Residue of insecticides in foodstuff and dietary exposure assessment of Brazilian citizens

Understanding Role of Pesticides in Development of Parkinson's Disease: Insights from Drosophila and Rodent Models

Parkinson's disease is a neurodegenerative illness linked to ageing, marked by the gradual decline of dopaminergic neurons in the midbrain. The exact aetiology of Parkinson's disease (PD) remains uncertain, with genetic predisposition and environmental variables playing significant roles in the disease's frequency. Epidemiological data indicates a possible connection between pesticide exposure and brain degeneration. Specific pesticides have been associated with important characteristics of Parkinson's disease, such as mitochondrial dysfunction, oxidative stress, and α-synuclein aggregation, which are crucial for the advancement of the disease. Recently, many animal models have been developed for Parkinson's disease study. Although these models do not perfectly replicate the disease's pathology, they provide valuable insights that improve our understanding of the condition and the limitations of current treatment methods. Drosophila, in particular, has been useful in studying Parkinson's disease induced by toxins or genetic factors. The review thoroughly analyses many animal models utilised in Parkinson's research, with an emphasis on issues including pesticides, genetic and epigenetic changes, proteasome failure, oxidative damage, α-synuclein inoculation, and mitochondrial dysfunction. The text highlights the important impact of pesticides on the onset of Parkinson's disease (PD) and stresses the need for more research on genetic and mechanistic alterations linked to the condition.

Pesticides and Polychlorinated Biphenyls in Milk and Dairy Products in Croatia: A Health Risk Assessment

The aim of this study was to evaluate contamination levels and the frequency of detection of organochlorine (OCPs) and organophosphate pesticides (OPPs), pyrethroids, carbamates and polychlorinated biphenyls (seven PCB congeners) in a total of 534 samples of cow's, sheep's and goat's milk and dairy products from Croatia. Concentrations above the limit of quantification (LOQ) were measured for fourteen OCPs, nine OPPs, six pyrethroids, one carbamate and PCBs with a total of 172 results, and no concentrations exceeded the maximal residue levels defined by the European Union. The mean concentrations of pesticides and the sum of seven PCBs were determined in the ranges 0.92-17.4 μg/kg and 1.38-2.74 μg/kg. Pesticides were quantified in 27% of samples, and seven PCBs were quantified in 5.23% of samples. Among the three pesticide groups, the highest numbers of quantified results were found for OCPs (12.1-20.8%). The highest frequencies of detection were found for the sum of 4,4'-dichlorodiphenyltrichloroethane and its isomers (DDTs), hexachlorobenzene and seven PCBs. The sum of seven PCBs was quantified within the range of 3.3-6.67% of samples per milk type and dairy products. Among the OPPs, the highest frequency of detection was found for chlorpyrifos in cow's milk. Based on the estimated daily intakes, chronic risk characterisation showed no risk for adults or ten-year-old children for the consumption of cow's milk and dairy products.

Maternal exposure to deltamethrin during pregnancy and lactation impairs neurodevelopment of male offspring

Deltamethrin (DM) is a highly effective and widely used pyrethroid pesticide. It is an environmental factor affecting public and occupational health and exerts direct toxic effects on the central nervous system. As the major target organs for neurotoxicity of DM, the hippocampus and the cerebellum are critical to the learning and motor function. Pregnant Wistar rats were randomly divided into four groups and gavaged at doses of 0, 1, 4or 10 mg/kg/d DM from gestational day (GD) 0 to postnatal day (PN) 21. The PC12 cells were selected to further verify the regulatory mechanisms of DM on the neurodevelopmental injury. We found that maternal exposure to DM caused learning, memory and motor dysfunction in male offspring. Maternal exposure to DM induced the decrease in the density of hippocampal dendritic spines in male offspring through the reduced expression of M1 mAchRs, which in turn reduced the mediated AKT/mTOR signaling pathway, contributing to the inhibition of dynamic changes of GluA1. Meanwhile, DM exposure inhibited the BDNF/TrkB signaling pathway, thereby reducing phosphorylation of stathmin and impairing cerebellar purkinje cell dendrite growth and development. Taken together, maternal exposure to DM during pregnancy and lactation could impair neurodevelopment of male offspring.

