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The comet assay technique has been considered to be more efficient in the biomonitoring of aquatic environments that the micronucleus and sister chromatid exchange techniques. The comet assay has b...

Plants popularly used as medicine have been seen as promising natural agents by the pharmaceutical industry. In the present study the action of Psidium guajava L. (Pg) and Achillea millefolium L. (Am) infusions on chromosomal aberration formation in human lymphocyte system in vitro was assessed, associating them with the alkylating agent mitomycin C (MMC) and the DNA repair inhibitor cytosine-b-arabin-furanoside (Ara-C). The cells were cultivated for 72 h and treated continuously with Pg and the Am infusions at dosages of 2.62 · 10 � 4 g and 3.5 · 10 � 4 g/ml culture medium, respectively. Treatments with MMC (0.30 lg/ml) or Ara-C (5 · 10 � 7 lg/ml) were administered after 48 h of cell culture. Each samples (five individual) were exposed to nine treatments (control with PBS; Pg; Am; MMC; MMC + Pg; MMC + Am; Ara-C; Ara-C + Pg; and Ara-C + Am) and 100 cells were analyzed per cell culture. The used doses of each infusion did not cause clastogenic effects significantly different to the negative control (control ¼ 1%; Pg ¼ 2.2%; Am ¼ 1.8%). Nevertheless, the aberrant cell frequency after MMC treatment was significantly increased by the Am infusion (MMC ¼ 32.4%; MMC + Pg ¼ 36.2%; MMC + Am ¼ 44%), especially when the chromatid break types number was scored (MMC ¼ 151; MMC + Pg ¼ 173; MMC + Am ¼ 249). Regarding DNA repair inhibition by Ara-C, the Pg infusion caused a significant reduction in aberrant cell frequency (Ara-C ¼ 15.8%; Ara-C + Pg ¼ 11%; Ara-C + Am ¼ 14.4%), only when the chromatid break types number was scored (Ara-C ¼ 63; Ara-C + Pg ¼ 40; Ara-C + Am ¼ 58). These results indicate that the plant infusions per se do not have clastogenic activity, but can influence the clastogenic action of MMC and Ara-C on DNA break induction, in vitro. � 2004 Elsevier Ltd. All rights reserved.

Aims: Chlorophyllin (CHLN) is a synthetic derivative of chlorophyll that possesses antimutagenic activity against several environmental contaminants. In the present study, CHLN was assayed for its capacity to prevent nuclear fragmentation (NF) in HEp-2 cells infected with poliovirus. Methods and Results: CHLN was assayed at concentrations of 0·5 and 2·5 μg ml−1, and NF was monitored using the comet assay and acridine orange staining. We demonstrated that CHLN reduced the percentage of NF in poliovirus-infected HEp-2 cells, when cells were treated with drug before infection or exposed continuously to drug. However, the highest degree of protection was achieved when the virus was exposed to CHLN before infection followed by protocol where infected cultures were continuously exposed to the drug after infection. Conclusions: It is suggested that CHLN primarily binds to the virus which inhibits cell penetration, thereby maintaining nuclear integrity. Significance and Impact of the Study: Considering that CHLN has several beneficial properties and no significant toxic effects in humans and animals, it would be an ideal candidate drug to test for antiviral activity.

Casearia sylvestris is common in tropical America growing wild in Brazil in the states of Amazonas and Sao Paulo. Its leaves are used in Brazilian folk medicine for several diseases. The present investigation was carried out to examine the genotoxic effects of a C. sylvestris crude ethanolic extract on Hepatoma Tissue Culture (HTC cells) of Rattus norvegicus and Chinese hamster V79 cells in culture, using the comet assay. For the genotoxic evaluation the cells were treated with three different concentrations (0.5, 1 and 2 mg/ml) of extract prepared from a 25 mg/ml aqueous solution. The positive control was cyclophosphamide for HTC cells and methyl methanesulfonate for V79 cells. The duration of the treatment was 2 h. The results showed that the extract of C. sylvestris presented no genotoxic effects and not modified effect inducing DNA damage by alkylating agents cyclophosphamide and methyl methanesulfonate in HTC and V 79 cells respectivelly.

Chlorophyllin (CHL), a salt derivative of chlorophyll, has been demonstrated to be a potent agent against the deleterious action of different classes of mutagens. However, this effect depends largely on the test system, dose and conditions in which CHL is employed. The aim of this study was to examine in Allium cepa the toxic, cytotoxic and genotoxic effects of CHL and its capacity to inhibit such effects induced by the mutagenic agent mitomycin-C (MMC), under conditions of pre-treatment, post-treatment and concomitant treatment. The findings for this system indicate that CHL by itself does have toxic, cytotoxic or genotoxic effects. In examining the protective effect of this compound, CHL was not shown to reduce the cytotoxic effect previously produced by MMC in the first 20 h of treatment, but recovery from this effect was seen after 40 h. Under the conditions employed, this compound displayed an antigenotoxic or DNA-protective effect only immediately after treatment (20 h), being ineffective with the majority of concentrations tested after termination of the treatment.

Genotoxicity studies on toxic metals and their organic compounds are very important, especially so in the investigation of the effects of these compounds on the aquatic environments where they tend to accumulate. The use of endemic aquatic organisms as biological sentinels has proved useful to environmental monitoring. We assessed the mutagenic potential of tributyltin (TBT) and inorganic lead (PbII) using samples of the fish Hoplias malabaricus (commonly called traíra) using the comet assay and the piscine micronucleus and chromosome aberration tests. Eighteen H. malabaricus were acclimatized in three individual aquariums, each containing six fish, six fish being exposed to 0.3 mg/g of body weight (bw) of TBT, six to 21 mg/g bw of PbII and six being used as controls. Exposure to TBT and PbII was achieved by feeding the fish every five days with Astyanax (a small fish that is part of the normal diet of H. malabaricus) which had been injected with solutions of TBT, PbII or with water (the control group). After two months the H. malabaricus were sacrificed and their peripheral blood collected and subjected to the comet and micronucleus assays, the chromosome aberration assay being conducted using kidney-tissue. Although the comet assay showed now mutagenic effects at the lead concentrations used but encountered results with TBT, the micronucleus and chromosome aberrations assays both indicated that TBT and PbII are potentially mutagenic (p < 0.01), the micronucleus assay showing morphological alterations of the nucleus.

The Agaricus blazei Murill (ABM) mushroom, known as the sun mushroom, is native to Brazil and has become known for its medicinal properties. This study examined the anticlastogenic effect of Agaricus blazei in Chinese hamster ovary cells, CHO-k1, by means of a chromosome aberration test using methyl methanesulphonate (MMS, 10(-4)M) as the DNA damage inducing agent. Two mushroom lines were used, ABM 99/26 and ABM 97/11, and the latter was used in the young (Y) and sporulating (S) developmental phases. The cells were treated for 12 h with MMS alone or combined with aqueous extracts of A. blazei at a final concentration of 0.15%, which were prepared at three different temperatures: (a) hot (60 degrees C), (b) room temperature (25 degrees C) and (c) chilled (4 degrees C). Mushroom extracts showed a marked anticlastogenic effect against DNA damage, as evidenced by a decrease in the number of cells with breaks, regardless of the line used, or the developmental stage or the temperature at which the extract was prepared. Generally, the extracts were more effective in reducing the isochromatid type breaks. The data obtained suggest that extracts of A. blazei mushroom are anticlastogenic under the conditions tested, mainly during the G1 and S stages of the cell cycle, where chromosome breaks of the isochromatid type are produced by the MMS agent.

Agaricus blazei Murill is a medicinal mushroom native to Brazil. The present work assessed the clastogenic and anticlastogenic potential of organic extracts (ethanol and chloroform/methanol) from the lineage AB97/11 in chinese hamster CHO-K(1) (wild type) and CHO-xrs5 (repair deficient) cells using the chromosome aberration (CA) and sister chromatid exchange (SCE) assays. In these experimental conditions were observed: (a) anticlastogenic effect at concentrations of 0.06 and 0.09% of the EtOH extract and at the 0.03 and 0.06% concentrations of the C/MetOH extract in CHO-K(1); (b) absence of protector effect on CHO-xrs5 cells; and (c) absence of protector effect in the SCE assay. These results indicate that organic extracts of A. blazei lineage AB97/11 present bio-antimutagenic type protective activity.

