Exploring the multilevel hazards of thiamethoxam using Drosophila melanogaster

Process, advances, and perspectives of graphene oxide-SELEX for the development of aptamer molecular probes: A comprehensive review

BACKGROUND

Aptamers are screened via the systematic evolution of ligands by exponential enrichment (SELEX) and are widely used in molecular diagnostics and targeted therapies. The development of efficient and convenient SELEX technology has facilitated rapid access to high-performance aptamers, thereby advancing the aptamer industry. Graphene oxide (GO) serves as an immobilization matrix for libraries in GO-SELEX, making it suitable for screening aptamers against diverse targets.

RESULTS

This review summarizes the detailed steps involved in GO-SELEX, including monitoring methods, various sublibrary acquisition methods, and practical applications from its inception to the present day. In addition, the potential of GO-SELEX in the development of broad-spectrum aptamers is explored, and its current limitations for future development are emphasized. This review effectively promotes the application of the GO-SELEX technique by providing valuable insights and assisting researchers interested in conducting related studies.

SIGNIFICANCE AND NOVELTY

To date, no review on the topic of GO-SELEX has been published, making it challenging for researchers to initiate studies in this area. We believe that this review will broaden the SELEX options available to researchers, ensuring that they can meet the growing demand for molecular probes in the scientific domain.

Comparative transcriptome profiling of two pesticides, Acephate and Chlorantraniliprole in non-targeted insect model, Drosophila melanogaster

Acephate and chlorantraniliprole are two insecticides widely used in agricultural applications. Several studies were focused on the mode of action and related biological and cellular level expressions. However, the sub-lethal dose and related molecular expression level of acephate and chlorantraniliprole have not been evaluated or studied to the same degree. In this study, we investigated the sub-lethal toxicity of acephate and chlorantraniliprole in Drosophila melanogaster. The EC50 value was recorded with high difference, and is found to be 1.9 μg/ml and 0.029 μg/ml respectively for acephate and chlorantraniliprole, the difference is simply because of the different modes of action. The 1/5th EC50 concentration was selected for studying the pesticide induced transcriptomics in D. melanogaster. Both pesticides significantly altered the expression profile of several transcripts which are involved in proteolysis, detoxification, chromosome associated proteins and immune response genes and so on. The effect of both pesticides on D. melanogaster was further explored by screening the genes involved in toxicity, which were analyzed using, GO and KEGG pathways. The results revealed that the sub-lethal exposure of both pesticides caused significant changes in the global gene transcription profiles and each pesticide had their unique mode of alteration in the D. melanogaster.

Proteomic analysis reveals oxidative stress-induced activation of Hippo signaling in thiamethoxam-exposed Drosophila

Thiamethoxam (THIA) is a widely used neonicotinoid insecticide. However, the toxicity and defense mechanisms activated in THIA-exposed insects are unclear. Here, we used isobaric tags for relative and absolute quantitation (iTRAQ) proteomics technology to identify changes in protein expression in THIA-exposed Drosophila. We found that the antioxidant proteins Cyp6a23 and Dys were upregulated, whereas vir-1 was downregulated, which may have been detoxification in response to THIA exposure. Prx5 downregulation promoted the generation of reactive oxygen species. Furthermore, the accumulation of reactive oxygen species led to the induction of antioxidant defenses in THIA-exposed Drosophila, thereby enhancing the levels of oxidative stress markers (e.g., superoxide dismutase, glutathione S-transferase, and glutathione) and reducing catalase expression. Furthermore, the Hippo signaling transcription coactivator Yki was inactivated by THIA. Our results suggesting that Hippo signaling may be necessary to promote insect survival in response to neonicotinoid insecticide toxicity.

