A study on oxidative stress biomarkers and immunomodulatory effects of pesticides in pesticide-sprayers

Physiological responses of the stingless bee Partamona helleri to oral exposure to three agrochemicals: impact on antioxidant enzymes and hemocyte count

Agrochemicals pose significant threats to the survival of bees, yet the physiological impacts of sublethal doses on stingless bees remain poorly understood. This study investigated the effects of acute oral exposure to three commercial formulations of agrochemicals [CuSO4 (leaf fertilizer), glyphosate (herbicide), and spinosad (bioinsecticide)] on antioxidant enzymes, malondialdehyde content (MDA), nitric oxide (NO) levels, and total hemocyte count (THC) in the stingless bee Partamona helleri. Foragers were exposed to lethal concentrations aimed to kill 5% (LC5) of CuSO4 (120 μg mL-1) or spinosad (0.85 μg mL-1) over a 24-h period. Glyphosate-exposed bees received the recommended label concentration (7400 μg mL-1), as they exhibited 100% survival after exposure. Ingestion of CuSO4 or glyphosate-treated diets by bees was reduced. Levels of NO and catalase (CAT) remained unaffected at 0 h or 24 h post-exposure. Superoxide dismutase (SOD) activity was higher at 0 h compared to 24 h, although insignificantly so when compared to the control. Exposure to CuSO4 reduced glutathione S-transferase (GST) activity at 0 h but increased it after 24 h, for both CuSO4 and glyphosate. MDA levels decreased after 0 h exposure to CuSO4 or spinosad but increased after 24 h exposure to all tested agrochemicals. THC showed no difference among glyphosate or spinosad compared to the control or across time. However, CuSO4 exposure significantly increased THC. These findings shed light on the physiological responses of stingless bees to agrochemicals, crucial for understanding their overall health.

The Interplay between Endogenous and Foodborne Pro-Oxidants and Antioxidants in Shaping Redox Homeostasis

Oxidative stress has been known about in biological sciences for several decades; however, the understanding of this concept has evolved greatly since its foundation. Over the past years, reactive oxygen species, once viewed as solely deleterious, have become recognized as intrinsic components of life. In contrast, antioxidants, initially believed to be cure-all remedies, have failed to prove their efficacy in clinical trials. Fortunately, research on the health-promoting properties of antioxidants has been ongoing. Subsequent years showed that the former assumption that all antioxidants acted similarly was greatly oversimplified. Redox-active compounds differ in their chemical structures, electrochemical properties, mechanisms of action, and bioavailability; therefore, their efficacy in protecting against oxidative stress also varies. In this review, we discuss the changing perception of oxidative stress and its sources, emphasizing everyday-life exposures, particularly those of dietary origin. Finally, we posit that a better understanding of the physicochemical properties and biological outcomes of antioxidants is crucial to fully utilize their beneficial impact on health.

Carbamate compounds induced toxic effects by affecting Nrf2 signaling pathways

Carbamate (CBs) is a class of insecticides which is being known as an important cause of intentional or accidental poisoning. CBs, cause carbamylation of acetylcholinesterase at neuronal synapses and neuromuscular junction. Exposure to CBs through skin contact, inhalation, or ingestion can result in significant cholinergic toxicity. This is due to the elevation of acetylcholine levels at ganglionic synapses found in both the sympathetic and parasympathetic nervous systems, as well as muscarinic receptors located in target organs of the parasympathetic nervous system, nicotinic receptors situated in skeletal muscle tissue, and the central nervous system. The association between human illnesses and environmental exposures to CBs have been extensively studied in several studies. Although CBs-triggered toxicity leads to overproduction of reactive oxygen species (ROS), the detailed association between the toxicity under CBs exposure and NFE2-related factor 2 (Nrf2) signaling pathways has not been completely clarified. In this review we aimed to summarize the latest findings on the functional interrelationship between carbamates compounds and Nrf2 signaling.

The Ameliorative Effect of Litsea martabanica (Kurz) Hook. f. Leaf Water Extract on Chlorpyrifos-Induced Toxicity in Rats and Its Antioxidant Potentials

Litsea martabanica root's antioxidant and acetylcholinesterase (AChE) activity showed promise as a pesticide detoxification agent in our previous study. In addition to its root, leaves can help alleviate pesticide exposure, although there is limited scientific evidence supporting their efficacy. However, the use of roots in several countries, such as Thailand, could contribute to environmental degradation, as highland communities traditionally used leaves instead of roots. This study aims to evaluate the antioxidant activity and anti-pesticide potential of water extract from L. martabanica leaves through in vitro and in vivo investigations. In the in vitro study, L. martabanica water extract and its fractions demonstrated antioxidant activity and induced apoptosis in hepatic satellite cells. In the in vivo study, treatment with the leaf extract led to increased AChE activity, decreased malondialdehyde (MDA) levels, increased superoxide dismutase (SOD) levels, and reduced glutathione in chlorpyrifos-exposed rats. Histopathological examination revealed that chlorpyrifos-treated rats exhibited liver cell damage, while treatment with the water extract of L. martabanica exhibited a protective effect on the liver. In conclusion, L. martabanica water extract exhibited antioxidant activity, enhanced AChE activity, and improved histopathological abnormalities in the liver.

Assessment of Malondialdehyde and Organochlorine Pesticides in Aplastic Anemia Severity Groups: Insights Into Oxidative Stress and Exposure

Background There is little evidence that pesticide exposure is the primary cause of acquired aplastic anemia (AAA), even though the prevalence of aplastic anemia (AA) is substantially higher in underdeveloped countries than in affluent countries. AA caused by pesticides has not yet been fully understood. This study aimed to examine the potential link between plasma levels of malondialdehyde (MDA) and organochlorine pesticides (OCPs) as risk factors for developing AAA in the North Indian population. Methods This case-control study was conducted at a tertiary care hospital in North India. A total of 99 participants were chosen for the study, of whom 45 were cases of AA. These cases attended the Clinical Hematology department over a period of 1.5 years (May 2018 to November 2019). Forty-five controls were age and sex-matched, apparently healthy subjects. Written informed consent was obtained from each subject before performing the study. Exclusion criteria included patients unwilling to give consent, those using medication to treat AA, those genetically predisposed to AA, those with characteristics including granuloma and dysplasia of bone marrow, any other systemic illness, and subjects with a history of smoking, drinking, or using tobacco in any form. Gas chromatography-tandem mass spectrometry (GC-MS/MS) was used to evaluate the plasma levels of organochlorines. The estimation of plasma MDA, i.e., the lipid peroxide content, was measured. Results The severity of AA is significantly associated with plasma levels of α-Hexachlorocyclohexane (p = 0.040), Heptachlor (p = 0.006), Aldrin (p < 0.001), p,p'-Dichlorodiphenyldichloroethane (p = 0.004), Endosulfan sulfate (p = 0.010), and Methoxychlor (p = 0.001). There was a statistically non-significant difference in MDA levels between cases and controls (p = 0.145); however, a statistically significant linear increase in MDA levels (p < 0.001) was observed according to the severity of AA. Conclusion Our study suggests that oxidative stress may be linked to the severity of AA. Pesticide exposure (plasma organochlorine levels) could act as a stressor, potentially initiating an alarmin response of oxidative stress in the form of lipid peroxidation (MDA) from damaged tissue, which could then lead to suppression of hematopoiesis and be a possible factor in the development of AA.

