Decreased Glutathione S-transferase Activity Research Articles

Biochemical and molecular characterization of neonicotinoids resistance in the tarnished plant bug, Lygus lineolaris

In the southern United States, neonicotinoids are commonly applied as foliar insecticides to control sucking insect pests, such as the tarnished plant bug (TPB, Lygus lineolaris). In this study, spraying bioassays were conducted to determine the toxicity of five neonicotinoids and sulfoxaflor to susceptible and late fall field-collected TPB adults from Mississippi Delta region. Compared to a susceptible population, the field-collected TPBs exhibited the highest resistance to imidacloprid (up to 19.5-fold), a moderate resistance to acetamiprid (9.43-fold), clothianidin (13.68-fold), thiamethoxam (7.88-fold) and the least resistance to thiacloprid (4.61-fold) and sulfoxaflor (1.82-fold), respectively. A synergist study demonstrated that piperonyl butoxide (PBO) significantly increased the toxicity of imidacloprid and thiamethoxam by 22.2- and 15.3-fold, respectively, while triphenyl phosphate (TPP) and diethyl maleate (DEM) only showed 2–3-fold synergism to both neonicotinoids. In the field-collected TPBs, activities of the three detoxification enzymes esterase, glutathione S-transferase (GST) and CYP450 monooxygenase (P450) were significantly increased by 3.43-, 1.48- and 2.70-fold, respectively, when compared to the susceptible population. Additionally, after 48 h exposure to imidacloprid or thiamethoxam, resistant TPB adults exhibited elevated esterase activities, decreased GST activities, and no significant changes in P450 activities. Further examinations revealed that the expression of certain esterase and P450 detoxification genes were significantly elevated in resistant TPBs. Overall, these results suggest that elevated esterase and P450s expression and enzyme activity are key mechanisms for metabolic resistance in TPBs to neonicotinoids. Our findings also provide valuable information for selection and adoption of neonicotinoid insecticides for resistance management of TPBs and minimizing toxic risk to foraging bees.

Effects of Calendula officinalis extract on liver histopathology, lipid profile, and oxidative stress in rats submitted to a diet rich in cholesterol and carbohydrates.

To evaluate the modulatory properties of Calendula officinalis L. (Asteraceae) (C. officinalis) extract on cafeteria diet-fed rats. A cafeteria diet was administered ad libitum for 45 days to induce dyslipidemia. Then, the rats were treated with the formulations containing C. officinalis in the doses of 50, 100, and 150 mg/kg or only with the vehicle formulation; the control group received a commercial ration. The cafeteria diet decreased glutathione S-transferase activity and high-density lipoprotein plasmatic levels and damaged the hepatic architecture. The C. officinalis extract was able to reduce lipid infiltration in liver tissue and to modulate oxidative stress and lipid profile markers. The correlations between the variables suggest a pathological connection between oxidative stress markers and serum lipid profile.

Effects of isolated and combined exposures of Boana curupi (Anura: Hylidae) tadpoles to environmental doses of trichlorfon and ultraviolet radiation

The biodiversity collapse strongly affects the amphibian group and many factors have been pointed out as catalytic agents. It is estimated that several events in the amphibian population decline worldwide may have been caused by the interaction of multiple drivers. Thus, this study aimed to evaluate the stressful effects of the exposure to environmental doses of trichlorfon (TCF) pesticide (0.5 μg/L; and an additional 100-fold concentration of 50 µg/L) and ultraviolet radiation (UV) (184.0 kJ/m² of UVA and 3.4 kJ/m² of UVB, which correspond to 5% of the daily dose) in tadpoles of the Boana curupi species (Anura: Hylidae). The isolated and combined exposures to TCF happened within 24 h of acute treatments under laboratory-controlled conditions. In the combined treatments, we adopted three different moments (M) of tadpole irradiation from the beginning of the exposures to TCF (0 h – M1; 12 h – M2; and 24 h – M3). Then, we evaluated tadpole survival, change in morphological characters, induction of apoptotic cells, lipid peroxidation (LPO), protein carbonyl content (PCC), glutathione S-transferase (GST), non-protein thiols (NPSH), and acetylcholinesterase (AChE), as well as the induction of genomic DNA (gDNA) damage. UVB treatment alone resulted in high mortality, along with a high level of apoptosis induction. Both UVA, UVB, and TCF increased LPO, PC, and AChE, while decreased GST activity. Regarding co-exposures, the most striking effect was observed in the interaction between UVB and TCF, which surprisingly decreased UVB-induced tadpole mortality, apoptosis, and gDNA damage. These results reinforce the B. curupi sensitivity to solar UVB radiation and indicate a complex response in face of UVB interaction with TCF, which may be related to activation of DNA repair pathways and/or inhibition of apoptosis, decreasing UVB-induced tadpole mortality.

