared with those who had the 4a4a genotype. In addition, interactions between alcohol consumption and the -786 T/C polymorphism were observed on NitP, i.e., individuals carrying the polymorphic allele and drinkers had lower NitP. Taken together, our data give new insights concerning the genetic effects of eNOS polymorphisms on biomarkers related to cardiovascular status in populations coexposed to Hg and Pb.

This study aims to evaluate the effects of polymorphisms in glutathione (GSH-) related genes (GSTM1,GSTT1,GSTP1,GCLM, andGCLC) in the distribution of Hg in the blood compartments in humans exposed to methylmercury (MeHg). Subjects (n=88), exposed to MeHg from fish consumption, were enrolled in the study. Hg species in the plasma compartment were determined by LC-ICP-MS, whereas genotyping was performed by PCR assays. Mean total Hg levels in plasma (THgP) and whole blood (THgB) were10±4.2and37±21, whereas mean evels of plasmatic MeHg (MeHgP), inorganic Hg (IHgP), and HgP/HgB were4.3±2.9,5.8±2.3 µg/L, and0.33±0.15, respectively.GSTM1andGCLCpolymorphisms influence THgP and MeHgP (multivariate analyses,P<0.050). Null homozygotes forGSTM1showed higher THgP and MeHgP levels compared to subjects withGSTM1(THgPβ=0.22,P=0.035; MeHgPβ=0.30,P=0.050) and persons carrying at least one T allele forGCLChad significant higher MeHgP (β=0.59,P=0.046). Also, polymorphicGCLMsubjects had lower THgP/THgB than those with the nonvariant genotype. Taken together, data of this study suggest that GSH-related polymorphisms may change the metabolism of MeHg by modifying the distribution of mercury species iin plasma compartment and the HgP/HgB partitioning.

Methylmercury (MeHg) toxicity may vary widely despite similar levels of exposure. This is hypothetically related to genetic differences in enzymes metabolizing MeHg. MeHg causes oxidative stress in experimental models but little is known about its effects on humans. The aims of the present study was to evaluate the effects of polymorphisms in glutathione (GSH)-related genes (GSTM1, GSTT1, GSTP1 and GCLM) on Hg concentrations in blood and hair, as well as MeHg-related effects on catalase (CAT) and glutathione-peroxidase (GPx) activity and GSH concentrations. Study subjects were from an Amazonian population in Brazil chronically exposed to MeHg from fish. Hg in blood and hair were determined by ICP-MS, CAT, GPx and GSH were determined by spectrophotometry, and multiplex PCR (GSTM1 and GSTT1) and TagMan assays (GSTP1 and GCLM) were used for genotyping. Mean Hg concentrations in blood and hair were 48 +/- 36 mu g/L and 14 +/- 10 mu g/g. Persons with the GCLM-588 IT genotype had lower blood and hair Hg than did C-allele carriers (linear regression for Hg in blood beta = -0.32, p = 0.017; and hair beta = -0.33; p = 0.0090; adjusted for fish intake, age and gender). GSTM1*0 homozygous had higher blood (beta = 0.20; p = 0.017) and hair Hg (hair beta = 0.20; p = 0.013). Exposure to MeHg altered antioxidant status (CAT:beta = -0.086; GSH:beta = -0.12; GPx:beta = -0.16; all p < 0.010; adjusted for gender, age and smoking). Persons with GSTM1*0 had higher CAT activity in the blood than those with GSTM1. Our data thus indicate that some GSH-related polymorphisms, such as GSTM1 and GCLM may modify MeHg metabolism and Hg-related antioxidant effects. (C) 2013 Elsevier BY. All rights reserved. (Less)

Aim of the study was to find out whether consumption of quercetin (QC), an abundant flavonoid in the human diet, protects against DNA damage caused by exposure to organic mercury. Therefore, rats were treated orally with methylmercury (MeHg) and the flavonoid with doses that reflect the human exposure. The animals received MeHg (30 μg/kg/bw/day), QC (0.5–50 mg/kg/bw/day), or combinations of both over 45 days. Subsequently, the glutathione levels (GSH) and the activities of glutathione peroxidase (GPx) and catalase (CAT) were determined, and DNA damage was measured in hepatocytes and peripheral leukocytes in single cell gel electrophoresis assays. MeHg decreased the concentration of GSH and the activity of GPx by 17 and 12%, respectively and caused DNA damage to liver and blood cells, while with QC no such effects were seen. When the flavonoid was given in combination with MeHg, the intermediate and the highest concentrations (5.0 and 50.0 mg/kg/bw/day) were found to cause DNA protection; DNA migration was reduced by 54 and 65% in the hepatocytes and by 27 and 36% in the leukocytes; furthermore, the reduction in GSH and GPx levels caused by MeHg treatment was restored. In summary, our results indicate that consumption of QC-rich foods may protect Hg-exposed humans against the adverse health effects of the metal.

