Purine Bases Oxidation and Repair Following Permethrin Insecticide Treatment in Rat Heart Cells

Comparative Proteomics of Resistant and Susceptible Strains of Frankliniella occidentalis to Abamectin

Western flower thrips, Frankliniella occidentalis (Thysanoptera: Thripidae) is an invasive agricultural pest with developed resistance to abamectin in some strains due to frequent treatment with the pesticide. In this study, we examined differentially expressed proteins (DEPs) between abamectin-resistant (AbaR; under abamectin selective pressure) and susceptible strains (AbaS; without abamectin selective pressure) of F. occidentalis. Proteins were isolated from second instar larvae of both strains and separated via two-dimensional polyacrylamide gel electrophoresis. Nano-flow liquid chromatography-tandem mass spectrometry identified selected protein spot features. From 70 DEPs, 43 spot features were identified: A total of 23 showed an increase in abundance, and 20 were down-regulated in response to abamectin pressure. The enzymatic and structural proteins were classified into the functional groups of macromolecular metabolisms, signaling and cellular processes, immune system, genetic information processing, and exoskeleton-related proteins. The up-regulation of exoskeleton-related proteins may contribute to forming a thicker cuticle, potentially hindering abamectin penetration, which is an interesting finding that needs further investigation. Two novel proteins, triacylglycerol lipase and cuticle protein CPF 2, were only expressed in AbaR. This work provides insights into abamectin resistance mechanisms in F. occidentalis, which will provide important information for developing insecticide resistance management approaches for this pest.

Chronic inhalation exposure to the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) alters cardiac collagen in Wistar rats

INTRODUCTION

2,4-dichlorophenoxyacetic acid (2,4-D) is one of the most used in the world and exposure to herbicides can affect animals and humans, causing toxic effects that include cardiotoxicity. This is the first study to evaluate cardiac remodeling after experimental simulation of environmental exposure by chronic inhalation (6 months) to the herbicide 2,4-D.

METHODS

Thirty male Wistar rats were exposed to two different concentrations of the 2,4-D formulation (low - 187.17 mg/m3; and high - 467.93 mg/m3) and the control group exposed to nebulization of chloride solution 0.9% sodium. Inhalation exposure lasted 6 months. Mice hearts were collected for histology.

RESULTS

There was a difference between exposure concentrations in relation to the increase in cardiac collagen (P < 0.0001). In mice exposed to a low dose of 2,4-D and a decrease in the fractal dimension of cardiac collagen in the high dose of 2, 4-D (P = 0.010).

DISCUSSION

This study shows that chronic inhalation exposure to 2,4-D induces cardiotoxicity in rats, characterized by extracellular matrix reorganization and changes in collagen levels, highlighting the impact of the exposure route on cardiac outcomes.

CONCLUSION

There was no difference in relation to anatomical parameters, cardiomyocyte area, collagen types I and III and analysis of arteriole thickness. Chronic exposure at different doses to the 2,4D herbicide had the potential to cause damage to cardiac remodeling by altering cardiac collagen in rats.

Toxic effects of the synthetic pyrethroid permethrin on the hematological parameters and antioxidant enzyme systems of the freshwater fish Cyprinus carpio L

This study investigated changes in hematological and antioxidant parameters of carp exposed to two different doses of synthetic pyrethroid permethrin (control, vehicle, 10 ppm, and 20 ppm) for two different periods (4 days and 21 days). Hematological analyses were then performed on a veterinary Ms4 (Melet Schloesing, France) blood counter using commercially available kits (Cat. No. WD1153). Buege and Aust for MDA, Luck for CAT, McCord and Frivovich for SOD, Lawrence and Burk methods for GSH-Px were used to determine antioxidant parameters. Decreases in RBC count, Hb amount, Hct value, granulocyte ratios, and increases in total WBC and lymphocyte ratios were statistically significant in both dose groups treated with permethrin compared to the control group (p < 0.05). However, there was no statistically significant difference in monocyte ratios (p > 0.05). Overall, permethrin exposure caused an increase in MDA levels in the liver and gill tissues of carp in both dose and duration groups compared to the control group. Also, no statistically significant difference between the two dose groups in the liver tissue was observed in terms of duration (p > 0.05). Nonetheless, the increase in MDA levels in PERM10 and PERM20 dose groups in the gill tissues over 21 days was statistically significant (p < 0.05). Furthermore, permethrin exposure increased CAT, SOD, and GSH-Px enzyme activities in the gill tissue, while impacting in the opposite direction the liver tissue. Finally, regarding MDA, CAT, SOD, and GSH-Px levels, the control, and control acetone dose groups of all experimental groups were observed to be similar (p > 0.05). As a result, permethrin produced a toxic effect on Cyprinus carpio, triggering changes in blood parameters and inducing the antioxidant enzyme system.