Comparison of the toxic effects of organic and inorganic arsenic in Caenorhabditis elegans using a multigenerational approach.

Although arsenic (As) is a persistent contaminant in the environment, few studies have assessed its effects over generations, as it requires an animal model with a short lifespan and rapid development, such as the nematode Caenorhabditis elegans. Furthermore, few studies have evaluated the effects of As metabolites such as dimethylarsinic acid (DMAV), and several authors have considered DMA as a moderately toxic intermediate of As, although recent studies have shown that this chemical form can be more toxic than inorganic arsenic (iAs) even at low concentrations. In the present study, we compared the toxic effects of arsenate (AsV) and DMAV in C. elegans over 5 subsequent generations. We evaluated biochemical parameters such as reactive oxygen species (ROS) concentration, the activity of antioxidant defense system (ADS) enzymes such as catalase (CAT) and glutathione-S-transferase (GST), and nonenzymatic components of ADS such as reduced glutathione (GSH) and protein-sulfhydryl groups (P-SH). Exposure to 50μgL-1 of AsV led to an increase in ROS generation and GSH levels together with a decrease in GST activity, while exposure to DMAV led to an increase in ROS levels, with an increase in lipid peroxidation, CAT activity, and a decrease in GSH levels. In addition, both treatments reduced animal growth from the third generation onward and caused disturbances in their reproduction throughout all 5 generations. This study shows that the accumulated effects of DMA need to be considered; it highlights the importance of this type of multigenerational approach for evaluating the effects of organic contaminants considered low or nontoxic.

Trévo abrogates Lead Acetate Neurotoxicity in Male Wistar Rats viz Antiamyloidogenesis, Antiglutaminergic, and Anticholinesterase Activities.

Exposure to lead has been linked to biochemical changes similar to those patients suffering from Alzheimer's disease. Trévo is a phytonutrient-rich product with antiaging and antioxidant properties. To investigate the neuroprotective activity of trévo against lead-induced biochemical changes in male Wistar rats. The study involves 35 animals that were randomly divided into five groups of seven rats each. Group I (Control): Orally administered distilled water; Group II (Induced): Administered 15 mg/kg of lead acetate (PbA) intraperitoneally; Group III (Treatment group): Orally administered 2 mL/kg of trévo for two days before co-administration with PbA for 12 consecutive days; Group IV (Treatment group): Orally administered 5 mL/kg of trévo for two days prior to coadministration with PbA for 12 consecutive days; Group V: Orally administered 5 mL/kg of trévo for 14 consecutive days. Animals were anesthetized with diether and the brain excised and processed for the following biochemical assays: Malonedialdehyde (MDA), glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), glutathione-S-transferase (GT), acetylcholinesterase (AChE), beta-amyloid, glutamate, Na+/K+ ATPase, and glutamate dehydrogenase (GD). PbA caused significant oxidative stress (increased MDA concentration, decreased GSH concentration, suppressed the activity of CAT, SOD), decreased GT activity, increased activity of AChE, increased the concentration of beta-amyloid, and caused glutamate excitotoxicity (increased concentration of glutamate, decreased activity of Na+/K+ ATPase, and GD) in rat brains. Treatment with trévo at the two different doses significantly prevented oxidative damage, beta-amyloid aggregation, glutamate excitotoxicity, and acetylcholine breakdown induced by lead acetate. Our findings added to the reported pharmacological activity of trévo and supported the antiaging potential of trévo.