Distribution of Pesticides and Polychlorinated Biphenyls in Food of Animal Origin in Croatia

Pesticides and polychlorinated biphenyls (PCBs) are persistent environmental pollutants. When entering the food chain, they can represent a public health problem due to their negative effects on health. In this study, concentrations of organochlorine pesticides (OCPs), organophosphate pesticides (OPPs), pyrethroids, carbamates, and PCBs-a total 73 compounds-were determined in a total of 2268 samples of fat tissues (beef, pork, sheep, goat, poultry, game, horse, rabbit) and processed fat, meat, and processed meat products collected in Croatia during an 8-year period. In fatty tissues, 787 results exceeded the limits of quantification (LOQ): 16 OCPs, eight OPPs, six pyrethroids, one carbamate, and seven PCBs. The most positive results in fat samples were found for OCPs, with a frequency of quantification in the range of 57.5-87.5%. Hexachlorobenzene (HCB) and dichlorodiphenyldichloroethylene (DDE) were quantified in the highest percentages, in the ranges of 5.5-66.7% and 5.4-55.8%. Concentrations above the MRL values were determined for chlorpyrifos in pork fat and for resmethrin in six fat samples and one pâté. In 984 samples of meat and meat products, only 62 results exceeded the LOQ values. The highest frequency of quantification was determined for OCPs (25 samples), of which 40% were DDT isomers (60% DDE). Frequency quantifications of PCBs in fat samples were between 7.23 and 36.7%. An evaluation of the health risk assessment showed that the consumption of fat, meat, and meat products does not pose a threat to consumer health, since all EDI values were well below the respective toxicological reference values.

Nanoemulsion-based plant essential oil formulations: in vitro evaluation of pesticidal activity against ectoparasites in poultry

Ectoparasite infestations significantly impact the health and productivity of poultry. Chemical applications, although common for pest control, lead to pesticide residues and parasite resistance in poultry. Nanoemulsion-based plant essential oil formulations (NEOFs) provide a promising alternative for controlling poultry ectoparasites. This study aimed to assess the efficacy of NEOFs from clove, cinnamon, and turmeric essential oils (EOs) against ectoparasites, Menopon gallinae and Megninia ginglymura, under laboratory conditions. The toxicity and repellent properties of the NEOFs were examined, with the major chemical compounds of the EOs analyzed using chromatography mass spectrometer. Results identified eugenol as the dominant component in clove and cinnamon EOs (84.60 and 75.19%, respectively), while turmerone (68.46%) was the major compound in turmeric EO. NEOFs with clove:cinnamon:turmeric ratios of 4:0:0, 2:2:0, and 2:0:2 had particle size of 20.76 nm, 20.66 nm, and 89.56 nm, respectively, while those based on eugenol and turmerone standards had sizes <21.0 nm. In addition, NEOFs at 0.3% concentration with ratios of 4:0:0 and 2:2:0 achieved full control of both ectoparasites. These formulas demonstrated exceptional potency in exterminating ectoparasites, with LC50 and LC90 at <0.160 and <0.250%, respectively, 6 h after treatments. Furthermore, both NEOFs showed higher repellence responses in M. gallinae compared to M. ginglymura. The toxicities of these NEOFs were comparably effective against both parasites, showing no significant difference compared with chemical insecticide treatment. Therefore, further research will explore the practicality of using clove and cinnamon-derived NEOFs under farm conditions.

