Concentrations Of Cypermethrin Research Articles

Effects of cypermethrin as a model chemical on life cycle and biochemical responses of the tropical stingless bee Meliponula bocandei Spinola, 1853

The tropical stingless bee, Meliponula bocandei Spinola, 1853 is an important pollinator in West Africa but there is no study on the effect of pesticides on this species. This study assessed the effects of cypermethrin, a common pyrethroid on survival, taste (sucrose sensitivity), and biochemical responses of M. bocandei. The biochemical markers were superoxide dismutase [SOD], catalase [CAT], glutathione S-transferase (GST), reduced glutathione [GSH]), and acetylcholinesterase [AChE]) as well as glucose, trehalose and total protein concentrations. Test temperature was optimized by acclimatizing adult worker bees collected from a pristine natural colony to different temperature regimes in the laboratory and fed with sucrose solution. The optimized temperature (22°C) for survival and sucrose consumption was adopted for the toxicity test. The 24–48 h oral lethal dose (LD50) and 24–96 h indirect contact lethal concentration (LC50) of cypermethrin on the bees was in the range of 0.66–0.76 µg/ml and 92.24–223.69 µg/ml respectively. Also, the overall PER response reduced below 50% in bees that were orally exposed to high doses of cypermethrin. There was significant decrease in glucose, trehalose, total protein and GSH concentrations in bees when compared with the control. Also, significant alterations were observed in SOD, CAT, GST and AChE activity for both oral and contact exposure pathways. In conclusion, cypermethrin modulated the activities of biomarkers of oxidative stress and altered the level of energy metabolites in the bees.

Which Is More Toxic? Evaluation of the Short-Term Toxic Effects of Chlorpyrifos and Cypermethrin on Selected Biomarkers in Common Carp (Cyprinus carpio, Linnaeus 1758).

The general aim of this study was to investigate the negative short-term effects of different concentrations of chlorpyrifos (CPF) and cypermethrin (CYP), based on the EU legislation (MAC-EQS) in common carp (Cyprinus carpio Linnaeus, 1758) under laboratory conditions and to compare their toxicity. The fish were exposed to the pesticides for 96 h and then different histological and biochemical biomarkers were investigated in the gills and liver, and bioaccumulation analyses were conducted. The chemical studies showed increased pesticide concentrations in the gills as the first site for pollutants compared to the liver at the 96th hour. In addition, the histological analyses showed severe alterations in the gills and liver after exposure to both tested pesticides. In the gills, we found mainly intense proliferative and, to a lesser extent, degenerative changes and alterations in the circulatory system, such as necrosis and vasodilation. In the liver, regressive and progressive lesions, as well as circulatory disturbances and inflammation, were observed. The regressive lesions showed a higher degree of expression compared to the other changes. Furthermore, we found altered enzymatic activities—catalase, glutathione reductase, and glutathione peroxidase—in the liver, compared to the control. Overall, both tested pesticides impacted the studied biomarkers in common carp, even at concentrations lower than those permitted by law. However, the results of the comparative analysis showed a relatively higher toxicity of CYP compared to CPF in the fish. Still, questions persist as to whether the observed changes are adaptive or entirely destructive. To avoid any danger or risk, these pesticides must be applied cautiously, especially near water bodies.

Effect of Cypermethrin 25% EC, an Endocrine Disrupting Chemical and pH on Reproductive Health of Puntius javanicus

In the present study an attempt has been made to investigate the combined effect of sub-lethal dose of Cypermethrin 25% EC and pH on histoarchitecture of gonads and GnRH hormone of Puntius javanicus. 96h LC50 value was determined by method of Karber and it was found to be 3.65 µg/L for Puntius javanicus. Adult fish were exposed to sub-lethal concentration (0.365 µg/L) of Cypermethrin 25% EC in different pH of water, i.e. pH 5, pH 6, pH 7, pH 8.5 and pH 9.5 for 15 days. Significant histopathological alterations were found in testis and ovary of the fish subjected to sub-lethal concentration of cypermethrin 25% EC. Significant decrease (p?0.001) of GnRH concentration was recorded in pesticide exposed fishes. Significantly more histopathological alterations of gonads and decrease of GnRH concentration were recorded when fish were exposed to sub-lethal concentration of cypermethrin 25% EC in pH 5, pH 6 and pH 9.5, compared to fish exposed to sub-lethal concentration of cypermethrin 25% EC in pH 7 water. A significant increase of GnRH concentration (p?0.05) was documented in fishes exposed to sub-lethal concentration of cypermethrin in pH 8.5, compared to fishes exposed to sub-lethal concentration of cypermethrin in pH 7 and the concentration is found to be almost equal to the control group (pH 7, without toxicant). At this medium histoarchitecture of testis and ovary retained almost normal histology with least alterations.

