Hazardous effect of tannery solid waste leachates on development and reproduction in Drosophila melanogaster: 70kDa heat shock protein as a marker of cellular damage

Flubendiamide induced genetic and cellular damages directly influence the life cycle of the oriental leaf worm, Spodoptera litura

Indiscriminate uses of insecticide greatly damage the environment as well as non-target organisms. Thus, multiple levels of bioassays can help better management of our environment. Flubendiamide is a phthalic acid diamide insecticide that ceases the function of insect muscle leading to paralysis and death. Here, we aimed to explore the effects of Flubendiamide on the life cycle of Spodoptera litura vis-a-vis the mode of action. Fourth instar larvae of the same age (120 ± 2 h) and size were fed with different concentrations (20-80 μg/mL) of Flubendiamide for 12-72 h. We performed a pharmacokinetics study, different biochemical assays, p450, Ecdysone receptor (EcR) and other genes expression analyses by Real-Time PCR and gross damages by Dye exclusion assay and histopathology. Our results demonstrate that the mean concentration of Flubendiamide after 48 h is 9.907 μg/mL and (i) altered the molting, metamorphosis, and reproduction at 80 μg/mL (24 h) (ii) increases all oxidative stress parameters (ROS/RNS, MDA, 8OHdG), decreases oxidative defense mechanisms (SOD, CAT, GST) at 80 μg/mL (48 h) and p450 in a time and concentration-dependent manner, (iii) activates CncC/Maf apoptotic pathways at 80 μg/mL concentration at 24 h while the expression declined from 48 h onwards, (iii) downregulates the EcR expression in a time and concentration-dependent manner, which might be responsible for disturbed molting, metamorphosis, and reproduction, and (iv) increase the expression of apoptotic genes (Caspase 1, -3, and - 5), in time and concentration-dependent manner causing gross morphological and histological damages. In conclusion, indiscriminate use of this insecticide can affect the ecosystem and have the capacity to cause multiple hazardous effects on experimental organisms. Thus, it warrants further investigations to improve and optimize the integrated pest management packages, including Flubendiamide for better management.

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.

Cr(VI)-induced DNA damage is lessened by the modulation of hsp70 via increased GSH de novo synthesis in Drosophila melanogaster

Hexavalent chromium [Cr(VI)] is a genotoxic chemical, and in the chemical-exposed organism, oxidative stress is one of the leading causative mechanisms of genotoxicity. Heat shock protein-70 (Hsp70) is reported to be modulated in environmental chemical exposed organisms. Inadequate information on the protective role of Hsp70 in chemical-induced DNA lesions prompted us to investigate this possibility in a well-studied genetically tractable in vivo model Drosophila melanogaster. In the midgut cells of Cr(VI)-exposed hsp70-knockout (KO), -knockdown (KD), and -overexpression Drosophila strains, no significant change in double-strand breaks generation was observed in comparison to similarly exposed w ¹¹¹⁸ and the respective genetic control strain after 48 h. Therefore, the role of hsp70 was investigated on oxidative DNA damage induction in the exposed organisms after 24 h. Oxidized DNA lesions (particularly oxidized purine-based lesions), 8-oxo-dG level, and oxidative stress endpoints were found to be significantly elevated in hsp70-KO and -KD strains in comparison to similarly exposed w ¹¹¹⁸ and respective genetic control strain. On the contrary, in ubiquitous hsp70-overexpression strain exposed to Cr(VI), these endpoints were significantly lowered concurrently with increased GSH level through elevated gclc, and gclm expression, Gclc level, and GCL activity. The study suggests that as a consequence of hsp70 overexpression, the augmented GSH level in cells vis-a-vis GSH de novo synthesis can counteract Cr(VI)-induced oxidized DNA lesions.

