Publications by authors named "João Antônio Pegas Henriques"

135 Publications

Cytokinesis-block micronucleus cytome (CBMN-CYT) assay and its relationship with genetic polymorphisms in welders.

Mutat Res Genet Toxicol Environ Mutagen 2021 Dec 13;872:503417. Epub 2021 Oct 13.

Laboratório de Genética Toxicológica, Universidade Luterana do Brasil (ULBRA) & Universidade La Salle (UniLaSalle), Canoas, RS, Brazil. Electronic address:

Fumes generated in the welding process are composed of micrometric and nanometric particles that form when metal fumes condense. The International Agency for Research on Cancer established that many compounds derived from the welding process are carcinogenic to humans. Still, there are few studies related to the role of genetic polymorphisms. This work aimed to analyze the influence of OGG1 Ser326Cys, XRCC1 Arg280His, XRCC1 Arg194Thr, XRCC1 Arg399Gln, XRCC3 Thr241Met, GSTM1, and GSTT1 gene polymorphisms on DNA damage of 98 subjects occupationally exposed to welding fumes and 100 non exposed individuals. The results showed that individuals exposed to welding fumes with XRCC3 Thr241Thr, XRCC3 Thr241Met, and GSTM1 null genotypes demonstrated a significantly higher micronucleus frequency in lymphocytes. In contrast, individuals with XRCC1 Arg399Gln and XRCC1 Gln399Gln genotypes had significant levels of NPBs. OGG1 326 Ser/Cys, OGG1 326 Cys/Cys, XRCC1 194Arg/Thr, XRCC1 194Thr/Thr, and GSTT1 null genotypes exhibited significantly higher apoptotic values. Also, XRCC1 194Arg/Trp, XRCC1 194Thr/Thr, and GSTM1 null genotype carriers had higher necrotic levels compared to XRCC1 194Arg/Arg and GSTM1 nonnull carriers. Compositional analysis revealed the presence of iron, manganese, silicon as well as particles smaller than 2 μm that adhere to each other and form agglomerates. These results may be associated with a mixture of components, such as nitrogen dioxide, carbon monoxide, and metallic fumes, leading to significant DNA damage and cell death processes. These findings demonstrated the importance of the association between individual susceptibility and DNA damage levels due to occupational exposure to welding fumes; and constitute one of the first studies carried out in exposed workers from Colombia.
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http://dx.doi.org/10.1016/j.mrgentox.2021.503417DOI Listing
December 2021

Saccharomyces cerevisiae DNA repair pathways involved in repair of lesions induced by mixed ternary mononuclear Cu(II) complexes based on valproic acid with 1,10-phenanthroline or 2,2'- bipyridine ligands.

Mutat Res Genet Toxicol Environ Mutagen 2021 Aug-Sep;868-869:503390. Epub 2021 Aug 10.

Department of Biophysics/Department of Molecular Biology and Biotechnology/Department of Genetics, Federal University of Rio Grande do Sul, Porto Alegre, Brazil; Programas de Pós Graduação em Biotecnologia e em Ciências Médicas, Universidade do Vale do Taquari - UNIVATES, Lajeado, RS, Brazil.

The sodium valproate has been largely used as an anti-epilepsy drug and, recently, as a putative drug in cancer therapy. However, the treatment with sodium valproate has some adverse effects. In this sense, more effective and secure complexes than sodium valproate should be explored in searching for new active drugs. This study aims to evaluate the cytotoxicity of sodium valproate, mixed ternary mononuclear Cu(II) complexes based on valproic acid (VA) with 1,10-phenanthroline (Phen) or 2,2'- bipyridine (Bipy) ligands - [Cu(Valp)], [Cu(Valp)Phen] and [Cu(Valp)Bipy] - in yeast Saccharomyces cerevisiae, proficient or deficient in different repair pathways, such as base excision repair (BER), nucleotide excision repair (NER), translesion synthesis (TLS), DNA postreplication repair (PRR), homologous recombination (HR) and non-homologous end-joining (NHEJ). The results indicated that the Cu(II) complexes have higher cytotoxicity than sodium valproate in the following order: [Cu(Valp)Phen] > [Cu(Valp)Bipy] > [Cu(Valp)] > sodium valproate. The treatment with Cu(II) complexes and sodium valproate induced mutations in S. cerevisiae. The data indicated that yeast strains deficient in BER (Ogg1p), NER (complex Rad1p-Rad10p) or TLS (Rev1p, Rev3p and Rad30p) proteins are associated with increased sensitivity to sodium valproate. The BER mutants (ogg1Δ, apn1Δ, rad27Δ, ntg1Δ and ntg2Δ) showed increased sensitivity to Cu(II) complexes. DNA damage induced by the complexes requires proteins from NER (Rad1p and Rad10p), TLS (Rev1p, Rev3p and Rad30p), PRR (Rad6 and Rad18p) and HR (Rad52p and Rad50p) for efficient repair. Therefore, Cu(II) complexes display enhanced cytotoxicity when compared to the sodium valproate and induce distinct DNA lesions, indicating a potential application as cytotoxic agents.
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http://dx.doi.org/10.1016/j.mrgentox.2021.503390DOI Listing
September 2021

ZnO nanoparticles alter redox metabolism of Limnoperna fortunei.

Environ Sci Pollut Res Int 2021 Dec 23;28(48):69416-69425. Epub 2021 Jul 23.

Instituto de Biotecnologia, Universidade de Caxias do Sul (UCS), Rua Francisco Getúlio Vargas 1130, Caxias do Sul, RS, 95070-560, Brazil.

Nanoparticles such as zinc oxide nanoparticles (ZnO-NP) that are incorporated in consumer and industrial products have caused concern about their potential ecotoxicological impact when released into the environment. Bivalve mollusks are susceptible targets for nanoparticle toxicity since nanomaterials can enter the cells by endocytosis mechanisms. The aim of this study was to evaluate the influence of ZnO-NP on the redox metabolism in Limnoperna fortunei and the DNA damage after exposure to ZnO-NP. Adult bivalves were incubated with 1-, 10-, and 50-μg mL ZnO-NP for 2, 4, and 24 h. Ionic Zn release, enzymatic and non-enzymatic antioxidant activity, oxidative damage, and DNA damage were evaluated. Oxidative damage to proteins and lipids were observed after 4-h exposure and returned to baseline levels after 24 h. Superoxide dismutase levels decreased after 4-h exposure and increased after 24 h. No significant alteration was observed in the catalase activity or even DNA double-strand cleavage. The dissociation of ZnO may occur after 24 h, releasing ionic zinc (Zn) by hydrolysis, which was confirmed by the increase in the ionic Zn concentration following 24-h exposure. In conclusion, ZnO-NP were able to induce oxidative stress in exposed golden mussels. The golden mussel can modulate its own antioxidant defenses in response to oxidative stress and seems to be able to hydrolyze the nanoparticles and consequently, release Zn into the cellular compartment.
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http://dx.doi.org/10.1007/s11356-021-15257-8DOI Listing
December 2021

SARS-CoV-2 mutations in Brazil: from genomics to putative clinical conditions.

Sci Rep 2021 06 7;11(1):11998. Epub 2021 Jun 7.

Department of Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy, University of Tübingen, Tübingen, Germany.

