Emamectin benzoate induces ROS-mediated DNA damage and apoptosis in Trichoplusia Tn5B1-4 cells

Pumpkin seed oil: a comprehensive review of extraction methods, nutritional constituents, and health benefits

Pumpkin seed oil (PSO), a rich source of nutrients, is extracted from the seeds of different pumpkin varieties for food and medicines. This article aims to provide an evidence-based review of the literature and to explore the extraction technologies, nutritional properties, and biological activity of PSO. From previous literature, PSO contains a large proportion of unsaturated fatty acids, with linoleic acid as the main component, and an amount of tocopherol, phytosterol, and phenolic acids. Some differences in the yield, composition, and physicochemical properties of PSO can be associated with the pumpkin's cultivars and the extraction methods. Some novel technologies involved in supercritical fluid extraction, enzyme-assisted aqueous extraction, and ultrasound-assisted extraction have been replacing the conventional technologies gradually as promising methods for the safe, non-polluting, and effective recovery of PSO. This healthy vegetable oil was reported by several in vitro and in vivo studies to have potential protective roles in oxidative stress, inflammation, cancer, and cardiovascular diseases. © 2023 Society of Chemical Industry.

Involvement of Glutamate Cysteine Ligase Genes in Tolerance to Emamectin Benzoate in Spodoptera frugiperda and Their Putative Regulatory Mechanisms

As the rate-limiting enzyme in de novo Glutathione (GSH) biosynthesis, the mammalian glutamate cysteine ligase (Gcl) catalytic (Gclc) and modifier (Gclm) subunits are regulated at multiple levels, whereas the function and regulatory mechanism of insect Gcl remain to be explored. In this study, we identified and characterized SfGclc and SfGclm in Spodoptera frugiperda. SfGclc and SfGclm were highly expressed in the hindgut and relatively less expressed in other tissues. The exposure of the third instar larvae to LC30 of emamectin benzoate (EMB) significantly reduced the GSH content with a concomitant upregulation of SfGclc and SfGclm. Further in vivo pretreatment with L-BSO, the Gcl inhibitor, increased the susceptibility of S. frugiperda to EMB. Consistently, overexpression of SfGclc and SfGclm increased the Sf9 cell viability under EMB treatment. Finally, both RNAi and the dual-luciferase reporter assay in Sf9 cells revealed that SfGclc is regulated by transcription factor CncC. These data provide insights into the function and regulatory mechanism of insect Gcl, and they imply that disruption of the redox homeostasis might be a practical strategy to enhance the insecticidal activity of EMB and other insecticides.

Transcriptome analysis of emamectin benzoate caused midgut damage by inducing oxidative stress, energy metabolism disorder and apoptosis in gypsy moth (Lymantria dispar)

BACKGROUND

Emamectin benzoate (EMB) is a semisynthetic bioinsecticide, which has been widely used in the control of forestry and agricultural pests. However, the mechanism of its toxic effects on the non-neural tissues has been rarely reported. Here, we explored the mechanism of the midgut damage induced by EMB in gypsy moth (Lymantria dispar) in order to better understand the toxicological mechanism of EMB.

RESULTS

Our results confirmed that EMB caused damage to the midgut of gypsy moth by inducing apoptosis. Transcriptome showed that 1469, 650 and 950 genes were significantly differentially expressed in the midgut of gypsy moth after 24, 48 and 72 h of EMB exposure, and oxidative stress, energy metabolism disorder and apoptosis may be related to the toxic effects of EMB. The indicators related to oxidative stress, energy metabolism and apoptosis were further examined. The results showed that EMB could cause oxidative stress by increasing ROS level and inhibiting antioxidant enzymes (P < 0.05), such as catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx), which in turn causes mitochondria injury. Subsequently, energy metabolism was inhibited by downregulating the activities and mRNA level of energy metabolism enzymes. Furthermore, the mitochondrial apoptosis pathway was activated, triggering apoptosis, and eventually causing midgut injury in gypsy moth.

CONCLUSION

Our results indicated that EMB caused damage to midgut by inducing oxidative stress, energy metabolism disorder and apoptosis in gypsy moth. Our findings shed new light on the toxicological mechanism of EMB on non-neural tissues from oxidative stress, energy metabolism and apoptosis perspectives. © 2022 Society of Chemical Industry.