Target and non-target analytical method for potential hazardous substances in livestock and pet hair using liquid- and gas chromatography quadrupole time-of-flight mass spectrometry

Extraction using acetonitrile and water and quadrupole time-of-flight mass spectrometry (LC and GC-QTOF/MS) techniques were used to screen for potential hazardous substances in livestock and pet hair. In addition, LC-MS/MS and GC-MS/MS techniques were used for verification of the analytical method and quantitative analysis of pesticides, veterinary drugs, mycotoxins and antioxidants in hair. Optimized sample preparation involves extracting 0.05 g of sample with 0.6 mL of ACN and 0.4 mL of distilled water. In addition, the two layers were separated by adding 0.1 g of NaCl. Then, both the ACN and water layers were analyzed by LC-TOF/MS, and the ACN layer was analyzed by GC-TOF/MS. Most of the matrix effects of livestock and pet hair were less than 50%, but some matrices and components showed high results, so matrix matching correction was applied for more precise quantification. Method validation was performed for 394 constituents (293 pesticides, 93 veterinary drugs, 6 mycotoxins and 2 preservatives) in dog, cat, cow and pig hair and chicken and duck feathers. All components showed good linearity (r2 ≥0.98) in the developed assay. The quantification limit of all compounds was set at 0.02 mg/kg, which is the lowest level that satisfies the recovery rate standard. The recovery experiment was repeated 8 times at 3 concentrations. Most of the components were extracted with the ACN layer, and the recovery rate was 63.35-119.98%. In order to confirm the efficiency of extracting harmful substances from actual samples, 30 hairs of livestock and pets were screened.

Chlorpyrifos induces apoptosis and necroptosis via the activation of CYP450s pathway mediated by nuclear receptors in LMH cells

Chlorpyrifos (CPF), an organophosphorus pesticide, is detected commonly in environments, where it is thought to be highly toxic to non-target organisms. However, the mechanism of CYP450s pathway mediated by nuclear receptors on CPF-induced apoptosis and necroptosis at the cellular level and the effect of CPF on the cytotoxicity of the chicken hepatocarcinoma cell line (LMH) has also not been reported in detail. Therefore, this experiment aims to explore whether CPF can improve apoptosis and necroptosis in LMH cells by activating the nuclear receptors/CYP450s axis. LMH cells, the subject of this study, were exposed to 5 μg/mL, 10 μg/mL, and 15 μg/mL doses of CPF. With the increase of CPF concentration, the increase of nuclear receptor level led to the up-regulation of CYP450s activity. With the massive production of ROS, the expression of apoptotic pathway genes (Bax, Caspase9, and Caspase3) enhanced, while Bcl-2 expression dropped sharply. The expression of programmed necroptosis genes (RIPK1, RIPK3, and MLKL) heightened, and Caspase8 reduced considerably. In short, our data suggests that excessive activation of nuclear receptors and CYP450s induced by CPF promotes ROS production, which directs apoptosis and programmed necroptosis in LMH cells.

Pesticide exposure among Czech adults and children from the CELSPAC-SPECIMEn cohort: Urinary biomarker levels and associated health risks

Current-use pesticides (CUP) are extensively applied in both agricultural and urban settings. Exposure occurs mainly via the dietary pathway; however, other pathways such as inhalation or skin contact are also important. In this study, urinary levels of 12 CUP metabolites were investigated among 110 parent-child pairs during two seasons of 2020. Metabolites of pyrethroids (3-PBA, t/c-DCCA), chlorpyrifos (TCPY), and tebuconazole (TEB-OH) were detected in more than 60% of the samples. Chlorpyrifos metabolite was found at the highest concentration and tebuconazole was detected in almost all samples. CUP urinary metabolite levels were significantly higher in children in comparison to adults, except for tebuconazole, which was similar in both groups. In children, winter samples had significantly higher concentrations of pyrethroid and chlorpyrifos metabolites in comparison to the summer samples, but in adults, only chlorpyrifos metabolite concentrations were higher in the winter. No association between CUP urinary metabolite levels and proximity/surface of agricultural areas around residences was observed. Based on our findings, we suspect that CUP exposure is mainly driven by diet and that the effect of environmental exposure is less significant. Daily Intakes were estimated with three possible scenarios considering the amount of the metabolite excreted in urine and were compared to Acceptable Daily Intake values. Using a realistic scenario, exposure to chlorpyrifos exhibited the highest health risk, but still within a safe level. The Acceptable Daily Intake was exceeded only in one child in the case of cypermethrin. The cumulative risk assessment of pesticide mixtures having an effect on the nervous system, based on the total margin of exposure calculations, did not indicate any risk. The overall risk associated with pesticide exposure in the observed population was low. However, the risk observed using the worst-case scenario suggests the need for continuous evaluation of human exposure to such compounds, especially in children.

