Effects Of Chlorpyrifos Exposure Research Articles

Effect of chlorpyrifos-exposure on the expression levels of CYP genes in Daphnia magna and examination of a possibility that an up-regulated clan 3 CYP, CYP360A8, reacts with pesticides.

Daphnia magna is a test organism used for ecological risk assessments of pesticides, but little is known about the expression levels of cytochrome P450s (CYP)s and their changes after pesticide exposure in the less than 24-h-olds used for ecotoxicity tests. In this study, D. magna juveniles were exposed to 0.2 μg/L of chlorpyrifos under the conditions for acute immobilization test as specified by the OECD test guideline for 24 h, and then the gene expression was compared between the control and chlorpyrifos-exposure groups by RNA-sequencing analysis, with a focus on CYP genes. Among 38 CYP genes expressed in the control group, seven were significantly up-regulated while two were significantly down-regulated in the chlorpyrifos-exposure group. Although the sublethal concentration of chlorpyrifos did not change their expression levels so drastically (0.8 < fold change < 2.6), CY360A8 of D. magna (DmCYP360A8), which had been proposed to be responsible for metabolism of xenobiotics, was abundantly expressed in controls yet up-regulated by chlorpyrifos. Therefore, homology modeling of DmCYP360A8 was performed based on the amino acid sequence, and then molecular docking simulations with the insecticides that were indicated to be metabolized by CYPs in D. magna were conducted. The results indicated that DmCYP360A8 could contribute to the metabolism of diazinon and chlorfenapyr but not chlorpyrifos. These findings suggest that chlorpyrifos is probably detoxified by other CYP(s) including up-regulated and/or constitutively expressed one(s).

Exposure to Chlorpyrifos Alters Proliferation, Differentiation and Fatty Acid Uptake in 3T3-L1 Cells.

Organophosphorus pesticides (OPs) are important factors in the etiology of many diseases, including obesity and type 2 diabetes mellitus. The aim of this study was to investigate the effect of a representative of OPs, chlorpyrifos (CPF), on viability, proliferation, differentiation, and fatty acid uptake in 3T3-L1 cells. The effect of CPF exposure on preadipocyte proliferation was examined by the MTT, NR, and BrdU assays. The impact of CPF exposure on the differentiation of preadipocytes into mature adipocytes was evaluated by Oil Red O staining and RT-qPCR. The effect of CPF on free fatty acid uptake in adipocytes was assessed with the fluorescent dye BODIPY. Our experiments demonstrated that exposure to CPF decreased the viability of 3T3-L1 cells; however, it was increased when the cells were exposed to low concentrations of the pesticide. Exposure to CPF inhibited the proliferation and differentiation of 3T3-L1 preadipocytes. CPF exposure resulted in decreased lipid accumulation, accompanied by down-regulation of the two key transcription factors in adipogenesis: C/EBPα and PPARγ. Exposure to CPF increased basal free fatty acid uptake in fully differentiated adipocytes but decreased this uptake when CPF was added during the differentiation process. Increased free fatty acid accumulation in fully differentiated adipocytes may suggest that CPF leads to adipocyte hypertrophy, one of the mechanisms leading to obesity, particularly in adults. It can therefore be concluded that CPF may disturb the activity of preadipocytes and adipocytes, although the role of this pesticide in the development of obesity requires further research.

High-Fat Diet Aggravates the Disorder of Glucose Metabolism Caused by Chlorpyrifos Exposure in Experimental Rats