Programmed cell death process in freshwater Microcystis aeruginosa and marine Phaeocystis globosa induced by a plant derived allelochemical

Harmful algal blooms (HAB) are a serious problem worldwide. Allelochemicals from natural plants were recently thought to be promising anti-algaecide in controlling harmful algae. However, the programmed cell death (PCD) process of algae under allelopathic pressure induced by 5,4'-dihydroxyflavone (5,4'-DHF) was poorly understood. In this study, two common and worldwide distributed microalgae, Microcystis aeruginosa and Phaeocystis globosa were selected as target algae, and the PCD processes induced by 5,4'-DHF were cross-compared between the two species. Both algae species were inhibited significantly by 5,4'-DHF with the relative sensitivity of 0.11. To uncover the PCD progress systematically, signals for PCD triggering, antioxidant enzyme activity, photosynthetic ability variation, caspase-like activities and typical indicators were investigated. In both species, typical indicators of PCD - phosphatidylserine externalization and chromatin condensation - were detected. The intracellular reactive oxygen species (ROS), nitric oxide (NO) and H₂O₂ were the potential signal molecules to stimulate PCD, and caspase-like activities were activated with an elevation of cytochrome c indicating the initiation of PCD in both species. However, P. globosa responded to 5,4'-DHF immediately after 3 h with the elevation of ROS and not in M. aeruginosa. Antioxidant enzyme activities of superoxide dismutase (SOD) and catalase (CAT) in M. aeruginosa and P. globosa also showed different patterns on day 3. Specifically, SOD activity in M. aeruginosa increased significantly while it decreased significantly in P. globosa, CAT activity in M. aeruginosa decreased significantly while it increased significantly in P. globosa (p < 0.05). Malondialdehyde (MDA) content in P. globosa increased significantly (p < 0.001) while it showed no variation in M. aeruginosa. Overall, this study is one of the earliest studies to explore the inhibition and action mechanism of plant derived flavonoids on harmful algae from the perspective of PCD, and provide new insights into the antialgal mechanism of allelochemicals.

Mulberry Ethanol Extract and Rutin Protect Alcohol-Damaged GES-1 Cells by Inhibiting the MAPK Pathway

Mulberry extract has been proven to have the effect of resisting alcohol damage, but its mechanism is still unclear. In this study, the composition of mulberry ethanol extract (MBE) was identified by LC-MS/MS and the main components of MBE were ascertained by measuring. Gastric mucosal epithelial (GES-1) cells were used to elucidate the mechanism of MBE and rutin (the central part of MBE) helped protect against alcohol damage. The results revealed that phenolics accounted for the majority of MBE, accounting for 308.6 mg/g gallic acid equivalents and 108 substances were identified, including 37 flavonoids and 50 non-flavonoids. The treatment of 400 μg/mL MBE and 320 μM rutin reduced early cell apoptosis and the content of intracellular reactive oxygen species, malondialdehyde and increased glutathione. The qPCR results indicated that the MBE inhibits the expression of genes in the mitogen-activated protein kinase (MAPK) pathway, including p38, JNK, ERK and caspase-3; rutin inhibits the expression of p38 and caspase-3. Overall, MBE was able to reduce the oxidative stress of GES-1 cells and regulated apoptosis-related genes of the MAPK pathway. This study provides information for developing anti-ethanol injury drugs or functional foods.

Intrinsic nucleus-targeted ultra-small metal-organic framework for the type I sonodynamic treatment of orthotopic pancreatic carcinoma

BACKGROUND

Sonodynamic therapy (SDT) strategies exhibit a high tissue penetration depth and can achieve therapeutic efficacy by facilitating the intertumoral release of reactive oxygen species (ROS) with a short lifespan and limited diffusion capabilities. The majority of SDT systems developed to date are of the highly O2-dependent type II variety, limiting their therapeutic utility in pancreatic cancer and other hypoxic solid tumor types.

RESULTS

Herein, a nucleus-targeted ultra-small Ti-tetrakis(4-carboxyphenyl)porphyrin (TCPP) metal-organic framework (MOF) platform was synthesized and shown to be an effective mediator of SDT. This MOF was capable of generating large quantities of ROS in an oxygen-independent manner in response to low-intensity ultrasound (US) irradiation (0.5 W cm-2), thereby facilitating both type I and type II SDT. This approach thus holds great promise for the treatment of highly hypoxic orthotopic pancreatic carcinoma solid tumors. This Ti-TCPP MOF was able to induce in vitro cellular apoptosis by directly destroying DNA and inducing S phase cell cycle arrest following US irradiation. The prolonged circulation, high intratumoral accumulation, and nucleus-targeting attributes of these MOF preparations significantly also served to significantly inhibit orthotopic pancreatic tumor growth and prolong the survival of tumor-bearing mice following Ti-TCPP + US treatment. Moreover, this Ti-TCPP MOF was almost completely cleared from mice within 7 days of treatment, and no apparent treatment-associated toxicity was observed.