Novel insights into biodegradation, interaction, internalization and impacts of high-aspect-ratio TiO2 nanomaterials: A systematic in vivo study using Drosophila melanogaster

The elongated nature of the high-aspect-ratio nanomaterials (NMs) can help us to obtain valuable information on its biodegradation, physical interaction with target-cells, and internalization. Three different length nano-titanium have been studied using Drosophila, TEM, and different biological markers. Nano-titanium, regardless of its shape, was eroded and degraded just entering the gut lumen of the larvae. Results showed that the distinguished shape of nanowires helps to understand the interactions of NMs with the intestinal barrier. The peritrophic membrane, as the first defense line of the intestinal barrier, succeeded in the reservation of NMs, though the perpendicular particles of nanowires stabbing it, making pores, and permitting their translocation into intestinal cells. On the other side, the exposure to TiO₂NPs did not decrease egg-to-adult viability, but all its different shapes, especially nanowires, mediated a wide molecular response including changes of expression in genes involved in stress, antioxidant, repair, and physical interaction responses. All these changes concerning their ability to elevate ROS levels ultimately led to potential genotoxicity. So, the high aspect ratio NMs are efficient in understanding the outstanding issues of NMs exposure, but at the same time could induce genotoxic impact rather than the low aspect ones.

Protective effect of Catharanthus roseus plant extracts against endosulfan and its isomers induced impacts on non-targeted insect model, Drosophila melanogaster and live brain cell imaging

Endosulfan has been recognized as a highly controversial pesticide due to its acute toxicity, potential bioaccumulation, persistency, and long-range atmospheric transport. Several plant extracts act as antioxidant agents against wide-range of pesticide toxicity hazards through the free radicals scavenging properties. Plants' secondary metabolites are considered as efficient protective agents against various cellular toxic injuries. Understanding these properties of botanicals, several researchers currently focused on the detoxification and ameliorative potency of plant extracts against highly toxic chemicals. In our studies, we focused on the endosulfan total and its isomers (alpha and beta) induced changes on Drosophila melanogaster and their ameliorative effects by co-administrated with methanolic and aqueous extracts of Catharanthus roseus whole plant. We selected the 1/5th EC₅₀ concentration of alpha-endosulfan, beta-endosulfan, and endosulfan (total) and co-administrated with 1/50th EC₅₀ concentration of aqueous and methanolic extracts and evaluated their ameliorative effects, in terms of verifying the life stage activities, protein profiling and also by using live brain cells imaging. We finally concluded that, the methanolic and aqueous extracts inhibit the toxic impacts caused by endosulfan and its isomers and also increasing the survival rate of the test organism.

Interaction of thiamethoxam with DNA: Hazardous effect on biochemical and biological parameters of the exposed organism

In the present scenario, insecticides/pesticides are used intensively to control the various insect pests. Indiscriminate use of these insecticides/pesticides affects the structure and function of the ecosystem. In this context, a thorough toxicological study of each insecticide/pesticide is a must to understand the hazardous effect of these chemicals on the target and non-target organisms. The present study was aimed to understand the hazardous effect of thiamethoxam against the Spodoptera litura. Different concentrations (20-80 μg/mL) of thiamethoxam were prepared, and fourth instar larvae of S. litura were allowed to feed for 12-72 h. We first examined the interaction of thiamethoxam with DNA. Next, treated and non-treated larvae were assessed for different biological parameters such as mortality, emergence, fecundity, fertility, longevities, and biochemical parameters. Our result showed that thiamethoxam directly interacts with the DNA and significantly influenced the different biological and biochemical parameters of exposed the organisms. We observed a significant change in stress enzymes such as SOD, CAT, and GST. A similar observation was also made with the oxidative marker for lipid damage, MDA and DNA damage, 8-OHdG, respectively. In conclusion, our results suggest that improper use of synthetic chemical insecticides influenced both biological and biochemical parameters through oxidative stress and probably damage the genetic material.