Epidemiological research has demonstrated that the increase in high fat consumption has promoted the morbidity of diabetes. Exposure to organophosphorus pesticides (such as chlorpyrifos) may also increase the risk of diabetes. Although chlorpyrifos is a frequently detected organophosphorus pesticide, the interaction effect between chlorpyrifos exposure and a high-fat diet on glucose metabolism is still unclear. Thus, the effects of chlorpyrifos exposure on glucose metabolism in rats eating a normal-fat diet or a high-fat diet were investigated. The results demonstrated that the glycogen content in the liver decreased and that the glucose content increased in chlorpyrifos-treated groups. Remarkably, the ATP consumption in the chlorpyrifos-treatment group was promoted in the rats eating a high-fat diet. However, chlorpyrifos treatment did not change the serum levels of insulin and glucagon. Notably, the contents of liver ALT and AST changed more significantly in the high-fat chlorpyrifos-exposed group than in the normal-fat chlorpyrifos-exposed group. Chlorpyrifos exposure caused an increase in the liver MDA level and a decrease in the enzyme activities of GSH-Px, CAT, and SOD, and the changes were more significant in the high-fat chlorpyrifos-treatment group. The results indicated that chlorpyrifos exposure led to disordered glucose metabolism in all dietary patterns as a result of antioxidant damage in the liver, in which a high-fat diet may have aggravated its toxicity.

IMPACT OF CHLORPYRIFOS ON BACILLUS CEREUS OP3 SOIL BACTERIA ISOLATED FROM RHIZOSPHERE

Chlorpyrifos is a pesticide belongs to organophosphate group and widely used in Indian agriculture. The evaluation of chlorpyrifos removal from the soil using pesticide degrading bacteria will help in the resilience of soil fertility. Bacteria capable of degrading chlorpyrifos were isolated from chlorpyrifos-treated agricultural soil. The degradation of chlorpyrifos by a potential isolate was determined using FTIR and quantified using the molecular extinction coefficient in an ELISA reader. GC-MS was used to analyze the chlorpyrifos degradation metabolites. Additionally, the effect of chlorpyrifos exposure on genomic DNA and total protein content was determined. A total of 174 bacterial colonies were isolated, of which only 40 bacterial colonies were pesticide tolerant in 100ppm chlorpyrifos. Among them, only three isolates (OP3, OP5, and OP7) demonstrated tolerance above 100ppm. Within five days of incubation, OP3 demonstrated tolerance to chlorpyrifos concentrations up to 300ppm and 47 percent of chlorpyrifos was removed. By 16S rRNA sequencing, potential OP3 isolates were identified as Bacillus cereus OP3. FTIR spectra confirmed that B. cereus degraded chlorpyrifos, with 92.4 percent of chlorpyrifos degraded. In GC-MS analysis, metabolites such as MNitroaniline and 4-Methyl-2-{(4-Nitrophenyl)Thio}Pyrimidine were detected. Chlorpyrifos overexposure alters the total protein content of exposed cells and induces DNA breaks. As a result, it is concluded that B. cereus is able to degrade chlorpyrifos and the excessive use of pesticides make some changes in the soil bacteria. Overexposure of chlorpyrifos leads to an increase in total protein content and induce DNA strands breaks in pesticide degrading Bacillus cereus.

Effects of chlorpyrifos exposure on liver inflammation and intestinal flora structure in mice.

Chlorpyrifos (CPF) is an organophosphate insecticide commonly used to treat fruit and vegetable crops. CPF can cause severe adverse effects on body organs including the liver and central nervous system. This study investigated the CPF-induced inflammation in mice and explored the role of intestinal flora changes in liver inflammation. Adult C57BL/6 male mice were exposed to a CPF of 0.01-, 0.1-, 1- and 10-mg/kg bodyweight for 12weeks. The mice in experimental group given CPF solution dissolved in corn oil vehicle by gavage, was administered by intraoral gavage for 5days per week for 12weeks. Histopathological examination and inflammatory factor detection were performed on mice liver tissue. Faeces were used for 16S ribosomal RNA high-throughput sequencing to explore the impact of CPF on intestinal flora structure and diversity. The results showed that 1- and 10-mg/kg CPF caused different degrees of liver focal inflammation. The structure of intestinal flora changed significantly in mice including the decreased beneficial bacteria (Akkermansia, Prevotella and Butyricimonas) and increased pathogenic bacteria (Helicobacter and Desulfovibrio). Meanwhile, the results of Q-RT-PCR showed that there was more total bacterial DNA in the liver tissue of the mice treated with 10-mg/kg groups. In conclusion, the imbalance of intestinal flora, the decreased abundance of beneficial bacteria and the increased abundance of pathogenic bacteria, as well as the increase of total bacterial DNA in the liver tissues, maybe associated with the liver focal inflammation induced by CPF.