CONCLUSION

The nucleus-targeted ultra-small Ti-TCPP MOF developed herein represents an effective approach to the enhanced SDT treatment of tumors in response to low-intensity US irradiation.

Sublethal concentration of emamectin benzoate inhibits the growth of gypsy moth by inducing digestive dysfunction and nutrient metabolism disorder

BACKGROUND

Gypsy moth (Lymantria dispar) is one of the most important pests in the world. Emamectin benzoate (EMB) is widely used in the control of agricultural and forestry pests. Here, we explored the sublethal effects of EMB on gypsy moths in order to better understand the toxicological mechanism of EMB.

RESULTS

The sublethal concentration of EMB exposure significantly decreased the larvae body weight. To further explore the mechanism, indicators related to digestion and nutrient metabolism were detected. The results showed that EMB exposure caused midgut damage, reduced the activities of digestive enzymes and changed the content of sugar and amino acids. Moreover, the expression of insulin/phosphoinositide-3-kinase (PI3K)/forkhead box protein O (FoxO) pathway and sugar metabolism-related genes was abnormal. The expression of insulin receptor (InR), chico, PI3K, and protein kinase B (Akt) significantly reduced, and that of phosphatase and tensin homologue (PTEN) and FoxO increased. The expression of glycogen phosphorylase (GP) was upregulation and that of glycogen synthase (GS), trehalase (TRE) and trehalose-phosphate synthase (TPS) were downregulation. All results indicated that EMB inhibits the growth of gypsy moth by inducing midgut injury, digestive dysfunction and nutrient metabolism disorder. In addition, EMB caused midgut injury may be related to apoptosis or a collateral effect of the damage in other tissues, and more extensive and deeper research is still needed to investigate the detailed mechanism.

CONCLUSION

Our finding strengthens the understanding of the sublethal effect of EMB, and provides a theoretical basis for the application of EMB in the prevention and control of gypsy moth.

Synthesis, antioxidant activity, and density functional theory study of some novel 4-[(benzo[d]thiazol-2-ylimino)methyl]phenol derivatives: a comparative approach for the explanation of their radical scavenging activities

Background and purpose:

Radicals produced by Fenton and Haber-Weiss reactions play detrimental roles in our body. Some oxidized proteins as toxic configurations are identified in amyloid-β deposits. These deposits mostly occur in conditions, such as Alzheimer’s disease. Here, we report the synthesis, evaluation of the antioxidant activity, and implementation of density functional theory (DFT) calculations of some4- [(benzo[d]thiazol-2-ylimino) methyl]phenol derivatives. The aim of this study was to provide a comparative theoretical-experimental approach to explain the antioxidant activities of the compounds.

Experimental approach:

Compounds were synthesized by the reaction between para hydroxybenzaldehyde and aminobenzothiazole derivatives. The scavenging activity of the compounds was evaluated. Various electronic and energetic descriptors such as high occupied molecular orbital and low unoccupied molecular orbital energy gaps, bonding dissociation enthalpy of OH bond, ionization potential, electron affinity, hardness, softness, and spin density of the radical and neutral species were calculated. DFT calculations with B3LYP hybrid functional and 6-311++ G** basis set in the polarizable continuum model were utilized to obtain these descriptors.

Findings/Results:

Ascorbic acid showed the best DPPH scavenging activity. However, 4d and 4c showed promising antioxidant activity. The values of EHOMO for 4c and 4d were closer to zero, thus, they showed the best scavenging activities. The computational results were in accordance with the experimental ones. The energetic descriptors indicated that the sequential proton loss-electron transfer mechanism is preferred over other mechanisms.

Conclusion and implication:

Antioxidant activity of 4-[(Benzo[d]thiazol-2-ylimino) methyl]phenol derivatives confirmed by experimental and theoretical documents proves them as novel antioxidants against amyloid-β based disease.

DJ-1 Deficiency in Hepatocytes Improves Liver Ischemia-Reperfusion Injury by Enhancing Mitophagy

BACKGROUND & AIMS

DJ-1 is universally expressed in various tissues and organs and is involved in the physiological processes in various liver diseases. However, the role of DJ-1 in liver ischemia-reperfusion (I/R) injury is largely unknown.