Hazardous sub-cellular effects of Fipronil directly influence the organismal parameters of Spodoptera litura

Indiscriminate use of insecticides/pesticides affects the structure and function of the ecosystems. The present study was aimed to investigate the toxic potential of Fipronil (a second generation phenylpyrazole) using Spodoptera litura larvae (Lepidoptera: Noctuidae) as an experimental model. Commercial grade of Fipronil, an insecticide was fed (20-80 mg/L) to the 4th instar larvae of S. litura for 12-72 h and examined different molecular, biochemical and organismal parameters. We observed a significant dose- and time-dependent changes in the biochemical parameters such as Superoxide dismutase (SOD), Glutathione-S-transferase (GST), Catalase (CAT), level of 8-hydroxy 2'-deoxyguanosine (8-OHdG) and Thiobarbituric Acid Reactive Substances (TBARS) [Malondialdehyde (MDA) equivalent] in the exposed larvae. We also observed that Fipronil interacts with DNA. Next, we examined the influence of sub-cellular damages at the organismal level. The alterations in the parameter such as the delayed emergence of larvae, reduced fecundity, fertility and increased rate of malformation in pupae and adults indicate the sub-organismal damages influence at the organismal level. The findings of the present study suggest that discriminatory non-scientific use of insecticide/pesticide might influence the population dynamics of insects and in large ecosystem too and needs further thorough investigations.

Evaluation of sewage sludge incineration ash as a potential land reclamation material

This study evaluated the potential of utilising sewage sludge incineration ash as a land reclamation material. Toxicity assessment of the leachate of the ash was carried out for both terrestrial and marine organisms. Both the fruit fly Drosophila melanogaster and barnacle Amphibalanus amphitrite showed that both bottom and fly ash leached at liquid-to-solid (L/S) ratio 5 did not substantially affect viabilities. The leachate carried out at L/S 10 was compared to the European Waste Acceptance Criteria and the sewage sludge ashes could be classified as non-hazardous waste. The geotechnical properties of the sewage sludge ash were studied and compared to sand, a conventional land reclamation material, for further evaluation of its potential as a land reclamation material. It was found from direct shear test that both bottom and fly ashes displayed similar and comparable shear strength to that of typical compacted sandy soil based on the range of internal friction angle obtained. However, the consolidation profile of bottom ash was significantly different from sand, while that of fly ash was more similar to sand. Our study showed that the sewage sludge ash has the potential to be used as a land reclamation material.

Effects of tannery wastewater exposure on adult Drosophila melanogaster

Our aim was to evaluate the effects of exposure to tannery wastewater on mortality and/or antioxidant enzyme system in adult wild-type Canton-S Drosophila melanogaster. Exposure to tannery wastewater induced a concentration-dependent lethality in adult Canton-S flies. Tannery wastewater was able to alter antioxidant enzyme activities, specifically glutathione peroxidase-like and glutathione S-transferase, in adult Canton-S D. melanogaster. We conclude that D. melanogaster is a reliable model to evaluate the toxicity induced by tannery wastewater.

A review on green synthesis of silver nanoparticles and their applications

Development of reliable and eco-accommodating methods for the synthesis of nanoparticles is a vital step in the field of nanotechnology. Silver nanoparticles are important because of their exceptional chemical, physical, and biological properties, and hence applications. In the last decade, numerous efforts were made to develop green methods of synthesis to avoid the hazardous byproducts. This review describes the methods of green synthesis for Ag-NPs and their numerous applications. It also describes the comparison of efficient synthesis methods via green routes over physical and chemical methods, which provide strong evidence for the selection of suitable method for the synthesis of Ag-NPs.

Comparison of quartz vials with polypropylene vials for rapid cryopreservation of human ovarian tissue

Background

Because higher survival of follicles during the freezing/thawing procedure improves the quality of cryopreserved tissue reimplanted after oncological therapies, defining an optimal method for human ovarian tissue cryopreservation remains a major issue in this field. One option to improve the cryopreservation procedure is to use better materials, i.e., vials with better conductivity. The aim of this study was to compare polypropylene (PP) with quartz vials. Between September 2012 and January 2013, eight patients were recruited. The ovarian cortex was cut into 3 slices, assigned randomly to a fresh and a cryopreserved group in PP (method B) or quartz vials (method C). Histological and immunohistochemical (IHC) analysis were used. For IHC three antibodies were analyzed: Ki67 (proliferation index), Bcl2 (anti apoptotic index) and Hsp70 (stress index).