Chlorpyrifos Occurrence and Toxicological Risk Assessment: A Review

Chlorpyrifos (CPF) was the most frequently used pesticide in food production in the European Union (EU) until 2020. Unfortunately, this compound is still being applied in other parts of the world. National monitoring of pesticides conducted in various countries indicates the presence of CPF in soil, food, and water, which may have toxic effects on consumers, farmers, and animal health. In addition, CPF may influence changes in the population of fungi, bacteria, and actinomycete in soil and can inhibit nitrogen mineralization. The mechanisms of CPF activity are based on the inhibition of acetylcholinesterase (AChE) activity. This compound also exhibits reproductive toxicity, neurotoxicity, and genotoxicity. The problem seems to be the discrepancy between the actual observations and the final conclusions drawn for the substance's approval in reports presenting the toxic impact of CPF on human health. Therefore, this influence is still a current and important issue that requires continuous monitoring despite its withdrawal from the market in the EU. This review traces the scientific reports describing the effects of CPF resulting in changes occurring in both the environment and at the cellular and tissue level in humans and animals. It also provides an insight into the hazards and risks to human health in food consumer products in which CPF has been detected.

Assessment of pesticide use and pesticide residues in vegetables from two provinces in Central Vietnam

Pesticide residue in food, especially in vegetables, is one of the important parameters to assess food safety. This study evaluates the pesticide use in vegetables from two provinces in Central Vietnamand and present data on pesticides detected in vegetables sampled from the sites. The potential health risk associated with the contamination of four commonly used pesticides in different vegetables is also discussed. Both household surveys and monitoring campaigns were conducted. The survey showed that improper pesticide application, storage, and waste disposal prevailed at the study sites. Only 20% of the respondent were aware of pesticide toxicity. As a result, pesticides were detected in 81% out of 290 vegetable samples collected at harvesting time. Up to 23% of samples had pesticide residues above the Maximum Residue Limit values. The highest total pesticide concentration quantified in vegetables in Thua Thien Hue was 11.9 mg/kg (green onions), and in Quang Binh was 38.6 mg/kg (mustard greens). Median residue levels of individual pesticides in vegetables ranged from 0.007 to 0.037 mg/kg. Among the ten target pesticides, cypermethrin, difenoconazole, and fenobucarb were detected at the highest frequencies (72%, 41%, and 37%, respectively). Pesticide residues varied between seasons at both study provinces. Pesticide contamination in the wet season was significantly higher than in the dry season. This study also discovered a potential health risk associated with fipronil residues in vegetables in Thua Thien Hue province. The paper provides recommendations for mitigation measures (both technological and social) in reducing potential health risks linked to pesticide use in vegetables in the region.

Evaluating the consequences of household hazardous waste diversion on public health and ecological risks of leachate exposure

Household hazardous waste (HHW) includes approximately 1% of municipal solid waste (MSW), which is related to the lack of efficient separate collection schemes co-disposed with MSW in many countries worldwide. In this research, the effect of HHW diversion on leachate quality and consequent reduction in risks to the environment and human health was investigated. In this regard, physicochemical parameters of MSW leachate samples with and without hazardous fraction were characterized. Next, leachate pollution index (LPI) and associated risks were assessed. The results showed that the source separation of HHW decreases the LPI value by 13.48% and improves the potential of leachate for biological treatment, leading to a reduction in leachate treatment costs and complexity. Based on risk assessment results, HHW diversion could lower cancer risks of organic compounds and heavy metals to acceptable levels for adults and children. Moreover, by the source-separating of HHW, hazard indices for aquatic and terrestrial bioassays reduced by 41.5 and 36%, respectively. Furthermore, despite the comparatively low generated amount of HHW, this fraction should be emphasized due to its unintended effects for public health and the environment.

