Mitochondrial Respiratory Dysfunction and Oxidative Stress after Chronic Malathion Exposure

Corn oil and Soybean oil effect as vehicles on behavioral and oxidative stress profiles in developmentally exposed offspring mice

Corn and soybean oils are among the most frequently used vehicles for water-insoluble compounds in toxicological studies. These two vegetable oils are nutrients and may induce some biological effects on animals that might interfere with the experimental results. However, their chronic effects on a developing brain have not been reported. This study aims to evaluate the neurobehavioral and brain biochemical effects of both oils on male and female Swiss albino mice. Pregnant female mice were exposed to 1 µl/g/d of either tap water, corn oil (CO), or soybean oil (SO) from early gestation (GD1) until weaning then offspring mice were exposed to the same treatment regimen until adulthood (PND70). Our results showed that developmental exposure to both oils induced body weight changes in offspring mice. In addition, we detected some behavioral abnormalities where both oil-treated groups showed a significant decrease in locomotor activity and greater levels of anxiety behavior. Moreover, our results suggest that continuous exposure to these oils may alter motor coordination, spatial memory and induce depression-like behavior in adult mice. These alterations were accompanied by increased malondialdehyde, superoxide dismutase, and glutathione peroxidase activities in specific brain regions. Together, these data suggest that exposure to CO and SO as vehicles in developmental studies may interfere with the behavioral response and brain redox homeostasis in offspring mice.

Sex-specific neurobehavioral and biochemical effects of developmental exposure to Malathion in offspring mice

Malathion is an organophosphate pesticide (OP) commonly used in agriculture, industry, and veterinary medicine. Sex is a crucial factor in responding to neurotoxicants, yet the sex-specific effects of OP exposure, particularly neurological impairments following chronic low-level exposure remains limited. Our study aims to evaluate the neurobehavioral and biochemical effects of developmental exposure to Malathion across sexes. Pregnant mice were exposed to a low oral dose of Malathion from gestation up to the weaning of the pups, which were individually gavaged with a similar dose regimen until postnatal day 70. Our results show that Malathion decreased body weight and food intake, reduced locomotor activity and recognition memory. Motor coordination and special memory were only altered in females, whereas we found a male-specific effect of Malathion on social behavior and marble burying. These alterations were accompanied by increased malondialdehyde (MDA), decreased brain acetylcholinesterase activity (AChE), and disrupted brain redox homeostasis. Our findings about the effects of Malathion exposure across sexes may, in part, contribute to understanding the dimorphic susceptibilities observed in neurological disorders.

Mitochondrial coding genes mediate insecticide tolerance in the oriental fruit fly, Bactrocera dorsalis (Hendel)

The oriental fruit fly, Bactrocera dorsalis (Hendel), an invasive insect pest infesting fruits and vegetables, possesses a remarkable capacity for environmental adaptation. The investigation of behind mechanisms of the stress adaptability in B. dorsalis holds significantly practical relevance. Previous studies on the molecular mechanism underlying stress resistance in B. dorsalis have predominantly focused on nuclear-coding genes, with limited exploration on organelle-coding genes. In this study, we assessed alterations in the mitochondrial physiological parameters of B. dorsalis under exposure to malathion, avermectin, and beta-cypermethrin at LD50 dosages. The results showed that all three insecticides were capable of reducing mitochondrial complex IV activity and ATP content. Expression patterns of mitochondrial coding genes across different developmental stages, tissues and insecticide exposures were analyzed by RT-qPCR. The results revealed that these mitochondrial coding genes were expressed in various tissues and at different developmental stages. Particularly noteworthy, atp6, cox2, and cytb exhibited substantial up-regulation in response to malathion and avermectin treatment. Furthermore, RNAi-mediated knockdown of atp6 and cox2 resulted in the increased toxicity of malathion and avermectin against B. dorsalis, and cox2 silencing was also associated with the decreased complex IV activity. These findings suggest that atp6 and cox2 most likely play pivotal roles in mediating tolerance or resistance to malathion and avermectin in B. dorsalis. Our results provide novel insights into the role of mitochondrial coding genes in conferring tolerance to insecticides in B. dorsalis, with practical implications for controlling this pest in the field.

Bioenergetic function is decreased in peripheral blood mononuclear cells of veterans with Gulf War Illness

Gulf War Illness (GWI) is a major health problem for approximately 250,000 Gulf War (GW) veterans, but the etiology of GWI is unclear. We hypothesized that mitochondrial dysfunction is an important contributor to GWI, based on the similarity of some GWI symptoms to those occurring in some mitochondrial diseases; the plausibility that certain pollutants to which GW veterans were exposed affect mitochondria; mitochondrial effects observed in studies in laboratory models of GWI; and previous evidence of mitochondrial outcomes in studies in GW veterans. A primary role of mitochondria is generation of energy via oxidative phosphorylation. However, direct assessment of mitochondrial respiration, reflecting oxidative phosphorylation, has not been carried out in veterans with GWI. In this case-control observational study, we tested multiple measures of mitochondrial function and integrity in a cohort of 114 GW veterans, 80 with and 34 without GWI as assessed by the Kansas definition. In circulating white blood cells, we analyzed multiple measures of mitochondrial respiration and extracellular acidification, a proxy for non-aerobic energy generation; mitochondrial DNA (mtDNA) copy number; mtDNA damage; and nuclear DNA damage. We also collected detailed survey data on demographics; deployment; self-reported exposure to pesticides, pyridostigmine bromide, and chemical and biological warfare agents; and current biometrics, health and activity levels. We observed a 9% increase in mtDNA content in blood in veterans with GWI, but did not detect differences in DNA damage. Basal and ATP-linked oxygen consumption were respectively 42% and 47% higher in veterans without GWI, after adjustment for mtDNA amount. We did not find evidence for a compensatory increase in anaerobic energy generation: extracellular acidification was also lower in GWI (12% lower at baseline). A subset of 27 and 26 veterans returned for second and third visits, allowing us to measure stability of mitochondrial parameters over time. mtDNA CN, mtDNA damage, ATP-linked OCR, and spare respiratory capacity were moderately replicable over time, with intraclass correlation coefficients of 0.43, 0.44, 0.50, and 0.57, respectively. Other measures showed higher visit-to-visit variability. Many measurements showed lower replicability over time among veterans with GWI compared to veterans without GWI. Finally, we found a strong association between recalled exposure to pesticides, pyridostigmine bromide, and chemical and biological warfare agents and GWI (p < 0.01, p < 0.01, and p < 0.0001, respectively). Our results demonstrate decreased mitochondrial respiratory function as well as decreased glycolytic activity, both of which are consistent with decreased energy availability, in peripheral blood mononuclear cells in veterans with GWI.