Effects of selenium treatment on endogenous antioxidant capacity in signal crayfish (Pacifastacus leniusculus)

Selenium is an essential element that plays a role in numerous physiological processes and is critical for the maintenance of a strong endogenous antioxidant system. Previous work by our research group reported that the organophosphate pesticide dimethoate decreased glutathione S-transferase activity (GST) in signal crayfish (Pacifastacus leniusculus) collected from the Boise River (Idaho, USA). The goals of this study were to examine whether: 1) sodium selenite modulated the endogenous antioxidants glutathione (GSH), metallothionein (MT), and glutathione S-transferase (GST), thus suggesting a mechanism of antioxidant activity, 2) dimethoate exposure (pro-oxidant stressor) decreased GST activity in a localized population of signal crayfish collected from the Snake River (Idaho, USA), and 3) investigate whether selenium cotreatment ameliorated the adverse effects of dimethoate on GST activity due to the antioxidant properties associated with selenium. Selenium and dimethoate treatments (and co-treatments) did not modulate GSH or MT concentrations at the doses tested in this study. Furthermore, neither selenium nor dimethoate was factors influencing GST activity, and no interaction was found between the treatments. While our results did not support our predictions, they are suggestive and future studies examining the protective role of selenium in pro-oxidant exposure in this species are warranted. Population-specific responses as well as seasonal variations in endogenous antioxidant expression should be considered in future experiments.

A typical enzyme activity for glutathione conjugation indicates exposure of pacu to pollutants

Abstract Functional enzyme assays to detect sublethal poisoning of Neotropical fish are paramount. Accordingly, we assayed a glutathione S-transferase (GST) activity in liver and kidney cytosols from Piaractus mesopotamicus injected with methyl parathion or benzo[a]pyrene using the substrate 1-chloro-2,4-dinitrobenzene (CDNB), which is the usual substrate for assaying a known general activity of GST. Since the most reactive substrate is required to reveal specific changes in enzyme activity, we also used two alternative substrates, 1,2-dichloro-4-nitrobenzene (DCNB) and ethacrynic acid (ETHA). Activities with CDNB or ETHA did not change. However, assays with DCNB showed that methyl parathion caused a decrease in GST activity in the liver on the 24th, 48th and 96th hour after the injection. DCNB also revealed that GST activity in the liver increased seven days after benzo[a]pyrene injection, coming down to normal after fourteen days. Benzo[a]pyrene, but not methyl parathion, increased the activities with DCNB in cytosol from the kidney seven and fourteen days after the injection. Thus, a decreased liver GST activity assayed with DCNB corresponded to contamination of P. mesopotamicus with methyl parathion. The increase of this GST activity in the liver and the kidney correlates to pacu contamination with polycyclic aromatic hydrocarbons.

Ivermectin: A multilevel approach to evaluate effects in Prochilodus lineatus (Valenciennes, 1836) (Characiformes, Prochilodontidae), an inland fishery species

Ivermectin (IVM) is one of the most widely used antiparasitics worldwide. It is a potent and effective drug for treatment and prevention of internal and external parasitic infections of livestock and humans. IVM is excreted unchanged in manure of treated animals. Thus, residues of IVM may reach aquatic systems, affecting non-target organisms such as fish. Although the presence of IVM in aquatic environments has been reported, a multilevel approach (from cellular to behavioral responses) is necessary to determine the health of exposed organisms and the environmental risks associated. The aim of the present study was to investigate the response of the Neotropical fish Prochilodus lineatus, one of the main target species of South American freshwater fisheries, exposed to environmental concentrations of IVM: low (0.5 μg L−1) and high (1.5 μg L−1). Behavioral responses were assessed in juvenile fish and included water column use, routine swimming, total distance travelled, total activity time and Maximum swimming speed achieved during the escape response. Biochemical/oxidative stress responses assessed included brain acetylcholinesterase (AChE), catalase (CAT) and glutathione S-transferase (GST) activities; total antioxidant competence against peroxyl radicals (ACAP) and lipid oxidative damage (TBARs). Hematological biomarker responses included blood glucose levels, hematocrit, hemoglobin concentration, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, and mean corpuscular volume. Condition factor and hepatosomatic index were also calculated. The lowest IVM concentration caused a significant decrease in GST activity and maximum swimming speed during the escape response. Multivariate analysis with biochemical/stress and behavioral data revealed overall effects of IVM treatments. This multilevel analysis shows detrimental effects related to swimming behavior and predator avoidance which could affect population size and size-structure of P. lineatus. To our knowledge this is the first attempt to assess the effects of IVM on Neotropical fishes using an integrative approach based on biomarkers from different levels of biological organization.

