Evaluation of GSTP1, GSTA4 and AChE Gene Methylation in Bovine Lymphocytes Cultured In Vitro with Miconazole Alone and in Combination with Mospilan 20SP.

5-methylcytosine (5mC) is one of the most important epigenetic modifications. Its increased occurrence in regulatory sequences of genes, such as promoters and enhancers, is associated with the inhibition of their expression. Methylation patterns are not stable but are sensitive to factors such as the environment, diet, and age. In the present study, we investigated the effects of fungicide miconazole, both alone and in combination with the insecticide Mospilan 20SP, on the methylation status of bovine GSTP1, GSTA4, and AChE genes in bovine lymphocytes cultured in vitro. The methylation-specific PCR technique was used for the objectives of this study. We found that miconazole alone at concentrations of 1.25, 2.5, 5, 10, 25, and 50 µg/mL after 24 h exposure probably did not induce changes in methylation for all three genes analysed. The same results were found for the combination of pesticides at 24 h exposure and the following concentrations for each of them: 0.625, 1.25, 2.5, 5, and 12.5 µg/mL. Thus, we can conclude that the fungicide miconazole alone, as well as in combination with the insecticide Mospilan 20SP, was unlikely to cause changes to the methylation of bovine GSTP1, GSTA4, and AChE genes.

Structural and Functional Characterization of One Unclassified Glutathione S-Transferase in Xenobiotic Adaptation of Leptinotarsa decemlineata.

Arthropod Glutathione S-transferases (GSTs) constitute a large family of multifunctional enzymes that are mainly associated with xenobiotic or stress adaptation. GST-mediated xenobiotic adaptation takes place through direct metabolism or sequestration of xenobiotics, and/or indirectly by providing protection against oxidative stress induced by xenobiotic exposure. To date, the roles of GSTs in xenobiotic adaptation in the Colorado potato beetle (CPB), a notorious agricultural pest of plants within Solanaceae, have not been well studied. Here, we functionally expressed and characterized an unclassified-class GST, LdGSTu1. The three-dimensional structure of the LdGSTu1 was solved with a resolution up to 1.8 Å by X-ray crystallography. The signature motif VSDGPPSL was identified in the "G-site", and it contains the catalytically active residue Ser14. Recombinant LdGSTu1 was used to determine enzyme activity and kinetic parameters using 1-chloro-2, 4-dinitrobenzene (CDNB), GSH, p-nitrophenyl acetate (PNA) as substrates. The enzyme kinetic parameters and enzyme-substrate interaction studies demonstrated that LdGSTu1 could catalyze the conjugation of GSH to both CDNB and PNA, with a higher turnover number for CDNB than PNA. The LdGSTu1 enzyme inhibition assays demonstrated that the enzymatic conjugation of GSH to CDNB was inhibited by multiple pesticides, suggesting a potential function of LdGSTu1 in xenobiotic adaptation.

The role of emodin on cisplatin resistance reversal of lung adenocarcinoma A549/DDP cell.

Exploring drugs that reverse drug resistance and increase the sensitivity of chemotherapy drugs could significantly improve treatment effect of cancer. Our study explored the reversal effect and possible molecular mechanisms of emodin on cisplatin resistance in A549/DDP cells. The IC50 and resistance index of cells were determined by Cell Counting Kit-8 assay. The ability of cell proliferation was evaluated by wound healing assay. Transwell assay was used to detect cell invasion and migration. Apoptosis induction rate was determined by flow cytometry assay and 4',6- diamidino- 2-phenylindole staining. Intracellular concentration was determined by HPLC. Western blot analysis was applied to determine expressions of nuclear factor kappa beta (NF-κB) and its downstream proteins. In this study, we found that the growth inhibitory effect of cisplatin was significantly enhanced by emodin in A549/DDP cells. The combined use of emodin with DDP can effectively promote lung cancer cells apoptosis and inhibit cell migration and invasion. Further investigation indicated that reinforcement effect of emodin and DDP may be associated with inhibition of NF-κB pathway and drug efflux-related proteins such as P-glycoprotein (P-gp), multidrug resistance-associated protein (MRP) and Glutathione S-transferase (GST). The key role of NF-κB was further confirmed by the application of NF-κB inhibitor Ammonium pyrrolidinedithiocarbamate. The intervention of both can significantly increase A549/DDP cell apoptosis and inhibit DDP-induced upregulation of P-gp, MRP and GST. Emodin reverses the cisplatin resistance of tumor cells by down-regulating expression of P-gp, MRP and GST, increasing the intracellular accumulation in A549/DDP cells, and the effect may be associated with the NF-κB pathways.