Nanostructure Lipid Carrier of Curcumin Co-Delivered with Linalool and Geraniol Monoterpenes as Acetylcholinesterase Inhibitor of Culex pipiens

(1) Background: A molecular hybridization docking approach was employed to develop and detect a new category of naturally activated compounds against Culex pipiens as acetylcholinesterase inhibitors via designing a one-pot multicomponent nano-delivery system. (2) Methods: A nanostructure lipid carrier (NLC), as a second generation of solid lipid nanoparticles, was used as a carrier to deliver the active components of curcumin (Cur), geraniol (G), and linalool (L) in one nanoformulation after studying their applicability in replacing the co-crystallized ligand imidacloprid. (3) Results: The prepared nanostructure showed spherical-shaped, polydisperse particles ranging in size from 50 nm to 300 nm, as found using a transmission electron microscope. Additionally, dynamic light scattering confirmed an average size of 169 nm and a highly stable dispersed solution, as indicated by the zeta potential (-38 mV). The prepared NLC-Cur-LG displayed competitive, high-malignancy insecticidal activity against fourth instar C. pipiens with an elevated rate of death of 0.649 µg/mL. The treatment, due to the prepared nanostructure, affects oxidative stress enzymes, e.g., hydrogen peroxide (4 ppm), superoxide dismutase (SOD) (0.03 OD/mg), and protein carbonyl (0.08 OD/mg), and there are observable upward and downward fluctuations when using different concentrations of NLC-Cur-LG, suggesting significant problems in its foreseeable insecticidal activity. The acetylcholinesterase activity was assessed by an enzyme inhibition assay, and strengthened inhibition occurred due to the encapsulated NLCs (IC50 = 1.95 µg/mL). An investigation of the gene expression by Western blotting, due to treatment with NLC-Cur-LG, revealed a severe reduction of nearly a quarter of what was seen in the untreated group. As a preliminary safety step, the nanoformulation's toxicity against normal cell lines was tested, and a reassuring result was obtained of IC50 = 158.1 µg/mL for the normal lung fibroblast cell line. (4) Conclusions: the synthesized nanoformulation, NLC-Cur-LG, is a useful insecticide in field conditions.

Investigating the effects of mesotrione/atrazine-based herbicide on honey bee foragers

A mixture of the herbicides mesotrione and atrazine (Calaris®) is a widely used herbicide in agriculture in several countries. However, the possible toxicological effects of this formulation on non-target organisms require investigation. In this study, the effects of acute oral exposure to Calaris® were evaluated in Apis mellifera foragers. The effect of seven different concentrations of Calaris® on survival and sucrose consumption was studied, while the recommended concentration for field use (FC) and its 10× dilution (0.1 FC) were used to assess overall locomotor activity, respiratory rate, flight, midgut morphology, oxidative and nitrosative stresses, and hemocyte counting. The exposure to FC or 0.1 FC decreased locomotor activity and induced damage to the midgut epithelium. Additionally, the two tested concentrations reduced superoxide dismutase activity, nitric oxide levels, and total hemocyte count. FC also increased malondialdehyde content and 0.1 FC increased respiratory rate and decreased the proportion of prohemocytes. Overall, our findings evidenced significant harmful effects on A. mellifera foragers resulting from the ingestion of the Calaris® herbicide.

Investigating the relationship between non-occupational pesticide exposure and metabolomic biomarkers

The relationship between pesticide exposures and metabolomics biomarkers is not well understood. We examined the changes in the serum metabolome (early biomarkers) and the metabolic pathways associated with various pesticide exposure scenarios (OPE: overall exposure, PEM: exposure in months, PEY: exposure in years, and PEU: reported specific pesticides use) using data from the Northern Finland Birth Cohort 1966 31-year cross-sectional examination. We utilized questionnaire data on pesticide exposures and serum samples for nuclear magnetic resonance (NMR)-based metabolomics analyses. For exposures and metabolites associations, participants size varied between 2,361 and 5,035. To investigate associations between metabolomics biomarkers and exposure to pesticide scenarios compared to those who reported no exposures multivariable regression analyses stratified by sex and adjustment with covariates (season of pesticide use, socioeconomic position (SEP), alcohol consumption, BMI, and latitude of residence) were performed. Multiple testing by Benjamini-Hochberg false discovery rate (FDR) correction applied. Pesticide exposures differed by sex, season of pesticide use, alcohol, SEP, latitude of residence. Our results showed that all pesticide exposure scenarios were negatively associated with decreased HDL concentrations across all lipoprotein subclasses in women. OPE, PEY, and PEU were associated with decreased branched-chain amino acid concentrations in men and decreased albumin concentrations in women. OPE, PEY and PEU were also associated with changes in glycolysis metabolites and ketone bodies in both sexes. Specific pesticides exposure was negatively associated with sphingolipids and inflammatory biomarkers in men. In women, OPE, PEM, and PEU were associated with decreased apolipoprotein A1 and increased apolipoprotein B/apolipoprotein A1 ratio. Our findings suggest that identification of early biomarkers of disease risk related to pesticide exposures can inform strategies to reduce exposure and investigate causal pathways. Women may be more susceptible to non-occupational pesticide exposures when compared to men, and future sex-specific studies are warranted.

Plasma Levels of Organochlorine Pesticides and Tumor Necrosis Factor-Alpha: A Potential Risk Factor for Developing Acquired Aplastic Anemia in the North Indian Population

Background Pesticide exposure might have a contributory role in the development of acquired aplastic anemia (AA). However, the precise mechanisms of pesticide-induced AA remain unknown. In this case-control study, we conducted a comparative analysis of plasma levels of organochlorine pesticides (OCP) and tumor necrosis factor-alpha (TNF-alpha) between Indian patients diagnosed with AA and an age- and sex-matched control group. Methods This is an observational case-control study conducted at a tertiary care hospital in North India. In this study, 90 subjects were included, out of which 45 were diagnosed with AA according to the criteria of the International Agranulocytosis and Aplastic Anemia Study. Cases were compared with 45 controls. A trained interviewer gave all study subjects a questionnaire to collect data regarding demographic details, exposure to pesticides, and clinical history. Physical examination and routine laboratory investigations of each subject were performed. Both cases and controls were tested for their plasma levels of organochlorines as per established protocol by gas chromatography-mass spectrometry. TNF-alpha level was measured by enzyme-linked immunosorbent assay in each subject. Results There was a significant increase in plasma levels of delta hexachlorocyclohexane (delta HCH) (p = 0.02) and heptachlor (p = 0.00) in patients with AA as compared to controls. We observed nonsignificant trends towards higher levels of beta HCH (p = 0.643), aldrin (p = 0.399), and p,p'-Dichlorodiphenyltrichloroethane (p,p'-DDT) (p = 0.453) in patients with AA when compared to the controls. There were significantly higher TNF-alpha levels (p = 0.024) in cases as compared to the controls. Conclusion Our study concludes that patients with AA exhibited higher levels of delta-HCH, heptachlor, and TNF-alpha in comparison to the control group. There is a significant positive correlation of TNF alpha with OCPs (alpha HCH, lindane, delta HCH, heptachlor, aldrin, p,p'- DDD, and methoxychlor pesticides). These organochlorines may have accumulated in the fatty tissue of bone marrow because of their lipophilic nature. This suggests that they might have served as a neoantigen to trigger an increase in TNF-alpha production, which may have led to disrupted bone marrow function through cell-mediated immunity, leading to AA.

Effect of nanostructure lipid carrier of methylene blue and monoterpenes as enzymes inhibitor for Culex pipiens

Solid lipid nanoparticles second generation, nanostructure lipid carrier (NLC), is one of the most important biodegradable nanoparticles. Nanostructure Lipid carrier (NLC) was used to encapsulate methylene blue (MB) dye, carvacrol and citronellal and their efficacy as insecticidal against Culex pipiens (Cx. pipiens) were distinguished. The prepared nanoformulation revealed very good physicochemical properties, especially the homogeneity of the particle size. Transmission electron microscope showed spherical shaped nanoparticles within range less than 200 nm. The prepared NLC-MB-MT system showed a very competitive insecticidal activity and high virulence against the mosquito larvae with higher mortality rate of LC50 of 0.141 µl/mL, in addition to high level of Oxidative stress parameters obtained through all the tested enzymes including hydrogen peroxide (4.8 ppm), protein carbonyl amount (0.12 OD/mg protein), ascorbic acid (0.15 mg) and Superoxide dismutase (SOD) showed strong increasing (0.09 OD/mg protein/min) at 6 µg/mL, respectively. Whereas paradoxical results of the oxidative stress enzymes were obtained from different concentration of nanoformulation that introduce a convenient reason for their potential insecticidal effect. The cytotoxic effect of NLC-MB-MT was evaluated using WI38 human lung cell lines, the LC50 was 6.4 mg/mL. The low cytotoxic reactivity towards the tested cell line makes the NLC-MB-MT nanoformulation has its promising insecticidal efficacy. Molecular docking study for each component were done against acetylcholine esterase protein and accepted binding modes achieved by the three compounds.