Modulation of endogenous antioxidants by zinc and copper in signal crayfish (Pacifastacus leniusculus)

Metal pollution is a long-standing concern and bioindicators are commonly used in ecotoxicological studies to monitor impacted wildlife populations for evidence of sublethal effects. Significant variation in the response of common biomarkers to metals is reported across taxa, thus necessitating careful characterization in model organisms. In this study, we describe the regulation of glutathione S-transferase (GST), glutathione (GSH), and metallothionein (MT) by zinc chloride (0.6, 0.9, 1.2, 2.4, 4.8, 9.6 μg g−1) and copper chloride (0.6, 0.9, 1.2 μg g−1) in signal crayfish (Pacifastacus leniusculus). Zinc chloride did not alter GST activity relative to controls in the hepatopancreas. Crayfish exposed to copper chloride exhibited decreased GST activity at the lowest dose tested (0.6 μg g−1) with no change observed at the higher doses. GSH did not change in response to either metal when sexes were grouped together. MT concentrations increased in response to zinc (2.4, 4.6, and 9.6 μg g−1 doses) and copper (0.6, 0.9, and 1.2 μg g−1 doses) in gill tissue. In tail tissue, MT increased at the 2.4 and 4.8 μg g−1 zinc chloride doses and all the concentrations of copper tested. Sex-specific differences in endogenous antioxidant expression were also analyzed with no clear patterns emerging. We concluded that these endpoints are sensitive to zinc and copper in signal crayfish, although careful interpretation is needed when applying them in field studies given the variation in responses, non-monotonic dose responses, and differences in biotic and abiotic factors that inevitably exist in different aquatic ecosystems.

Ecotoxicological evaluation of imazalil transformation products on Eisenia Andrei.

Data concerning the toxicity of the transformation products of some pesticides considered emerging contaminants are still incipient. This study aimed to evaluate acute (filter paper contact and avoidance test) and chronic (assays carried out in Red yellow Ultisoil) effects of the transformation products of the fungicide imazalil (IMZ) by heterogeneous photocatalysis (TiO2/UV) in Eisenia andrei. Some endpoints, i.e. biomass variation, disorder in reproduction and avoidance behavior, cytotoxicity (cell density and feasibility), and coelomic fluid (eleocytes and amoebocytes, immune cell) and antioxidant system (catalase (CAT) and glutathione S-transferase (GST)) changes were assessed. The studied degradation times (6, 18, 35 and 90 min) represented 70; 35; 10 and 0% of the initial IMZ concentration (5 mg L-1). No lethality and no significant difference in biomass variations were noted in the acute contact test. Decreased GST and increased CAT activities, as well as cell typing alterations and decreased cell viability and density detected at the 90-min degradation timepoint (PDT-90) indicate direct cytotoxic IMZ transformation product effects. In the avoidance test, no significant earthworm repulsion or attraction was observed. PDT-90 transformation products were responsible for losses in biomass and a reduction in the number of earthworm cocoons and juveniles present in soil. No cytotoxic effects were observed in the long term, although increased CAT and decreased GST activities were observed. Investigations on the relative toxicity of IMZ transformation products are relevant for future discussions regarding the environmental treatment, control and destination of this compound and its derivatives.