Due to the high rate of transmissibility, Brazil became the new COVID-19 outbreak epicenter and, since then, is being monitored to understand how SARS-CoV-2 mutates and spreads. We combined genomic and structural analysis to evaluate genomes isolated from different regions of Brazil and show that the most prevalent mutations were located in the S, N, ORF3a and ORF6 genes, which are involved in different stages of viral life cycle and its interaction with the host cells. Structural analysis brought to light the positions of these mutations on protein structures, contributing towards studies of selective structure-based drug discovery and vaccine development.
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http://dx.doi.org/10.1038/s41598-021-91585-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8184806PMC
June 2021

Distinction between 2'- and 3'-Phosphate Isomers of a Fluorescent NADPH Analogue Led to Strong Inhibition of Cancer Cells Migration.

Antioxidants (Basel) 2021 May 4;10(5). Epub 2021 May 4.

Cancer Biology and Therapeutics Team, INSERM, UMR_S 938, Centre de Recherche Saint-Antoine, Sorbonne Université, F-75012 Paris, France.

Specific inhibition of NADPH oxidases (NOX) and NO-synthases (NOS), two enzymes associated with redox stress in tumor cells, has aroused great pharmacological interest. Here, we show how these enzymes distinguish between isomeric 2'- and 3'-phosphate derivatives, a difference used to improve the specificity of inhibition by isolated 2'- and 3'-phosphate isomers of our NADPH analogue NS1. Both isomers become fluorescent upon binding to their target proteins as observed by in vitro assay and in vivo imaging. The 2'-phosphate isomer of NS1 exerted more pronounced effects on NOS and NOX-dependent physiological responses than the 3'-phosphate isomer did. Docking and molecular dynamics simulations explain this specificity at the level of the NADPH site of NOX and NOS, where conserved arginine residues distinguished between the 2'-phosphate over the 3'-phosphate group, in favor of the 2'-phosphate.
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http://dx.doi.org/10.3390/antiox10050723DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8148004PMC
May 2021

Cytokinesis-block micronucleus cytome (CBMN-CYT) assay biomarkers and telomere length analysis in relation to inorganic elements in individuals exposed to welding fumes.

Ecotoxicol Environ Saf 2021 Apr 9;212:111935. Epub 2021 Feb 9.

Departamento de Biofísica, Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Instituto de Biotecnologia, Universidade de Caxias do Sul (UCS), Caxias do Sul, RS, Brazil. Electronic address:

During the welding activities many compounds are released, several of these cause oxidative stress and inflammation and some are considered carcinogenic, in fact the International Agency for Research on Cancer established that welding fumes are carcinogenic to humans. The aim of the present study was to analyze the cytotoxic and genotoxic potential of exposure to welding fumes and to determine concentrations of metals in blood and urine of occupationally exposed workers. We included 98 welders and 100 non-exposed individuals. Our results show significant increase in the frequency of micronuclei (MN), nucleoplasmic bridges (NPB), nuclear buds (NBUD) and necrotic cells (NECR) in cytokinesis-block micronucleus cytome (CBMN-Cyt) assay, as well as in the telomere length (TL) of the exposed individuals with respect to the non-exposed group. In the analysis of the concentrations of inorganic elements using PIXE method, were found higher concentrations of Cr, Fe and Cu in the urine, and Cr, Fe, Mg, Al, S, and Mn in the blood in the exposed group compared to the non-exposed group. A significant correlation was observed between MN and age and between NPB and years of exposure. Additionally, we found a significant correlation for TL in relation to MN, NPB, age and years of exposure in the exposed group. Interestingly, a significant correlation between MN and the increase in the concentration of Mg, S, Fe and Cu in blood samples of the exposed group, and between MN and Cr, Fe, Ni and Cu in urine. Thus, our findings may be associated with oxidative and inflammatory damage processes generated by the components contained in welding fumes, suggesting a high occupational risk in welding workers.
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http://dx.doi.org/10.1016/j.ecoenv.2021.111935DOI Listing
April 2021

Systems chemo-biology analysis of DNA damage response and cell cycle effects induced by coal exposure.

Genet Mol Biol 2020 26;43(3):e20190134. Epub 2020 Jun 26.

Universidade Federal do Rio Grande do Sul, Centro de Biotecnologia, Departamento de Biofísica, Porto Alegre, RS, Brazil.

Cell cycle alterations are among the principle hallmarks of cancer. Consequently, the study of cell cycle regulators has emerged as an important topic in cancer research, particularly in relation to environmental exposure. Particulate matter and coal dust around coal mines have the potential to induce cell cycle alterations. Therefore, in the present study, we performed chemical analyses to identify the main compounds present in two mineral coal samples from Colombian mines and performed systems chemo-biology analysis to elucidate the interactions between these chemical compounds and proteins associated with the cell cycle. Our results highlight the role of oxidative stress generated by the exposure to the residues of coal extraction, such as major inorganic oxides (MIOs), inorganic elements (IEs) and polycyclic aromatic hydrocarbons (PAH) on DNA damage and alterations in the progression of the cell cycle (blockage and/or delay), as well as structural dysfunction in several proteins. In particular, IEs such as Cr, Ni, and S and PAHs such as benzo[a]pyrene may have influential roles in the regulation of the cell cycle through DNA damage and oxidative stress. In this process, cyclins, cyclin-dependent kinases, zinc finger proteins such as TP53, and protein kinases may play a central role.
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http://dx.doi.org/10.1590/1678-4685-GMB-2019-0134DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7315349PMC
June 2020

Hollow cathode plasma nitriding of medical grade Ti6Al4V: A comprehensive study.

J Biomater Appl 2020 09 22;35(3):353-370. Epub 2020 Jun 22.

Área do Conhecimento de Ciências Exatas e Engenharias, Programa de Pós-Graduação em Engenharia e Ciência dos Materiais (PPGMAT), Universidade de Caxias do Sul, Caxias do Sul, Brazil.

Ti6Al4V used in biomedical applications still has several surface-related problems, such as poor bone compatibility and low wear resistance. In this work, the formation of a protective layer of titanium nitride obtained by plasma treatment in hollow cathode was studied, and the best experimental conditions were verified by a statistical factorial design of experiments. The samples were characterized in terms of their physical and chemical properties, correlating the effects of time (min) and temperature (°C). An achieved ideal condition was further analysed in terms of cytotoxicity, micro-abrasion, and electrochemical properties. The carried-out assessment has shown that nitrided condition has an improvement in wettability, microhardness, along with TixNy formation and roughness increment, when compared to pristine condition.
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http://dx.doi.org/10.1177/0885328220935378DOI Listing
September 2020

The combination of Brazilian red propolis and recombinant protein rCP01850 in the immunoprophylaxis of Corynebacterium pseudotuberculosis infection in mice.

Microb Pathog 2020 Dec 20;149:104354. Epub 2020 Jun 20.