Adverse effect propensity: A new feature of Gulf War illness predicted by environmental exposures

A third of 1990-1 Gulf-deployed personnel developed drug/chemical-induced multisymptom illness, "Gulf War illness" (GWI). Veterans with GWI (VGWI) report increased drug/exposure adverse effects (AEs). Using previously collected data from a case-control study, we evaluated whether the fraction of exposures that engendered AEs ("AE Propensity") is increased in VGWI (it was); whether AE Propensity is related to self-rated "chemical sensitivity" (it did); and whether specific exposures "predicted" AE Propensity (they did). Pesticides and radiation exposure were significant predictors, with copper significantly "protective"-in the total sample (adjusted for GWI-status) and separately in VGWI and controls, on multivariable regression. Mitochondrial impairment and oxidative stress (OS) underlie AEs from many exposures irrespective of nominal specific mechanism. We hypothesize that mitochondrial toxicity and interrelated OS from pesticides and radiation position people on the steep part of the curve of mitochondrial impairment and OS versus symptom/biological disruption, amplifying impact of new exposures. Copper, meanwhile, is involved in critical OS detoxification processes.

Immunomodulatory effect of imidacloprid on macrophage RAW 264.7 cells

The neonicotinoid imidacloprid was promoted in the market because of widespread resistance to other insecticides, plus its low mammalian impact and higher specific toxicity towards insects. This study aimed to evaluate the immunomodulatory effect of imidacloprid on macrophages. RAW 264.7 cells were incubated to 0-4000mg/L of imidacloprid for 24 and 96h. Imidacloprid presented a concentration-dependent cytotoxicity after 24h and 96h incubation for MTT reduction (3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide) (EC₅₀ 519.6 and 324.6mg/L, respectively) and Neutral Red (3-amino-7-dimethylamino-2-methylphenazine hydrochloride) assays (EC₅₀ 1139.0 and 324.2mg/L, respectively). Moreover, imidacloprid decreased the cells' inflammatory response and promoted a mitochondrial depolarization. The complex II and succinate dehydrogenase (SDH) activities in RAW 264.7 cells incubated with imidacloprid increased more at 24h. These results suggest that imidacloprid exerts an immunomodulatory effect and mitochondria can act as regulator of innate immune responses in the cytotoxicity mediated by the insecticide in RAW 264.7 cells.

Long-term and low dose oral malathion exposure causes morphophysiological changes in the colon of rats

BACKGROUND

Malathion (MAL) is an organophosphate insecticide that inhibits cholinesterases, used to control pests in agriculture and to combat mosquitoes that transmit various arboviruses. As acetylcholine is one of the major neurotransmitters of the enteric nervous system (ENS), humans exposed to MAL by ingestion of contaminated food and water can develop symptoms due disfunction of the gastrointestinal tract. Although the deleterious effects after exposure to high doses are recognized, little is known about the long-term and low-dose effects of this pesticide on the structure and motility of the colon.

AIMS

to evaluate the effects of prolonged oral exposure to low levels of MAL on the wall structure and colonic motility parameters of young rats.

MAIN METHODS

The animals were divided into three groups: control, and groups that received 10 or 50 mg/kg of MAL via gavage for 40 days. The colon was collected for histological analysis and analysis of the ENS through the evaluation of total neurons and subpopulations of the myenteric and submucosal plexuses. Cholinesterase activity and functional analyzes of the colon were evaluated.

KEY FINDINGS

MAL treatments (10 and 50 mg/Kg) reduced the butyrylcholinesterase activity, and caused enlargement of faecal pellets, atrophy of muscle layers and several changes in neurons of both myenteric and submucosal plexi. Considering colonic contraction, MAL (50 mg/Kg) increased the number of retrograde colonic migratory motor complexes.

SIGNIFICANCE

The long-term exposure to low doses of MAL affects colonic morphophysiology, which highlights the need to intensify control and care in the use of this pesticide.