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:20:57Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:43:57Z : No. of bitstreams: 1 2-s2.0-0347031274.pdf: 91642 bytes, checksum: 64b7b9eb08c147447977ab507d4fd2d4 (MD5) Made available in DSpace on 2014-05-27T11:20:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2003-12-01 The comet assay has been described as an efficient tool for the detection of changes in the DNA molecule of cells exposed to contaminating agents in vivo and in vitro. The possible environmental contamination due to the persistence of chromium residues from tannery effluents was determined in the waters of the Córrego dos Bagres stream, Municipal district of Franca/SP, by the comet assay on CHO-K1 cells. Water samples were collected during the four seasons of the year 2001 at three distinct stations along the river. The data suggest that the comet test showed good sensitivity for the environmental monitoring of these waters and indicated that this test can be efficient for the determination of the quality of waters contaminated with effluents containing heavy metal residues such as chromium. Univ. Fed. do Espírito Santo Depto. de Cie. Biológicas, Av. Marechal Campus 1468, CEP: 29040-090, Vitória/ES Universidade Estadual de Londrina Departamento de Biologia Geral, Cx. Postal. 601, CEP: 86051-990, Londrina/PR Universidade Estadual Paulista-UNESP 1B-Campus de Rio Claro, Av.24-A, 1515, CEP: 13506-900, Rio Claro/SP Universidade Estadual Paulista-UNESP 1B-Campus de Rio Claro, Av.24-A, 1515, CEP: 13506-900, Rio Claro/SP

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:20:37Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:38:41Z : No. of bitstreams: 1 2-s2.0-0037363659.pdf: 86115 bytes, checksum: a7c662e2d1d3b5df2f0375a862f40295 (MD5) Made available in DSpace on 2014-05-27T11:20:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2003-03-01 Agaricus blazei Murill is a mushroom largely consumed due to its medicinal properties. Effects of aqueous extract from its lineage AB97/11 in 2 fruiting body development stages (closed and opened pileus) were evaluated on chinese hamster V79 cells using cytokinesis blocking micronucleus (CBMN) and comet assays. The cells were treated at 0.15% concentration of aqueous extract prepared at different temperatures: ice-cold (4°C), room temperature (21°C) and warm (60°C). The extracts were applied in mutagenicity and antimutagenicity protocols (simultaneous, pre-incubation and continuous). The results showed that the aqueous extracts of Agaricus blazei lineage AB97/11 obtained at the 3 temperatures and both development stages did not present mutagenic or antimutagenic effect in V79 cells either in CBMN or comet assay. Departamento de Biologia Geral Universidade Estadual de Londrina, Londrina, PR Depto. de Prod. Vegetal Faculdade de Cie. Agronomicas UNESP, Botucatu, SP Depto. de Prod. Vegetal Faculdade de Cie. Agronomicas UNESP, Botucatu, SP

Chlorophyllin (Chl), a cupric salt of the chlorophyll, was used at concentrations of 12.5, 25, 50μg/ml in culture medium (Chl 12.5, Chl25, Chl150, respectively), in the presence or absence of mitomycin-C MMC (220×10-6M), in V79 cell culture, to assess the antimutagenic effects in the micronucleus assay on binucleate cells. Chlorophyllin was used in association with MMC in simultaneous treatments, pre and post treatments and simultaneous treatments after chlorophyllin had been pre-incubated with MMC for 1h. The results showed that chlorophyllin per se did not induce micronucleus formation at any of the concentrations assessed. The simultaneous treatment reduced significantly the micronucleus frequency at concentrations of 12.5 and 25μg, in 37.93 and 35.63%, respectively. At pre and post treatments, all the concentrations produced significant reductions: 45.98 Chl12.5), 43.68 (Chl25) and 28.73% (Chl50) in the pre treatment and of 36.78% (Chl 12.5), 51.72% (Chl25) and 37.93% (Chl50) in the post treatment. The same was observed in the simultaneous treatment after pre-incubation, where reduction of 48.27% (Chl 12.5), 57.47% (Chl25) and 58.62% (Chl50) were observed. These results indicated that chlorophyllin was not mutagenic in the system used and pointed to significant antimutagenic activity of the chlorophyllin. The data obtained in the simultaneous treatments suggested desmutagenic action whereas the pre and post treatments suggested bioantimutagenic activity of chlorophyllin in V79 cells.

Based on the concentration of Malathion used in the field, we evaluated the genotoxic potential of low concentrations of this insecticide on meristematic and F1 cells of Allium cepa and on rat hepatoma tissue culture (HTC cells). In the A. cepa, chromosomal aberrations (CAs), micronuclei (MN), and mitotic index (MI) were evaluated by exposing the cells at 1.5, 0.75, 0.37, and 0.18mg/mL of Malathion for 24 and 48hr of exposure and 48hr of recovery time. The results showed that all concentrations were genotoxic to A. cepa cells. However, the analysis of the MI has showed non-relevant effects. Chromosomal bridges were the CA more frequently induced, indicating the clastogenic action of Malathion. After the recovery period, the higher concentrations continued to induce genotoxic effects, unlike the observed for the lowest concentrations tested. In HTC cells, the genotoxicity of Malathion was evaluated by the MN test and the comet assay by exposing the cells at 0.09, 0.009, and 0.0009mg/5mL culture medium, for 24hr of exposure. In the comet assay, all the concentrations induced genotoxicity in the HTC cells. In the MN test, no significant induction of MN was observed. The genotoxicity induced by the low concentrations of Malathion presented in this work highlights the importance of studying the effects of low concentrations of this pesticide and demonstrates the efficiency of these two test systems for the detection of genetic damage promoted by Malathion.

We evaluated the effects of glutamine on clastogenic and genotoxic damage prevention caused by the administration of cisplatin. Forty Swiss mice were divided into 8 experimental groups: G1 and G2, which were control groups; G3, G4, and G5, which were administered [2 doses of glutamine (orally)] separated by a 24-h period (150, 300, and 600 mg/kg, respectively), and a dose of phosphate-buffered saline by intraperitoneal injection; G6, G7, and G8, which were treated in the same manner as the previous groups, but received cisplatin rather than phosphate-buffered saline. The antimutagenicity groups showed damage reduction percentages of 79.05, 80.00, and 94.27% at the time point T1, 53.18, 67.05, and 64.74 at time point T2 for the 150, 300, and 600 mg/kg doses of glutamine, respectively. Antigenotoxic activity was evident for all 3 doses with damage reduction percentages of 115.05, 119.06, and 114.38 for the doses of glutamine of 150, 300, and 600 mg/ kg, respectively. These results suggest that further studies are needed to confirm the clastogenic activity of glutamine. However, our results may lead to rational strategies for supplementation of this antioxidant as an adjuvant in cancer treatment or for preventing genomic lesions.

Fluoxetine, commonly known as Prozac, is the first representative of the so-called new generation of antidepressants that promise efficacy, with few side effects, against deep depression, nervous bulimia, and anxiety. As there is a growing number of people suffering from anxiety and depression; consequently, the use of fluoxetine is also increasing. Verifying absence of drug effects such as cytotoxicity or mutagenicity is of great importance. Certain vitamins, such as vitamin A (retinol, retinoids) and vitamin C (ascorbic acid) protect and are extremely active against mutagens. We evaluated the cytotoxic and mutagenic activity of fluoxetine, with and without concomitant administration of vitamin A or C, in Allium cepa meristem cells and Wistar rat bone marrow cells. The A. cepa meristem cells showed fluoxetine cytotoxicity; concomitant treatment with vitamin A or C proved non-protective. Treatment of Wistar rats with fluoxetine intraperitoneally or via gavage did not affect cell division or cause clastogenic effects. Vitamin A and C did not affect the cytotoxicity or mutagenicity of fluoxetine in the rat cells.

Made available in DSpace on 2015-03-18T15:56:26Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-01-01Bitstream added on 2015-03-18T16:28:21Z : No. of bitstreams: 1 WOS000340383600011.pdf: 713993 bytes, checksum: fe60ab6c90e2398831cafbe641230727 (MD5) FUNDECT Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) This study evaluated the mutagenicity and antimutagenicity of inulin in a chromosomal aberration assay in cultures of the meristematic cells of Allium cepa. The treatments evaluated were as follows: negative control - seed germination in distilled water; positive control - aqueous solution of methyl methanesulfonate (10 mu g/mL MMS); mutagenicity - aqueous solutions of inulin (0.015, 0.15, and 1.50 mu g/mL); and antimutagenicity - associations between MMS and the different inulin concentrations. The antimutagenicity protocols established were pretreatment, simultaneous simple, simultaneous with pre-incubation, and post-treatment. The damage reduction percentage (DR%) was 43.56, 27.77, and 55.92% for the pre-treatment; -31.11, 18.51, and 7.03% for the simultaneous simple; 30.43, 19.12, and 21.11% for the simultaneous with pre-incubation; and 64.07, 42.96, and 53.70% for the post-treatment. The results indicated that the most effective treatment for inhibiting damages caused by MMS was the post-treatment, which was followed by the pretreatment, suggesting activity by bioantimutagenesis and desmutagenesis. The Allium cepa assay was demonstrated to be a good screening test for this type of activity because it is easy to perform, has a low cost, and shows DR% that is comparable to that reported studies that evaluated the prevention of DNA damage in mammals by inulin. Univ Fed Mato Grosso do Sul, Nucleo Hosp Univ, Ctr Estudos Celulas Tronco Terapia Celular & Gene, Campo Grande, MS, Brazil Univ Fed Mato Grosso do Sul, Rede Pro Ctr Oeste, Programa Doutorado Biotecnol & Biodiversidade, Campo Grande, MS, Brazil Univ Fed Mato Grosso do Sul, Fac Med Dr Helio Mandetta, Regiao Ctr Oeste, Programa Pos Grad Saude Desenvolvimento, Campo Grande, MS, Brazil Univ Estadual Paulista, Inst Biociencias Rio Claro, Programa Pos Grad Biol Celular & Mol, Rio Claro, SP, Brazil Univ Fed Mato Grosso do Sul, Ctr Ciencias Biol & Saude, Programa Mestrado Farmacia, Campo Grande, MS, Brazil Univ Fed Mato Grosso do Sul, Ctr Ciencias Biol & Saude, Campo Grande, MS, Brazil Univ Estadual Londrina, Ctr Ciencias Biol, Dept Biol, Londrina, PR, Brazil Univ Estadual Paulista, Inst Biociencias Rio Claro, Programa Pos Grad Biol Celular & Mol, Rio Claro, SP, Brazil FUNDECT5/2011 FUNDECT23/200.702/2012 FUNDECT0207/12 FUNDECT08/2009 FUNDECT15411.285.865.22102009 CNPq: 06/2011 CNPq: PRONEM

