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Neonicotinoid insecticides (NNI) are agonists of insect nicotinic acetylcholine receptors (nAChR) that induce non-elucidate mechanisms of abnormal behavior in insects. In this work, we investigated the effects of sublethal doses of the neonicotinoid thiamethoxam (TMX) on neurochemical and physiological parameters in cockroaches. Sublethal doses of TMX (0.01-10 ng.g -1 body mass) caused significant alterations in most of the neurophysiological parameters evaluated. TMX reduced sustained locomotor activity by 19.9-25.8 %, depending on the dose. Leg grooming activity increased by 124.5 ± 3.4 %, 158.7 ± 3.5 %, 168.3 ± 3.4 %, and 160.4 ± 3.4 % (mean ± SEM) with TMX doses of 0.01, 0.1, 1, and 10 ng.g -1 , respectively. Exploratory activity was significantly reduced only at the lowest TMX dose (0.01 ng.g -1 ) - the time spent immobile increased from 30 % to ∼45 %, whereas none of the doses affected the walking speed. Treatment with TMX (0.01 ng.g -1 ) markedly reduced the olfactory sensitivity of the cockroaches and also reduced the mechanosensory action potential amplitude, rise time and decay time by 61.2 ± 19 %, 50 ± 4 %, and 76.8 ± 9.5 %, respectively. In semi-isolated heart preparations, TMX caused positive chronotropism (increases of 34.7 ± 15.9 %, 26.8 ± 7.8 %, 43.0 ± 16.5 %, and 19.0 ± 13.7 % for 0.01, 0.1, 1, and 10 ng of TMX, respectively). TMX attenuated the activity of glutathione-S-transferase by 35.1 ± 6.4 % at the highest dose tested (10 ng.g -1 ). TMX caused alterations in the metal ion content of cockroach brains that varied with the dose tested and the ion examined. These findings indicate that sublethal doses of TMX can interfere with normal neurological function in cockroaches and disrupt brain metal ion homeostasis., Competing Interests: Declaration of competing interest The authors have no competing financial interests or personal relationships related to this work and its publication., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The neurotoxic effects of neonicotinoids (NEOs) have been widely reported in relation to the poisoning of wild birds, yet the underlying molecular mechanism has remained elusive. This study employed Japanese quails (Coturnix japonica) and primary quail embryonic neurons as in vivo and ex vivo models, respectively, to investigate the neurotoxic effects and mechanism of thiamethoxam (TMX), a representative neonicotinoid insecticide, at environmentally relevant concentrations. Following a 28-day exposure to TMX, metabolomic analysis of quail brain revealed TMX-induced changes in glutamatergic, GABA-ergic, and dopaminergic function. Subsequent ex vivo and in silico experimentation revealed that the activation of nicotinic acetylcholine receptors and calcium signaling, induced by clothianidin (CLO), the primary metabolite of TMX, served as upstream events for the alterations in neurotransmitter synthesis, metabolism, release, and uptake. Our findings propose that the disruption of the central nervous system, caused by environmentally significant concentrations of NEOs, may account for the avian poisoning events induced by NEOs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

New mixtures of pesticides are being placed on the market to increase the spectrum of phytosanitary action. Thus, the eco(geno)toxic effects of the new commercial mixture named Platinum Neo, as well as its constituents the neonicotinoid Thiamethoxam and the pyrethroid Lambda-Cyhalothrin, were investigated using the species Daphnia magna, Raphidocelis subcapitata, Danio rerio, and Allium cepa L. The lowest- and no-observed effect concentration (LOEC and NOEC) were measured in ecotoxicological tests. While Thiamethoxam was ecotoxic at ppm level, Lambda-Cyhalothrin and Platinum Neo formulation were ecotoxic at ppb level. The mitotic index (MI), chromosomal aberrations and micronucleus [MN] frequency were measured as indicators of phytogenotoxicity in A. cepa plants exposed for 12 h to the different insecticides and their mixture under different dilutions. There were significant alterations in the MI and MN frequency in comparison with the A. cepa negative control group, with Thiamethoxam, Lambda-Cyhalothrin, and Platinum Neo treatments all significantly reducing MI and increasing MN frequency. Thus, MI reduction was found at 13.7 mg L -1 for Thiamethoxam, 0.8 μg L -1 for Lambda-Cyahalothrin, and 2.7:2 μg L -1 for Platinum Neo, while MN induction was not observed at 14 mg L -1 for Thiamethoxam, 0.8 μg L -1 for Lambda-Cyahalothrin, and 1.4:1 μg L -1 for Platinum Neo. The insecticide eco(geno)toxicity hierarchy was Platinun Neo > Lambda-Cyhalothrin > Thiamethoxam, and the organism sensitivity hierarchy was daphnids > fish > algae > A. cepa. Eco(geno)toxicity studies of new pesticide mixtures can be useful for management, risk assessment, and avoiding impacts of these products on living beings., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Claudemir Marcos Radetski reports financial support was provided by FAPESC. Claudemir M. Radetski reports a relationship with FAPESC that includes: funding grants. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The widespread application of neonicotinoid insecticides (NNIs) has attracted widespread attention to their potential ecotoxicological effects. In this study, we systematically evaluated the toxic effects of thiamethoxam (TMX) and its metabolite clothianidin (CLO) on earthworms (Eisenia fetida). Specifically, the antioxidant system responses and endogenous metabolite metabolism responses in earthworms were analyzed in the temporal dimension after 7, 14, 21 and 28 days of exposure to TMX and CLO. The results found that TMX and CLO could inhibit the growth phenotype of earthworms and cause significant changes in antioxidant system related indicators. More importantly, we found that TMX and CLO could cause significant changes in the metabolic profiles of earthworms through NMR-based metabolomics. From the changes in endogenous metabolites, the toxicity effects of TMX on earthworms gradually increases with prolonged exposure time. Differently, the toxicity effects of CLO on earthworms is significantly higher than that of TMX in the early stages of exposure. Meanwhile, these impacts will not weaken with prolonged exposure time. Furthermore, the results of KEGG enrichment pathway analysis indicated that TMX and CLO could significantly interfere with energy homeostasis, redox homeostasis, osmotic regulation, amino acid metabolism and protein synthesis in earthworms. These findings further deepen our understanding of the ecotoxicological effects of NNIs on soil organism., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Indoxacarb is a chiral insecticide that consists of two enantiomers, S-(+)-indoxacarb and R-(-)-indoxacarb, of which only S-(+)-indoxacarb has insecticidal activity. Previous enantioselective toxicology studies of indoxacarb focused mostly on simple environmental model organisms. The lack of a toxicology evaluation of indoxacarb conducted in a mammalian system could mean that the extent of the potential health risk posed by the insecticide to humans is not adequately known. In this study, we reported on a new pair of enantiomers, S-IN-RM294 and R-IN-RM294, derived from the metabolic breakdown of S-(+)-indoxacarb and R-(-)-indoxacarb, respectively, in rats. The toxicokinetics of S-(+)-indoxacarb, R-(-)-indoxacarb, S-IN-RM294, and R-IN-RM294 in rats were evaluated to provide a more comprehensive risk assessment of these molecules. The bioavailability and excretion rates of both S-(+)-indoxacarb and R-(-)-indoxacarb were relatively low, which may be due to their faster metabolism and accumulation in the tissues. In addition, there were significant differences in the metabolism and distribution between the two indoxacarb enantiomers and their metabolites in vivo. S-(+)-Indoxacarb was found to be more easily metabolized in the blood compared with R-(-)-indoxacarb, as shown by the differences in pharmacokinetic parameters between oral and intravenous administration. Analysis of their tissue distribution showed that S-(+)-indoxacarb was less likely to accumulate in most tissues. The results obtained for the two metabolites were consistent with those of the two parent compounds. S-IN-RM294 was more readily cleared from the blood and less likely to accumulate in the tissues compared with R-IN-RM294. Therefore, whether from the perspective of insecticidal activity or from the perspective of mammalian and environmental friendliness, the application of optically pure S-(+)-indoxacarb in agriculture may be a more efficient and safer strategy., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

We investigated the effects of neonicotinoid pesticides (NEOs) on the spontaneous swimming and foraging behavior, as well as the morphological and physiological changes of goldfish. Most fish reared in thiamethoxam (THM)-sprayed rice fields showed the scales easily peeled off, and increased ascites. Some individuals showed decreased bio-defense activity and low plasma Ca 2+ . Similar changes were found in the exposure test to THM (1.0 and 20.0 μg/L) and dinotefuran (1.2 and 23.5 μg/L). Next, the effects of a low concentration of THM (1.0 μg/L) on the spontaneous swimming and foraging behavior of fish were examined. Fish exposed to THM for 1 week became restless and had increased the swimming performance, especially under natural light, white LED lighting and blue LED lighting. Goldfish exposed to THM had also increased intake of shiny white beads under green LED illumination. These results indicate that the exposure to NEO, even for a short period and at low levels, not only suppressed bio-defense activities and metabolic abnormalities, but also stress response, the swimming and foraging behavior of the fish are likely to be significantly suffered., (© 2024 The Author(s). Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society.)