Platelet glutathione reductase and glutathione-S-transferase in elderly patients with depression

To compare the activity of platelet glutathione reductase (GR) and glutathione-S-transferase (GST) in elderly patients with depression and in the control group, and to identify a possible relationship between the activity of these enzymes and clinical parameters of the disease. We examined 42 elderly patients (60-86 years old) with depressive episodes of various nosological categories according to ICD-10: a single depressive episode (F32.0, F32.1), a depressive episode in recurrent depressive disorder (RDR - F33.0, F33.1), and a depressive episode in bipolar disorder (BD - F31.3). The GR, GST activity and the severity of depression were assessed twice: before the beginning of the course of 28-day antidepressant therapy (day 0) and on the 28th day of the course of therapy, using the Hamilton Depressive Scale (HAMD-17) and the Hamilton Anxiety Scale (HARS). As compared with the control group, a significant decrease in GST activity was found in patients before and after the course of therapy (p<0.0001 and p<0.0003, respectively), no significant difference in GR activity was found. Significant correlations of the platelet GR activity in patients before thetreatment course with the age of disease manifestation (R= -0.44; p=0.004, inverse correlation) and with its duration (R=0.43, p=0.004, direct correlation), estimated after a 28-day course of therapy. A significant inverse correlation of the baseline (before treatment) GR activity with the HAMD score estimated after the course of therapy (R=-0.440; p=0.009) was found only in women subgroup (n=33). A pilot study has revealed a decrease in platelet GST activity, and a link between platelet GR activity and the severity of depression after a course of therapy. The results obtained indicate the promise of further study of glutathione metabolism enzymes as a biomarker for assessing the state.

Mechanisms of Increased Indoxacarb Toxicity in Methoxyfenozide-Resistant Cotton Bollworm Helicoverpa armigera (Lepidoptera: Noctuidae).

Indoxacarb is an important insecticide for the selective control of Helicoverpa armigera. It can be bioactivated to the more effective N-decarbomethoxylated indoxacarb (DCJW) by esterases in pests. It was observed that both field and laboratory selected populations of H. armigera showed negative cross-resistance between indoxacarb and methoxyfenozide. The Handan population exhibited moderate resistance to indoxacarb, but was susceptible to methoxyfenozide; the Baoding and Yishui populations exhibited moderate resistance to methoxyfenozide, but they were susceptible to indoxacarb. Moreover, the toxicity of indoxacarb was enhanced 1.83-fold in the laboratory methoxyfenozide-resistant H. armigera, and susceptibility to methoxyfenozide was increased 2.81-fold in the laboratory indoxacarb-resistant H. armigera. In vivo, DCJW concentrations in the susceptible and methoxyfenozide-selected (laboratory methoxyfenozide-resistant) populations were 4.59- and 4.31-fold greater than in the indoxacarb-resistant Handan population 1 h after dosing. After 2 h, the highest concentrations of DCJW and indoxacarb appeared in the methoxyfenozide-selected population. Meanwhile, increased carboxyl esterase (CarE) and decreased glutathione S-transferase (GST) activities were observed in the methoxyfenozide-selected population. However, the indoxacarb-selected (laboratory indoxacarb-resistant) and Handan populations showed a higher disappearance of indoxacarb and DCJW, and the activity of cytochrome P450 mono-oxygenase in these populations were significantly increased. This study showed that the improved toxicity of indoxacarb, as observed in the methoxyfenozide-selected H. armigera, was correlated with increased CarE activity, decreased GST activity, and the in vivo accumulation of indoxacarb and DCJW. The significantly increased cytochrome P450 activity and higher disappearance of indoxacarb and DCJW in indoxacarb-resistant H. armigera resulted in the decreased toxicity of indoxacarb.

Insecticidal activity of isolated phenylpropanoids from Alpinia galanga rhizomes against Spodoptera litura

Botanical insecticides as a means of controlling insects present an alternative approach that is safer than the use of synthetic insecticides. The present study identified the insecticidal activity of extracts of the rhizomes of Alpinia galanga (L.) Willd. and seven isolated phenylpropanoids against the second instar of Spodoptera litura Fab. by topical application. The ethyl acetate extract had the highest toxicity on this insect with LD50 values of 1.68 and 1.25 μg/larva after 24 and 48 h posttreatment, respectively. Among the seven phenylpropanoids separated from the ethyl acetate extract, 1′S-1′-acetoxychavicol acetate was identified as the most active compound with LD50 values of 1.63 and 1.40 μg/larva after 24 and 48 h posttreatment, respectively, followed by p-coumaryl diacetate. In addition, the two active compounds decreased glutathione S-transferase activity and increased acetylcholinesterase activity. p-Coumaryl diacetate also decreased carboxylesterase activity.