The effect of chlorpyrifos exposure on carp fish at twin lakes of West Sumatra Indonesia

This study was conducted to analyze the sublethal effect of chlorpyrifos on the Feed Conversion Ratio (FCR), Sustainable Growth Rate (SGR), and carp behaviors. The concentration used 1/7 and 1/14 of the LC50 carp. The study was conducted with the number of fish per aquarium was five fishes, and the testing exposure time was 14 days. The results of the FCR and the SGR at a concentration of 1/7 and 1/14 LC50 was 0.2907 and 0.3031, and 1.551% and 1.9581%, respectively. Changes in behavior during exposure, a decline in appearance such as being alone in the corner of the aquarium, moving irregularly and stress (r = 0.75-1), lots of mucus (r = 0.800-1), anal excretion (r = 0.6-0.799), and breathe to the surface (r = 0.800-1). This situation happened because chlorpyrifos begins to affect the nervous system of carp to reduce other body functions. The FCR and SGR had a significant effect through the statistical test due to the chlorpyrifos concentration. Whereas in carp’s physiological behavior changes, there was no significant effect due to the level of concentration provided.

Protective effects of curcumin and Ganoderma lucidum on hippocampal damage caused by the organophosphate insecticide chlorpyrifos in the developing rat brain: Stereological, histopathological and immunohistochemical study

The aim of this study is to draw attention to the possible effects of chlorpyrifos exposure on the developing rat hippocampus in the prenatal period and to determine whether these effects can be reduced with various antioxidant substances.Pregnant rats were divided into 7 groups.; Chlorpyrifos (CPF), Curcumin (CUR), Ganoderma lucidum (GNL), Chlorpyrifos + Curcumin (CPF + CUR), Chlorpyrifos + Ganoderma lucidum, (CPF + GNL), SHAM and Control (C). After the experiments, brain tissues were evaluated by stereological and immunohistochemical methods.As a result of the stereological analyzes, it was determined that the number of pyramidal neurons in the hippocampus of the CPF group decreased significantly from all other groups. In contrast, the number of neurons in the CPF + CUR and CPF + GNL groups was significantly higher than the CPF group. In addition, immunohistochemical analyzes showed that the density of cells stained with glial fibrillar acidic protein (GFAP) positive in all areas in the hippocampus of the rats in the CPF group was significantly higher compared to the control group, whereas in the CPF + CUR and CPF + GNL groups were less than the CPF group. As a result, the exposure of CPF in the prenatal period caused neurotoxicity in the brain hippocampus, whereas CUR and GNL reduced this toxicity caused by CPF.

Effects of Chlorpyrifos Exposure on Acetylcholine Metabolism across a Model Blood-Brain Barrier

Organophosphate (OP) compounds, used throughout the agricultural industry as insecticides, are known to directly and irreparably alter brain function in humans. Exposure to OPs decreases acetylcholinesterase activity and leads to a buildup of acetylcholine, with chronic exposure to sub-lethal levels inducing neuropathy. This buildup of acetylcholine can be monitored through electrochemical methods to study the effects of OP toxicity. The microclinical analyzer (µCA), an in vitro microfluidic device allowing for electrochemical analysis using a screen-printed electrode, can be modified with enzymes to detect acetylcholine. Using the µCA in combination with the neurovascular unit (NVU), an organotypic model of the blood-brain barrier (BBB), can provide a better understanding of the BBB forms, functions, and responds to insults. The NVU supports all the cell types necessary for proper BBB formation (endothelial cells, astrocytes, pericytes, and neurons) and provides the flow-created shear forces for mature tight junction formation. The µCA and NVU were used study the effects of chlorpyrifos on acetylcholine concentrations present across the BBB. Understanding the effects of OP like chlorpyrifos on neurotoxicity can contributes to the assessment and treatment of chronic and acute exposure and inform policy decisions around the uses of OP pesticides in the agricultural industry.