Chlorophyll and its derivatives are examples of plant compounds (purified and/or extracted) which appear to protect DNA from damage caused by chemical or physical agents, although some studies have identified clastogenic activity of these compounds. This study was carried out to assess the genotoxic activity of chlorophyll-a (Chl-a), -b (Chl-b) and chlorophyllin (Chl) and their antigenotoxic activity against the DNA damage induced by methyl methanesulphonate (MMS) under conditions of simultaneous, pre-, post-treatment, and simultaneous treatment after pre-incubation of the chemical with MMS. The micronucleus (MN) test was used in binucleated cells (induced by cytochalasin-B) of a mammalian cell line (V79). The three concentrations of Chl-a, Chl-b or Chl (0.1375, 0.275, 0.55microM) were not genotoxic and the genotoxic action of MMS (400microM) decreased (74-117%) under all treatment conditions. The results showed that there was no significant difference among the treatment types, the concentration or the nature of chlorophyll used. The data obtained suggest that Chl-a, Chl-b and Chl when associated with the DNA damaging agent, MMS, may protect the DNA by desgenotoxic action and/or by bio-antigenotoxic mechanisms, with the similar efficiency.

Agaricus blazei Murrill, a native mushroom in Brazil, has been widely consumed in different parts of the world due to its medicinal power. Its anticarcinogenic activity has been shown in experimental animals, and antimutagenic activity has been demonstrated only in Salmonella. In this work, the mutagenic and antimutagenic activities of mushroom teas of strains AB96/07, AB96/09 and AB97/11 were evaluated in Chinese hamster V79 cells, using the comet assay and the micronucleus test. The cells were treated with three different concentrations (0.05, 0.1 and 0.15) of teas prepared from a 2.5% aqueous solution, under three different temperatures: (1) room (20-25 degrees C); (2) ice-cold (2-8 degrees C); and (3) warm (60 degrees C). The teas were applied in co-, pre- and post-treatments in combination with the mutagen methyl methanesulfonate (MMS; 1.6x10(-4) and 4x10(-4)M). The duration of the treatment was 1h in the comet assay and 2h in the micronucleus test. The results showed that the mushroom was not mutagenic itself. Nevertheless, the mushroom is an efficient antimutagen against the induction of micronuclei by MMS in all concentrations and preparations tested. The observed reductions in the frequencies of micronuclei ranged from 61.5 (room temperature 0.1% tea in post-treatment) to 110.3% (co-treatment with warm and ice-cold 0.15% tea). In the comet assay, the antimutagenic activity was detected only when the cells were pre-treated with the following teas: warm 0.1 and 0.15%, room temperature 0.05% and ice-cold 0.1%. The results indicate that the mushroom A. blazei extracts are antimutagenic when tested in V79 cells.

The essential oil composition obtained from the leaves of Casearia sylvestris has been investigated by GC and GC/MS. Thirty-seven compounds were identified in the oil. The major constituents of which were β-caryophyllene (27.5%) and bicyclogermacrene (24.2%). The clastogenic and anticlastogenic effect of the oil was tested by chromosome aberration in cells of tissue hepatoma of Rattus novergicus. The three different concentrations of C. sylvestris oil showed clastogenic effects. However, in the tests of anticlastogenicity, the same three concentrations showed protective activity when associated with ethyl methanesulfonate (EMS).

Several studies have demonstrated that a balanced diet can contribute to better human health. For this reason, soy-based food and pure isoflavones (pills) are one of the most consumed. The association of this consumption and lower risks of chronic diseases and cancer is well established for the Asian population and has been attracting thw attention of people worldwide, especially women at menopause who seek to alleviate the symptoms associated with the lack of estrogen. Despite positive epidemiological data, concerns still exist because of conflicting results found in scientific literature with relation to the role of isoflavones in breast and hormone-related cancers. The aim of our study was to investigate the cytotoxicity, induction of apoptosis, and changes in apoptosis-related genes of maximal physiological serum levels of the isoflavone genistein (Gen) in MCF-7 tumoral cells and in HB4a non-tumoral cells. In addition, induction of cell cycle arrest was also investigated. Only supraphysiological levels of Gen (50 and 100 μM) were cytotoxic to these cell lines. Concentrations of 10 and 25 μM did not induce apoptosis and significant changes in expression of the studied genes. Positive results were found only in cell cycle analysis: G0/G1 delay of MCF-7 cells in both concentrations of Gen and at 25 μM in HB4a cells. It is the first study investigating effects of Gen in the HB4a cell line. Thus, despite the lack of apoptosis induction (generally found with high concentrations), Gen at physiologically relevant serum levels still exerts chemopreventive effects through the modulation of cell cycle.

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:30:02Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:32:46Z : No. of bitstreams: 1 2-s2.0-84880814650.pdf: 452677 bytes, checksum: 84b67da951d5cf92c9d1fc75fda11d2f (MD5) Made available in DSpace on 2014-05-27T11:30:02Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-07-24 The malaria treatment recommended by the World Health Organization involves medicines derived from artemisinin, an active compound extracted from the plant Artemisia annua, and some of its derivatives, such as artesunate. Considering the lack of data regarding the genotoxic effects of these compounds in human cells, the objective of this study was to evaluate the cytotoxicity and genotoxicity, and expressions of the CASP3 and SOD1 genes in a cultured human hepatocellular liver carcinoma cell line (HepG2 cells) treated with artemisinin and artesunate. We tested concentrations of 2.5, 5, 7.5, 10, and 20 μg/mL of both substances with a resazurin cytotoxicity assay, and the concentrations used in the genotoxicity experiments (2.5, 5, and 10 μg/mL) and gene expression analysis (5 mg/mL) were determined. The results of the comet assay in cells treated with artemisinin and artesunate showed a significant dosedependent increase (P < 0.001) in the number of cells with DNA damage at all concentrations tested. However, the gene expression analysis revealed no significant change in expression of CASP3 or SOD1. Our data showed that although artemisinin and artesunate exhibited genotoxic effects in cultured HepG2 cells, they did not significantly alter expression of the CASP3 and SOD1 genes at the doses tested. ©FUNPEC-RP. Instituto de Biociências Universidade Estadual Paulista, Botucatu, SP Instituto de Biociências Universidade Estadual Paulista, Rio Claro, SP Laboratório de Genética Toxicológica Universidade Estadual de Londrina, Londrina, PR Departamento de Ciências Exatas e da Terra Universidade Federal de São Paulo, Diadema, SP Departamento de Fonoaudiologia Universidade Estadual Paulista, Marília, SP Instituto de Biociências Universidade Estadual Paulista, Botucatu, SP Instituto de Biociências Universidade Estadual Paulista, Rio Claro, SP Departamento de Fonoaudiologia Universidade Estadual Paulista, Marília, SP

Made available in DSpace on 2014-12-03T13:10:59Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-01-01Bitstream added on 2014-12-03T13:22:51Z : No. of bitstreams: 1 S1415-47572013005000028.pdf: 873406 bytes, checksum: c3cad0bf076103644fa73972b326b48b (MD5) Item merged in doublecheck by Felipe Arakaki (arakaki@reitoria.unesp.br) on 2015-12-11T19:24:41Z Item was identical to item(s): 108691, 111804 at handle(s): http://hdl.handle.net/11449/109608, http://hdl.handle.net/11449/112704 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundacao Araucaria Ample evidence suggests that cancer is triggered by mutagenic damage and diets or supplements capable of reducing such incidences can be related to the prevention of neoplasy development or to an improvement in life quality of patients who undergo chemotherapy. This research aimed to evaluate the antimutagenic and antigenotoxic activity of beta-glucan. We set up 8 experimental groups: control (Group 1), cyclophosphamide (Group 2), Groups 3-5 to assess the effect of beta-glucan administration, and Groups 6-8 to evaluate the association between cyclophosphamide and beta-glucan. The intraperitonial concentrations of beta-glucan used were 100, 150 and 200 mg/kg. Micronucleus and comet assays showed that within the first week of treatment beta-glucan presented a damage reduction rate between 100-62.04% and 94.34-59.52% for mutagenic and genotoxic damages, respectively. This activity decreased as the treatment was extended. During the sixth week of treatment antimutagenicity rates were reduced to 59.51-39.83% and antigenotoxicity was not effective. This leads to the conclusion that the efficacy of beta-glucan in preventing DNA damage is limited when treatment is extended, and that its use as a chemotherapeutic adjuvant need to be better clarified. Univ Fed Mato Grosso do Sul, Nucleo Hosp Univ, Ctr Estudos Celula Tronco Terapia Celular & Genet, BR-79070900 Campo Grande, MS, Brazil Univ Fed Mato Grosso do Sul, Fac Med Dr Helio Mandetta, Programa Posgrad Saude Desenvolvimento Regiao Ctr, BR-79070900 Campo Grande, MS, Brazil Univ Fed Mato Grosso do Sul, Ctr Ciencias Biol & Saude, Programa Mestrado Farm, BR-79070900 Campo Grande, MS, Brazil Univ Estadual Londrina, Dept Biol Geral, Londrina, PR, Brazil Univ Estadual Londrina, Lab Tecnol Alimentos & Medicamentos, Londrina, PR, Brazil Univ Estadual Paulista, Inst Biociencias, Programa Posgrad Biol Celular & Mol, Rio Claro, SP, Brazil Univ Estadual Paulista, Inst Biociencias, Programa Posgrad Biol Celular & Mol, Rio Claro, SP, Brazil