Resistance to commonly used insecticides and underlying mechanisms of resistance in Aedes aegypti (L.) from Sri Lanka.

BACKGROUND: Drastic increases of dengue fever (DF) over the past few years have prompted studies on the development of resistance to insecticides in the mosquito vector, Aedes aegypti (Linnaeus). In Sri Lanka control of the vector population is essentially achieved using larvicides (temephos) and adulticides (principally pyrethroids). The present study investigates resistance to commonly used insecticides and underlying mechanisms of Ae. aegypti in selected sites in Sri Lanka. METHODS: In this study, susceptibility to three commonly used adulticides (malathion, permethrin and deltamethrin) and the larvicide temephos were tested for Ae. aegypti sampled from five localities in Sri Lanka using WHO dose diagnostics tests. In addition, we performed dose-response tests for permethrin to determine lethal concentrations (LCs) with CDC bottle bioassays. An assessment of the activity of metabolic detoxifying enzymes (multifunction oxidases (MFOs), glutathione S-transferases (GSTs) and esterases) and determination of frequency of the kdr mutations (F1534C, V1016G and S989P) were also carried out to ascertain the associated resistance mechanisms. Kdr genotype frequencies were compared with samples collected from the same sites in 2015 to determine the change of allele frequencies over the years. RESULTS: The present study revealed resistance in all Ae. aegypti populations studied, with low mortality percentages for both permethrin (10-89%) and deltamethrin (40-92%). Dose response tests revealed highest resistance ratios (RR) for permethrin and temephos from Colombo district whereas Puttalum district exhibited the lowest. High frequencies of the 1534C allele (0.052-0.802) were found in the study sites in 2017. Comparison with samples collected in 2015 revealed a substantial increase in this allele. The activity of MFOs and p-nitro phenyl-acetate esterase was significantly greater in most Sri Lankan populations in comparison to that of the New Orleans (NO) susceptible strain. In contrast, the activity of α-esterase and ß-esterase was similar or lower than that in the NO strain. CONCLUSIONS: Aedes aegypti from Sri Lanka is resistant to pyrethroid insecticides showing rapid selection for kdr mutations and varying metabolic mechanisms. Continued monitoring of vector populations is crucial to mitigate the development of resistance to commonly used insecticides and in turn, controlling the vector population.

lincRNA_Tc13743.2-miR-133-5p-TcGSTm02 regulation pathway mediates cyflumetofen resistance in Tetranychus cinnabarinus.

Differential expression of metabolic detoxification enzymes is an important mechanism involved in pesticide/acaricide resistance of mite pests. The competing endogenous RNA hypothesis offers a new opportunity to investigate post-transcriptional regulation of those genes. In this study, 4454 long non-coding RNAs were identified in the carmine spider mite Tetranychus cinnabarinus by transcriptome sequencing. Software-based predictions indicated that a long intergenic non-coding RNA, (lincRNA)_Tc13743.2 and a detoxification enzyme gene, TcGSTm02, both contained a microRNA (miR-133-5p) response element. Over-expression of lincRNA_Tc13743.2 and TcGSTm02 were detected in a cyflumetofen-resistant T. cinnabarinus strain (CyR), whereas down-regulation of miR-133-5p was observed in this strain. Conversely, up-regulation of miR-133-5p could inhibit TcGSTm02 expression levels, and both lincRNA_Tc13743.2 and TcGSTm02 were significantly enriched in miR-133-5p biotin-avidin pull-down assays. RNA-binding protein immunoprecipitation assay showed that lincRNA_Tc13743.2 and TcGSTm02 bound to a silencing complex containing miR-133-5p. Moreover, a luciferase reporter assay based on a human cell line revealed that over-expression of lincRNA_Tc13743.2 could significantly reduce the inhibition exerted by miR-133-5p through the TcGSTm02 3'UTR. In addition, co-localization of lincRNA_Tc13743.2 and miR-133-5p was detected using fluorescence in situ hybridization, suggesting that lincRNA_Tc13743.2 interacts directly with miR-133-5p in spider mites. More importantly, silencing the expression of lincRNA_Tc13743.2 significantly reduced the expression levels of TcGSTm02 and increased the sensitivity of spider mites to cyflumetofen. Our data show that lincRNA_Tc13743.2 up-regulates TcGSTm02 expression by competing for miR-133-5p binding, demonstrating that a lincRNA_Tc13743.2-miR-133-5p-TcGSTm02 pathway mediates cyflumetofen resistance in mites.