Developmental neurotoxic effects of bisphenol A and its derivatives in Drosophila melanogaster

As a result of the ban on bisphenol A (BPA), a hormone disruptor with developmental neurotoxicity, several BPA derivatives (BPs) have been widely used in industrial production. However, there are no effective methods for assessing the neurodevelopmental toxic effects of BPs. To address this, a Drosophila exposure model was established, and W¹¹¹⁸ was reared in food containing these BPs. Results showed that each BPs displayed different semi-lethal doses ranging from 1.76 to 19.43 mM. Exposure to BPs delayed larval development and affected axonal growth, resulting in the abnormal crossing of the midline of axons in the β lobules of mushroom bodies, but the damage caused by BPE and BPF was relatively minor. BPC, BPAF, and BPAP have the most significant effects on locomotor behavior, whereas BPC exhibited the most affected social interactions. Furthermore, exposure to high-dose BPA, BPC, BPS, BPAF, and BPAP also significantly increased the expression of Drosophila estrogen-related receptors. These demonstrated that different kinds of BPs had different levels of neurodevelopmental toxicity, and the severity was BPZ > BPC and BPAF > BPB > BPS > BPAP ≈ BPAl ≈ BPF > BPE. Therefore, BPZ, BPC, BPS, BPAF, and BPAP should be evaluated as potential alternatives to BPA.

A nano-delivery system expands the insecticidal target of thiamethoxam to include a devastating pest, the fall armyworm

Nano-delivery systems have been applied to deliver various synthetic/botanical pesticides to increase the efficiency of pesticide use and reduce the volumes of pesticides applied. Previous studies have supported the hypothesis that the nanocarriers can help expand the insecticidal target of pesticides to include non-target pests. However, the potential mechanism underlying this interesting phenomenon remains unclear. Herein, a widely applied star polycation (SPc) nanocarrier was synthesized to construct a thiamethoxam (TMX) nano-delivery system. The SPc-based delivery system could promote the translocation of exogenous substances across the membrane of Sf9 cells, increase the cytotoxicity of TMX against Sf9 cells by nearly 20%, and expand the insecticidal target of TMX to include Spodoptera frugiperda (the fall armyworm), with a 27.5% mortality increase at a concentration of 0.25 mg/mL. Moreover, the RNA-seq analysis demonstrated that the SPc could upregulate various transport-related genes, such as Rab, SORT1, CYTH, and PIKfyve, for the enhanced cellular uptake of TMX. Furthermore, enhanced cell death in larvae treated with the TMX-SPc complex was observed through changes in the expression levels of death-related genes, such as Casp7, BIRC5, MSK1, and PGAM5. The SPc-based nano-delivery system improved the cellular uptake of TMX and expanded its insecticidal target by adjusting the expression levels of death-related genes. The current study mainly identified the transport and cell death genes related to nanocarrier-based insecticidal target expansion, which is beneficial for understanding the bioactivity enhancement of the nano-delivery system.

Molecular toxicity and defense mechanisms induced by silver nanoparticles in Drosophila melanogaster

The widely use of silver nanoparticles (AgNPs) as antimicrobial agents gives rise to potential environmental risks. AgNPs exposure have been reported to cause toxicity in animals. Nevertheless, the known mechanisms of AgNPs toxicity are still limited. In this study, we systematically investigated the toxicity of AgNPs exposure using Drosophila melanogaster. We show here that AgNPs significantly decreased Drosophila fecundity, the third-instar larvae weight and rates of pupation and eclosion in a dose-dependent manner. AgNPs reduced fat body cell viability in MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays. AgNPs caused DNA damage in hemocytes and S2 cells. Interestingly, the mRNA levels of the entire metallothionein gene family were increased under AgNPs exposure as determined by RNA-seq analysis and validated by qRT-PCR, indicating that Drosophila responded to the metal toxicity of AgNPs by producing metallothioneins for detoxification. These findings provide a better understanding of the mechanisms of AgNPs toxicity and may provide clues to effect on other organisms, including humans.

Chronic exposure to the star polycation (SPc) nanocarrier in the larval stage adversely impairs life history traits in Drosophila melanogaster

BACKGROUND

Nanomaterials are widely used as pesticide adjuvants to increase pesticide efficiency and minimize environmental pollution. But it is increasingly recognized that nanocarrier is a double-edged sword, as nanoparticles are emerging as new environmental pollutants. This study aimed to determine the biotoxicity of a widely applied star polycation (SPc) nanocarrier using Drosophila melanogaster, the fruit fly, as an in vivo model.