METHODS

In this study, we first examined the DJ-1 expression changes in the liver tissues of mice and clinical donor after hepatic I/R by both quantitative polymerase chain reaction and Western blotting assays. Then we investigated the role of DJ-1 in I/R injury by using a murine liver I/R model.

RESULTS

We demonstrated that DJ-1 down-regulation in both human and mouse liver tissues in response to I/R injury and Dj-1 deficiency in hepatocytes but not in myeloid cells could significantly ameliorate I/R induced liver injury and inflammatory responses. This hepatoprotective effect was dependent on enhanced autophagy in Dj-1 knockout mice, because inhibition of autophagy by 3-methyladenine and chloroquine could reverse the protective effect on hepatic I/R injury in Dj-1 knockout mice.

CONCLUSIONS

Dj-1 deficiency in hepatocytes significantly enhanced mitochondrial accumulation and protein stability of PARKIN, which in turn promotes the onset of mitophagy resulting in elevated clearance of damaged mitochondria during I/R injury.

Research on allergic rhinitis improvement in asthmatic children after dust mite exposure reduction: a randomized, double-blind, cross-placebo study protocol

Background

Allergic rhinitis (AR) in children is a major respiratory inflammatory disease with a high incidence that is increasing yearly. In China, 54.93% of children with asthma have AR, which often requires synchronous treatment. House dust mites (HDMs) are common allergens that often cause attacks of AR and asthma. Reducing allergen exposure is one of the most important measures to control and treat AR and asthma attacks. Hestelia Mite Bait, containing 0.1% emamectin, is a new tool for trapping and killing dust mites, reducing the number of dust mites on mattresses and thereby potentially reducing stimulation by allergens and ultimately improving asthma and rhinitis symptoms. This single-centre, randomized, double-blind, cross-placebo trial will explore the improvement in AR in asthmatic children after dust mite exposure reduction.

Methods

We will recruit 60 children (aged 3–12 years) who have been diagnosed with AR and asthma and are allergic to dust mites as confirmed by a serum allergen test. Participants will randomly receive the Hestelia Mite Bait intervention for 8 weeks and the placebo intervention for 8 weeks. There will be a 4-week washout period between the two interventions. The primary outcome is the visual analogue scale (VAS) score of AR symptoms; the secondary outcomes include the Rhinitis Control Assessment Test (RCAT) score, Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) score, changes in the dust mite level, drug usage for asthma and AR, Asthma Control Questionnaire-5 (ACQ-5) score, and frequencies of acute asthma attacks, emergency visits, and hospitalizations.

Discussion

This study aims to scientifically and objectively evaluate the effects of mite bait on rhinitis and asthma improvement after dust mite exposure reduction and provides a convenient means for future prevention and treatment of allergic diseases involving the airways in children.

Trial registration

www.chictr.org.cn ChiCTR1900024688. Registered on July 21, 2019

ROS induced by spring viraemia of carp virus activate the inflammatory response via the MAPK/AP-1 and PI3K signaling pathways

Spring viraemia of carp virus (SVCV) can cause a high mortality in common carp (Cyprinus carpio), and its main pathological processes include the inflammatory response. However, the detailed mechanism is still unclear. Reactive oxygen species (ROS) have been shown to play critical roles in the immune response, including inflammation, in different models. Our previous studies have demonstrated that SVCV infection results in the accumulation of ROS, including H₂O₂, in epithelioma papulosum cyprini (EPC) cells. In this study, we aimed to explore the relationship between H₂O₂ accumulation and inflammation during SVCV infection. After EPC cells were infected with SVCV, the expression levels of the inflammatory factors tumor necrosis factor (TNF)-α, cyclooxygenase (COX)-2, and interleukin (IL)-8 were up-regulated, while the expression of the anti-inflammatory factor interleukin (IL)-10 was down-regulated, compared with that in mock-infected EPC cells. The antioxidant N-acetyl-l-cysteine (NAC) could dampen the increased TNF-ɑ and COX-2 expression induced by SVCV and H₂O₂, suggesting a relationship between ROS accumulation and inflammation during SVCV infection. Dual luciferase reporter assays demonstrated that SVCV could not activate the NF-κB pathway. In addition, inhibition of NF-κB by pyrrolidine dithiocarbamate (PDTC) treatment had no effect on the expression of inflammatory factors. Furthermore, inhibition of the ERK, JNK, and p38MAPK signaling pathways by U0126, SP600125, and SB203580, respectively, reduced the expression of TNF-ɑ, COX-2, and IL-8, indicating that these three signaling pathways were all involved in the inflammatory response after SVCV infection. In addition, the PI3K signaling pathway was involved in the expression of the chemokine IL-8 in the SVCV-induced inflammatory response. We also showed that inhibition of the MAPK or PI3K signaling pathway facilitated the expression of SVCV-G as well as increased the SVCV viral titer. Altogether these results reveal the mechanism of the SVCV-mediated inflammatory response. Thus, targeting these signaling pathways may provide novel treatment strategies for SVCV-mediated diseases.

