Analysis of the in vivo nitrosation capacity of the larvae used in the wing somatic mutation and recombination test of Drosophila melanogaster

Multi-Endpoint Toxicological Assessment of Chrysin Loaded Oil-in-Water Emulsion System in Different Biological Models

Chrysin is hypothesized to possess the ability to prevent different illnesses, such as diabetes, cancer, and neurodegenerative disorders. Nonetheless, chrysin has a low solubility under physiological conditions, resulting in limited bioavailability. In a previous study, we utilized an oil-in-water emulsion system (chrysin-ES or chrysin-NE) to encapsulate chrysin, thereby increasing its bioaccessibility and preserving its antioxidant and anti-Alzheimer's properties. To promote the chrysin-ES as a supplementary and functional food, it was obligatory to carry out a safety assessment. Cytotoxicity testing showed that chrysin-ES was harmless, with no killing effect on 3T3-L1 (adipocytes), RAW 264.7 (macrophages), HEK293 (kidney cells), and LX-2 (hepatic stellate cells). The acute toxicity evaluation demonstrated that the 50% lethal dose (LD50) for chrysin-ES was greater than 2000 mg/kg BW. Genotoxicity assessments found that chrysin-ES did not induce DNA mutations in vitro or in vivo. Furthermore, chrysin and chrysin-ES exhibited anti-mutagenic properties against PhIP-induced and IQ-induced mutagenesis in the Ames test, while they inhibited urethane-, ethyl methanesulfonate-, mitomycin C-, and N-nitrosomethylurea-mediated mutations in Drosophila. The present study illustrates the safety and anti-genotoxicity properties of chrysin-ES, allowing for the further development of chrysin-based food supplements and nutraceuticals.

Human Hazard Assessment Using Drosophila Wing Spot Test as an Alternative In Vivo Model for Genotoxicity Testing-A Review

Genomic instability, one of cancer's hallmarks, is induced by genotoxins from endogenous and exogenous sources, including reactive oxygen species (ROS), diet, and environmental pollutants. A sensitive in vivo genotoxicity test is required for the identification of human hazards to reduce the potential health risk. The somatic mutation and recombination test (SMART) or wing spot test is a genotoxicity assay involving Drosophila melanogaster (fruit fly) as a classical, alternative human model. This review describes the principle of the SMART assay in conjunction with its advantages and disadvantages and discusses applications of the assay covering all segments of health-related industries, including food, dietary supplements, drug industries, pesticides, and herbicides, as well as nanoparticles. Chemopreventive strategies are outlined as a global health trend for the anti-genotoxicity of interesting herbal extract compounds determined by SMART assay. The successful application of Drosophila for high-throughput screening of mutagens is also discussed as a future perspective.

Genotoxicity assessment of four novel quinazoline-derived trypanocidal agents in the Drosophila wing somatic mutation and recombination test

Chagas disease, caused by the protozoan Trypanosoma cruzi, has increased in the world due to migration, travelling and climate change; at present, the principal problem is that common trypanocidal agents have resulted in toxic or inconvenient side effects. We tested for genotoxicity in the standard (ST) and high bioactivation (HB) crosses of Drosophila wing somatic mutation and recombination test, four novel trypanocidal agents derived from 2, 4, 6-triaminquinazoline (TAQ): 2,4-diamino-6 nitro-1,3 diazonaftalene (S-1QN2-1), 2,4-diacetamino-6-amino 1,3 diazonaftalene (D-1), N6-(4,methoxybenzyl)quinazoline-2,4,6-triamine (GHPM) and N6-[4-(trifluoromethoxy)benzyl]quinazoline-2,4,6-triamine (GHPMF) at 1.9, 3.9, 7.9 and 15 µM, respectively. Also, high-pressure liquid chromatography (HPLC) analysis was run to determine the remanence of either drug in flare, and Oregon R(R)-flare flies emerged from treated larvae. S-1QN2-1 showed genotoxicity only in the ST cross, increasing the small, large and total spot frequencies at all concentrations and twin spots only at 1.9 µM; D-1 and GHPM showed significant increments of large spots only at 15 µM in the ST cross; GHPMF was not genotoxic at any concentration or either cross. In the mwh clones accumulated distribution frequencies analysis, associated with disrupted cell division, S-1QN2-1 caused alterations in the ST cross at all concentrations but only at 15 µM in the HB cross; D-1 caused alterations at 3.9, 7.9 and 15 µM in the ST cross and at 1.9 and 15 µM in the HB cross; GHPM caused alterations at 7.9 and 15 µM in the ST cross and also at 1.9, 3.9 and 7.9 µM in the HB cross; GHPMF caused those alterations at all concentrations in the ST cross and at 1.9, 3.9 and 7.9 µM in the HB cross. The HPLC results indicated no traces of either agent in the flare and Oregon R(R)-flare flies. We conclude that S-1QN2-1 is clearly genotoxic, D-1 and GHPM have an unclear genotoxicity and GHPMF was not genotoxic; all quinazoline derivatives disrupted cell division. GHPMF is a good candidate to be tested in other genotoxicity and cytotoxic bioassays. The differences in the genotoxic activity of these trypanocidal agents are correlated with differences in their chemical structure.