RESULTS

The lethal concentration 50 (LC₅₀) value of SPc was identified as 2.14 g/L toward third-instar larvae and 26.33 g/L for adults. Chronic exposure to a sub lethal concentration of SPc (1 g/L) in the larval stage showed long-lasting adverse effects on key life history traits. Exposure to SPc at larval stage adversely impacted the lifespan, fertility, climbing ability as well as stresses resistance of emerged adults. RNA-sequencing analysis found that SPc resulted in aberrant expression of genes involved in metabolism, innate immunity, stress response and hormone production in the larvae. Orally administrated SPc nanoparticles were mainly accumulated in intestine cells, while systemic responses were observed.

CONCLUSIONS

These findings indicate that SPc nanoparticles are hazardous to fruit flies at multiple levels, which could help us to develop guidelines for further large-scale application.

The immunotoxicity of ten insecticides against insect hemocyte cells in vitro

Hemocytes in the hemolymph of insects perform innate immunity, but systematic studies to compare immunotoxicity of pesticides on hemocytes are still few. In this study, an insect hemocyte system was used to assess the impact of pesticides with different modes of action, which included loss of cell viability, inhibition of hemophagocytosis, and reduction of nitric oxide synthase (NOS) activity. Results showed that piericidin A was the most cytotoxic to hemocytes, chlorfluazuron and hexaflumuron were the next. Also, piericidin A, chlorfenapyr, and fipronil had strong inhibitory effects on hemophagocytosis, and the effects of piericidin A and chlorfenapyr were persistent, while that of fipronil was short-lived. Moreover, fenoxycarb and hexaflumuron selectively inhibited granulocyte phagocytosis, tebufenozide only showed inhibition on plasmatocyte phagocytosis, but both inhibitory effects were transient. Furthermore, fenoxycarb and hexaflumuron showed a short-term strong inhibitory effect on the activity of NOS, chlorfenapyr and piericidin A showed a weak induction of NOS activity, while other pesticides exhibited a strong induction. Taken together, piericidin A was the most toxic and imidacloprid was the least toxic to hemocytes, and the alterations in hemocyte functions compromised immunity.

Transcriptome Analysis to Identify Responsive Genes under Sublethal Concentration of Bifenazate in the Diamondback Moth, Plutella xylostella (Linnaeus, 1758) (Lepidoptera: Plutellidae)

Bifenazate is a novel acaricide that has been widely used to control spider mites. Interestingly, we found bifenazate had a biological activity against the diamondback moth (Plutella xylostella), one of the most economically important pests on crucifer crops around the world. However, the molecular mechanisms underlying the response of P. xylostella to bifenazate treatment are not clear. In this study, we first estimated the LC₃₀ dose of bifenazate for third-instar P. xylostella larvae. Then, in order to identify genes that respond to the treatment of this insecticide, the comparative transcriptome profiles were used to analyze the gene expression changes in P. xylostella larvae after exposure to LC₃₀ of bifenazate. In total, 757 differentially expressed genes (DEGs) between bifenazate-treated and control P. xylostella larvae were identified, in which 526 and 231 genes were up-regulated and down-regulated, respectively. The further Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that the xenobiotics metabolisms pathway was significantly enriched, with ten detoxifying enzyme genes (four P450s, five glutathione S-transferases (GSTs), and one UDP-Glucuronosyltransferase (UGT)) were up-regulated, and their expression patterns were validated by qRT-PCR as well. Interestingly, the present results showed that 17 cuticular protein (CP) genes were also remarkably up-regulated, including 15 CPR family genes. Additionally, the oxidative phosphorylation pathway was found to be activated with eight mitochondrial genes up-regulated in bifenazate-treated larvae. In contrast, we found some genes that were involved in tyrosine metabolism and purine pathways were down-regulated, indicating these two pathways of bifenazate-exposed larvae were significantly inhibited. In conclusion, the present study would help us to better understand the molecular mechanisms of sublethal doses of bifenazate detoxification and action in P. xylostella.