Paraoxon and glyphosate induce DNA double-strand breaks but are not type II topoisomerase poisons

We tested the hypothesis that the pesticides paraoxon and glyphosate cause DNA double-strand breaks (DSB) by poisoning the enzyme Type II topoisomerase (topo II). Peripheral lymphocytes in G0 phase, treated with the pesticides, plus or minus ICRF-187, an inhibitor of Topo II, were stimulated to proliferate; induced cytogenetic damage was measured. Micronuclei, chromatin buds, nucleoplasmic bridges, and extranuclear fragments were induced by treatments with the pesticides, irrespective of the pre-treatment with ICRF-187. These results indicate that the pesticides do not act as topo II poisons. The induction of DSB may occur by other mechanisms, such as effects on other proteins involved in recombination repair.

Organochlorine pesticides induce thyroid tumors through oxidative stress; an in vivo and in silico study

Thyroid disease is one of the most common endocrine problems around the world. Among the numerous factors, exposure to environmental elements such as pesticides is associated with an increase in the incidence of thyroid disorders. The aim of the present study was to investigate the role of organochlorine pesticides (OCPs) in induction of oxidative stress (OS) and development of thyroid tumors. This case-control study was conducted on 61 patients with papillary thyroid carcinoma (PTC), 70 patients with benign thyroid nodules (BTN), and 73 healthy individuals as control. Seven derived OCPs residues measured by gas chromatography (GC), and enzyme activities of acetylcholinesterase (AChE), superoxide dismutase3 (SOD3), catalase (CAT), glutathione peroxidase3 (GPx3) and paraoxonase1 (PON1) and also, non-enzymatic antioxidant including; malondialdehyde (MDA), total antioxidant capacity (TAC), protein carbonyl (PC), and nitric oxide (NO) biomarkers in all participants were investigated. Furthermore, all of the above enzymes were docked against measured OCPs. The results revealed that β-HCH, γ-HCH, 2,4 DDE, 4,4 DDE, 2,4-DDT, and 4,4-DDT levels along with MDA, NO, and PC levels were elevated, while AChE, SOD3, GPx3, CAT, and PON1 activities and TAC levels were decreased in the PTC and BTN groups compared with the control group. Therefore, OCPs might play a role in the development of thyroid tumors through several mechanisms including generation of OS. Importantly, in silico analysis confirmed the in vivo findings.

Organochlorine and organophosphorus pesticides may induce brain cancer through oxidative stress

In this study, oxidative stress was investigated as the possible mechanism of action of organochlorine pesticides (OCPs) and organophosphorus pesticides (OPPs) in primary brain tumors (PBT). The levels of seven OCP residues and enzymatic antioxidant biomarkers including erythrocyte acetylcholinesterase (AChE), superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), and paraoxonase-1 (PON-1) along with non-enzymatic oxidative biomarkers including malondialdehyde (MDA), protein carbonyl (PC), total antioxidant capacity (TAC), and nitric oxide (NO) were measured in blood samples of 73 patients with PBT and 104 healthy controls. A significant association was found between farming activities and PBT (55% of patients were engaged in farming activities while 45% had no farming experience). The mean levels of β-HCH, γ-HCH, 2,4 DDE, 4,4 DDE, 4,4 DDT, MDA, PC, NO, SOD, CAT, and GPx were significantly higher in PBT patients, whereas the levels of TAC, PON-1, and AChE were significantly lower in these patients. Regression analysis showed that PBT was correlated with β-HCH, γ-HCH, 2,4 DDE, 4,4 DDE, and 4,4 DDT. Based on these results, it can be concluded that OCPs and OPPs may play a role in PBT development through the formation of reactive oxygen species (ROS) and promoting oxidative stress.

Levels of anti-cyclic citrullinated peptide and antinuclear antibodies in Brazilian agricultural workers exposed to pesticides and fertilizers

Despite evidence from human and animal studies of pesticide immunotoxicity, little is known about the relationship between agricultural pesticide use and autoimmunity. The objective of the present study was to assess the association between pesticide use and anti-cyclic citrullinated peptide (anti-CCP) antibodies and antinuclear antibodies (ANA) levels. A cross-sectional study including healthy 52 agricultural and 68 non-agricultural workers aged 17-69 years was conducted in the Rio de Janeiro State, Brazil. Serum samples were tested for anti-CCP and ANA by ELISA. Data on pesticide use and covariates were obtained through structured questionnaires. We estimated associations of pesticides and other exposures with log-transformed antibody levels, adjusted for sex, age, education, crops, and fertilizers by multiple linear regression analyzes. Anti-CCP levels were associated with growing certain crops, agricultural tasks, and the use of mancozeb, paraquat, and methomyl. ANA levels were positively associated with azoxystrobin and inversely associated with linuron. These novel findings suggest associations of specific pesticides and fertilizers with anti-CCP antibodies in this healthy agricultural population, supporting the need for larger human studies of preclinical autoimmunity and pesticides.

Cognitive Impairment and Neurodegenerative Diseases Development Associated with Organophosphate Pesticides Exposure: a Review Study

A significant body of literature emphasizes the role of insecticide, particularly organophosphates (OPs), as the major environmental factor in the etiology of neurodegenerative diseases. This review aims to study the relationship between OP insecticide exposure, cognitive impairment, and neurodegenerative disease development. Human populations, especially in developing countries, are frequently exposed to OPs due to their extensive applications. The involvement of various signaling pathways in OP neurotoxicity are reported, but the OP-induced cognitive impairment and link between OP exposure and the pathophysiology of neurodegenerative diseases are not clearly understood. In the present review, we have therefore aimed to come to new conclusions which may help to find protective and preventive strategies against OP neurotoxicity and may establish a possible link between organophosphate exposure, cognitive impairment, and OP-induced neurotoxicity. Moreover, we discuss the findings obtained from animal and human research providing some support for OP-induced cognitive impairment and neurodegenerative disorders.

Breathing-Focused Yoga Intervention on Respiratory Decline in Chronically Pesticide-Exposed Farmers: A Randomized Controlled Trial

Background

Occupational exposure to pesticides has been associated with lung and cognitive function exacerbations. In the present study, we tested the effectiveness of breathing focused yoga intervention on alleviation of adverse respiratory and cognitive effects associated with chronic pesticide exposure in farmers.

Methods

We undertook a parallel, two-armed randomized controlled trial with blinded outcome assessors on a chronically pesticide-exposed farming population. The study was conducted at district Panipat, State Haryana located in the Northern part of India from November 2019 to August 2020. A total of 634 farmers were screened, and 140 farmers were randomized to breathing-focused yoga intervention (BFY, n = 70) and waitlist control arms (n = 65). BFY was delivered weekly in 45-min group sessions over 12 weeks followed by home-based practice. The primary outcome was the change in spirometry-based markers of pulmonary function from baseline expressed as raw values, Global Lung Initiative (GLI) percent predicted (pp), and GLI z-scores after 24 weeks of intervention. Secondary variables were Trail making tests (TMT A and B), Digit symbol substitution (DSST), and WHO Quality of life-BREF (WHOQOL-Bref). Analysis was by intention-to-treat. Mediation analysis was done considering oxidative stress markers as potential mediators.