Cardiotoxicity of some pesticides and their amelioration

Pesticides are used to control pests that harm plants, animals, and humans. Their application results in the contamination of the food and water systems. Pesticides may cause harm to the human body via occupational exposure or the ingestion of contaminated food and water. Once a pesticide enters the human body, it may create health consequences such as cardiotoxicity. There is not enough information about pesticides that cause cardiotoxicity in the literature. Currently, there are few reports that summarized the cardiotoxicity due to some pesticide groups. This necessitates reviewing the current literature regarding pesticides and cardiotoxicity and to summarize them in a concrete review. The objectives of this review article were to summarize the advances in research related to pesticides and cardiotoxicity, to classify pesticides into certain groups according to cardiotoxicity, to discuss the possible mechanisms of cardiotoxicity, and to present the agents that ameliorate cardiotoxicity. Approximately 60 pesticides were involved in cardiotoxicity: 30, 13, and 17 were insecticides, herbicides, and fungicides, respectively. The interesting outcome of this study is that 30 and 13 pesticides from toxicity classes II and III, respectively, are involved in cardiotoxicity. The use of standard antidotes for pesticide poisoning shows health consequences among users. Alternative safe medical management is the use of cardiotoxicity-ameliorating agents. This review identifies 24 ameliorating agents that were successfully used to manage 60 cases. The most effective agents were vitamin C, curcumin, vitamin E, quercetin, selenium, chrysin, and garlic extract. Vitamin C showed ameliorating effects in a wide range of toxicities. The exposure mode to pesticide residues, where 1, 2, 3, and 4 are aerial exposure to pesticide drift, home and/or office exposure, exposure due to drinking contaminated water, and consumption of contaminated food, respectively. General cardiotoxicity is represented by 5, whereas 6, 7, 8 and 9 are electrocardiogram (ECG) of hypotension due to exposure to OP residues, ECG of myocardial infraction due to exposure to OPs, ECG of hypertension due to exposure to OC and/or PY, and normal ECG respectively.

Trans-ovo permethrin exposure affects growth, brain morphology and cardiac development in quail

Permethrin is a commonly used, highly effective pesticide in poultry agriculture, and has recently been trialed in conservation efforts to protect Galápagos finch hatchlings from an invasive ectoparasite. Although permethrin is considered safe for adults, pesticides can have health consequences when animals are exposed during early life stages. The few studies that have examined permethrin's effects in embryonic chicks and rats have shown hydrocephaly, anencephaly, reduced cellular energy conversion, and disruption of developing heart muscle. To test whether trans-ovo exposure of permethrin affects early development in birds, we exposed Japanese quail (Coturnix japonica) eggs to cotton treated with 1% permethrin that was incorporated into nests in two amounts (0.2, 0.8 g), each with a paired untreated cotton control group. When measured on incubation Day 15, we found permethrin-treated developing birds were smaller and showed signs of microcephaly, although mortality rates were the same. Despite no difference in heart mass, ventricular tissue was less compact, cardiac arteries were reduced and heart rates were slower in permethrin-treated birds. Differences in heart development were also observed at 5 days of incubation, indicating that abnormalities are present from early in cardiac development. Future studies are needed to examine permethrin's effects on developmental pathways and to determine if these effects persist after hatching to affect offspring health. This study provides evidence that permethrin can cross the eggshell to cause non-lethal but adverse effects on embryonic development, and studies should look beyond hatching when monitoring the efficacy of permethrin on wild bird populations.