Chronic exposure of adult male Wistar rats to bisphenol A causes testicular oxidative stress: Role of gallic acid.

OBJECTIVES: Bisphenol A (BPA) has been reported that among other male reproductive dys-functions, it can cause marked estrogenic effects including alteration in serum hormones as well as testicular lesions in exposed animals. This work sought to study the role of gallic acid (GA), a known antioxidant, on the BPA-induced testicular oxidative stress in adult male Wistar rats using serum hormone analysis, histopathology, and biochemical assays. METHODS: Adult male rats were divided into four groups (n=10) including control (0.2 ml of corn oil), GA (20 mg/kg/day), BPA (10 mg/kg/day), BPA+GA (BPA, 10 mg/kg/day + GA, 20 mg/kg/day). All medications were given by oral gavage for 45 consecutive days. The body and testicular weights were measured. Blood and organ samples were collected for the serum hormonal assay: testosterone (T), luteinizing hormone (LH), follicle stimulating hormone (FSH) and prolactin (PRL), and tissue biochemistry analysis: superoxide dismutase (SOD), reduced glutathione (GSH), glutathione-S-transferase (GST), malondialdehyde (MDA), hydrogen peroxide (H2O2), respectively. RESULTS: The BPA-treated rats showed significant reduction in the gonadosomatic index. BPA also caused significant decrease in the levels of the serum testosterone and prolactin. Furthermore, BPA induced testicular oxidative stress by decreasing the activities of antioxidant enzymes and increasing reactive oxygen species. However, co-treatment with GA protected against these alterations. CONCLUSION: Findings from the present study confirmed the previously reported data and show that the ability of GA, as a potent antioxidant, may protect against BPA-induced alterations in the male reproductive function. Hence, GA protects against testicular oxidative stress in adult male Wistar rats following chronic exposure to BPA.

Thallium Toxicity in Caenorhabditis elegans: Involvement of the SKN-1 Pathway and Protection by S-Allylcysteine.

Monovalent thallium (Tl+) is a cation that can exert complex neurotoxic patterns in the brain by mechanisms that have yet to be completely characterized. To learn more about Tl+ toxicity, it is necessary to investigate its major effects in vivo and its ability to trigger specific signaling pathways (such as the antioxidant SKN-1 pathway) in different biological models. Caenorhabditis elegans (C. elegans) is a nematode constituting a simple in vivo biological model with a well-characterized nervous system, and high genetic homology to mammalian systems. In this study, both wild-type (N2) and skn-1 knockout (KO) mutant C. elegans strains subjected to acute and chronic exposures to Tl+ [2.5-35 µM] were evaluated for physiological stress (survival, longevity, and worm size), motor alterations (body bends), and biochemical changes (glutathione S-transferase regulation in a gst-4 fluorescence strain). While survival was affected by Tl+ in N2 and skn-1 KO (worms lacking the orthologue of mammalian Nrf2) strains in a similar manner, the longevity was more prominently decreased in the skn-1 KO strain compared with the wild-type strain. Moreover, chronic exposure led to a greater compromise in the longevity in both strains compared with acute exposure. Tl+ also induced motor alterations in both skn-1 KO and wild-type strains, as well as changes in worm size in wild-type worms. In addition, preconditioning nematodes with the well-known antioxidant S-allylcysteine (SAC) reversed the Tl+-induced decrease in survival in the N2 strain. GST fluorescent expression was also decreased by the metal in the nematode, and recovered by SAC. Our results describe and validate, for the first time, features of the toxic pattern induced by Tl+ in an in vivo biological model established with C. elegans, supporting an altered redox component in Tl+ toxicity, as previously described in mammal models. We demonstrate that the presence of the orthologous SKN-1 pathway is required for worms in evoking an efficient antioxidant defense. Therefore, the nematode represents an optimal model to reproduce mammalian Tl+ toxicity, where toxic mechanisms and novel therapeutic approaches of clinical value may be successfully pursued.