Potential protective effects of red grape seed extract in a rat model of malathion-induced neurotoxicity

Background and Aim: Exposure to pesticide mixtures used in agricultural practice poses a grave risk to non-target animals. This study aimed to determine whether red grape seed extract (RGSE, which is 95% bioflavonoids and equal to 12,000 mg of fresh red grape seed, and 150 mg of vitamin C) alleviated the changes in brain-derived neurotrophic factor (BDNF) level, acetylcholinesterase activity, oxidative stress, and apoptosis induced by orally administered malathion in a rat model of malathion-induced neurotoxicity. Materials and Methods: Thirty-two adult male Wistar albino rats were divided into four groups and exposed to malathion with or without 4 weeks of RGSE treatment, treated with RGSE alone, or left untreated as controls. The animals were euthanized 24 h after last treatment. Brain samples were collected to measure acetylcholinesterase, superoxide dismutase (SOD), and caspase 3 activity, total antioxidant capacity (TAC), and BDNF levels. Results: Malathion significantly reduced acetylcholinesterase and SOD activity and TAC and significantly increased caspase 3 activity. In comparison, acetylcholinesterase and SOC activity, BDNF level, and TAC were improved and caspase 3 activity was decreased in the malathion-RGSE group, indicating that RGSE corrected the alterations detected in these biochemical parameters. Conclusion: Oxidative stress and apoptosis in the brains of rats exposed to oral malathion were substantially controlled by RGSE treatment.

Mitochondrial dysfunction from malathion and chlorpyrifos exposure is associated with degeneration of GABAergic neurons in Caenorhabditis elegans

Toxicity resulting from off-target effects, beyond acetylcholine esterase inhibition, for the commonly used organophosphate (OP) insecticides chlorpyrifos (CPS) and malathion (MA) was investigated using Saccharomyces cerevisiae and Caenorhabditis elegans model systems. Mitochondrial damage and dysfunction were observed in yeast following exposure to CPS and MA, suggesting this organelle is a major target. In the C. elegans model, the mitochondrial unfolded protein response pathway showed the most robust induction from CPS and MA treatment among stress responses examined. GABAergic neurodegeneration was observed with CPS and MA exposure. Impaired movement observed in C. elegans exposed to CPS and MA may be the result of motor neuron damage. Our analysis suggests that stress from CPS and MA results in mitochondrial dysfunction, with GABAergic neurons sensitized to these effects. These findings may aid in the understanding of toxicity from CPS and MA from high concentration exposure leading to insecticide poisoning.

The effect of pesticides on the NADH-supported mitochondrial respiration of permeabilized potato mitochondria

Pesticides can seriously affect the respiratory chain of the mitochondria of many crops, reducing the intensity of plant growth and its yield. Studying the effect of pesticides on the bioenergetic parameters of intact plant mitochondria is a promising approach for assessing their toxicity. In this study, we investigated the effect of some pesticides on isolated potato mitochondria, which used exogenous NADH as a substrate for respiration. We showed that succinate is the most preferred substrate for phosphorylating respiration of intact potato tubers mitochondria. Potato mitochondria poorly oxidize exogenous NADH, despite of the presence of external NADH dehydrogenases. Permeabilization of the mitochondrial membrane with alamethicin increased the availability of exogenous NADH to complex I. However, the pathway of electrons through complex I to complex IV makes intact potato mitochondria susceptible to a number of pesticides such as difenoconazole, fenazaquin, pyridaben and tolfenpyrad, which strongly inhibit the rate of mitochondrial respiration. However, these pesticides only slightly inhibited the rate of oxygen consumption during succinate-supported respiration. Dithianon, the inhibitor of Complex II, is the only pesticide which significantly increased the respiratory rate of NADH-supported respiration of permeabilized mitochondria of potato. Thus, it can be assumed that the alternative NADH dehydrogenases for electron flow represent a factor responsible for plant resistance to xenobiotics, such as mitochondria-targeted pesticides.

Comparative assessment on the probable mechanisms underlying the hepatorenal toxicity of commercial imidacloprid and hexaflumuron formulations in rats

Pesticides are viewed as a major wellspring of ecological contamination and causing serious risky consequences for people and animals. Imidacloprid (IM) and hexaflumuron (HFM) are extensively utilized insect poisons for crop assurance on the planet. A few investigations examined IM harmfulness in rodents, but its exact mechanism hasn't been mentioned previously as well as the toxicity of HFM doesn't elucidate yet. For this reason, the present study was designed to explore the mechanism of each IM and HFM-evoked rat liver and kidney toxicity and to understand its molecular mechanism. 21 male Wistar albino rats were divided into 3 groups, as follows: group (1), normal saline; group (2), IM; and group (3), HFM. Both insecticides were orally administered every day for 28 days at a dose equal to 1/10 LD50 from the active ingredient. After 28 days postdosing, rats were anesthetized to collect blood samples then euthanized to collect liver and kidney tissue specimens. The results showed marked changes in walking, body tension, alertness, and head movement with a significant reduction in rats' body weight in both IM and HFM receiving groups. Significant increases in MDA levels and decrease of GHS levels were recorded in liver and kidney homogenates of either IM or HFM groups. Liver and kidney tissues obtained from both pesticide receiving groups showed extensive histopathological alterations with a significant increase in the serum levels of ALT, AST, urea, and creatinine and a decrease in total proteins, albumin, and globulin levels. In addition, there was upregulation of the transcript levels of casp-3, JNK, and HO-1 genes with strong immunopositivity of casp-3, TNF-ὰ, and NF-_KB protein expressions in the liver and kidneys of rats receiving either IM or HFM compared with the control group. In all studied parameters, HFM caused hepatorenal toxicity more than those induced by IM. We can conclude that each IM and HFM provoked liver and kidneys damage through overproduction of ROS, activation of NF-_KB signaling pathways and mitochondrial/JNK-dependent apoptosis pathway.