This study was designed to investigate the toxic effects of two frequently used commercial insecticides containing endosulfan and indoxacarb on a freshwater amphipod Gammarus kischineffensis. In this context, the 24, 48, 72 and 96 h LC50 values of these pesticides were determined for G. kischineffensis. Then the histopathological effects of these pesticides on the gill tissues of this species were evaluated. At the end of the study, the 96 h LC50 values of commercial-grade endosulfan and indoxacarb for G. kischineffensis were determined as 1.861 μg L -1 and 20.212 mg L -1 , respectively. Histopathologically, the most common histopathological alterations in individuals exposed to sublethal concentrations of commercial-grade endosulfan and indoxacarb were pillar cell hypertrophy resulting in atrophy of the hemocoelic space and hemocytic infiltration. Considering these results, it can be said that commercial-grade endosulfan is extremely and indoxacarb is slightly toxic to G. kischineffensis., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) (Lepidoptera, Noctuidae), is a highly polyphagous invasive pest that damages various crops. Pesticide control is the most common and effective strategy to control FAW. In this study, we evaluated the toxicity of metaflumizone and indoxacarb against third-instar FAW larvae using the insecticide-incorporated artificial diet method under laboratory conditions. Both metaflumizone and indoxacarb exhibited substantial toxicity against FAW, with LC 50 values of 2.43 and 14.66 mg/L at 72 h, respectively. The sublethal effects of metaflumizone and indoxacarb on parental and F1 generation FAW were investigated by exposing third-instar larvae to LC 10 and LC 30 concentrations of these insecticides. Sublethal exposure to these two insecticides significantly shortened adult longevity, extended pupal developmental times and led to reduced pupal weight, pupation rates, and adult fecundity in the treated parental generation and F1 generation at LC 10 or LC 30 concentrations, in comparison to the control group. The larval developmental times were shortened in the parental generation but prolonged in the F1 generation, after being treated with sublethal concentrations of metaflumizone. Furthermore, larvae exposed to LC 10 or LC 30 concentrations of indoxacarb exhibited elevated activity levels of cytochrome P450 monooxygenase and glutathione S-transferase, which coincides with the observed synergistic effect of piperonyl butoxide and diethyl maleate. In conclusion, the high toxicity and negative impact of metaflumizone and indoxacarb on FAW provided significant implications for the rational utilization of insecticides against this pest., Competing Interests: Declaration of competing interest The authors declare that there is no conflict of interests regarding the publication of this article., (Copyright © 2024. Published by Elsevier Inc.)

Indoxacarb is one of the most extensively used oxadiazine insecticides worldwide, but it may exert detrimental effects on ecosystems, population dynamics, and health. Due to the lack of knowledge on the ecotoxicity of indoxacarb, it is still challenging to assess whether this insecticide poses an ecotoxicological impact on terrestrial environments. Therefore, our study aims to provide novel data on the toxic effects of 28-day dietary exposure to commercial grade indoxacarb at two environmentally relevant concentrations, 0.02 µg/mL and tenfold (0.2 µg/mL) on the model species, Theba pisana. Their effects were studied using a multiple biomarker approach by evaluating physiological, biochemical, and histopathological responses. After 28 days of treatment, indoxacarb at both concentrations significantly reduced the food intake and growth of the treated snails. Also, it caused decreases in lipid peroxidation (LPO)  levels after 7 and 14 days of exposure, whereas an opposite effect occurred after 21 and 28 days. All treated snails were found to exhibit a lower content of glutathione (GSH) after all times of exposure. Moreover, catalase (CAT), glutathione-S-transferase (GST), and glutathione peroxidase (GPx) activities, as well as protein content (PC), were elevated in the treated snails after all time intervals. Post exposure to both realistic indoxacarb concentrations, changes in acetylcholinesterase (AChE) activity between a decrease and an increase were observed. Furthermore, indoxacarb caused histo-architectural changes in the hepatopancreas of T. pisana. Our results demonstrate that, at environmentally relevant concentrations, indoxacarb poses negative consequences for T. pisana, indicating its ecotoxicological impacts., (© 2024. The Author(s).)

The high water solubility and ecotoxicity of thiamethoxam (TMX) is a potential hazard to ecosystems and human health. Here, a strain of Bacillus cereus with high TMX degradation activity was isolated from the sediment of the A 2 O process in the wastewater treatment plant and was able to utilize TMX as its sole carbon source. Under different environmental conditions, the degradation efficiency of TMX by Bacillus cereus-S1 (strain S1) ranged from 41.0% to 68.9% after 216 h. The optimum degradation conditions were DO = 3.5 mg/L and pH 9.0. The addition of an appropriate carbon-to-nitrogen ratio could accelerate the degradation of TMX. A plausible biodegradation pathway has been proposed based on the identified metabolites and their corresponding degradation pathways. TMX can be directly converted into Clothianidin (CLO), TMX-dm-hydroxyl and TMX-Urea by a series of reactions such as demethylation, oxadiazine ring cleavage and C=N substitution by hydroxy group. The main products were TMX-dm-hydroxyl and TMX-Urea, the amount of CLO production is relatively small. This study aims to provide a new approach for efficient degradation of TMX; furthermore, strain S1 is a promising biological source for in situ remediation of TMX contamination., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

As an important economic insect, Bombyx mori plays an essential role in the development of the agricultural economy. Indoxacarb, a novel sodium channel blocker insecticide, has been widely used for the control of various pests in agriculture and forestry, and its environmental pollution caused by flight control operations has seriously affected the safe production of sericulture in recent years. However, the lethal toxicity and adverse effects of indoxacarb on silkworm remain largely unknown. In this study, the toxicity of indoxacarb on the 5th instar larvae of silkworm was determined, with an LC 50 (72 h) of 2.07 mg/L. Short-term exposure (24 h) to a low concentration of indoxacarb (1/2 LC 50 ) showed significantly reduced body weight and survival rate of silkworm larvae. In addition, indoxacarb also led to decreased cocoon weight and cocoon shell weight, but had no significant effects on pupation, adult eclosion, and oviposition. Histopathological and ultrastructural analysis indicated that indoxacarb could severely damage the structure of the midgut epithelial cells, and lead to physiological impairment of the midgut. A total of 3883 differentially expressed genes (DEGs) were identified by midgut transcriptome sequencing and functionally annotated using GO and KEGG. Furthermore, the transcription level and enzyme activity of the detoxification related genes were determined, and our results suggested that esterases (ESTs) might play a major role in metabolism of indoxacarb in the midgut of B. mori. Future studies to examine the detoxification or biotransformation function of candidate genes will greatly enhance our understanding of indoxacarb metabolism in B. mori. The results of this study provide a theoretical basis for elucidating the mechanism of toxic effects of indoxacarb on silkworm by interfering with the normal physiological functions of the midgut., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Inc.)

Neonicotinoid insecticides, known for their selectivity and low mammalian toxicity, have been widely used in recent years as alternatives to organophosphate insecticides. Although neonicotinoids are generally considered to be safe, data show that they can cause harmful effects on human and environmental health. Due to the lack of information on their mechanism of toxicity, the effects of imidacloprid and thiamethoxam on DNA methylation as the most used marker for epigenetic effects were investigated in human neuroblastoma (SH-SY5Y) cells. The cells were exposed to imidacloprid and thiamethoxam in concentrations of 100, 200, and 500 μM for 24 hours, then global DNA methylation and expression of genes involved in global DNA methylation ( DNMT1 , DNMT3a and DNMT3b ) were investigated. Global DNA methylation significantly increased after imidacloprid exposure at 100 μM, and thiamethoxam exposures at 200 µM and 500 μM (>1.5-fold). Imidacloprid significantly decreased the expression of DNMT1 and DNMT3a , whereas thiamethoxam did not cause any significant changes in the expression of DNMT genes. Our findings suggested that alteration in global DNA methylation may be involved in the toxic mechanisms of imidacloprid and thiametoxam.