Age- and diet-specific effects of chronic exposure to chlorpyrifos on hormones, inflammation and gut microbiota in rats

Chlorpyrifos is a pesticide frequently detected in food and has been reported to disturb endocrine and gut health, which was regulated by gut microbiota and enteroendocrine cells. In this study, newly weaned (3 week) and adult (8 week) male rats fed a normal- or high- fat diet were chronically exposed to 0.3 mg chlorpyrifos/kg bodyweight/day. The effects of chlorpyrifos exposure on serum hormone levels, proinflammatory cytokines and gut microbiota were evaluated. Chronic exposure to chlorpyrifos significantly decreased the concentrations of luteinizing hormone, follicule stimulating hormone and testosterone, which was found only in the normal-fat diet. The counteracted effect of high-fat diet was also found in gut hormones and proinflammatory cytokines. Significantly higher concentrations of glucagon-like peptide-1, pancreatic polypeptide, peptide tyrosine tyrosine (PYY), ghrelin, gastric inhibitory poly-peptide, IL-6, monocyte chemoattractant protein-1, and TNF-α were found in rats exposed to chlorpyrifos beginning at newly weaned, whereas only the PYY, ghrelin and IL-6 concentrations increased significantly in rats exposed in adulthood. Furthermore, a decrease in epinephrine induced by chlorpyrifos exposure was found in rats exposed to chlorpyrifos beginning at newly weaned, regardless of their diet. Chlorpyrifos-induced disturbances in the microbiome community structure were more apparent in rats fed a high-fat diet and exposed beginning at newly weaned. The affected bacteria included short-chain fatty acid-producing bacteria (Romboutsia, Turicibacter, Clostridium sensu stricto 1, norank_f_Coriobacteriaceae, Faecalibaculum, Parasutterella and norank_f__Erysipelotrichaceae), testosterone-related genus (Turicibacter, Brevibacterium), pathogenic bacteria (Streptococcus), and inflammation-related bacteria (unclassified_f__Ruminococcaceae, Ruminococcaceae_UCG-009, Parasutterella, Oscillibacter), which regulated the endocrine system via the hypothalamic-pituitary-adrenal axis, as well as the immune response and gut barrier. Early exposure accelerated the endocrine-disturbing effect and immune responses of chlorpyrifos, although these effects can be eased or recovered by a high-fat diet. This study helped clarify the relationship between disrupted endocrine function and gut microbiota dysbiosis induced by food contaminants such as pesticides.

Effects of chlorpyrifos on acetylcholinesterase activity in two freshwater fish species (Cnesterodon decemmaculatus and Gambusia affinis)

Chlorpyrifos (CPF) is a widely used organophosphate insecticide. The effect of chlorpyrifos exposure on acetylcholinesterase activity (AChE, biomarker of neurotoxicity) was evaluated in two freshwater fish species (Cnesterodon decemmaculatus and Gambusia affinis). The animals were exposed to sublethal concentrations (1 and 5 µg CPF × L-1) or remained in control water for 96 h. AChE activity was inhibited 48% and 69% in C. decemmaculatus and 27% and 36% in G. affinis for 1 and 5 µg CPF × L-1, respectively. In vitro assays showed no differential sensitivity of the enzyme to CPF between species. However, the IC50 for in vitro exposure to chlorpyrifos-oxon (CPF-oxon, a product of the natural oxidative desulfuration of CPF) were 10.2 nM and 54.2 nM for C. decemmaculatus and G. affinis, respectively. Therefore, a different sensitivity of the enzyme between both species could explain the dissimilar behaviour of AChE after in vivo exposure to CPF.

PON1 status does not influence cholinesterase activity in Egyptian agricultural workers exposed to chlorpyrifos