Impact of deltamethrin selection on kdr mutations and insecticide detoxifying enzymes in Aedes aegypti from Mexico.

BACKGROUND: Insecticide resistance is a serious problem for vector control programmes worldwide. Resistance is commonly attributed to mutations at the insecticide's target site or increased activity of detoxification enzymes. METHODS: We determined the knockdown concentration (KC50) and lethal concentration (LC50) of deltamethrin in six natural populations of adult Aedes aegypti from southeastern Mexico. These populations were then selected over five generations using the LC50 from the preceding generation that underwent selection, and the heritability of deltamethrin resistance was quantified. For each generation, we also determined the frequency of the kdr alleles L410, I1016 and C1534, and the levels of activity of three enzyme families (α- and ß-esterases, mixed-function oxidases and glutathione S-transferases (GST)) associated with insecticide detoxification. RESULTS: There was an increase in KC50 and LC50 values in the subsequent generations of selection with deltamethrin (FS5vs FS0). According to the resistance ratios (RRs), we detected increases in LC50 ranging from 1.5 to 5.6 times the values of the parental generation and in KC50 ranging from 1.3-3.8 times the values of the parental generation. Triple homozygous mutant individuals (tri-locus, LL/II/CC) were present in the parental generations and increased in frequency after selection. The frequency of L410 increased from 1.18-fold to 2.63-fold after selection with deltamethrin (FS5vs FS0) in the populations analyzed; for I1016 an increase between 1.19-fold to 2.79-fold was observed, and C1534 was fixed in all populations after deltamethrin selection. Enzymatic activity varied significantly over the generations of selection. However, only α- esterase activity remained elevated in multiple populations after five generations of deltamethrin selection. We observed an increase in the mean activity levels of GSTs in two of the six populations analyzed. CONCLUSIONS: The high levels of resistance and their association with high frequencies of kdr mutations (V410L, V1016I and F1534C) obtained through artificial selection, suggest an important role of these mutations in conferring resistance to deltamethrin. We highlight the need to implement strategies that involve the monitoring of kdr frequencies in insecticide resistance monitoring and management programmes.

High concentration of MSG alters antioxidant defence system in lobster cockroach Nauphoeta cinerea (Blattodea: Blaberidae).

OBJECTIVE: Monosodium glutamate (MSG) is a food additive that has been shown to be toxic to rodents at high concentrations. The available studies in Drosophila melanogaster suggest that MSG toxicity depends on concentration and gender, thus the safety of MSG as a food enhancer still requires further investigation. We have documented impaired locomotor activity and altered oxidative stress markers in cockroaches co-exposed to methylmercury and monosodium glutamate (MSG). We herein examined the susceptibility of Nauphoeta cinerea to high and low concentrations (4% and 1%) of MSG, while monitoring the activities of acetylcholinesterase (AChE), as well as markers of oxidative stress and antioxidant activity over 30 days. RESULTS: There was no significant alteration in the parameters assessed at 1% MSG while 4% MSG caused an increase in the activity of reactive oxygen and nitrogen species, with a corresponding reduction in the activities of acetylcholinesterase, glutathione-S-transferase and catalase, suggesting the capacity of MSG to alter redox homeostasis in Nauphoeta cinerea.

Study on Effects and Mechanism of Lead and High-Fat Diet on Cognitive Function and Central Nervous System in Mice.