Crocin Protects Malathion-Induced Striatal Biochemical Deficits by Inhibiting Apoptosis and Increasing α-Synuclein in Rats' Striatum

Long-term exposure to organophosphates might result in neurodegenerative diseases, comprising Parkinson's disease. Malathion is an organophosphate pesticide with high neurotoxicity. Oxidative stress, apoptosis, and α-synuclein accumulation are important underlying mechanisms in Parkinson's disease. According to studies, crocin, an active constituent of saffron, has anti-apoptotic, anti-inflammatory, and antioxidant properties. Thus, the effect of crocin on malathion-induced striatal biochemical deficits in rats was investigated in this study. Six groups of male Wistar rats were used: 1. control (normal saline); 2. malathion (100 mg/kg/day, i.p.); 3. crocin (10 mg/kg/day, i.p.) + malathion; 4. levodopa (10 mg/kg/day, i.p.) + malathion; 5. crocin (40 mg/kg/day, i.p.); and 6. polyethylene glycol (PEG) (vehicle of levodopa) groups. The drugs were administered for 28 days. The amounts of Bcl-2, Bax, and caspases 3, 8, and 9 proteins in the striatum were measured by western blotting. Also, the amounts of protein and mRNA level of the α-synuclein in striatum tissue were measured by western blotting and RT-qPCR methods. Malathion induced apoptosis by increasing the amount of Bax/Bcl2 ratio and caspases 3 and 9 proteins in rat striatum tissue. It also increased the protein and mRNA level of α-synuclein in striatal tissue. Co-administration of crocin or levodopa with malathion inhibited the toxic effects of malathion on striatal tissue. Crocin ameliorates the neurotoxic effect of malathion by its anti-apoptotic activity and regulating the expression of proteins involved in Parkinson's disease pathogenesis. As a result, crocin has the potential to be used as a treatment for malathion-induced neurotoxicity.

A Common Feature of Pesticides: Oxidative Stress-The Role of Oxidative Stress in Pesticide-Induced Toxicity

Pesticides are important chemicals or biological agents that deter or kill pests. The use of pesticides has continued to increase as it is still considered the most effective method to reduce pests and increase crop growth. However, pesticides have other consequences, including potential toxicity to humans and wildlife. Pesticides have been associated with increased risk of cardiovascular disease, cancer, and birth defects. Labels on pesticides also suggest limiting exposure to these hazardous chemicals. Based on experimental evidence, various types of pesticides all seem to have a common effect, the induction of oxidative stress in different cell types and animal models. Pesticide-induced oxidative stress is caused by both reactive oxygen species (ROS) and reactive nitrogen species (RNS), which are associated with several diseases including cancer, inflammation, and cardiovascular and neurodegenerative diseases. ROS and RNS can activate at least five independent signaling pathways including mitochondrial-induced apoptosis. Limited in vitro studies also suggest that exogenous antioxidants can reduce or prevent the deleterious effects of pesticides.

Temporal exposure to malathion: Biochemical changes in the Amazonian fish tambaqui, Colossoma macropomum

The main toxicity mechanism of organophosphate insecticides such as malathion is the acetylcholinesterase enzyme inhibition. However, fish responses to organophosphates may vary depending on the activation of different defense mechanisms as well as the length of exposure. As such, the evaluation of acetylcholinesterase activity, in combination with the evaluation of biotransformation and antioxidants enzymes levels, is useful for indicating damage in fish exposed to this insecticide. Moreover, evaluating mitochondrial activity might evidence how the hierarchic responses occur in relation to the length of time that the fish is exposed. Therefore, the aim of our study is to evaluate whether the length of exposure to malathion differentially affects the biochemical responses of tambaqui. Our hypothesis is that the physiological alterations due to exposure are time dependent. Fish were exposed to sublethal concentrations of the insecticide during 6, 12, 24, 36, and 48 h. Contrary to expectations, there was no acetylcholinesterase activity inhibition during the experiment, which indicates an absence of neurotoxicity. Phase II biotransformation mechanism was activated early, especially in the liver. Oxidative damage was evident in the first hours of exposure and was concurrent with the activation of antioxidant enzymes. Mitochondrial bioenergetics were differentially affected by the length of exposure. The data suggest that the tambaqui regulates mitochondrial respiration differently over time, seeking to maintain homeostasis and ATP demand, and ensures the activation of response mechanisms, thus minimizing oxidative damage and avoiding the neurotoxicity of malathion.

Organophosphorus pesticides exhibit compound specific effects in rat precision-cut lung slices (PCLS): mechanisms involved in airway response, cytotoxicity, inflammatory activation and antioxidative defense

Organophosphorus compound pesticides (OP) are widely used in pest control and might be misused for terrorist attacks. Although acetylcholinesterase (AChE) inhibition is the predominant toxic mechanism, OP may induce pneumonia and formation of lung edema after poisoning and during clinical treatment as life-threatening complication. To investigate the underlying mechanisms, rat precision-cut lung slices (PCLS) were exposed to the OP parathion, malathion and their biotransformation products paraoxon and malaoxon (100–2000 µmol/L). Airway response, metabolic activity, release of LDH, cytokine expression and oxidative stress response were analyzed. A concentration-dependent inhibition of airway relaxation was observed after exposure with the oxon but not with the thion-OP. In contrast, cytotoxic effects were observed for both forms in higher concentrations. Increased cytokine expression was observed after exposure to parathion and paraoxon (IL-6, GM-CSF, MIP-1α) and IL-6 expression was dependent on NFκB activation. Intracellular GSH levels were significantly reduced by all four tested OP but an increase in GSSG and HO-1 expression was predominantly observed after malaoxon exposure. Pretreatment with the antioxidant N-acetylcysteine reduced malaoxon but not paraoxon-induced cytotoxicity. PCLS as a 3D lung model system revealed OP-induced effects depending on the particular OP. The experimental data of this study contribute to a better understanding of OP toxicity on cellular targets and may be a possible explanation for the variety of clinical outcomes induced by different OP.