Impact of Cypermethrin 25% EC and pH on Certain Haematological Parameters of Cyprinid Fish Puntius javanicus

In present study an attempt has been made to investigate the combined impact of sub lethal toxicity of Cypermethrin 25% EC and pH on certain blood parameters of Puntius javanicus. Adult fish were exposed to sublethal concentration (0.36 µg/L) of cypermethrin 25% EC in different pH water i.e. pH 5, pH 6, pH 7, pH 8.5 and pH 9.5 for 15 days. Significant changes in red blood cell (RBCs) count, total white blood cells (WBCs), haemoglobin % (Hb%), haematocrit value, total serum protein and blood glucose level were observed in fish exposed to sub-lethal concentration of cypermethrin. Significant decrease in red blood cell (RBCs) count, haemoglobin % (Hb %), haematocrit value and total serum protein content were found in fish exposed to sub-lethal concentration of cypermethrin in pH 5, pH 6 and pH 9.5, compared to fish exposed to sub-lethal concentration of cypermethrin in pH 7. A significant increase in these parameters were documented in fish exposed to sub-lethal concentration of cypermethrin in pH 8.5, compared to fish exposed to sub-lethal concentration of cypermethrin in pH 7. On the other hand a significant increase of total white blood cells (WBCs) and blood glucose level were recorded in fish subjected to sub-lethal concentration of cypermethrin in pH 5, pH 6 and pH 9.5, compared to fish exposed to sub-lethal concentration of cypermethrin in pH 7. Values of these parameters were decreased significantly in fish exposed to sub-lethal concentration of cypermethrin in pH 8.5, compared to fish exposed to sub-lethal concentration of cypermethrin in pH 7. The values of all studied blood parameters in fish subjected to sub-lethal concentration of cypermethrin in pH 8.5 were almost found to retain the values of control group (pH 7, without toxicant).

Fate of chlorpyrifos, omethoate, cypermethrin, and deltamethrin during wheat milling and Chinese steamed bread processing.

To investigate the fractioning of chlorpyrifos, omethoate, cypermethrin, and deltamethrin during wheat milling and the fate of four pesticides during Chinese steamed bread (CSB) processing, wheat samples, which were sprayed twice with chlorpyrifos, omethoate, cypermethrin, and deltamethrin at three levels of concentrations during the grain‐filling stage, were milled, and wheat flour was processed to CSB. The residues of four pesticides in the milling products, kneaded dough, fermented dough, and CSB were determined with GC‐MS/MS. The concentrations of chlorpyrifos, omethoate, cypermethrin, and deltamethrin in bran were 1.46–1.57, 1.85–2.13, 1.27–1.86, and 1.63–2.33 times higher than those in wheat, respectively, while the residues of the four pesticides in shorts decreased approximately 27.97% to 57.02% for chlorpyrifos, 6.22% to 44.77% for cypermethrin, and 13.13% to 61.15% for deltamethrin compared with the residues in wheat (p < .05); however, omethoate levels approximately doubled in the ten‐fold treatment group in shorts compared with those in wheat (p < .05). The residues of the four pesticides in flour were significantly lower than those in wheat, ranging from 38.68% to 98.04%. Chlorpyrifos and omethoate levels showed a slight decrease during the kneading and fermentation process, and further decreases of 2.46%–29.51% for chlorpyrifos and 14.22%–71.11% for omethoate were found in CSB; however, most of the groups of cypermethrin and deltamethrin showed various degrees of increases in kneaded and fermented dough and steamed bread compared with flour. The mechanism of this increase is unknown and needs further research.