OBJECTIVE: We sought to investigate the effects and mechanism of lead and a high-fat diet on cognitive function and the central nervous system in mice. METHODS: Eighty-four healthy male mice were randomly divided into a control group (n = 21) (fed with common diet and free drinking), a lead exposure group (n = 21) (fed with common diet and 300 mg/L lead acetate solution), a high-fat group (n = 21) (fed with high-fat diet and free drinking), and a lead + high-fat group (n = 21) (fed with high-fat diet and 300 mg/L lead acetate solution). In 10 weeks after lead exposure, the mice of all groups were tested for the cognition, learning and memory abilities, body weight, serum triglyceride (TG), low-density lipoprotein, and high-density lipoprotein, as well as for the contents of lead, interleukin 6 (IL-6), interleukin 17 (IL-17), interferon γ, advanced glycation end products (AGEs), glutathione S-transferase (GSH-ST), and hydrogen peroxide in the brain tissues. RESULTS: Compared with the control group and the lead-exposed group, the body weights of mice in the high-fat group and the lead + high-fat group increased significantly from the sixth week of the experiment, of which the difference was statistically significant (P < 0.05). Compared with the control group and the high-fat group, the lead content in brain tissue of the lead exposure group and the lead + high-fat group increased significantly, of which the difference was statistically significant (P < 0.05). Compared with the control group, the escape latent period, triglyceride, low-density lipoprotein, IL-6, IL-17, interferon γ, and AGEs of the remaining 3 groups increased significantly, but the recognition index, passing platform times, high-density lipoprotein, and GSH-ST significantly decreased (P < 0.05); the second and third escape latent periods, IL-6, IL-17, and AGEs of lead + high-fat group, were obviously higher than the remaining 3 groups, but the passing platform times were obviously lower than the remaining 3 groups, of which the difference was statistically significant. The content of hydrogen peroxide in brain tissues had no difference among groups (P > 0.05). CONCLUSIONS: The lead and high-fat diet resulted in lipid metabolism disorders and impaired the cognitive function and central nervous system by promoting the secretion of inflammatory factors in glial cells, inducing the inflammatory reaction of brain tissue, inhibiting GSH-ST expression, and increasing AGEs content.

Inhibition of connexin 43 attenuates oxidative stress and apoptosis in human umbilical vein endothelial cells.

BACKGROUND: Previous studies demonstrated an important role for connexin 43 (Cx43) in the regulation of apoptosis by influencing mitochondrial functions. This study aimed to investigate the relationship between Cx43 and lipopolysaccharide (LPS)-induced oxidative stress and apoptosis in human umbilical vein endothelial cells (HUVECs). METHODS: Western blot was performed to determine mitochondrial Cx43 (MtCx43) protein level and phosphorylation (p-MtCx43). Gap19, a selective Cx43 inhibitor, was used to examine the effects of Cx43 on LPS-induced oxidative stress and apoptosis in HUVECs. Expression of regulatory genes associated with oxidative stress was examined by quantitative polymerase chain reaction (qPCR) and Western blot. Apoptosis was assessed by flow cytometry. RESULTS: LPS stimulation resulted in increased levels of MtCx43 and p-MtCx43. Interestingly, Gap19 antagonized the upregulation of glutathione S-transferase Zeta 1 (GSTZ1) and cytochrome b alpha beta (CYBB), and the downregulation of antioxidant 1 (ATOX1), glutathione synthetase (GSS) and heme oxygenase 1 (HMOX1) induced by LPS or Cx43 overexpression. Moreover, the increased production of reactive oxygen species (ROS) and apoptosis elicited by LPS or Cx43 overexpression were reduced following treatment with Gap19. CONCLUSIONS: Selective inhibition of Cx43 hemichannels protects HUVECs from LPS-induced apoptosis and this may be via a reduction in oxidative stress production.

Role of 7-chloro-4-(phenylselanyl) quinoline as an anti-aging drug fighting oxidative damage in different tissues of aged rats.