Evaluation of immunological, inflammatory, and oxidative stress biomarkers in gasoline station attendants

BackgroundGasoline is a complex mixture of saturated and unsaturated hydrocarbons, in which aromatic compounds, such as BTX (benzene, toluene, and xylene) feature as the main constituents. Simultaneous exposure to these aromatic hydrocarbons causes a significant impact on benzene toxicity. In order to detect early alterations caused in gasoline station attendants exposed to BTX compounds, immunological, inflammatory, and oxidative stress biomarkers were evaluated.MethodsA total of 66 male subjects participated in this study. The gasoline station attendants (GSA) group consisted of 38 gasoline station attendants from Rio Grande do Sul, Brazil. The non-exposed group consisted of 28 subjects who were non-smokers and who had no history of occupational exposure. Environmental and biological monitoring of BTX exposure was performed using blood and urine.ResultsThe GSA group showed increased BTX concentrations in relation to the non-exposed group (p < 0.001). The GSA group showed elevated protein carbonyl (PCO) levels and pro-inflammatory cytokines, decreased expression of CD80 and CD86 in monocytes, and reduced glutathione S-transferase (GST) activity compared to the non-exposed group (p < 0.05). BTX levels and trans,trans-muconic acid levels were positively correlated with pro-inflammatory cytokines and negatively correlated with interleukin-10 contents (p < 0.001). Increased levels of pro-inflammatory cytokines were accompanied by increased PCO contents and decreased GST activity (p < 0.001). Furthermore, according to the multiple linear regression analysis, benzene exposure was the only factor that significantly contributed to the increased pro-inflammatory cytokines (p < 0.05).ConclusionsTaken together, these findings show the influence of exposure to BTX compounds, especially benzene, on the immunological, inflammatory, and oxidative stress biomarkers evaluated. Furthermore, the data suggest the relationship among the evaluated biomarkers of effect, which could contribute to providing early signs of damage to biomolecules in subjects occupationally exposed to BTX compounds.

Microplastic exposure represses the growth of endosymbiotic dinoflagellate Cladocopium goreaui in culture through affecting its apoptosis and metabolism.

Microplastics are widespread emerging marine pollutants that have been found in the coral reef ecosystem. In the present study, using Cladocopium goreaui as a symbiont representative, we investigated cytological, physiological, and molecular responses of a Symbiodiniaceae species to weeklong microplastic exposure (Polystyrene, diameter 1.0μm, 9.0×109 particles L-1). The density and size of algal cells decreased significantly at 7d and 6-7d of microplastic exposure, respectively. Chlorophyll a content increased significantly at 7d of exposure, whereas Fv/Fm did not change significantly during the entire exposure period. We observed significant increases in superoxide dismutase activity and caspase3 activation level, significant decrease in glutathione S-transferase activity, but no change in catalase activity during the whole exposure period. Transcriptomic analysis revealed 191 significantly upregulated and 71 significantly downregulated genes at 7d after microplastic exposure. Fifteen GO terms were overrepresented for these significantly upregulated genes, which were grouped into four categories including transmembrane ion transport, substrate-specific transmembrane transporter activity, calcium ion binding, and calcium-dependent cysteine-type endopeptidase activity. Thirteen of the significantly upregulated genes encode metal ion transporter and ammonium transporter, and five light-harvesting protein genes were among the significantly downregulated genes. These results demonstrate that microplastics can act as an exogenous stressor, suppress detoxification activity, nutrient uptake, and photosynthesis, elevate oxidative stress, and raise the apoptosis level through upregulating ion transport and apoptotic enzymes to repress the growth of C.goreaui. These effects have implications in negative impacts of microplastics on coral-Symbiodiniaceae symbiosis that involves C.goreaui.