Acute and Chronic Effects of a Glyphosate and a Cypermethrin-Based Pesticide on a Non-Target Species Eucypris sp. Vavra, 1891 (Crustacea, Ostracoda)

Ostracoda species are indicators of their current and past environment (paleoenvironment). The study aims to evaluate the acute and chronic sensitivities of a freshwater ostracod species (Eucypris sp.) to agricultural pesticides (a cypermethrin-based insecticide and a glyphosate herbicide-based formulation). Lethal concentrations (LC50) of each pesticide for the species at 24 and 48 h were determined. The chronic exposure allowed assessing the effects of low concentrations of both pesticides; firstly, on the parthenogenetic reproduction of Eucypris sp., and, secondly, on its population growth. Then, individuals of Eucypris sp. were exposed to 0.536 ppb and 1.072 ppb of cypermethrin and 4.51 ppm and 9.03 ppm of glyphosate. These concentrations are respectively the 10%, and the 20% of the 48-h LC50 (median lethal concentration) of both pesticides for the species. The estimated 24-h LC50 of cypermethrin was 7.287 ppb. At 48-h, it was 5.361 ppb. For glyphosate, the 24-h LC50 was 50.521 ppm, while at 48-h it was 45.149 ppm. After 10 days of exposure to low concentrations of cypermehrin, only 30% of females reproduced parthenogenetically with 10% and 20% of LC50-48-h. For the control treatment, reproduction in 80% of females was observed. Eucypris sp. population growth after 28 days of exposure to low concentrations of cypermethrin showed significant retardation. Regarding glyphosate chronic exposure, 60%, 50%, and 90% of individuals were able to reproduce at 10% of LC50-48-h, 20% LC50-48-h, and the control treatment, respectively. The population growth was also affected by the tested low concentrations of glyphosate. The study showed high sensitivity of Eucypris sp. to cypermethrin compared to glyphosate. However, low concentrations of both pesticides affected the species at individual and population level.

EFFECT OF HOUSEHOLD PROCESSING ON REMOVAL OF MULTI-CLASSES OF PESTICIDES FROM TOMATOES

In this paper, twenty-two pesticide residues were monitored in tomatoes.72 marketed samples were extracted and purified with QuEChERS method, and analyzed with liquid and gas Chromatography. The mean recoveries ranged from 90.75%to105.31%. The relative standard deviation was 1% to 7.5%. The limits of detection and quantification ranged from 0.0004 to 0.0231 mg.kg−1 and 0.0012 to 0.0693 mg.kg−1, and good linearity was obtained. Out of total analyzed samples, 34 samples (47.22%) were contaminated with tested pesticide residues; out of which 10 samples (13.89%) exceeded the maximum residue limits. The effects of four processing techniques (washing with tap water, washing with solution of acetic acid, peeling and boiling) on the residual pattern of five insecticides (dimethoate, carbaryl, chlorpyrifos, cypermethrin and fenvalerate) and one herbicide (2,4 dichlorophenoxy acetic acid (2,4D)) were evaluated. The reaction of the pesticides depends obviously on the physico-chemical features and also on the systemic character of the pesticides. Both of the washings lowered clearly the residues for all detected pesticides with removing up to 63.08%. Peeling was found to totally remove the residues of fenvalerate, carbaryl, cypermethrin and chlorpyrifos. Results obtained from the boiling indicated that a complete removal of 2,4D and dimethoate residues was finally achieved. In addition to that, the concentrations of cypermethrin and fenvalerate increased and processing factors above 1 were observed, the results can be seen as valuable base for monitoring of pesticides in tomatoes and supply more comprehension of residue demeanor after household processing. These implementations are important to protect consumer health from the damage of pesticide residues in food.

Transcriptomic comparison of cypermethrin‐susceptible and ‐tolerant Asian longhorned ticks (Haemaphysalis longicornis Neumann)