Universidade Federal de Pelotas (UFPel), Campus Capão Do Leão, Centro de Desenvolvimento Tecnológico (CDTec), Capão Do Leão, Brazil. Electronic address:

The immunomodulatory properties of Brazilian red propolis (BRP) have been already described. Also, propolis have been proved to have antibacterial activity on Corynebacterium pseudotuberculosis. An adjuvant effect of red propolis oil was able to induce a significant anti-C. pseudotuberculosis humoral immune response. Here, we demonstrate for the first time the immunostimulant property of BRP hydroalcoholic extract (BRPHE) in a recombinant vaccine against caseous lymphadenitis. Mice BALB/c were allocated in three groups inoculated with: sterile saline solution (G1); BRPHE (G2); or BRPHE combined with the C. pseudotuberculosis rCP01850 recombinant protein (G3) in two doses within a 21-days-interval. Blood samples were collected for the total IgG, IgG1 and IgG2a measurement. Mice were challenged with a virulent C. pseudotuberculosis strain, and other 6 mice were used for IFN-γ and IL-10 levels determination after splenocyte stimulation with the recombinant antigen. G3 showed higher significant levels of antibodies on the 42nd experimental day, with a high IgG2a/IgG1 proportion. G2 and G3 presented significant production of IFN-γ and IL-10, while G3 presented the higher levels of IFN-γ (p < 0.05). After challenge, G2 showed a survival rate of 20%, while 70% of mice from G3 survived the experimental challenge. In conclusion, BRPHE used alone has immunostimulant properties specially on cellular immune response, and when used in combination with the recombinant protein rCP01850 induces cellular and humoral immune responses as well as a significant survival of inoculated mice.
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http://dx.doi.org/10.1016/j.micpath.2020.104354DOI Listing
December 2020

DNA repair and metabolic gene polymorphisms affect genetic damage due to diesel engine exhaust exposure.

Environ Sci Pollut Res Int 2020 Jun 3;27(16):20516-20526. Epub 2020 Apr 3.

Departamento de Biofísica, Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.

Diesel engine exhaust (DEE) is a complex mixture of toxic gases, halogenated aromatic hydrocarbons, alkyl polycyclic aromatic hydrocarbons, polycyclic aromatic hydrocarbons, benzene derivatives, metals and diesel exhaust particles (DEPs) generated from the incomplete combustion of diesel fuel. Many of the compounds in this mixture can cause oxidative damage to DNA and are considered carcinogenic for humans. Further, chronic DEE exposure increases risks of cardiovascular and pulmonary diseases. Despite these pervasive health risks, there is limited and inconsistent information regarding genetic factors conferring susceptibility or resistance to DEE genotoxicity. The present study evaluated the effects of polymorphisms in two base excision repair (BER) genes (OGG1 Ser326Cys and XRCC1 Arg280His), one homologous recombination (HRR) gene (XRCC3 Thr241Met) and two xenobiotic metabolism genes (GSTM1 and GSTT1) on the genotoxicity profiles among 123 mechanics exposed to workplace DEE. Polymorphisms were determined by PCR-RFLP. In comet assay, individuals with the GSTT1 null genotype demonstrated significantly greater % tail DNA in lymphocytes than those with non-null genotype. In contrast, these null individuals exhibited significantly lower frequencies of binucleated (BN) cells and nuclear buds (NBUDs) in buccal cells than non-null individuals. Heterozygous hOGG1 326 individuals (hOGG1 326 Ser/Cys) exhibited higher buccal cell NBUD frequency than hOGG1 326 Ser/Ser individuals. Individuals carrying the XRCC3 241 Met/Met polymorphism also showed significantly higher buccal cell NBUD frequencies than those carrying the XRCC3 241 Thr/Thr polymorphism. We found a high flow of particulate matter with a diameter of < 2.5 μm (PM) in the workplace. The most abundant metals in DEPs were iron, copper, silicon and manganese as detected by transmission electron microscopy-energy-dispersive X-ray spectroscopy (TEM-EDX). Scanning electron microscopy (SEM-EDS) revealed particles with diameters smaller than PM, including nanoparticles forming aggregates and agglomerates. Our results demonstrate the genotoxic effects of DEE and the critical influence of genetic susceptibility conferred by DNA repair and metabolic gene polymorphisms that shed light into the understanding of underlying mechanisms.
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http://dx.doi.org/10.1007/s11356-020-08533-6DOI Listing
June 2020

Investigation of plasma treatment on UHMWPE surfaces: Impact on physicochemical properties, sterilization and fibroblastic adhesion.

Mater Sci Eng C Mater Biol Appl 2019 Sep 18;102:264-275. Epub 2019 Apr 18.

Área do Conhecimento de Ciências Exatas e Engenharias, Universidade de Caxias do Sul, Caxias do Sul, RS 95070-560, Brazil.

Ultra-high molecular weight polyethylene (UHMWPE) is a prevailing bearing material applied in joint arthroplasty. Despite not being a novel biomaterial, its debris as consequence of long application and surface properties usually still lead to short lifespan. Many of the drawbacks are associated with sterilization methods that degrade the surface properties of UHMWPE. This work aims at improving the sterilizing treatment and also increasing material wettability, without losing bulk properties, which are essential for an orthopedic bearing. Cold plasma in hollow cathode setting was used for the material surface functionalization. Samples were characterized through contact angle (WCA), x-ray diffraction (XRD), optical microscopy, attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and profilometry. Optimal points based on immediate surface wettability, shelf time and sterilization efficacy were chosen for biocompatibility evaluation. When comparing cell viability through MTT among treated samples (OP, OP and UV), a slight reduction in OP viability could be seen after 7 days incubation, which is also observed in Giemsa staining and SEM images. In late incubation, OP loses its hydrophilic character and displays higher cell adhesion than its counterparts UV and OP. At the end, OP showed less cells growing over the biomaterial after 7 days exposition compared to OP and UV. OP presented a more hydrophobic surface and improved cell adhesion, differently from OP and UV, which maintained their wettability conditions in late incubation. Cell analysis results indicate that surface wetting influences cell morphology and consequent cell adhesion, in which more hydrophobic surfaces are shown to favor fibroblast adhesion properties.
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http://dx.doi.org/10.1016/j.msec.2019.04.048DOI Listing
September 2019

Cytotoxic and genotoxic effects in mechanics occupationally exposed to diesel engine exhaust.

Ecotoxicol Environ Saf 2019 Apr 3;171:264-273. Epub 2019 Jan 3.

Universidad Simón Bolívar, Facultad de Ciencias Básicas y Biomédicas, Barranquilla, Colombia. Electronic address:

Diesel engine exhaust (DEE), which is the product of diesel combustion, is considered carcinogenic in humans. It comprises toxic gases, polycyclic aromatic hydrocarbons (PAHs) and particulate matter which can reach the pulmonary parenchyma and trigger various diseases, including cancer. The aim of the present study was to evaluate the potential cytotoxic and genotoxic effects of DEE exposure on peripheral blood and buccal epithelial cells in mechanics occupationally exposed to DEE. We recruited 120 exposed mechanics and 100 non-exposed control individuals. Significant differences were observed between the two groups in terms of percentage of tail DNA and damage index (DI) in the alkaline comet assay; levels of biomarkers by cytokinesis-block micronucleus cytome (CBMN-Cyt) assay; frequency of micronucleus (MN), nucleoplasmic bridge (NPB), nuclear bud (NBUD) and apoptotic cells (APOP) and levels of biomarkers for micronucleus, karyorrhexis (KRX), karyolysis (KRL) and condensed chromatin (CC) by the buccal micronucleus cytome (BM-Cyt) assay. A significant and positive correlation was found between the frequency of MN in lymphocytes and buccal cells in the exposed group. Also, there was a significant correlation between age and percentage of tail DNA and DI in the comet assay, APOP and MN in the CBMN-Cyt assay and NBUD and MN in the BM-Cyt assay. Additionally, we found a positive and significant correlation of MN frequency in lymphocytes and buccal cells and age and MN frequency in lymphocytes with the time of service (years). Regarding lifestyle-related factors, a significant correlation was observed between meat and vitamin consumption and NBUD formation on CBMN-Cyt and between meat consumption and MN formation on CBMN-Cyt. Of the BM-Cyt biomarkers, there was a correlation between alcohol consumption and NBUD formation and between binucleated cell (BN), pyknosis (PYC), CC and KRL occurrence and family cancer history. These results are the first data in Colombia on the cytotoxic and genotoxic effects induced by continuous exposure to DEE and thus showed the usefulness of biomarkers of the comet, CBMN-Cyt and BM-Cyt assays for human biomonitoring and evaluation of cancer risk in the exposed populations.
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http://dx.doi.org/10.1016/j.ecoenv.2018.12.067DOI Listing
April 2019