Toxicity and Oxidative Stress Induced in Spodoptera littoralis (Boisduval) (Lepidoptera: Noctuidae) Treated with Some Insecticides

Integrated pest management of herbivorous pests relies on combining bio-insecticides and chemical insecticides for a satisfactory population control. The present study focused on evaluating the comparative toxicity of five insecticides, with different modes of action, against third and fifth instar larvae of Spodoptera littoralis and their influence on extent of oxidative stress in insect via detecting vitamin C content as well as measuring the activity of phenol oxidase (PO), catalase (CAT), peroxidase (POX), glutathione-S-transferase (GST) antioxidant enzymes compared to control. The results revealed that emamectin benzoate and indoxacarb were the most potent insecticides among the selected insecticides, based on their respective LC50 values. Thiacloprid, indoxacarb and emamectin benzoate significantly reduced Vitamin C content. Almost all treatments significantly increased PO activity. Only emamectin benzoate and Bacillus thuringiensis significantly induced POX activity. Indoxacarb and emamectin benzoate increased CAT activity in both instar larvae, whereas thiacloprid and indoxacarb decreased GST activity. In conclusion, emamectin benzoate and indoxacarb were the most potent insecticides. Activity of oxidative stress biomarkers upon insecticidal pressure has showed variable response.

Anti-hyperlipidemic effects of Campomanesia xanthocarpa aqueous extract and its modulation on oxidative stress and genomic instability in Wistar rats

ABSTRACTThe use of natural products from herbs may be a therapeutic option in dyslipidemia treatment. Campomanesia xanthocarpa (Mart.) O. Berg (Myrtaceae) leaves have been used to decrease cholesterol levels. However, studies to determine activities of this plant on triglycerides metabolism have received little attention. The aim of this study was to examine anti-hyperlipidemic effects of a C. xanthocarpa aqueous leaf extract (CxAE) and assess protective actions against oxidative stress and DNA damage. The tyloxapol-induced hyperlipidemia model was used in Wistar rats. Rats were treated orally with CxAE either 250 or 500 mg/kg/day for 7 days prior to tyloxapol administration. Biochemical parameters, oxidative stress levels, and genomic instability were assessed in several tissues. CxAE decreased cholesterol and triglyceride levels in serum and hepatic and renal DNA damage in tyloxapol-treated rats. There was no marked effect on the micronucleus frequency in bone marrow. The extract increased catalase activity and decreased glutathione S-transferase activity in kidney tissue. CxAE showed anti-hyperlipidemic effects, improved oxidative parameters, and protected DNA against damage induced by tyloxapol-induced hyperlipidemia, suggesting C. xanthocarpa leaves may be useful in preventing dyslipidemias.Abbreviations: ALP: Alkaline phosphatase; ALT: Aspartate aminotransferase; ANOVA: Analysis of variance; AST: Aspartate aminotransferase; Ator: Atorvastatin; CAT: Catalase; Chol: Cholesterol; CxAE: Campomanesia xanthocarpa aqueous extract; GST: Glutathione S-transferase; HDL: High density cholesterol; i.p.: Intraperitoneal; NCE: Normochromatic erythrocyte; PBS: Phosphate buffer solution; PCE: Polychromatic erythrocyte; ROS: Reactive oxygen species; SD: Standard deviation; SOD: Superoxide dismutase; T: Tyloxapol; TBARS: Thiobarbituric acid reacting substances; TG: Triglyceride

#49 Impact of medical history, diet and lifestyle on chromosomal instability in lymphocytes of young couples with trisomy 21 pregnancy