Alleviation of Malathion Toxicity Effect by Coffea arabica L. Oil and Olea europaea L. Oil on Lipid Profile: Physiological and In Silico Study

The community health plans commonly use malathion (MAL), an organophosphate pesticide (OP), to eliminate pathogenic insects. The objective of the present research is to evaluate the consequences of Coffea arabica L. oil and Olea europaea L. oil on MAL-intoxicated male rats. Six equal groups of animals were used for conducting this study (n = 10). Animals in group one were designated as control, animals belonging to group two were exposed to MAL in the measure of hundred mg per kg BW (body weight) for forty-nine days (seven weeks), rats in the third and fourth groups were administered with 400 mg/kg BW of Coffea arabica L. and Olea europaea L. oils, respectively, and the same amount of MAL as given to the second group. Groups five and six were administered with the same amount of Coffea arabica L. oil and Olea europaea L. oil as given to group three. Exposure of rats to 100 mg/kg body weight of MAL resulted in statistical alteration of the serum lipid profile. A marked decline was noticed in the severe changes of these blood parameters when MAL-intoxicated rats were treated with Coffea arabica L. oil and Olea europaea L. oil. Two compounds from Coffea arabica L. oil (Chlorogenic acid) and Olea europaea L. oil (Oleuropein) demonstrated good interaction with xanthine oxidase (XO) and 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGR) enzymes that are associated with cholesterol production. The present study indicated that Coffea arabica L. oil and Olea europaea L. oil could be considered prospective and potential healing agents against metabolic conditions induced by MAL.

Protective Effect of Crocin on Malathion-induced Cardiotoxicity in Rats: A Biochemical, Histopathological and Proteomics Study

In this study, the protective effect of crocin on malathion (MTN) induced cardiotoxicity in rats in subacute exposure was evaluated. Rats were divided into 6 groups; control (normal saline); MTN (100 mg/kg); MTN + crocin (10, 20 and 40 mg/kg) and MTN + vitamin E 200 IU/kg. Treatments were continued for two weeks. Creatine phosphokinase MB (CK-MB), malondialdehyde (MDA) and glutathione (GSH) levels were evaluated in heart tissue at the end of treatments. The effect of crocin and MTN on histopathological changes in rat cardiac tissue was also investigated. The alteration of protein profile in the heart of the animals exposed to MTN was evaluated by proteomic approach through two-dimensional gel electrophoresis followed by matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) software. MTN induced histopathological damages and elevated the level of cardiac marker CK-MB (P < 0.01). The level of MDA increased and the level of GSH reduced (P < 0.001). MDA levels were reduced in all crocin plus MTN groups (P < 0.001) and vitamin E plus MTN (P < 0.001) groups as compared to MTN groups. However, in the crocin (10 mg/kg) + MTN group, the content of GSH compared to MTN treated rats increased (P < 0.001). Protein abundance analysis identified proteins implicated in cardiac necrosis, tricarboxylic acid cycle, cellular energy homeostasis, arrhythmias, heart development, heart failure and cardiovascular homeostasis to be affected by MTN. In summary, MTN may induce damage in the heart tissue of rats following subacute exposure and crocin, as an antioxidant, showed protective effects against MTN cardiotoxicity.

Fipronil induced oxidative stress in neural tissue of albino rat with subsequent apoptosis and tissue reactivity

Fipronil (FIP) insecticide is extensively used in agriculture, public health and veterinary medicine. Although it is considered as a neurotoxin to insects (target organisms) and exhibits neurological signs upon vertebrates (non-target organisms) exposure, slight is known about its potential neurotoxic effects and its molecular mechanisms on vertebrates. The current study is designed to assess oxidative stress as a molecular mechanism of FIP neurotoxicity subordinated with apoptosis and neural tissue reactivity. Ten adult male albino rats received 10 mg/kg body weight fipronil technical grade by oral gavage daily for 45 days (subacute exposure). Brain neural tissue regions (hippocampus, cerebellum and caudate putamen) were processed to examine oxidative stress induced cellular macromolecular alterations as MDA, PCC and DNA fragmentation. Besides, TNF-α and Bcl-2 gene expression and immunoreactivity for caspase-3 (active form), iNOS and GFAP were evaluated. Also, histopathological assessment was conducted. We found that FIP significantly raised MDA, PCC and DNA fragmentation (p ≤ 0.05). Also, it significantly upregulated TNF-α and non-significantly down-regulated Bcl-2 gene expression (p ≤ 0.05). Further, significant increased immunoreactivity to GFAP, iNOS and caspase-3 (active form) in these brain neural tissue regions in FIP treated group was noticed (p ≤ 0.05). Histopathological findings, including alterations in the histological architecture and neuronal degeneration, were also observed in these brain regions of FIP treated group. In conclusion, we suggest the ability of FIP to induce oxidative stress mediated macromolecular alterations, leading to apoptosis and tissue reaction in these brain regions which showed variable susceptibility to FIP toxic effects.