Polyurethane/poly(d,l-lactic acid) scaffolds based on supercritical fluid technology for biomedical applications: Studies with L929 cells.

Mater Sci Eng C Mater Biol Appl 2019 Mar 28;96:539-551. Epub 2018 Nov 28.

Center for Exact Sciences and Technology, University of Caxias do Sul, RS, Brazil.

Biomaterials can be applied in tissue engineering as scaffolds that resemble the extracellular matrix functioning as a temporary structure for cell proliferation and reconstruction of new organs and tissues. To evaluate the potential use of scaffolds as a biomaterial, this work proposes the development and characterization of polyurethane (PU), poly(D,L-lactic acid) (PDLLA) and polyurethane/poly(d,l-lactic acid) (PU/PDLLA) scaffolds produced by gas foaming technique. The neat polymers and the blends were characterized, in film form, by gel permeation chromatography (GPC), thermogravimetry (TG), differential scanning calorimetry (DSC) and field emission gun scanning electron microscopy (FEG-SEM). After supercritical fluid technology, in scaffolds form, the samples were characterized by FEG-SEM, pore size, density, cytotoxicity and cell adhesion. For film characterization the PU/PDLLA sample presented intermediate characteristics compared to the neat polymers, exhibiting the behavior of both polymers in the sample without phase separation in the FEG-SEM micrograph and bimodal molar weight distribution by GPC. The scaffolds showed interconnectivity and pore size of 141 μm ± 108 μm for PUsc and 52 μm ± 32 μm for PDLLAsc. The PU/PDLLAsc exhibited a bimodal structure in which the PU in the mixture revealed pores of 75 μm ± 57 μm, while for PDLLA, the pore size was 19 μm ± 12 μm. In vitro tests confirmed the adhesion of L929 cells to PUsc, PDLLAsc and PU/PDLLAsc, showing no cytotoxic effect. Finally, it can be concluded that it is possible to produce PU, PDLLA and PU/PDLLA scaffolds by supercritical fluid, which may be applied as biomaterials.
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http://dx.doi.org/10.1016/j.msec.2018.11.054DOI Listing
March 2019

Piperlongumine Induces Apoptosis in Colorectal Cancer HCT 116 Cells Independent of Bax, p21 and p53 Status.

Anticancer Res 2018 Nov;38(11):6231-6236

Laboratory of Genomics, Proteomics and DNA Repair, Biotechnology Institute, University of Caxias do Sul, Caxias do Sul, Brazil

Background/aim: Colorectal cancer is a common type of cancer with reported resistance to treatment, in most cases due to loss of function of apoptotic and cell-cycle proteins. Piperlongumine (PPLGM) is a natural alkaloid isolated from Piper species, with promising anti-cancer properties. This study investigated whether PPLGM is able to induce cell death in colorectal carcinoma HCT 116 cells expressing wild-type or deficient in Bax, p21 or p53.

Materials And Methods: PPLGM was extracted from roots of Piper tuberculatum. Cell viability was determined by reduction of 3-(4,5-dimethilthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and clonogenic assay. Cell death was evaluated by acridine orange/ethidium bromide staining and flow cytometry. Plasmid cleavage activity and circular dichroism DNA interaction were also analyzed.

Results: PPLGM induced selective cell death in all cell lines (IC range from 10.7 to 13.9 μM) with an increase in the number of late apoptotic cells and different profiles in cell-cycle distribution. Plasmid DNA analysis showed that PPLGM does not interact directly with DNA.

Conclusion: This paper suggests that PPLGM may be a promising candidate in colorectal cancer therapy.
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http://dx.doi.org/10.21873/anticanres.12978DOI Listing
November 2018

Brazilian red propolis: Chemical composition and antibacterial activity determined using bioguided fractionation.

Microbiol Res 2018 Sep 4;214:74-82. Epub 2018 May 4.

Laboratory of Biotechnology of Natural and Synthetics Products, University of Caxias do Sul, Brazil. Electronic address:

The indiscriminate use of antibiotics is causing an increase in bacterial resistance, complicating therapeutic planning. In this context, natural products have emerged as major providers of bioactive compounds. This work performs a bioguided study of Brazilian red propolis to identify compounds with antibacterial potential and to evaluate their cytotoxicity against non-tumour cells. Using bioguided fractionation performed with the hydroalcoholic extract of red propolis from Alagoas, it was possible to obtain subfractions with remarkable bacteriostatic activity compared with the precursor fractions. The SC2 subfraction was highlighted and showed the best results with minimal inhibitory concentrations (MICs) of 56.75, 28.37, 454.00, and 227.00 μg mL against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa, respectively. However, this study also revealed a cytotoxic effect against the non-tumour Vero cell line. Furthermore, through chemical analyses using high resolution mass spectrometry, high performance liquid chromatography with UV detection, and gas chromatography coupled to mass spectrometry, we verified the presence of important marker compounds in the fractions and extracts, including formononetin (m/z 267.0663), biochanin A (m/z 283.0601), and liquiritigenin (m/z 255.0655). The results obtained in this study suggest an important antibacterial potential of red propolis subfractions. In this context, the bioguided fractionation has been a useful process, due to its ability to isolate and concentrate active compounds in a logical and rational way.
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http://dx.doi.org/10.1016/j.micres.2018.05.003DOI Listing
September 2018

Influence of PARP-1 inhibition in the cardiotoxicity of the topoisomerase 2 inhibitors doxorubicin and mitoxantrone.

Toxicol In Vitro 2018 Oct 15;52:203-213. Epub 2018 Jun 15.

Laboratory of Genetic Toxicology, Federal University of Health Sciences of Porto Alegre (UFCSPA), Sarmento Leite st., 245, Porto Alegre, RS, Brazil; Graduate Program in Cellular and Molecular Biology, Federal University of Rio Grande do Sul (UFRGS), Bento Gonçalves av., 9500, Porto Alegre, RS, Brazil.