High-Throughput Screening to Identify Chemical Cardiotoxic Potential

Cardiovascular (CV) disease is one of the most prevalent public health concerns, and mounting evidence supports the contribution of environmental chemicals to CV disease burden. In this study, we performed cardiotoxicity profiling for the Tox21 chemical library by focusing on high-throughput screening (HTS) assays whose targets are associated with adverse events related to CV failure modes. Our objective was to develop new hypotheses around environmental chemicals of potential interest for adverse CV outcomes using Tox21/ToxCast HTS data. Molecular and cellular events linked to six failure modes of CV toxicity were cross-referenced with 1399 Tox21/ToxCast assays to identify cardio-relevant bioactivity signatures. The resulting 40 targets, measured in 314 assays, were integrated via a ToxPi visualization tool and ranking system to prioritize 1138 chemicals based upon formal integration across multiple domains of information. Filtering was performed based on cytotoxicity and generalized cell stress endpoints to try and isolate chemicals with effects specific to CV biology, and bioactivity- and structure-based clustering identified subgroups of chemicals preferentially affecting targets such as ion channels and vascular tissue biology. Our approach identified drugs with known cardiotoxic effects, such as estrogenic modulators like clomiphene and raloxifene, anti-arrhythmic drugs like amiodarone and haloperidol, and antipsychotic drugs like chlorpromazine. Several classes of environmental chemicals such as organotins, bisphenol-like chemicals, pesticides, and quaternary ammonium compounds demonstrated strong bioactivity against CV targets; these were compared to existing data in the literature (e.g., from cardiomyocytes, animal data, or human epidemiological studies) and prioritized for further testing.

Early impairment of epigenetic pattern in neurodegeneration: Additional mechanisms behind pyrethroid toxicity

Permethrin is a synthetic pyrethroid extensively used as anti-woodworm agent and for indoor and outdoor pest control. The main route of human exposure is through fruit, vegetable and milk intake. Low dosage exposure to permethrin during neonatal brain development (from postnatal day 6 to postnatal day 21) leads to dopamine decrease in rat striatum nucleus, oxidative stress and behavioural changes linked to the development of Parkinson's like neurodegeneration later in life. The aim of this study was to evaluate the expression of genes involved in the dopaminergic pathway and epigenetic regulatory mechanisms in adolescent rats treated with permethrin during neonatal brain development. Furthermore, in order to shed light on the mechanisms associated with molecular impairments, in silico studies were performed. The outcomes show increased expression of genes related to the dopamine-synthesis pathway (Nurr1, Th, Snca), epigenetics (TET proteins and Mecp2) and exposure to toxicants (Pon1 and Pon2) in adolescent rats compared with control group. Furthermore, increased global 5mC and 5hmC levels were observed in the DNA extracted from striatum of early-life treated rats in comparison with controls. FAIRE-qPCR analysis shows that permethrin induces an enrichment of chromatin-free DNA at the level of Th and Nurr1 promoters, and ChIP-qPCR reveals a significant reduction in methylation levels at H3K9me3 position at both Th and Nurr1 promoter regions. In silico studies show that permethrin competes for the same two binding sites of known NURR1 agonists, with a lower binding free energy for permethrin, suggesting an important durable association of permethrin with the orphan receptor. Moreover, alpha-synuclein shows a strong affinity for NURR1, corroborating previous experimental outcomes on the interactions between them. This study focuses on an emerging role of early-life exposure to environmental pollutants in the regulation of late onset diseases through intriguing mechanisms that change crucial epigenetic patterns starting from adolescent age.

Epigenetic Memory of Early-Life Parental Perturbation: Dopamine Decrease and DNA Methylation Changes in Offspring

Early-life exposure (from postnatal day 6 to postnatal day 21) to permethrin has been associated with long-term development of dopaminergic neurodegeneration in rats. Here, we first investigated if the dopamine decrease observed following early postnatal exposure to permethrin, an oxidative stressor, can impair the dopamine level in the brain of their untreated offspring. Secondly, we evaluated whether this adverse event affects the epigenome of both directly exposed rats (F0) and their untreated offspring (F1). The results show that early-life exposure to the stressor is associated with changes in global DNA methylation and hydroxymethylation in adult age. Furthermore, parental exposure leads to a significant reduction in dopamine level in the offspring (F1) born from parents or just mothers early-life treated (72.72% and 47.35%, respectively). About 2/3 of pups from exposed mothers showed a significant reduction in dopamine level compared to controls. Global DNA methylation and hydroxymethylation impairment was associated with the F1 pups that showed reduced dopamine. This study provides pivotal evidences on intergenerational effects of postnatal exposure to permethrin emphasizing that this xenobiotic can influence the epigenetic memory of early-life parental perturbations disturbing offspring health.

