Optimal experimental design and sample size for the statistical evaluation of data from somatic mutation and recombination tests (SMART) in Drosophila

Genotoxicity responses of single and mixed exposure to heavy metals (cadmium, silver, and copper) as environmental pollutants in Drosophila melanogaster

Heavy metals are now persistently present in living things' environments, in addition to their potential toxicity. Therefore, the aim of this study was to utilize D. melanogaster to determine the biological effects induced by different heavy metals including cadmium chloride (CdCl2), copper (II) sulfate pentahydrate (CuSO 4.5 H2O), and silver nitrate (AgNO3). In vivo experiments were conducted utilizing three low and environmentally relevant concentrations from 0.01 to 0.5 mM under single and combined exposure scenarios on D. melanogaster larvae. The endpoints measured included viability, reactive oxygen species (ROS) generation and genotoxic effects using Comet assay and the wing-spot test. Results indicated that tested heavy metals were not toxic in the egg-to adult viability. However, combined exposure (CdCl2+AgNO3 and CdCl2+AgNO3+CuSO 4.5 H2O) resulted in significant genotoxic and unfavorable consequences, as well as antagonistic and/or synergistic effects on oxidative damage and genetic damage.

Protective effects of resveratrol against genotoxicity induced by nano and bulk hydroxyapatite in Drosophila melanogaster

Hydroxyapatite (HAp) is a naturally occurring calcium phosphate mineral predominantly used for its biocompatibility in a number of areas such as bone grafting, prosthesis coating in dentistry, and targeted drug delivery. Since the nano form of HAp (nHAp) has gained popularity attributed to a re-mineralizing effect in dental repair procedures, concerns have been raised over safety and biocompatibility of these nanoparticles (NP). This study, therefore, aimed to (1) investigate mechanisms of potential genotoxicity and enhanced generation of reactive oxygen species (ROS) initiated by bulk and nano forms of HAp and (2) test in vivo whether resveratrol, a type of natural phenol, might mitigate the extent of potential DNA damage. The size of nHAp was determined to be 192.13 ± 9.91 nm after dispersion using transmission electron microscopy (TEM). Drosophila melanogaster was employed as a model organism to determine the genotoxic potential and adverse effects of HAp by use of (comet assay), mutagenic and recombinogenic activity (wing spot test), and ROS-mediated damage. Drosophila wing-spot tests demonstrated that exposure to nontoxic bulk and nHAp concentrations (1, 2.5, 5 or 10 mM) produced no significant recombination effects or mutagenicity. However, bulk and nHAp at certain doses (2.5, 5 or 10 mM) induced genotoxicity in hemocytes and enhanced ROS production. Resveratrol was found to ameliorate the genotoxic effects induced by bulk HAp and nHAp in comet assay. Data demonstrate that treatment with nano and bulk Hap-induced DNA damage and increased ROS generation D. melanogaster which was alleviated by treatment with resveratrol.

Hazard Assessment of the Effects of Acute and Chronic Exposure to Permethrin, Copper Hydroxide, Acephate, and Validamycin Nanopesticides on the Physiology of Drosophila: Novel Insights into the Cellular Internalization and Biological Effects

New insights into the interactions between nanopesticides and edible plants are required in order to elucidate their impacts on human health and agriculture. Nanopesticides include formulations consisting of organic/inorganic nanoparticles. Drosophila melanogaster has become a powerful model in genetic research thanks to its genetic similarity to mammals. This project mainly aimed to generate new evidence for the toxic/genotoxic properties of different nanopesticides (a nanoemulsion (permethrin nanopesticides, 20 ± 5 nm), an inorganic nanoparticle as an active ingredient (copper(II) hydroxide [Cu(OH)₂] nanopesticides, 15 ± 6 nm), a polymer-based nanopesticide (acephate nanopesticides, 55 ± 25 nm), and an inorganic nanoparticle associated with an organic active ingredient (validamycin nanopesticides, 1177 ± 220 nm)) and their microparticulate forms (i.e., permethrin, copper(II) sulfate pentahydrate (CuSO₄·5H₂O), acephate, and validamycin) widely used against agricultural pests, while also showing the merits of using Drosophila—a non-target in vivo eukaryotic model organism—in nanogenotoxicology studies. Significant biological effects were noted at the highest doses of permethrin (0.06 and 0.1 mM), permethrin nanopesticides (1 and 2.5 mM), CuSO₄·5H₂O (1 and 5 mM), acephate and acephate nanopesticides (1 and 5 mM, respectively), and validamycin and validamycin nanopesticides (1 and 2.5 mM, respectively). The results demonstrating the toxic/genotoxic potential of these nanopesticides through their impact on cellular internalization and gene expression represent significant contributions to future nanogenotoxicology studies.

Exposure to boron trioxide nanoparticles and ions cause oxidative stress, DNA damage, and phenotypic alterations in Drosophila melanogaster as an in vivo model

Boron trioxide nanoparticles (B₂ O₃ NPs) have recently been widely used in a range of applications including electronic device technologies, acousto-optic apparatus fields and as nanopowder for the production of special glasses. We propose Drosophila melanogaster as a useful in vivo model system to study the genotoxic risks associated with NP exposure. In this study we have conducted a genotoxic evaluation of B₂ O₃ NPs (size average 55.52 ± 1.41 nm) and its ionic form in D. melanogaster. B₂ O₃ NPs were supplied to third instar larvae at concentrations ranging from 0.1-10 mM. Toxicity, intracellular oxidative stress (reactive oxygen species, ROS), phenotypic alterations, genotoxic effect (via the wing somatic mutation and recombination test (SMART), and DNA damage (via Comet assay) were the end-points evaluated. B₂ O₃ NPs did not cause any mutagenic/recombinogenic effects in all tested non-toxic concentrations in Drosophila SMART. Negative data were also obtained with the ionic form. Exposure to B₂ O₃ NPs and its ionic form (at two highest concentrations, 2.5 and 5 mM) was found to induce DNA damage in Comet assay. Additionally, ROS induction in hemocytes and phenotypic alterations were determined in the mouths and legs of Drosophila. This study is the first study reporting genotoxicity data in the somatic cells of Drosophila larvae, emphasizing the importance of D. melanogaster as a model organism in investigating the different biological effects in a concentration dependent manner caused by B₂ O₃ NPs and its ionic form. The obtained in vivo results contribute to improvement the genotoxicity database on the B₂ O₃ NPs.

In vivo effects of 1,4-dioxane on genotoxic parameters and behavioral alterations in Drosophila melanogaster

1,4-Dioxane (DXN) is used as solvent in different consumer products including cosmetics, paints, surfactants, and waxes. In addition, DXN is released as an unwanted contaminating by-product as a result of some reactions including ethoxylation of alcohols, which occurs with in personal care products. Consequently, DXN pollution was detected in drinking water and is considered as an environmental problem. At present, the genotoxicity effects attributed to DXN are controversial. The present study using an in vivo model organism Drosophila melanogaster aimed to determine the toxic/genotoxic, mutagenic/recombinogenic, oxidative damage as evidenced by ROS production, phenotypic alterations as well as behavioral and developmental alterations that are closely related to neuronal functions. Data demonstrated that nontoxic DXN concentration (0.1, 0.25, 0.5, or 1%) induced mutagenic (1%) and recombinogenic (0.1, 0.25, or 0.5%) effects in wing spot test and genotoxicity in hemocytes using comet assay. The nontoxic concentrations of DXN (0.1, 0.25, 0.5, or 1%) significantly increased oxidative stress, climbing behavior, thermal sensivity and abnormal phenotypic alterations. Our findings show that in contrast to in vitro exposure, DXN using an in vivo model Drosophila melanogaster this compound exerts toxic and genotoxic effects. Data suggest that additional studies using other in vivo models are thus warranted.