Animal studies have shown that paraoxonase 1 (PON1) genotype can influence susceptibility to the organophosphorus pesticide chlorpyrifos (CPF). However, Monte Carlo analysis suggests that PON1 genotype may not affect CPF-related toxicity at low exposure conditions in humans. The current study sought to determine the influence of PON1 genotype on the activity of blood cholinesterase as well as the effect of CPF exposure on serum PON1 in workers occupationally exposed to CPF. Saliva, blood and urine were collected from agricultural workers (n=120) from Egypt's Menoufia Governorate to determine PON1 genotype, blood cholinesterase activity, serum PON1 activity towards chlorpyrifos-oxon (CPOase) and paraoxon (POase), and urinary levels of the CPF metabolite 3,5,6-trichloro-2-pyridinol (TCPy). The PON1 55 (P≤0.05) but not the PON1 192 genotype had a significant effect on CPOase activity. However, both the PON1 55 (P≤0.05) and PON1 192 (P≤0.001) genotypes had a significant effect on POase activity. Workers had significantly inhibited AChE and BuChE after CPF application; however, neither CPOase activity nor POase activity was associated with ChE depression when adjusted for CPF exposure (as determined by urinary TCPy levels) and stratified by PON1 genotype. CPOase and POase activity were also generally unaffected by CPF exposure although there were alterations in activity within specific genotype groups. Together, these results suggest that workers retained the capacity to detoxify chlorpyrifos-oxon under the exposure conditions experienced by this study population regardless of PON1 genotype and activity and that effects of CPF exposure on PON1 activity are minimal.

Enzymatic responses of the riceland prawn, Macrobrachium lanchesteri, to chlorpyrifos exposure

Cholinesterase (ChE) was characterized in whole bodies of adult riceland prawns, Macrobrachium lanchesteri, based on substrate preference and inhibitor sensitivity. M. lanchesteri ChE activity was mainly attributable to acetylcholinesterase (AChE) since it preferentially hydrolyzed an AChE-specific substrate, acetylthiocholine iodide, over s-butyrylthiocholine iodide and was sensitive to 1,5-bis-(4-allyldimethyl-ammoniumphenyl)-pentan-3-one dibromide, a specific inhibitor for AChE. The effect of chlorpyrifos exposure on M. lanchesteri were also investigated. The 24, 48, 72 and 96 h LC50 values for chlorpyrifos were 3.37, 2.76, 2.58 and 2.53 μg L−1, respectively. Based on these values, adult M. lanchesteri were exposed to 0.5, 1.5, 2.5 and 3.5 μg chlorpyrifos L−1 for 24, 48, 72 and 96 h. Chlorpyrifos appeared to induce drastic enzymatic responses in M. lanchesteri. AChE activity was inhibited after 24 h of exposure in a dose- and time-dependent manner. The levels of lipid peroxidation increased significantly after 24 h of exposure. However, the activities of the antioxidant enzyme, catalase, and the detoxification enzyme, glutathione S-transferase, were reduced. In conclusion, M. lanchesteri is sensitive to chlorpyrifos and can serve as a bioindicator species for freshwater environmental assessment.

Effects of Chlorpyrifos Exposure on Growth and Food Utilization in Australian Catfish, Tandanus tandanus

Australian catfish, T. tandanus were exposed to a short term pulse of chlorpyrifos at 2 or 10μgL(-1) and grown in optimal conditions to investigate the effect of the pesticide on fish growth. The final weight was lower in fish exposed to chlorpyrifos (8.54±0.19 and 8.77±0.44g) respectively compared to the control fish (10.5±0.72g) while the hepatosomatic index in fish exposed to chlorpyrifos was a higher (1.86±0.10 and 2.01±0.12) than in the control fish (1.65±0.14). Both bi-weekly growth rate and brain Acetylcholinesterase (AChE) activity increased with post-exposure time.

Survival, development, and gonadal differentiation in Rana dalmatina chronically exposed to chlorpyrifos

Chlorpyrifos is an organophosphate pesticide among the most widely used in the world, which is suspected to be an endocrine-disrupting compound. To determine the capacity of chlorpyrifos to affect gonadal differentiation in Rana dalmatina, tadpoles were exposed to this pesticide during larval development until completion of metamorphosis at ecologically relevant concentrations (0.025 and 0.05 mg/L). No effects of chlorpyrifos exposure on survival, development, or metamorphosis were observed. After a 1 month metamorphosis, the gonadal phenotype was determined by gross morphology and histological examination. Morphological and histological analysis revealed normal ovaries or testes in froglets belonging to control group, whereas testes from several froglets exposed to chlorpyrifos were interspersed with testicular oocytes in histological sections. Chlorpyrifos exposure during the entire larval period did not affect sex ratio, but reduced the percentage of males with histologically normal testes. The findings suggest that chlorpyrifos exposure has significant effects on gonadal differentiation in some animals by inducing an intersex condition and alterations to testicular morphology, and that R. dalmatina is sensitive to endocrine disruption. Thereby, this study provides evidence that the ecologically relevant concentrations of chlorpyrifos, although not adversely affect the survival, development, or metamorphosis, may interfere with sex differentiation and reproductive development of R. dalmatina via endocrine-disrupting mechanisms.