The present study evaluates a possible protective effect of fish oil against oxidative damage promoted by methylmercury (MeHg) in sub-chronically exposed rats. Reduced glutathione peroxidase and catalase enzyme activity and reduced glutathione levels were observed in MeHg-exposed animals compared to controls. Methylmercury exposure was also associated with DNA damage. Administration of fish oil to the methylmercury-exposed animals did not ameliorate enzyme activity or glutathione levels. On the other hand, a significant DNA protective effect (about 30%) was observed with fish oil treatment. There were no differences in the total mercury concentration in rat liver, kidney, heart or brain after MeHg administration with or without fish oil co-administration. Histopathological analyses showed a significant leukocyte infiltration in rat tissues after MeHg exposure, but this effect was significantly reduced after co-administration of fish oil. Taken together, our findings demonstrate oxidative damage even after low-level MeHg exposure and the protective effect of fish oil. This protection seems not to be related to antioxidant defenses or mercury re-distribution in rat tissues. It is probably due to the anti-inflammatory effects of fish oil.

The Miconia genus, a plant widely used for medicine, occurs in tropical America and its extracts and isolated compounds have demonstrated antibiotic, antitumoral, analgesic and antimalarial activities. However, no study concerning its genotoxicity has been conducted and it is necessary to determine its potential mutagenic effects to develop products and chemicals from these extracts. This study assessed the cytotoxicity, mutagenicity and the protective effects of methanolic extracts from Miconia species on Chinese hamster lung fibroblast cell cultures (V79). The cytotoxicity was evaluated using a clonogenic assay. Cultures exposed to the extract of Miconia albicans up to a concentration of 30 μg/mL, M. cabucu up to 40 μg/mL, M. albicans up to 40 μg/mL and M. stenostachya up to 60 μg/mL exhibited a cytotoxic effect on the cells. The clonogenic assay used three non-cytotoxic concentrations (5, 10 and 20 μg/mL) to evaluate mutagenicity and antimutagenicity of the extracts. Cultures were treated with these three extract concentrations (mutagenicity test) or the extract associated with doxorubicin (DXR) (antimutagenicity test) in three protocols (pre-, simultaneous and post-treatments). Distilled water and DXR were used as negative and positive controls, respectively. In the micronucleus (MN) test, a significant reduction was observed in MN frequency in cultures treated with DXR and extracts compared to those receiving only DXR; a significant reduction was also observed for the presence of mutagenicity in all treatments. This study confirmed the safe use of Miconia extracts at the concentrations tested and reinforced the therapeutic properties previously described for Miconia species by showing their protective effects on doxorubicin-induced mutagenicity.

Increased risk of hypertension after methylmercury (MeHg) exposure has been suggested. However, the underlying mechanisms are not well explored. In this paper, we have analyzed whether sub-chronic exposure to MeHg increases systolic blood pressure even at very low levels. In addition, we analyzed if the methylmercury-induced hypertension is associated with a decreased plasmatic nitric oxide levels and with a dysregulation of the activities of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT), as well as the levels of MDA and glutathione. For this study, Wistar rats were treated with methylmercury chloride (100 microg/kg per day) or vehicle. Total treatment time was 100 days. Malondialdehyde (MDA) and circulating NOx levels and superoxide dismutase (SOD) and catalase (CAT) activities were determined in plasma, whereas glutathione levels were determined in erythrocytes. Our results show that long-term treatment at a low level of MeHg affected systolic blood pressure, increasing and reducing the levels of plasmatic MDA and NOx, respectively. However, the activity of SOD did not decrease in the MeHg exposed group when compared to the control. We found a negative correlation between plasmatic nitrite/nitrate (NOx) levels and systolic blood pressure (r = -0.67; P = 0.001), and a positive correlation between MDA and systolic blood pressure (r = 0.61; P = 0.03), thus suggesting increased inhibition of NO formation with the increase of hypertension. In conclusion, long-term exposure to a low dose of MeHg increases the systolic pressure and is associated, at least in part, with increased production of ROS as judged by increased production of malondialdehyde and depressed NO availability.