Doxorubicin (DOX) and Mitoxantrone (MTX) are very effective drugs for a range of tumors despite being highly cardiotoxic. DNA topoisomerase 2 beta (Top2ß) was revealed as key mediator of DOX-induced cardiotoxicity, although ROS generation is also an important mechanism. Oxidative stress is also an important issue in MTX-induced cardiotoxicity that is manifested by mitochondrial dysfunction. Studies have demonstrated the relationship between PARP-1 overactivation and cell viability in DOX-treated cardiomyocytes. In reference of MTX, data regarding PARP-1 overactivation as the mechanism responsible for cardiotoxicity is difficult to find. The aim of this study was to evaluate the influence of PARP-1 inhibitor DPQ on DOX- and MTX-mediated cardiotoxicity. Cells were exposed for 24 h to DOX or MTX in the presence or absence of DPQ. Viability, apoptosis, and genotoxicity assays were carried out. Immunofluorescence of phosphorylated histone H2AX was analyzed in H9c2 cells and cardiomyocytes from neonatal rats. Results demonstrated that DPQ co-treatment increases DOX-induced apoptosis in H9c2 cells. DPQ also prevents DOX and MTX-ROS generation in part by increasing SOD and CAT activities. Furthermore, DPQ co-treatment increased the generation of DNA strand breaks by DOX and MTX whilst also inducing phosphorylation of H2AX, MRE11, and ATM in H9c2 cells. Our results demonstrated that as well as increasing DNA damage and inducing apoptotic cell death, DPQ enhances DOX- and MTX-mediated cytotoxicity in H9c2.
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http://dx.doi.org/10.1016/j.tiv.2018.06.013DOI Listing
October 2018

Chemical composition, immunostimulatory, cytotoxic and antiparasitic activities of the essential oil from Brazilian red propolis.

PLoS One 2018 1;13(2):e0191797. Epub 2018 Feb 1.

Centro de Desenvolvimento Tecnológico (CDTEc), Universidade Federal de Pelotas (UFPel), Campus Capão do Leão, Capão do Leão, Rio Grande do Sul, Brazil.

Most studies of Brazilian red propolis have explored the composition and biological properties of its ethanolic extracts. In this work, we chemically extracted and characterized the essential oil of Brazilian red propolis (EOP) and assessed its adjuvant, antiparasitic and cytotoxic activities. The chemical composition of EOP was analyzed using gas chromatography with mass spectrometry (GC-MS). EOP was tested for in vitro activity against Trichomonas vaginalis (ATCC 30236 isolate); trophozoites were treated with different concentrations of EOP (ranging from 25 to 500 μg/mL) in order to establish the MIC and IC50 values. A cytotoxicity assay was performed in CHO-K1 cells submitted to different EOP concentrations. BALB/c mice were used to test the adjuvant effect of EOP. The animals were divided in 3 groups and inoculated as follows: 0.4 ng/kg BW EOP (G1); 50 μg of rCP40 protein (G2); or a combination of 0.4 ng/kg BW EOP and 50 μg of rCP40 (G3). Total IgG, IgG1 and IgG2a levels were assessed by ELISA. The major constituent compounds of EOP were methyl eugenol (13.1%), (E)-β-farnesene (2.50%), and δ-amorphene (2.3%). Exposure to EOP inhibited the growth of T. vaginalis, with an IC50 value of 100 μg/mL of EOP. An EOP concentration of 500 μg/mL was able to kill 100% of the T. vaginalis trophozoites. The EOP kinetic growth curve showed a 36% decrease in trophozoite growth after a 12 h exposure to 500 μg/mL of EOP, while complete parasite death was induced at 24 h. With regard to CHO-K1 cells, the CC50 was 266 μg/mL, and 92% cytotoxicity was observed after exposure to 500 μg/mL of EOP. Otherwise, a concentration of 200 μg/mL of EOP was able to reduce parasite proliferation by 70% and was not cytotoxic to CHO-K1 cells. As an adjuvant, a synergistic effect was observed when EOP was combined with the rCP40 protein (G3) in comparison to the administration of each component alone (G1 and G2), resulting in higher concentrations of IgG, IgG1 and IgG2a. EOP is constituted by biologically active components with promising antiparasitic and immunostimulatory activities and can be investigated for the formulation of new vaccines or trichomonacidal drugs.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0191797PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5794096PMC
March 2018

Intratracheal instillation of coal and coal fly ash particles in mice induces DNA damage and translocation of metals to extrapulmonary tissues.

Sci Total Environ 2018 Jun 30;625:589-599. Epub 2017 Dec 30.

Universidade Federal do Rio de Janeiro, Instituto de Biofisica Carlos Chagas Filho, Rio de Janeiro, Brazil. Electronic address:

Continuous exposure to coal mining particles can cause a variety of lung diseases. We aimed to evaluate the outcomes of exposure to detailed characterized coal and coal fly ash (CFA) particles on DNA, lung and extrapulmonary tissues. Coal samples (COAL11 and COAL16) and CFA samples (CFA11 and CFA16) were included in this study. Intending to enhance the combustion process COAL16 was co-fired with a mixture of fuel oil and diesel oil, producing CFA16. Male BALB/c mice were intratracheally instilled with coal and CFA particles. Measurements were done 24h later. Results showed significant rigidity and obstruction of the central airways only for animals acutely exposed to coal particles. The COAL16 group also showed obstruction of the peripheral airways. Mononuclear cells were recruited in all treatment groups and expression of cytokines, particularly TNF-α and IL-1β, was observed. Only animals exposed to COAL16 showed a significant expression of IL-6 and recruitment of polymorphonuclear cells. DNA damage was demonstrated by Comet assay for all groups. Cr, Fe and Ni were detected in liver, spleen and brain, showing the efficient translocation of metals from the bloodstream to extrapulmonary organs. These effects were associated with particle composition (oxides, hydroxides, phosphates, sulfides, sulphates, silciates, organic-metalic compounds, and polycyclic aromatic hidrocarbons) rather than their size. This work provides state of knowledge on the effects of acute exposure to coal and CFA particles on respiratory mechanics, DNA damage, translocation of metals to other organs and related inflammatory processes.
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http://dx.doi.org/10.1016/j.scitotenv.2017.12.283DOI Listing
June 2018

Chemical characterization and cytotoxic, genotoxic, and mutagenic properties of Baccharis trinervis (Lam, Persoon) from Colombia and Brazil.

J Ethnopharmacol 2018 Mar 1;213:210-220. Epub 2017 Nov 1.

Departamento de Biofísica/Centro de Biotecnologia-UFRGS, Porto Alegre- RS-Brasil.; Programa de Pós Graduação em Biologia Celular e Molecular (PPGBCM), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil; Centro de Ciências Exatas e de Tecnologia, Instituto de Biotecnologia, Universidade de Caxias do Sul - UCS Caxias do Sul - RS, Brazil. Electronic address:

Pharmacology Relevance: Baccharis trinervis (Lam, Persoon) leaves are used in the traditional medicine for the treatment of high fevers, edema, inflammation, sores and muscle cramps, snakebites and as antiseptic.

Aim Of The Study: To investigate the cytotoxic, genotoxic, and mutagenic effects of extracts and fractions of B. trinervis from Brazil and Colombia in Chinese Hamster Ovary (CHO) cells, and to examine the mutagenic activity in Salmonella typhimurium.