Results

At the end of 6 months of intervention, the overall follow-up in the participants was 87.85% (n = 123); 90% (n = 63) in the control group, and 85.71% in the yoga group (n = 60). The mean age of the study cohort (n = 140) was 38.75 (SD = 7.50) years. Compared with the control group, at 24 weeks post-intervention, the BFY group had significantly improved status of the raw sand z scores markers of airway obstruction, after adjusting for confounders, FEV1, FVC, FEF25-75 [z score-adjusted mean differences (95% CI); 1.66 (1.10-2.21) 1.88 (1.21-2.55), and 6.85 (5.12-8.57), respectively. A fraction of FEF25-75 change (mediation percentage 23.95%) was explained by glutathione augmentation. There were also significant improvements in cognitive scores of DSST, TMT-A and TMT-B, and WHOQOL-Bref.

Conclusion

In conclusion, regular practice of BFY could improve the exacerbations in the markers of airway obstruction in chronically pesticide-exposed farmers and cognitive variables. A significant mediating effect of glutathione augmentation was also observed concerning the effect of the intervention on FEF25-75. These findings provide an important piece of beneficial evidence of the breathing-based yoga intervention that needs validation across different farming ethnicities.Clinical Trial Registration:www.ClinicalTrials.gov, identifier: CTRI/2019/11/021989.

Influence of GSTM1, T1 genes polymorphisms on oxidative stress and liver enzymes in rural and urban pesticides-exposed workers

Several studies discussed the relationship between the toxicity of organophosphates (OPs) and carbamates pesticides and oxidative stress which affects human health. This study aimed to evaluate the effects of pesticides on the induction of oxidative stress and hepatotoxicity. It was also focused on glutathione-S-transferase gene polymorphism in the modulation of these effects. In addition, the role of the educational level of exposed workers was studied. Acetylcholinesterase (AChE), butyrylcholinesterase (BuChE), liver enzymes, malondialdehyde (MDA), reduced glutathione (GSH), superoxide dismutase (SOD), and glutathione S transferase (GST) were estimated at 100 pesticide-exposed workers (50 urban researchers (UE) and 50 rural sprayers (RE)), and 100 matched controls (50 urban controls (UC)and 50 rural controls (RC)). AChE and BuChE were decreased in RE and UE compared to RC. Aspartate aminotransferase (AST) and alkaline phosphatase (ALP) activity were elevated in UE and UC compared to the RE and RC. Alanine aminotransferase (ALT) was elevated in UE compared to RE. MDA in RE and UE showed elevation compared to RC. There was a significant reduction in the levels of GSH, GST, and GPx in UE compared to RE and RC. The most sensitive pesticide-induced hepatotoxicity group were exposed workers with the GSTT1 genotype. Within these workers, ALT and ALP were significantly correlated with MDA and inversely correlated with AChE and BuChE, while AST was inversely correlated with AChE and BuChE only in UE. Conclusion: GST gene polymorphisms appeared to have a significant role in workers' susceptibility to hepatotoxic effects due to occupational exposure to pesticides; GSTT1 was the most sensitive genotype.

Pesticide exposure and genotoxic effects as measured by DNA damage and human monitoring biomarkers

Occupational pesticides exposure rises health concern due to genotoxicity and accumulation of pesticides in human biological matrices. Continuous and sublethal exposure to pesticides had been associated with oxidative stress, mutagenic and cell death. Exposure to pesticides exhibits increased level of DNA damage even if no detectable amounts of pesticides are seen in biological matrices by binding specific areas in the DNA. This interferes normal body systems and mutation in gene encoding specific activities which may lead to a wide range of cancer. Presence of pesticides compounds in human biological matrices had been evident from various studies. However, detection methods are complex and inconsistent, making it difficult to compare and generalize findings. This article provides insight into genotoxic effects, presence of pesticides and their metabolites in human biological matrices and the resultant health effects as measured by DNA damage, acetylcholinesterase (AChE) activity inhibition and other biomarkers of pesticides exposure.

Interaction of plastic particles with heavy metals and the resulting toxicological impacts: a review

Interactions of plastic particles with different organic/inorganic pollutants including heavy metals impact their ecotoxicological potential, and proper understanding in this regard is important for their ecological risk assessment. However, many studies have reported the interactions between micro-/nanoplastics (MNPs) and heavy metals (HMs), but the most prevalent interactive forces and factors monitoring their interactions are still not clear. So, the present review represents the mechanisms of interactions with special emphasis on major interactive forces and biophysicochemical and environmental factors influencing trace element's adsorption onto the surface of MNPs. Electrostatic interaction and pore-filling mechanism can best explain the HMs adsorption to MNPs. A number of biophysicochemical factors (such as biofilm, size, crystallinity, and surface charge) and environmental factors (such as pH, salt, and temperature) act together for mediating interactions and ecotoxicities of MNPs and HMs in the real environment. From a toxicological point of view, the synergistic mode of action may be more active in animals, whereas the antagonistic activity may be prevalent in plants. Besides polymer density, biofilm formation and agglomeration property of MNPs can control the vertical distribution of MNPs along the water column. Finally, the ecotoxicological potential of MNPs in the natural environment can be considered as a function of spatiotemporal variation in abiotic (including MNPs and heavy metals) and biotic components. This review will be helpful in the detail understanding of ecotoxicological risk assessment of MNPs in relation to their interaction with heavy metals.

Non-occupational exposure to pesticides and health markers in general population in Northern Finland: Differences between sexes

BACKGROUND

Occupational exposure to pesticides has been reported among general population worldwide. However, little is known about the associations between non-occupational exposure to pesticides, and biological markers of health and their response by sex.

OBJECTIVES

We aimed to assess the associations between non-occupational overall pesticide exposure, length of exposure and specific pesticides reported with 35 biological markers of health representing cardiometabolic, haematological, lung function, sex hormones, liver and kidney function profiles, and vitamin D in Finnish cohort.

METHODS

31-year cross-sectional examination of the Northern Finland Birth Cohort 1966 provided blood samples for biomarker measurements in 1997-1998. Number of subjects varied between 2361 and 5037 for given exposures and certain outcome associations. Multivariable regression analyses were performed to examine associations between overall pesticide exposure (OPE), length of pesticide exposure in months (PEM), in years (PEY), and specific pesticides use (PEU) or not with cardiometabolic [SBP, DBP, TC, LDL, HDL, triglycerides, fasting glucose, insulin, HOMA-IR, HOMA-B, HOMA-S, hs-CRP], hematological [WBC, RBC, Hb, HCT, MCV, MCH, MCHC, platelets], lung function (FVC, FEV1), sex hormones [luteinizing hormone (LH), testosterone (TT), sex-hormone binding globulin (SHBG)], liver and kidney function profiles [total protein, albumin, globulin, ALP, ALT, GGT, urea, creatinine], and vitamin D adjusting for sex, BMI, socioeconomic position (SEP) and season of pesticide use.

RESULTS

This cohort study on up to 5037 adults with non-occupational OPE, PEM, PEY and PEU differed by sex and SEP. In regression analyses, all the exposures were positively associated with total cholesterol and low-density lipoprotein cholesterol, and PEU was negatively associated with high-density lipoprotein cholesterol in females. OPE and PEM were positively associated with haematocrit in females and PEU with platelets in males. PEU was negatively associated with mean corpuscular haemoglobin. OPE and PEM were positively associated with LH in males. OPE was negatively associated with total protein and albumin in males.

DISCUSSION

In Finnish young adults, non-occupational overall pesticide exposure, length of exposure and specific pesticides were associated with multiple biological markers of health. The biological markers seem to be indicative of adverse effects of pesticides and warrant for further studies to replicate the findings and determine the underlying mechanisms.

Endpoints as human biomarkers in exposure assessment of triazoles fungicides

Potential endpoint biomarkers were evaluated in the assessment of exposure to triazoles, in the southern region of Minas Gerais, Brazil. Volunteers were divided into three groups: occupationally exposed and rural residents (n = 21), non-occupationally exposed and rural residents (n = 35) and non-occupationally exposed and urban residents (n = 30). Of all endpoints evaluated, plasma concentration of androstenedione (p < 0.001) and glycine-conjugated bile acids presented statistical differences in the three studied groups (p < 0.05). However, our findings concerning oxidative stress and testosterone levels, plus that related to unconjugated and taurine conjugated bile acids, suggested that more studies are necessary to evaluate their potential as biomarkers for triazole exposure, as statistical significance was not attained between the groups. Our human population data contributes to the development of triazole exposure risk assessment with respect to these potential effect biomarkers, in potentially vulnerable groups and individuals.