Toxic mechanism of eucalyptol and β-cyclocitral on Chlamydomonas reinhardtii by inducing programmed cell death

Eucalyptol and β-cyclocitral are 2 main compounds in cyanobacterial volatile organic compounds and can poison other algae. To uncover the toxic mechanism of the 2 compounds, the cell growth, photosynthetic abilities, H₂O₂ production, caspase-like activities, nuclear variation and DNA laddering were investigated in Chlamydomonas reinhardtii treated with eucalyptol and β-cyclocitral. Eucalyptol at ≥ 0.1 mM and β-cyclocitral at ≥ 0.05 mM showed toxic effects on C. reinhardtii cells, and 1.2 mM eucalyptol and 0.4 mM β-cyclocitral killed the whole of the cells during 24 h. During the death process, the photosynthetic pigment gradually degraded, and Fv/Fm gradually declined, indicating that the death is not a necrosis due to the gradual disappearance of the physiological process. In the treatments with 1.2 mM eucalyptol and 0.4 mM β-cyclocitral, H₂O₂ content burst at 10 min and 30 min, respectively. Caspase-9-like and caspase-3-like were activated, and cell nucleuses concentrated firstly and then broke with prolonging the treatment time. Meanwhile, DNA showed laddering after 1 h, and was gradually cleaved by Ca²⁺-dependent endonucleases to mainly about 100-250 bp fragments. These hallmarks indicated that eucalyptol and β-cyclocitral may poison other algal cells by inducing programmed cell death triggered by the increased H₂O₂.

Comparative cytotoxic effects of five commonly used triazole alcohol fungicides on human cells of different tissue types

The widespread application of triazole fungicides makes people attach great concern over its adverse effects in mammalian. In this paper, cytotoxic effects of triazole alcohol fungicides (TAFs) were assessed on human HeLa, A549, HCT116 and K562 cells, and the potential mechanism of TAFs cytotoxicity was studied preliminarily. Results showed that TAFs had cytotoxicity on human cells with different level and cytotoxic selectivity. TAFs cytotoxicity was resonated with a typical hormetic biphasic dose action that produced a complex pattern of stimulatory or inhibitory effects on cell viability. Among the five TAFs, diniconazole revealed a widest range of cytotoxicity to inhibit the viability of the adherent and the suspension cells, causing HeLa cells shrinkage, A549 cells shrunken, and K562 cells collapse, and showed stronger cytotoxicity than hexaconazole. Moreover, the involvement of ROS generation in the cytotoxicity of TAFs on human cells was observed, and the apoptosis of HeLa cells and the formation of apoptotic body in K562 cells induced by diniconazole were characterized. The results indicated the cytotoxicity of TAFs with different structures on human cells was depended on their own property and cell specificity, K562 cells were the most susceptible to TAFs and diniconazole was the strongest toxic.

Toxic effects of the Emamectin Benzoate exposure on cultured human bronchial epithelial (16HBE) cells

Pesticides pollution has caused serious environmental problems in recent years, and mounting evidence has shown that more and more insecticides have serious risk in human health. Emamectin Benzoate formally regarded as a highly safety insecticide based on its exclusive targets, but the cytotoxicity to human lung was ignored for a long time. In the present study, bioassay experiments were used to assess the toxicity of the Emamectin Benzoatein on human non-target cells including cell viability assay, DNA damage assay, flow cytometer assay and western blotting assay. The results indicated that Emamectin Benzoatecan cause the inhibition of the proliferation, cytochrome c release, activation of caspase-3/9 and increase Bax/Bcl-2 ratio, which means it induced the cytotoxicity on 16HBE cells associated with the mitochondrial apoptosis. Besides, the DNA damge caused by the Emamectin Benzoate suggest it has a potential genotoxic effect on human lung cells.