This study investigated whether subacute treatment with 7-chloro-4-(phenylselanyl) quinoline (4-PSQ) presented antioxidant action in oxidative stress associated with aging in different rat tissues. We also investigated whether plasma selenium levels were altered by aging, as well as the contribution of 4-PSQ administration to these levels. Aged Wistar male rats (23month old) were intragastrically treated with 4-PSQ (5mg/kg) for seven days. On the 14th day of the experimental protocol, plasma was collected to determine selenium levels and biochemical markers of renal and hepatic damage. Furthermore, liver, kidney, spleen and cerebral cortex were removed to determine thiobarbituric acid reactive species (TBARS), non-protein thiols (NPSH), glutathione S-transferase (GST), catalase (CAT) and δ-aminolevulinate dehydratase (ALA-D). Our results showed that one or more parameters changed markedly in the liver, kidney, spleen and cerebral cortex of aged rats. Moreover, biochemical markers of renal and hepatic damage and selenium levels are changed in the plasma of aged rats. Treatment with 4-PSQ repaired redox homeostasis in tissues of aged rats, as well as plasma biochemical markers of renal and hepatic damage and selenium levels. In conclusion, 4-PSQ presented an antioxidant effect in tissues of aged rats, restoring selenium levels, and contributing to the restoration of the damage caused by aging. Thus, 4-PSQ could be a potential candidate for the management of age-related oxidative damage, acting as an anti-aging drug.

Effects of Substrate-Binding Site Residues on the Biochemical Properties of a Tau Class Glutathione S-Transferase from Oryza sativa.

Glutathione S-transferases (GSTs)-an especially plant-specific tau class of GSTs-are key enzymes involved in biotic and abiotic stress responses. To improve the stress resistance of crops via the genetic modification of GSTs, we predicted the amino acids present in the GSH binding site (G-site) and hydrophobic substrate-binding site (H-site) of OsGSTU17, a tau class GST in rice. We then examined the enzyme activity, substrate specificity, enzyme kinetics and thermodynamic stability of the mutant enzymes. Our results showed that the hydrogen bonds between Lys42, Val56, Glu68, and Ser69 of the G-site and glutathione were essential for enzyme activity and thermal stability. The hydrophobic side chains of amino acids of the H-site contributed to enzyme activity toward 4-nitrobenzyl chloride but had an inhibitory effect on enzyme activity toward 1-chloro-2,4-dinitrobenzene and cumene hydroperoxide. Different amino acids of the H-site had different effects on enzyme activity toward a different substrate, 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole. Moreover, Leu112 and Phe162 were found to inhibit the catalytic efficiency of OsGSTU17 to 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole, while Pro16, Leu112, and Trp165 contributed to structural stability. The results of this research enhance the understanding of the relationship between the structure and function of tau class GSTs to improve the abiotic stress resistance of crops.

Functional Analysis of an Epsilon-Class Glutathione S-Transferase From Nilaparvata lugens (Hemiptera: Delphacidae).

Glutathione conjugation is a crucial step in xenobiotic detoxification. In the current study, we have functionally characterized an epsilon-class glutathione S-transferase (GST) from a brown planthopper Nilaparvata lugens (nlGSTE). The amino acid sequence of nlGSTE revealed approximately 36-44% identity with epsilon-class GSTs of other species. The recombinant nlGSTE was prepared in soluble form by bacterial expression and was purified to homogeneity. Mutation experiments revealed that the putative substrate-binding sites, including Phe107, Arg112, Phe118, and Phe119, were important for glutathione transferase activity. Furthermore, inhibition study displayed that nlGSTE activity was affected by insecticides, proposing that, in brown planthopper, nlGSTE could recognize insecticides as substrates.

Molluscicidal activity and physiological toxicity of quaternary benzo[c]phenanthridine alkaloids (QBAs) from Macleaya cordata fruits on Oncomelania hupensis.