Exposure to pesticides and oxidative stress in Brazilian agricultural communities

BACKGROUND

Oxidative stress may be an important mechanism linking pesticide exposure to several diseases. We evaluated the association between pesticide exposures and oxidative stress biomarkers in Brazilian agricultural workers.

METHODS

A cross-sectional study was conducted in healthy agricultural (N = 52) and non-agricultural workers (N = 68) in a rural community in Rio de Janeiro State, Brazil. Regular pesticide use, sociodemographic, and lifestyle information was obtained by questionnaire. Oxidative stress biomarkers (N = 7) were measured in serum and plasma. We calculated percent differences and 95% confidence intervals (CI) in oxidative stress biomarkers for use of pesticides adjusted for sex, age, education, smoking, and alcohol consumption, using multiple linear regression.

RESULTS

Living close to or in the fields was associated with glutathione peroxidase activity but not with any other markers. We observed significant positive associations between 8-isoprostane levels and activities of glutathione reductase, glutathione peroxidase, and glutathione-S-transferase with reported use of certain insecticides, fungicides, and herbicides. Our results also indicate a significant and negative association between glutathione-S-transferase activity and insecticide use.

CONCLUSIONS

These findings suggest that use of pesticides may be associated with differences in oxidative stress biomarkers.

Protective Effect of Resveratrol against Hepatotoxicity of Cadmium in Male Rats: Antioxidant and Histopathological Approaches

Cadmium (Cd) is widely used in some industries and emitted from fossil fuels. It is a heavy metal with a number of side effects, including hepatotoxicity. Resveratrol (Rs) is considered an important polyphenol, which is a secondary plant metabolite and has the ability to scavenge free radicals. The study was designed to evaluate the effects of resveratrol on Cd, which induced hepatotoxicity, by the assessment of some histopathological and biochemical alterations. Forty male albino rats were divided into four groups: the 1st group was the control group, the 2nd group was treated with Cd (5 mg/kg), the 3rd group was given Rs (20 mg/kg), and the 4th group was treated with Cd in combination with Rs intraperitoneally for 30 successive days. The results indicate that Cd increased liver enzymes alanine aminotransferase and aspartate aminotransferase (AST and ALT), alkaline phosphatase ALP and gamma-glutamyl transferase (γ-GT) while reducing the total protein level; Cd increased the malondialdhyde (MDA) level while decreasing the levels of other antioxidant enzymes super oxide dismutase, catalase and glutathione peroxidase (SOD, CAT and GPx). Serious congestion and hemorrhage related to the hepatic tissues were noticed in the Cd group, and Rs plays a major role in alleviating histopathological injuries and hepatic oxidative damage. It is clear that Rs has the ability to minimize the hepatotoxicity induced by Cd in male rats.

Occupational exposure of rural workers to pesticides in a vegetable-producing region in Brazil

The health of family farmers is at risk due to occupational exposure to pesticides. The aims of the current study were to investigate the level of farmers' perception of risks associated with pesticide use and to assess their health condition based on biochemical and immunological tests. Family farmers living in a vegetable-producing region in Southern Brazil were selected to participate in the study. More than 70% of the family farmers were often exposed to more than one type of pesticides; 41.2% were intensively using several pesticides for more than one decade and 74.4% were not using personal protective equipment (PPE) at the time of pesticide handling due to low perception of the risks posed by these chemicals. Enzymatic analysis performed in participants' blood samples showed changes in catalase (CAT) and glutathione reductase (GR) activity, in lipid peroxidation (TBARS) and carbonylated protein levels, as well as in chemoattractant (IL-8) and anti-inflammatory (IL-10) interleukin expression. Low perception of health-related risks posed by pesticides can be attributed to factors such as low schooling and lack of information, which put farmers' health at risk, as evidenced by blood biochemical and immunological changes.

In Vitro Antioxidant Activity of Litsea martabanica Root Extract and Its Hepatoprotective Effect on Chlorpyrifos-Induced Toxicity in Rats

In Thailand, people in the highland communities whose occupational exposure to pesticides used the root of Litsea martabanica as a detoxifying agent. However, the scientific data to support the traditional use of this plant are insufficient. This study aimed to evaluate the antioxidant activity and anti-pesticide potential of L. martabanica root extract. Antioxidant properties were investigated by 2,2′-diphenyl-1-picrylhydrazyl (DPPH) assay, superoxide radicals scavenging assay, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay, ferric reducing antioxidant power (FRAP), and total phenolic content determination. In all assays, L. martabanica extracts and their fractions exhibited high antioxidant activities differently. The water extract is traditionally used as a detoxifying agent. Therefore, it was chosen for in vivo experiments. The rats received the extract in a way that mimics the traditional methods of tribal communities followed by chlorpyrifos for 16 days. The results showed that acetylcholinesterase activity decreases in pesticide-exposed rats. Treatment with the extract caused increasing acetylcholinesterase activity in the rats. Therefore, L. martabanica extract may potentially be used as a detoxifying agent, especially for the chlorpyrifos pesticide. The antioxidant properties of L. martabanica may provide a beneficial effect by protecting liver cells from damage caused by free radicals. Histopathology results revealed no liver cell necrosis and showed the regeneration of liver cells in the treatment group. L. martabanica extract did not cause changes in behavior, liver weight, hematological and biochemical profiles of the rats.

Multi-biomarker responses to pesticides in an agricultural population from Central Brazil

We evaluated farmworkers exposed to pesticides and individuals with no history of occupational exposure to pesticides. It was performed the comet assay to evaluate DNA damage. The immunophenotyping of TCD4⁺ lymphocyte subpopulations in peripheral blood was performed by flow cytometry. The single nucleotide polymorphisms (SNPs) in PON1, XRCC1, IL6, IL6R, TNF-α, and MIR137 genes were evaluated by real-time PCR. The exposed group was composed mostly by males (69.44%), with direct exposure to pesticides (56%) and with an average age range of 46 ± 13.89 years, being that 58.3% of farmworkers directly exposed to pesticides and reported the full use of personal protective equipment (PPE). DNA damage was greater in the exposed group (p < 0.05), reinforced by the use of PPE to denote a lower degree of DNA damage (p = 0.002). In this context, in the exposed group, we demonstrated that the use of PPE, age, gender and intoxication events were the variables that most contributed to increase DNA damage (p < 0.0001). Besides, the exposed group showed a significant increase in the subpopulations of T lymphocytes CD3⁺CD4⁺ (p < 0.05) and CD3⁺CD4⁺CD25⁺ (p < 0.0001) and a significant decrease in CD3⁺CD4⁺CD25^-FOXP3⁺ (p < 0.05). SNPs in the TNF-α (rs361525) gene presented a difference in the genotype distribution between the groups (p = 0.002). The genotype distribution of TNF-α (rs361525) was also positively correlated with the DNA damage of the exposed group (r = 0.19; p = 0.01), demonstrating a higher risk of DNA damage in the farmworkers presenting the A mutated allele. Our findings demonstrate that pesticides can exert various deleterious effects on human health by damaging the DNA as well as by influencing the immune system in the case of both direct or indirect exposure and these issues are associated to age, gender, intoxication and the nonuse of PPE.

Parkinson's disease and pesticides: Are microRNAs the missing link?

Parkinson's disease (PD) is a common neurodegenerative disorder that leads to significant morbidity and decline in the quality of life. It develops due to loss of dopaminergic neurons in the substantia nigra pars compacta, and among its pathogenic factors oxidative stress plays a critical role in disease progression. Pesticides are a broad class of chemicals widely used in agriculture and households for the protection of crops from insects and fungi. Several of them have been incriminated as risk factors for PD, but the underlying mechanisms have yet to be fully understood. MicroRNAs (miRNAs) are small, non-coding RNA molecules that play an important role in regulating mRNA translation and protein synthesis. miRNA levels have been shown to be affected in several diseases as well. Since the studies on the association between pesticides and PD have yet to reach definitive conclusions, here we review recent evidence on deregulated microRNAs upon pesticide exposure, and attempt to find an overlap between miRNAs deregulated in PD and pesticides, as a missing link between the two, and enhance future research in this direction.