Retinal Toxicity Induced by Chemical Agents

Vision is an important sense for humans, and visual impairment/blindness has a huge impact in daily life. The retina is a nervous tissue that is essential for visual processing since it possesses light sensors (photoreceptors) and performs a pre-processing of visual information. Thus, retinal cell dysfunction or degeneration affects visual ability and several general aspects of the day-to-day of a person's lives. The retina has a blood-retinal barrier, which protects the tissue from a wide range of molecules or microorganisms. However, several agents, coming from systemic pathways, reach the retina and influence its function and survival. Pesticides are still used worldwide for agriculture, contaminating food with substances that could reach the retina. Natural products have also been used for therapeutic purposes and are another group of substances that can get to the retina. Finally, a wide number of medicines administered for different diseases can also affect the retina. The present review aimed to gather recent information about the hazard of these products to the retina, which could be used to encourage the search for more healthy, suitable, or less risky agents.

Non-additive gene interactions underpin molecular and phenotypic responses in honey bee larvae exposed to imidacloprid and thymol

Understanding the cumulative risk of chemical mixtures at environmentally realistic concentrations is a key challenge in honey bee ecotoxicology. Ecotoxicogenomics, including transcriptomics, measures responses in individual organisms at the molecular level which can provide insights into the mechanisms underlying phenotypic responses induced by one or more stressors and link impacts on individuals to populations. Here, fifth instar honey bee larvae were sampled from a previously reported field experiment exploring the phenotypic impacts of environmentally realistic chronic exposures of the pesticide imidacloprid (5 μg.kg^-1 for six weeks) and the acaricide thymol (250 g.kg^-1 applied via Apiguard gel in-hive for four weeks), both separately and in combination. RNA-seq was used to discover individual and interactive chemical effects on larval gene expression and to uncover molecular mechanisms linked to reported adult and colony phenotypes. The separate and combined treatments had distinct gene expression profiles which represented differentially affected signaling and metabolic pathways. The molecular signature of the mixture was characterised by additive interactions in canonical stress responses associated with oxidative stress and detoxification, and non-additive interactions in secondary responses including developmental, neurological, and immune pathways. Novel emergent impacts on eye development genes correlated with long-term defects in visual learning performance as adults. This is consistent with these chemicals working through independent modes of action that combine to impact common downstream pathways, and highlights the importance of establishing mechanistic links between molecular and phenotypic responses when predicting effects of chemical mixtures on ecologically relevant population outcomes.

Short exposure to nitenpyram pesticide induces effects on reproduction, development and metabolic gene expression profiles in Drosophila melanogaster (Diptera: Drosophilidae)

Although the toxicity of neonicotinoid insecticides has been demonstrated in several studies, the information on metabolism, behavior, and health risk remains limited and has raised concerns about its potential toxicity. Thus, in this study we assessed the effects of nitenpyram using different sublethal concentrations (one-third and one-tenth of the acute LC₅₀ values) on various developmental and metabolic parameters from gene expression regulation in Drosophila melanogaster (model system used worldwide in ecotoxicological studies). As a result, nitenpyram sublethal concentrations prolonged the developmental time for both pupation and eclosion. Additionally, nitenpyram sublethal concentrations significantly decreased the lifespan, pupation rate, eclosion rate, and production of eggs of D. melanogaster. Moreover, the mRNA expression of genes relevant for development and metabolism was significantly elevated after exposure. Mixed function oxidase enzymes (Cyp12d1), (Cyp9f2), and (Cyp4ae1), hemocyte proliferation (RyR), and immune response (IM4) genes were upregulated, whereas lifespan (Atg7), male mating behavior (Ple), female fertility (Ddc), and lipid metabolism (Sxe2) genes were downregulated. These findings support a solid basis for further research to determine the hazardous effects of nitenpyram on health and the environment.