O uso de espécies vegetais para fins de tratamento e cura de doenças remonta o início da civilização, desde o momento em que o homem começou um longo percurso de manuseio, adaptação e modificação destes recursos naturais para seu próprio benefício. Dentre as plantas que continuam a ser uma grande fonte de medicamentos para a humanidade está a espécie Anacardium occidentale L., popularmente conhecida como cajueiro, o qual possui indicações terapêuticas variadas, tais como: propriedade cicatrizante, antihipertensivo, combate a distúrbios gástricos, controle do diabetes, combate a asmas e bronquites. Contudo, alguns estudos demonstraram atividade mutagênica para o extrato desta planta. Em faces às atividades já descritas para o cajueiro e com o objetivo de contribuir para um melhor esclarecimento de suas atividades biológicas, o presente trabalho teve por objetivo avaliar in vitro os possíveis efeitos citotóxico, genotóxico, mutagênico e protetor do extrato da casca do cajueiro, utilizando o ensaio do cometa e o teste de aberrações cromossômicas em cultura de células V-79. O teste de sobrevivência celular avaliou a citotoxicidade de diferentes concentrações do extrato da casca do caju (500, 1000, 2000, 3000, 4000, 5000 e 6000 ?g/mL de meio de cultura) e permitiu a escolha de três (500 ?g/mL, 1000 ?g/mL e 2000 ?g/mL de meio de cultura), as quais não apresentaram citotoxicidade, para a realização dos testes de genotoxicidade e mutagenicidade. Nos testes de aberrações cromossômicas e do cometa, foram utilizados, respectivamente, como agentes indutores de danos a doxorrubicina (DXR) e o metilmetanosulfonato (MMS) e como controle negativo, PBS. Nas avaliações das atividades protetoras utilizando o ensaio do cometa o extrato foi associado ao MMS em pré, pós e tratamento simultâneo e sua ação antimutagênica quando associado à DXR foi avaliada sobre a incidência de aberrações cromossômicas em tratamento simultâneo contínuo e nas fases G1, S e G2 do ciclo celular. Os resultados obtidos no teste de aberrações cromossômicas revelaram que nenhuma das três concentrações utilizadas apresentou efeito mutagênico em todos os protocolos de tratamentos utilizados e que, no teste de antimutagenicidade, o extrato da casca do cajueiro proporcionou efeito antimutagênico em todas as fases do ciclo celular testadas. Na fase G1 as concentrações de 500 e 2000 ?g/mL, bem como, a concentração de 1000 ?g/mL na fase S também apresentaram efeito protetor. O ensaio do cometa revelou que as duas menores concentrações utilizadas não apresentaram atividade genotóxica e a maior mostrou genotoxicidade baixa. Todas as concentrações apresentaram atividade protetora de danos no DNA causados pelo MMS em tratamento simultâneo e pós-tratamento, o que sugere que tal extrato possua possivelmente uma ação bio-antimutagênica. O fato do extrato do cajueiro não ter apresentado genotoxicidade na maioria das concentrações e protocolos avaliados e ter protegido as células V79 contra danos causados por agentes alquilantes (MMS) e oxidantes (DXR) fornecem maior segurança para a utilização terapêutica do mesmo e estimula a continuidade dos estudos visando contribuir para a compreensão dos mecanismos envolvidos em seu efeito protetor e identificação dos compostos bioativos encontrados neste extrato. The use of vegetable species in order to treat and cure diseases leads us back to the beginning of our civilization, to the moment in which man started a long journey of handling, adaptation and modification of these natural resources for his own benefit. Among the plants that continue to be a great source of medicine to the humanity is the Anacardium occidentale L., popularly known as cashew tree, which has several therapeutical indications, such as: scarred property, antihipertensive, gastric disturbance combat, diabetes control, asthma and bronchitis combat. However, some studies showed mutagenic activity for this plant?s extract. In the face of activities already described for the cashew and having as an aim to contribute for a better clarifying of its biological activities, the present work has as a goal to evaluate in vitro the possible citotoxity, genotoxicity, mutagenicity and protective effects of the cashew?s stem bark, using the comet assay and the cromossomic aberration test in cell V-79. The cell survival test evaluated the citotoxicity of different cashew?s stem bark extract concentrations (500, 1000, 2000, 3000, 4000, 5000 and 6000 ?g/mL of culture agent) and allowed the choice of three (500 ?g/mL, 1000 ?g/mL and 2000 ?g/mL of culture agent), which did not present citotoxity for the fulfillment of the genotoxicity and mutagenicity tests. In the cromossomic aberration and comet assays the doxorrubicine (DXR) and methyl metanosulfonate (MMS) were respectively used as damage inductor agents and, as negative control, PBS. In the protection activities using the comet assay, the extract was associated to the MMS in pre, post and simultaneous treatment and its antimutagenic action, when associated to DXR, was evaluated over the cromossomic aberrations incidence in simultaneous continuous treatments and in the phases G1, S and G2 of the cell cycle. The results obtained in the cromossomic aberration test revealed that none of the three concentrations that were used has showed mutagenic effect in all the treatment protocols used and that in the antimutagenicity test, the cashew?s stem bark provided antimutagenic effect in all phases of the cell cycles tested. In the G1 phase, the 500 and 2000 ?g/mL concentrations as well as the 1000 ?g/mL concentration in the S phase also presented protective effect. The comet assay revealed that the two minor concentrations used did not present genotoxic activity and that the major one showed low genotoxicity. All concentrations presented damage protection activity in the DNA caused by the MMS in simultaneous treatment and post-treatment, which suggests that such extract possibly has a bio-antimutagenic action. The fact that the cashew?s stem bark extract did not show genotoxicidade in the most of concentrations and protocols assessed and it has protected the V79 cells against damages caused by alquilant (MMS) and oxidant (DXR) agents gives us more security in its therapeutical usage and stimulates the continuity of the studies aiming to contribute to the understanding of the mechanism involved in its protective effect and identification of the bioactive compounds found in this extract.