Thyroid disrupting pesticides mancozeb and fipronil in mixture caused oxidative damage and genotoxicity in lymphoid organs of mice

The interference in endocrine signaling in particular of hypothyroid-pituitary-thyroid axis during embryonic/neonatal development increases the risk of long-lasting immune dysfunctioning. Anticipating that, environmentally realistic exposure of established thyroid disrupting pesticides of dithiocarbamate group mancozeb and phenylpyrazole fipronil was given to mice as individual and as mixtures (MIX-I/MIX-II) during the critical initiation phase of the immune response from postnatal day (PND) 31 till PND 60 (maturation phase). The direct exposure effect was assessed at PND 61 and the persistent effect was assessed at PND 91. Pronounced oxidative stress/genotoxicity in lymphoid organs at even low dose mixture exposure of pesticides (MIX-I/ MIX-II) continued to suppress the immune system till adulthood; might be due to the synergistic/additive action. The oxidative stress/genotoxicity effect was prevented on T4 supplementation to inhibit immunotoxicity as T4 is an immune enhancer and antioxidants. Oxidative stress/genotoxicity is suggested as a mechanism of thyroid disruption mediated immune suppression.

Over-gene expression in the apoptotic, oxidative damage and liver injure in female rats exposed to butralin

The present study is the first report for studying the toxic effects of butralin herbicide on COX2, BAX, and Bcl2 gene expression, oxidative stress, and liver damage in female rats. Female rats were received butralin in drinking water for 28 days at concentration 4.16, 312, and 3120 mg/L that corresponded to the acceptable daily intake (ADI), no observed adverse effect level (NOAEL), and 10 NOAEL, respectively. Butralin decreased body weights and increased relative liver weight of female rats exposed to high dose. It caused significant elevation in liver function enzymes, lipid peroxidation, and reactive oxygen species (ROS). Antioxidant enzymes were decreased in liver tissue by increasing the dose. Butralin induced over-expression in the apoptotic related genes including COX2, BAX, and Bcl2 and pathological alteration in the liver of female rats especially at a high dose. It can be concluded that butralin induced oxidative damage and liver injure. The mechanism of damage could be due to generate reactive oxygen species, and increase lipid peroxidation that causes over-expression in the apoptotic related genes including COX2, BAX, and Bcl2. From the Benchmark dose (BMD) approach, there is dose-dependent manner in body weight, AST, ALT, and ALP, and ALT is a very sensitive parameter.

Concentration of Selected Elements and Antioxidative Potential in a Group of Males Working in the Metal Industry: Elements And Antioxidative Potential In Men

The purpose of this study was to show that some elements have a proven antioxidative effect and are essential for the proper development and functioning of the human body. The study also assessed the concentration of selected elements and total antioxidant status (TAS) in a group of male inhabitants of Białystok, Poland, who are professionally active in the metal industry. The study group comprised 163 men aged 55–64 years. The concentration of the analyzed elements was determined using flame (Zn and Cu) and electrothermal (Se, Cd, and Pb) atomic absorption spectrometry. Spectrophotometric test kits were used to assay the TAS and glutathione reductase (GR) activity in serum. The results suggested the mean concentration of Se in serum was 54.04 ± 12.10 μg/L, which was below the reference range. A significant negative correlation was observed between the concentration of Se in the serum and Pb and Cd concentrations in the whole blood of the studied men. The concentrations of the other elements, antioxidant potential, and GR activity were within the reference range. A statistically significant positive correlation was observed between Pb and Cd, indicating combined exposure and a considerable negative correlation between lead and selenium as well as between lead and TAS. Selenium and TAS are likely to modify the adverse effects of Pb in the bodies of the studied men. The results indicate that it is necessary to constantly monitor men who are occupationally exposed to heavy metals, maintain a healthy lifestyle, and introduce effective preventive measures at a local level.

Taurine Alleviates Intestinal Injury by Mediating Tight Junction Barriers in Diquat-Challenged Piglet Models

Background: Intestinal barrier contributes as an important role in maintaining intestinal homeostasis. Oxidative stress can cause critical damages in intestinal integrity of animals. Objectives: This study was conducted to investigate the alleviated effect of taurine against small intestine (duodenum, jejunum, ileum) injury induced by oxidative stress. Methods: The piglet model of diquat-induced oxidative stress was employed. In addition, analysis of intestinal morphology, reverse transcription PCR (RT-PCR), and Western blot were used in this study. Results: Compared with the control group (CON), diquat-induced oxidative stress triggers immune response; the content of immunoglobulin M (IgM) and immunoglobulin G (IgG) was significantly changed, but 0.60% taurine supplementation could restore the level of serum immunoglobulin. Oxidative stress induces serious damage in intestinal morphology structure and tight junction barrier. Compared with the CON, the villus height of intestine was significantly decreased, the crypt depth and villus height/crypt depth (V/C) were also decreased, and 0.60% taurine supplementation could restore impaired morphology and even improve crypt depth and V/C of the jejunum and ileum. Compared with the CON, oxidative stress markedly increased the messenger RNA (mRNA) expression level of claudin-1 and occludin in the duodenum, and the value of occludin was significantly decreased in the jejunum of the diquat group (DIQ). Relative to the DIQ, 0.60% taurine supplementation increased the mRNA expression level of claudin-1, occludin, and ZO-1 in the ileum. Compared with the CON, the expression of claudin-1 protein was significantly upregulated, and occludin and ZO-1 protein were both downregulated in the small intestine of DIQ. Conclusion: Taurine exerts protective effects by regulating immune response and restores the intestinal tight junction barrier when piglets suffer from oxidative stress.

Predominant role of antioxidants in ameliorating the oxidative stress induced by pesticides

Oxidative stress has been reported as one of the adverse effects caused due to pesticides, which is the main mechanism of the toxicity in humans and animals and is a useful parameter in monitoring studies. It involves an imbalance in the equilibrium state of ROS and antioxidant defenses leading to alterations in various antioxidant enzyme levels and lipid peroxidation. The objective of the current paper is to present a review of the potential role and protective mechanism action of the antioxidant micronutrient supplementation to ameliorate the oxidative stress induced by pesticides. Studies in animal models and human were retrieved through the relevant search of the literature and categorized. Various animal studies were categorized according to the type of supplementation. Animal studies provide evidence to conclude the potential protective role of antioxidants in ameliorating the adverse effects of pesticides. Similar studies in humans are meager suggesting for further comprehensive research.

Glutathione Transferase P1-1 an Enzyme Useful in Biomedicine and as Biomarker in Clinical Practice and in Environmental Pollution

Glutathione transferase P1-1 (GSTP1-1) is expressed in some human tissues and is abundant in mammalian erythrocytes (here termed e-GST). This enzyme is able to detoxify the cell from endogenous and exogenous toxic compounds by using glutathione (GSH) or by acting as a ligandin. This review collects studies that propose GSTP1-1 as a useful biomarker in different fields of application. The most relevant studies are focused on GSTP1-1 as a biosensor to detect blood toxicity in patients affected by kidney diseases. In fact, this detoxifying enzyme is over-expressed in erythrocytes when unusual amounts of toxins are present in the body. Here we review articles concerning the level of GST in chronic kidney disease patients, in maintenance hemodialysis patients and to assess dialysis adequacy. GST is also over-expressed in autoimmune disease like scleroderma, and in kidney transplant patients and it may be used to check the efficiency of transplanted kidneys. The involvement of GSTP in the oxidative stress and in other human pathologies like cancer, liver and neurodegenerative diseases, and psychiatric disorders is also reported. Promising applications of e-GST discussed in the present review are its use for monitoring human subjects living in polluted areas and mammals for veterinary purpose.