Chlordane exposure causes developmental delay and metabolic disorders in Drosophila melanogaster

The incidence of metabolic diseases is increasing every year, and several studies have highlighted the activity of persistent organic pollutants (POPs) in causing hyperlipidemia and diabetes, and these compounds are considered to be endocrine disrupting chemicals (EDCs). Chlordane is classified as an endocrine disruptor, but the mechanism of how it functions is still unclear. This study investigates the effects of chlordane exposure on Drosophila larvae. Drosophila was cultured in diet containing 0.01 μM, 0.1 μM, 1 μM, 5 μM, and 10 μM chlordane, and the toxicity of chlordane, the growth and development of Drosophila, the homeostasis of glucose and lipid metabolism and insulin signaling pathway, lipid peroxidation-related indicators and Nrf2 signaling pathway were evaluated. We here found that exposure to high concentrations of chlordane decreased the survival rate of Drosophila and that exposure to low concentrations of chlordane caused disruption of glucose and lipid metabolism, increased insulin secretion and impairment of insulin signaling. Notably, it also led to massive ROS production and lipid peroxidation despite of the activation of Nrf2 signaling pathway, an important pathway for maintaining redox homeostasis. Collectively, chlordane causes lipid peroxidation and disrupts redox homeostasis, which may be a potential mechanism leading to impaired insulin signaling and the metabolism of glucose and lipid, ultimately affects Drosophila development.

Cloning and functional analysis of autophagy-related gene 7 in Bombyx mori, silkworm

Silkworm (Bombyx mori) is an important economic insect and an attractive model system. A series of autophagy-related genes (Atgs) are involved in the autophagic process, and these Atgs have been proved to play important roles in the development. Atg7 stands at the hub of two ubiquitin-like systems involving Atg8 and Atg12 in the autophagic vesicle. In the present study, we cloned and characterized a BmAtg7 gene in Bombyx mori. The open reading frame (ORF) of BmAtg7 was 1908 bp in length, and it encoded a polypeptide of 635 amino acids. BmAtg7 was highly expressed in the posterior silk gland, fatbody, and epidermis. The expression profile of BmAtg7 in the fatbody showed an increasing tendency from day 1 of the 5th instar to the prepupal stage. After chlorantraniliprole (CAP) exposure, the transcriptional level of BmAtg7 was continuously decreased. After depletion of BmAtg7 by RNAi, the expressions of BmAtg7, BmAtg8, and BmEcr were all downregulated, while the expression of BmJHBP2 was upregulated. However, depletion of BmAtg7 did not prevent the metamorphosis of silkworm from larvae to pupae, while the occurrence of such process was delayed. After the 20-hydroxyecdysone (20E) treatment, the expression characteristics of these four genes (BmAtg7, BmAtg8, BmEcr and BmJHBP2) were contrary to the results after depletion of BmAtg7. Our results suggested that although CAP exposure could significantly inhibit the expression of BmAtg7 continuously, the changes of BmAtg7 was not the key factor in CAP-induced metamorphosis defects.

The Power of Drosophila melanogaster for Modeling Neonicotinoid Effects on Pollinators and Identifying Novel Mechanisms

Neonicotinoids are the most widely used insecticides in the world and are implicated in the widespread population declines of insects including pollinators. Neonicotinoids target nicotinic acetylcholine receptors which are expressed throughout the insect central nervous system, causing a wide range of sub-lethal effects on non-target insects. Here, we review the potential of the fruit fly Drosophila melanogaster to model the sub-lethal effects of neonicotinoids on pollinators, by utilizing its well-established assays that allow rapid identification and mechanistic characterization of these effects. We compare studies on the effects of neonicotinoids on lethality, reproduction, locomotion, immunity, learning, circadian rhythms and sleep in D. melanogaster and a range of pollinators. We also highlight how the genetic tools available in D. melanogaster, such as GAL4/UAS targeted transgene expression system combined with RNAi lines to any gene in the genome including the different nicotinic acetylcholine receptor subunit genes, are set to elucidate the mechanisms that underlie the sub-lethal effects of these common pesticides. We argue that studying pollinators and D. melanogaster in tandem allows rapid elucidation of mechanisms of action, which translate well from D. melanogaster to pollinators. We focus on the recent identification of novel and important sublethal effects of neonicotinoids on circadian rhythms and sleep. The comparison of effects between D. melanogaster and pollinators and the use of genetic tools to identify mechanisms make a powerful partnership for the future discovery and testing of more specific insecticides.