Pesticides and cardiotoxicity. Where do we stand?

Cardiovascular diseases are among the most significant causes of mortality in humans. Pesticides toxicity and risk for human health are controlled at a European level through a well-developed regulatory network, but cardiotoxicity is not described as a separate hazard class. Specific classification criteria should be developed within the frame of Regulation (EC) No 1272/2008 in order to classify chemicals as cardiotoxic, if applicable to avoid long-term cardiovascular complications. The aim of this study was to review the cardiac pathology and function impairment due to exposure to pesticides (i.e. organophosphates, organothiophisphates, organochlorines, carbamates, pyrethroids, dipyridyl herbicides, triazoles, triazines) based on both animal and human data. The majority of human data on cardiotoxicity of pesticides come from poisoning cases and epidemiological data. Several cardiovascular complications have been reported in animal models including electrocardiogram abnormalities, myocardial infarction, impaired systolic and diastolic performance, functional remodeling and histopathological findings, such as haemorrhage, vacuolisation, signs of apoptosis and degeneration.

Nonoccupational Exposure to Pyrethroids and Risk of Coronary Heart Disease in the Chinese Population

Pyrethroids and the metabolites have been frequently observed in the environment. Animal data suggests that pyrethroids can induce adverse effect on the cardiovascular system but there are no human studies examining pyrethoids exposure as a risk for coronary heart disease (CHD). We analyzed three nonspecific pyrethroids metabolites in urine and studied the association with CHD risk. A total of 72 CHD patients and 136 healthy subjects were recruited in Shanxi province in China from 2013 to 2014 by matching age and gender. The median concentrations of urinary cis-CDDA (cis-3-(2,2-dichlorovinyl)-2,2-dimethyl cyclopropane carboxylic acid), trans-CDDA (trans-3-(2,2-dichlorovinyl)-2,2-dimethyl cyclopropane carboxylic acid) and 3-PBA (3-phenoxybenzoic acid) among healthy subjects were 1.03, 0.42, 0.74 μg/L respectively, while the median concentrations of the three metabolites among CHD patients were 1.93, 1.07, 1.09 μg/L respectively, significantly higher than healthy subjects. Upper tertile of urinary pyrethroid metabolites were associated with an increased risk of CHD compared with the lowest tertile (cis-CDDA: OR_T3vsT1 = 6.86, 95% CI: 2.76-17.06, p-trend = 0.000; trans-CDDA: OR_T3vsT1 = 6.94; 95% CI: 2.80-17.19; p-trend =0.000; 3-PBA: OR_T3vsT1 = 3.62; 95% CI: 1.48-8.88; p-trend = 0.009; total pyrethroid metabolites: OR_T3vsT1 = 4.55; 95% CI: 1.80-11.54; p-trend = 0.002). This study provides information on pyrethroids exposure in China and reveals a possible positive association between pyrethroids exposure and the risk of coronary heart disease.

Permethrin-induced oxidative stress and toxicity and metabolism. A review

Permethrin (PER), the most frequently used synthetic Type I pyrethroid insecticide, is widely used in the world because of its high activity as an insecticide and its low mammalian toxicity. It was originally believed that PER exhibited low toxicity on untargeted animals. However, as its use became more extensive worldwide, increasing evidence suggested that PER might have a variety of toxic effects on animals and humans alike, such as neurotoxicity, immunotoxicity, cardiotoxicity, hepatotoxicity, reproductive, genotoxic, and haematotoxic effects, digestive system toxicity, and cytotoxicity. A growing number of studies indicate that oxidative stress played critical roles in the various toxicities associated with PER. To date, almost no review has addressed the toxicity of PER correlated with oxidative stress. The focus of this article is primarily to summarise advances in the research associated with oxidative stress as a potential mechanism for PER-induced toxicity as well as its metabolism. This review summarises the research conducted over the past decade into the reactive oxygen species (ROS) generation and oxidative stress as a consequence of PER treatments, and ultimately their correlation with the toxicity and the metabolism of PER. The metabolism of PER involves various CYP450 enzymes, alcohol or aldehyde dehydrogenases for oxidation and the carboxylesterases for hydrolysis, through which oxidative stress might occur, and such metabolic factors are also reviewed. The protection of a variety of antioxidants against PER-induced toxicity is also discussed, in order to further understand the role of oxidative stress in PER-induced toxicity. This review will throw new light on the critical roles of oxidative stress in PER-induced toxicity, as well as on the blind spots that still exist in the understanding of PER metabolism, the cellular effects in terms of apoptosis and cell signaling pathways, and finally strategies to help to protect against its oxidative damage.