Licania rigida leaf extract: Protective effect on oxidative stress, associated with cytotoxic, mutagenic and preclinical aspects

Brazilian plant biodiversity is a rich alternative source of bioactive compounds since plant-derived extracts and/or their secondary metabolites exhibit potential properties to treat several diseases. In this context, Licania rigida Benth (Chrysobalanaceae Family), a large evergreen tree distributed in Brazilian semi-arid regions, deserves attention for its widespread use in popular medicine, although its biological properties are still poorly studied. The aim of this study was to examine (1) acute and sub-chronic oral toxicity at 2000 mg/kg dose; (2) in vitro cytotoxicity at 0.1; 1; 10; 100 or 1000 µg/ml; (3) in vivo mutagenicity at 5, 10 or 20 mg/ml, and (4) potential antioxidant protective effect of L. rigida aqueous leaf extract of (AELr). No marked apparent toxic and genotoxic effects were observed using in vitro and in vivo assays after in vitro treatment of Chinese hamster ovary cell line (CHO-K1) with AELr or in vivo exposure of Wistar rats and Drosophila melanogaster to different extract concentrations. Concerning the antioxidant effect, the extract exhibited a protective effect by decreasing lipid peroxidation as determined by malondialdehyde levels. No significant changes were observed for glutathione (GSH) levels and activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx). Data demonstrate the beneficial potential of AELr to be employed for therapeutic purposes. However, further studies are required to validate the pharmacological application of this plant extract to develop as a phytotherapeutic formulation.

Publication trends of somatic mutation and recombination tests research: a bibliometric analysis (1984‒2020)

Human exposure to pollutants has been on the rise. Thus, researchers have been focused on understanding the effect of these compounds on human health, especially on the genetic information by using various tests, among them the somatic mutation and recombination tests (SMARTs). It is a sensitive and accurate method applicable to genotoxicity analysis. Here, a comprehensive bibliometric analysis of SMART assays in genotoxicity studies was performed to assess publication trends of this field. Data were extracted from the Web of Science database and analyzed by the bibliometric tools HistCite, Biblioshiny (RStudio), VOSViewer, and CiteSpace. Results have shown an increase in the last 10 years in terms of publication. A total of 392 records were published in 96 sources mainly from Brazil, Spain, and Turkey. Research collaboration networks between countries and authors were performed. Based on document co-citation, five large research clusters were identified and analyzed. The youngest research frontier emphasized on nanoparticles. With this study, how research trends evolve over years was demonstrated. Thus, international collaboration could be enhanced, and a promising field could be developed.

Toxicological and Nutraceutical Screening Assays of Some Artificial Sweeteners

Artificial sweeteners are food additives worldwide used instead of fructose or glucose in many diet beverages. Furthermore, diet beverages intake has been increasing every year. Thus, some food agencies should regulate it based on toxicological studies. Debates and controversial results are demonstrated, and authority can revise its decision on the basis of new data reporting toxicological effects since cyclamate has been forbidden in some countries. Therefore, the aim of this study was to report new data about the toxicity of acesulfame-k, aspartame, and cyclamate, which are useful for authority agencies, determining the toxic potential and nutraceutical capabilities of these compounds. The toxicity, antitoxicity, genotoxicity, antigenotoxicity, and life expectancy assays were carried out in Drosophila as an in vivo model. In addition, in vitro HL-60 line cell was used to evaluate the chemopreventive activity determining the cytotoxic effect and the capability of producing DNA damage due to internucleosomal fragmentation or DNA strand breaks. Furthermore, the methylated status of these cancer cells treated with the tested compounds was assayed as a cancer therapy. Our results demonstrated that all tested compounds were neither toxic nor genotoxic, whereas these compounds resulted in antigenotoxic and cytotoxic substances, except for cyclamate. Aspartame showed antitoxic effects in Drosophila. All tested compounds decreased the quality of life of this in vivo organism model. Acesulfame-k, aspartame, and cyclamate induced DNA damage in the HL-60 cell line in the comet assay, and acesulfame-k generally increased the methylation status. In conclusion, all tested artificial sweeteners were safe compounds at assayed concentrations since toxicity and genotoxicity were not significantly induced in flies. Moreover, Aspartame and Cyclamate showed protective activity against a genotoxin in Drosophila Regarding nutraceutical potential, acesulfame-k and aspartame could be demonstrated to be chemopreventive due to the cytotoxicity activity shown by these compounds. According to DNA fragmentation and comet assays, a necrotic way could be the main mechanism of death cells induced by acesulfame-k and aspartame. Finally, Acesulfame-K hypermethylated repetitive elements, which are hypomethylated in cancer cells resulting in a benefit to humans.

Safety and Protective Activities of Manufactured Alcohol-Free Beers

Nowadays, a general interest in improving health in order to achieve better conditions of life is increasing. Diet is a complex factor affecting health conditions. We analysed the biological activities of three types of alcohol-free lager beer (a blond, a pale-blond and a stout beer) as well as epicatechin gallate (ECG) as one of their most abundant phenols with the aim of revealing them as nutraceuticals. For that purpose, we carried out safety and protective assays of the tested substances in the well-known Drosophila melanogaster animal model. Moreover, chemoprevention studies on human leukaemia cells (HL-60) in an in vitro model were carried out to evaluate the viability and genomic damage potential of the studied compounds on the tumour cell line. Results suggest the safety properties of all compounds, although pale-blond and stout beer only showed genotoxic activity at the lowest concentrations assayed. Moreover, alcohol-free beers and phenols were able to protect against H2O2 oxidative damage as well as to induce an increase in longevity with an improvement of the quality of life in the in vivo animal model assayed. Promising results were obtained with the alcohol-free beers and ECG in the in vitro assays with human leukaemia cells as they inhibited the tumour cells’ growth, induced DNA damage and modified the methylation status of such a cancer cell line. To sum up, alcohol-free beers should be of interest not only because of their reduced calories and isotonic properties but because they can be recognised as nutraceutical substances.

Role of Glucosinolates in the Nutraceutical Potential of Selected Cultivars of Brassica rapa

Brassica rapa L. subsp. rapa (turnip greens), a traditionally consumed vegetable, is well-known due to its high content of glucosinolates, which are secondary metabolites with a positive biological activity for human health. Our hypothesis has been based on the relation between B. rapa glucosinolate content and its healthy properties, and our aim is to establish guidelines for safe B. rapa vegetable consumption. Three B. rapa cultivars (143N5, 143N7 and 163N7) have been characterized by HPLC analysis of purified extracts from leaf samples in order to determine their glucosinolate content and to relate this content to beneficial effects on DNA protection, lifespan extension and chemoprevention. In order to ascertain the heath properties in vitro and in vivo, toxicity activities were assayed in the Drosophila melanogaster and leukaemia cell models; genomic safety was also assessed in both models using genotoxicity, fragmentation and comet assay. The Drosophila model has also been used to study the antioxidative activity and the longevity induction. Our results showed a relationship between B. rapa glucosinolate content and its safety and benefices in its consumption. Gluconapin, the main B. rapa glucosinolate, was directly related with these wholesome effects. The relevant conclusion in the present research is focused on B. rapa cultivar 163N7 due to its high gluconapin content and low progoitrin content, which exert anti-cancer and DNA protection properties and could be recommended as being safe and healthy for human consumption.