Exploring the multilevel effects of triclosan from development, reproduction to behavior using Drosophila melanogaster

Triclosan (TCS) is widely used as an antibacterial agent, but its residue in the environment poses a great threat. In this study, Drosophila melanogaster were treated with series concentrations of TCS and the effects on development, behavior, reproduction, and oxidative stress indicators were investigated. The results showed that high concentrations of TCS severely interfered with the metamorphosis, resulting in lower hatching rate and longer development time. The hatching rate was only 75.00% ± 4.08% in 0.80 mg/mL TCS group. TCS also showed dose-dependent damage to the fertility of flies, causing ovarian defects and decreased the number of offspring. Almost no offspring adults hatched when exposed to high concentrations of TCS (0.50 and 0.80 mg/mL), and the hatching rate was 0% in 0.80 mg/mL TCS group. Larvae crawling, adult climbing and anti-starvation ability were also affected to varying degrees and showed hormesis. TCS could damage larval intestinal cells in a dose-dependent manner, and injury was lightened with culture time prolonging to 30 h. It is noteworthy that TCS caused redox imbalance with an increase on catalase (CAT) activity and decrease on reactive oxygen species (ROS) level. Our results conclude that TCS elicits multiple impacts on Drosophila and its rational use should be strengthened.

Identification of azadirachtin responsive genes in Spodoptera frugiperda larvae based on RNA-seq

The fall armyworm Spodoptera frugiperda (Lepidoptera: Noctuidae) is a polyphagous pest with 353 plant species as its hosts, including maize, sorghum, cotton, and rice. Azadirachtin is one of the most effective botanical insecticides. The effect of azadirachtin against S. frugiperda remains to be determined. Here we report strong growth inhibition of azadirachtin on S. frugiperda larvae under either 1.0 or 5.0 μg/g azadirachtin. To explore the relevant mechanisms, the larvae fed with normal artificial diet and with 1.0 μg/g azadirachtin exposure for 3 days were collected as samples for RNA-Seq. RNA-Seq on S. frugiperda larvae under different treatments identified a total of 24,153 unigenes, including 3494 novel genes, were identified. Among them, 1282 genes were affected by 1.0 μg/g azadirachtin exposure, with 672 up-regulated and 610 down-regulated. The impacted genes include 61 coding for detoxification enzymes (31 P450s, 7 GSTs, 11 CarEs, 7 UGTs and 5 ABC transporters), 31 for cuticle proteins, and several proteins involved in insect chitin and hormone biosynthesis. Our results indicated that azadirachtin could regulate the growth of S. frugiperda by affecting insect chitin and hormone biosynthesis pathway. The enhanced expression of detoxification enzymes might be related to detoxifying azadirachtin. These findings provided a foundation for further delineating the molecular mechanism of growth regulation induced by azadirachtin in S. frugiperda larvae.

Hazardous effects of octopamine receptor agonists on altering metabolism-related genes and behavior of Drosophila melanogaster

Recent reports demonstrate that octopamine receptor (OR) agonists such as formamidine pesticides cause reproductive and developmental toxicity through endocrine disrupting effects in both humans and animals. Herein, we studied the effects of different sublethal concentrations of OR agonists, Amitraz and Chlordimeform, on growth, development, and reproduction of D. melanogaster from a genotype perspective view. As a result, the sublethal concentrations for both OR agonists delayed the developmental time including pupation and eclosion. It significantly reduced the lifespan, eclosion rate, and production of eggs. The mRNA expression of genes relevant for development and metabolism was significantly changed after exposure to sublethal concentrations of both OR agonists. Octopamine receptor in mushroom bodies (Oamb), trehalase enzyme (Treh), hemocyte proliferation (RyR), and immune response (IM4) genes were upregulated whereas, trehalose sugar (Tret1-1), mixed function oxidase enzyme (Cyp9f2), lifespan (Atg7), male mating behavior (Ple), female fertility (Ddc), and lipid metabolism (Sxe2) genes were downregulated. These results support the conclusion that OR agonists activate the octopamine receptor in D. melanogaster leading to an increase of trehalase enzyme activity and degradation of trehalose sugar into free glucose which results in rapid energy exhaustion, hyperexcitation, and disturbing of the octopaminergic system in D. melanogaster.