Dung beetles (Coleoptera: Scarabaeinae) frequently traverse agricultural matrices in search of ephemeral dung resources and spend extended periods of time burrowing in soil. Neonicotinoids are among the most heavily applied and widely detected insecticides used in conventional agriculture with formulated products designed for row crop and livestock pest suppression. Here, we determined the comparative toxicity of two neonicotinoids (imidacloprid and thiamethoxam) on dung beetles, Canthon spp., under two exposure profiles: direct topical application (acute) and sustained contact with treated-soil (chronic). Imidacloprid was significantly more toxic than thiamethoxam under each exposure scenario. Topical application LD50 values (95% CI) for imidacloprid and thiamethoxam were 19.1 (14.5-25.3) and 378.9 (200.3-716.5) ng/beetle, respectively. After the 10-day soil exposure, the measured percent mortality in the 3 and 9 µg/kg nominal imidacloprid treatments was 35 ± 7% and 39 ± 6%, respectively. Observed mortality in the 9 µg/kg imidacloprid treatment was significantly greater than the control (p = 0.04); however, the 3 µg/kg imidacloprid dose response may be biologically relevant (p = 0.07). Thiamethoxam treatments had similar mortality as the controls (p > 0.8). Environmentally relevant concentrations of imidacloprid measured in airborne particulate matter and non-target soils pose a potential risk to coprophagous scarabs., (© 2023. The Author(s).)

The frequent application of second-generation neonicotinoids thiamethoxam (TMX) and clothianidin (CLO) has led to a high detectable rate in environment samples and poses threats to nontarget organisms and human beings, however, the information on the influences of long-term exposure at low doses was limited. In this study, the tissue distribution of TMX and CLO in mice at acceptable daily intake (ADI) level and 5 × ADI was determined and the health effects were assessed. TMX and CLO were detected in the liver, serum, lung, heart and kidney in the TMX exposure groups, which indicated that TMX degraded to CLO in mice. Residue levels of TMX in tissues increased with the increasing of doses. The concentrations of CLO in different tissues in the CLO exposure groups were in the order C kidney  > C lung  > C heart  > C liver . Measurement of biochemical indicators, combined with metabolomic analysis of liver, kidney, and cecal contents, examination of changes in the gut microbiota, and histopathological assessment indicated that both TMX and CLO affected energy absorption and lipid metabolism in mice and destroyed tissue structures. Furthermore, we found that CLO had a stronger effect on metabolism in mice, despite its lower acute toxicity. These results have prompted us to consider the chronic toxicity and potential hazards of chemicals in future risk assessments., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

The accumulation of lipid droplets in hepatocytes is a key feature of drug-induced liver injury (DILI) and can be induced by a subset of hepatotoxic compounds. In the present study, we optimized and evaluated an in vitro technique based on the fluorescent dye Nile Red, further named Nile Red assay to quantify lipid droplets induced by the exposure to chemicals. The Nile Red assay and a cytotoxicity test (CTB assay) were then performed on cells exposed concentration-dependently to 60 different compounds. Of these, 31 were known to induce hepatotoxicity in humans, and 13 were reported to also cause steatosis. In order to compare in vivo relevant blood concentrations, pharmacokinetic models were established for all compounds to simulate the maximal blood concentrations (C max ) at therapeutic doses. The results showed that several hepatotoxic compounds induced an increase in lipid droplets at sub-cytotoxic concentrations. To compare how well (1) the cytotoxicity test alone, (2) the Nile Red assay alone, and (3) the combination of the cytotoxicity test and the Nile Red assay (based on the lower EC 10 of both assays) allow the differentiation between hepatotoxic and non-hepatotoxic compounds, a previously established performance metric, the Toxicity Separation Index (TSI) was calculated. In addition, the Toxicity Estimation Index (TEI) was calculated to determine how well blood concentrations that cause an increased DILI risk can be estimated for hepatotoxic compounds. Our findings indicate that the combination of both assays improved the TSI and TEI compared to each assay alone. In conclusion, the study demonstrates that inclusion of the Nile Red assay into in vitro test batteries may improve the prediction of DILI compounds., (Copyright © 2022. Published by Elsevier B.V.)

Chiral pesticides are unique hazardous materials. Here, we systematically studied the potentially harmful products of enantioselective indoxacarb degradation throughout tea growth, processing, and brewing and tested their toxicity to tea geometrid larvae and honeybees. The half-lives of S-indoxacarb and R-indoxacarb during tea growth were 2.6 d and 3.3 d, respectively. There was a trend toward the production of S-indoxacarb from R-indoxacarb. The degradation products IN-JT333, IN-MK638, IN-MF014, and IN-KG433 were also characterized in tea growth and processing and detected. IN-JT333, previously known as a direct insecticidal compound produced by the enzymatic transformation of indoxacarb in insects, was first found in plant samples. The fixation and rolling of green tea and the rolling of black tea were the most important steps that affected indoxacarb and its degradation products. The leaching rates of R-indoxacarb and S-indoxacarb were slightly higher in green tea than in black tea. The maximum leaching rates of IN-MK638 and IN-MF014 during the brewing process reached 89.9% and 94.1%, respectively. Contact toxicity tests with honeybees and tea geometrid larvae in the lab showed that the relative toxicities of the compounds could be ranked as follows: S-indoxacarb > indoxacarb (3S + 1R) ≫ R-indoxacarb. TEST toxicity predictions showed that relative toxicities were ranked IN-KG433 > indoxacarb > IN-JT333 > IN-MK638 > IN-MF014. The toxicity of the degradation product IN-KG433 is higher than that of indoxacarb itself, and its maximum leaching rate is as high as 88.2%. It therefore transfers readily from processed tea to the tea infusion during the brewing process. These findings indicate the need to pay attention to the risk of metabolites and enantiomeric differences and provide new, comprehensive insight into the risk factors for indoxacarb in tea and are relevant to the study of other chiral pesticides., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

The ban imposed by the European Union on the use of neonicotinoids as sugar beet seed treatments was based on the exposure of bees to residues of neonicotinoids in pollen and nectar of succeeding crops. To address this concern, residues of thiamethoxam (TMX) and clothianidin (CTD) were analyzed in soil collected from fields planted in at least the previous year with thiamethoxam-treated sugar beet seed. This soil monitoring program was conducted at 94 sites across Germany in two separate years. In addition, a succeeding crop study assessed residues in soil, guttation fluid, pollen, and nectar sampled from untreated succeeding crops planted in the season after thiamethoxam seed-treated sugar beet at eight field sites across five countries. The overall mean residues observed in soil monitoring were 8.0 ± 0.5 µg TMX + CTD/kg in the season after the use of treated sugar beet seed. Residue values decreased with increasing time interval between the latest thiamethoxam or clothianidin application before sugar beet drilling and with lower application frequency. Residues were detected in guttation fluid (2.0-37.7 µg TMX/L); however, the risk to pollinators from this route of exposure is likely to be low, based on the reported levels of consumption. Residues of thiamethoxam and clothianidin in pollen and nectar sampled from the succeeding crops were detected at or below the limit of quantification (0.5-1 µg a.i./kg) in 86.7% of pollen and 98.6% of nectar samples and, unlike guttation fluid residues, were not correlated with measured soil residues. Residues in pollen and nectar are lower than reported sublethal adverse effect concentrations in studies with honeybee and bumble bee individuals and colonies fed only thiamethoxam-treated sucrose, and are lower than those reported to result in no effects in honeybees, bumble bees, and solitary bees foraging on seed-treated crops. Integr Environ Assess Manag 2022;18:709-721. © 2021 SYNGENTA. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC)., (© 2021 SYNGENTA. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).)