Lifelong exposure to pyrethroid insecticide cypermethrin at environmentally relevant doses causes primary ovarian insufficiency in female mice

Pyrethroids are a class of widely used insecticides. Our recent epidemiological study of Chinese women reported that pyrethroid exposure was positively associated with the risk of primary ovarian insufficiency (POI). In this study, we utilized cypermethrin (CP), the most frequently detected pyrethroid in the environment, to recognize how lifelong and low-dose exposure to pyrethroids affects ovarian functions and the underlying mechanism(s). Female mice were exposed to CP at doses of human dietary intake of 6.7 μg/kg/day, an acceptable daily intake (ADI) of 20 μg/kg/day, or the chronic reference dose (RfD) of 60 μg/kg/day, starting from gestational day 0.5 until 44-week-old. We assessed effects on fertility, serum hormone levels, ovarian follicular development and ovarian transcriptomic profiles. Chronic exposure to CP at doses of ADI and RfD caused a significant reduction in the size of the primordial follicle pool on postnatal day (PND) 5 and the number of all types of follicles in 44-week-old mice, lower estrogen and higher gonadotropin levels, as well as decreased fertility. Significant increase in apoptosis and decrease in cell proliferation were observed in CP-exposed ovarian follicles from PND 5 and 44-week-old mice. Ovarian transcriptomic data showed that the pro-apoptotic protein BMF and the cell cycle inhibitor p27 were significantly up-regulated in CP-exposed ovaries. Cyp17a1, Cyp19a1 and Hsd17b1 genes involved in the key steps of steroidogenesis were down-regulated in the ovaries of female mice exposed to CP. This study first reported that lifelong exposure to CP at doses of ADI or RfD caused an ovarian phenotype similar to human POI in female mice and provided a mechanistic explanation. Our findings suggest that lifelong exposure to pyrethroids of low doses, which are recommended as 'safe' dosages, may have a significant impact on the ovarian health of female mammals and humans.

DNA damage in a Chilean population exposed to pesticides and its association with PON1 (Q192R and L55M) susceptibility biomarker

The active ingredients in pesticides are known to be genotoxic that can cause mutations, chromosomal aberrations, or other types of DNA damage. Early detection of genotoxicity reduces the risk of developing diseases such as cancer or suffering from reproductive disorders. In turn, the genotoxic risk depends on the intrinsic capability of the individual to metabolize and eliminate the xenobiotic from the organism. This study aimed to determine if two polymorphisms of paraoxonase-1 (PON1), which is involved in the metabolism of several organophosphate (OP) pesticides, are predictors of susceptibility to DNA damage in agricultural workers and inhabitants of rural areas chronically exposed to pesticides. A cross-sectional study was made considering three groups: agricultural workers (occupational exposure, OE, n = 85), rural inhabitants (environmental exposure, EE, n = 60), and an unexposed group conformed by people living far from agricultural areas (U, n = 33). The level of individual DNA damage was measured using the comet assay, and genotyping was done to determine the PON1 Q192R and L55M polymorphisms. Acetylcholinesterase and butyrilcholinesterase activities were also measured to determine exposure to OP. Individuals belonging to EE and OE groups displayed higher levels of DNA damage compared with U group (p < .001). OP exposure was the main predictor of genotoxicity (β = 16.19; 95% CI: 1.85, 30.52), instead of PON1 polymorphisms (β = -12.20; 95% CI: -27.87, 3.48). These results confirm the genotoxic effects of pesticide exposure and suggest that the catalytic efficiency of PON1 to metabolize OP pesticides becomes negligible in individuals with a history of long-term environmental or occupational exposure to these substances.

Current perspective on veterinary drug and chemical residues in food of animal origin

The marked increase in the demand for animal protein of high quality necessitates protecting animals from infectious diseases. This requires increasing the use of veterinary therapeutics. The overuse and misuse of veterinary products can cause a risk to human health either as short-term or long-term health problems. However, the biggest problem is the emergence of resistant strains of bacteria or parasites. This is in addition to economic losses due to the discarding of polluted milk or condemnation of affected carcasses. This paper discusses three key points: possible sources of drug and chemical residues, human health problems, and the possible method of control and prevention of veterinary drug residues in animal products.