AbstractThe Asian longhorned tick (Haemaphysalis longicornis Neumann), native to northeast Asian regions, was recently confirmed to have invaded the USA. Although H. longicornis is a medically and economically important pest because it transmits various diseases to humans and livestock, its susceptibility to pesticides has not yet been fully investigated. Moreover, minimal genetic data on H. longicornis that could assist in its control are currently available. Therefore, in this study, to investigate the physiological response of H. longicornis to cypermethrin, a field population of H. longicornis was treated with various concentrations of cypermethrin (100–500 ppm), and the transcriptomes of a cypermethrin‐susceptible group (knock‐down at 200 ppm) and cypermethrin‐tolerant group (surviving at 500 ppm) were compared. In our analysis of the genes that were differentially expressed between the two groups of ticks, several genes involved in detoxification metabolism were upregulated in the cypermethrin‐tolerant group. Expression of genes encoding CYP450, GST, and ABC transporters were substantially higher in cypermethrin‐tolerant ticks than in the cypermethrin‐susceptible group. Given that CYP450, GST, and ABC transporters contribute to Phase I, II, and III of the detoxification metabolism process, respectively, our results suggest that H. longicornis responds physiologically to cypermethrin by altering the expression of various genes involved in detoxification metabolism, which in turn increases its tolerance to the cypermethrin.

Impacts of changes in temperature and exposure time on the median lethal concentrations (LC50) of a combination of organophosphate and pyrethroid in the control of Culex quinquefasciatus, say (Diptera: Culicidae)

Climate change factors such as rainfall, heat waves, rising temperatures and flooding have positively impacted insect vector population. This scenario poses considerable demand on chemical control. This study was carried out with the specific aim to examine the influence of changes in temperature and exposure time of C. quinquefasciatus to toxicities of pyrethroid (Cypermethrin), organophosphate (2, 2- dichlorovinyl dimethyl phosphate) and their mixtures. Eggs of C. quinquefasciatus were collected at the Federal University of Technology, Akure, Nigeria, in an area far from residential and cultivated zones, with a remote chance of the mosquitoes being exposed to insecticides. The eggs were allowed to hatch into larvae/pupae in the field at 27–29 °C temperature, 70–85% RH, 14:10 (L: D) photoperiod. F3 adult generation reared were transferred to the Entomology Laboratory and exposed to different concentrations of Cypermethrin and DDVP applied singly and in mixtures at varying temperatures and exposure time with mortality recorded. The median lethal concentration (LC50) values for the insecticides were higher when the insecticides were applied singly than when applied as mixtures. Therefore, mixtures of cypermethrin and DDVP have enhanced toxicity. Again, temperature changes also affect insecticide toxicity and because climate change has a characteristic temperature variability, it poses a barrier to insecticide toxicity. Hence, it is expedient to have a climate change adaptation policy in synergy with modality of chemical applications. Further study of toxico-kinetic of the insecticides in mosquito control is also recommended.

The effect of temperature and pollution concentration on Cypermethrin removal in liquid media by using Thiobacillus sp. and Clostridium sp.

Cypermethrin is known as synthetic pyrethroid (SP) which works to interfere the nervous system with a molecular formula of C9H11C13NO3. The use of pyrethroid pesticides which tends to be high and continuous without regard to the rules of pest control can have a negative impact, that is decreasing environmental quality and decreasing biodiversity. Pollution degradation in the soil due to pesticide residues can be done biologically by doing remediation technology. One of the microorganisms that can degrade insecticide residues in the soil is bacteria. Thiobacillus sp. and Clostridium sp. are insensitive to cypermethrin which has been prove by no inhibition zone formed on a media that contained cypermethrin. Therefor this research the aim is to determine the growth response of bacterial culture using Thiobacillus sp. and Clostridium sp. as a bioremediation to remove the insecticide cypermethrin in liquid media. Optimization of environment conditions use temperature with a variation (°C) of 25-40 and concentration of cypermethrin with a variation (ppm) of 100-250 cypermethrin analysis using the Gas-Chromatography Mass Spectrometer (GC-MS). This research proves that the bacterium Thiobacillus sp. and Clostridium sp. capable of removing cypermethrin in liquid media reaching 97% occurs at optimum conditions at 30°C and optimum concentration of 100 ppm.