Spodoptera frugiperda (J.E. Smith) is a highly invasive noctuid pest first reported in northern Australia during early 2020. To document current status of resistance in S. frugiperda in Australia, insecticide toxicity was tested in field populations collected during the first year of establishment, between March 2020 and March 2021. Dose-response was measured by larval bioassay in 11 populations of S. frugiperda and a susceptible laboratory strain of Helicoverpa armigera. Emamectin benzoate was the most efficacious insecticide (LC50 0.023μg/ml) followed by chlorantraniliprole (LC50 0.055μg/ml), spinetoram (LC50 0.098μg/ml), spinosad (LC50 0.526μg/ml), and methoxyfenozide (1.413μg/ml). Indoxacarb was the least toxic selective insecticide on S. frugiperda (LC50 3.789μg/ml). Emamectin benzoate, chlorantraniliprole and methoxyfenozide were 2- to 7-fold less toxic on S. frugiperda compared with H. armigera while spinosyns were equally toxic on both species. Indoxacarb was 28-fold less toxic on S. frugiperda compared with H. armigera. There was decreased sensitivity to Group 1 insecticides and synthetic pyrethroids in S. frugiperda compared with H. armigera: toxicity was reduced up to 11-fold for methomyl, 56 to 199-fold for cyhalothrin, and 44 to 132-fold for alpha cypermethrin. Synergism bioassays with metabolic inhibitors suggest involvement of mixed function oxidase in pyrethroid resistance. Recommended diagnostic doses for emamectin benzoate, chlorantraniliprole, spinetoram, spinosad, methoxyfenozide and indoxacarb are 0.19, 1.0, 0.75, 6, 12 and 48μg/μl, respectively., Competing Interests: The authors have declared that no competing interests exist.

Dolutegravir (DTG) is currently one of the most used Integrase inhibitors (INI) in antiretroviral therapies (ARV) in both naïve and experienced people living with HIV (PLWHIV). We analyzed a multicenter cohort of PLWHIV, both naïve and experienced, starting an ARV including DTG. We enrolled 3775 PLWHIV: 2763 (73.2%) were males, with a median age of 50 years. During 9890.7 PYFU, we observed 930 discontinuations (9.4 per 100 PYFU). Estimated probabilities of maintaining DTG at three and five years were 75.1% and 67.2%, respectively. Treatment-naïve pts showed a lower probability of maintaining DTG at three and five years compared to treatment-experienced PLWHIV (log-rank p < 0.001). At a multivariate analysis, a longer time of virological suppression (aHR 0.994, p < 0.001) and having experienced a previous virological failure (aHR 0.788, p = 0.016) resulted protective against DTG discontinuation. Most discontinuations (84.0%) happened within the first 12 months of DTG initiation, in particular, 92.2% of discontinuations due to neuropsychiatric toxicity were observed in the first year. Our data confirm the overall good tolerability of DTG in clinical practice, with a low rate of discontinuations. CNS toxicity resulted the main reason for DTG discontinuation, with most related interruptions happening in the first year from DTG introduction.

The long-tailed silverfish Ctenolepisma longicaudatum (Lepismatidae: Zygentoma) is a nuisance problem in buildings and a major concern in museums, libraries and archives where it cause damage to historical and priceless items. We used laboratory bioassays and two field studies of infested buildings to evaluate spatial and temporal elements of a poisoned bait strategy. In both laboratory experiments and field studies, the efficiency of poisoned bait with indoxacarb as the active ingredient was significantly improved by placing many small bait droplets evenly distributed along all edges of the treated area compared to more clustered distributions. Extended duration of bait presence and removal of competing food sources improved the control effect significantly in the laboratory bioassays. Bait-treated populations also showed a significant decline in the number of eggs deposited and emergence of new nymphs. The study supports poisoned bait as an efficient and low risk approach against the long-tailed silverfish in which extended duration of bait presence, wide distribution of bait droplets in combination with sanitation was crucial for control in the infested premises., Competing Interests: The authors have declared that no competing interests exist.

Dolutegravir (DTG) is a first-line antiretroviral drug (ARV) used in combination therapy for the treatment of human immunodeficiency virus type-1 (HIV-1) infection. The drug is effective, safe, and well tolerated. Nonetheless, concerns have recently emerged for its usage in pregnant women or those of child-bearing age. Notably, DTG-based ARV regimens have been linked to birth defects seen as a consequence of periconceptional usages. To this end, uncovering an underlying mechanism for DTG-associated adverse fetal development outcomes has gained clinical and basic research interest. We now report that DTG inhibits matrix metalloproteinases (MMPs) activities that could affect fetal neurodevelopment. DTG is a broad-spectrum MMPs inhibitor and binds to Zn ++ at the enzyme's catalytic domain. Studies performed in pregnant mice show that DTG readily reaches the fetal central nervous system during gestation and inhibits MMP activity. Postnatal screenings of brain health in mice pups identified neuroinflammation and neuronal impairment. These abnormalities persist as a consequence of in utero DTG exposure. We conclude that DTG inhibition of MMPs activities during gestation has the potential to affect prenatal and postnatal neurodevelopment., (© 2021. The Author(s).)

The increasing use of insecticides, promoted by the intensification of agriculture, has raised concerns about their influence on the decline of bee colonies, which play a fundamental role in pollination. Thus, it is fundamental to elucidate the effects of insecticides on bees. This study investigated the damage caused by a sublethal concentration of thiamethoxam - TMX (0.0227 ng/μL of feed) in the head and midgut of Africanized Apis mellifera, by analyzing the enzymatic biomarkers, oxidative stress, and occurrence of lipid peroxidation. The data showed that the insecticide increased acetylcholinesterase activity (AChE) and glutathione-S-transferase (GST), whereas carboxylesterase (CaE3) activity decreased in the heads. Our results indicate that the antioxidant enzymes were less active in the head because only glutathione peroxidase (GPX) showed alterations. In the midgut, there were no alkaline phosphatase (ALP) or superoxide dismutase (SOD) responses and a decrease in the activity of CaE was observed. Otherwise, there was an increase in GPX, and the TBARS (thiobarbituric acid reactive substances) assay also showed differences in the midgut. The TBARS (thiobarbituric acid reactive substances) assay also showed differences in the midgut. The results showed enzymes such as CaE3, GST, AChE, ALP, SOD, and GPX, as well as the TBARS assay, are useful biomarkers on bees. They may be used in combination as a promising tool for characterizing bee exposure to insecticides., (Copyright © 2021. Published by Elsevier Inc.)

The xenobiotic transcription factor cap 'n' collar isoform C (CncC) is considered the central regulator of antioxidant and detoxification genes. Previous research indicated that CncC regulates three-phase enzymes responsible for insecticide resistance. In this study, the SlituCncC gene from Spodoptera litura was obtained and characterized. Quantitative polymerase chain reaction (qPCR) analysis showed that SlituCncC was expressed in all developmental stages and tissues, but was highly expressed in 3rd- and 4th-instar larvae, and in the Malpighian tubule, fat body, and midgut. In addition, SlituCncC was up-regulated and more highly induced with indoxacarb treatment in the indoxacarb-resistant strains compared with the susceptible strain. RNA interference-mediated gene silencing of SlituCncC significantly increased mortality of S. litura when exposed to indoxacarb. Furthermore, comparative transcriptome analysis showed that 842 genes were down-regulated and 127 genes were up-regulated in SlituCncC knockdown S. litura. Further analysis indicated that 18 three-phase enzymes were identified in the down-regulated genes, of which seven were associated with indoxacarb resistance in S. litura. qPCR analysis confirmed that expression of six of these seven genes was consistent with RNA sequencing data. All six detoxification genes were induced by indoxacarb, and the expression patterns were similar to that of SlituCncC. Finally, the CncC-Maf binding site was predicted in all six gene promoters. This study indicates that the transcription factor SlituCncC may regulate multiple detoxification genes that mediate indoxacarb resistance in S. litura., (© 2020 Institute of Zoology, Chinese Academy of Sciences.)

Emerging and re-emerging viruses periodically cause outbreaks and epidemics all over the world, eventually leading to global events such as the current pandemic of the novel SARS-CoV-2 coronavirus infection COVID-19. Therefore, an urgent need for novel antivirals is crystal clear. Here we present the synthesis and evaluation of an antiviral activity of phenoxazine-based nucleoside analogs divided into three groups: (1) 8-alkoxy-substituted, (2) acyclic, and (3) carbocyclic. The antiviral activity was assessed against a structurally and phylogenetically diverse panel of RNA and DNA viruses from 25 species. Four compounds (11a-c, 12c) inhibited 4 DNA/RNA viruses with EC 50  ≤ 20 μM. Toxicity of the compounds for the cell lines used for virus cultivation was negligible in most cases. In addition, previously reported and newly synthesized phenoxazine derivatives were evaluated against SARS-CoV-2, and some of them showed promising inhibition of reproduction with EC 50 values in low micromolar range, although accompanied by commensurate cytotoxicity., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Masson SAS. All rights reserved.)