Background St. John’s wort (Hypericum perforatum L.) is an herbaceous plant that is native to Europe, West Asia and North Africa and that is recognized and used worldwide for the treatment of mild and moderate depression. It also has been shown to be therapeutic for the treatment of burns, bruises and swelling and can be used for its wound healing, antiviral, antimicrobial, antioxidant, analgesic, hepato-protective and anxiolytic properties. The aim of this study was to evaluate the potential cytotoxic, mutagenic and antimutagenic action of H. Perforatum. Methods Meristematic cells were used as the test system for Allium cepa L., and bone marrow cells from Rattus norvegicus, ex vivo, were used to calculate the mitotic index and the percentage of chromosomal aberration. Statistical analysis was performed using the chi-square test. Results This medicinal plant had no cytotoxic potential in the vegetal test system evaluated. In the animal test system, none of the acute treatments, including intraperitoneal gavage and subchronic gavage, were cytotoxic or mutagenic. Moreover, this plant presented antimutagenic activity against the clastogenic action of cyclophosphamide, as confirmed in pre-treatment (76% reduction in damage), simultaneous treatment (95%) and post-treatment (97%). Conclusions Thus, the results of this study suggest that the administration of H. perforatum, especially by gavage similar to oral consumption used by humans, is safe and with beneficial antimutagenic potential.

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:29:01Z No. of bitstreams: 0 Made available in DSpace on 2014-05-27T11:29:01Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-05-01 (-)-Cubebin is a lignan extracted from the seeds of the pepper Piper cubeba, a commonly eaten spice with beneficial properties, including trypanocidal, anti-inflammatory, analgesic, anti-proliferative and leishmanicidal activities. Because of its therapeutic potential, we investigated the effects of (-)-cubebin on the cytotoxicity, cell proliferation kinetics, mutagenicity and expression of p38 MAP kinase and glutathione S-transferase a2 (GSTa2) using real-time RT-PCR in Rattus norvegicus hepatoma cells. We found that 280 μM (-)-cubebin was cytotoxic after 24, 48 and 72. h of exposure, but not mutagenic at 0.28 μM, 2.8 μM and 28 μM after 26. h. Similarly, exposure to 0.28 μM, 2.8 μM and 28 μM (-)-cubebin for 24, 48, 72 and 96. h did not alter the cell proliferation kinetics. Cells exposed to 28 μM (-)-cubebin for 24. h did not exhibit changes in p38 MAP kinase and GSTa2 expression, indicating that cellular changes were not induced by extracellular stimuli and that (-)-cubebin is likely not metabolized via this pathway. Our results suggest that high levels of (-)-cubebin should be consumed with caution due to the cytotoxic effect observed at the highest concentration. However, at lower concentrations, no cytotoxic, mutagenic or proliferative effects were observed, providing further evidence of the safety of consuming (-)-cubebin. © 2013 Elsevier Inc. Departamento de Biologia Geral Universidade Estadual de Londrina (UEL), Londrina (PR) Instituto de Biociências Universidade Estadual Paulista - UNESP, Rio Claro, São Paulo Departamento de Fonoaudiologia Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Marília, São Paulo Instituto de Biociências Universidade Estadual Paulista - UNESP, Rio Claro, São Paulo Departamento de Fonoaudiologia Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Marília, São Paulo

Studies show that soy imparts many favorable properties in the human body, including the prevention of chronic diseases such as osteoporosis, heart disease, cancer, and diabetes. Soy is rich in isoflavones, and it is a candidate for the chemoprevention of diseases owing to its low toxicity. In this study, a soy phytoestrogen (with high levels of the isoflavones genistin and daidzein) was tested in mice to investigate its mutagenicity and genotoxicity using micronucleus and comet assays of mouse peripheral blood. Phytoestrogen (0.083, 0.83 and 8.3 mg/kg body weight) was evaluated with and without the chemotherapeutic agent cyclophosphamide. For the micronucleus assay, blood was collected before treatment and after 24 and 48 h. For the comet assay, blood was collected only after 24 h. Phytoestrogen was not mutagenic and reduced cyclophosphamide-induced DNA damage. The results from the comet assay revealed a reduction of DNA damage; however, phytoestrogen did induce genotoxic damage during the 24-h treatment. This genotoxic damage could have been repaired and was therefore not identified in the micronucleus assay, which detects mutations. The results suggested that the reduction of DNA damage observed in associated treatments could also reduce the side effects of chemotherapy. Moreover, they suggested that phytoestrogen might be a candidate of interest for the chemoprevention of cancer because it protects against DNA damage.

The polysaccharide β-glucan has biological properties that stimulate the immune system and can prevent chronic pathologies, including cancer. It has been shown to prevent damage to DNA caused by the chemical and physical agents to which humans are exposed. However, the mechanism of β-glucan remains poorly understood. The objective of the present study was to verify the protective effect of β-glucan on the expression of the genes ERCC5 (involved in excision repair of DNA damage), CASP9 (involved in apoptosis), and CYP1A1 (involved in the metabolism of xenobiotics) using real-time polymerase chain reaction and perform metabolic profile measurements on the HepG2 cells. Cells were exposed to only benzo[a]pyrene (B[a]P), β-glucan, or a combination of B[a]P with β-glucan. The results demonstrated that 50 µg/mL β-glucan significantly repressed the expression of the ERCC5 gene when compared with the untreated control cells in these conditions. No change was found in the CASP9 transcript level. However, the CYP1A1 gene expression was also induced by HepG2 cells exposed to B[a]P only or in association with β-glucan, showing its effective protector against damage caused by B[a]P, while HepG2 cells exposed to only β-glucan did not show CYP1A1 modulation. The metabolic profiles showed moderate bioenergetic metabolism with an increase in the metabolites involved in bioenergetic metabolism (alanine, glutamate, creatine and phosphocholine) in cells treated with β-glucan and to a lesser extent treated with B[a]P. Thus, these results demonstrate that the chemopreventive activity of β-glucan may modulate bioenergetic metabolism and gene expression.

Made available in DSpace on 2014-12-03T13:11:00Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-01-01Bitstream added on 2014-12-03T13:22:50Z : No. of bitstreams: 1 WOS000331608000193.pdf: 317025 bytes, checksum: aee30c8baf1d6d815e4ee039e14ea833 (MD5) Pro-Reitoria de Pesquisa e Pos-Graduacao - Centro Universitario Filadelfia (UniFil) Fundacao Araucaria: Apoio ao Desenvolvimento Cientifico e Tecnologico do Parana Fundacao de Apoio ao Desenvolvimento do Ensino, Ciencia e Tecnologia (FUNDECT) of the State of Mato Grosso do Sul Cisplatin is an effective antineoplastic drug. However, it provokes considerable collateral effects, including genotoxic and clastogenic activity. It has been reported that a diet rich in glutamine can help inhibit such collateral effects. We evaluated this activity in 40 Swiss mice, distributed into eight experimental groups: G1 - Control group (PBS 0.1 mL/10g body weight); G2 - cisplatin group (cisplatin 6 mg/kg intraperitoneally); G3, G4, G5 - glutamine groups (glutamine at 150, 300, and 600 mg/kg, respectively; orally); G6, G7, G8 - Pre-treatment groups (glutamine at 150, 300, and 600 mg/kg, respectively; orally and cisplatin 6 mg/kg intraperitonially). For the micronucleus assay, samples of blood were collected (before the first use of the drugs at T0, then 24 (T1) and 48 (T2) hours after the first administration). For the comet assay, blood samples were collected only at T2. The damage reduction percentages for the micronucleus assay were 90.0, 47.3, and 37.3% at T1 and 46.0, 38.6, and 34.7% at T2, for G6, G7, and G8 groups, respectively. For the comet assay, the damage reduction percentages were 113.0, 117.4, and 115.0% for G6, G7, and G8, respectively. We conclude that glutamine is able to prevent genotoxic and clastogenic damages caused by cisplatin. Univ Fed Mato Grosso do Sul, Nucleo Hosp Univ, Ctr Estudos Celulas Tronco Terapia Celular & Gene, Campo Grande, MS, Brazil Univ Fed Mato Grosso do Sul, Fac Med Dr Helio Mandetta, Programa Posgrad Saude Desenvolvimento Regiao Ctr, Campo Grande, MS, Brazil Univ Fed Mato Grosso do Sul, Ctr Ciencias Biol & Saude, Programa Mestrado Farm, Campo Grande, MS, Brazil Ctr Univ Filadelfia, Ctr Estudo Nutr & Genet Toxicol CENUGEN, Londrina, PR, Brazil Univ Fed Mato Grosso do Sul, Ctr Ciencias Biol & Saude, Campo Grande, MS, Brazil Univ Estadual Paulista, Programa Posgrad Biol Celular & Mol, Inst Biociencias, Rio Claro, SP, Brazil Univ Estadual Londrina, Dept Biol Geral, Londrina, PR, Brazil Univ Estadual Paulista, Programa Posgrad Biol Celular & Mol, Inst Biociencias, Rio Claro, SP, Brazil