Biochemical changes and antioxidant capacity of naringin and naringenin against malathion toxicity in Saccharomyces cerevisiae

Flavonoids are rich in seeds, citrus fruits, olive oil, tea and red wine. Citrus flavonoids constitute an important type of flavonoids. Naringin and naringenin belong to flavonoids with known antioxidant and were found to display antioxidant activities. Malathion is an organophosphorus pesticide that has been broadly used throughout the world to control weeds and pests. It has also been used in public health for mosquito control and fruit fly eradication programs. Malathion, naringin, and naringenin were added to be in 40, 80, and 160 mg doses in Saccharomyces cerevisiae cultures mainly used to determine the antioxidant capacity, it is known that they have shown similar results to man. At the end of the experiment, total protein, malondialdehyde (MDA), reduced glutathione (GSH), oxidized glutathione (GSSG), vitamin K, vitamin E, vitamin D, ergosterol, stigmasterol, β-Sitosterol, and fatty acids were analyzed by HPLC (high performance liquid chromatography) and GC (gas chromatography) devices in the tested S. cerevisiae samples. The contents of the yeast cell of octanoic acid (C8:0), lauric acid (C12:0), myristic acid (C14:0), palmitic acid (C16:0), palmitoleic acid (C16:1n-7), heptadecanoic acid (C17:0), stearic acid (C18:0), oleic acid (C18:1n-9), and linoleic acid (C18:2n-6) were identified. There were statistically significant changes in total protein, MDA, GSH, GSSG, vitamin K, vitamin E, vitamin D, phytosterol and fatty acid levels. It was determined that naringin and naringenin showed statistically significant decreases against malathion toxicity on these parameters. From this study it is found that, the mitigating effect of naringin against DPPH stable free radical was higher than that of naringenin. Citrus flavonoid, naringin showed promising antioxidant activity which can be used as effective protecting agents against oxidative stress.

The effect of pesticides on the mtDNA integrity and bioenergetic properties of potato mitochondria

Potato (Solanum tuberosum L.) is one of the most common crops in the world, and it is very susceptible to a wide range of pests such as insects and fungi. The use of pesticides often results in the suppression of seed germination and plant growth, in particular, due to their effect on the respiratory chain of mitochondria. There are numerous studies of the effect of pesticides on animal mitochondria, but their interference with the electron transport in plant mitochondria is not well documented. We present the data showing that a number of pesticides inhibit electron flow, and other pesticides uncouple the respiratory chain. Among the studied pesticides engaging the alternative pathways of electron transport, dithianon led to an increase in the rate of H₂O₂ production but did not cause a strong increase in the amount of mtDNA damage as compared to other pesticides. In general, the main negative effect of the studied pesticides is manifested in a decrease of membrane potential with the maintenance of the rate of oxygen consumption and a low rate of H₂O₂ production. The mtDNA damage is caused mainly by pesticides belonging to the pyrethroid class and remains minor as compared to its damage in animals. Our data indicate that the respiratory chain of plant mitochondria is more resistant to pesticides as compared to animal mitochondria due to the presence of the alternative pathways of electron transport.

Organophosphate toxicity: updates of malathion potential toxic effects in mammals and potential treatments

Organophosphorus insecticides toxicity is still considered a major global health problem. Malathion is one of the most commonly used organophosphates nowadays, as being considered to possess relatively low toxicity compared with other organophosphates. However, widespread use may lead to excessive exposure from multiple sources. Mechanisms of MAL toxicity include inhibition of acetylcholinesterase enzyme, change of oxidants/antioxidants balance, DNA damage, and facilitation of apoptotic cell damage. Exposure to malathion has been associated with different toxicities that nearly affect every single organ in our bodies, with CNS toxicity being the most well documented. Malathion toxic effects on liver, kidney, testis, ovaries, lung, pancreas, and blood were also reported. Moreover, malathion was considered as a genotoxic and carcinogenic chemical compound. Evidence exists for adverse effects associated with prenatal and postnatal exposure in both animals and humans. This review summarizes the toxic data available about malathion in mammals and discusses new potential therapeutic modalities, with the aim to highlight the importance of increasing awareness about its potential risk and reevaluation of the allowed daily exposure level.

The evaluation of oxidative damage of DNA after poisoning with nerve agents

The potency of three nerve agents (sarin, soman, tabun) to induce oxidative damage of DNA in lymphocytes, liver and brain during lethal or sublethal poisoning was investigated. The single strand breaks or oxidative base DNA damage was evaluated with the help of Comet assay and a specific enzyme able to detect oxidative bases of DNA (endonuclease III). While sarin and soman administered at sublethal doses corresponding to 50% of their LD50 values were not able to induce oxidative damage of DNA, their lethal dose (LD50) induced the significant increase of the number of oxidative bases in DNA of hepatocytes. In addition, tabun administered at lethal dose (LD50) induced significant increase of the number of single strand breaks and oxidative bases of DNA in glial cells isolated from pontomedullar brain region. Thus, some nerve agents were able to induce oxidative damage in the peripheral as well as central compartment but only in the case of severe poisoning caused by lethal doses of nerve agents. This non-cholinergic effect of nerve agents has probably consequences with nerve agents-induced hypoxic status during acute cholinergic crisis and it can contribute to their long-term toxic effects.

