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.

Interspecific differences in oxidative DNA damage after hydrogen peroxide exposure of sea urchin coelomocytes

Interspecific comparison of DNA damage can provide information on the relative vulnerability of marine organisms to toxicants that induce oxidative genotoxicity. Hydrogen peroxide (H2O2) is an oxidative toxicant that causes DNA strand breaks and nucleotide oxidation and is used in multiple industries including Atlantic salmon aquaculture to treat infestations of ectoparasitic sea lice. H2O2 (up to 100 mM) can be released into the water after sea lice treatment, with potential consequences of exposure in nontarget marine organisms. The objective of the current study was to measure and compare differences in levels of H2O2-induced oxidative DNA damage in coelomocytes from Scottish sea urchins Echinus esculentus, Paracentrotus lividus, and Psammechinus miliaris. Coelomocytes were exposed to H2O2 (0-50 mM) for 10 min, cell concentration and viability were quantified, and DNA damage was measured by the fast micromethod, an alkaline unwinding DNA method, and the modified fast micromethod with nucleotide-specific enzymes. Cell viability was >92% in all exposures and did not differ from controls. Psammechinus miliaris coelomocytes had the highest oxidative DNA damage with 0.07 ± 0.01, 0.08 ± 0.01, and 0.07 ± 0.01 strand scission factors (mean ± SD) after incubation with phosphate-buffered saline, formamidopyrimidine-DNA glycosylase, and endonuclease-III, respectively, at 50 mM H2O2. Exposures to 0.5 mM H2O2 (100-fold dilution from recommended lice treatment concentration) induced oxidative DNA damage in all three species of sea urchins, suggesting interspecific differences in vulnerabilities to DNA damage and/or DNA repair mechanisms. Understanding impacts of environmental genotoxicants requires understanding species-specific susceptibilities to DNA damage, which can impact long-term stability in sea urchin populations in proximity to aquaculture farms.

Ozonolysis of Permethrin in the Atmosphere: Mechanism, Kinetics, and Evaluation of Toxicity

Pyrethroid, a pesticide widely used worldwide, could mimic, block, or synergize the effects of endogenous hormones in humans or mammals after entering into the atmosphere and after being sprayed and applied in large quantities. This research aims to study the mechanism, kinetics, and eco-toxicity evaluation of the ozonolysis of permethrin (PER)-one of the typical pyrethroid (type I) pesticides. Existing experimental studies only predicted that ozonolysis of PER could generate a cycloperoxy analogue of PER (IM13-1-11), and the reaction mechanism has not yet been completed. To make up for the lack of experimental results, the 13 primary reaction pathways of PER and ozone, as well as the subsequent reactions of Criegee intermediates with small molecules such as NOx, COx, SO2, and O2, have been studied to propose new reaction paths by quantum chemical calculations in this work. We calculated the total reaction rate constant of PER and ozone at 298 K and 1 atm based on the calculated thermodynamic data and the transition state theory (TST), which was compared with the experimental values to prove the reliability of our results. Based on the quantitative structure and activity relationship, we predicted the acute and chronic toxicity of PER and its products of ozonolysis to three representative organisms-fish, daphnia, and green algae to avoid animal experiments. The results show that ozonolysis products of PER are still extremely harmful to the environment and should be taken seriously, although the products have less toxicity than PER.

Regulatory effects of quercetin on testicular histopathology induced by cyanide in Wistar rats

Several causes of infertility have been identified, and several papers have documented some compounds that cause infertility. One of the compounds reported to be toxic to the reproductive system is cyanide. In the management of infertility, various mechanisms ranging from synthetic drugs, natural products and supplements have been employed. Quercetin is an antioxidant supplement that has been used in the treatment of a variety of ailments. This work is aimed at investigating the role of quercetin in attenuating spermato-toxicity and testicular-histopathology induced by cyanide.

Seventy-two (72) male wistar rat (weight 190 g ± 10 g) were divided into nine groups (n = 8) except for groups 4 and 5 with (n = 16). Group 1 (control) received physiological saline while Groups 2 and 3 received 0.5 and 1 mg/kg body weight (bwt) cyanide respectively for 56 days, groups 4 and 5 received 0.5 and 1 mg/kg bwt cyanide respectively for 30 days. At day 30, eight animals were sacrificed from Groups 4 and 5 and the remaining eight (8) rats were subdivided into groups (6 and 7) and were given 20 and 40 mg/kg bwt of quercetin respectively for twenty-six days. Co-administration of cyanide and quercetin at a dose of 0.5 mg/kg cyanide +20 mg/kg quercetin and 1 mg/kg cyanide +40 mg/kg quercetin were given to group 8 and 9 respectively for 56 days.