Estudos epidemiologicos mostram que a ingestao de alimentos ricos em isoflavonas (fitoestrogenos), como a soja, confere protecao contra varios tipos de câncer, o que aumenta o interesse cientifico e popular sobre esses compostos. No presente estudo, os fitoestrogenos de extrato de soja foram testados quanto aos efeitos genotoxicos e modulador de benzo [a] pireno e bleomicina. Dois fitoestrogenios foram avaliados in vitro, o fitoestrogenos “A” foi fornecido pela Embrapa-Soja, Londrina - PR, e o fitoestrogenos “B” foi comprado em uma farmacia de manipulacao local. Os metodos utilizados foram o teste do Cometa (genotoxicidade e antigenotoxicidade) e teste do Micronucleo com Bloqueio Citocinese (mutagenicidade) em celulas de hepatoma de rato (HTC celulares). As isoflavonas foram testadas em tres concentracoes pre-estabelecidas pelo ensaio de citotoxidade MTT. Ambos os extratos de isoflavonas nao mostraram efeitos genotoxicos no ensaio do cometa, mas mostraram inducao de micronucleo. Na avaliacao dos fitoestrogenios para um efeito modulador, ambos os extratos fitoestrogenios mostraram efeito antigenotoxico no ensaio do cometa.

Nicorandil is a nitric oxide (NO) donor used in the treatment of angina symptoms. It has also been reported to protect cells and affect the proliferation and death of cells in some tissues. The molecules that interfere with these processes can cause dysfunction in healthy tissues but can also assist in the therapy of some disorders. In this study we examined the effect of nicorandil and of the molecular precursor that does not have the NO radical (N-(beta-hydroxyethyl) nicotinamide) on the cell proliferation and death of human renal carcinoma cells (786-O) under normal oxygenation conditions. The molecular precursor was used in order to analyze the effects independents of NO. In the cytotoxicity test, nicorandil was shown to be cytotoxic at very high concentrations and it was more cytotoxic than its precursor (cytotoxic at concentrations of 2,000 and 3,000 μg/mL, respectively). We propose that the lower cytotoxicity of the precursor is due to the absence of the NO radical. In this study, the cells exposed to nicorandil showed neither statistically significant changes in cell proliferation nor increases in apoptosis or genotoxicity. The precursor generated similar results to those of nicorandil. We conclude that nicorandil causes no changes in the proliferation or apoptosis of the cell 786-O in normal oxygenation conditions. Moreover, the lack of NO radical in the precursor molecule did not show a different result, except in the cell cytotoxicity.

Isoflavones are phenolic compounds widely distributed in plants and found in a high percentage in soybeans. They have important biological properties and are regarded as potential chemopreventive agents. The aim of this study was to verify the preventive effect of two soy isoflavones (genistein and daidzein) by a micronucleus assay, analysis of GST activity, and real-time RT-PCR analysis of GSTa2 gene expression. Mutagens of direct (doxorubicin) and indirect (2-aminoanthracene) DNA damage were used. Hepatoma cells (HTC) were treated with genistein or daidzein for 26 h at noncytotoxic concentrations; 10 μM when alone, and 0.1, 1.0 and 10 μM when combined with genotoxic agents. The micronucleus test demonstrated that both isoflavones alone had no genotoxic effect. Genistein showed antimutagenic effects at 10 μM with both direct and indirect DNA damage agents. On phase II enzyme regulation, the current study indicated an increase in total cytoplasmic GST activity in response to genistein and daidzein at 10 μM supplementation. However, the mRNA levels of GSTa2 isozymes were not differentially modulated by genistein or daidzein. The results point to an in vitro antimutagenic activity of genistein against direct and indirect DNA damage-induced mutagenicity.

β-glucan is an important polysaccharide due to its medicinal properties of stimulating the immune system and preventing chronic diseases such as cancer. The aim of the present study was to determine the anticlastogenic effect of β-glucan in cells exposed to ultraviolet radiation (UV). Chromosome aberration assay was performed in drug-metabolizing cells (HTC) and non drug-metabolizing cells (CHO-K1 and repair-deficient CHO-xrs5), using different treatment protocols. Continuous treatment (UV + β-glucan) was not effective in reducing the DNA damage only in CHO-xrs5 cells. However, the pre-treatment protocol (β-glucan before UV exposition) was effective in reducing DNA damage only in CHO-K1 cells. In post-treatment (β-glucan after UV exposition) did not show significative anticlastogenic effects, although there was a tendency toward prevention. The data suggest that β-glucan has more than one action mechanism, being capable of exerting desmutagenic as well as bio-antimutagenic action. The findings also suggest that the presence of the xenobiotic metabolizing system can reduce the chemopreventive capacity of β-glucan. Therefore, these results indicate that β-glucan from Saccharomyces cerevisiae can be used in the prevention and/or reduction of DNA damage.

Made available in DSpace on 2013-09-27T14:54:05Z (GMT). No. of bitstreams: 1 WOS000295804800062.pdf: 498298 bytes, checksum: a47df949c8c5eedd1981ae1e1f80861d (MD5) Previous issue date: 2011-01-01 Made available in DSpace on 2013-09-30T18:15:27Z (GMT). No. of bitstreams: 1 WOS000295804800062.pdf: 498298 bytes, checksum: a47df949c8c5eedd1981ae1e1f80861d (MD5) Previous issue date: 2011-01-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:31:45Z No. of bitstreams: 1 WOS000295804800062.pdf: 498298 bytes, checksum: a47df949c8c5eedd1981ae1e1f80861d (MD5) Made available in DSpace on 2014-05-20T13:31:45Z (GMT). No. of bitstreams: 1 WOS000295804800062.pdf: 498298 bytes, checksum: a47df949c8c5eedd1981ae1e1f80861d (MD5) Previous issue date: 2011-01-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Phenols are a large and diverse class of compounds, many of which occur naturally in a variety of food plants; they exhibit a wide range of biological effects, including antibacterial, anti-inflammatory, antiallergic, hepatoprotective, antithrombotic, antiviral, anticarcinogenic, and vasodilatory actions. We examined the genotoxic and clastogenic potential of three phenolic compounds: caffeic, cinnamic and ferulic acids, using the comet and micronucleus assays in vitro. Drug-metabolizing rat hepatoma tissue cells (HTCs) were used. Three different concentrations (50, 500 and 1500 mu M) of these phenolic acids were tested on the HTCs for 24 h. The caffeic, cinnamic and ferulic acids were not genotoxic by the comet assay (P > 0.05). However, the micronucleus test showed an increase in the frequency of micronucleated cells for the three compounds, indicating that these substances have clastogenic effects in HTC. Univ Estadual Paulista, Dept Fonoaudiol, Fac Filosofia & Ciencias, UNESP, Marilia, SP, Brazil Universidade Estadual de Londrina (UEL), Dept Biol Geral, Londrina, PR, Brazil Univ Vale Itajai, Nucleo Invest Quim Farmaceut, Itajai, SC, Brazil Univ Estadual Paulista, Dept Fonoaudiol, Fac Filosofia & Ciencias, UNESP, Marilia, SP, Brazil CNPq: 306544/2006-7 FAPESP: 06/57514-2

Intestinal cancers are correlated with diet. Thus, determining and understanding nutrient-genome interactions is important. The present work assessed the action of the oligoelement selenium on cell proliferation, cytotoxicity, and in situ apoptosis induction and on the expression CASP9, BCL-XL and APC genes in intestinal adenocarcinoma cells (HT29). HT29 cells were cultured and treated with selenium at concentrations of 5, 50 and 500ng/mL with or without the damage-inducing agent doxorubicin. These cells were then evaluated for cytotoxicity (MTT), cell proliferation and in situ apoptosis induction. To evaluate gene expression, only the cells treated with 500ng/mL of selenium were used. RNA was extracted from these cells, and the expressions of CASP9, BCL-XL and APC were analyzed by the RT-PCR method. The GAPDH gene was used as a reference gene. The MTT assay showed that selenium was not cytotoxic at any of the concentrations tested. The cell proliferation assay showed that selenium did not interfere with cell proliferation at the three concentrations tested. In contrast, when the three concentrations were combined with doxorubicin, a significant decrease in the proliferation rate was observed. The apoptosis rate was significantly increased in the selenium (500ng/mL) and doxorubicin group. CASP9 expression was increased and BCL-XL expression decreased in the selenium (500ng/mL) and doxorubicin group. APC was significantly increased in the selenium group alone. These results show that selenium increases apoptosis, especially when it is associated with a damage-inducing agent. Also, selenium has an important role in the expression of the APC gene, which is related to cell cycle regulation.