Efficacy of naringenin against permethrin-induced testicular toxicity in rats

Permethrin (PM), a synthetic pyrethroid insecticide, has broad toxicity spectra. We aimed to investigate the effects of PM on the testes of adult albino rats, examine the recovery response and evaluate the efficacy of naringenin (NG) supplementation. Adult male albino rats were randomly assigned to five groups of six each: control, NG (50 mg/kg), PM (70 mg/kg), recovery (after subsequent withdrawal of PM) and NG-PM group. All treatments were given by oral gavage for 6 weeks and another 3 weeks for the recovery group. At the time of sacrifice, each testis was weighed. Biochemical analysis of epididymal sperm count and serum testosterone level was performed. Testes were processed for histological, ultrastructural and c-Kit immunohistochemical study. PM toxicity was evidenced by a highly significant decrease in testicular weight, epididymal sperm count and serum testosterone level compared to control. Furthermore, testicular structure abnormalities and reduced c-Kit immunoreactions were observed. Stoppage of PM in the recovery group partially reversed PM-induced changes. There was a mild decrease in testicular weight and biochemical parameters compared to control. The structure of seminiferous tubules was partially retained. The NG-PM group showed an overall improvement in testicular weight and biochemical alterations which were confirmed by light and electron microscopic examination. In conclusion, PM induced testicular toxicity, which was ameliorated by NG co-administration. However, stoppage of PM exposure was associated with partial recovery.

Permethrin and its metabolites affect Cu/Zn superoxide conformation: fluorescence and in silico evidences

Permethrin and its metabolites affect the structure and activity of Cu/Zn superoxide dismutase (SOD), as it results from intrinsic fluorescence, 8-ANS fluorescence techniques and in silico studies.

Effect of permethrin, anthracene and mixture exposure on shell components, enzymatic activities and proteins status in the Mediterranean clam Venerupis decussata

Anthracene (ANT) and permethrin (PER) are two of the more toxic compounds reaching the marine environment. This study aimed to determine the impact of these molecules on Venerupis decussata, an economically important species cultured on the Tunisian coast. Shell structure and its possible transformation upon exposure to the two contaminants were studied by X-ray diffraction and gravimetric analyses. Results revealed a phase transition in shell composition from aragonite to calcite after PER exposure, to a mixture of PER and ANT (Mix) but not for ANT alone. Catalase (CAT), superoxide dismutase (SOD) and glutathione transferase (GST) activities were determined in digestive gland and gills after exposure to ANT, PER and Mix to assess the impact of the contamination on the oxidative status of V. decussata. Enzyme activities increased in the digestive gland after PER treatment and in the gills after ANT treatment. PER exposure significantly reduced the levels of free thiols and increased levels of carbonylated proteins in the digestive gland, as compared to controls. In contrast, ANT exposure significantly reduced free thiols and increased the number of carbonylated proteins in the gills. Mix induced additive effects as measured by both enzymatic and proteomic approaches. The present study suggests that PER has a strong effect on shell structure; that PER and ANT exposure generate compound-dependent oxidative stress in the tissues of V. decussata and that a mixture of the two compounds has synergistic effects on biochemical response.