Chronic neurodegeneration by aflatoxin B1 depends on alterations of brain enzyme activity and immunoexpression of astrocyte in male rats

Aflatoxin B1 poses the greatest risk among the mycotoxins to target-organisms particularly human, however, no studies addressed the neurotoxicity of chronic exposure of aflatoxin. The oral dose level 1/600th of LD50 for 30, 60, and 90 days was used for three aflatoxin groups, respective to negative and vehicle control groups. Activity levels of brain antioxidants viz: superoxide dismutase, catalase, glutathione, and glutathione peroxidase significantly decreased in the three experimental durations in time-dependent trend, in contrast, lipid peroxidation showed a significant increase compared to controls. Significantly, chronic-dependent increase trend was noticed in the AF60 and AF90 group for acid phosphatase (16.1%, 35.2%), alkaline phosphatase (32.1%, 50.8%), aspartate aminotransferase (38.7%, 120.0%) and lactate dehydrogenase (30.6%, 42.1%) activities, respectively. However, a significant 23.7% decrease in the brain creatine kinase activity following 90 days of AFB1administration. Chronic administration of aflatoxin also causes alterations in activities of protein carbonyl with a maximum increase (twofold) after 90 days. Further, histopathological and immunohistochemical results confirmed time-related vasodilation, necrosis and astrocytes gliosis by high glial fibrillary acidic protein immunostaining in response to AFB1. These findings infer that long-term exposure to AFB1 results in several pathophysiological circumstances in a duration-dependent manner concerning neurodegeneration especially Alzheimer's disease.

Effect of a beta-cypermethrin and emamectin benzoate pesticide mixture on reproductive toxicity in male mice in a greenhouse environment

With the widespread use of pesticides, the resistance to pesticides of pests has gradually increased, caused mixed pesticides to become even more widely used for practical applications. To investigate the effects of mixed pesticides on reproductive health in an occupational greenhouse environment, the greenhouse environment and the characteristics of the actual application were constructed, and then the male mice were comprehensively exposed to a mixture of the beta-cypermethrin and emamectin benzoate environmental. Additionally, the effect of the beta-cypermethrin and emamectin benzoate mixture on the reproductive health of male mice was known. The results showed that with the prolongation of exposure duration, the activities of Glutathione Peroxidase (GSH-Px), Total Superoxide Dismutase (T-SOD), Lactate dehydrogenase (LDH) and Acid phosphatase (ACP) in the testes of mice gradually decreased and the activity of Malondialdehyde (MDA) gradually increased. It was also found that the apoptosis rate of murine testicular cells increased and that DNA damage occurred with prolonged exposure duration. Therefore, it can be inferred that exposure to a mixture of the pesticides beta-cypermethrin and emamectin benzoate in the greenhouse environment may have adverse effects on the reproductive health of male mice.

Genotoxicity and carcinogenicity of ivermectin and amoxicillin in vivo systems

Antiparasitic substances are chemicals used to control or kill endoparasites and ectoparasites. Based on the premise that Ivermectin (IVM) and Amoxicillin (AMX) are commonly considered in parasitic control in mammals, the present study aimed to evaluate the carcinogenic and genotoxic potential of different concentrations of IVM and AMX through the detection of epithelial tumor test in Drosophila melanogaster. Third-instar larvae descending from the cross between wts/TM3, Sb¹ females and mwh/mwh males were treated with different concentrations of IVM (2.9, 5.8, 11.6 and 23.2 x 10^-17 mM) or AMX (1.37, 2.74, 5.48 and 10.9 x 10^-16mM). The results revealed that IVM increased the frequency of epithelial tumor in D. melanogaster considering all evaluated concentrations, while AMX showed no carcinogenic effect. Furthermore, the Micronucleus (MN) test in Tradescantia pallida was used to evaluate the genotoxic effect of IVM and AMX. T. pallida individuals were exposed for 8 hours at different concentrations of IVM (5.71, 11.42, 22.84 and 45.68 x 10^-5mM) or AMX (5.13, 10.26, 20.52 and 41.05 x 10^-3mM). Findings showed an increase in the frequency of micronuclei in T. pallida treated with 11.42, 22.84 and 45.68 x 10^-5mM of IVM. We conclude that chronic exposure to IVM is directly associated with events resulting from genetic instability (genotoxicity and carcinogenicity). On the other hand, AMX was neither carcinogenic nor genotoxic for D. melanogaster and T. pallida.