Antioxidant, antiapoptotic, antigenotoxic, and hepatic ameliorative effects of L-carnitine and selenium on cadmium-induced hepatotoxicity and alterations in liver cell structure in male mice

L-carnitine (LC) and selenium (Se) have significant protective and antioxidant effects on several tissues. Cadmium (Cd), widely used in some industries and emitted from fossil fuels, is a heavy metal having a number of side effects, including hepatotoxicity. This study aims to assess the ameliorative function of both LC and SeCl₄ on cadmium chloride (CdCl₂)-induced liver toxicity. In total, 70 male mice included in this study were allocated to seven groups: control, CdCl₂, LC, SeCl₄, CdCl₂ plus SeCl₄, CdCl₂ plus LC, CdCl₂ plus SeCl₄ and LC groups. Hepatic aminotransferase (aspartate aminotransferase [AST] and alanine transaminase [ALT]) activity and tumor necrosis factor-alpha [TNF-α] levels, as well as the antioxidant biomarkers (superoxide dismutase [SOD], glutathione reductase [GRx], glutathione-S-transferase [GST] and catalase [CAT], were examined. Histological and transmission electron microscopic [TEM] variations in the liver were used as indicators of liver damage after the administration of CdCl₂-alone or CdCl₂ with LC, SeCl₄, or both. Genotoxic effects of CdCl₂ were also evaluated and the possible roles of SeCl₄ and/or LC on the expression of the antioxidant enzymes were studied. Results showed that administration of LC and SeCl₄ decreased CdCl₂-induced increase in ALT and AST levels and reduced oxidative stress to normal levels. In addition, LC combined with SeCl₄ had a highly synergistic effect and elevated significantly the enzymatic antioxidants and decreased lipid peroxidation levels compared with those in the CdCl₂-treated group. It is clear from the data that both LC and SeCl₄ inhibit liver injury and improve the redox state in mice.

Nonoccupational Exposure of Agricultural Area Residents to Pesticides: Pesticide Accumulation and Evaluation of Genotoxicity

Although many studies related the toxic effects of pesticides on agricultural workers, little research has been done about agricultural area residents. The purpose of this work was to monitor the presence of pesticides, as well as their genotoxic and cytotoxic potential, in humans with blood samples collected from control and intensive agricultural areas in the Thrace region. Pesticide accumulations were determined by LC-MS/MS. Cytotoxicity and genotoxicity were analyzed by comet assay, and the effect of pesticide accumulation on oxidative stress, DNA repair, and molecular chaperone response were analyzed by qRT-PCR assays in the human blood samples. The agricultural area residents had a significantly higher concentration of pesticides than those in the control area at all three sampling times, and the total pesticide amounts were 4.3 and 10 times significantly higher in blood sampled in the pesticide use period (August 2015 and 2016, respectively) than in the nonuse period (November 2015). The results showed that the pesticide level in blood during the use period led to oxidative stress, DNA damage (mean comet length and % tail DNA), and unfolded/misfolded protein response. Particularly, in pesticide use season, difference between these parameters was found statistically significant with comparison to control. Our results indicate that individuals residing around a monoculture rice farming area comprise an at-risk group as a result of increased genotoxicity evidenced in human blood. We suggest that biological monitoring efforts should be used to control nonoccupational exposures to pesticides and thus safeguard the health of agricultural area residents.

Biomarkers of oxidative stress in blood of workers exposed to non-cholinesterase inhibiting pesticides

In occupational settings workers are often exposed to pesticides at relatively high doses compared to environmental exposures. Long-term exposure to pesticides has been associated with numerous adverse health effects in epidemiological studies, and oxidative stress is often claimed as one of the underlying mechanisms. In fact, different pesticides have been reported to induce oxidative stress due to the generation of free radicals and/or alteration in antioxidant defense enzymes. The present study examined greenhouse workers regularly exposed to diverse pesticides under integrated production system, and a group of controls of the same geographic area without any chemical exposure. Two different periods of the same crop season were assessed, one of high exposure (with greater use of pesticides) and other of low exposure (in which a less use of these compounds was made). Non-specific biomarkers of oxidative stress, e.g. thiobarbituric acid reactive substances (TBARS), ferric reducing ability of serum (FRAS), total thiol groups (SHT), gamma-glutamyl transpeptidase (GGT) and paraoxonase-1 (PON1) were measured in serum samples from all study subjects, alongside erythrocyte acetylcholinesterase (AChE). Results are suggestive of a mild increase in oxidative stress associated with pesticide exposure, which was compensated by an adaptive response to raise the antioxidant defenses and thus counter the detrimental effects of sustained oxidative stress. This response led to significantly increased levels of FRAS, SHT and PON1 in greenhouse workers relative to controls. Furthermore, AChE was decreased likely as a result of oxidative stress as workers did not use organophosphate insecticides.

Hematological Abnormality, Oxidative Stress, and Genotoxicity Induction in the Greenhouse Pesticide Sprayers; Investigating the Role of NQO1 Gene Polymorphism

The widespread use of pesticides in agriculture represents a threat to the human populations exposed to them. In this cross-sectional study, the hematological and biochemical parameters, plasma cholinesterase (PChE) activity, oxidative stress, genotoxicity, and NAD(P)H: quinone oxidoreductase 1 (NQO1) C609T polymorphism were measured in 100 greenhouse workers occupationally exposed to pesticide mixture and 104 normal healthy controls. There was a decrease in erythrocytes (5.45%, p = 0.026) and hemoglobin (3.26%, p = 0.025), and an increase in mean corpuscular hemoglobin (3.54%, p = 0.013) in the exposed workers. Sprayers showed a reduction in PChE (23%) and GSH (50%) levels, and an increase in lipid peroxidation (LPO) (55%), protein carbonyl (145%), Superoxide dismutase activity (61%), and total antioxidant capacity (35%) (p < 0.001 for all parameters but LPO: p = 0.009). Genotoxicity parameters were significantly high in the exposed cases (for all parameters: p < 0.001 but tail length: p = 0.002). There was a significant correlation between oxidative stress and genotoxicity parameters, and also between these biomarkers and PChE activity. The NQO1 C609T polymorphism was not significantly associated with studied biomarkers. The findings indicate that occupational exposure to a mixture of pesticides can induce hematotoxicity, oxidative stress, and genotoxicity in greenhouse workers.

Oxidative stress and genetic damage among workers exposed primarily to organophosphate and pyrethroid pesticides

The indiscriminate use of pesticides in agriculture and public health campaigns has been associated with an increase of oxidative stress and DNA damage, resulting in health outcomes. Some defense mechanisms against free radical-induced oxidative damage include the antioxidant enzyme systems. The aim of this study was to determine the levels of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), and the relationship of antioxidant enzyme levels with DNA damage among sprayers (workers) occupationally exposed to pesticides. The determinations of MDA and antioxidant enzymes were performed spectrophotometrically. The genotoxic effects were evaluated using the comet assay. The results showed a marginally significant decrease in SOD and CAT activities in the high exposure group compared to the control group. For MDA, statistically significant differences were found among people working long term vs. those working temporarily (P = 0.02) as sprayers. In the moderate exposure group, a positive correlation was observed between MDA levels and GPx activity. In the high exposure group, a negative correlation was observed between GR and CAT activities, and between MDA levels and GPx activities. Furthermore, in the high exposure group, a positive correlation between DNA damage parameters and MDA levels was observed. The results suggest an important role of antioxidant enzymes for the protection of DNA damage caused by occupational exposure to pesticides.