English

In the present investigation, a total of 30 soil samples were collected from five different sites in Makurdi metropolis to investigate the effect of cypermethrin on some soil bacteria. Physicochemical properties of the soil samples from various sites were determined using standard procedures. Some selected soil bacteria such as Escherichia coli, Klebsiella spp., Bacillus spp., Staphylococcus spp. and Proteus spp. were isolated by the use of serial dilution and pour plating method. The percentage prevalence of Isolates shows that a total of 10 bacteria were isolated with samples from high level accounting for 50% of the isolates, North bank 30% and Wurukum samples 20%. Klebsiella spp. accounted for 30% of the isolates, Escherichia coli 10%, Staphylococcus and Bacillus spp. accounted for 20%. The resistance pattern of the isolates at different concentration (1-3%) of cypermethrin showed that all the isolates could grow in the presence of cypermethrin at 1% except Bacillus spp. However at 2%, only Klebsiella spp. grew; Staphylococcus spp., Escherichia coli and Bacillus spp. were inhibited and therefore showed no growth. These findings revealed that cypermethrin had effects on the soil bacteria at higher concentration inhibiting their growth but tolerated at lower concentration. Therefore, indiscriminate use of insecticides should be avoided and more eco-friendly means of pest control should be employed to reduce the negative impact of synthetic pesticides on beneficial soil organisms. &nbsp; Key words: Cypermethrin, resistance, pesticide, biomass, eco-friendly.

Effects of dietary cypermethrin exposure on swimming performance and expression of lipid homeostatic genes in livers of juvenile Chinook salmon, Oncorhynchus tshawytscha.

The increased use of pyrethroid insecticides raises concern for exposure to non-target aquatic species, such as Chinook salmon (Oncorhynchus tshawytscha). Cypermethrin, a type II pyrethroid, is frequently detected in surface waters and sediments at concentrations that exceed levels that induce toxicity to several invertebrate and salmonid species. To better understand the effects of cypermethrin to salmonids following dietary exposure, juvenile Chinook salmon were dietarily exposed to a 0, 200, or 2000 ng/g cypermethrin diet for a duration of 7, 14, or 21 days and assessed for body burden residues, swimming performance, lipid content, and lipid homeostatic gene expression. The average cypermethrin concentrations in fish dietarily exposed to cypermethrin for 21 days were 155.4 and 952.1 ng cypermethrin/g lipid for the 200 and 2000 ng/g pellet treatments, respectively. Increased trends of fatty acid synthase (fasn, r2 = 0.10, p < 0.05) and ATP citrate lyase (acly, r2 = 0.21, p < 0.001) mRNA expression were found in the fish livers relative to increasing cypermethrin body burden residues, though no significant changes in the mRNA expression of farnesoid X receptor or liver X receptor were observed. Furthermore, Chinook salmon dietarily exposed to cypermethrin did not have a significantly altered burst swimming performance (Umax). These results support studies that have suggested Umax may not be a sensitive endpoint when assessing the effects of certain pesticide classes, such as pyrethroids, but that dysregulation of fasn and acly expression may alter lipid homeostasis and energy metabolism in the liver of fish dietarily exposed to cypermethrin.

Haematological and Histological changes in the Iridescent Shark, Pangasius hypophthalmus (Sauvage, 1878) exposed to Sub-lethal Concentrations of Cypermethrin

Study reports the effect of cypermethrin on iridescent shark, Pangasius hypophthalmus. The sublethal concentrations of cypermethrin (1/5th and 1/10th) were selected on the basis of 96 h LC50 value (27.5μg L−1). Examination of haematological parameters of the shark exposed for 28 d to cypermethrin (2.75 and 5.5μg L−1) at an interval of 7 d showed significantly lower (p < 0.01) values of RBC, Hb, PCV, MCV, MCH and MCVH, but WBC values were significantly higher (p < 0.01) as compared to control group. Histological examinations revealed severe fragmented glomerulus, infiltration of hematopoietic tissue and degeneration of epithelial cell of renal tubules of kidney. Results revealed that both the sub-lethal concentrations (2.75 and 5.5μg L−1) of cypermethrin had a significant impact on the haematology and histology of P. hypophthalmus.