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:25:31Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:31:08Z : No. of bitstreams: 1 2-s2.0-79952696151.pdf: 296189 bytes, checksum: b80c444d35169a4bf48b8f5e92f09242 (MD5) Made available in DSpace on 2014-05-27T11:25:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-04-01 The development of various types of cancer results from the interaction among endogenous, environmental and hormonal factors, where the most notable of these factors is diet. The aim of the present study was to determine the antigenotoxic, anticarcinogenic, phagocytic and immunomodulatory activities of Agaricus blazei. The test antigenotoxicity (Comet Assay) and anticarcinogenic (Test of Aberrant Crypt Foci) assess changes in DNA and/or intestinal mucosa that correlate to cancer development. Tests of phagocytosis in the spleen and differential count in blood cells allow the inference of modulation of the immune system as well as to propose a way of eliminating cells with DNA damage. Supplementation with the mushroom was carried out under pre-treatment, simultaneous treatment, post-treatment and pre-treatment. +. continuous conditions. Statistical analysis demonstrated that the mushroom did not have genotoxic activity but showed antigenotoxic activity. Supplementation caused an increase in the number of monocytes and in phagocytic activity, suggesting that supplementation increases a proliferation of monocytes, consequently increasing phagocytic capacity especially in the groups pre-treatment, simultaneous and pre-treatment. +. continuous. The data suggest that A. blazei could act as a functional food capable of promoting immunomodulation which can account for the destruction of cells with DNA alterations that correlate with the development of cancer, since this mushroom was demonstrated to have a preventive effect against pre-neoplastic colorectal lesions evaluated by the aberrant crypt foci assay. According to these results and the literature, it is believed that supplementation with A. blazei can be an efficient method for the prevention of cancer as well as possibly being an important coadjuvant treatment in chemotherapy. © 2011 Elsevier Inc. Centro de Estudos em Nutrição e Genética Toxicológica - CENUGEN Departamento de Nutrição Centro Universitário Filadélfia, Londrina - PR Centro de Estudos em Nutrição e Genética Toxicológica - CENUGEN Departamento de Biomedicina Centro Universitário Filadélfia, Londrina - PR Laboratório de Genética Toxicológica Centro de Ciências Biológicas Departamento de Biologia Geral, Universidade Estadual de Londrina, Londrina - PR Instituto de Biociências de Rio Claro Departamento de Biologia Universidade Estadual Paulista Júlio de Mesquita Filho, Rio Claro, SP Centro de Ciências da Saúde Departamento de Ciências Farmacêuticas Universidade Estadual de Londrina, Londrina - PR Coordenadoria de Educação Aberta e a Distância CED/RTR Universidade Federal de Mato Grosso do Sul UFMS Instituto de Biociências de Rio Claro Departamento de Biologia Universidade Estadual Paulista Júlio de Mesquita Filho, Rio Claro, SP

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:57:48Z No. of bitstreams: 1 S0102-695X2010000300009.pdf: 735122 bytes, checksum: 5ba96c2951bbeb08c5ca2d4642e6f29c (MD5) Made available in DSpace on 2013-08-22T18:57:48Z (GMT). No. of bitstreams: 1 S0102-695X2010000300009.pdf: 735122 bytes, checksum: 5ba96c2951bbeb08c5ca2d4642e6f29c (MD5) Previous issue date: 2010-07-01 Made available in DSpace on 2013-09-30T19:52:52Z (GMT). No. of bitstreams: 2 S0102-695X2010000300009.pdf: 735122 bytes, checksum: 5ba96c2951bbeb08c5ca2d4642e6f29c (MD5) S0102-695X2010000300009.pdf.txt: 44432 bytes, checksum: a114b59500f3116551d9dbf63ae9499a (MD5) Previous issue date: 2010-07-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T15:13:45Z No. of bitstreams: 2 S0102-695X2010000300009.pdf: 735122 bytes, checksum: 5ba96c2951bbeb08c5ca2d4642e6f29c (MD5) S0102-695X2010000300009.pdf.txt: 44432 bytes, checksum: a114b59500f3116551d9dbf63ae9499a (MD5) Made available in DSpace on 2014-05-20T15:13:45Z (GMT). No. of bitstreams: 2 S0102-695X2010000300009.pdf: 735122 bytes, checksum: 5ba96c2951bbeb08c5ca2d4642e6f29c (MD5) S0102-695X2010000300009.pdf.txt: 44432 bytes, checksum: a114b59500f3116551d9dbf63ae9499a (MD5) Previous issue date: 2010-07-01 A presente pesquisa avaliou a ação mutagênica e antimutagênica de um biopolímero de glucose extraído da Agrobacterium radiobacter (Biopolímero de Agrobacterium radiobacter). O experimento foi realizado com camundongos Swiss machos divididos em oito grupos. O tratamento com o biopolímero foi realizado por gavage em dose única concomitante a uma dose de solução tampão fosfato nos grupos de avaliação da mutagenicidade, ou ao agente indutor de danos no DNA, ciclofosfamida, na concentração de 50 mg/kg (peso corpóreo - p.c.), nos grupos de avaliação da antimutagenicidade. Utilizou-se o teste de micronúcleo em sangue periférico e a coleta de sangue foi realizada 24 e 48 h após a aplicação das substâncias-teste. A análise estatística demonstrou que o biopolímero não possui atividade mutagênica e que é efetivo em prevenir danos no DNA. As porcentagens de redução de danos nos grupos de antimutagenicidade foram de 83,9%, 89,1% e 103,1% em 24 h e 101,24%, 98,14% e 120,64% em 48 h para as doses de 75, 150 e 300mg/kg (p.c.), respectivamente. A alta porcentagem de redução de danos associada à ausência de efeitos mutagênicos indica, além da atividade quimioprotetora, a possibilidade do biopolímero ser um alimento funcional candidato à utilização como co-adjuvante na quimioterapia para prevenir efeitos colaterais. This study evaluated the mutagenic and ant mutagenic action of a biopolymer of glucose extracted from Agrobacterium radiobacter (Biopolymer of Agrobacterium radiobacter). The experiment was conducted with Swiss male mice divided into eight groups. Treatment with the biopolymer was performed in a single dose by gavage at a dose of concomitant phosphate buffer groups in the evaluation of mutagenicity, or the agent of inducing DNA damage, cyclophosphamide, the concentration of 50 mg/kg (body weight --b.w.), in groups of assessment ant mutagenic. We used the micronucleus test in peripheral blood. The blood sample was held 24 and 48 h after application of the test substances. Statistical analysis showed that the biopolymer has no mutagenic activity and it is effective in preventing damage to DNA. The percentages of damage reduction in groups of ant mutagenic were 83.9%, 89.1% and 103.1% in 24 h and 101.24%, 98.14% and 120.64% at doses of 48 to 75, 150 and 300 mg/kg (b.w.) respectively. The high percentage of damage reduction associated with the absence of mutagenic effects indicates the possibility of biopolymer chemoprotection action. It can also be considered a functional food candidate to be used as co-adjuvant chemotherapy to prevent side effects. Centro Universitário Filadélfia Departamento de Nutrição Centro de Estudo em Nutrição e Genética Toxicológica Universidade Estadual de Londrina (UEL) Centro de Ciências Agrárias Departamento de Tecnologia de Alimentos e Medicamentos Universidade Estadual Paulista Júlio de Mesquita Filho Instituto de Biociências de Rio Claro Programa de Pós-graduação em Biologia Celular e Molecular Universidade Estadual de Londrina (UEL) Centro de Ciências Biológicas Departamento de Biologia Geral Universidade Federal de Mato Grosso do Sul Coordenadoria de Educação Aberta e a Distância Programa de Pós-graduação em Ciência Animal Universidade Estadual Paulista Júlio de Mesquita Filho Instituto de Biociências de Rio Claro Programa de Pós-graduação em Biologia Celular e Molecular

Coccoloba mollis (Family Polygonaceae) is a medicinal plant popularly used in cases of memory loss, stress, insomnia, anemia, impaired vision, and sexual impotence, but the scientific literature, to date, lacks studies on the biological effects of this species, particularly with regard to cytotoxicity and induction of DNA damage. The aim of the present study was to assess in vitro (in hepatic HTC cells) ethanolic extracts of the roots and leaves of C. mollis for cytotoxicity, genotoxicity, and induction of apoptosis. For these evaluations the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cytotoxicity assay, comet assay, micronucleus test with cytokinesis block, and an in situ test for detection of apoptotic cells with acridine orange staining were used. The results showed that the extract obtained from the roots of C. mollis is more cytotoxic than that obtained from the leaves and that the reduction in cell viability observed in the MTT assay was a result, at least in part, from the induction of apoptosis. Both extracts induced DNA damage at a concentration of 20 microg/mL in the comet assay, but no genotoxicity was detected with any of the treatments carried out in the micronucleus test.