Concomitant effect of low dose of lindane and intranasal lipopolysaccharide on respiratory system of mice

Lindane is very commonly used organochlorine pesticide and has been reported to cause several toxic effects including respiratory insufficiency. However, effects of low concentration of lindane alone or in combination with microbial molecules on lungs are not fully understood. To understand the effects a preliminary study was designed on Swiss albino mouse. Male mice were divided into treatment and control group (20; each). Treatment mice were given lindane in ground nut oil orally at 0.25 mg kg^-1 day^-1 for 60 days. After treatment, 10 mice were challenged with intranasal Escherichia coli lipopolysaccharide (LPS; 80 μg per mice) and remaining 10 with normal saline. The mice were euthanized 16 h post-LPS exposure. Control mice (10 each) were given normal saline or the LPS alone. Mice exposed with lindane and in combination with LPS had increase in total cell counts and leukocyte counts in broncho-alveolar lavage. Histological examination showed lung injury in the lindane-treated mice. The histopathological changes were more pronounced in lindane along with LPS-exposed mice. Lindane alone and in combination with LPS showed expression of immunopositive Toll-like receptor (TLR)-4 and tumour necrosis factor-alpha (TNF-α) positive reaction in various cells of lungs. While LPS induced acute inflammation in the lungs, combination of lindane and LPS exacerbated histological signs of the inflammation. The data indicate that lindane alone or in combination with LPS caused changes in lung morphology and altered TLR-4 and TNF-α expression which may have led to altered response to LPS challenge.

Fluazifop-p-butyl, an aryloxyphenoxypropionate herbicide, diminishes renal and hepatic functions and triggers testicular oxidative stress in orally exposed rats

Fluazifop- p-butyl (FPB) is a selective aryloxyphenoxypropionate herbicide. Its phytotoxicity mechanism involves inhibition of lipid biosynthesis, free-radical generation, and oxidative stress in vulnerable plants. This study evaluates the impact of orally administered FPB on selected tissues in non-target animal model. Twenty-four male wistar rats (160–180g) were randomized into groups (I–IV). Group-I served as control, while animals in groups II, III, and IV received FPB at 18.75, 37.5, and 75 mg/kg body weight/day p.o., respectively, for 21 days. FPB caused significant ( p < 0.05) increase in plasma biomarkers of renal and hepatic function (urea, creatinine, bilirubin, alkaline phosphatase, alanine aminotransferase, and aspartate aminotransferase) when compared to control. Significant reductions in testicular ascorbic acid, glutathione, and activities of glutathione-S transferase, superoxide dismutase, and catalase were observed in FPB-treated animals when compared to control, in a dose-dependent manner. This was accompanied by increased testicular lipid peroxidation in the treated groups. Furthermore, a significant decrease in testicular acid phosphatase and γ-glutamyl transferase activities was also observed in the FPB-treated groups in a dose-dependent manner compared to control. However, testicular lactate dehydrogenase activity was significantly increased in the FPB-treated rats when compared to control. Additionally, histopathological studies revealed severe interstitial oedema and congestion of testicular blood vessels in the FPB-treated groups. Overall, data from this study suggest that FPB induced hepatotoxicity, nephrotoxicity, and oxidative stress-mediated alteration of testicular functions in rat.

Ameliorative effect of flaxseed oil against thiacloprid-induced toxicity in rats: hematological, biochemical, and histopathological study

The present study was carried out to evaluate the hematological, biochemical, and histopathological changes due to thiacloprid toxicity, and the potential protective role of flaxseed oil in male Wistar albino rats. Subacute thiacloprid intoxication induced a significant increase in RBCs, Hb, PCV, and WBCs count, and bone marrow micronucleus (MN) formation. Moreover, there was a significant increase in serum biochemical parameters related to hepatic injury: alanine aminotransferase (ALT) and alkaline phosphatase (ALP). Serum total protein and albumin levels were significantly reduced. Thiacloprid increases tumor necrosis factor-alpha (TNF-α) and interleukine-2(IL-2). There was a significant decrease in glutathione-S-transferase, while the lipid peroxidation (MDA) and cytochrome P450 activity were significantly increased. Flaxseed oil coadministration partially retrieved the changes in all studied parameters. Thiacloprid induced histopathological liver damage, which was minimized as a result of flaxseed oil treatment. In general, it was concluded that, flaxseed oil able to protect against thiacloprid-induced hepatoxicity.

A minireview on N-acetylcysteine: An old drug with new approaches

N-acetylcysteine (NAC), a cysteine pro-drug and glutathione precursor has been used in therapeutic practices for several decades, as a mucolytic agent and for the treatment of numerous disorders including paracetamol intoxication. There is a growing interest concerning the beneficial effects of NAC against the early stages of toxicity-induced by pesticides. Nevertheless, the mechanisms underlying the therapeutic and clinical applications of NAC are not fully understood. In this review we aimed to focus on the protective effects of NAC against oxidative stress caused by pesticide in many organs. The possible mechanisms of action may be associated to its antioxidant properties. The anti-oxidative activity of NAC has been attributed to the fast reaction with free radicals as well as the restitution of reduced glutathione (GSH).

Hepatotoxicity, Nephrotoxicity and Oxidative Stress in Rat Testis Following Exposure to Haloxyfop-p-methyl Ester, an Aryloxyphenoxypropionate Herbicide

Haloxyfop-p-methyl ester (HPME) ((R)-2-{4-[3-chloro-5-(trifluoromethyl)-2-pyridyloxy]phenoxy}propionic acid), is a selective aryloxyphenoxypropionate (AOPP) herbicide. It exerts phytotoxicity through inhibition of lipid metabolism and induction of oxidative stress in susceptible plants. This study investigated the toxicological potentials of HPME in rats. Twenty-four male Wistar rats (170–210 g) were randomized into four groups (I–IV). Group I (control) received 1 mL of distilled water, while animals in Groups II, III and IV received 6.75, 13.5 and 27 mg/kg body weight HPME, respectively, for 21 days. There was a significant (p < 0.05) increase in renal and hepatic function biomarkers (urea, creatinine, total bilirubin, ALP, ALT, AST) in the plasma of treated animals compared to control. Levels of testicular antioxidants, ascorbic acid and glutathione, and activities of glutathione-S-transferase, superoxide dismutase and catalase were reduced significantly after 21 days of HPME administration in a dose-dependent manner. The testicular malondialdehyde level increased significantly in the HPME-treated rats relative to the control. A significant decrease in testicular lactate dehydrogenase, acid phosphatase and γ-glutamyl transferase was also observed in HPME-treated animals. Testicular histology revealed severe interstitial edema and sections of seminiferous tubules with necrotic and eroded germinal epithelium in the HPME-treated rats. Overall, data from this study suggest that HPME altered hepatic and renal function and induced oxidative stress and morphological changes in the testis of rats.

Toxic effects of sub-chronic exposure of male albino rats to emamectin benzoate and possible ameliorative role of Foeniculum vulgare essential oil

Emamectin benzoate (EB) is an avermectin insecticide used extensively in pest control on vegetable and field crops. Few studies have been done for evaluating adverse effects of EB. In the current study, we evaluated the toxic effects of EB on male rats and the possible ameliorative role of fennel essential oil (FEO). Thirty two male rats were randomly divided into 4 equal groups. All groups were treated orally with distilled water (control group), 0.5mlFEOkg(-1) BW (FEO group), 2.5mgEBkg(-1) BW (EB group), and 0.5mlFEOkg(-1) BW+2.5mgEBkg(-1) BW (FEO+EB group) for 28 days. The obtained results showed that EB treatment resulted in a significant decrease in body weight, body weight gain, RBC count, Hb concentration, % PCV, MCV and MCHC. Moreover, EB significantly decreased total leukocyte, lymphocyte, monocyte and platelet count but significantly increased granulocyte count. EB markedly decreased total protein, albumin, globulin, IgG and IgM concentrations with a significant increase in TNF-α secretion. EB had a negative impact on the liver as it significantly increased ALT, ALP, and MDA, while decreasing SOD activity. Regarding to the histopathological examination, EB treatment induced coagulative necrosis and blood vessels congestion of the liver in treated rats. Furthermore, it resulted in depletion and necrosis of the white pulp of the spleen in treated rats. The co-administration of FEO with EB, however, improved the majority of parameters studied, suggesting that FEO is an important substance in decreasing toxic effects of EB.