Modulating effect of DL-kavain on the mutagenicity and carcinogenicity induced by doxorubicin in Drosophila melanogaster

Kavain, kavalactone, present in Piper methysticum exhibits anticonvulsive, analgesic, anxiolytic, antiepileptic, antithrombotic, anti-inflammatory and antioxidant properties. Given its importance, the aim of the present study was to assess (1) the mutagenic and carcinogenicity of kavain administered alone and (2) the antimutagenic and anticarcinogenic potential when administered simultaneously with the chemotherapeutic drug doxorubicin (DXR) using the Somatic Mutation and Recombination Test (SMART) and Epithelial Tumor Test (ETT) using Drosophila melanogaster as a model system. Third-stage larvae from a standard (ST) and high metabolic bioactivation (HB) crosses were treated with different kavain concentrations (32, 64 or 128 μg/ml), alone or in conjunction with DXR (0.125 mg/ml). In ST descendants, kavain produced no significant mutagenic or recombinogenic effects. In the HB cross, mutagenic activity was observed at kavain concentrations of 64 and 128 μg/ml. In the DXR and kavain co-treatment, a modulating effect of the DXR-mediated mutagenic response dependent upon the concentration was detected in both crosses. In ETT, no marked carcinogenic or anticarcinogenic activity was noted for kavain. However, when kavain was combined with DXR synergistic induction of tumors by the chemotherapeutic drug occurred indicating that kavain enhanced the carcinogenic action of DXR.

Phytochemical prospecting, isolation, and protective effect of the ethanolic extract of the leaves of Jatropha mollissima (Pohl) Baill

Jatropha mollissima is used in folk medicine as antimicrobial, antiparasitic, and larvicidal. However, few toxicogenetic studies have been carried out. Therefore, the aim of this study was to determine the phytochemical profile of ethanolic leaf extract of J. mollissima (EEJM) as well as potential cytotoxic, mutagenic, and antimutagenic properties. The EEJM was subjected to successive fractionation for the isolation of secondary metabolites, and five concentrations (0.01; 0.1; 1; 10 and 100 mg/ml) of extract were investigated using Allium cepa assay and the Somatic Mutation and Recombination (SMART) test. The mitotic index and % damage reduction were analyzed for A. cepa and the frequency of mutant hair for SMART. The presence of coumarins, alkaloids, flavonoids, saponins, and tannins was detected, while spinasterol and n-triacontane were the isolates identified for the first time for this species. EEJM did not exhibit cytotoxicity and was not mutagenic at 1 or 10 mg/ml using A. cepa and all concentrations of EEJM were not mutagenic in the SMART test. A cytoprotective effect was found at all concentrations. At 1 or 10 mg/ml EEJM exhibited antimutagenicity in A. cepa. In SMART, the protective effect was observed at 0.1 to 100 mg/ml EEJM. Our results demonstrate the important chemopreventive activity of EEJM, a desired quality in the search for natural anticarcinogenic compounds.

Mechanisms and biological impacts of graphene and multi-walled carbon nanotubes on Drosophila melanogaster: Oxidative stress, genotoxic damage, phenotypic variations, locomotor behavior, parasitoid resistance, and cellular immune response

The use of graphene and multi-walled carbon nanotubes (MWCNTs) has now become rather common in medical applications as well as several other areas thanks to their useful physicochemical properties. While in vitro testing offers some potential, in vivo research into toxic effects of graphene and MWCNTs could yield much more reliable data. Drosophila melanogaster has recently gained significant popularity as a dynamic eukaryotic model in examining toxicity, genotoxicity, and biological effects of exposure to nanomaterials, including oxidative stress, cellular immune response against two strains (NSRef and G486) of parasitoid wasp (Leptopilina boulardi), phenotypic variations, and locomotor behavior risks. D. melanogaster was used as a model organism in our study to identify the potential risks of exposure to graphene (thickness: 2-18 nm) and MWCNTs in different properties (as pure [OD: 10-20 nm short], modified by amide [NH₂ ] [OD: 7-13 nm length: 55 μm], and modified by carboxyl [COOH] [OD: 30-50 nm and length: 0.5-2 μm]) at concentrations ranging from 0.1 to 250 μg/ml. Significant effects were observed at two high doses (100 and 250 μg/ml) of graphene or MWCNTs. This is the first study to report findings of cellular immune response against hematopoiesis and parasitoids, nanogenotoxicity, phenotypic variations, and locomotor behavior in D. melanogaster.

Adverse biological effects of ingested polystyrene microplastics using Drosophila melanogaster as a model in vivo organism

The abundant presence and extensive use of polystyrene microplastics (PSMPs) has recently become a serious environmental concern, as impact of exposure to these substances on human health remains unknown. While in vitro studies yield data on adverse effect of PSMPs, in vivo approaches are more relevant for risk assessment. Drosophila melanogaster is one of the most genetically and experimentally accessible model organisms used in biology as an in vivo model. D. melanogaster was selected as a representative in vivo model organism to examine the genotoxic potential of PSMPs at 5 concentrations of three different sizes namely 4, 10, or 20 µm. In particular, the wing somatic mutation and recombination test (SMART), a scalable, time-efficient in vivo assay developed to study genotoxicity of various compounds in a rapid manner at low costs was used. The third-instar Drosophila larvae were exposed to PSMPs through food at 5 concentrations ranging from 0.01-10 mM. Viability (lethality), larval length, morphological deformations, locomotor activity (climbing behavior), and genotoxic effects were the end-points measured. Exposure to PSMPs at 4, 10, or 20 µm produced significant morphological defects, impaired climbing behavior, and genotoxicity as evidenced by the SMART test demonstrating induction of somatic recombination. Significant increases were observed in the frequency of total spots, suggesting that PSMPs might induce genotoxic activity predominantly via initiation of somatic DNA recombination in a concentration-dependent manner.

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.

Genotoxicity and cytotoxicity evaluation of two thallium compounds using the Drosophila wing somatic mutation and recombination test

Thallium (Tl) is a heavy and toxic metal and a byproduct of several human activities, such as cement production, mining, and coal combustion. Thallium is found in fruits, vegetables, and animal fodder with high Tl contamination; therefore, it is an environmental pollution issue and a toxicological contamination problem for human beings and other organisms when exposed to it. The mutagenic potential of Tl and its compounds is controversial, and there are few in vivo studies on its effects. We conducted the animal bioassay Drosophila wing somatic mutation and recombination test (SMART) to test for genotoxicity and assessed the genotoxic effects of Tl acetate (TlCH₃COO) and Tl sulfate (Tl₂SO₄) on Drosophila melanogaster. Third instar larvae from the SMART standard cross (ST) were fed Tl acetate [0.2, 2, 20, 200, 600 and 1200 μM] and Tl sulfate [0.2, 2, 20, 200, and 600 μM]. Hexavalent chromium [CrO₃, 500 μM] served as the positive control, and Milli-Q water served as the negative control. Only the high Tl₂SO₄ [600 μM] concentration resulted in genotoxicity with 87.6% somatic recombination, and both salts disrupted cell division of wing imaginal disc cells, showing the expected cytotoxic effects. Genotoxic risks due to high metal levels by bioaccumulation of Tl⁺¹ or its compounds require further evaluation with other in vivo and in vitro assays.