REVITALIZATION OF PESTICIDE-POLLUTED AGRICULTURAL SOIL FUNCTIONS BY MICROBIOME TRANSPLANTATION

The continuous application and often the overuse of pesticides in agricultural soils influence in time soil microbiota abundance and metabolic activities, with final potential negative effects on soil functioning. Recently, bioaugmentation has emerged as an advantageous method for revitalizing agricultural soils affected by chemicals use. In this study, the hypothesis that transplantation of soil cores with optimal microbiota community structure could serve in affected soil microbiota restoration and pesticides degradation enhancement was evaluated. To assess soil core transplantation efficiency, in this study were investigated implication of soil microbiota structure and abundance in pyrethroids degradation in soil, as well pyrethroids impact on soil microbiota metabolic activity. The presence of pyrethroid pesticides as cypermethrin, deltamethrin and fenvalerate in agricultural soils from Turda was evidenced within range of 119 845 g.kg-1. They negatively impacted both soil bacterial and fungal community abundance, decreasing them with approximately 50%. The impact of transplanted soil cores on both soil microbiota abundance as well on cypermethrin, deltamethrin and fenvalerate concentration was also evidenced. A revitalization of microbiota abundance in contaminated soil was observed after transplant (increase with 1.5-fold generally). These data positively sustain that affected soil microbiota due to use of pyrethroid pesticide could be revitalized through transplant of soil cores with no contamination.

Histopathological Changes in Liver of Freshwater Fish, Channa Marulius (Ham Buch) Exposed to Sub Lethal Concentration of Cypermethrin

Histopathological Changes in Liver of Freshwater Fish, Channa Marulius (Ham Buch) Exposed to Sub Lethal Concentration of Cypermethrin

IMPACT OF THE SUBLETHAL CONCENTRATIONS OF CYPERMETHRIN TOXICITY ON NITROGEN METABOLISM IN FRESH WATER FISH HETEROPNEUSTES FOSSILIS

Cypermethrin is a synthetic pyrethroid pesticide (C H Cl NO ) that has shown effective impact of strong pesticidal 22 19 2 3 activity observed in Heteropneustes Fossils, a fresh water fish exposed to sublethal concentrations of cypermethrin in different tissues liver, gill, and muscle for 4 and 7 seven days. The enzyme activity of Glutamate Dehydrogenase (GDH) was increased all the tissues especially in liver and gill. Significant change might be attributed to tissue change under toxic stress in Heteropneustes fossils. The increased levels of Urea and Ammonia also noticed indicate remarkably the role as biomarkers of cypermethrin toxicity. And the raise in Ammonia as well as urea levels indicates the concentration and tissue dependent which in turn helps to assess the impact of synthetic pyrethroids on the fish. The changes in Ammonia and Urea levels is often be reflected in nitrogen metabolism and interdependent biochemical reactions.

Degradation of Pyrethroid Insecticide- cypermethrin (25% EC) using Soil Microorganisms and Detection of Degradation Products

Background: Cypermethrin is used extensively to kill the pests that decreases the crop yield. Excessive use of cypermethrin results in soil and water contamination, thus affecting soil microflora and the aquatic life. Thus, removal of cypermethrin is particularly important. Different physical and chemical methods are available for the cypermethrin removal but are time consuming and costly. So, microbial degradation of cypermethrin is important. The present study aimed to isolate and identify cypermethrin degrading organisms, detection of the cypermethrin degradation product by GC- MS analysis and detection of residual amount of cypermethrin from the medium.Methods: In this laboratory investigation, soil samples were collected from different farms and isolation and identification of microorganisms capable of cypermethrin degradation was performed. Further, detection of residual cypermethrin concentration, cod value and cypermethrin degradation products using GC- MS analysis was performed.Result: Cypermethrin degrading microorganisms were isolated and identified as P. aeruginosa and K. pneumoniae. These microorganisms degraded 200mg\lit cypermethrin and the cypermethrin degradation products were detected and identified by comparing with the standard database. Residual amount of cypermethrin was detected from the medium by colorimetric method. Residual cypermethrin concentration was decreased with time in the test indicating cypermethrin degradation ability of the P. aeruginosa and K. pneumoniae. Further, COD value was determined and COD value was found to be decreased in the medium in presence of P. aeruginosa and K. pneumoniae indicating cypermethrin removal.

Cypermethrin Induces the Activation of Rat Primary Microglia and Expression of Inflammatory Proteins.