Significant decreases in sperm parameters (count, motile and normal sperm) and increases in malondiadehyde concentration were observed in the cyanide treated groups. Testicular histoarchitecture showed few to no spermatozoa in the lumen of rats treated with cyanide. All these effects were attenuated by quercetin.

In conclusion, quercetin regulates testicular histopathology induced by cyanide in Wistar rats. Data from this work suggests potential preventive or therapeutic applications of quercetin for individuals subjected to cyanide environmental pollution.

Pyrethroid based pesticides - chemical and biological aspects

Human and animal welfare primarily depends on the availability of food and surrounding environment. Over a century and half, the quest to identify agents that can enhance food production and protection from vector borne diseases resulted in the identification and use of a variety of pesticides, of which the pyrethroid based ones emerged as the best choice. Pesticides while improved the quality of life, on the other hand caused enormous health risks. Because of their percolation into drinking water and food chain and usage in domestic settings, humans unintentionally get exposed to the pesticides on a daily basis. The health hazards of almost all known pesticides at a variety of doses and exposure times are reported. This review provides a comprehensive summation on the historical, epidemiological, chemical and biological (physiological, biochemical and molecular) aspects of pyrethroid based insecticides. An overview of the available knowledge suggests that the synthetic pyrethroids vary in their chemical and toxic nature and pose health hazards that range from simple nausea to cancers. Despite large number of reports, studies that focused on identifying the health hazards using doses that are equivalent or relevant to human exposure are lacking. It is high time such studies are conducted to provide concrete evidence on the hazards of consuming pesticide contaminated food. Policy decisions to decrease the residual levels of pesticides in agricultural products and also to encourage organic farming is suggested.

Genetic and Environmental Factors in Parkinson's Disease Converge on Immune Function and Inflammation

Idiopathic Parkinson's disease (iPD) is a movement disorder characterized by the degeneration of dopaminergic neurons and aggregation of the protein α-synuclein. Patients with iPD vary in age of symptom onset, rate of progression, severity of motor and non-motor symptoms, and extent of central and peripheral inflammation. Genetic and environmental factors are believed to act synergistically in iPD pathogenesis. We propose that environmental factors (pesticides and infections) increase the risk for iPD via the immune system and that the role of PD risk genes in immune cells is worthy of investigation. This review highlights the major PD-relevant genes expressed in immune cells and key environmental factors that activate immune cells and, alone or in combination with other factors, may contribute to iPD pathogenesis. By reviewing these interactions, we seek to enable the future development of immunomodulatory approaches to prevent or delay onset of iPD. © 2020 International Parkinson and Movement Disorder Society.

Acute and chronic toxicity of deltamethrin, permethrin, and dihaloacetylated heterocyclic pyrethroids in mice

BACKGROUND

Pyrethroids, a class of insecticides, that act on the nervous system of insects. Frequent consumption of foods with pyrethroid residues increase the risk of developmental and neurological diseases in humans. Assessing the toxicity of novel synthetic pyrethroids to mammals is also critical to the development of agrochemicals.

RESULTS

Using mice as models, the acute and chronic toxicity of deltamethrin, permethrin, dihaloacetylated pyrethroids to mammals was researched by gavage administration. Acute toxicity assessment displayed that the median lethal dose (LD₅₀ ) of deltamethrin, permethrin and dihaloacetylated heterocyclic pyrethroids DCA-O, DCA-01, and DCA-11 tested were greater than 500 mg/kg of weight. Furthermore, chronic toxicity assessment demonstrated that deltamethrin, permethrin caused epidermal damage near the genitals, while dihaloacetylated heterocyclic pyrethroids DCA-O, DCA-01, and DCA-11 showed no relevant symptoms. However, both the acute and chronic toxicity assessment suggested that pyrethroids exposure induced mice loss weight. Additionally, the elevated plus maze (EPM) test showed that pyrethroids caused anxiety-like behaviors and no motor defects in Kunming mice. Beside, during the sucrose preference test (SPT), 60-day pyrethroids exposure increased excitatory behaviors in mice. However, the neurochemical studies displayed that pyrethroids exposure increased the total amount of glutamate (Gln), glutamine (Glu) and γ-aminobutyric acid (GABA) in the mice's blood.

CONCLUSION

Pyrethroids exposure induced weight loss in mice, although the acute oral toxicity of deltamethrin, permethrin and dihaloacetylated heterocyclic pyrethroids DCA-O, DCA-01, and DCA-11 was low. However, regarding chronic toxicity, deltamethrin, permethrin and dihaloacetylated heterocyclic pyrethroids DCA-O, DCA-01, and DCA-11 induced anxiety-like behaviors, excitatory behaviors, Gln-Glu-GABA circulatory dysfunction in blood. Particularly, deltamethrin, though permethrin also had reproductive toxicity. © 2020 Society of Chemical Industry.