Mutagenic and genotoxic activities of Phospholipase A2 Bothropstoxin-I from Bothrops jararacussu in Drosophila melanogaster and human cell lines

Phospholipase A₂ Bothropstoxin-I (PLA₂ BthTX-I) is a myotoxic Lys49-PLA₂ from Bothrops jararacussu snake venom. In order to evaluate the DNA damage caused by BthTX-I, we used the Somatic Mutation and Recombination Test (SMART) in Drosophila melanogaster and Comet assay in HUVEC and DU-145 cells. For SMART, different concentrations of BthTX-I (6.72 to 430 μg/mL) were used and no significant changes in the survival rate were observed. Significant frequency of mutant spots was observed for the ST cross at the highest concentration of BthTX-I due to recombinogenic activity. In the HB cross, BthTX-I increased the number of mutant spots at intermediate concentrations, being 53.75 μg/mL highly mutagenic and 107.5 μg/mL predominantly recombinogenic. The highest concentrations were neither mutagenic nor recombinogenic, which could indicate cytotoxicity in the wing cells of D. melanogaster. In vitro, all BthTX-I concentrations (1 to 50 μg/mL) induced decrease in HUVEC cell viability, as well as in DU-145 cells at concentrations of 10, 25, and 50 μg/mL. The comet assay showed that in HUVEC and DU-145 cells, all BthTX-I concentrations promoted increase of DNA damage. Further studies should be performed to elucidate the mechanism of action of PLA₂ BthTX-I and its possible use in therapeutic strategies against cancer.

In Vivo and In Vitro Assays Evaluating the Biological Activity of Taurine, Glucose and Energetic Beverages

Taurine is one of the main ingredients used in energy drinks which are highly consumed in adolescents for their sugary taste and stimulating effect. With energy drinks becoming a worldwide phenomenon, the biological effects of these beverages must be evaluated in order to fully comprehend the potential impact of these products on the health due to the fact nutrition is closely related to science since the population consumes food to prevent certain diseases. Therefore, the aim of this study was to evaluate the biological effects of taurine, glucose, classic Red Bull® and sugar-free Red Bull® in order to check the food safety and the nutraceutical potential of these compounds, characterising different endpoints: (i) Toxicology, antitoxicology, genotoxicology and life expectancy assays were performed in the Drosophila melanogaster model organism; (ii) The in vitro chemopreventive activity of testing compounds was determined by assessing their cytotoxicity, the proapoptotic DNA-damage capability to induce internucleosomal fragmentation, the strand breaks activity and the modulator role on the methylation status of genomic repetitive sequences of HL-60 promyelocytic cells. Whereas none tested compounds showed toxic or genotoxic effect, all tested compounds exerted antitoxic and antigenotoxic activity in Drosophila. Glucose, classic Red Bull® and sugar-free Red Bull® were cytotoxic in HL-60 cell line. Classic Red Bull® induced DNA internucleosomal fragmentation although none of them exhibited DNA damage on human leukaemia cells. In conclusion, the tested compounds are safe on Drosophila melanogaster and classic Red Bull® could overall possess nutraceutical potential in the in vivo and in vitro model used in this study. Besides, taurine could holistically be one of the bioactive compounds responsible for the biological activity of classic Red Bull®.

Toxicological and Epigenetic Studies of Two Types of Ale Beer, Tyrosol and Iso-Alpha Humulone

Although many benefits drawn from beer consumption are claimed, the epidemiological records are contradictory with respect to cancer prevention. The purpose of this study was to investigate the possible health-related activities involving genome safety and the ageing processes of two types of lyophilised ale beers (blond and stout), as well as two of their bioactive compounds (tyrosol and iso-alpha humulone). A multipurpose trial set of in vivo toxicity, antitoxicity, mutagenicity, antimutagenicity, lifespan and healthspan assays using Drosophila melanogaster were used. In parallel, several in vitro assays were designed using the cancer cell line HL-60 in order to establish the possible chemopreventive activity of the selected substances, where epigenetic modulation of DNA methylation changes, clastogenic activity and tumour cell inhibition growth were evaluated. The safety of the four substances was confirmed: lyophilised blond ale beer (LBAB), lyophilised stout ale beer (LSAB), tyrosol and iso-alpha humulone were neither toxic nor genotoxic. Moreover, all substances, except tyrosol, revealed the ability to protect individual genomes against oxidative radicals and to exert antimutagenic activity against the genotoxin hydrogen peroxide. With respect to the degenerative process indicators of lifespan and healthspan, tyrosol was the only compound that did not exert any influence on the life extension of Drosophila; LBAB induced a significant lifespan extension in D. melanogaster; LSAB and its distinctive compound iso-alpha humulone induced a reduction in longevity. The in vitro assays showed the cytotoxic activity of LBAB, LSAB and tyrosol against HL-60 cells. Moreover, proapoptotic DNA fragmentation or DNA strand breakage was observed for both types of beers and iso-alpha humulone at different concentrations. Furthermore, the lyophilised ale beers and tyrosol exhibited an increasing genome-wide methylation status, while iso-alpha humulone exhibited a demethylation status in repetitive cancer cell sequences. Although the biological activities assigned to beer consumption cannot be linked to any specific molecule/element due to the complexity of the phenolic profile, as well as the multifactor brewing process, the results obtained let us propose lyophilised ale beers as safe potential nutraceutical beverages when consumed in moderate amounts. The prevention of toxicity and genetic oxidative damage, as well as the induction of tumor cell death and modulation of the methylation status, are the key activities of beer that were shown in the present research.

Modulating effect of vitamin D3 on the mutagenicity and carcinogenicity of doxorubicin in Drosophila melanogaster and in silico studies

Vitamin D3 (VD3) deficiency increases DNA damage, while supplementation may exert a pro-oxidant activity, prevent viral infections and formation of tumors. The aim of this study was to investigate the mutagenicity and carcinogenicity of VD3 alone or in combination with doxorubicin (DXR) using the Somatic Mutation and Recombination Test and the Epithelial Tumor Test, both in Drosophila melanogaster. For better understanding of the molecular interactions of VD3 and receptors, in silico analysis were performed with molecular docking associated with molecular dynamics. Findings revealed that VD3 alone did not increase the frequency of mutant spots, but reduced the frequency of mutant spots when co-administered with DXR. In addition, VD3 did not alter the recombinogenic effect of DXR in both ST and HB crosses. VD3 alone did not increase the total frequency of tumor, but significantly reduced the total frequency of tumor when co-administered with DXR. Molecular modeling and molecular dynamics between calcitriol and Ecdysone Receptor (EcR) showed a stable interaction, indicating the possibility of signal transduction between VD3 and EcR. In conclusion, under these experimental conditions, VD3 has modulatory effects on the mutagenicity and carcinogenicity induced by DXR in somatic cells of D. melanogaster and exhibited satisfactory interactions with the EcR.