Chromatographic techniques for the analysis of organophosphate pesticides with their extraction approach: a review (2015-2020)

In agriculture, a wide range of OPPs has been employed to boost crop yield, quality, and storage life. However, due to the ever-increasing population and rapid urbanization, pesticide use has surged in recent years. These compounds are exceedingly poisonous to humans, and despite the fact that specific legislation prohibits their use, the frequency of toxic and/or fatal incidents, as well as current statistics, suggest that they are currently accessible. As a result, determining the exposure to these substances as well as their detection (and that of their metabolites) in different types of exposed samples has become a hot issue in terms of quality and safety concerns. However, developing tools for the evaluation of these substances is a critical challenge for laboratories. Various chromatographic-based methods reported in the period of 2015-2020 have been developed, which are summarized and critically reviewed in this article, including the extraction of the target OPPs from different kinds of matrices. A comparison among the extraction and analysis techniques has been made in the current review article.

Parenting, Pesticides and Adolescent Psychological Adjustment: A Brief Report

Pesticides used to control insects, such as pyrethroids, are neurotoxicants, yet adolescent researchers often overlook their potential role in adolescent psychological adjustment. This brief report is guided by bioecological theory and considers the possible independent and interactive effects of environmental pyrethroid pesticide exposure for adolescent depressive symptoms. Self-reported adolescent appraisals of the parent-child relationship and depressive symptoms were obtained from a convenience sample of impoverished, predominantly Latino urban youth (n = 44). Exposure to environmental pyrethroids was obtained from wipe samples using a standardized protocol. Parent-adolescent conflict was higher in households with bifenthrin than those without, and adolescent depressive symptoms were elevated in homes where cypermethrin was detected. In addition, the presence of bifenthrin in the home attenuated the protective effects of parental involvement on adolescent depressive symptoms. The current results suggest that adolescent mental health researchers must consider the synergistic combinations of adolescents' environments' physical and social features. Given the endemic presence of pesticides and their neurotoxic function, pesticide exposure may demand specific attention.

Bioremediation role of Spirulina platensis against deltamethrin-mediated toxicity and its chemical residues in chicken meat

Deltamethrin (DM) is a synthetic pyrethroid insecticide commonly used in veterinary and agriculture. However, both animal and human exposure are associated with hepatorenal toxicity. Our experimental goal was to assess the protective effects of Spirulina platensis (SP) against DM-induced hepatorenal injury, growth performance, meat chemical composition, and its residues in meat, liver, and skin of broiler chickens. Sixty 1-day-old Cobb broiler chicks were assigned to 4 experimental groups; each was divided into 3 replicates with five chicks each; the 1st group received basal diet alone (control), 2nd group supplemented with SP 20 g/kg diet, 3rd group supplemented with DM 300 mg/kg diet, and 4th group supplemented with DM and SP diet. All groups have received the treatment for 35 days. DM, decreased body weight, weight gain, and increased feed conversion rate. DM showed a significant increase in ALT, AST, urea, creatinine, and MDA and a significant decrease in SOD, and GSH levels. Also, SP significantly reduced DM levels in meat, skin, and liver with a reduction 63.01, 63.00, and 62.90 %, respectively. The DM intoxicated group showed a significant decrease in protein and a marked increase in fat, cholesterol, and triglycerides when compared to the control group. Histopathological changes were also recorded. Dietary SP improved these parameters. Dietary inclusion of SP can be recommended due to the protective effects on DM-induced toxicity in broiler chickens.