High concentrations of xenobiotics from urban and industrial wastes have contributed to the contamination of many aquatic environments. We used the comet assay to evaluate the genotoxic potential of water collected from the River Paraná, which receives a great deal of waste, at three points (Puerto Piray, Eldorado and Montecarlo) in the Misiones Province of Argentina. The in vivo comet assay used 40 freshwater clams (Corbicula fluminea) while the in vitro comet assay used Chinese hamster (Cricetulus griseus) K1 cell (CHO-K1) cultures with the mutagen ethyl methanesulfonate (EMS) as the positive control and phosphate buffered saline (PBS) as the negative control. Both assays showed statistically significant differences between the three sampling sites in relation to the negative control, the results of this preliminary study indicating that at these three sites water from the Paraná River presents genotoxic potential. Copyright © 2008, Sociedade Brasileira de Genética. Fil: Caffetti, Jacqueline Diana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Posadas | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Posadas; Argentina Fil: Mantovani, Mário S.. Universidade Estadual de Londrina; Brasil Fil: Pastori, María Cristina. Universidad Nacional de Misiones; Argentina Fil: Fernocchio, Alberto S.. Universidad Nacional de Misiones; Argentina

The use of azo dyes by different industries can cause direct and/or indirect effects on human and environmental health due to the discharge of industrial effluents that contain these toxic compounds. Several studies have demonstrated the genotoxic effects of various azo dyes, but information on the DNA damage caused by Disperse Red 1 and Disperse Orange 1 is unavailable, although these dyes are used in dyeing processes in many countries. The aim of the present study was to evaluate the mutagenic activity of Disperse Red 1 and Disperse Orange 1 using the micronucleus (MN) assay in human lymphocytes and in HepG2 cells. In the lymphocyte assay, it was found that the number of MN induced by the lowest concentration of each dye (0.2 microg/mL) was similar to that of the negative control. At the other concentrations, a dose response MN formation was observed up to 1.0 microg/mL. At higher dose levels, the number of MN decreased. For the HepG2 cells the results were similar. With both dyes a dose dependent increase in the frequency of MN was detected. However for the HepG2, the threshold for this increase was 2.0 microg/mL, while at higher doses a reduction in the MN number was observed. The proliferation index was also calculated in order to evaluate acute toxicity during the test. No differences were detected between the different concentrations tested and the negative control.

Breast cancer is one of the most common neoplasms in women and is a leading cause of cancer related deaths worldwide. Chemokines and their receptors are involved in the control of lymphocyte traffic, a critical component of systemic immunity. CXCR4 mRNA could be involved in the development of variety of diseases. Lipid peroxidation, the result of nonenzymatic autooxidation of polyunsaturated fatty acids, presents numerous harmful effects on biological systems and has been implicated in diseases like cancer. This study examined CXCR4 mRNA expression in peripheral blood cells and malondialdehyde (MDA) in plasma from blood donors and breast cancer patients.CXCR4 expression in peripheral blood cells from 59 breast cancer patients and 76 healthy blood donors was analyzed by real-time PCR. Plasma MDA was analyzed using high-performance liquid chromatography (HPLC).In all stages, MDA levels in total breast cancer patients (1.41 +/- 0.11) were significantly higher (P0.01) than those in healthy subjects (0.34 +/- 0.03). No statistically significant difference occurred between CXCR4 expression in peripheral blood cells from breast cancer patients (1.69 +/- 1.05) and the normal healthy control group (1.8 +/- 0.65). However, stage II samples differed statistically (4.3 +/- 1.72) from control, total cancer patients and stages I, III and IV samples.

The mushroom Agaricus blazei is studied for its nutraceutical potential and as a medicinal supplement. The aim of the present study was to investigate the chemoprotective effect of beta-glucan extracted from the mushroom A. blazei against DNA damage induced by benzo[a]pyrene (B[a]P), using the comet assay (genotoxicity) and micronucleus assay with cytokinesis block (mutagenicity) in a human hepatoma cell line (HepG2). To elucidate the possible beta-glucan mechanism of action, desmutagenesis or bioantimutagenesis types, three treatment protocols were tested: simultaneous, pre-treatment, and presimultaneous. The results showed that beta-glucan does not exert genotoxic or mutagenic effect, but that it does protect against DNA damage caused by B[a]P in every protocol tested. The data suggest that beta-glucan acts through binding to B[a]P or the capture of free radicals produced during its activation. On the other hand, the pre-treatment results also suggest the possibility that beta-glucan modulates cell metabolism.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T19:05:00Z No. of bitstreams: 1 S1415-47572008000100021.pdf: 78956 bytes, checksum: 47e6639a24371f4c6004a2abbcc0173f (MD5) Made available in DSpace on 2013-08-22T19:05:00Z (GMT). No. of bitstreams: 1 S1415-47572008000100021.pdf: 78956 bytes, checksum: 47e6639a24371f4c6004a2abbcc0173f (MD5) Previous issue date: 2008-01-01 Made available in DSpace on 2013-09-30T20:08:37Z (GMT). No. of bitstreams: 2 S1415-47572008000100021.pdf: 78956 bytes, checksum: 47e6639a24371f4c6004a2abbcc0173f (MD5) S1415-47572008000100021.pdf.txt: 32471 bytes, checksum: 4b76650d16eda360ce4bb8dfe66a14e6 (MD5) Previous issue date: 2008-01-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T15:17:31Z No. of bitstreams: 2 S1415-47572008000100021.pdf: 78956 bytes, checksum: 47e6639a24371f4c6004a2abbcc0173f (MD5) S1415-47572008000100021.pdf.txt: 32471 bytes, checksum: 4b76650d16eda360ce4bb8dfe66a14e6 (MD5) Made available in DSpace on 2014-05-20T15:17:31Z (GMT). No. of bitstreams: 2 S1415-47572008000100021.pdf: 78956 bytes, checksum: 47e6639a24371f4c6004a2abbcc0173f (MD5) S1415-47572008000100021.pdf.txt: 32471 bytes, checksum: 4b76650d16eda360ce4bb8dfe66a14e6 (MD5) Previous issue date: 2008-01-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Functional food investigations have demonstrated the presence of substances that could be beneficial to human health when consumed. However, the toxic effects of some substances contained in foods have been determined. Reported medicinal and nutritive properties have led to the extensive commercialization of the basidiomycete fungi Agaricus blazei Murrill (sensu Heinemann), also known as Agaricus brasiliensis Wasser et al., Agaricus subrufescens Peck or the Brazilian medical mushroom (BMM). Different methanolic extract fractions (ME) of this mushroom were submitted to the cytokinesis-block micronucleus (CBMN) clastogenic assay and the hypoxanthine-guanine phosphoribosyl transferase locus (HGPRT) assay for gene mutation, both using Chinese hamster ovary cells clone K1 (CHO-K1). The results suggest that all the fractions tested possess cytotoxic and mutagenic potential but no clastogenic effects. Further information is needed on the biochemical components of the A. blazei methanol fractions to identify any substances with cytotoxic and/or mutagenicity potential. These findings indicate that A. blazei methanolic extract should not be used due to their genotoxicity and care should be taken in the use of A. blazei by the general population until further biochemical characterization of this fungi is completed. Universidade Estadual de Londrina (UEL) Departamento de Biologia Geral Universidade Federal de São Carlos (UFSCar) Departamento de Química Universidade Estadual Paulista Universidade Estadual Paulista

OBJECTIVE: The purpose of this series is to report our experience in managing ureteral trauma, focusing on the importance of early diagnosis, correct treatment, and the impact of associated injuries on the management and morbid-mortality. MATERIALS AND METHODS: From January 1994 to December 2002, 1487 laparotomies for abdominal trauma were performed and 20 patients with ureteral lesions were identified, all of them secondary to penetrating injury. Medical charts were analyzed as well as information about trauma mechanisms, diagnostic routine, treatment and outcome. RESULTS: All patients were men. Mean age was 27 years. The mechanisms of injury were gunshot wounds in 18 cases (90%) and stab wounds in two (10%). All penetrating abdominal injuries had primary indication of laparotomy, and neither excretory urography nor computed tomography were used in any case before surgery. The diagnosis of ureteric injury was made intra-operatively in 17 cases (85%). Two ureteral injuries (10%) were initially missed. All patients had associated injuries. The treatment was dictated by the location, extension and time necessary to identify the injury. The overall incidence of complications was 55%. The presence of shock on admission, delayed diagnosis, Abdominal Trauma Index > 25, Injury Severity Score > 25 and colon injuries were associated to a high complication rate, however, there was no statistically significant difference. There were no mortalities in this group. CONCLUSIONS: A high index of suspicion is required for diagnosis of ureteral injuries. A thorough exploration of all retroperitoneal hematoma after penetrating trauma should be an accurate method of diagnosis; even though it failed in 10% of our cases.

The aqueous extract of Agaricus blazei Murill ss. Heinem, a basidiomycete native from Brazil, frequently used by popular medicine, mainly in the form of tea, was assessed to its antiviral action against herpes simplex type 1 (HSV-1) and bovine herpes type 1 (BoHV-1) in HEp-2 cell culture. Viral replication inhibition was evaluated by plaque assay and immunofluorescence test. The extract demonstrated virucide action for both viruses, being more effective against HSV-1, inhibiting its infectivity in 78.4 and 73.9% at the concentrations of 50 and 100 µg/mL, respectively moreover, reduction in 47% the number of fluorescent cells was observed for both concentrations. The extract also showed discrete therapeutic activity. These results suggest that A. blazei extract acts mainly in the viral particle, however, the effect during virus replication can not be ruled out. O extrato aquoso de Agaricus blazei Murill ss. Heinem, um basidiomiceto nativo do Brasil, usado na medicina popular, na forma de chá, foi avaliado quanto suas propriedades antivirais contra herpes simplex tipo 1 (HSV-1) e herpes bovino tipo 1 (BoHV-1) em cultura de células HEp-2. A inibição da replicação viral foi monitorada pelos ensaio de placa e reação de imunofluorescência. O extrato apresentou atividade virucida mais efetiva do que terapêutica para ambos os vírus, sendo mais efetivo portanto para HSV-1, inibindo em mais de 70% o número de plaques e em cerca de 47% o número de células apresentando fluorescência específica, nas concentrações de 50 e 100 µg/mL, nas duas técnicas utilizadas. Os resultados obtidos sugerem que o extrato aquoso de A. blazei deve agir principalmente sobre a partícula viral, embora a inibição durante o ciclo replicativo do vírus não deva ser excluída.