Food Safety and Nutraceutical Potential of Caramel Colour Class IV Using In Vivo and In Vitro Assays

Nutraceutical activity of food is analysed to promote the healthy characteristics of diet where additives are highly used. Caramel is one of the most worldwide consumed additives and it is produced by heating natural carbohydrates. The aim of this study was to evaluate the food safety and the possible nutraceutical potential of caramel colour class IV (CAR). For this purpose, in vivo toxicity/antitoxicity, genotoxicity/antigenotoxicity and longevity assays were performed using the Drosophila melanogaster model. In addition, cytotoxicity, internucleosomal DNA fragmentation, single cell gel electrophoresis and methylation status assays were conducted in the in vitro HL-60 human leukaemia cell line. Our results reported that CAR was neither toxic nor genotoxic and showed antigenotoxic effects in Drosophila. Furthermore, CAR induced cytotoxicity and hipomethylated sat-α repetitive element using HL-60 cell line. In conclusion, the food safety of CAR was demonstrated, since Lethal Dose 50 (LD₅₀) was not reached in toxicity assay and any of the tested concentrations induced mutation rates higher than that of the concurrent control in D. melanogaster. On the other hand, CAR protected DNA from oxidative stress provided by hydrogen peroxide in Drosophila. Moreover, CAR showed chemopreventive activity and modified the methylation status of HL-60 cell line. Nevertheless, much more information about the mechanisms of gene therapies related to epigenetic modulation by food is necessary.

Evaluation of mutagenic activity of platinum complexes in somatic cells of Drosophila melanogaster

Cisplatin, carboplatin, and oxaliplatin are some of the most often used alkylating chemotherapeutic agents. In view of the paucity of data on the genotoxicity of oxaliplatin, this study compares the mutagenic activity of cisplatin (0.006, 0.012, 0.025, 0.05 mM), carboplatin (0.1, 0.2, 0,5, 1.0 mM), and oxaliplatin (0.1, 0.2, 0,5, 1.0 mM) using the somatic mutation and recombination test (SMART) in Drosophila melanogaster. Standard and high-bioactivation crosses of the drosophilid were used, which present basal and high levels of cytochrome P450 (CYP450) metabolization enzymes, respectively. All concentrations of cisplatin and carboplatin induced lesions in genetic material in both crosses, while oxaliplatin was mutagenic only to high bioactivation flies treated with 0.1, 0.5 and 1 mM of the compound. No significant differences were observed between genotoxicity values of cisplatin and carboplatin. However, CYP450 enzymes may have affected the mutagenic action of oxaliplatin. Carboplatin induced mainly mutation events, while cisplatin triggered mostly mutation and recombination events when low and high doses were used. Most events induced by oxaliplatin were generated by somatic recombination. Important differences were observed in genotoxic potential of platinum chemotherapeutic compounds, possibly due to the origin and type of the lesions induced in DNA and the repair mechanisms involved.

Toxicological Studies of Czech Beers and Their Constituents

BACKGROUND

Czech beers are unique because they are brewed using specific technology at a particular latitude and for being entirely produced in the area of the Czech Republic. The purpose of this work is the evaluation of toxicological effects of a variety of freeze-dried Czech beers, their raw materials (malts, hops and yeast) and processed-beer (wort, hopped wort and young beer).

METHODS

In vivo assays to evaluate the safety and protective effects in the Drosophila melanogaster eukaryotic system, and the in vitro evaluations of chemopreventive and DNA damage activity using the HL-60 tumour human cell line were carried out.

RESULTS

The safe effects for all the analysed substances and general protective effects against H2O2 were shown both at the individual and genomic level in the Drosophila animal model, with some exceptions. Moreover, all the substances were able to inhibit the tumour cell growth and to induce DNA damage in the HL-60 cells at different levels (proapoptotic, single/double strands breaks and methylation status).

CONCLUSIONS

The promising effects shown by freeze-dried Czech beers due to their safety, protection against a toxin, chemopreventive potential and the induction of DNA damage in tumour cells, allow the proposition of Czech beer as a beverage with nutraceutic potential.

Nutraceutic Potential of Two Allium Species and Their Distinctive Organosulfur Compounds: A Multi-Assay Evaluation

This study aimed to evaluate the biological activities of two Allium species (garlic and onion) as well as diallyl disulphide (DADS) and dipropyl disulphide (DPDS) as their representative bioactive compounds in a multi-assay experimental design. The genotoxic, antigenotoxic, and lifespan effects of garlic, onion, DADS, and DPDS were checked in Drosophila melanogaster and their cytotoxic, pro-apoptotic, and DNA-clastogenic activities were analyzed using HL60 tumoral cells. All compounds were non-genotoxic and antigenotoxic against H₂O₂-induced DNA damage with a positive dose-response effect and different inhibition percentages (the highest value: 95% for DADS) at all tested concentrations. Daily intake of Allium vegetables, DADS, or DPDS had no positive effects on flies' lifespan and health span. Garlic and DADS exerted the highest cytotoxic effects in a positive dose-dependent manner. Garlic and DADS exerted a DNA-internucleosomal fragmentation as an index of induced proapoptotic activity on HL60 cells. Allium vegetables and DADS were able to induce clastogenic strand breaks in the DNA of HL60 cells. This study showed the genomic safety of the assayed substances and their protective genetic effects against the hydrogen peroxide genotoxine. Long-term treatments during the whole life of the Drosophila genetic model were beneficial only at low-median concentrations. The chemo-preventive activity of garlic could be associated with its distinctive organosulfur DADS. We suggest that supplementary studies are needed to clarify the cell death pathway against garlic and DADS.

Physicochemical Characterization and Biological Activities of Black and White Garlic: In Vivo and In Vitro Assays

White and three types of black garlic (13, 32, and 45 days of aging, named 0C1, 1C2, and 2C1, respectively) were selected to study possible differences in their nutraceutic potential. For this purpose, garlic were physicochemically characterized (Brix, pH, aW, L, polyphenol, and antioxidant capacity), and both in vivo and in vitro assays were carried out. Black garlic samples showed higher polyphenol content and antioxidant capacity than the white ones. The biological assays showed that none of the samples (neither raw nor black garlic) produced toxic effects in the Drosophila melanogaster animal genetic model, nor exerted protective effects against H₂O₂, with the exception of the 0C1 black garlic. Moreover, only white garlic was genotoxic at the highest concentration. On the other hand, 0C1 black garlic was the most antigenotoxic substance. The in vivo longevity assays showed significant extension of lifespan at some concentrations of white and 0C1and 1C2 black garlic. The in vitro experiments showed that all of the garlic samples induced a decrease in leukemia cell growth. However, no type of garlic was able to induce proapoptotic internucleosomal DNA fragmentation. Taking into account the physicochemical and biological data, black garlic could be considered a potential functional food and used in the preventive treatment of age-related diseases. In addition, our findings could be relevant for black-garlic-processing agrifood companies, as the economical and timing costs can significantly be shortened from 45 to 13 days of aging.