Results

The majority of GCs showed positive staining for Bcl2 in both cryopreservation device, with higher expression in group C than in group B. Oocytes and their nuclei showed intense positive staining for ki67 in both methods B and C, and also a patch positive stromal cells staining for Ki67. Expression of hsp70 was not increased after cryopreservation.

Conclusions

Cryopreservation using quartz vials led to larger numbers of good follicles while maintaining consistent preservation for stromal cells and vessels.

The impact of green tea polyphenols on development and reproduction in Drosophila melanogaster

Although, green tea has numerous health benefits, adverse effects with excessive consumption have been reported. Using Drosophila melanogaster, a decrease in male fertility with green tea was evidenced. Here, the extent of green tea toxicity on development and reproduction was investigated. Drosophila melanogaster embryos and larvae were exposed to various doses of green tea polyphenols (GTP). Larvae exposed to 10 mg/mL GTP were slower to develop, emerged smaller, and exhibited a dramatic decline in the number of emerged offspring. GTP protected flies against desiccation but sensitized them to starvation and heat stress. Female offspring exhibited a decline in reproductive output and decreased survival while males were unaffected. GTP had a negative impact on reproductive organs in both males and females (e.g., atrophic testes in males, absence of mature eggs in females). Collectively, the data show that high doses of GTP adversely affect development and reproduction of Drosophila melanogaster.

Antioxidant and antigenotoxic properties of CeO2 NPs and cerium sulphate: Studies with Drosophila melanogaster as a promising in vivo model

Although in vitro approaches are the most used for testing the potential harmful effects of nanomaterials, in vivo studies produce relevant information complementing in vitro data. In this context, we promote the use of Drosophila melanogaster as a suitable in vivo model to characterise the potential risks associated to nanomaterials exposure. The main aim of this study was to evaluate different biological effects associated to cerium oxide nanoparticles (Ce-NPs) and cerium (IV) sulphate exposure. The end-points evaluated were egg-to-adult viability, particles uptake through the intestinal barrier, gene expression and intracellular reactive oxygen species (ROS) production by haemocytes, genotoxicity and antigenotoxicity. Transmission electron microscopy images showed internalisation of Ce-NPs by the intestinal barrier and haemocytes, and significant expression of Hsp genes was detected. In spite of these findings, neither toxicity nor genotoxicity related to both forms of cerium were observed. Interestingly, Ce-NPs significantly reduced the genotoxic effect of potassium dichromate and the intracellular ROS production. No morphological malformations were detected after larvae treatment. This study highlights the importance of D. melanogaster as animal model in the study of the different biological effects caused by nanoparticulated materials, at the time that shows its usefulness to study the role of the intestinal barrier in the transposition of nanomaterials entering via ingestion.

Synergistic effects of toxic elements on heat shock proteins

Heat shock proteins show remarkable variations in their expression levels under a variety of toxic conditions. A research span expanded over five decades has revealed their molecular characterization, gene regulation, expression patterns, vast similarity in diverse groups, and broad range of functional capabilities. Their functions include protection and tolerance against cytotoxic conditions through their molecular chaperoning activity, maintaining cytoskeleton stability, and assisting in cell signaling. However, their role as biomarkers for monitoring the environmental risk assessment is controversial due to a number of conflicting, validating, and nonvalidating reports. The current knowledge regarding the interpretation of HSPs expression levels has been discussed in the present review. The candidature of heat shock proteins as biomarkers of toxicity is thus far unreliable due to synergistic effects of toxicants and other environmental factors. The adoption of heat shock proteins as "suit of biomarkers in a set of organisms" requires further investigation.