Cypermethrin activates microglia, which is found to be decisive in neurodegeneration in the experimental rats. While the involvement of microglial activation in toxicant-induced neurodegeneration is reported, the effect of low concentration of cypermethrin on the expression of inflammatory proteins from the rat primary microglia is not yet properly understood. The study intended to delineate the effect of low concentration of cypermethrin on the expression and release of proteins from the microglia. Rat primary microglial cells were treated with cypermethrin to check the expression of inflammatory proteins. Cypermethrin-treated microglia conditioned media and cells were collected to measure the expression and release of inflammatory proteins. Cypermethrin augmented the protein kinase C-δ (PKC-δ), inducible nitric oxide synthase (iNOS), phosphorylated mitogen-activated protein kinase (MAPK) p38 and p42/44, matrix metalloproteinase (MMP)-3, and MMP-9 levels in the cell lysate and tumour necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) levels in the microglia conditioned media. Pre-treatment with minocycline, a microglial activation inhibitor or rottlerin, a PKC-δ inhibitor, notably reduced the release of TNF-α in the conditioned media and expression of iNOS protein in the microglia. Minocycline reduced the expression of PKC-δ, phosphorylated p38 and p42/44 MAPKs, MMP-3, and MMP-9 proteins in the microglia. While cypermethrin-treated conditioned media induced the toxicity in the rat primary neurons, minocycline or rottlerin reduced the cypermethrin treated microglia conditioned media-induced toxicity. The outcomes of the present study suggest that cypermethrin activates microglia and releases TNF-α and IL-1β as well as up-regulates the expression of PKC-δ, iNOS, phosphorylated p38 and p42/44 MAPKs, MMP-3, and MMP-9 proteins, which could contribute to neurodegeneration.

Characterization, mechanism of cypermethrin biosorption by Saccharomyces cerevisiae strains YS81 and HP and removal of cypermethrin from apple and cucumber juices by inactive cells

Cypermethrin is a common food contaminant and environmental pollutant that cause health threats to animals and humans. In this study, the characterization, mechanism, and application of cypermethrin removal by Saccharomyces cerevisiae were investigated. The binding of cypermethrin by the strains S. cerevisiae YS81 and HP was rapid and reached equilibrium at 2–8 h. The removal efficiency was dependent on incubation temperature and yeast concentration, whereas cypermethrin binding was not affected by pH. Heat and acid treatments enhanced the binding ability. Both strains survived in simulated digestion juices and removed cypermethrin effectively under simulated gastrointestinal conditions. Among the strains tested, the YS81 strain was the better candidate for cypermethrin concentration reduction. For the two S. cerevisiae strains, the biosorption kinetics and isotherm followed the pseudo-second-order model and Langmuir model well. The cell walls and the protoplasts were the main yeast cell components involved in cypermethrin binding. Fourier transformed infrared spectroscopy analysis revealed that –OH, –NH, –C–N, –COO−, and –C–O played a major role in binding cypermethrin. Inactive cells effectively removed cypermethrin from apple and cucumber juices and did not affect the physico-chemical properties. Therefore, S. cerevisiae strains YS81 and HP may be used for cypermethrin reduction in food or feed.

Environmentally relevant concentration of cypermethrin or/and sulfamethoxazole induce neurotoxicity of grass carp: Involvement of blood-brain barrier, oxidative stress and apoptosis

In water environment, the interaction between environmental pollutants is very complex, among which pesticides and antibiotics are dominant. However, most studies only focus on individual toxic effects, rather combined. In this study, the sub-chronic exposure effect of cypermethrin (CMN, 0.65 μg/L), sulfamethoxazole (SMZ, 0.30 μg/L) and their mixture on grass crap (Ctenopharyngodon idellus) was investigated. The brain tight junction, oxidative stress and apoptosis-related indices were determined after 42 days of exposure. In terms of brain function, acetyl cholinesterase (AChE) activity was significantly inhibited by CMN, SMZ and their mixtures during exposure periods. Obvious histological damage from cellular and subcellular levels were also observed, which were further confirmed by a decrease in tight junction protein levels. Malondialdehyde (MDA) and 8-hydroxy-2-deoxyguanosine (8-OHdG) contents were significantly increased by individual compounds and mixtures, in which the content of glutathione (GSH) displayed the opposite trend. In mechanism, nuclear factor (erythrocyte derived 2) like 2(Nrf2) pathway was activated, which may trigger cellular protection to cope with CMN and SMZ exposure. However, apoptosis was also detected from the level of mRNA and histochemistry. In general, these two exogenous induced similar biological responses. The neurotoxicity of CMN was strengthened by SMZ with regard to these indices in most cases and vice versa. This study will reveal the potential co-ecological risks of pesticide and antibiotic in the aquatic organism, and provide basic data for their safety and risk assessment.