Bisphenol A induced oxidative stress mediated genotoxicity in Drosophila melanogaster

This study investigates Bisphenol A (BPA) induced oxidative stress that mediates the genotoxicity in in vivo model Drosophila melanogaster. The calculated LC₅₀ for BPA was 12.35 μg/mL. The strains of D. melanogaster were reared in 0.1, 1.0, 2.5 and 5.0 μg/mL BPA treated food media from the embryonic stage (egg); oxidative stress and genotoxicity parameters were analyzed. Food intake analysis confirmed that BPA is not an anti feedant for Drosophila larvae and it consumed BPA containing food. Increased reactive oxygen species (ROS) and lipid peroxidation (LPO) and depletion of superoxide dismutase (SOD), catalase (CAT), glutathione (GSH) and glutathione-s-transferase (GST) antioxidant activities were observed in BPA treated groups compared to control. Positive single spots/wing frequencies were observed in standard (ST) and high bioactivation (HB) crosses of marker heterozygous (MH; mwh/flr3) and balancer heterozygous (BH; mwh/TM3) genotype flies indicating BPA is mutagenic and not recombinogenic. A significant increase in tail length and % tail DNA in Comet assay after BPA treatment reveals that BPA has a potential to induce the genotoxicity. Present study suggests that BPA exposure induces oxidative stress, which could be one of the possible mechanisms for induction of genotoxicity.

Genotoxicity of zinc oxide nanoparticles: an in vivo and in silico study

Zinc oxide (ZnO) NPs are being used worldwide in consumer products and industrial applications. Based on predefined pathways, this study synthesized and characterized the nanostructures of ZnO NPs. The genotoxic effects of these nanomaterials were evaluated using a short-term in vivo bioassay, the somatic mutation and recombination test (SMART) in Drosophila melanogaster. In addition, a systems biology approach was used to search for known and predicted interaction networks between ZnO and proteins. The results observed in this study after in vivo exposure indicate that ZnO NPs are genotoxic and that homologous recombination (HR) was the main mechanism inducing loss of heterozygosis in the somatic cells of D. melanogaster. The results of in silico analysis indicated that ZnO is associated with the nuclear factor-kappa-beta (NFKB) protein family. In accordance with this model, ZnO exposure decreases the levels of NFKB inhibitory protein in the cell, consequently increasing NFKB dimers in the nucleus and inducing DNA double strand breaks (DSB) repair via HR. This excess level of HR can be observed in the SMART results. Assessing the mutagenic/recombinagenic effect of nanomaterials is essential in the development of strategies to protect human and environmental integrity.

Mutagenic and recombinogenic assessment of widely used pesticides on Drosophila melanogaster

The mutagenic potential of selected widely used pesticides: p,p'-dichlorodiphenyltrichloroethane (DDT); fenitrothion; propoxur; deltamethrin, bifenthrin; imidacloprid and thiametoxam was assessed using the wing spot test. Third-instar larvae of standard Drosophila melanogaster cross (ST), trans-heterozygous for the third chromosome recessive markers, multiple wing hairs (mwh) and flare (flr3) were chronically exposed to test compounds. Feeding ended with pupation of the surviving larvae. Genetic changes induced in somatic cells of the wing’s imaginal discs, mutant spots observed in marker-heterozygous (MH) and balancer-heterozygous (BH) flies were compared using the wing spot test, to estimate the genotoxic effects of these pesticides. In conclusion, exposure to 30 mg/mL deltamethrin, 40 mg/mL imidacloprid, 100 µg/mL DDT showed mutagenic and recombinagenic effects in the Drosophila wing spot test. In addition the results of chronic treatments performed at high doses showed mutagenic and recombinagenic effects in both genotypes

Lead modulated Heme synthesis inducing oxidative stress mediated Genotoxicity in Drosophila melanogaster

The mechanism of lead (Pb) modulated heme synthesis pathway induced oxidative stress mediated genotoxicity using standard (ST) and high bioactivation (HB) crosses of Drosophila melanogaster was addressed in the present study. Third instar larvae derived from the ST or HB crosses were reared in sub lethal concentrations of lead acetate (PbAc) treated food media and showed that Pb was readily taken up and accumulated in the said crosses. Pb modulated heme synthesis was evident by significant reductions of δ-aminolevulinic acid dehydratase (δ-ALA-D) and cytochrome P450 (CYP450) and increased accumulation of δ-aminolevulinic acid (δ-ALA). The results have also demonstrated that Pb induced oxidative stress by overproducing reactive oxygen species (ROS) and lipid peroxidation (LPO) and depletion of the antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione (GSH) and glutathione-s-transferase (GST). Wing somatic mutation and recombination test (SMART) using ST and HB crosses revealed that Pb is mutagenic and weakly recombinogenic. By employing larval hemocytes, there was an increase in percent of tail DNA in alkaline comet compared to that of neutral comet revealing the DNA single strand breaks were the products of Pb modulated heme synthesis pathway induced oxidative free radicals. Based on these findings, it can be concluded that Pb modulated heme synthesis pathway induces oxidative stress that mediates the genotoxicity in D. melanogaster.

Evaluation of the genotoxic properties of nickel oxide nanoparticles in vitro and in vivo

Nickel-based nanoparticles (NPs) are new products with an increasing number of industrial applications that were developed in recent years. NiO NPs are present in several nanotechnological industrial products, and the characterization of their genotoxic potential is essential. The present study assessed the genotoxicity of NiO NPs in vivo and in vitro using the somatic mutation and recombination test in somatic cells of Drosophila melanogaster (SMART), the cytokinesis - block micronucleus assay (CBMN), and the comet assay in a V79 cell line. The NiO NPs used in this study were about 30 nm in mean size. Larvae of Drosophila melanogaster were exposed to 5 mL of five different concentrations (1.31, 2.62, 5.25, 10.5, and 21 mg/mL) of NiO NPs. In turn, V79 cells were treated with a concentration range of 15-2000 μg/mL NiO NPs. The SMART showed that all concentrations of NiO NPs are genotoxic to the standart (ST) cross when compared to the negative control. On the other hand, only the highest concentration (21 mg/mL) was genotoxic to the HB cross. Somatic recombination was the preferential mechanism lesions were induced in D. melanogaster. The results show that NiO NPs were mutagenic to V79 cells as assessed by the CBMN assay. Significant differences in the frequencies of micronuclei (MN) were observed using the highest NiO NP concentrations (250 and 500 μg/mL) in the 4- and 24-h treatments, but when 125 μg/mL NiO NPs was used, such difference was observed only in the 4-h exposure time. The comet assay revealed that 62, 125, 250 and 500 μg/mL NiO NPs induced a significant increase in DNA damage. The results observed in this study indicate that NiO NPs are genotoxic and mutagenic in vitro and in vivo.

Anti/genotoxic, longevity inductive, cytotoxic, and clastogenic-related bioactivities of tomato and lycopene

The aim of this study was to evaluate some biological activities of tomato as well as lycopene and to consider a new nutraceutic value for this fruit regarding to the protection against genetic damage and as a chemopreventive agent. Genotoxicity, DNA-protection against hydrogen peroxide, and lifespan properties of tomato and lycopene were assessed through wing spot test and longevity assay using the Drosophila in vivo model. Additionally, chemopreventive activity was investigated through cytotoxicity, DNA-fragmentation comet and annexin V FITC/PI assays using HL60 in vitro model. Results showed that: (i) tomato and lycopene are not genotoxic and protect against H₂ O₂ -induced damage; (ii) with respect to the lifespan, tomato and lycopene are harmless at the lowest concentration; (iii) tomato is cytotoxic in a dose-dependent manner, but not lycopene; (iv) tomato and lycopene do not induce internucleosomal DNA-fragmentation although they induce significant clastogenic activity at low level in the leukemia cells. To sum up, tomato is a good candidate to be considered as a nutraceutical substance. Furthermore, synergistic action among other components within tomato matrix could be the cause of the health effects observed in this vegetable, which are not fully explained by lycopene. Environ. Mol. Mutagen. 59:427-437, 2018. © 2018 Wiley Periodicals, Inc.