We previously demonstrated that systemic oxidative stress is present in Down syndrome (DS) patients. In the present study we investigated the antioxidant status in the peripheral blood of DS children and teenagers comparing such status before and after an antioxidant supplementation. Oxidative stress biomarkers were evaluated in the blood of DS patients (n = 21) before and after a daily antioxidant intervention (vitamin E 400 mg, C 500 mg) during 6 months. Healthy children (n = 18) without DS were recruited as control group. The activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione S-transferase (GST), gamma-glutamyltransferase (GGT), glucose-6-phosphate dehydrogenase (G6PD) and myeloperoxidase (MPO), as well as the contents of reduced glutathione (GSH), uric acid, vitamin E, thiobarbituric acid reactive substances (TBARS), and protein carbonyls (PC) were measured. Before the antioxidant therapy, DS patients presented decreased GST activity and GSH depletion; elevated SOD, CAT, GR, GGT and MPO activities; increased uric acid levels; while GPx and G6PD activities as well as vitamin E and TBARS levels were unaltered. After the antioxidant supplementation, SOD, CAT, GPx, GR, GGT and MPO activities were downregulated, while TBARS contents were strongly decreased in DS. Also, the antioxidant therapy did not change G6PD and GST activities as well as uric acid and PC levels, while it significantly increased GSH and vitamin E levels in DS patients. Our results clearly demonstrate that the antioxidant intervention with vitamins E and C attenuated the systemic oxidative damage present in DS patients.

The effect of commercial herbicide exposure on the life history and insecticide resistance phenotypes of the major malaria vector Anopheles arabiensis (Diptera: culicidae)

Herbicides, such as atrazine and glyphosate, are common agrochemicals known to pollute surface ground water. As such, aquatic invertebrates associated with agricultural activities can be exposed to varying doses of these xenobiotics. Anopheles arabiensis, a major malaria vector species in southern Africa, is often closely associated with agricultural activities. This study aimed to examine the effects of larval atrazine or glyphosate exposure on larval and adult life history traits on two laboratory strains of An. arabiensis; one insecticide susceptible (SENN), the other selected for resistance (SENN DDT). Atrazine delayed time to pupation in both strains, but markedly more so in SENN DDT. Glyphosate treatment reduced time to pupation in SENN DDT. Larval atrazine exposure decreased adult longevity in SENN, while both herbicide treatments significantly increased adult longevity in SENN DDT. Larval glyphosate exposure was the more potent enhancer of insecticide tolerance in adult mosquitoes. In SENN DDT, it reduced deltamethrin and malathion-induced mortality, and the LT50 s for these insecticides were increased in association with herbicide exposure. Glyphosate exposure also increased the LT50 s for malathion and deltamethrin in SENN. Exposure to both herbicides had contrasting effects on detoxification enzyme activities. Although both increased cytochrome P450 activity, they had opposite effects on those enzymes involved in reactive oxygen species detoxification. Glyphosate decreased glutathione S-transferase activity, but increased catalase activity with atrazine having the opposite effect. This study demonstrates that larval exposure to the herbicides atrazine and glyphosate can affect the insecticide susceptibilities and life history traits of epidemiological importance in An. arabiensis, with glyphosate being the more potent effector of insecticide resistance.

Alteration in cognitive behaviour, brain antioxidant enzyme activity and their gene expression in F1 generation mice, following Cd exposure during the late gestation period: modulation by quercetin.

We investigated whether in-utero Cd(II) chloride exposure of the dams between 14th to 21st day of gestation affects memory and learning, oxidative stress, antioxidant enzyme activity and their gene expression in brain of the pups in their adulthood. In the Morris water maze, cadmium (Cd) exposure impaired spatial memory which was reversed following co-treatment with quercetin (100mg/kg). In the passive avoidance paradigm, retention memory was adversely affected but was significantly reversed by co treatment with quercetin (25, 50, 100mg/kg). The malondialdehyde and catalase (CAT) levels and glutathione-S-transferase (GST) activity were increased significantly in Cd-treated group, but were reversed by quercetin (all doses). The gene expression for CAT and GST in brain tissue of Cd treated animals also increased many folds as compared to the control, and this effect was decreased on co-treatment with quercetin (all doses), thus matching with the respective enzyme activities. Quercetin (25mg/kg) when co-treated with Cd caused a decrease in GST activity compared to control, which points towards a complex interplay with oxidative free radicals and promoters and transcription factors. Thus, Cd exposure during late gestation causes impaired spatial and retention memory in the next generation which may be due to alteration of activity as well as gene expression of the antioxidant enzymes, CAT and GST. Quercetin may offer some protection of memory impairment probably by modulating these effects.