Teas of Bidens pilosa and Mikania glomerata are popularly consumed to medicinal ends. The capacity to induce DNA damages and mutagenic effects of these teas were evaluated, in vitro, on HTC cells, with comet assay and micronucleus test. The teas tested at various doses were prepared differently: infusion of Mikania glomerata (IM) and Bidens pilosa (IB), macerate of Mikania glomerata in 80% ethanol (MM80) and decoction of Bidens pilosa (DB). In IM and MM80, the quantity of coumarin was determined by high-performance liquid chromatography (HPLC) with UV detection. Methylmethanesulfonate was utilized as positive control, phosphate-buffered saline as negative control, 80% ethanol as solvent control and 2-aminoanthracene as drug metabolism control. The comet assay demonstrated genotoxic effects for both plants. The genotoxic potential of IB was upper than DB, showing dose-response. In the MN test, excepting IM 40 microL/mL, all treatments was not mutagenic. The effects did not show direct relation with cumarin quantity present in IM and MM80. The results demonstrated DNA damages at the highest concentrations of alcoholic macerate (10 and 20 microL/mL) and infusion of Mikania glomerata (20 and 40 microL/mL) and of Bidens pilosa infusion (40 microL/mL). Thus, both dose and preparation-form suggest caution in the phytotherapeutic use of these plants.

Considering the high number of new cancer cases in Brazil (approximately 470 000 cases in 2005) and the remarkable differences in the incidence of this disease around the world, the development of chemopreventive strategies using foods widely consumed would have a huge impact, both medically and economically. This review summarizes some of our studies conducted to verify the anti-mutagenic and anti-carcinogenic potential of some Brazilian natural dietary constituents (annatto, mushrooms, and propolis). Overall data have shown a clear role for these compounds in preventing mutation and specific preneoplastic lesions. Taken together, these agents indicate a favorable side-effect profile and may prove to be a promising alternative for cancer prevention strategies, although more investigation is needed to fully explore this issue.

Due to the need to identify new antimutagenic agents and to determine their mechanism of action, the present study examined the mechanism of action of the beta-glucan with regard to antimutagenicity using the micronucleus assay in CHO-k1 and HTC cell lines. The mutagenicity experiments were performed with three different concentrations of beta-glucan (5, 10, and 20 microg/mL), in wich only the highest dose showed mutagenic activity. In the antimutagenicity experiments, the same concentrations of beta-glucan were combined with a mutagenic agent, methylmethane sulfonate, or 2-aminoanthracene, using four different treatment protocols: pre-treatment, simultaneous treatment (simple and with pre-incubation), and post-treatment. The results indicate that the CHO-k1 cell line treated with MMS presented a chemopreventive activity for all the doses of beta-glucan in the different treatment protocols, except for the lowest dose in post-treatment. When HTC cell line treated with MMS is analysed, a chemopreventive activity can be verified for the highest dose in both pre- and post-treatment. For the simple simultaneous treatment, the three doses demonstrated efficacy, while for the simultaneous treatment with pre-incubation only the intermediate concentration was effective. In HTC treated with 2AA both the lowest dose in the pre-treatment protocol and the post-treatment protocol did not show efficacy in preventing DNA damage. The evaluation of the different protocols and the damage decrease percentages observed suggest that beta-glucan has both desmutagenic and bioantimutagenic activity. It is necessary, however, to note that efficacy and mechanism of action are subject to variation when compared the two cell lines, since in HTC, representing a drug-metabolizing system, this substance can show a diminished chemopreventive capacity.

The comet assay was used to study the sensitivity of the widely distributed freshwater bivalve mollusk Corbicula fluminea to the DNA-damaging alkylating-agent methylmethane sulfonate (MMS). This study was undertaken to ascertain if C. fluminea is a good bioindicator of pollutants in aquatic environments and identify which C. fluminea tissue is most effective and practical for genotoxicity studies. The mollusks were exposed to 0.6, 1.2 or 2.4 X 10-4 M MMS for 40 min and their hemolymph, gill tissue and digestive gland tissue assessed for the level of DNA damage and the time needed for the tissues to recovery. Regression analysis showed a direct linear dose-response relationship between MMS concentration and the number of damaged cells for hemolymph and digestive gland tissue but a quadratic relationship for gill tissue, which made the interpretation the gill tissue results difficult. The basal level of DNA damage to gill tissue was very high, possibly because gill is the organs most directly exposed to environmental toxins and mutagenic agents. Although all three types of tissue produced useful results, hemolymph and digestive gland tissue produced more reproducible and reliable results. Hemolymph was the best sample type in that it was easy to obtain and handle, while gill tissue required more manipulation to obtain cell suspensions. Our results indicate that C. fluminea is an optimal bioindicator for the determination genotoxic contaminants in aquatic environments.

Agaricus blazei (Ab) has become popularly known for its medicinal properties. Scientifically, it has been tested with regard to its capacity to protect genetic material against damage. We examined different organic extracts (methanolic extract—ME, hexanic extract—HE and n -butanolic extract—BE) and an aqueous extract (AE) of Ab, for their capacity to induce DNA damage as well as for their protective effect. Genetic damage was determined by the chromosomal aberration assay (CA) in CHO-k1 cells for all extracts and the cytokinesis block micronucleus assay (CBMN) in non drug-metabolizing (CHO-k1) and drug-metabolizing (HTC) cell lines for extract BE only. The extracts did not show clastogenicity but showed anticlastogenicity. The greatest percent reduction obtained were with BE (105%) and AE (126%) treatments in CA. BE treatment did not display genotoxicity in CHO-k1, but was genotoxic in HTC. However, BE was shown to be antigenotoxic causing decreased micronucleus frequency in HTC and CHO-k1 cells. These results suggest that all the extracts contained protective substances, but in some cases they could show a genotoxic effect with regard to metabolism. Therefore, these findings warrant caution in the use of this mushroom by the population.

Chlorophyllin (Chln), a sodium-copper salt derivative of chlorophyll, like chlorophyll-a and -b found in green plants, has been studied for its protective action against the carcinogenic effects of various physical and chemical agents and in relation to the mutagenic and clastogenic activities of genotoxic agents. The aim of the present study was to evaluate chlorophyllin in different phases of the cell cycle for clastogenicity and anticlastogenicity, the latter in reversing DNA damage induced by ethyl methane sulfonate (EMS). The test for chromosomal aberrations was performed in cultured mammalian cells (CHO-K1). The three Chln concentrations tested (6.25, 12.5 and 25 microg/ml) were not clastogenic and damage induced by EMS (1240 microg/ml) was reduced in cells treated with Chln as well during S (25-48%) and G2/S (70-80%). The results demonstrate a greater protective effectiveness of Chln against EMS during G2/S.

Testing for environmental pollutants is an ever-growing concern. Various tests in organisms have been utilized for the detection and identification of toxic substances in the air, water and soil. In the present study, we utilized the comet assay in Tilapia rendalli to conduct an environmental assessment of Lake Igapo II, a lake located in the metropolitan area of Londrina, PR-Brazil. The results demonstrated that samples from Lake Igapo II had a significantly greater number of comets, mainly in classes 2 and 3. The results suggest a genotoxicity of the aquatic environment at Lake Igapo II and that the comet assay in T. rendalli provides adequate sensitivity to be utilized as a tool in the monitoring of water pollution and environmental risk assessment.

The effects of clastogenic or mutagenic agents have rarely been studied in neotropical fish species exposed to contaminated water. In this study, the genetic damage caused by lead in the widely distributed South American fish, Hoplias malabaricus, was assessed using the comet (SCGE) assay and by testing for chromosomal aberrations. Eighteen specimens were acclimatized to laboratory conditions and then chronically exposed to contaminated food by feeding prey (Cyprinus sp.) injected intraperitoneally with doses of inorganic lead adjusted to give a contamination level of 21 mg of Pb2+.g-1 net weight of H. malabaricus. Three fish were sampled for chromosomal analysis after four doses (18 days) and another three after eight doses (41 days) of lead and the results then compared with three untreated controls kept under lead-free conditions. An additional six treated fish and three controls were sampled for the comet assay after 13 doses (64 days). Exposure to lead significantly increased the frequency of chromosomal aberrations and the frequency of tailed cell nuclei, the latter indicating DNA damage. These results show that H. malabaricus is a useful biological model for screening the clastogenic effects of lead and possibly other xenobiotics. The genetic damage seen here illustrates the need to investigate the potential effects of heavy metals on fish species in South America.