Chronic exposure to low concentrations of chlorpyrifos affects normal cyclicity and histology of the uterus in female rats

Chlorpyrifos (CPF), the most used insecticide in Argentina, can act as an endocrine disruptor at low doses. We previously demonstrated that chronic exposure to CPF induces hormonal imbalance in vivo. The aim of this work was to study the effects of low concentrations of CPF (0.01 and 1 mg/kg/day) on the reproductive system of virgin adult rats. In the ovary, we studied the effects of CPF on steroidogenesis by determining steroid hormone content by RIA and CYP11 and CYP19 enzyme expression by qRT-PCR. The estrous cycle was evaluated by microscopic observation of vaginal smear, as well as by changes in uterine histology. In endometrium, we determined the fractal dimension and expression of PCNA, ERα and PR by IHC. Our results showed that chronic exposure to CPF affects ovarian steroid synthesis, causing alterations in the normal cyclicity of animals. In addition, CPF induced proliferative changes in the uterus, suggesting that it could affect reproduction or act as a risk factor in the development of uterine proliferative pathologies.

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.

Wide-scope multi-residue analysis of pesticides in beef by ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry

Increasing pesticide contamination in foods of animal origin has made the wide-scope multi-residue analysis of pesticides an international concern. In this study, a sensitive and reliable multi-residue pesticide analysis method for beef was developed with the use of 129 pesticides to demonstrate the full scope of the method. The pesticides were extracted and purified using a modified QuEChERS technique and analysed using ultra-high-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry. An orthogonal array design was employed for optimisation of the method, significantly scientising and simplifying the process. Method validation revealed satisfactory sensitivity with limits of quantification values ranging from 0.003 to 11.37 µg∙kg^-1. Matrix effects ranged from 83.85% to 120.66%. Recovery at three spiking levels (20, 50, and 100 µg∙kg^-1) were 70.51-128.12% and the intra-day and inter-day precisions were less than 20%, indicating good accuracy and precision.

Screening of lactic acid bacteria for their capacity to bind cypermethrin in vitro and the binding characteristics and its application

In this study, the cypermethrin binding characteristics of lactic acid bacteria were investigated for the first time. Two strains, Lactobacillus plantarum RS60 and Pediococcus acidilactici D15, possessed the highest cypermethrin removal capacity and good tolerance to simulated digestive juices. They were employed for further studies on cypermethrin binding characteristics. 55.06% and 56.46% of cypermethrin were removed within 0.25 h by strains RS60 and D15, respectively. The effect of pH on binding capacity was negligible. Heat treatment enhanced cypermethrin binding rate. Moreover, inactive cells were capable of removing cypermethrin from fruit and vegetable juices, with over 60% cypermethrin reduction within 2 h. No adverse effect was found on the quality of juice during the biosorption process. Besides, these two strains also could bind other several pyrethroids and 3-phenoxybenzoic acid. These findings indicated that L. plantarum RS60 and P. acidilactici D15 may be useful to reduce cypermethrin in contaminated foods.

Effect of cypermethrin on the postnatal development of the medulla oblongata and the possible protective role of melatonin in albino rats

Previous studies have shown that cypermethrin (CYP), a broad spectrum pesticide has a teratogenic effect on rat offspring born to an exposed dam with no information on its effect on the development of the brain. To the best of our knowledge, this research is the first attempt to study the postnatal development medulla oblongata of rat offspring exposed to CYP during the perinatal period and the possible neuroprotective role of melatonin. The offspring of treated female rats were organized into control, melatonin (1 mg/kg/day orally); CYP (12 mg/kg/day orally); and CYP/melatonin groups. The mothers received treatments from day 6 of gestation until day 21 after birth. At Postnatal days 7 and 21, the animals were sacrificed and their medulla oblongata was removed and subjected to histological, immunohistochemical, and electron microscopic studies. CYP induced neuronal degeneration by chromatolysis and pyknosis. Nuclear changes, cytoplasmic vacuolation, damage mitochondria, and breakdown of RER were also detected. Reduction of microtubule-associated protein-2 (MAP-2), myelin basic protein (MBP), and oligodendrocyte transcription factor expressions and increment of glial fibrillary acidic protein expression in the medulla oblongata of the developing rats were observed. On the other hand, melatonin led to an obvious improvement of the injured medulla oblongata tissues and ameliorating the damaging effects of CYP. In conclusion, melatonin has protected rats against CYP-induced histopathological and immunohistochemical changes. This may be due to the protection of MAP-2, conservation of MBP, an increment of oligodendrocytes, and alleviation of astrogliosis.