Synthesis, insecticidal activity, resistance, photodegradation and toxicity of pyrethroids (A review)

Pyrethroids are a class of highly effective, broad-spectrum, less toxic, biodegradable synthetic pesticides. However, despite the extremely wide application of pyrethroids, there are many problems, such as insecticide resistance, lethal/sub-lethal toxicity to mammals, aquatic organisms or other beneficial organisms. The objectives of this review were to cover the main structures, synthesis, steroisomers, mechanisms of action, anti-mosquito activities, resistance, photodegradation and toxicities of pyrethroids. That was to provide a reference for synthesizing or screening novel pyrethroids with low insecticide resistance and low toxicity to beneficial organisms, evaluating the environmental pollution of pyrethroids and its metabolites. Besides, pyrethroids are mainly used for the control of vectors such as insects, and the non-target organisms are mammals, aquatic organisms etc. While maintaining the insecticidal activity is important, its toxic effects on non-target organisms should be also considered. Pyrethroid resistance is present not only in insect mosquitoes but also in environmental microorganisms, which results in anti-pyrethroids resistance (APR) strains. Besides, photodegradation product dibenzofurans is harmful to mammals and environment. Additionally, pyrethroid metabolites may have higher hormonal interference than the parents. Particularly, delivery of pyrethroids in nanoform can reduce the discharge of more toxic substances (such as organic solvents, etc.) to the environment.

Environmental aircraft noise aggravates oxidative DNA damage, granulocyte oxidative burst and nitrate resistance in Ogg1-/- mice

Background: Large epidemiological studies point towards a link between the incidence of arterial hypertension, ischaemic heart disease, metabolic disease and exposure to traffic noise, supporting the role of noise exposure as an independent cardiovascular risk factor. We characterised the underlying molecular mechanisms leading to noise-dependent adverse effects on the vasculature and myocardium in an animal model of aircraft noise exposure and identified oxidative stress and inflammation as central players in mediating vascular and cardiac dysfunction. Here, we studied the impact of noise-induced oxidative DNA damage on vascular function in DNA-repair deficient 8-oxoguanine glycosylase knockout (Ogg1^-/-) mice.Methods and results: Noise exposure (peak sound levels of 85 and mean sound level of 72 dB(A) applied for 4d) caused oxidative DNA damage (8-oxoguanine) and enhanced NOX-2 expression in C57BL/6 mice with synergistic increases in Ogg1^-/- mice (shown by immunohistochemistry). A similar pattern was found for oxidative burst of blood leukocytes and other markers of oxidative stress (4-hydroxynonenal, 3-nitrotyrosine) and inflammation (cyclooxygenase-2). We observed additive impairment of noise exposure and genetic Ogg1 deficiency on endothelium-independent relaxation (nitroglycerine), which may be due to exacerbated oxidative DNA damage leading to leukocyte activation and oxidative aldehyde dehydrogenase inhibition.Conclusions: The finding that chronic noise exposure causes oxidative DNA damage in mice is worrisome since these potential mutagenic lesions could contribute to cancer progression. Human field studies have to demonstrate whether oxidative DNA damage is also found in urban populations with high levels of noise exposure as recently shown for workers with high occupational noise exposure.

The role of the enzyme-modified comet assay in in vivo studies

The in vivo comet assay is an established genotoxicity test, with an OECD test guideline, but in its standard form it measures only DNA strand breaks. Including in the assay an additional step, in which the DNA is incubated with a lesion-specific enzyme, can provide important information about the nature of the DNA damage. Formamidopyrimidine DNA glycosylase, 8-oxoguanine DNA glycosylase or endonuclease III are commonly used in the in vitro genotoxicity test and in human biomonitoring to detect oxidised bases, but in vivo applications are rarer. A systematic literature search has identified a total of 60 papers that report such in vivo experiments, testing a variety of agents. In many cases, strand breaks were not seen, but significant levels of enzyme-sensitive sites were induced - indicating a mechanism of action involving oxidative stress. Compounds such as methyl methanesulfonate (MMS) or ethyl methanesulfonate (EMS) could be used as positive controls in both the standard and the enzyme-modified in vivo comet assays.

Acute Exposure to Permethrin Modulates Behavioral Functions, Redox, and Bioenergetics Parameters and Induces DNA Damage and Cell Death in Larval Zebrafish