Organic contaminants in bats: trends and new issues

Exposure to contaminants, often pesticides, has been implicated as a major factor contributing to decreases in bat populations. Bats provide essential ecosystem services and a sustained, thriving population is vital for ecosystem health. Understanding issues threatening their survival is crucial for their protection and conservation. This paper provides the first review for 12years on organic pollutants in bats and aims to investigate trends and any new issues impacting bat resilience. Organochlorine (OC) pesticides have been reported most often, especially in the older literature, with the dichlorodiphenyltrichloroethane (DDT) metabolite, dichlorodiphenyldichloroethylene (DDE), present at highest concentrations in tissues analyzed. The OC pesticide concentrations reported in bat tissues have declined significantly since the late 1970s, presumably as a result of restrictions in use. For example, DDE study mean concentrations over time periods 1970-1980, 1981-1999 and 2000-2013 ranged from 2.6-62, 0.05-2.31, 0.08-0.19ppm wet weight, respectively. Exposure, however, still occurs from remaining residues, many years after the compounds have been actively used. In recent years (2000-2013), a range of other organic chemicals have been reported in bat tissues including brominated flame retardants (polybrominated diphenyl ether at a mean concentration of 2.9ppm lipid weight) and perfluorinated compounds (perfluorooctanyl sulfonate at a mean concentration 0.09ppm wet weight). The persistent organic compounds concentrate in tissues with higher fat content notably back-depot fat. Numerous factors influence exposure, residues detected and concentrations in different individuals, species and tissues which must be understood to provide meaningful assessment of the impacts of exposure. Exposure can lead to not only acute and lethal impacts, but also physiological sub-lethal and chronic effects, often linked to the annual cycle of fat deposition and withdrawal. Current challenges for bat conservation include collation of a more extensive and standardized database of bat exposure, especially to current use pesticides and emerging contaminants, and better prediction and definition of toxicity end points notably for the sub-lethal effects. Understanding sub-lethal effects will be of greater importance for sustaining populations in the longer-term.

Early life permethrin treatment leads to long-term cardiotoxicity

Environmental, nutritional or hormonal influences in early life may have long-term effects changing homeostatic processes and physiological parameters in adulthood. NF-kB and Nrf2, two of the main transcription factors regulating genes involved in pro-inflammatory and antioxidant responses respectively, can be modified by various stimuli. NF-kB controls immediate early genes and is required for cardiomyocyte hypertrophic growth, while Nrf2 protects the heart from oxidative stress-induced cardiovascular complications. The aim of this study was to investigate the impact of early life permethrin treatment (1/50 of LD50, from 6th to 21st day of life) on the development of cardiotoxicity in 500-day-old rats. Nrf2 and NF-kB gene expression, calcium level and heart surface area were chosen as biomarkers of toxicity. Six candidate reference genes were first examined and GAPDH resulted the most stable one for RT-qPCR. The comparative expression analysis of the target genes showed 1.62-fold increase in Nrf2 mRNA level, while the NF-kB mRNA in treated rats was not significantly changed compared to control ones. A significant decrease in heart surface area was observed in treated rats (296.59 ± 8.09, mm(2)) with respect to the control group (320.86 ± 4.93, mm(2)). Finally, the intracellular calcium influx in heart of early life treated rats increased 4.33-fold compared to the control one. In conclusion, early life pesticide exposure to low doses of permethrin insecticide, has long-term consequences leading to cardiac hypotrophy, increased calcium and Nrf2 gene expression levels in old age.

Exercise-induced heart mitochondrial cholesterol depletion influences the inhibition of mitochondrial swelling

The significance of the reduction of the cholesterol pool in heart mitochondria after exercise is still unknown. Recently, published data have suggested that cholesterol may influence the components of mitochondrial contact site and affect mitochondrial swelling. Therefore, the aim of this study was to determine whether the decreased cholesterol content in heart mitochondria caused by prolonged swimming may provoke changes in their bioenergetics and result in an increased resistance to calcium chloride-induced mitochondrial swelling. Male Wistar rats were divided into a sedentary control group and an exercise group. The rats exercised for 3 h, burdened with an additional 3% of their body weight. Their hearts were removed immediately after completing the exercise. The left ventricle was divided and used for experiments. Mitochondrial cholesterol content, membrane fluidity and mitochondrial bioenergetics were measured in the control and exercised rat heart mitochondria. To assess whether mitochondrial modifications are linked to disruption of lipid microdomains, methyl-β-cyclodextrin, a well-known lipid microdomain-disrupting agent and cholesterol chelator, was applied to the mitochondria of the control group. Cholesterol depletion, increased membrane fluidity and increased resistance to calcium chloride-induced swelling were observed in postexercise heart crude mitochondrial fraction. Similar results were achieved in control mitochondria treated with 2% methyl-β-cyclodextrin. All of the mitochondrial bioenergetics parameters were similar between the groups. Therefore, the disruption of raft-like microdomains appears to be an adaptive change in the rat heart following exercise.