Propolis has been used in folk medicine since ancient times and is known for its antimicrobial, antiparasitic, antiviral, anti-inflammatory, antitumoral and antioxidant properties. In view of the great therapeutic interest in propolis and the small number of studies regarding its mechanism of action, the aim of the present study was to evaluate the mutagenic and antimutagenic effects of propolis using Chinese hamster ovary cells. Parameters such as the frequency of chromosome aberrations and mitotic index were analyzed. The results showed that, on one hand, the highest propolis tested concentration displayed a small but significant increase in the frequency of chromosome aberrations, and on the other hand, it was observed that the lowest tested concentration significantly reduced the chromosome damage induced by the chemotherapeutic agent doxorubicin. The present results indicate that propolis shows the characteristic of a "Janus" compound, i.e., propolis is genotoxic at higher concentrations, while at lower concentrations it display a chemopreventive effect on doxorubicin-induced mutagenicity. Flavonoids may be the components of propolis responsible for its both mutagenic and antimutagenic effects, once these compounds may act either as pro-oxidant or as free radicals scavenger, depending on its concentration.

O chumbo (Pb) é um metal tóxico encontrado no ambiente e amplamente utilizado em diversos setores industriais, como na produção de baterias Pb-ácidas. Pode causar uma variedade de efeitos adversos à saúde humana, como distúrbios gastrointestinais, renais, neurológicos e hematopoiéticos, e estresse oxidativo. A toxicidade induzida pelo Pb é modulada por diversas proteínas e enzimas, além de sistemas antioxidantes e, neste sentido, é presumível que alterações genéticas possam influenciar na toxicocinética do metal no organismo. Assim, o objetivo deste trabalho foi avaliar o impacto de polimorfismos (SNPs) em genes relacionados à toxicocinética do Pb (ALAD, GPx1, GSR, GSS, GSTP1, HFE, SLC11A1, SLC11A2 e VDR) sobre as concentrações do metal no sangue (Pb-s), plasma (Pb-p) e urina (Pb-u) e sobre biomarcadores do estado redox, isto é, glutationa reduzida (GSH), catalase (CAT), glutationa peroxidase (GPx), glutationa S-transferase (GST) e 8-hidroxi-2\'-deoxiguanosina urinária (8-OHdG). 236 trabalhadores de fábricas de baterias automotivas e 40 indivíduos não-expostos ocupacionalmente ao Pb foram incluídos no estudo. As concentrações de Pb foram determinadas por espectrometria de massas com plasma acoplado indutivamente (ICP-MS) e as genotipagens realizadas através do método TaqMan, por meio da Reação em Cadeia da Polimerase (PCR) em Tempo Real. As atividades das enzimas sanguíneas foram avaliadas por espectrofotometria e as concentrações de 8-OHdG foram determinadas por cromatografia líquida acoplada à espectrometria de massas em tandem (LC-MS/MS). As médias ± desvios padrão de Pb-s, Pb-p e Pb-u no grupo exposto foram de 21 ± 12 ?g/dL, 0,60 ± 0,71 ?g/dL e 37 ± 42 ?g/g creatinina, respectivamente. No grupo não-exposto, os valores foram de 1,2 ± 1,2 ?g/dL, 0,048 ± 0,053 ?g/dL e 0,52 ± 0,48 ?g/g creatinina, respectivamente (p < 0,0010). O grupo exposto também apresentou maiores concentrações de GSH e GPx e menores concentrações de CAT e 8-OHdG em comparação ao grupo não-exposto(p < 0,0010). Correlações