Inhibitional effects of metal Zn²⁺ on the reproduction of Aphis medicaginis and its predation by Harmonia axyridis

BACKGROUND

Contamination, including metals, can disturb the reproductive processes of many organisms, including both prey and predatory insects. However, there is virtually no information on the effects of high level Zinc (Zn) pollution on aphids and ladybirds. The high concentrations of Zn²⁺ or Zn pollution inhibit reproduction in the phytophagous aphid, Aphis medicaginis, and the predatory ladybird Harmonia axyridis could provide important information.

RESULTS

It was observed in this study that Zn concentrations in Vicia faba (broad bean) seeds and seedlings in all Zn²⁺ treatments were significantly higher than that in the control group, and increased with increasing Zn²⁺ concentrations in the solution. The rate of reproduction in A. medicaginis declined significantly (p<0.05) over time in the five groups fed on broad bean seedlings treated with different concentrations of Zn²⁺ solution compared with the control group. These results showed that higher concentrations of Zn²⁺ significantly inhibited the reproductive capacity of A. medicaginis. We also cloned and identified a gene encoding vitellogenin (Vg) from A. medicaginis, which has an important role in vitellogenesis, and therefore, reproduction was affected by exposure to Zn²⁺. Expression of AmVg was reduced with increasing exposure to Zn²⁺ and also in the F1-F3 generations of aphids exposed to different Zn²⁺ concentrations. Predation by H. axyridis was also reduced in aphids exposed to high-levels of Zn²⁺. Similarly, ovipositioning by H. axyridis was also reduced.

CONCLUSIONS

Our results suggest that Zn²⁺ can significantly affect the reproductive capacity of both A. medicaginis and its predator H. axyridis, the former through effects on the expression of AmVg and the latter through avoidance of aphids containing high levels of Zn²⁺.

Sperm functional parameters and erythrocytes oxidant-antioxidant imbalance during municipal landfill leachate treatment withdrawal in rats

Adequate information on how leachates affect hematological and reproductive functions is necessary to help in linking causality with predictable response. The present study investigated the effects of Olushosun municipal landfill leachate (OMLL) exposure and withdrawal on sperm characteristics and erythrocytes oxidant-antioxidant balance in rats. Adult male Wistar rats were exposed to 0%, 12.5% and 25% OMLL in drinking water for 28 days. One-half of the rats in each group were sacrificed on day 29 while the remaining one-half stayed an additional 28 days without treatment. OMLL exposure significantly decreased sperm functional parameters, disrupted antioxidant systems with concomitant elevation in hydrogen peroxide and malondialdehyde levels in erythrocytes and sperm. Following withdrawal of treatment, OMLL-mediated decrease in sperm count and daily sperm production were reversed to near control. However, erythrocytes and sperm oxidative damage, increased sperm abnormalities, decreased epididymis weight, sperm progressive motility and testicular sperm number persisted and were consistent with results obtained from rats sacrificed immediately after OMLL treatment. Collectively, OMLL-induced irreversible oxidative damage to erythrocytes and sperm in rats within the time course of investigation. These findings highlight potential adverse effects of OMLL on individuals unduly exposed to leachates contaminated substances.

Involvement of oxidative stress in municipal landfill leachate-induced toxicity in boar sperm

Exposure to leachates generated from an improperly managed hazardous waste dump sites is detrimental to human health and the ecosystem. The present study investigated the effect of Olushosun municipal landfill leachate (OMLL) on sperm characteristics and antioxidant systems in boar sperm cells. The sperm cells were incubated with the leachate at final concentrations of 0, 1, 2, 4 and 8% for 3h at 37 °C. Sperm characteristics were monitored hourly during the incubation period whereas aminotransferases activities and oxidative stress indices were determined after the incubation period. Results revealed a time- and dose-dependent decline in sperm progressive motility from 1h post-treatment with 2, 4 and 8% OMLL whereas decreased sperm viability with elevated abnormalities were observed from 2 h post-treatment with 4 and 8% OMLL when compared with control. Exposure to OMLL caused a significant increase in aminotransferases, catalase and glutathione-S-transferase activities whereas it markedly decreased superoxide dismutase and glutathione peroxidase activities without affecting glutathione level in the treated sperm cells. Co-incubation of sperm with OMLL increased the levels of hydrogen peroxide and malondialdehyde levels. In conclusion, OMLL elicited spermatotoxicity via induction of oxidative stress possibly generated through an enhanced intracellular reactive oxygen species.