Role of Zucchini and Its Distinctive Components in the Modulation of Degenerative Processes: Genotoxicity, Anti-Genotoxicity, Cytotoxicity and Apoptotic Effects

Zucchini (Cucurbita pepo subsp. pepo) is a seasonal vegetable with high nutritional and medical values. Many useful properties of this fruit are attributed to bioactive compounds. Zucchini fruits ("Yellow" and "Light Green" varieties) and four distinctive components (lutein, β-carotene, zeaxanthin and dehydroascorbic acid) were selected. Firstly, the lutein, β-carotene, zeaxanthin and dehydroascorbic acid contents were determined in these fruits. Then, in order to evaluate the safety and suitability of their use, different assays were carried out: (i) genotoxicity and anti-genotoxicity tests to determine the safety and DNA-protection against hydrogen peroxide; (ii) cytotoxicity; and (iii) DNA fragmentation and Annexin V/PI (Propidium Iodide) assays to evaluate the pro-apoptotic effect. Results showed that: (i) all the substances were non-genotoxic; (ii) all the substances were anti-genotoxic except the highest concentration of lutein; (iii) "Yellow" zucchini epicarp and mesocarp exhibited the highest cytotoxic activity (IC50 > 0.1 mg/mL and 0.2 mg/mL, respectively); and (iv) "Light Green" zucchini skin induced internucleosomal DNA fragmentation, β-carotene being the possible molecule responsible for its pro-apoptotic activity. To sum up, zucchini fruit could play a positive role in human health and nutrition due to this fruit and its components were safe, able to inhibit significantly the H₂O₂-induced damage and exhibit anti-proliferative and pro-apoptotic activities toward HL60 (human promyelocytic leukemia cells) tumor cells. The information generated from this research should be considered when selecting potential accessions for breeding program purposes.

Assessment of the mutagenic, recombinogenic, and carcinogenic potential of amphotericin B in somatic cells of Drosophila melanogaster

Amphotericin B (AmB) is an antifungal antibiotic extracted from Streptomyces nodosus. Its fungicidal activity depends primarily on its binding to the sterol group that is present in fungal membranes. In view of the toxicity of this drug, the purpose of this study was to evaluate its mutagenic, carcinogenic, and recombinogenic activity, based on the wing somatic mutation and recombination test (SMART) and the epithelial tumor detection test (wts) applied to Drosophila melanogaster. Larvae were chronically treated with different concentrations of AmB (0.01, 0.02, and 0.04 mg/mL). The results revealed that AmB is a promutagen exhibiting increase in the number of spots on individuals from high bioactivation (HB) cross with a high level of cytochrome P450. The results also indicate that the main genotoxic event induced by AmB is recombinogenicity. Homologous recombination can act as a determinant at different stages of carcinogenesis. For verification of carcinogenic potential of this compound, larvae from the wts/mwh and wts/ORR, flr³ were treated with the same three AmB concentrations used in the SMART assay. The results did not provide evidence that AmB has carcinogenic potential in wts/mwh individuals. However, individuals from wts/ORR, flr³ developed tumors at the highest concentration tested.

Role of Choline in the Modulation of Degenerative Processes: In Vivo and In Vitro Studies

The purpose of the present study was to examine the nutraceutical potential of choline as an added value to its well-known brain nutrient role. Several toxicity, antitoxicity, genotoxicity, antigenotoxicity, and longevity endpoints were checked in the somatic mutation and recombination test in in vivo Drosophila animal model. Cytotoxicity in human leukemia-60 cell line (HL-60) promyelocytic and NIH3T3 mouse fibroblast cells, proapoptotic DNA fragmentation, comet assay, methylation status, and macroautophagy (MA) activity were tested in in vitro assays. Choline is not only safe but it is also able to protect against the DNA damage caused by an oxidative genotoxin. Moreover, it improves the life extension in the animal model. The in vitro results show that it is able to exhibit genetic damage against leukemia HL-60 cells. Single-strand breaks in DNA are observed at the molecular level in treatments with choline, although only a significant hypermethylation on the long interspersed elements-1 and a hypomethylation on the satellite-alpha DNA repetitive DNA sequences of HL-60 cells at the lowest concentration (0.447 mM) were observed. Besides, choline decreased MA at the lower assayed concentration and the MA response to topoisomerase inhibitor (etoposide) is maintained in the presence of treatment with 0.22 mM choline. Taking into account the hopeful results obtained in the in vivo and in vitro assays, choline could be proposed as a substance with an important nutraceutical value for different purposes.

Assessment of the mutagenic, recombinogenic and carcinogenic potential of fipronil insecticide in somatic cells of Drosophila melanogaster

Fipronil (FP) is an insecticide that belongs to the phenylpyrazole chemical family and is used to control pests by blocking GABA receptor at the entrance channel of the chlorine neurons. The aim of this study was to evaluate the mutagenic, recombinogenic and carcinogenic potential of FP. The mutagenic and recombinogenic effects were evaluated using the somatic mutation and recombination test (SMART) on wing cells of Drosophila melanogaster. Third instar larvae from standard (ST) and high bioactivation (HB) crosses were treated with different concentrations of FP (0.3, 0.7, 1.5 or 3.0 × 10^-5 mM). The results showed mutagenic effects at all concentrations tested in the HB cross; and all concentrations tested in the ST cross, except at concentration of 0.7 × 10^-5 mM. The carcinogenic effect of FP was assayed through the test for detection of epithelial tumor (warts) in D. melanogaster. Third instar larvae from wts/TM3 virgin females mated to mwh/mwh males were treated with different concentrations of FP (0.3, 0.7, 1.5 or 3.0 × 10^-5 mM). All these concentrations induced a statistically significant increase in tumor frequency. In conclusion, FP proved to be mutagenic, recombinogenic and carcinogenic in somatic cells of D. melanogaster.

Assessing genotoxicity of diuron on Drosophila melanogaster by the wing-spot test and the wing imaginal disk comet assay

The aim of this study was to evaluate the genotoxicity of the herbicide diuron in the wing-spot test and a novel wing imaginal disk comet assay in Drosophila melanogaster. The wing-spot test was performed with standard (ST) and high-bioactivation (HB) crosses after providing chronic 48 h treatment to third instar larvae. A positive dose-response effect was observed in both crosses, but statistically reduced spot frequencies were registered for the HB cross compared with the ST. This latter finding suggests that metabolism differences play an important role in the genotoxic effect of diuron. To verify diuron's ability to produce DNA damage, a wing imaginal disk comet assay was performed after providing 24 h diuron treatment to ST and HB third instar larvae. DNA damage induced by the herbicide had a significantly positive dose-response effect even at very low concentrations in both strains. However, as noted for the wing-spot test, a significant difference between strains was not observed that could be related to the duration of exposure between both assays. A positive correlation between the comet assay and the wing-spot test was found with regard to diuron genotoxicity.

