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Abstract(s)
A implementação de novas legislações com vista a regulamentar a introdução de novos
compostos nos produtos para consumo como os desenvolvidos na indústria cosmética,
introduziu a necessidade de se desenvolverem testes in vitro que substituíssem os clássicos
testes in vivo de modo a ser possível aumentar o número de testes toxicológicos e, ao mesmo
tempo, diminuir o uso de animais em laboratório. Pretende-se construir uma base de dados
acerca dos compostos usados o mais detalhadamente possível, de modo a maximizar a
segurança dos mesmos, abrangendo testes nas mais diferentes áreas da toxicologia. Neste
âmbito, surge em 2004 o projecto ReProTect que pretende desenvolver métodos alternativos
para o estudo da toxicidade reprodutiva. A complexidade do ciclo reprodutivo torna
necessário dividir o seu estudo em partes, desenvolvendo diversos testes alternativos com
endpoints diferentes. Nos últimos anos tem-se colocado em questão a segurança imputada
aos diferentes filtros UV presentes nos protectores solares. O octocrileno é um filtro UV
relativamente recente sendo a informação disponível acerca deste composto, em mamíferos,
muito escassa. O presente trabalho tem como principal objectivo testar o potencial tóxico
desta substância utilizando para isso um dos testes desenvolvidos durante o projecto
ReProTect. O teste de maturação in vitro de oócitos de bovino (bIVM) permite analisar a
influência que o octocrileno pode ter durante o processo de maturação dos oócitos
nomeadamente na conclusão do processo de meiose. O endpoint deste teste reflecte a
concentração de composto a partir da qual 50% dos oócitos são inibidos de concluir a meiose
(EC50) sendo os resultados apresentados em percentagem de oócitos em MII. Foram testadas
cinco concentrações de octocrileno entre 0,195HM-1,560HM. Os resultados obtidos
demonstram uma tendência decrescente de oócitos em MII à medida que se aumenta a
concentração. Apesar de se observar valores de percentagem de MII inferiores a 50% (valor
mínimo obtido:37%), a determinação do valor de EC50 do octocrileno não pôde ser confirmada
devido ao reduzido valor de amostragem. O facto de não existir informações prévias acerca
da potencial toxicidade reprodutiva do octocrileno faz com que se considere que este
trabalho representa um importante contributo na medida em que se identifica a gama onde
provavelmente se situa o valor de EC50 do octocrileno valor que, a confirmar-se, encontra-se
abaixo dos 50HM definidos como concentração de EC50, abaixo da qual todos os compostos são
considerados como positivos no que se refere ao estudo da toxicidade reprodutiva.
The implementation of new legislation to regulate the introduction of new compounds in consumer products such as those developed in the cosmetics industry, has introduced a need to develop in vitro assays that replace the in vivo tests traditionally used in order to be able to increase the number of toxicological test at the same time that reducing the use of laboratory animals. It’s intended to build a database on the compounds used in as much detail as possible in order to maximize data security, comprising testing in different areas of toxicology. In this context, in 2004 was developed the ReProTect project that aims to develop alternative approaches to the study of reproductive toxicity methods. The complexity of the reproductive cycle does not allow the study of their sensitivity to potentially toxic compounds in a global manner, it is necessary divide into parts, and develop several alternative tests with different endpoints. In the last years, several publications had questioned the imputed safety of UF filters present in sunscreens. Octocrylene is a relatively new UV filter witch have very few data reported. There is no information about, among the others, his potential reproductive toxicity. This study aims to test the potential toxicity of this substance using one of the tests developed during the ReProTect project. The in vitro maturation of bovine oocytes test (bIVM) allows to analyze the influence that the octocrylene may have during the process of oocyte maturation particularly at the conclusion of the process of meiosis. The endpoint of the test compound reflects the concentration from which 50% of the oocytes are inhibited from completing meiosis (EC50). The results are presented in % of oocytes that concluded meiosis. Five concentrations of octocrylene between the range of 0,195µM-1,560µM were incorporated during in vitro maturation of bovine oocytes were. The results were observed in visible inverted microscope (400x) and fluorescence (400x). The results showed a downward trend in the % of MII oocytes as the concentration increased. It was possible to observe values under the EC50. A minimum of 37% of MII oocytes was reached. Despite that, the determination of the EC50 value of octocrylene could not be confirmed. It is necessary a larger sample and a greater number of replicates to do it. This study can be an important contribution doing an initial screening of octocrylene concentrations, identifying the possible range of the EC50 value. This takes more importance if we consider that for EC50 under 50µM, the compounds are considered positive to toxicity reproduction. The values tested in this study are far below of 50µM.
The implementation of new legislation to regulate the introduction of new compounds in consumer products such as those developed in the cosmetics industry, has introduced a need to develop in vitro assays that replace the in vivo tests traditionally used in order to be able to increase the number of toxicological test at the same time that reducing the use of laboratory animals. It’s intended to build a database on the compounds used in as much detail as possible in order to maximize data security, comprising testing in different areas of toxicology. In this context, in 2004 was developed the ReProTect project that aims to develop alternative approaches to the study of reproductive toxicity methods. The complexity of the reproductive cycle does not allow the study of their sensitivity to potentially toxic compounds in a global manner, it is necessary divide into parts, and develop several alternative tests with different endpoints. In the last years, several publications had questioned the imputed safety of UF filters present in sunscreens. Octocrylene is a relatively new UV filter witch have very few data reported. There is no information about, among the others, his potential reproductive toxicity. This study aims to test the potential toxicity of this substance using one of the tests developed during the ReProTect project. The in vitro maturation of bovine oocytes test (bIVM) allows to analyze the influence that the octocrylene may have during the process of oocyte maturation particularly at the conclusion of the process of meiosis. The endpoint of the test compound reflects the concentration from which 50% of the oocytes are inhibited from completing meiosis (EC50). The results are presented in % of oocytes that concluded meiosis. Five concentrations of octocrylene between the range of 0,195µM-1,560µM were incorporated during in vitro maturation of bovine oocytes were. The results were observed in visible inverted microscope (400x) and fluorescence (400x). The results showed a downward trend in the % of MII oocytes as the concentration increased. It was possible to observe values under the EC50. A minimum of 37% of MII oocytes was reached. Despite that, the determination of the EC50 value of octocrylene could not be confirmed. It is necessary a larger sample and a greater number of replicates to do it. This study can be an important contribution doing an initial screening of octocrylene concentrations, identifying the possible range of the EC50 value. This takes more importance if we consider that for EC50 under 50µM, the compounds are considered positive to toxicity reproduction. The values tested in this study are far below of 50µM.
Description
Keywords
Bivm Ec50. Octocrileno Oócitos de Bovino Reprotect Testes Alternativos In Vitro Toxicidade Reprodutiva