Imbalance in redox system of rat liver following permethrin treatment in adolescence and neonatal age

The effect of different permethrin treatments on the redox system of rat liver, is presented. Two types of oral administration were chosen: (i) sub-chronic treatment (1/10 of LD50 for 60 days) during adolescence (5 weeks old) and (ii) sub-acute treatment (1/44 of LD50 for 15 days) during early life (from postnatal days 6-21). The results show that adolescent permethrin treatment induces damage to the liver redox system, increasing lipid and protein peroxidation and reducing membrane fluidity in the hydrophilic--hydrophobic region of the bilayer. In addition, glutathione peroxidase (GPx) and GSH levels resulted decreased, while glutathione transferase (GST) and catalase (CAT) levels increased. The rats treated in early life with permethrin and sacrificed in adult age, showed less signs of damage compared to those exposed during adolescence in which lipid peroxidation was increased by 32%, whereas for the first group the raise was only 11%. Moreover, fluidity improved in the deeper hydrophobic membrane region of the treated group, while the level of CAT was significantly lower compared to the control one. Although sub-chronic treatment increased CAT and GST and decreased GPx and GSH levels, the present data suggest that a shorter exposure to permethrin during neonatal age decreased CAT level and it could represent an important risk factor for the onset of long-term liver damage.

Early life permethrin exposure induces long-term brain changes in Nurr1, NF-kB and Nrf-2

Pesticide exposure during brain development represents an important risk factor for the onset of brain-aging processes. Here, the impact of permethrin administered to rats from 6th to 21st day of life, at a dose near to "no observed adverse effect level" (NOAEL), was studied when animals reached 500 day-old. The permethrin treatment induced a decrease in Nurr1 gene expression in striatum, an increase in hippocampus and cerebellum, while the protein level changed only in striatum where it was increased. NF-kB p65 gene expression was increased in cerebellum, while its protein level augmented in cerebellum and in prefrontal cortex and decreased in hippocampus of treated rats compared to control ones. Nrf-2 gene expression resulted significantly higher only in cerebellum of treated animals. The results suggest that early life permethrin treatment induces long-lasting effects leading to dopaminergic neuronal disorders, monitored by Nurr1 alteration. Moreover the impairment of NF-kB and Nrf-2, important for the balance between pro- and anti-inflammatory systems, confirms that the neonatal permethrin treatment can influence genes involved with the onset of brain-ageing processes.

Lipid composition is a determinant for human defensin HNP1 selectivity

Human neutrophilpeptide 1 (HNP1) is a human defensin with antimicrobial activity against different bacteria (both Gram-positive and negative), fungi, and viruses. HNP1 is stored in the cytoplasmic azurophilic granules of neutrophils. To elucidate the mode of action of this antimicrobial peptide, studies based on its lipid selectivity were carried out. Large unilamellar vesicles with different lipid compositions were used as biomembranes model systems (mammal, fungal, and bacterial models). Changes on the intrinsic fluorescence of HNP1 upon membrane binding/insertion show that HNP1 has quite distinct preferences for mammalian and fungal membrane model systems. HNP1 showed low interaction with glucosylceramide rich membranes, but high sterol selectivity: it has a higher partition for ergosterol-containing membranes (as fungal membranes) and lower interaction with cholesterol-containing membranes (as in mammalian cells). These results reveal that lipid selectivity is a determinant step for HNP1 action. Fluorescence quenching data obtained using acrylamide indicate that HNP1 interacts with membranes without a full insertion in the lipid bilayer. Generalized polarization of laurdan indicates a change in membrane fluidity in the presence of HNP1 for POPC membranes but not for ergosterol-enriched membranes.

