ABSTRACT
The surfactant Tween 80 is widely used in genotoxicity tests in many test systems to dilute hydrophobic substances that are being investigated. In this work, the possible genotoxic effect of Tween 80 was evaluated by chromosomic aberration test in Allium cepa. Temporary treatments were performed, in which the seeds germinated in ultrapure water were kept for 24 and 72 h in the concentrations of 1, 2, 3, 4, 5, 6, 7 e 8 per cent of Tween 80. Methane sulfonate (4x10-4 M) was used as a positive control and ultrapure water as a negative control. The roots were fixed in Carnoy and stained using Feulgen method. The slides were prepared using the common method of gentle squashing and approximately 5000 cells were analyzed to each concentration tested and to controls. The mitotic index, chromosomic aberration index and mutagenicity index did not differ statistically from the negative controls, disclosing absence of citotoxicity, genotoxicity and mutagenicity of Tween 80. Therefore, Tween 80 can be used in genotoxic tests, in temporary treatments, using the A. cepa as test organism.
O surfactante Tween 80 é bastante utilizado em testes de genotoxidade, com diversos sistemas teste, para diluir as substâncias hidrofóbicas a serem investigadas. Neste trabalho, o possível efeito genotóxico desta substância foi avaliado utilizando o teste de aberrações cromossômicas em Allium cepa. Foram realizados os tratamentos temporários, no qual as sementes, germinadas em água ultra-pura, permaneceram por 24 e 72 h, nas concentrações de 1, 2, 3, 4, 5, 6, 7 e 8 por cento de Tween 80. Metil metano sulfanato (4x10-4 M) foi utilizado como controle positivo e água ultra-pura como controle negativo. As raízes foram fixadas em Carnoy e coradas pelo método de Feulgen. As lâminas foram preparadas pelo método de esmagamento suave e aproximadamente 5000 células foram analisadas para cada concentração testada e para os controles. Não foram encontradas diferenças estatisticamente significativas entre as diferentes concentrações e o controle negativo, em relação ao índice mitótico, índice de aberrações e índice de mutagenicidade, o que revela ausência de efeito citotóxico, genotóxico e mutagênico do Tween 80.Desta forma, o Tween 80 pode ser utilizado em testes de genotoxidade, em tratamentos temporários, utilizando oorganismo teste A. cepa.
Subject(s)
Onions , Genotoxicity , Polysorbates , Plant RootsABSTRACT
An aqueous extract of Rhizophora mangle L. bark is used as raw material in pottery making in the State of Espirito Santo, Brazil. This extract presents large quantities of tannins, compounds possessing antioxidant properties. Tannin antioxidant activity, as a plant chemical defense mechanism in the process of stabilizing free radicals, has been an incentive to studies on anti-mutagenicity. The present work aimed to evaluate possible antimutagenic activity of a R. mangle aqueous extract, using the Allium cepa test-system and micronuclear (MN) assay with blockage of cytokinesis in Chinese hamster ovary cells (CHO-K1). The Allium cepa test-system indicated antimutagenic activity against the damage induced by the mutagenic agent methyl methanesulfonate. A reduction in both MN cell frequency and chromosome breaks occurred in both the pre and post-treatment protocols. The MN testing of CHO-K1 cells revealed anti-mutagenic activity of the R. mangle extract against methyl methanesulfonate and doxorubicin in pre, simultaneous and post-treatment protocols. These results suggest the presence of phyto-constituents in the extract presenting demutagenic and bio-antimutagenic activities. Since the chemical constitution of Rhizophora mangle species presents elevated tannin content, it is highly probable that these compounds are the antimutagenic promoters themselves.