Schistosomiasis is a serious worldwide parasitic disease. One of the best ways to control schistosomiasis is to control the population of Oncomelania hupensis snails. We sought to identify a high-efficiency biogenic molluscicide against Oncomelania with low toxicity, to avoid chemical molluscicide contamination and toxicity in aquatic organisms. We extracted quaternary benzo[c]phenanthridine alkaloids (QBAs) from Macleaya cordata fruits. Molluscicidal activity of the QBAs against Oncomelania was determined using bioassay. Our results showed that the extracted QBAs had a strong molluscicidal effect. In treatment of O. hupensis with QBAs for 48 h and 72 h, the lethal concentration (LC50) was 2.89 mg/L and 1.29 mg/L, respectively. The molluscicidal activity of QBAs was close to that of niclosamide (ethanolamine salt), indicating that QBAs have potential development value as novel biogenic molluscicides. We also analyzed physiological toxicity mechanisms by examining the activity of several important detoxification enzymes. We measured the effect of the extracted QBAs on the activities of glutathione S-transferase (GST), carboxylesterase (CarE), acid phosphatase (ACP), and alkaline phosphatase (AKP) in the liver of O. hupensis. We found that the effects of QBAs on detoxification metabolism in O. hupensis were time and concentration dependent. The activities of GST, CarE, AKP, and ACP in the liver of snails increased significantly in the early stage of treatment (24 h), but decreased sharply in later stages (120 h), compared with these activities in controls. GST, CarE, AKP, and ACP activity in the liver of snails treated with LC50 QBAs for 120 h decreased by 62.3%, 78.1%, 59.2%, and 68.6%, respectively. Our results indicate that these enzymes were seriously inhibited by the extracted QBAs and the detoxification and metabolic functions of the liver gradually weakened, leading to poisoning, which could be the main cause of death in O. hupensis snails.

Synthesis and Target Identification of a Novel Electrophilic Warhead, 2-Chloromethylquinoline.

Despite its power in identifying highly potent ligands for select protein targets, conventional medicinal chemistry is limited by its low throughput and lack of proteomic selectivity information. We seek to develop a chemoproteomic approach for discovering covalent ligands for protein targets in an unbiased, high-throughput manner. Tripartite probe compounds composed of a heterocyclic core, an electrophilic "warhead", and an alkyne tag have been designed and synthesized for covalently labeling and identifying targets in cells. We have developed a novel condensation reaction to prepare 2-chloromethylquinoline (2-CMQ), an electrophilic heterocycle. These chloromethylquinolines potently and covalently bind to a number of cellular protein targets, including prostaglandin E synthase 2 (PTGES2), a critical regulator of cell proliferation, apoptosis, angiogenesis, inflammation, and immune surveillance. The 2-CMQs that we have developed here are novel PTGES2 binders that have the potential to serve as therapies for the treatment of human diseases such as inflammation.

The GLP-1 analog liraglutide attenuates acute liver injury in mice.

INTRODUCTION AND OBJECTIVES: Acute liver injury is a current health problem with few effective treatments. The present study investigated the hepatoprotective and curative potential of the glucagon-like peptide-1 analog liraglutide against carbon tetrachloride (CCl4)-induced hepatotoxicity. MATERIALS AND METHODS: Male Swiss mice were subjected to two protocols. The first protocol (Pretreatment) consisted of intraperitoneal (i.p.) treatment with liraglutide (0.057 and 0.118mgkg-1) or vehicle (distilled water) once daily for 7 days. On days 6 and 7, the animals were challenged with 2% CCl4 (5mgkg-1, i.p.). The second protocol (Late treatment) began with an injection of 5% CCl4 (5mgkg-1, i.p.) and subsequent treatment with liraglutide (0.057mgkg-1) or vehicle (distilled water) for 1 day. In both protocols, 24h after the last administration, blood and bile were collected from anesthetized animals, followed by euthanasia and liver collection. Plasma and bile underwent biochemical analyses, and histological, oxidative stress, and metabolic parameters were evaluated in the liver. RESULTS: Both liraglutide treatment protocols attenuated hepatotoxicity that was induced by CCl4, decreasing plasma levels of hepatic enzymes, stimulating the hepatic antioxidant system, and decreasing centrilobular necrosis, hepatic glycogen, and lipid accumulation. CCl4 tended to reduce bile lipid excretion, but liraglutide did not influence this parameter. CONCLUSIONS: The present results demonstrated the hepatoprotective and therapeutic effects of liraglutide, which may be attributable to a decrease in liver oxidative stress and the preservation of metabolism. Liraglutide may have potential as a complementary therapy for acute liver injury.

GSTO1 acts as a mediator in sodium fluoride-induced alterations of learning and memory related factors expressions in the hippocampus cell line.