The Effects of Taurine on Permethrininduced Cytogenetic and Oxidative Damage in Cultured Human Lymphocytes

Permethrin (PM) is a common pyrethroid pesticide used to control pests in agriculture, forestry, horticulture, health care, homes, and textile industry. It is confirmed as a strong mutagen in animals and humans. Taurine (TA) is an amino acid found in mammalian tissues that protects the cell against DNA damage. In this study, we investigated whether supplementation of human lymphocyte cultures with TA (in the concentrations of 25 μg mL-1, 50 μg mL-1and 100 μg mL-1) provided any protection against PM toxicity applied in the concentration of 200 μg mL-1. Genotoxicity was assessed using the micronucleus (MN) and sister chromatid exchanges (SCE) tests. In addition, we measured the total antioxidant capacity (TAC) and total oxidative stress (TOS) levels in the plasma to determine oxidative effects. PM increased SCE and MN levels and altered TAC and TOS levels. TA alone did not affect SCE and MN levels compared to controls, regardless of the concentration applied. In addition, it increased TAC levels without changing TOS levels. Moreover, it significantly buffered the negative cytogenetic and oxidative effects induced by PM in a clear dose-dependent manner. In conclusion, this study is the first to evidence the beneficial effects of TA against PM-induced DNA and oxidative damagesin vitro.

Olive leaf extract modulates permethrin induced genetic and oxidative damage in rats

Permethrin is a common synthetic chemical, widely used as an insecticide in agriculture and other domestic applications. The previous reports indicated that permethrin is a highly toxic synthetic pyrethroid pesticide to human and environmental health. Therefore, the present experiment was undertaken to determine the effectiveness of olive leaf extract in modulating the permethrin induced genotoxic and oxidative damage in rats. The animals used were broadly divided into four (A, B, C and D) experimental groups. Group A rats served as control animals and received distilled water intraperitoneally (n = 5). Groups B and C rats received intraperitoneal injections of permethrin (60 mg kg(-1) b.w) and olive leaf extract (500 mg kg(-1) b.w), respectively. Group D rats received permethrin (60 mg kg(-1) b.w) plus olive leaf extract (500 mg kg(-1) b.w). Rats were orally administered their respective feed daily for 21 days. At the end of the experiment rats were anesthetized and serum and bone marrow cell samples were obtained. Genotoxic damage was assessed by micronucleus and chromosomal aberration assays. Total antioxidant capacity and total oxidant status were also measured in serum samples to assess oxidative status. Treatment of Group B with permethrin resulted in genotoxic damage and increased total oxidant status levels. Permethrin treatment also significantly decreased (P < 0.05) total antioxidant capacity level when compared to Group A rats. Group C rats showed significant increases (P < 0.05) in total antioxidant capacity level and no alterations in cytogenetic parameters. Moreover, simultaneous treatments with olive leaf extract significantly modulated the toxic effects of permethrin in Group D rats. It can be concluded that olive leaf extract has beneficial influences and could be able to antagonize permethrin toxicity. As a result, this investigation clearly revealed the protective role of olive leaf extract against the genetic and oxidative damage by permethrin in vivo for the first time.

Early life permethrin insecticide treatment leads to heart damage in adult rats

Early life environmental exposure to xenobiotics could represent a critical period for the onset of permanent alterations in the structure and function of different organs. Cardiovascular diseases can be related to various factors including environmental toxicants. The aim of the present study was to evaluate the effect of early life permethrin treatment (1/50 LD(50), from 6th to 21st day of life) on heart of adult rats. Increased DNA damage, decreased heart cell membrane fluidity, increased cholesterol content, protein and lipid oxidation were measured in heart cells from adult rats treated with permethrin during the neonatal period with respect to control rats. Moreover, the same group showed higher levels of cholesterol, IL-1β, IL-2, IFN-γ, rat-Rantes and IL-10 cytokines and decreased albumin content in plasma. Lower cholesterol levels and perturbation in the phospholipid lateral diffusion together with decreased GSH levels and increased GPx activity were measured in heart mitochondria of the treated group. Our findings support the evidence that the neonatal period has a critical role in the development of heart disease in adulthood. We hypothesize that the alterations observed in adult rats could depend on epigenetic changes that occurred during this period which influence gene expression throughout the rat's life, leading to alterations of certain parameters related to cardiac function.