Targeting the Thioredoxin System as a Strategy for Cancer Therapy

Thioredoxin reductase (TrxR) participates in the regulation of redox reactions in organisms. It works mainly via its substrate molecule, thioredoxin, to maintain the redox balance and regulate signal transduction, which controls cell proliferation, differentiation, death, and other important physiological processes. In recent years, increasing evidence has shown that the overactivation of TrxR is related to the development of tumors. The exploration of TrxR-targeted antitumor drugs has attracted wide attention and is expected to provide new therapies for cancer treatment. In this perspective, we highlight the specific relationship between TrxR and apoptotic signaling pathways. The cytoplasm and mitochondria both contain TrxR, resulting in the activation of apoptosis. TrxR activity influences reactive oxygen species (ROS) and further regulates the inflammatory signaling pathway. In addition, we discuss representative TrxR inhibitors with anticancer activity and analyze the challenges in developing TrxR inhibitors as anticancer drugs.

Oxidative stress induced by camptothecin and hydroxyl-camptothecin in IOZCAS-Spex-II cells of Spodoptera exigua Hübner

Camptothecin (CPT) and its derivatives show potential insecticidal activities against various insect species due to target at DNA-Topoisomerase I complex and induce apoptosis death of insect cells. Oxidative stress resulted from excessive production of reactive oxygen species (ROS) has been proved to be an important component of the mechanism of pesticide toxicity. The aim of the present study was to investigate whether CPTs promote the increasing of intracellular oxidative stress by enhancing accumulation of intracellular ROS in IOZCAS-Spex-II cells derived from Spodoptera exigua Hübner. Results demonstrated that there was a significant increase in the level of intracellular ROS accompanied by markedly increased DNA damage, lipid peroxidation and protein carbonylation after exposing to CPT and hydroxyl-camptothecin (HCPT) in IOZCAS-Spex-II cells. These results documented ROS generation induced by CPT and HCPT played an essential role in toxicity and mode of action of CPTs against insects. This research will throw new light on the critical roles of oxidative stress in CPTs- induced toxicity against insects, as well as on the exploration of using CPTs as a kind of insecticide with unique mode of action in the future.

The effect of α-tocopherol and dithiothreitol in ameliorating emamectin benzoate cytotoxicity in human K562 cells involving the modulation of ROS accumulation and NF-κB signaling

Emamectin benzoate (EMB) toxicity contributes a potential risk to environment and human health. To investigate the effect of α-tocopherol (VitE) and dithiothreitol (DTT) in ameliorating EMB-induced cytotoxicity in human K562 cells, in vitro cultured human K562 cells were incubated with different concentrations of EMB in supplement with VitE and DTT when the cells were in the logarithmic phase. Next, the cell growth inhibition was evaluated using the MTT assay and cellular morphology observation. Reactive oxygen species (ROS) production was monitored using DCFH-DA probe and NF-κB signaling was determined using Western blotting. The results demonstrated that treatment with EMB (time- and concentration-dependent) showed significantly greater inhibition on K562 cell viability, heavier chromatin condensation and DNA fragmentation, and stronger suppression of NF-κB/p105 and p65/RelA expression of K562 cells than the control group (p < 0.01). The supplementation of VitE or DTT could help protect K562 cells against EMB-induced cytotoxicity by improving cell viability, preventing ROS accumulation and up-regulating NF-κB signaling through their ameliorating effects against oxidative stress induced by EMB. VitE had a stronger synergistic effect in limiting EMB cytotoxicity than DTT. Our findings indicate that VitE and DTT are potent antioxidants for human K562 cells, offering a promising means of ameliorating EMB cytotoxicity.

Molecular mechanism by which Apis cerana cerana MKK6 (AccMKK6)-mediated MAPK cascades regulate the oxidative stress response

Mitogen-activated protein kinase kinases (MKKs) are important components of the MAPK signaling pathways, which play a key role in responding to stress and inflammatory stimuli. Here, a new MKK gene, AccMKK6, was identified and functionally analyzed in Apis cerana cerana. Real-time quantitative PCR (qPCR) and Western blot analysis demonstrated that the AccMKK6 expression level was up-regulated by several environmental stresses. Moreover, the knockdown of AccMKK6 by RNA interference technology altered the expression levels of some antioxidant genes. In addition, the knockdown of AccMKK6 resulted in increased malonyldialdehyde (MDA) concentration and decreased antioxidant-related enzymes activity in honeybees. To explore the MAPK signaling pathways involved in AccMKK6, we identified the transcription factor kayak in A. cerana cerana. We analyzed the interactions of AccMKK6, Accp38b, and Acckayak using the yeast two-hybrid system. AccMKK6 and Acckayak showed similar expression profiles after several stress treatments. In addition, the expression level of Acckayak was significantly increased when AccMKK6 was silenced. Therefore, we speculate that AccMKK6 may be involved in the MAPK cascades, which play a crucial role in counteracting oxidative stress caused by external stimuli.