Background: The utilization efficiency of conventional insecticides is comparatively low in agricultural production, which leads to their excessive application and environmental pollution. Insecticide nanometerization by polymers and polymeric materials has advantages, particularly increased utilization efficiency and reduced insecticide application., Results: To increase the utilization efficiency of insecticides, a star polycation (SPc) was selected as a drug carrier that could be complexed with thiamethoxam through electrostatic interaction. Formation of the complex decreased the particle size of thiamethoxam from 575.77 to 116.16 nm in aqueous solution. Plant uptake of SPc-delivered thiamethoxam was increased 1.69-1.84 times compared with thiamethoxam alone. Nano-sized thiamethoxam/SPc complexes showed enhanced contact and stomach toxicity against green peach aphids., Conclusion: SPc is a promising insecticide adjuvant for insecticide nanometerization, and is beneficial in improving insecticidal activity and decreasing the application amounts and application rates of conventional insecticides. © 2020 Society of Chemical Industry., (© 2020 Society of Chemical Industry.)

The diamondback moth, Plutella xylostella (Linnaeus, 1758), is one of the main pests of brassicas, and various insecticides, such as indoxacarb, are used to control it. However, frequent insecticide applications favor the selection of resistant individuals. Thus, the residual and sublethal effects of indoxacarb in two populations of P. xylostella, one collected in the field (FP) and one from the laboratory (LP), were evaluated and compared. The objective of this research was to investigate the toxicity of indoxacarb at residual and sublethal levels in a field population of P. xylostella from Brazil and a population from the laboratory. Leaf-dip bioassays showed high toxicity, with LC50 values after 48 h of 3.7 and 6.9 mg/liter for the LP and FP, respectively. Sublethal effects were indicated by significant reduction in the survival of larvae, pupae, and offspring. There was an increase in foliar consumption and a decrease in adult survival in the LP, and a decrease in fecundity in the FP. For the LP and FP population, the mean values for R0, rm, and λ for the control treatment were significantly higher than for the treatment groups (CL15 and CL25). Exposure of larvae to sublethal indoxacarb concentrations significantly reduced larval and pupal survival. Larval and pupal survival decreased as the indoxacarb concentration increased. Fecundity was significantly lower for the FP at LC15 (96.2 eggs per female) and LC25 (69.2 eggs per female) concentrations compared with the other treatments., (© The Author(s) 2020. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The high mortality rate and increasing prevalence of resistant Mtb are the major concerns for the Tuberculosis (TB) treatment in this century. To curtail the prevalence of resistant Mtb, we have prepared 1,3-oxazine-2-one based dual targeted molecules. Compound 67 and 68 were found to be equally active against replicating and non-replicatiing form of Mtb (MIC MABA 3.48 and 2.97 μg/ml; MIC LORA 2.94 and 2.15 μg/ml respectively). They had found to suppress the biosynthesis of alfa, methoxy and keto-mycolate completely, as well as inhibit enzymatic activity of MenG (IC 50  = 9.11 and 6.25 μg/ml respectively for H37Ra; IC 50  = 11.76 and 10.88 μg/ml respectively for M smegmatis)., Competing Interests: Declaration of competing interest There is no conflict of interest with others., (Copyright © 2020 Elsevier Masson SAS. All rights reserved.)

Resistance to commonly used grain protectants and fumigants in stored product insect pests necessitates the need to explore alternative substances. Indoxacarb is a reduced-risk oxadiazine insecticide that is generally used in field crops, but there are limited reports of its susceptibility in stored insect pests. The objective of this study was to determine susceptibility to indoxacarb in laboratory and field strains of five major stored product insects: Rhyzopertha dominica (Fabricius), Sitophilus zeamais (Motschulsky), S. oryzae (Linnaeus), Tribolium castaneum (Herbst), and Oryzaephilus surinamensis (L.), using dose-mortality bioassays on wheat grains. In most of the cases, the susceptibility of laboratory strains of all the studied pests were significantly higher than the corresponding field strains. The LD 50 and LD 99 values (mg a.i./kg of grains) of field strains ranged from 0.13 to 0.38, and 3.44 to 24.76, respectively (for R. dominica), 0.26 to 0.55, and 5.26 to 19.37, respectively (for S. oryzae), 0.41 to 1.01, and 13.11 to 22.46, respectively (for S. zeamais), 0.67 to 1.37, and 15.43 to 43.44, respectively (for T. castaneum), and 0.52 to 0.92, and 18.06 to 61.63, respectively (for O. surinamensis). Synergism bioassays implementing piperonyl butoxide or S,S,S-tributyl phosphorotrithioate along with indoxacarb on selected field strains revealed enhanced susceptibility to indoxacarb. The study demonstrates relative susceptibility to indoxacarb in major stored product insects. Synergism results support the probability of metabolic-based mechanisms responsible for mitigating indoxacarb toxicity. The results might be helpful for monitoring future variation in susceptibility to indoxacarb in the selected insect species and for setting field rates., Competing Interests: Declaration of competing interest The author declares no conflict of interest., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Despite the availability of modern antiretroviral therapy (ART), neurocognitive impairment persists among some persons with HIV (PWH). We investigated the role of exposure to four major classes of ARTs in neurocognitive impairment in PWH. A single-site cohort of 343 PWH was recruited. Lifetime ART medication history was obtained from medical health records. We evaluated the role of ART exposure as a predictor of neurocognitive impairment using univariate analyses and machine learning, while accounting for potential effects of demographic, clinical, and comorbidity-related risk factors. Out of a total of 26 tested variables, two random forest analyses identified the most important characteristics of a neurocognitively impaired group (N = 59): Compared with a neurocognitively high-performing group (N = 132; F 1 -score = 0.79), we uncovered 13 important risk factors; compared with an intermediate-performing group (N = 152; F 1 -score = 0.75), 16 risk factors emerged. Longer lifetime ART exposure, especially to integrase inhibitors, was one of the most important predictors of neurocognitive impairment in both analyses (rank 2 of 13 and rank 4 of 16, respectively), superseding effects of age (rank 11/13, rank 15/16) and HIV duration (rank 13/13, rank 16/16). Concerning specific integrase inhibitors, the impaired group had significantly longer dolutegravir exposure (p = 0.011) compared with the high-performing group (p = 0.012; trend compared with the intermediate group p = 0.063). A longer duration to integrase inhibitor intake was negatively related to cognition in this cohort. Our findings suggest that possible cognitive complications of long-term exposure to integrase inhibitors, in particular dolutegravir, should be closely monitored in PWH.

The lacewing, Chrysoperla sinica, is an important predatory insect, which plays an important role in the integrated pest management of agroforestry pests. However, the extensive use of insecticides negatively affects C. sinica. The acute toxicity, risk level, and, sublethal effects on growth and production, predation ability, protective enzyme activity and genotoxicity of four insecticides: indoxacarb, emamectin benzoate, imidacloprid and lambda-cyhalothrin to C. sinica were studied. The results showed that all four insecticides had lethal toxicity to larvae of C. sinica. Among them, emamectin benzoate had the highest toxicity with LC 50 value of 7.41 mg/L. The insecticides also had different effects on the growth and reproduction of C. sinica, of which lambda-cyhalothrin had the greatest impacts. Even at a very low LC 1 concentration (3.37 mg/L), it had strong impacts on the growth, reproduction and predatory ability of C. sinica. The four insecticides also caused a decrease in the predatory ability of the lacewing, of which lambda-cyhalothrin had the greatest effect. During the larval stage, the activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) were significantly decreased by the four insecticides. At the pupal and adult stages, the effects of the four insecticides on the activities of protective enzymes were different, and the activities of SOD, CAT and POD decreased or increased. Indoxacarb and lambda-cyhalothrin exposure induced DNA damage in the haemocytes of C. sinica and produced obvious genotoxicity. These results provide important scientific basis for the rational use of these insecticides and the protection and utilization of lacewing., Competing Interests: Declaration of competing interest The authors declare that they have no potential conflict of interest in relation to the study in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Light-harvesting systems are an important way for capturing, transferring and utilizing light energy. It remains a key challenge to develop highly efficient artificial light-harvesting systems. Herein, we report a supramolecular co-assembly based on lower-rim dodecyl-modified sulfonatocalix[4]arene (SC4AD) and naphthyl-1,8-diphenyl pyridinium derivative (NPS) as a light-harvesting platform. NPS as a donor shows significant aggregation induced emission enhancement (AIEE) after assembling with SC4AD. Upon introduction of Nile blue (NiB) as an acceptor into the NPS-SC4AD co-assembly, the light-harvesting system becomes near-infrared (NIR) emissive (675 nm). Importantly, the NIR emitting NPS-SC4AD-NiB system exhibits an ultrahigh antenna effect (33.1) at a high donor/acceptor ratio (250:1). By co-staining PC-3 cells with a Golgi staining reagent, NBD C 6 -ceramide, NIR imaging in the Golgi apparatus has been demonstrated using these NIR emissive nanoparticles., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A novel hypochlorous-acid-selective signaling probe based on the carbonodithioate derivative of resorufin (RT-1) was developed. Probe RT-1 showed prominent colorimetric and turn-on type fluorescence signaling behavior exclusively toward hypochlorous acid, induced by oxidative hydrolysis, to regenerate resorufin dye. Hypochlorous acid signaling was not affected by the presence of common metal ions and anions as background, except for the redox active bromide and iodide anions. The detection limit of RT-1 for hypochlorous acid was found to be 2.18 × 10-9 M (0.11 ppb), and the signaling was completed within 3 min. It was also confirmed that hypochlorous acid signaling by the carbonodithioate-based probe RT-1 was superior to that of the closely related carbonothioate derivative RT-2. This was rationalized by density functional theory calculations, which demonstrated that the C[double bond, length as m-dash]S sulfur atom of the former is more negatively charged than that of the latter. Finally, as a biological application of the probe, visualization of hypochlorous acid in RAW 264.7 murine macrophages and HeLa cells was successfully conducted to detect the cellular response to hypochlorous acid.