Developmental and behavioural toxicity induced by acrylamide exposure and amelioration using phytochemicals in Drosophila melanogaster

Acrylamide, an environmental pollutant, is known to occur in food substances cooked at high temperatures. Studies on various models indicate acrylamide to cause several physiological conditions such as neuro- and reproductive toxicity, and carcinogenesis. In our study, exposure of Drosophila melanogaster (Oregon K strain) to acrylamide via their diet resulted in a concentration and time-dependent mortality, while the surviving flies exhibited significant locomotor deficits, most likely due to oxidative stress-induced neuronal damage. Also, Drosophila embryos exhibited signs of developmental toxicity as evidenced by the alteration in the migration of border cells and cluster cells during the developmental stages, concomitant to modulation in expression of gurken and oskar genes. Curcumin, a known antioxidant has been widely studied for its neuroprotective effects against acrylamide; however; very few studies focus on thymoquinone for its role against food toxicant. Our research focuses on the toxicity elicited by acrylamide and the ability of the antioxidants: thymoquinone, curcumin and combination of thereof, in reversing the same.

Pesticide-Virus Interactions in Honey Bees: Challenges and Opportunities for Understanding Drivers of Bee Declines

Honey bees are key agricultural pollinators, but beekeepers continually suffer high annual colony losses owing to a number of environmental stressors, including inadequate nutrition, pressures from parasites and pathogens, and exposure to a wide variety of pesticides. In this review, we examine how two such stressors, pesticides and viruses, may interact in additive or synergistic ways to affect honey bee health. Despite what appears to be a straightforward comparison, there is a dearth of studies examining this issue likely owing to the complexity of such interactions. Such complexities include the wide array of pesticide chemical classes with different modes of actions, the coupling of many bee viruses with ectoparasitic Varroa mites, and the intricate social structure of honey bee colonies. Together, these issues pose a challenge to researchers examining the effects pesticide-virus interactions at both the individual and colony level.

Obesogenic Effect of Sulfamethoxazole on Drosophila melanogaster with Simultaneous Disturbances on Eclosion Rhythm, Glucolipid Metabolism, and Microbiota

Antibiotics have recently gained attention because they are emerging environmental pollutants with obesogenic properties. In this study, Drosophila melanogaster were exposed to sulfamethoxazole (SMX), a sulfonamide antibiotic, and the effects were measured on circadian rhythm (represented by the eclosion rhythm), lipid metabolism, and microbiota. Circadian rhythm disorder was considered due to its connection with lipid metabolism and microbiota in association with obesity. SMX decreased the proportion of adult flies that eclosed in the morning (AM adults) and increased the proportion of PM adults. Moreover, SMX increased the body weight of PM adults, indicating that SMX exposure caused dysrhythmia in eclosion together with obesity. In measurements of key metabolites and metabolic enzymes, SMX exposure stimulated 3 indices in AM adults and 10 indices in PM adults. In AMP-activated protein kinase and insulin/IGF-1 signaling pathways, SMX upregulated six genes in AM adults and nine genes in PM adults. Finally, microbiota analysis demonstrated that SMX increased the Firmicutes/Bacteroides ratios (F/B) by 79.6- and 5.8-fold compared to concurrent controls in AM and PM adults. Collectively, these results suggest that SMX showed obesogenic effects accompanied with dysrhythmia and disturbances in lipid metabolism and microbiota. Further studies on the intrinsic connection are needed.