The mitochondrial uncoupler 2,4-dinitrophenol attenuates sodium nitroprusside-induced toxicity in Drosophila melanogaster: potential involvement of free radicals

The toxicity of sodium nitroprusside (SNP) (an inducer of oxidative/nitrosative stress) and the attenuation of SNP effects by 2,4-dinitrophenol (DNP) (that induces mild uncoupling of respiration) were evaluated in the Drosophila melanogaster model system. Fly larvae were raised on food supplemented with 1.0 mM SNP, 0.5 or 1.25 mM DNP, or with mixtures 1.0 mM SNP plus 0.5 or 1.25 mM DNP. Food supplementation with SNP decreased larval viability and pupation height whereas supplementation with DNP substantially reversed these changes. Biochemical analyses of oxidative stress markers and activities of antioxidant and associated enzymes were carried out on 2-day-old flies emerged from control larvae and larvae fed on food supplemented with SNP, DNP, or SNP/DNP mixtures. Larval exposure to SNP lowered activities of aconitase, while the presence of DNP reduced the negative impact of SNP by raising aconitase activity back to near control levels. Larval treatment with SNP also elevated the contents of carbonyl protein, uric acid and low molecular mass thiols and produced higher activities of superoxide dismutase, glutathione S-transferase, glucose-6-phosphate dehydrogenase and thioredoxin reductase in adult flies. However, the presence of DNP in the food mixtures prevented SNP-induced changes in thioredoxin reductase and glucose-6-phosphate dehydrogenase activities, as well as uric acid and low-molecular-mass thiol content. The potential mechanisms by which DNP exerts protective effects against SNP toxicity are discussed.

Zinc effect on the sea urchin Paracentrotus lividus immunological competence

Pollution by heavy metals has become one of the most important problems in marine coastal areas as a consequence of anthropogenic inputs. Among metal contaminants, zinc, being considered not very toxic, is sometimes released into the sea in appreciable quantities and its concentration is loosely regulated. In this work we analyzed the effects of a high zinc concentration on the sea urchin Paracentrotus lividus immune system. In particular, after 24 h of zinc treatment, we evaluated coelomocytes morphology and composition as well as the zinc influence on some humoral parameters such as hemolysis, lysozyme-like activity and antibacterial activity on Vibrio alginolyticus. Our results evidenced that the presence of zinc affected both cellular and acellular components of the sea urchin immune system. The P. lividus coelomocytes changed in morphology and number; moreover, the amebocytes changed from a petaloid to a filipodial-like shape and the red spherula cells increased in number. Among the considered humoral effectors lysozyme-like activity and antibacterial activity on V. alginolyticus decreased in short-term to zinc treatment. The modifications in the sea urchin immunological competence might give an early indication of disease susceptibility thus suggesting to consider the examined defence mechanisms as potential biological indicators of metal pollution.

The potential toxic effects of cerium on organism: cerium prolonged the developmental time and induced the expression of Hsp70 and apoptosis in Drosophila melanogaster

Due to the widespread application of cerium, a rare earth element, the risk of exposure to cerium has increased. Therefore, understanding the physiological effects of cerium is of great importance. Our previous work showed that cerium caused significant lifespan shortening accompanied by oxidative damage in Drosophila melanogaster, however, little is known about the detailed mechanism of cerium-induced cytotoxicity. Thus, we examined the developmental time during metamorphosis, and assessed the toxic effects of cerium by evaluating heat shock protein 70 (Hsp70), DNA damage markers and apoptosis in D. melanogaster. We found that cerium extended the developmental time of D. melanogaster and up-regulated the expression of Hsp70 when the concentration of cerium was increased (especially concentrations over 26.3 μg/g). Up-regulation of the cell cycle checkpoint p53 and cell signaling protein p38 were also observed when the concentration of cerium was over 104 μg/g. In addition, the activities of caspase-3 and caspase-9, markers of apoptosis, were significantly higher when the larvae were exposed to ceric sulfate. These results suggest that high concentrations of cerium may result in DNA damage and ultimately apoptosis in D. melanogaster, and strongly indicate that cerium should be applied with caution and the potential toxic effects in humans should also be taken into consideration.