Studies of amyloid proteins have gradually become a hot topic. Nevertheless, very few effective drugs and treatments is available to cope with amyloid diseases. New molecules that can inhibit the protein fibrillation are highly anticipated. Insulin is one of the popular amyloid protein research models. On the other hand, resazurin and resorufin are widely known as a redox pair. We describes here an unexpected finding that resazurin plays a role in modulating insulin fibrillation, whereas resorufin doesn't. We hypothesize that the positively charged insulin at low pH can combine with the negatively charged resazurin due to electrostatic interaction, through which resazurin inhibited the process of insulin fibrillation. This effect was characterized and verified by using various biochemical, spectroscopic and imaging tools. This inhibition of this biocompatible dye can be achieved at various stages of fibrillation, suggesting the toxicity of the protein fibrils can be eliminated by using resazurin., (Copyright © 2019. Published by Elsevier B.V.)

Thiophenols as high toxic environmental pollutants are poisonous for animals and aquatic organisms. Therefore, it is indispensable to monitor thiophenols in the environment. Herein, a novel near-infrared fluorescent probe was developed for the detection of thiophenols, which was easily prepared by one-step coupling of 2,4-dinitrobenzenesulfonyl chloride with Nile blue. The probe showed a significant near infrared (∼675 nm) fluorescence "turn-on" response to thiophenols with some good features including chromogenic reaction, high sensitivity and selectivity, fast response, near-infrared emission along with low detection limit (1.8 nM). The probe was employed to rapidly and visually determine thiophenols in several industrial wastewaters with good recoveries (90-110%). Moreover, this probe has been demonstrated good capability for imaging thiophenol in HeLa cells., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Indoxacarb, a commercialized oxadiazine insecticide, nearly irreversibly blocks open/inactivated, but not resting sodium channels. The structure-activity relationships showed that the substituents at the position of the chiral atom in the oxadiazine ring are very important to the biological activity of oxadiazine insecticide. Here we synthesized a series of tricyclic oxadiazine 4a-methyl ester derivatives. The chiral atom in the oxadiazine ring has been epimerized and substituted with either pyrethric acid or cinnamic acid derivatives. Benzene ring in the tricyclic moiety was substituted with a chlorine, fluorine, or bromine atom, and nitrogen-linked benzene ring was substituted with a trifluoromethyl or trifluoromethoxy group. Toxicity of these compounds against Spodoptera litura F. was evaluated. Diastereoisomers of most toxic compounds J7 and J9 with pyrethric acid moiety were separated by flash column chromatography. The more polar diastereoisomers, J7-L-Rf and J9-L-Rf, and compounds J24 and J26 with cinnamic acid moiety exhibited highest insecticidal activities. We further used Monte Carlo energy minimizations to dock compound J7 and J24 in the NavMs-based homology model of the open cockroach sodium channel. In the low-energy binding modes, the compound interacted with residues in the inner pore and domain interfaces, which previously were proposed to contribute to receptors of pyrethroids and sodium channel blocker insecticides. Our results define compound J7 and J24 as a potentially useful optimized hit for the development of multiple sites sodium channel blocker or modulator.

Background: Basic blue 3 is a promising anti-malarial lead compound based on the π-delocalized lipophilic cation hypothesis. Its derivatives with nitrogen atoms bonded to carbon atoms at the 3- and 7-positions on the phenoxazine ring were previously shown to exert potent antiprotozoal activity against Plasmodium falciparum, Trypanosoma cruzi, Trypanosoma brucei rhodesiense, and Leishmania donovani parasites in vitro. However, compounds with nitrogen modification at the 10-position on the phenoxazine ring were not evaluated., Methods: Six acylphenoxazine derivatives (ITT-001 to 006) with nitrogen modification at the 10-position on the phenoxazine ring, which were synthesized from basic blue 3, were characterized and evaluated for anti-malarial activity in vitro with an automated haematology analyzer (XN-30) and light microscopy. Intensity of self-fluorescence was measured using a fluorometer. Localization of basic blue 3 was observed by fluorescence microscopy. Cytotoxicity was evaluated using human cell lines, HEK293T and HepG2 cells. Finally, anti-malarial activity was evaluated in a rodent malaria model., Results: All the six derivatives showed anti-malarial efficacy even against chloroquine-, pyrimethamine-, and artemisinin-resistant field isolates similar to the sensitive strains and isolates in vitro. The efficacy of basic blue 3 was the strongest, followed by that of ITT-001 to 004 and 006, while that of ITT-005 was the weakest. Basic blue 3 showed strong self-fluorescence, whereas ITT derivatives had five- to tenfold lower intensity than that of basic blue 3, which was shown by fluorescence microscopy to be selectively accumulated in the plasmodial cytoplasm. In contrast, ITT-003, 004, and 006 exhibited the lowest cytotoxicity in HEK293T and HepG2 cells in vitro and the highest selectivity between anti-malarial activity and cytotoxicity. The in vivo anti-malarial assay indicated that oral administration of ITT-004 was the most effective against the rodent malaria parasite, Plasmodium berghei NK65 strain., Conclusions: The six ITT derivatives were effective against chloroquine- and pyrimethamine-resistant strains and artemisinin-resistant field isolates as well as the sensitive ones. Among them, ITT-004, which had high anti-malarial activity and low cytotoxicity in vitro and in vivo, is a promising anti-malarial lead compound.

Biothiols, including cysteine (Cys), homocysteine (Hcy), glutathione (GSH) and H 2 S, play important roles in human physiological processes. However, it is a great difficulty to distinguish biothiols from each other because of their similar chemical properties. Based on Nile red, we have designed and synthesized a near-infrared fluorescent probe for discriminating Cys/Hcy from GSH/H 2 S by a dual-channel detection method. Using an ether bond, near-infrared Nile red was attached to 7-nitrobenzofurazan to construct the probe. Due to the photo-induced electron transfer, the probe showed almost no fluorescence from the green to red emission band. But upon the addition of Cys (0-150 μM) or Hcy (0-200 μM), the probe exhibited a noteworthy fluorescence "turn-on" signal in two unique emission bands (Green and Red) with a fast response (within 30 min). In contrast, the probe displayed an increase in fluorescence only in the red channel when encountering GSH (0-70 μM) or H 2 S (0-50 μM), and GSH/H 2 S could be tested respectively by different response time. The limit of detection was calculated to be 0.09 μM (Cys), 0.30 μM (Hcy), 0.24 μM (GSH), and 0.04 μM (H 2 S), respectively (based on S/N = 3). The desirable dual-channel detection could be achieved in serum samples and living cells. Moreover, the probe could be applied for bioimaging in mice, which indicated its potential application in the clinic.