1,8-cineole and castor oil in sodium lauryl ether sulphate disrupt reproduction and ovarian tissue of Rhipicephalus (Boophilus) microplus

Essential and fixed oils have been researched as alternatives to chemical acaricides. The activity of volatile compounds from essential oils (1,8-cineole, citral and eugenol) at 1.0% (w/v) and fixed oil (castor oil) at 0.3% (w/v) dissolved in 2.0% (v/v) dimethyl sulfoxide (DMSO) + 0.2% (w/v) Tween 80^® was assessed against Rhipicephalus microplus using immersion tests. 1,8-cineole (29.0%) and castor oil (30.2%) had the highest reproductive inhibition rate. A second experiment was performed to verify the effect of the 1,8-cineole (10.0% w/v) and, or castor oil (0.3% w/v) on tick reproduction using different solubilizing agents. The highest reproductive inhibition was observed for the combination of 1,8-cineole/castor oil (94.1%) and 1,8-cineole in 2.0% (w/v) sodium lauryl ether sulphate (SLES) (92.8%). A third experiment showed morphological changes in R. microplus oocytes at different stages of development, as well as in pedicel cells. The most intense effects were observed when ticks were immersed in the formulation containing 1,8-cineole (10.0% w/v) and castor oil (0.3% w/v) dissolved in 2% (w/v) SLES. These findings highlight the potential of this formulation as an alternative for managing cattle ticks as their cytotoxic effects can reduce R. microplus reproductive success.

Prenatal Deltamethrin Exposure-Induced Cognitive Impairment in Offspring Is Ameliorated by Memantine Through NMDAR/BDNF Signaling in Hippocampus

Background: Pyrethroids have been widely used in residential and agricultural areas. However, little is known about the effects of prenatal exposure to deltamethrin on cognition in early development of offspring. In this study, the effects of prenatal exposure to deltamethrin on learning and memory abilities, N-methyl-D-aspartate receptor (NMDAR) subunits, brain derived neurotrophic factor (BDNF), Tyrosine kinase B (TrkB) receptor, and phosphorylated cAMP response element binding protein (pCREB) in the hippocampus of offspring rats were investigated.

Experimental Approaches: Groups each of six female SD rats, as F0-generation, were administered with deltamethrin (0, 0.54, 1.35, and 2.7, 9 mg/kg), or memantine (10 mg/kg), or co-administered with deltamethrin (9 mg/kg) and memantine (10 mg/kg) daily by gavage during pregnancy. The learning and memory ability was evaluated using Morris water maze (MWM) task on postnatal day 21. The expression of NMDAR (GluN1, GluN2A, and GluN2B), BDNF, pTrkB/TrkB, and pCREB/CREB in hippocampus were assessed with western blotting.

Results: Prenatal exposure to a relatively low dose of deltamethrin (2.7, 1.35, and 0.54 mg/kg) had no impact on learning and memory abilities or the expression of NMDAR, BDNF, pTrkB, and pCREB in the hippocampus of the exposed offspring. The group treated with 9 mg/kg deltamethrin showed impaired cognitive abilities and decreased expression levels of GluN1, GluN2A, GluN2B, BDNF, pCREB/CREB, and pTrkB/TrkB in the hippocampus. However, the declined cognitive ability were ameliorated by memantine treatment with increased GluN1, GluN2A, GluN2B, BDNF, pCREB/CREB, and pTrkB/TrkB expression in the hippocampus.

Conclusion and Implications: Prenatal exposure to a relatively high does of deltamethrin (9 mg/kg) alters cognition in offsprings and that this cognitive dysfunction can be ameliorated by memantine treatment. Moreover, NMDAR/BDNF signaling may be associated with the effects of prenatal exposure to deltamethrin on cognitive ability in offspring.