Organochlorine pesticide, endosulfan induced cellular and organismal response in Drosophila melanogaster

The effect of endosulfan (0.02-2.0μgmL(-1)) to Drosophila melanogaster (Oregon R(+)) at the cellular and organismal levels was examined. Third instar larvae of D. melanogaster and the strains transgenic for hsp70, hsp83 and hsp26 were exposed to endosulfan through food for 12-48h to examine the heat shock proteins (hsps), reactive oxygen species (ROS) generation, anti-oxidant stress markers and xenobiotic metabolism enzymes. We observed a concentration- and time-dependent significant induction of only small hsps (hsp23>hsp22) in the exposed organism in concurrence with a significant induction of ROS generation, oxidative stress and xenobiotic metabolism markers. Sub-organismal response was to be propagated towards organismal response, i.e., delay in the emergence of flies and decreased locomotor behaviour. Organisms with diminished locomotion also exhibited significantly lowered acetylcholinesterase activity. A significant positive correlation observed among ROS generation and different cellular endpoints (small hsps, oxidative stress markers, cytochrome P450 activities) in the exposed organism indicate a modulatory role of ROS in endosulfan-mediated cellular toxicity. The study thus suggests that the adverse effects of endosulfan in exposed Drosophila are manifested both at cellular and organismal levels and recommends Drosophila as an alternative animal model for screening the risk caused by environmental chemicals.

Nanotoxicity: Dimensional and Morphological Concerns

Nanotechnology deals with the construction of new materials, devices, and different technological systems with a wide range of potential applications at the atomic and molecular level. Nanomaterials have attracted great attention for numerous applications in chemical, biological, and industrial world because of their fascinating physicochemical properties. Nanomaterials and nanodevices are being produced intentionally, unintentionally, and manufactured or engineered by different methods and released into the environment without any safety test. Nantoxicity has become the subject of concern in nanoscience and nanotechnology because of the increasing toxic effects of nanomaterials on the living organisms. Nanomaterials can move freely as compared to the large-sized particles; therefore, they can be more toxic than bulky materials. This review article delineates the toxic effects of different types of nanomaterials on the living organisms through different sources, like water, air, contact with skin, and the methods of determinations of these toxic effects.

Environmental chemical mediated male reproductive toxicity: Drosophila melanogaster as an alternate animal model

Industrialization and indiscriminate use of agrochemicals have increased the human health risk. Recent epidemiological studies raised a concern for male reproduction given their observations of reduced sperm counts and altered semen quality. Interestingly, environmental factors that include various metals, pesticides and their metabolites have been causally linked to such adversities by their presence in the semen at levels that correlate to infertility. The epidemiological observations were further supported by studies in animal models involving various chemicals. Therefore, in this review, we focused on male reproductive toxicity and the adverse effects of different environmental chemicals on male reproduction. However, it is beyond the scope of this review to provide a detailed appraisal of all of the environmental chemicals that have been associated with reproductive toxicity in animals. Here, we provided the evidence for reproductive adversities of some commonly encountered chemicals (pesticides/metals) in the environment. In view of the recent thrust for an alternate to animal models in research, we subsequently discussed the contributions of Drosophila melanogaster as an alternate animal model for quick screening of toxicants for their reproductive toxicity potential. Finally, we emphasized the genetic and molecular tools offered by Drosophila for understanding the mechanisms underlying the male reproductive toxicity.