The microalgal cell wall is a natural barrier that limits the efficiency of gene delivery in algae genetic engineering. Here, we report the role of hard-uptake nanoparticles (huNPs) in microalgae cell electroporation to enhance the delivery of genes in Chlamydomonas reinhardtii. This role can be divided into two categories: (i) a 'transient state' for short-term behavior under confocal visualization and (ii) a 'steady state' for long-term behavior in cell culture. First, the 'transient' role of gene-huNP complexes was investigated after washing for clear confocal imaging to observe the location of huNPs after electroporation. Second, the 'steady-state' role of the gene-huNP complexes was examined after electroporation by transferring cells to a fresh, medium-rich culture environment without washing to obtain a stable cell culture. For selection of the huNPs, we used two types of nanoparticles (NPs, 250 nm and 530 nm) larger than the threshold size of electroporation uptake to avoid unwanted endocytic uptake of NPs. In the transient state, the visualization results indicate that gene-NP (250 nm) complexes were positioned on the cells and helped to deliver more genes than did the 530 nm NPs. In the steady state, the gene-NP (530 nm) complexes helped stably deliver more genes to the cells by precipitation of NPs due to gravity. We believe that these findings illustrate how gene-NP complexes function in microalgae cell electroporation and could help set up a protocol for enhanced microalgae applications associated with NPs such as environmental waste removal and biofuel production.

Spinosad and indoxacarb are two relatively new insecticides mainly used in agriculture to control insect pests. However, at their current application rates, non-target aquatic insect species may also be impacted. In this study, larvae of the non-biting midge Chironomus riparius were exposed in the laboratory to both insecticides and their effects evaluated at the organismal level, using standard ecotoxicological tests, and at the biochemical level, by monitoring specific oxidative stress, neuronal, and energy metabolism biomarkers. Chronic exposure to both insecticides compromised growth and emergence of C. riparius. Short-term exposures revealed alterations at biochemical level that might be related to the toxicological targets of both insecticides. Growth and development time were the most sensitive endpoints at individual level for both pesticides, while at the biochemical level, the electron transport system activity was the most sensitive biomarker for spinosad exposure, suggesting an increase in energy demands associated with the activation of defense mechanisms. Glutathione-S-transferase was the most sensitive biomarker for indoxacarb exposure, underlining the role of this enzyme in the detoxification of indoxacarb. Additionally, changes in lactate dehydrogenase and glutathione peroxidase activities were observed for both insecticides, and evidences of oxidative damage were found for spinosad. This study contributes to the growing knowledge on sublethal effects of novel insecticides on non-target aquatic invertebrates and strengthens the usefulness of biochemical biomarkers to support the interpretation of their potentially deleterious effects on aquatic insects near agricultural fields., (Copyright © 2019 Elsevier B.V. All rights reserved.)

As the oxidative metabolites of the endogenous gasotransmitter H2S, H2Sn have attracted ever-increasing attention in the field of biomedical research due to their vital functions in biological systems. Herein, we report a resorufin-based "turn-on" probe for H2Sn sensing. An SNAr substitution-intramolecular cyclization cascade reaction was used in this probe for detecting exogenous and endogenous H2Sn. The detection process could be monitored using UV-Vis and fluorescence spectroscopy and the naked eye. The emission response of the probe towards H2Sn presented a good linear relationship in the 0-50 μM concentration range, and the LOD of this probe was 24 nM. The probe was used successfully to visualize endogenous H2Sn generated in the RAW 246.7 cells under external stimulation.

The hepatic cytochrome p450 enzymes 1 A, 2A19 and 2E1 is very important for the elimination of skatole from the body of pigs. Impaired skatole metabolism, results in skatole accumulation, which give rise to off flavor of the meat. Several metabolites of skatole has been identified, however the role of these metabolites in the inhibition of the skatole metabolizing enzymes are not documented. Using microsomes from pigs and fish, we determined the ability of several skatole metabolites to inhibit CYP1 A, CYP2A19 and CYP2E1 dependent activity. Our results show that 2-aminoacetophenone is an inhibitor of porcine CYP2A19 and CYP2E1 activity, but not the piscine orthologues. In conclusion, there is species specific differences in the inhibition of CYP1 A and CYP2A19 dependent metabolism of probe substrates. This is relevant to the evaluation of different model systems and to the reduction of off flavor of meat., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The aim of the present study was to investigate the effects of chronic exposure of common carp (Cyprinus carpio) to indoxacarb on immune, antioxidant and stress gene expression. After 21 days exposure to 0, 0.75, 1.5 and 3 ppm indoxacarb, expression of IL-1β, IL-8, IL-10, TNF-α, IFN-γ, SOD, CAT, HSP70, IGF-I and IGF-II were assessed in liver, kidney and gills. In general, exposure to low concentration of indoxacarb increased inflammatory cytokine gene expression (IL-1β, IL-8, IL-10, TNF-α and IFN-γ) and inhibits inflammatory cytokines' expression at higher concentrations. The assessment of antioxidant gene expression (SOD and CAT) in different organs indicate that they were increased by low concentrations of indoxacarb to deal with primary oxidative situation. However, higher concentrations of indoxacarb caused reduction in oxidative gene expression. IGF genes expression in liver significantly increased at a concentration of 0.75 ppm treatment, then it decreased at 1.5 ppm indoxacarb and increased again by increasing in the indoxacarb concentration to 3 ppm. The expression of HSP70 in kidney showed a significant elevation in 0.75 and 1.5 ppm treatments compared with 3 ppm treatment and the control group. The expression of this gene in liver was significantly increased in 1.5 and 3 ppm treatments. The same pattern of expression was also observed in gill. Overall, indoxacarb exposure affects common carp health at transcription levels. Changes in the genes expression generally suggest that indoxacarb exposure led to interference in inflammation, oxidative stress and tissue damage., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Neonicotinoids have recently been demonstrated to cause direct negative impacts on birds from North America and Europe. To further understand the impact of these compounds on bird species and to improve risk assessment capacities, the current study determined the acute toxicities of imidacloprid, clothianidin, and thiamethoxam formulations on South American eared doves (Zenaida auriculata). Insecticides were administered by gavage to adult doves to determine median lethal doses (LD50) according to a standardized sequential procedure. The acute toxicity of formulated imidacloprid (LD50=59mg active ingredient, a.i./kg body weight, b.w.) was much higher than that of the tested formulations of clothianidin (LD50=4248mga.i./kg b.w.) and thiamethoxam (LD50=4366mga.i./kg b.w.). Imidacloprid also differed from the other two neonicotinoids in terms of the onset and intensity of intoxication signs and the times of death and recovery. All three insecticides induced a reduction in food consumption that led to body weight loss. An average weight dove of 127g would obtain a dose equivalent to the LD50 of imidacloprid by consuming 1.7g of treated sorghum seeds. As eared doves offered non-treated sorghum seeds 5h per day consumed on average 6.4±1.8g (mean±S.D.), it is concluded that these doves could feasibly be exposed to lethal doses in the field. This work is the first to describe intoxication signs and report oral neonicotinoid LD50s in a wild South-American bird species., (Copyright © 2018. Published by Elsevier B.V.)

In this study, the bioactivities of binary mixtures of organosilicone surfactants and indoxacarb against two Lepidopteran pests were investigated along with their environmental risks. All of the tested organosilicone surfactants had obvious synergistic effects on the contact toxicity of indoxacarb against Spodoptera exigua and Agrotis ipsilon. However, all of the organosilicone surfactants exhibited certain antagonism for indoxacarb against S. exigua in terms of stomach & contact toxicity; both Silwet-408 and Silwet-806 exhibited additivity against A. ipsilon, whereas Silwet-618 and Silwet-DRS-60 exhibited synergism and slight antagonism, respectively. All of the tested chemicals were highly toxic to Daphnia magna, among which Silwet-DRS-60 had the lowest acute toxicity (EC 50 of 94.91 μg/L). However, these chemicals were less toxic to Brachydanio rerio. Silwet-DRS-60 had a low toxicity to B. rerio, while Silwet-408, Silwet-806 and Silwet-618 were moderately toxic to B. rerio. For the joint toxicity evaluation of organosilicone surfactants and indoxacarb to D. magna and B. rerio, the additive index method, concentration addition method and toxicity unit method were robust in judging synergism or antagonism, whereas other methods were more conservative; the V-value method and equilibrium curve method exhibited high robustness and viability in evaluating the combined effects of binary mixtures. Overall, we should carefully select organosilicone surfactants for premixed or tank-mixed pesticides in agriculture to obtain a balance between synergistic effects on pests and environmental risks., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