The mechanism of GSTO1, as a high-risk factor for neurological damage, in sodium fluoride (NaF)-induced learning and memory impairment remained still unclear. Hence, in this study, we used the siRNA-GSTO1 HT22 model to explore the effect of NaF and siRNA-GSTO1 on the viability, and proliferation rate of HT22 cells, as well as the mRNA and protein expression levels of cyclic adenosine monophosphate (cAMP) response element binding protein (CREB), neural cell adhesion molecule (NCAM), stem cell factor (SCF) and brain-derived neurotrophic factor (BDNF). The results of MTT showed that 10-3, 10-4, and 10-5 moL/L sodium fluoride (NaF) exposure could significantly promote the proliferation of HT22 cells at 24 h, 36 h, and 48 h, respectively. In addition, our results showed that exposure to 10-3, 10-4, and 10-5 moL/l NaF increased GSTO1 mRNA and protein expression, but decreased CREB and BDNF expression levels in a dose and time-dependent manner. The mRNA and protein expressions of GSTO1, CREB and BDNF were significantly decreased in the siRNA-GSTO1 and NaF + siRNA-GSTO1 group (P < 0.05). We have shown that various NaF doses affected the learning and memory ability by down-regulation the expressions of CREB, BDNF, NCAM and SCF. In summary, we concluded that GSTO1 plays a mediator role in NaF-induced neurological damage.

Dose-Related Modulatory Effects of Polymeric Black Tea Polyphenols (PBPs) on Initiation and Promotion Events in B(a)P and NNK-Induced Lung Carcinogenesis.

Our understanding of dose-related effects of polymeric black tea polyphenols (PBPs), the most abundant polyphenols in black tea, is limited. In the present study, the effect of various doses of black tea (0.75, 1.5, and 3%)-derived PBP-rich extract on biochemical parameters and lung carcinogenicity in A/J mice was investigated. Pretreatment with PBPs showed the dose-related decrease in B(a)P-induced expression and activity of CYP1A1 in the liver while CYP1A2 expression and activity in the lung. Dose-dependent significant increase in PBP-mediated over-expression and activity of GSTs (alpha in the liver while pi in the lung) were observed in polyphenol-treated groups. Significant dose-related decrease in number and intensity of BPDE-DNA adducts were observed in liver and lung. Black tea (1.5%, 3%)-derived PBPs showed dose-mediated decrease in lung tumor incidence and multiplicity which was further correlated with different molecular markers like cell proliferation and apoptosis in B(a)P and NNK model. In conclusion, dose-dependent chemopreventive effects of PBPs, both anti-initiating (induction of phase II and inhibition of carcinogen-induced phase-I enzymes leading to decrease in BPDE-DNA adducts) and anti-promoting (decreased cell proliferation and increased apoptosis lowering incidence and/or multiplicity of lung lesions), were observed in A/J mice without significant toxicity.

Exposure to dilute concentrations of bupropion affects zebrafish early life stages.

Psychiatric pharmaceuticals are one of the most prescribed active substances globally. Bupropion (BPP) is an antidepressant that acts via inhibition of norepinephrine and dopamine reuptake. It has been found in various water matrices, and thus its effects on aquatic organisms must be studied. The present study aimed to evaluate the acute toxic effects of BPP on zebrafish (Danio rerio) early life stages. For developmental analysis, organisms were exposed for 168 h to concentrations ranging from 0 to 82000 µg/L. Two other experiments were performed by exposing embryos to a wide range of concentrations (from 0 to 50000 µg/L) in order to evaluate BPP effects on embryonic behavior, using the Zebrabox and testing at the biochemical level (acetylcholinesterase, glutathione-S-transferase, lactate dehydrogenase and catalase). Developmental analysis indicated that BPP had low acute toxicity with a calculated 168 h-LC50 of 50346 µg/L. Concentrations equal to or above 44800 µg/L elicited several effects such as hatching delay, edemas and tail deformities. However, concentrations from 7300 µg/L upwards elicited equilibrium alteration. Behavioral analysis showed that BPP affected zebrafish locomotor behavior by decreasing activity at 0.6 µg/L, increasing activity at 8.8 and 158 µg/L, and decreasing activity at 50000 µg/L. Biochemical analysis showed an increase of AChE activity at 158 and 2812 µg/L, an increase in GST at the highest concentrations, CAT alteration and increase of LDH at 0.6, 2812 and 50000 µg/L. We can conclude that BPP affects zebrafish early life stages at environmental concentrations.