Search

Health risk assessment of nanomaterials is an emergent field, genotoxicity being an important endpoint to be tested. Since in vivo studies offer many advantages, such as the study of the bioavailability of nanomaterials to sensitive target cells, we propose Drosophila as a useful model for the study of the toxic and genotoxic risks associated with nanoparticle exposure. In this work we have carried out a genotoxic evaluation of silver nanoparticles in Drosophila by using the wing somatic mutation and recombination test. This test is based on the principle that loss of heterozygosis and the corresponding expression of the suitable recessive markers, multiple wing hairs and flare-3, can lead to the formation of mutant clones in larval cells, which are expressed as mutant spots on the wings of adult flies. Silver nanoparticles were supplied to third instar larvae at concentrations ranging from 0.1-10 mM. The results showed that small but significant increases in the frequency of total spots were observed, thus indicating that silver nanoparticles were able to induce genotoxic activity in the wing spot assay of D. melanogaster, mainly via the induction of somatic recombination. These positive results obtained with silver nanoparticles contrast with the negative findings obtained when silver nitrate was tested. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to assess the adaptive response induced by low doses of ultraviolet-B (UVB, 290-320 nm) radiation in the Drosophila wing spot test. Materials and methods: The adaptive response of Drosophila larvae to UVB light was studied by using a somatic mutation and recombination test (SMART). The SMART system used was the wing spot test, which uses morphological markers of the wing blade. This in vivo test has shown to be very useful to study the induction of genetic damage in somatic cells, measuring loss of heterozygosity (LOH) resulting from gene mutation, mitotic recombination, chromosomal rearrangements or chromosome loss. Results: To determine the induction of adaptive response, two-day-old Drosophila larvae were first irritated with an adaptive dose (58.3 J/m2), followed by different challenge doses (178, 224, 288, 338, and 386 J/m2). When the results obtained in the different challenge doses were compared with those obtained following the application of adaptive plus challenge doses, significant decreases (74.7-80.8%) in a first experiment, and (65.6-78.4%) in a second experiment, were observed in the frequency of mutant spots on the wing blades. Conclusions: Our results show that in Drosophila the adaptive response can be stimulated in vivo by UVB exposure. [ABSTRACT FROM AUTHOR]

The antimutagenic effect of ascorbic acid (vitamin C) was investigated by using the Drosophila wing spot test. In this assay, 3-day-old transheterozygous larvae for the multiple wing hair (mwh, 3-0.3) and flare (flr, 3-38.8) genes were treated with 3 direct acting mutagens: ethyl methanesulfonate (EMS), methyl methanesulfonate (MMS) and N-nitroso N-ethylurea (ENU). The results obtained from 3 reference mutagens were clearly genotoxic in the Drosophila wing somatic mutation and recombination test. The calculated concentration of ascorbic acid as recommended dietary allowance (RDA) did not induce the frequency of the mutant clones recorded. When co-treatment experiments with ascorbic acid were carried out, ascorbic acid was effective in reducing the genotoxicity of the 3 direct acting mutagens. [ABSTRACT FROM AUTHOR]

Highlights: [•] Drosophila was used to determine the genotoxic risk of several nanomaterials. [•] Titanium, zirconium and aluminium nanoparticles, and their ions were tested. [•] Mutation/recombination effects in wing somatic cells were determined. [•] No increases in genetic damage levels were observed in any treatment. [•] Our results contribute to increase the genotoxicity database on nanomaterials. [ABSTRACT FROM AUTHOR]