Material And Methods: Aqueous extracts (AE) of aerial parts of B. trinervis from Brazil (B) and Colombia (C) were fractioned in ethyl acetate fraction (EAF), butanol extract (BF), and aqueous residue fraction (ARF). Qualitative chemical screening and determination of total flavonoid content were made. Identification of chemical constituents was performed by High Performance Liquid Chromatography (HPLC) and High Resolution Mass Spectrometry (HRMS). For the in vitro tests, CHO cells were treated for 3h with extracts and fractions. The cytotoxic activity was evaluated by clonal survival and 3-(4.5-dimethylthiazole-2-yl)-2.5-biphenyl tetrazolium bromide reduction assay (MTT). Genotoxic and mutagenic effects were evaluated by the alkaline comet assay and Cytokinesis-blockage micronucleus test (CBMN), respectively. Additionally, Salmonella/microsome assay was carried out to determinate the mutagenic effects in EAF from Brazil and Colombia.

Results: Phytochemical analyses indicated the presence of saponins and flavonoids. AE and EAF were the samples with the highest quantity of total flavonoids. HPLC showed the presence of luteolin only in AEC, and caffeic acid, ellagic acid, rosmarinic acid, and rutin were identified in AEB and AEC (AEC>AEB). The HRMS in positive mode of EAFB and EAFC showed presence of two carboxylic acids, coumarin, and two terpenoids. In addition, were identified one terpenoid and two carboxylic acids in AE, BF and ARF of B. trinervis from both countries in negative mode. Dose-dependent cytotoxic effects were observed in CHO cells treated with B. trinervis extracts and fractions by using clonal survival and MTT at concentrations higher than 0.05mg/mL. All the extracts and fractions induced DNA strand breaks in CHO cells with dose-dependent response, mostly EAFB and EAFC. The EAF from Brazil and Colombia showed mutagenic effect at 0.5mg/mL, while the other fractions did not show a significant difference in relation to the control. No mutagenic effects were found in EAF from both countries by the Salmonella/microsome assay.

Conclusions: Cytotoxic and genotoxic effects were demonstrated in all extracts and fractions used, although only EAF showed mutagenic effects by CBMN, but not by Salmonella/microsome assay. Our results suggest that flavonoids, phenylpropanoids, coumarins, and diterpenes may be responsible for the cytotoxic, genotoxic and mutagenic effects observed.
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http://dx.doi.org/10.1016/j.jep.2017.10.027DOI Listing
March 2018

Deletion of eIF2β lysine stretches creates a dominant negative that affects the translation and proliferation in human cell line: A tool for arresting the cell growth.

Cancer Biol Ther 2017 Aug 10;18(8):560-570. Epub 2017 Jul 10.

k Biotechnology Institute , Universidade de Caxias do Sul, Caxias do Sul (RS) and Instituto Brasileiro de Saúde , Porto Alegre (RS) , Brazil.

Background: Eukaryote initiation factor 2 subunit β (eIF2β) plays a crucial role in regulation protein synthesis, which mediates the interaction of eIF2 with mRNA. eIF2β contains evolutionarily conserved polylysine stretches in amino-terminal region and a zinc finger motif in the carboxy-terminus.

Methods: The gene eIF2β was cloned under tetracycline transcription control and the polylysine stretches were deleted by site-directed mutagenesis (eIF2βΔ3K). The plasmid was transfected into HEK 293 TetR cells. These cells were analyzed for their proliferative and translation capacities as well as cell death rate. Experiments were performed using gene reporter assays, western blotting, flow cytometry, cell sorting, cell proliferation assays and confocal immunofluorescence.

Results: eIF2βΔ3K affected negatively the protein synthesis, cell proliferation and cell survival causing G2 cell cycle arrest and increased cell death, acting in a negative dominant manner against the native protein. Polylysine stretches are also essential for eIF2β translocated from the cytoplasm to the nucleus, accumulating in the nucleolus and eIF2βΔ3K did not make this translocation.

Discussion: eIF2β is involved in the protein synthesis process and should act in nuclear processes as well. eIF2βΔ3K reduces cell proliferation and causes cell death. Since translation control is essential for normal cell function and survival, the development of drugs or molecules that inhibit translation has become of great interest in the scenario of proliferative disorders. In conclusion, our results suggest the dominant negative eIF2βΔ3K as a therapeutic strategy for the treatment of proliferative disorders and that eIF2β polylysine stretch domains are promising targets for this.
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http://dx.doi.org/10.1080/15384047.2017.1345383DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5653189PMC
August 2017

Antitumor activity of Brazilian red propolis fractions against Hep-2 cancer cell line.

Biomed Pharmacother 2017 Jul 13;91:951-963. Epub 2017 May 13.

Laboratory of Genomics, Proteomics and DNA Repair, Biotechnology Institute, University of Caxias do Sul, RS, Brazil. Electronic address:

Continuous increases in the rates of tumor diseases have highlighted the need for identification of novel and inexpensive antitumor agents from natural sources. In this study, we investigated the effects of enriched fraction from hydroalcoholic Brazilian red propolis extract against Hep-2 cancer cell line. Initially 201 fractions were arranged in 12 groups according to their chromatographic characteristics (A-L). After an in vitro cell viability screening, J and L were further selected as promising enriched fractions for this study. The chemical characterization was performed and Biochanin A, Formononetin, and Liquiritigenin compounds were quantified. Through MTT viability assay and morphological changes observed by Giemsa and DAPI staining, the results showed that red propolis inhibited cancer cells growth. Flow cytometry results indicated effects that were partly mediated through programmed cell death as confirmed by externalization of phosphatidylserine, DNA cleaved assay, increase at SUB G1-G0 phase in cell cycle analysis and loss of mitochondrial membrane potential. In conclusion, our results demonstrated that red propolis enriched fractions promoted apoptotic effects in human cancer cells through the mechanisms involving mitochondrial perturbation. Therefore, red propolis fractions contain candidate agents for adjuvant cancer treatment, which further studies should elucidate the comprehensive mechanistic pathways.
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http://dx.doi.org/10.1016/j.biopha.2017.05.027DOI Listing
July 2017

Anti-mitotic agents: Are they emerging molecules for cancer treatment?

Pharmacol Ther 2017 May 4;173:67-82. Epub 2017 Feb 4.

Biotechnology Center of the Federal University of Rio Grande do Sul, Department of Molecular Biology and Biotechnology, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil. Electronic address:

Mutations in cancer cells frequently result in cell cycle alterations that lead to unrestricted growth compared to normal cells. Considering this phenomenon, many drugs have been developed to inhibit different cell-cycle phases. Mitotic phase targeting disturbs mitosis in tumor cells, triggers the spindle assembly checkpoint and frequently results in cell death. The first anti-mitotics to enter clinical trials aimed to target tubulin. Although these drugs improved the treatment of certain cancers, and many anti-microtubule compounds are already approved for clinical use, severe adverse events such as neuropathies were observed. Since then, efforts have been focused on the development of drugs that also target kinases, motor proteins and multi-protein complexes involved in mitosis. In this review, we summarize the major proteins involved in the mitotic phase that can also be targeted for cancer treatment. Finally, we address the activity of anti-mitotic drugs tested in clinical trials in recent years.
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http://dx.doi.org/10.1016/j.pharmthera.2017.02.007DOI Listing
May 2017

Essential Oil Lacks Mutagenic Activity in the /Microsome and Micronucleus Assays.

ScientificWorldJournal 2016;2016:3694901. Epub 2016 Nov 7.