Permethrin (PM) is a synthetic pyrethroid insecticide widely used as domestic repellent. Damage effects to nontarget organisms have been reported, particularly in the early stages of development. Studies indicate redox unbalance as secondary PM effect. Therefore, our goal was to investigate the acute PM effects on larval zebrafish. Larvae (6 days postfertilization) were exposed to PM (25–600 μg/L) during 24 hours, and 50% lethal concentration was estimated. For subsequent assays, the sublethal PM concentrations of 25 and 50 μg/L were used. PM increased anxiety-like behaviors according to the Novel Tank and Light-Dark tests. At the molecular level, PM induced increased ROS, which may be related to the increased lipid peroxidation, DNA damage, and apoptosis detected in PM-exposed organisms. In parallel, upregulation of the antioxidant system was detected after PM exposure, with increased superoxide dismutase, glutathione S-transferase and glutathione reductase activities, and thiol levels. The increased of Nrf2 target genes and the activation of an electrophile response element-driven reporter Tg(EPRE:LUC-EGFP) suggest that the Nrf2 pathway can mediate a fast response to PM, leading to antioxidant amplification. By using high-resolution respirometry, we found that exposure to PM decreased the oxygen consumption in all respiratory stages, disrupting the oxidative phosphorylation and inhibiting the electron transfer system, leading to decrease in bioenergetics capacity. In addition, PM led to increases of residual oxygen consumption and changes in substrate control ratio. Glucose metabolism seems to be affected by PM, with increased lactate dehydrogenase and decreased citrate synthase activities. Taken together, our results demonstrated the adverse effects of acute sublethal PM concentrations during larval development in zebrafish, causing apparent mitochondrial dysfunction, indicating a potential mechanism to redox unbalance and oxidative stress, which may be linked to the detected cell death and alterations in normal behavior patterns caused by acute PM exposure.

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.

Permethrin pesticide induces NURR1 up-regulation in dopaminergic cell line: Is the pro-oxidant effect involved in toxicant-neuronal damage?

The mechanisms associated to the development of neurodegeneration due to pesticide exposure are not clear yet. In this study we evaluated how permethrin pesticide (PERM) can influence the Nurr1 gene and protein expression, and if a pro-oxidant activity of the pesticide contributes to up-regulation of Nurr1 in a dopaminergic cell line. Incubation of PC12 cells with 1μM PERM for 72h, leads to over expression of Nurr1 gene. This effect occurs with both corn oil and extra virgin olive oil (EVO) used to solubilize the toxicant. In order to investigate if the Nurr1 up-regulation induced by PERM, was associated to the pro-oxidant activity of the pesticide, anti-oxidants as glutathione (GSH), tocotrienols (TOC) and Electrolyzed Reduced Water (ERW) were tested. RT-PCR of Nurr1 showed that its up-regulation was significantly reduced in the presence of antioxidants, especially by addition of ERW. Western-blot analysis reveals that ERW was able to counterbalance the up-regulation of Nurr1 protein induced by permethrin exposure.

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.

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.

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.

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.

Erythrocyte antioxidants enzymes imbalance following subcutaneous pyrethroid treatments in rats of different sex

Permethrin and deltamethrin are insecticides used all over the world in agriculture to control pests. The aim of this work is to investigate the effects of subcutaneous permethrin and/or deltamethrin treatments on erythrocyte antioxidant enzymes activity in rats of different sex. The results obtained show that permethrin decreases SOD and GPx activity in female rats, while it increases SOD activity in male rats. Deltamethrin treatment reduces GPx activity in male rats, while permethrin has a similar effect but only for short time treatments. A catalase activity decrease was observed in both sexes following pyrethroid treatment but when both the pyrethroids were administrated in male rats, the enzyme activity has increased. In conclusion, this study points out for the first time the importance of rat gender on erythrocyte antioxidant enzymes, which are influenced not only by the length and the type of insecticide treatment but importantly by sex.

Effect of permethrin insecticide on rat polymorphonuclear neutrophils

Polymorphonuclear neutrophils are professional phagocytes whose efficacy depends on a multicomponent NADPH oxidase for generating superoxide anions and bacterial killing. They can be primed and activated by different agents that can impair oxidative burst and phagocytosis with opposite effects: reduced capability to destroy bacteria or hyperactivation that induces the generation of large quantities of toxic reactive oxygen species, which can damage surrounding tissue and participate in inflammation. The present study was designed to evaluate the effect of sub-chronic (60 days) permethrin treatment (1/10 DL(50)) on rat polymorphonuclear neutrophils respiratory burst. The results show that permethrin treatment increases superoxide anion production (33 times) and the activity of hydrogen peroxide-myeloperoxidase system (67 times). In vitro experiments suggest that this effect can be related to permethrin priming and to physico-chemical changes at the plasma membrane level of neutrophils. The antioxidant supplementation with Vitamin E and coenzyme Q(10) can protect against the abnormal respiratory burst in rat treated with permethrin. The in vitro studies show that neutrophil apoptosis begins soon after 1h of incubation with permethrin (0.725% of total cells) or its metabolites (3-phenoxybenzyl alcohol, 3-phenoxybenzaldehyde and 3-phenoxybenzoic acid 1.36, 2.26 and 1.3 of total cells, respectively) and that the level of apoptotic cells is very low. In conclusion, immunotoxicity of permethrin measured in rats could prompt future studies on the consequences of chronic insecticide exposure.