Effects of chlorpyrifos exposure on kidney Notch2–Jagged1 pathway of early prenatal embryo

To evaluate the effects of this insecticide on the embryonic development of kidney and to assess the important role of Notch2-Jagged1 pathway in this duration. Chlorpyrifos (CPF) 5 mg/kg/d were administrated on gestation 7.5-11.5 day by subcutaneous injection. On gestation 16.5 day, the normal embryo kidney developed through S shape duration to the original kidney, which had the nephrons and could start to secret the urine. But for the CPF-treated mice, the embryo kidney developed much more slowly, they did not show the S shape and the nephrons. The Notch2-Jagged1 pathway should be expressed stronger in the normal embryo kidney on gestation 16.5 day, but for the CPF-treated mice we found the obvious weak pathway staining. CPF broke the Notch2-Jagged1 pathway during the embryo kidney development, and the Notch2-Jagged1 pathway plays an important role in the S shape to original kidney formation duration.

Ecotoxicological evaluation of chlorpyrifos exposure on the nematode Caenorhabditis elegans

To investigate the effects of chlorpyrifos (CP), an organophosphorus insecticide, on the soil nematode Caenorhabditis elegans, the toxicity of the insecticide on the molecular, biochemical, and physiological levels were investigated upon sublethal exposure, and an acute toxicity test was conducted using lethality as an endpoint. To assess the molecular-level effect, stress-related gene expression was investigated, and the neurotoxicity indicator, acetylcholinesterase (AChE) activity was assessed as the biochemical-level response. Growth, reproduction and development were also studied as physiological-level responses. The overall results indicate that CP exposure leads to the alteration of the expression of some stress genes, such as of heat shock protein, metallothionein, vitellogenin and C. elegans p53-like protein genes; the inhibition of AChE activity; and the retardation of development. These data suggest that the toxicity of CP on C. elegans occurred in multiple biological organizations; nevertheless this is not sufficient to conclude that there is a casual relationship between them. Thus, direct experimental demonstrations of the wider relationships between the molecular/biochemical effects of CP exposure and their consequences at higher levels of biological organization are needed to fully understand the effects of this compound on C. elegans.

Bioaccumulation of Chlorpyrifos Through an Experimental Food Chain: Study of Protein HSP70 as Biomarker of Sublethal Stress in Fish

The accumulation and transfer of the organophosphorus pesticide chlorpyrifos has been studied in an experimental aquatic two-level food chain using two species of the crustacean Artemia (A. franciscana and A. parthenogenetica) and the small fish Aphanius iberus. Artemia adults contaminated by exposure to the pesticide in water were used as live prey for Aphanius, the next trophic level. During the experimental bioaccumulation phase, fish were fed chlorpyrifos-contaminated Artemia pools with concentrations between 6.5 and 14.5 ng/g fresh weight for 32 days. Both concentrations accumulated in fish, and biomagnification factor (BMF) values showed a continuous decrease during the bioaccumulation phase, probably due to the physicochemical characteristics of the organophosphorus pesticide, to the biotransformation ability of fish and to the progressive adaptation of fish metabolism to toxic exposure. The first day that fish were fed uncontaminated preys, the pesticide accumulated via food was rapidly eliminated and was not detected. The effect of chlorpyrifos exposure through the food chain on stress protein (HSP70) synthesis was measured as a general biochemical response of stress in the fish (A. iberus). The levels of HSP70 were significantly higher in fish fed on contaminated Artemia than in the control fish fed on uncontaminated Artemia. Results showed that the HSP70 induction in fish could be associated to exposure of chlorpyrifos via food.