Modulatory effects of swimming exercise against malathion induced neurotoxicity in male and female rats

Malathion is one of the most commonly used organophosphorus (OP) pesticides. It is important to regard that exposure to OP poisoning may cause anxiety and depression. Malathion toxicity induces cholinergic symptoms. Brain-derived neurotrophic factor (BDNF) is the most profusely expressed neurotrophin in the central nervous system; it promotes the survival of neurons. Regular exercise improves brain well-being and enhances recovery from brain Injuries. It is suggested that BDNF may mediate these effects. Therefore, this study was planned to assess the modulatory effects of regular exercise performance on brain BDNF level, cholinergic activity, oxidative stress and apoptosis in male and female rats subjected to neurotoxicity induced by malathion administration.

MATERIALS AND METHODS

Thirty-two adult male and thirty-two adult female albino rats were included in this study. The rats were divided into four equal groups (8rats). Control group, malathion treated group, exercised group, malathion exercised group. Acetylcholinesterase (AchE) activity, total antioxidant capacity (TAC), BDNF level and Caspase 3 activity were assessed.

RESULTS

Female rats had higher baseline content of BDNF in brain homogenate than male rats. Malathion administration induced a significant decrease in BDNF level in female rats and in the total antioxidant capacity in both male and female rats. A significant elevation in caspase 3 activity was detected in the malathion treated groups, with more elevation in female rats. Swimming exercise improved BDNF level, AchE activity, and apoptosis in both male and female rats in all groups. In addition, male rats were more cholinergic system responders to regular exercise than female rats.

CONCLUSION

It could be concluded that malathion induced elevation in oxidative stress and apoptosis in all rats, with reduction in BDNF level in female rats. Meanwhile, regular swimming exercise was found to improve brain health through modulation of BDNF level and cholinergic activity. It is recommended to practice regular exercise to maintain brain health. Further studies are required to clarify the involvement of sex hormones in BDNF regulation.

Different Toxic Effects of Racemate, Enantiomers, and Metabolite of Malathion on HepG2 Cells Using High-Performance Liquid Chromatography-Quadrupole-Time-of-Flight-Based Metabolomics

Commercial malathion is a racemic mixture that contains two enantiomers, and malathion has adverse effects on mammals. However, whether these two enantiomers have different effects on animals remains unclear. In this study, we tested the effect of racemate, enantiomers, and metabolite of malathion on the metabolomics profile of HepG2 cells. HepG2 cells showed distinct metabolic profiles when treated with rac-malathion, malaoxon, R-(+)-malathion, and S-(-)-malathion, and these differences were attributed to pathways in amino acid metabolism, oxidative stress, and inflammatory response. In addition, malathion treatment caused changes in amino acid levels, antioxidant activity, and expression of inflammatory genes in HepG2 cells. S-(-)-Malathion exhibited stronger metabolic perturbation than its enantiomer and racemate, consistent with the high level of cytotoxicity of S-(-)malathion. R-(+)-Malathion treatment caused significant oxidative stress in HepG2 cells but induced a weaker disturbance in the amino acid metabolism and a pro-inflammatory response compared to S-(-)-malathion and rac-malathion. Malaoxon caused more significant perturbation on antioxidase and a stronger antiapoptosis effect than its parent malathion. Our results provide insight into the risk assessment of malathion enantiomers and metabolites. We also demonstrate that a metabolomics approach can identify the discrepancy of the toxic effects and underlying mechanisms for enantiomers and metabolites of chiral pesticides.

The protective effects of the antioxidant N-acetylcysteine (NAC) against oxidative stress-associated apoptosis evoked by the organophosphorus insecticide malathion in normal human astrocytes

Malathion is one of the most widely used organophosphorus insecticides in agriculture. However, malathion may be involved in the etiology of human brain dysfunction. Induction of ROS has been proposed as a mechanism of malathion-induced poisoning cases, but there are few data regarding the effects of malathion on oxidative stress-associated neurotoxicity in human glial cells. The aim was to explore the mechanism underlying effects of malathion on neurotoxicity in Gibco^® Human Astrocytes (GHA cells) and evaluate the protective effects of the antioxidant (N-acetylcysteine, NAC). Cell viability was measured by the cell proliferation reagent (WST-1). Antioxidant enzymes (glutathione peroxidase and catalase) were measured by an ELISA reader. Cell cycle distribution and ROS productions were detected by flow cytometry. Cell cycle-related protein levels (cyclin E1, CDK2, cyclin A2, CDK1/CDC2, or cyclin B1) and apoptotic protein levels (Bcl-2, Bax, and cleaved caspase-9/caspase-3) were analyzed by Western blotting. In GHA cells, treatment with malathion (10-25 μM) for 24 h concentration-dependently induced cytotoxicity and cell cycle arrest. In terms of oxidative stresses, malathion elevated intracellular ROS levels, but reduced glutathion and antioxidant enzyme levels. Treatment with NAC (5 μM) reversed malathion-induced oxidative stress responses, and prevented malathion-evoked apoptosis by regulating apoptotic protein expressions. Together, in GHA cells, NAC mediated inhibition of malathion-activated mitochondrial apoptotic pathways that involved cell cycle arrest and ROS responses. These data provide further insights into the molecular mechanisms behind malathion poisoning, and might suggest that NAC with its protective effects may be a potential compound for prevention of malathion-induced brain injury.