When any living organism is frequently exposed to any drugs or toxic substances, they evolve different detoxification mechanism to confront with toxicants during absorption and metabolism. Likewise, the insects have evolved detoxification mechanisms as they are frequently exposed to different toxic secondary plant metabolites and commercial insecticides. ABC transporter superfamily is one of the largest and ubiquitous group of proteins which play an important role in phase III of the detoxification process. However, knowledge about this gene family remains largely unknown. To help fill this gap, we have identified a total of 54 ABC transporters in the Helicoverpa armigera genome which are classified into eight subfamilies (A-H) by phylogenetic analysis. The temporal and spatial expression profiles of these 54 ABC transporters throughout H. armigera development stages and seven tissues and their responses to five different insecticides, were investigated using RNA-seq analysis. Furthermore, the mRNA expression of eight selected genes in different tissues and six genes responses to insecticides were confirmed by the quantitative real-time PCR (RT-qPCR). Moreover, H. armigera become more sensitive to abamectin and indoxacarb when P-gp was inhibited. These results provide a foundation for further studies of ABCs in H. armigera., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Thiamethoxam is a neonicotinoid insecticide used widely in agriculture to control a broad spectrum of insect pests. To assess potential risks from this compound to non-target aquatic organisms, an outdoor mesocosm study was performed. Mesocosms (1300 L) were treated once with a formulated product with the active substance (a.s.) thiamethoxam at nominal concentrations of 1 (n = 3), 3 (n = 3), 10 (n = 4), 30 (n = 4), and 100 (n = 2) μg a.s./L, plus untreated controls (n = 4). Primary producers (phytoplankton), zooplankton, and macroinvertebrates were monitored for up to 93 days following treatment. Thiamethoxam was observed to have a water column dissipation half-life (DT50) of ≤1.6-5.2 days in the mesocosms. Community-based principal response curve analysis detected no treatment effects for phytoplankton, zooplankton, emergent insects, and macroinvertebrates, indicating a lack of direct and indirect effects. A number of statistically significant differences from controls were detected for individual phytoplankton and zooplankton species abundances, but these were not considered to be treatment-related due to their transient nature and lack of concentration-response. After application of 30 μg a.s./L, slight temporary effects on Asellus aquaticus could not be excluded. At 100 μg a.s./L, there was an effect with no clear recovery of Asellus observed, likely due to their inability to recolonize these isolated test systems. A statistically significant but transient reduction in the emergence of chironomids by day 23 at the 100 μg a.s./L treatment was observed and possibly related to direct toxicity from thiamethoxam on larval stages. Therefore, a conservative study specific No Observed Ecological Adverse Effect Concentration (NOEAEC) is proposed to be 30 μg a.s./L. Overall, based on current concentrations of thiamethoxam detected in North American surface waters (typically <0.4 μg/L), there is low likelihood of direct or indirect effects from a pulsed exposure on primary producers, zooplankton, and macroinvertebrates, including insects, as monitored in this study., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Widespread agricultural use of neonicotinoid insecticides has resulted in frequent detection of mixtures of these compounds in global surface waters. Recent evidence suggests that neonicotinoid mixtures can elicit synergistic toxicity in aquatic insects under acute exposure conditions, however this has not been validated for longer exposures more commonly encountered in the environment. Therefore, we aimed to characterize the chronic (28-day) toxicity of imidacloprid, clothianidin, and thiamethoxam mixtures under different doses and mixture ratios to determine if the assumption of synergistic toxicity would hold under more environmentally realistic exposure settings. The sensitive aquatic insect Chironomus dilutus was used as a representative test species, and successful emergence was used as a chronic endpoint. Applying the MIXTOX modeling approach, predictive parametric models were fitted using single-compound toxicity data and statistically compared to observed toxicity in subsequent mixture tests. Imidacloprid-clothianidin, clothianidin-thiamethoxam and imidacloprid-clothianidin-thiamethoxam mixtures did not significantly deviate from concentration-additive toxicity. However, the cumulative toxicity of the imidacloprid-thiamethoxam mixture deviated from the concentration-additive reference model, displaying dose-ratio dependent synergism and resulting in up to a 10% greater reduction in emergence from that predicted by concentration addition. Furthermore, exposure to select neonicotinoid mixtures above 1.0 toxic unit tended to shift sex-ratios toward more male-dominated populations. Results indicate that, similar to acute exposures, the general assumption of joint additivity cannot adequately describe chronic cumulative toxicity of all neonicotinoid mixtures. Indeed, our observations of weak synergism and sex-ratio shifts elicited by some mixture combinations should be considered in water quality guideline development and environmental risk assessment practices for neonicotinoid insecticides, and explored in further investigations of the effects of neonicotinoid mixtures on aquatic communities., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Systematic evaluation of the metabolism, distribution, and effect of thiamethoxam in Mongolian racerunner ( Eremias argus) was carried out after oral exposure. HPLC equipped with Q Exactive focus was used for identification and concentration analysis of thiamethoxam and its metabolites. Percutaneous and urine excretions were the primary ways for the elimination of thiamethoxam and its metabolites, and the limiting factor was urine output. Demethylated thiamethoxam and clothianidin were the main metabolites of thiamethoxam in lizards. CYP3A4, CYP3A7, and CYP2C9 played a crucial role in the metabolism process. Aldehyde oxidase only dominated the nitro-reduction process of demethylated thiamethoxam and clothianidin. Glutathione S-transferase might be related to the clearance process of thiamethoxam and its metabolites. The findings indicated that thiamethoxam might pose potential carcinogenic and hepatic injury risk to lizards. The results enrich and supplement the knowledge of the environmental fate of thiamethoxam in reptiles.

Neonicotinoid insecticides are environmentally persistent and highly water-soluble, and thus are prone to leaching into surface waters where they may negatively affect non-target aquatic insects. Most of the research to date has focused on imidacloprid, and few data are available regarding the effects of other neonicotinoids or their proposed replacements (butenolide insecticides). The objective of this study was to assess the toxicity of six neonicotinoids (imidacloprid, thiamethoxam, acetamiprid, clothianidin, thiacloprid, and dinotefuran) and one butenolide (flupyradifurone) to Hexagenia spp. (mayfly larvae). Acute (96-h), water-only tests were conducted, and survival and behaviour (number of surviving mayflies inhabiting artificial burrows) were assessed. Acute sublethal tests were also conducted with imidacloprid, acetamiprid, and thiacloprid, and in addition to survival and behaviour, mobility (ability to burrow into sediment) and recovery (survival and growth following 21 d in clean sediment) were measured. Sublethal effects occurred at much lower concentrations than survival: 96-h LC50s ranged from 780 μg/L (acetamiprid) to >10,000 μg/L (dinotefuran), whereas 96-h EC50s ranged from 4.0 μg/L (acetamiprid) to 630 μg/L (thiamethoxam). Flupyradifurone was intermediate in toxicity, with a 96-h LC50 of 2000 μg/L and a 96-h EC50 of 81 μg/L. Behaviour and mobility were impaired significantly and to a similar degree in sublethal exposures to 10 μg/L imidacloprid, acetamiprid, and thiacloprid, and survival and growth following the recovery period were significantly lower in mayflies exposed to 10 μg/L acetamiprid and thiacloprid, respectively. A suite of effects on mayfly swimming behaviour/ability and respiration were also observed, but not quantified, following exposures to imidacloprid, acetamiprid, and thiacloprid at 1 μg/L and higher. Imidacloprid concentrations measured in North American surface waters have been found to meet or exceed those causing toxicity to Hexagenia, indicating that environmental concentrations may adversely affect Hexagenia and similarly sensitive non-target aquatic species., (Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.)

Neonicotinoid insecticides (NIs) have recently been recognized as co-factors in the decline of honeybee colonies because most neonicotinoids are systemic and can transfer into the pollen and nectar of many pollinated crops. In this study, we collected pollen, nectar and leaves from a cotton crop treated with imidacloprid and thiamethoxam to measure the residue levels of these two NIs at different application doses during the flowering period. Then, the residual data were used to assess the risk posed by the systemic insecticides to honeybees following mandated methods published by the European Food Safety Authority (EFSA), and a highly toxic risk to honeybees was highlighted. Imidacloprid was found in both pollen and nectar samples, whereas thiamethoxam was found in 90% of pollen samples and over 60% of nectar samples. Analysis of the pollen and nectar revealed residual amounts of imidacloprid ranging from 1.61 to 64.58 ng g -1 in the pollen and from not detected (ND) to 1.769 ng g -1 in the nectar. By comparison, the thiamethoxam concentrations in pollen and nectar ranged from ND to 14.521 ng g -1 and from ND to 4.285 ng g -1 , respectively. The results of this study provide information on the transfer of two NIs from seed treatment to areas of the plant and provides an understanding of the potential exposure of the bee and other pollinators to systemic insecticides., (Copyright © 2018 Elsevier Ltd. All rights reserved.)