Spearman e análises de regressão multivariadas apontaram para associações entre Pb-s, Pb-p e 8-OHdG urinária. Um dos polimorfismos em HFE (rs1799945) foi associado positivamente a Pb-p (? = 0,15; p = 0,050). Indivíduos carreadores do alelo polimórfico do SNP rs1800562, também em HFE, apresentaram aumento da atividade de GPx e diminuição da concentração sanguínea de GSH. A atividade de GPx ainda foi positivamente associada ao SNP rs2228570, em VDR, e a variação alélica A>G em GSTP1 (rs1695), foi correlacionada à diminuição da atividade de GST. Os resultados obtidos demonstram que diferentes polimorfismos podem influenciar a toxicocinética do Pb e as concentrações de biomarcadores de estresse oxidativo em indivíduos expostos cronicamente ao metal Lead (Pb) is a toxic metal found in the environment and widely used in several industry sectors, such as the manufacturing of Pb-acid batteries. It may cause a number of adverse effects to human health, such as gastrointestinal, renal, neurological and hematopoietic disorders and oxidative stress. Pb-induced toxicity is modulated by several proteins, enzymes and antioxidant systems and, thus, it is presumed that genetic variations may influence the toxicokinectics of the metal in the body. Therefore, the objective of this work was to evaluate the impact of polymorphisms (SNPs) in genes related to Pb toxicokinectics (ALAD, GPx1, GSR, GSS, GSTP1, HFE, SLC11A1, SLC11A2 and VDR) on the metal concentrations in blood (Pb-b), plasma (Pb-p) and urine (Pb-u) and also on biomarkers of the redox status, i.e., glutathione (GSH), catalase (CAT), glutathione-peroxidase (GPX), glutathione S-transferase (GST) and urinary 8-hydroxy-2\'-deoxyguanosine (8-OHdG). 236 workers from automotive battery factories and 40 individuals non-occupationally exposed to Pb were enrolled in the study. Pb concentrations in the three biomarkers were determined by inductively coupled plasma mass spectrometry (ICP-MS) and genotyping was performed using the TaqMan method through the Real-Time Polymerase Chain Reaction (PCR). Enzyme activity was assessed through spectrophotometry and 8-OHdG was quantified through liquid chromatography tandem-mass spectrometry (LC-MS/MS). Mean values ± standard deviations of Pb-b, Pb-p and Pb-u for the exposed group were 21 ± 12 ?g/dL, 0.60 ± 0.71 ?g/dL and 37 ± 42 ?g/g creatinine, respectively. For the unexposed group, the levels were of 1.2 ± 1.2 ?g/dL, 0.048 ± 0.053 ?g/dL and 0.52 ± 0.48 ?g/g creatinine, respectively (p < 0.0010). The exposed group also showed higher levels of GSH and GPx, and lower levels of CAT and 8-OHdG, when compared to the unexposed group (p < 0.0010). Spearman correlations and multivariate linear regressions showed associations between urinary 8-OHdG, Pb-b and Pb-p. One of the HFE polymorphisms (rs1799945) was positively associated to Pb-p (? = 0.15; p = 0.050). Carriers of the polymorphic allele for the HFE rs1800562 SNP showed an increase in the activity of GPx and a decrease of the blood levels of GSH. GPx activity was also positively associated to the SNP rs2228570, in VDR, and the A>G allelic variation on GSTP1 (rs1695) was correlated to a lowered GST activity. The results demonstrate that different polymorphisms may play a role on Pb toxicokinectics and on the levels of oxidative stress biomarkers in workers chronically exposed to the metal