Programa de Pós-Graduação em Ciências Veterinárias, UFRGS, Porto Alegre, RS, Brazil; Laboratório de Produtos Naturais/Fitoquímica-Farmacologia e Toxicologia Veterinária, Departamento de Farmacologia, UFRGS, Porto Alegre, RS, Brazil; Programa de Pós-Graduação em Farmacologia e Terapêutica, UFRGS, Porto Alegre, RS, Brazil.

The present study aimed to investigate the mutagenic activity of essential oil. The most abundant compounds identified by GC-MS were -terpinene (25.73%), -terpinene (17.35%), terpinen-4-ol (17.24%), and sabinene (10.8%). Mutagenicity was evaluated by the /microsome test using the preincubation procedure on TA98, TA97a, TA100, TA102, and TA1535 strains, in the absence or in the presence of metabolic activation. Cytotoxicity was detected at concentrations higher than 0.04 L/plate in the absence of S9 mix and higher than 0.08 L/plate in the presence of S9 mix and no gene mutation increase was observed. For the mammalian cell micronucleus test, V79 Chinese hamster lung fibroblasts were used. Cytotoxicity was only observed at concentrations higher than or equal to 0.05 g/mL. Moreover, when tested in noncytotoxic concentrations, essential oil was not able to induce chromosome mutation. The results from this study therefore suggest that essential oil is not mutagenic at the concentrations tested in the /microsome and micronucleus assays.
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http://dx.doi.org/10.1155/2016/3694901DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5116495PMC
November 2017

Transplantation of bone marrow mononuclear cells prolongs survival, delays disease onset and progression and mitigates neuronal loss in pre-symptomatic, but not symptomatic ALS mice.

Neurosci Lett 2016 10 22;633:182-188. Epub 2016 Sep 22.

Centro de Pesquisa Pré-Clínica, Instituto do Cérebro do Rio Grande do Sul - Brain Institute (BraIns), Porto Alegre, RS, Brazil; Laboratório de Neurociências, Instituto do Cérebro do Rio Grande do Sul - Brain Institute (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, RS, Brazil. Electronic address:

Cell-based therapy provides a novel strategy to restore lost neurons or modulate the degenerating microenvironment in amyotrophic lateral sclerosis (ALS). This study verified the therapeutic potential of bone marrow mononuclear cells (BMMCs) in SOD1 mice. BMMCs were obtained from enhanced green fluorescent protein (EGFP) transgenic C57BL/6 mice (BMMCs) or from SOD1 transgenic mice (BMMCs) and given to mice at the pre-symptomatic or late symptomatic stage. Survival, body weight and motor performance data were recorded. DNA integrity was evaluated using the alkaline comet assay. The spinal cords were collected to assess motoneuron preservation and cell migration. BMMCs and BMMCs transplantation to pre-symptomatic SOD1 mice prolonged survival and delayed disease progression. The effects were more significant for the BMMC-transplanted mice. In late symptomatic mice, BMMCs promoted a discrete increase in survival, without other clinical improvements. DNA from BMMCs and BMMCs was found in the spinal cords of transplanted animals. DNA damage was not modified by BMMCs in any of the studied groups. Despite positive behavioral effects observed in our study, the limited results we observed for late transplanted mice call for caution before clinical application of BMMCs in ALS.
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http://dx.doi.org/10.1016/j.neulet.2016.09.030DOI Listing
October 2016

Cytotoxicity and genotoxicity induced by coal and coal fly ash particles samples in V79 cells.

Environ Sci Pollut Res Int 2016 Dec 16;23(23):24019-24031. Epub 2016 Sep 16.

Departamento de Biofísica, Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.

Exposure to coal and coal ashes can cause harmful effects in in vitro and in vivo systems, mainly by the induction of oxidative damage. The aim of this work was to assess cytotoxic and genotoxic effects using the V79 cell line treated with coal and coal fly ash particles derived from a coal power plant located in Santa Catarina, Brazil. Two coal samples (COAL11 and COAL16) and two coal fly ash samples (CFA11 and CFA16) were included in this study. COAL16 was co-firing with a mixture of fuel oil and diesel oil. The comet assay data showed that exposure of V79 cells to coal and coal fly ash particles induced primary DNA lesions. Application of lesion-specific endonucleases (FPG and ENDO III) demonstrated increased DNA effects indicating the presence of high amounts of oxidative DNA lesions. The cytokinesis-block micronucleus cytome assay analysis showed that exposure of V79 cells to high concentrations of coal and coal fly ash particles induced cytotoxic effects (apoptosis and necrosis) and chromosomal instability (nucleoplasmic bridges, nuclear buds, and micronucleus (MN) formation). These results may be associated with compounds contained in the surface of the particles as hazardous elements, ultrafine/nanoparticles, and polycyclic aromatic hydrocarbons (PAHs) which were detected in the samples. Graphical abstract ᅟ.
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http://dx.doi.org/10.1007/s11356-016-7623-zDOI Listing
December 2016

Antimutagenic and antioxidant properties of the aqueous extracts of organic and conventional grapevine Vitis labrusca cv. Isabella leaves in V79 cells.

J Toxicol Environ Health A 2016 ;79(18):825-36

a Departamento de Biofísica/Centro de Biotecnologia , Instituto de Biociências, Universidade Federal do Rio Grande do Sul) , Porto Alegre , Rio Grande do Sul , Brazil.

Grapes are one of the most commonly consumed fruit, in both fresh and processed forms; however, a significant amount is disposed of in the environment. Searching for a use of this waste, the antigenotoxic, antimutagenic, and antioxidant activities of aqueous extracts from organic and conventional Vitis labrusca leaves were determined using V79 cells as model. The antigenotoxic activity was analyzed by the alkaline comet assay using endonuclease III and formamidopyrimidine DNA glycosylase enzymes. The antimutagenic property was assessed through the micronucleus (MN) formation, and antioxidant activities were assessed using 2',7'-dichlorodihydrofluorescin diacetate (DCFH-DA) assay and 2,2-diphenyl-1-picrylhydrazyl (DPPH(●)) radical scavenging, as well as with superoxide dismutase (SOD) and catalase (CAT) activity assays. In addition, phenolic content and ascorbic acid levels of both extracts were determined. Data showed that both organic and conventional grapevine leaves extracts possessed antigenotoxic and antimutagenic properties. The extract of organic leaves significantly reduced intracellular reactive oxygen species (ROS) levels in V79 cells, and displayed greater ability for DPPH(●) scavenging and higher SOD and CAT activities than extract from conventional leaves. Further, the extract from organic leaves contained higher phenolic and ascorbic acid concentrations. In summary, extracts from organic and conventional grape leaves induced important in vitro biological effects.
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http://dx.doi.org/10.1080/15287394.2016.1190675DOI Listing
May 2017

Cytotoxic, mutagenicity, and genotoxicity effects of guanylhydrazone derivatives.

Mutat Res Genet Toxicol Environ Mutagen 2016 Aug 7;806:1-10. Epub 2016 Jun 7.