Modulating effect of losartan potassium on the mutagenicity and recombinogenicity of doxorubicin in somatic cells of Drosophila melanogaster

Losartan potassium is an antihypertensive drug in the angiotensin II receptor antagonist (ARA) class. Some studies claim that, in addition to regulating blood pressure, this class of drug has anticancer properties. The objective of this study was to evaluate the genotoxic and antigenotoxic potential of losartan potassium using the SMART (Somatic Mutation and Recombination Test) assay on the somatic cells of Drosophila melanogaster, as well as the possible modulating effects of this drug, when associated with doxorubicin (DXR). Third instar larvae, descendents of standard and high bioactivation (ST and HB) crosses, were chronically treated with different concentrations of losartan potassium (0.25; 0.5; 1; 2; and 4 mM) alone or in association (co-treatment) with doxorubicin (DXR 0.125 mg/mL). The results showed an absence of a mutagenic effect of losartan potassium. In the co-treatment of losartan with DXR, the results showed that losartan is capable of reducing the number of mutant spots induced by DXR without altering the recombinogenic effect of the chemotherapeutic agent. Antiproliferative action appears to be the main mechanism involved in reducing the frequency of mutant spots and consequent modulation of alterations induced by DXR, although this parameter has not been directly assessed in this study.

Genotoxicity testing of four food preservatives and their combinations in the Drosophila wing spot test

In this study, four food preservatives (sodium nitrate, sodium nitrite, potassium nitrate and potassium nitrite) and there five combinations at a concentration of 25mM have been evaluated for genotoxicity in the somatic mutation and recombination test (SMART) of Drosophila melanogaster. Three-day-old larvae trans-heterozygous including two linked recessive wing hair mutations (multiple wing hairs and flare) were fed at different concentrations of the test compounds (25, 50, 75 and 100mM) in standard Drosophila Instant Medium. Wings of the emerging adult flies were scored for the presence of spots of mutant cells, which can result from either somatic mutation or mitotic recombination. Also lethal doses of food preservatives used were determined in the experiments. A positive correlation was observed between total mutations and the number of wings having mutation. In addition, the observed mutations in each wing were classified according to the size and type of the mutation. For the evaluation of genotoxic effects, the frequencies of spots per wing in the treated series were compared to the control group, which is distilled water. Chemicals used were ranked as sodium nitrite, potassium nitrite, sodium nitrate and potassium nitrate according to their genotoxic and toxic effects. Moreover, the genotoxic and toxic effects produced by the combined treatments were considerably increased, especially when the four chemicals were mixed. The present study shows that correct administration of food preservatives/additives may have a significant effect on human health.

Evaluation of genotoxicity of captan, maneb and zineb in the wing spot test of Drosophila melanogaster: role of nitrosation

The wing spot test in Drosophila melanogaster is a suitable system for the analysis of genotoxic activity of compounds that need metabolic transformation to render them active. We have analysed the genotoxicity of three fungicides for which it was reported that the metabolic processes taking place in vivo may determine their activity. The compounds analysed are captan, maneb, zineb and ethylenethiourea (ETU) (a metabolic derivative of ethylenebisdithiocarbamates like maneb and zineb). We have also evaluated the ability of ETU to form genotoxic derivatives in vivo analysing this compound in combined treatments with sodium nitrite. Both standard and high bioactivation NORR strains have been used. Captan, usually considered a mutagen in vitro but a non-mutagen in vivo, gave negative results in the wing spot test with both crosses. Positive results were obtained for maneb in the standard cross and for ETU in both the standard and the high bioactivation cross. The genotoxicities of maneb and ETU were higher when treatments were made on media in which nitrosation is favoured. A low absorption of the fungicide and an inefficient availability of the compound in the target may explain negative results obtained with zineb in both crosses. The results obtained in this study with the wing spot test demonstrate once again the suitability of this in vivo assay, in which absorption, distribution and metabolism processes take place, for the evaluation of genotoxicity of compounds to which humans are exposed.

Antimutagenic effect of one variety of green pepper (Capsicum spp.) and its possible interference with the nitrosation process

It is known that the poblano green pepper, a significant component in the Mexican diet, contains certain natural compounds such as chlorophyll, beta-carotene, and vitamins, which have antimutagenic and/or anticarcinogenic properties. Using the somatic mutation and recombination test in wing cells of Drosophila melanogaster, an extract of the poblano pepper (Capsicum spp.) was evaluated to determine its antimutagenic effect against the nitrosation process, simulating the process occurring in the human stomach caused by known food additives. Larvae of 72h old D. melanogaster of standard (ST) and high bioactivation (HB) crosses were exposed in a simultaneous, chronic treatment with the juice expressed from the crushed, whole, fresh pepper fruit, plus the mixture of 20mM methyl urea (MU) and sodium nitrite (SN), mixed with the animals' food. Three doses of pepper juice (12.5, 25, and 50%) were used. The background mutation rate given as spots per wing was 0.36 and 0.48 for ST and HB, respectively. Mutation frequencies produced by the MU and SN mixture was 1.73 (ST) and 26.46 (HB) mutations per wing. The poblano juice decreased the above rates between 40 and 80%, respectively. The experiments suggest that some compounds present in the green pepper may cause this antimutagenic effect by interfering with the nitrosation process. The role of the extract and one of its components, such as vitamin C, in the nitrosation process will be discussed.

Antimutagenic profile of three antioxidants in the Ames assay and the Drosophila wing spot test

Antimutagens and anticarcinogens are known to play an important role in combating the action of factors involved in the etiology of cancer. It is expected that inhibitors of mutagenesis also act as inhibitors of carcinogenesis. In the present study, two short-term genotoxicity assays, namely the Ames assay and the Drosophila wing spot test, have been selected for examining the antimutagenic potential of three antioxidants. For this purpose, a promutagen aflatoxin B(1) (AFB(1)) was chosen as a positive mutagen against which antimutagenic potential of alpha-tocopherol (Vit. E), caffeic acid (CA) and glutathione (GSH) was assessed. Vit. E did not exert any antimutagenic response while CA and GSH were effective in reducing the mutational events induced by AFB(1).