ANGELICA BUENO BARBEZAN

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Agora exibindo 1 - 4 de 4
  • Artigo IPEN-doc 27057
    Evaluation of cytotoxicity through MTS test of 2-ACBs (2-dDCB AND tDCB) after exposure to hepatic cells
    2019 - BARBEZAN, A.B.; CARVALHO, L.R.; VIEIRA, D.P.; MACHADO-SANTELLI, G.M.; MARTINS, R.; VILLAVICENCIO, A.L.C.H.
    Food irradiation has been approved in more than 60 countries for many applications in a wide variety of foods. 2-Alkylcyclobutanones (2-ACBs) are the only known radiolytic products formed when foods containing fatty acids are irradiated. Despite the importance of food irradiation, the toxicological potential of 2-ACBs in irradiated food is still no fully understood. In this study we investigated the cytotoxic effects of irradiated palmitic and stearic fatty acids byproducts, 2-dDCB and 2-tDCB, in hepatic cell lines (HepG2, BRL3A and HTC). The cytotoxic effects of 2-dDCB and 2-tDCB were evaluated at 100, 300 and 500 μM for 24 and 48 hours and the cell viability was measured using the MTS assay. While no toxicity was observed for 2-tDCB in all cells for all tested conditions, 2-dDCB was found to be toxic to BRL3A cells (at 100 μM after 48 hours) and HTC cells (at 24 hours in all tested concentrations). HepG2 cells on the other hand, were found to be resistant to 2-dDCB-induced toxicity. Overall our data shows that the byproduct 2-tDCB is not toxic for hepatic cells while 2-dDCB can be used has a potential marker for food irradiation-induced toxicity.
  • Artigo IPEN-doc 27906
    In vivo genotoxicity of 2-alkylcyclobutanones in liver cells from rats fed with irradiated cocoa butter using flow cytometry
    2021 - MARTINS, R.; VIEIRA, D.P.; CARVALHO, L.R.; BARBEZAN, A.B.; VILLAVICENCIO, A.L.C.H.
    Food irradiation proves to be an effective technique of eliminating some pathogens from food and this has gained significant attention to its potential for food safety. Since 1990, studies on the toxicological safety of 2-Alkylcyclobutanones have been conducted extensively. 2-Alkylcyclobutanones are unique radiolytic products generated by the radiation-induced breakage of triglycerides in food, 2-dodecylcyclobutanone (2-dDCB) and 2-tetradecylcyclobutanone (2-tDCB) are the predominant compounds detected . Despite studies showing non-genotoxicity of 2-ACBs (2-Alkylcyclobutanones), the results are conflicting and therefore we continue the studies in order to confirm the compounds are safety for human health. In vivo micronucleus test were performed to verify the 2-ACBs genotoxic effects in hepatic cells using flow cytometry. We used cocoa butter irradiated with 20 kGy. A group with animals was treated with daily intake of irradiated cocoa butter, synthesized 2-dDCB and 2-tDCB for one month. Hepatic cells were selected for genotoxicity analysis due to the liver importance in the compounds metabolization. The improvement of the analytical techniques is important for the research future since the irradiation process is already consolidated. The results confirmed the safety of the food irradiation process, as they did not indicate the genotoxic potential of the samples.
  • Artigo IPEN-doc 25774
    Flow cytometry based micronucleus assay for evaluation of genotoxic potential of 2-ACBs in hepatic cells HepG2
    2019 - BARBEZAN, ANGELICA B.; SANTOS, CARLA J.B.; CARVALHO, LUMA R.; VIEIRA, DANIEL P.; SANTELLI, GLAUCIA M.M.; VILLAVICENCIO, ANNA L.C.H.
    Food irradiation is approved for use in more than 60 countries for applications and purposes in a wide variety of foods, being an effective and safe method for preservation and long-term storage. 2- Alkylcyclobutanones (2-ACBs) are the only known radiolytic products generated from foods that contain fatty acids (Triglycerides) when irradiated. The acids analyzed in this study are palmitic and stearic, which when irradiated form 2-Dodecylcyclobutanones (2-dDCB) and 2-Tetradecylcyclobutanone (2-tDCB). Part of the 2-ACBs ingested is excreted through feces and part is deposited in adipose tissues. In vitro studies so far have been only in colon cells. The work used a human hepatoma cell line (HepG2) since the accumulation of fat in this organ is quite common. Micronucleus test was selected to evaluate possible genotoxic effects of 2-dDCB and 2-tDCB compounds when exposed to high concentrations (447, 1422 and 2235 μM) for 4 and 24 hours. Tests were performed in quadriplicates using flow cytometric analysis. None detectable genotoxic damage was observed after 4 hours of exposure to the compounds, and cytotoxic effects were only significant at the highest concentration (2235 μM) of 2-dDCB. After 24 hours of exposure, slight genotoxic damage was observed at all concentrations evaluated, and cytotoxic effects were only present when exposed to compound 2-tDCB. Although there is a genotoxic and cytotoxic effect in some of the situations tested, the two compounds predominantly induced proliferation reduction effects of this hepatic tumor cell line.
  • Tese IPEN-doc 24208
    Estudos in vitro da genotoxicidade e citotoxicidade em células hepáticas da formação de 2-alcilciclobutanonas resultantes da irradiação de alimentos que contenham gordura
    2017 - BARBEZAN, ANGÉLICA B.
    A irradiação de alimentos já foi aprovada e vem sendo utilizada em diversos países para aplicações e finalidades de uma ampla variedade de alimentos. Seus benefícios abrangem o aumento do prazo de validade, melhoria de higiene dos alimentos e consequentemente menor deterioração e perdas se comparado com alimentos que não sofrem radiação. Além disto, os alimentos após irradiados apresentam-se seguros em termos nutritivos e de redução de patógenos. Porém, alimentos que contem de médio a alto teor de gordura induzem a formação de um subproduto denominado 2-Alcilciclobutanonas, a qual sabemos que parte destes compostos ingeridos são normalmente excretados através das fezes, porém parte permanece depositada nos tecidos adiposos. Trabalhos realizados com estes compostos anteriormente apresentaram efeitos citotóxicos e genotóxicos em células de cólon. Desta forma, o objetivo do presente trabalho foi investigar os efeitos citotóxicos realizados em testes de viabilidade celular, testes genotóxicos em micronúcleo e testes mutagênicos com a técnica de Ames em condições experimentais in vitro dos compostos 2-dDCB e 2-tDCB. Para isso, o fígado foi o órgão de escolha para avaliar os possíveis efeitos destes compostos, uma vez que este órgão é geralmente acometido pelo acumulo de gordura. Foram utilizadas três linhagens hepáticas: HepG2, BRL3A e HTC. A análise dos resultados da viabilidade celular, revelou que as 2-dDCBs apresentaram discreto efeito citotóxico na concentração de 500 μM e as 2-tDCBs apresentaram danos baixos a partir de 100 μM e maiores em 500 μM, mostrando ser dose dependentes. Nos resultados de mutagenicidade, os compostos não apresentaram quaisquer efeitos mutagênicos nas concentrações e doses utilizadas, detectados pelo teste de Ames. Por fim, o ensaio de micronúcleo correspondeu às expectativas não demonstrando efeitos genotóxicos na linhagem, doses e tempos testados. Com base nos resultados atingidos, as 2 ACBs podem ser consumidas com relativa segurança, sob a ótica de possíveis efeitos mutagênicos e genotóxicos nas concentrações avaliadas.