Characterization of Vitellogenin and Vitellogenin Receptor of Conopomorpha sinensis Bradley and Their Responses to Sublethal Concentrations of Insecticide

Conopomorpha sinensis Bradley is the dominant borer pest of Litchi chinesis and Euphoria longan. Current management of C. sinensis relies upon insecticide application to adult moths. In addition to the direct mortality induced by insecticides, a sublethal dose of insecticides also affects growth, survival, and reproduction in the exposed insects. Vitellogenin (Vg) and vitellogenin receptor (VgR) are normally identified as essential reproduction-related proteins in insects. In this study, we characterized these two genes from C. sinensis, and investigated their differential responses to sublethal concentrations of insecticide. Cloned CsVg and CsVgR consist of 5391 and 5424-bp open reading frames, which encode proteins of 1796 and 1807 amino acid residues, respectively. The CsVg protein contains the typical vitellogenin, DUF1943 and VWFD domains as other reported lepidopteran Vgs. The CsVgR was characterized as a typical low density lipoprotein receptor with two highly conserved LBD and EGF precursor domains, one hydrophobic transmembrane domain, one cytoplasmic domain, and 13 putative N-glycosylation sites. We next assessed the sublethal effect of four major insecticides on egg-laying in C. sinensis. The toxicity against C. sinensis varied among the insecticides tested, with LC₅₀ values ranging from 0.23 ppm for chlorpyrifos to 20.00 ppm for β-cypermethrin, among which emamectin benzoate (EB) showed a significant negative impact on egg-laying, survival rate, ovarian development, and mating rate of C. sinensis at LC₃₀ doses. Further investigation showed that the transcriptional level of CsVg and CsVgR were impaired in different way at 24, 48, and 72 h after EB exposure, and this result was in agreement with the diminished egg-laying of C. sinensis in the sublethal concentration EB-treated group. A repressed transcription level of CsVgR was observed at 48 h after treatment, suggesting that EB elicits a delayed response in the abundance of CsVgR. These results established different roles of CsVg and CsVgR in response to the sublethal effect of insecticides. CsVg might be a better parameter than CsVgR for assessing the effect of sublethal insecticides on reproduction in C. sinensis.

Protective effect of proanthocyanidin on mice Sertoli cell apoptosis induced by zearalenone via the Nrf2/ARE signalling pathway

This study evaluated the protective effect of proanthocyanidin (PC) on the cytotoxicity of the Sertoli cell TM4 of mice, as induced by zearalenone (ZEA). Flow cytometry was used to detect the apoptosis rate of cells in each group. The activities of antioxidant enzymes and the content of antioxidant substances were detected by using a proprietary kit; the RT-PCR method was used to detect the expression level of mRNA, the related genes of Nrf2/ARE signal pathway, the nuclear factor E2 related factor 2 (Nrf2), heme oxygenase 1 (HO-1), glutathione peroxidase (GSH-Px), quinone oxidoreductase 1 (NQO1), γ-glutamylcysteine synthetase (γ-GCS) and the expression level of mRNA, the apoptosis-related genes, Bcl-2 and Bax; the Western-blot method was used to detect the protein expression levels of Nrf2, GSH-Px, HO-1, γ-GCS and NQO1 in each group. Our results showed that PC could reduce the apoptosis rate of the TM4 cells exposed to ZEA (p < 0.01); PC could enhance the decrease in the activities of T-SOD and GSH-Px induced by ZEA (p < 0.05), reduce the increase in the content of MDA, as caused by ZEA; PC could significantly up-regulate the down-regulation levels of the mRNA and protein of Nrf2, GSH-Px, HO-1, γ-GCS and NQO1 induced by ZEA. PC could enhance the decrease in the mRNA expression level of Bcl-2 and down-regulate the mRNA expression of Bax induced by ZEA (p < 0.05). These results demonstrated that PC conferred protective effects against oxidative damage and apoptosis of TM4 cells induced by ZEA. The protection mechanism of PC on TM4 cells might act through the activation of the Nrf2/ARE signalling pathway.