Department of Biophysics/Biotechnology Center, Federal University of Rio Grande do Sul, Bento Gonçalves 9500, 91501-970, Porto Alegre, RS, Brazil. Electronic address:

Several studies have reported that guanylhydrazones display a variety of desirable biological properties, such as antihypertensive, antibacterial, and antimalarial behaviour. They furthermore promote anti-pneumocystosis and anti-trypanosomiasis, exhibit antitumor activity, and show significant cytotoxicity against cancer cell lines. In this work, we have evaluated the cytotoxicity, mutagenicity, and genotoxicity of two guanylhydrazones derivatives, (E)-2-[(2,3-dimethoxyphenyl) methylene] hydrazine carboxymidamide hydrochloride (2,3-DMeB) and (E)-2-[(3,4-dimethoxyphenyl) methylene] hydrazine carboxymidamide hydrochloride (3,4-DMeB), in different biological models. Both 2,3-DMeB and 3,4-DMeB induce weak cytotoxic and mutagenic effects in bacteria and yeast. The genotoxicity of these compounds was determined in a fibroblast cell line (V79) using alkaline comet assay, as well as a modified comet assay with bacterial enzymes formamidopyrimidine DNA-glycosylase (FPG) and endonuclease III (EndoIII). Both guanylhydrazone derivatives induced DNA damage. Treatment of V79 cells with EndoIII and FPG proteins demonstrated a significant effect of 2,3-DMeB and 3,4-DMeB with respect to oxidized bases. In addition, the derivatives induced a significant increase in the frequency of micronucleated cells at high doses. The antifungal and anti-trypanosomal properties of these guanylhydrazone derivatives were also evaluated, and the obtained results suggest that 2,3-DMeB is more effective than 3,4-DMeB. The biological activity of 2,3-DMeB and 3,4-DMeB may thus be related, at least in part, to their oxidative potential, as well as to their ability to interact with DNA. Considering the previously reported in vitro antitumor activity of guanylhydrazone derivatives in combination with the lack of acute toxicity and the fact that DNA damage is only observed at high doses should render both compounds good candidates for in vivo studies on antitumor activity.
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http://dx.doi.org/10.1016/j.mrgentox.2016.06.001DOI Listing
August 2016

Chemical Characterization and Cytotoxic Activity of Blueberry Extracts (cv. Misty) Cultivated in Brazil.

J Food Sci 2016 Aug 13;81(8):H2076-84. Epub 2016 Jul 13.

Laboratory of Genomics, Proteomics and DNA Repair, Biotechnology Inst, Univ. of Caxias do Sul, RS, Brazil.

Vaccinium corymbosum (L.) varieties cultivation is relatively recent in Brazil, but its production has been intensified given its good adaptability to the Southern Brazil climate. Blueberries are a rich source of phenolic compounds and contain significant levels of anthocyanins, flavonols, chlorogenic acids, and procyanidins, which lead to different biological activities. Chemical identification of skin and whole hydroalcoholic blueberry extracts (ExtSB and ExtWB) revealed the presence of anthocyanins concentrated in the skin and others chemicals compounds as quercetin glycosides, proanthocyanins dimers, citric, and chlorogenic acid in the pulp. Selectivity for tumor cell lines (Hep-2, HeLa, HT-29) using ExtSB and ExtWB extracts was observed through MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay after 24 h of treatment when compared to nontumor cells (MRC-5). Morphological changes and late stages of apoptotic and necrosis process were seen in HT-29 cell line after ExtWB treatment, compared to nontumor cell line MRC-5. These results are in agreement with other studies that indicate the activity of compounds such as anthocyanins and other molecules found in Southern Highbush blueberry variety, attributed to promote beneficial effects on health that may respond as cytotoxic natural agent and contribute to cancer treatment.
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http://dx.doi.org/10.1111/1750-3841.13385DOI Listing
August 2016

Pathways of cardiac toxicity: comparison between chemotherapeutic drugs doxorubicin and mitoxantrone.

Arch Toxicol 2016 Sep 25;90(9):2063-2076. Epub 2016 Jun 25.

Laboratory of Genetic Toxicology, Federal University of Health Sciences of Porto Alegre (UFCSPA), Rua Sarmento Leite, 245, Porto Alegre, RS, Brazil.

Anthracyclines, e.g., doxorubicin (DOX), and anthracenediones, e.g., mitoxantrone (MTX), are drugs used in the chemotherapy of several cancer types, including solid and non-solid malignancies such as breast cancer, leukemia, lymphomas, and sarcomas. Although they are effective in tumor therapy, treatment with these two drugs may lead to side effects such as arrhythmia and heart failure. At the same clinically equivalent dose, MTX causes slightly reduced cardiotoxicity compared with DOX. These drugs interact with iron to generate reactive oxygen species (ROS), target topoisomerase 2 (Top2), and impair mitochondria. These are some of the mechanisms through which these drugs induce late cardiomyopathy. In this review, we compare the cardiotoxicities of these two chemotherapeutic drugs, DOX and MTX. As described here, even though they share similarities in their modes of toxicant action, DOX and MTX seem to differ in a key aspect. DOX is a more redox-interfering drug, while MTX induces energy imbalance. In addition, DOX toxicity can be explained by underlying mechanisms that include targeting of Top2 beta, mitochondrial impairment, and increases in ROS generation. These modes of action have not yet been demonstrated for MTX, and this knowledge gap needs to be filled.
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http://dx.doi.org/10.1007/s00204-016-1759-yDOI Listing
September 2016

Antioxidant defences and haemocyte internalization in Limnoperna fortunei exposed to TiO2 nanoparticles.

Aquat Toxicol 2016 Jul 27;176:190-6. Epub 2016 Apr 27.

Institute of Biotechnology, University of Caxias do Sul (UCS), Rua Francisco Getúlio Vargas 1130, 95070-560 Caxias do Sul, RS, Brazil; Department of Biophysics/Center of Biotechnology, Federal University of Rio Grande do Sul (UFRGS), Av. Bento Gonçalves 9500, Campus do Vale Setor 4, Box 43422, 91501-970 Porto Alegre, RS, Brazil; InnVitro Research and Development, Rua Mariante 180, Sala 902, 90430-180 Porto Alegre, RS, Brazil.

TiO2 nanoparticles (TiO2-NP) have been incorporated into a large range of materials for different applications in the last decades and are very likely to appear in wastewater and effluents, eventually reaching the aquatic environment. Therefore, the assessment of the biological impact of TiO2-NP on aquatic ecosystem is of a major concern. The mussels represent a target group for TiO2-NP toxicity, as they are filter feeders and are capable of bioaccumulating toxic compounds. Furthermore, the exotic organism Limnoperna fortunei, golden mussel, is a freshwater bivalve that has been used in biomonitoring environmental conditions. In this work, the TiO2-NP's ability to interact with haemocytes of golden mussel was assessed by transmission electron microscopy. The enzymatic and non-enzymatic antioxidant defenses were evaluated by superoxide dismutase (Sod) and catalase (Cat) activities and protein sulfhydryl content, which were measured after the golden mussel was exposed to TiO2-NP (1, 5, 10 and 50μgmL(-1)). Results demonstrate that TiO2-NP was internalized by cells, causing alterations in haemocytes membrane. Antioxidant activity of Sod and Cat decreased after 2h TiO2-NP exposure. After 4h exposure, the enzymatic antioxidant activity was restored. Notably, the protein sulfhydryl content decreased after 2h to all the TiO2-NP concentrations and no alterations were observed after 4h of TiO2-NP exposure. These results demonstrate the potential of golden mussel as sentinel organism to TiO2-NP exposure.
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http://dx.doi.org/10.1016/j.aquatox.2016.04.024DOI Listing
July 2016
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