Assessment of genotoxic, mutagenic, and recombinogenic potential of water resources in the Paranaíba River basin of Brazil: A case study

Exposure to certain pollutants induces a series of alterations in deoxyribonucleic acid (DNA) that may result in genotoxic/mutagenic effects in exposed individuals. The present study aimed to monitor genotoxic, mutagenic, and recombinogenic potential and consequently water quality in two streams in the Paranaíba River basin in the state of Minas Gerais, Brazil, using two bioindicator fish (Rhamdia quelen and Geophagus brasiliensis). The micronucleus (MN) test and somatic recombination and mutation test (SMART) were employed to assess DNA damage. The water quality index (WQI) at the reference site control (S1) due to its proximity to the river source was compared to Córrego do Óleo (S2) with respect to chemical parameter levels of biochemical oxygen demand (BOD), dissolved-oxygen rates (DO), and total solid and fecal coliform counts. These chemical parameters were above the permitted limits at Córrego do Óleo (S2). At a third site, Córrego Liso (S3), a poor WQI was detected, attributed to the influence of domestic and industrial activities where BOD, DO, total solid, fecal coliform, total phosphorus, and turbidity rates exceeded premissible limits. The MN frequencies and the numbers of MN per cell (CMN) at sites S2 and S3 were significantly higher than those at S1 in both species. It is of interest that the increased frequency of MN was similar to the positive control cyclophosphamide only at S3, suggesting that the effects of water contaminants were most severe at this site. At sites assessed (S2 and S3), there was a significant rise in somatic mutation and recombination in the wings of Drosophila melanogaster, indicating the presence of trace elements, mainly lead (Pb) and cadmium (Cd), in the effluents in the Paranaíba River basin sites.

Evaluation of titanium dioxide nanocrystal-induced genotoxicity by the cytokinesis-block micronucleus assay and the Drosophila wing spot test

Titanium dioxide nanocrystals (TiO2 NCs) crystalline structures include anatase, rutile and brookite. This study evaluated the genotoxic effects of 3.4 and 6.2 nm anatase TiO2 NCs and 78.0 nm predominantly rutile TiO2 NCs through an in vitro micronucleus (MN) assay using V79 cells and an in vivo somatic mutation and recombination test in Drosophila wings. The MN assay was performed with nontoxic concentrations of TiO2 NCs. Only anatase (3.4 nm) at the highest concentration (120 μM) induced genotoxicity in V79 cells. In the in vivo test, Drosophila melanogaster larvae obtained from standard (ST) or high bioactivation (HB) crosses were treated with TiO2 NCs. In the ST cross, no mutagenic effects were observed. However, in the HB cross, TiO2 NCs (3.4 nm) were mutagenic at 1.5625 and 3.125 mM, while 78.0 nm NCs increased mutant spots at all concentrations tested except 3.125 mM. Only the smallest anatase TiO2 NCs induced mutagenic effects in vitro and in vivo. For rutile TiO2 NCs, no clastogenic/aneugenic effects were observed in the MN assay. However, they were mutagenic in Drosophila. Therefore, both anatase and rutile TiO2 NCs induced mutagenicity. Further research is necessary to clarify the TiO2 NCs genotoxic/mutagenic action mechanisms.

Evaluation of mutagenic, recombinogenic and carcinogenic potential of (+)-usnic acid in somatic cells of Drosophila melanogaster

The main of this study was to evaluate the mutagenic and carcinogenic potential of (+) - usnic acid (UA), using Somatic Mutation and Recombination Test (SMART) and the test for detecting epithelial tumor clones (wts) in Drosophila melanogaster. Larvae from 72 ± 4 h from Drosophila were fed with UA (5.0, 10.0 or 20.0 mM); urethane (10.0 mM) (positive control); and solvent (Milli-Q water, 1% Tween-80 and 3% ethanol) (negative control). ST cross produced increase in total mutant spots in the individuals treated with 5.0, 10.0 or 20.0 mM of UA. HB cross produced spot frequencies in the concentration of 5.0 mM that were higher than the frequency for the same concentration in the ST cross. In the highest concentrations the result was negative, which means that the difference observed can be attributed, in part, to the high levels of P450, suggesting that increasing the metabolic capacity maximized the toxic effect of these doses. In the evaluation of carcinogenesis using the wts test, the results obtained for the same concentrations of UA show a positive result for the presence of tumors when compared to the negative control. We conclude that UA has recombinogenic, mutagenic and carcinogenic effects on somatic cells in D. melanogaster.

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.

In Vivo and In Vitro Genotoxic and Epigenetic Effects of Two Types of Cola Beverages and Caffeine: A Multiassay Approach

The aim of this work was to assess the biological and food safety of two different beverages: Classic Coca Cola™ (CCC) and Caffeine-Free Coca Cola (CFCC). To this end, we determined the genotoxicological and biological effects of different doses of lyophilised CCC and CFCC and Caffeine (CAF), the main distinctive constituent. Their toxic/antitoxic, genotoxic/antigenotoxic, and chronic toxicity (lifespan assay) effects were determined in vivo using the Drosophila model. Their cytotoxic activities were determined using the HL-60 in vitro cancer model. In addition, clastogenic DNA toxicity was measured using internucleosomal fragmentation and SCGE assays. Their epigenetic effects were assessed on the HL-60 methylation status using some repetitive elements. The experimental results showed a slight chemopreventive effect of the two cola beverages against HL-60 leukaemia cells, probably mediated by nonapoptotic mechanisms. Finally, CCC and CAF induced a global genome hypomethylation evaluated in LINE-1 and Alu M1 repetitive elements. Overall, we demonstrated for the first time the safety of this famous beverage in in vivo and in vitro models.

Vernonanthura polyanthes leaves aqueous extract enhances doxorubicin genotoxicity in somatic cells of Drosophila melanogaster and presents no antifungal activity against Candida spp

Abstract Vernonanthura polyanthes (Spreng.) A.J. Vega & Dematt. (Asteraceae), known as “assa-peixe”, has been used in ethnomedicine for the treatment of various diseases such as bronchitis, pneumonia, hemoptysis, persistent cough, internal abscesses, gastric and kidney stone pain. Moreover, some studies demonstrated that species of Genus Vernonia present antifungal activity. Due to the biological relevance of this species, the aim of this study was to investigate the toxic, genotoxic, antigenotoxic and antifungal potential of V. polyanthes leaves aqueous extract in somatic cells of Drosophila melanogaster or against Candida spp. The aqueous extract of the plant showed no toxic, genotoxic and antigenotoxic activity in the experimental conditions tested using the wing somatic mutation and recombination test (SMART/wing). However, when the extract was associated with doxorubicin, used in this work as a positive control, the mutagenic potential of doxorubicin was enhanced, increasing the number of mutations in D. melanogaster somatic cells. In the other hand, no inhibitory activity against Candida spp. was observed for V. polyanthes leaves aqueous extract using agar-well diffusion assay. More studies are necessary to reveal the components present in the V. polyanthes leaves aqueous extract that could contribute to potentiate the doxorubicin genotoxicity.