Neuroprotective potential of crocin against malathion-induced motor deficit and neurochemical alterations in rats

In several epidemiological studies, an association between pesticide exposure and the incidence of Parkinson's disease (PD) has been reported. Increasing evidence showed that oxidative stress plays an important role in the pathogenesis of PD. The present study investigated the preventive effect of crocin, saffron active components, on malathion (an organophosphate pesticide (OP))-induced Parkinson-like behaviors in rat. Rats were divided into eight groups: control (normal saline), malathion (100 mg/kg/day, i.p), crocin (10, 20, or 40 mg/kg/day, i.p) plus malathion, levodopa (10 mg/kg/day, i.p) plus malathion, crocin (40 mg/kg/day, i.p), and PEG (vehicle of levodopa) groups. Treatments were continued for 28 days. The neurobehavioral tests which include open field, rotarod and catalepsy were performed on day 28. The activity of acetylcholinesterase (AChE) in serum, the levels of malondialdehyde (MDA), reduced glutathione (GSH), TNF-α, and IL-6 in striatum at the end of treatments were evaluated. Results showed that malathion induced neurobehavioral impairments together with elevation of MDA, TNF-α and IL-6 levels, reduction of GSH, and AChE activity. Crocin (10, 20, and 40 mg/kg) improved neurobehavioral impairments induced by malathion but not AChE activity. Crocin (10, 20, and 40 mg/kg) or levodopa plus malathion decreased MDA and increased GSH. Also crocin (10 mg/kg) decreased TNF-α and IL-6 levels in striatum. In summary, subchronic malathion exposure induced Parkinson-like behavior in rat. Crocin exhibited protective effects against malathion-induced Parkinson-like behavior through reducing lipid peroxidation, improvement of motor deficit and anti-inflammatory effects.

Adverse effects of organophosphorus pesticides on the liver: a brief summary of four decades of research

Organophosphorus pesticides (OPs) are widely used volatile pesticides that have harmful effects on the liver in acute and chronic exposures. This review article summarises and discusses a wide collection of studies published over the last 40 years reporting on the effects of OPs on the liver, in an attempt to propose general mechanisms of OP hepatotoxicity and possible treatment. Several key biological processes have been reported as involved in OP-induced hepatotoxicity such as disturbances in the antioxidant defence system, oxidative stress, apoptosis, and mitochondrial and microsomal metabolism. Most studies show that antioxidants can attenuate oxidative stress and the consequent changes in liver function. However, few studies have examined the relationship between OP structures and the severity and mechanism of their action. We hope that future in vitro, in vivo, and clinical trials will answer the remaining questions about the mechanisms of OP hepatotoxicity and its management.

Malathion, an organophosphate insecticide, provokes metabolic, histopathologic and molecular disorders in liver and kidney in prepubertal male mice

The present study was undertaken to determine the effects of malathion exposure on oxidative stress, functional and metabolic parameters in kidney and liver of prepubertal male mice. For this reason, two separated groups of prepubertal male mice were used in this experiment. Animals were divided into two groups, group 1 served as a control and received the corn oil and group 2 was treated with 200 mg/kg body weight (b.w.) of malathion for 30 days. In result, we found that the malathion administration led to the perturbation of biochemical markers and histopathological as well as molecular damages. These changes were accompanied by an oxidative alternation which was evaluated by lipoperoxidation process and MDA production, a diminution of sulfhydril groups (-SH) content and an antioxidant enzyme activities depletion such as total superoxide dismutase (SOD) and its isoforms, catalase (CAT) and glutathione peroxidase (GPx) in both kidney and liver tissues. These changes were related with many histopathological lesions in the liver and kidney tissues. More importantly, this insecticide clearly caused a decline in the GPx-4 expression in liver as well as GPx-3 in kidney. These data suggest that prepubertal male mice exposure to malathion showed a marked deregulation of liver and kidney functions.

Nitric oxide synthase inhibitors protect against brain and liver damage caused by acute malathion intoxication

OBJECTIVE

To investigate the effect of N^G-nitro-l-arginine methyl ester (l-NAME), a non-selective nitric oxide synthase (NOS) inhibitor, and 7-nitroindazole (7-NI), a selective neuronal NOS inhibitor, on oxidative stress and tissue damage in brain and liver and on DNA damage of peripheral blood lymphocytes in malathion intoxicated rats.

METHODS

Malathion (150 mg/kg) was given intraperitoneally (i.p.) along with l-NAME or 7-NI (10 or 20 mg/kg, i.p.) and rats were euthanized 4 h later. The lipid peroxidation product malondialdehyde (MDA), nitric oxide (nitrite), reduced glutathione (GSH) concentrations and paraoxonase-1 (PON-1) activity were measured in both brain and liver. Moreover, the activities of glutathione peroxidase (GPx) acetylcholinesterase (AChE), and butyrylcholinesterase (BChE), total antioxidant capacity (TAC), glucose concentrations were determined in brain. Liver enzyme determination, Comet assay, histopathological examination of brain and liver sections and inducible nitric oxide synthase (iNOS) immunohistochemistry were also performed.

RESULTS

(i) Rats treated with only malathion exhibited increased nitric oxide and lipid peroxidation (malondialdehyde) accompanied with a decrease in GSH content, and PON-1 activity in brain and liver. Glutathione peroxidase activity, TAC, glucose concentrations, AChE and BChE activities were decreased in brain. There were also raised liver aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities and increased DNA damage of peripheral blood lymphocytes (Comet assay). Malathion caused marked histopathological changes and increased the expression of iNOS in brain and liver tissues. (ii) In brain of malathion-intoxicated rats, l-NAME or 7-NI resulted in decreased nitrite and MDA contents while increasing TAC and PON1 activity. Reduced GSH and GPx activity showed an increase by l-NAME. AChE activity increased by 20 mg/kg l-NAME and 10 mg/kg 7-NI. AChE activity decreased by the higher dose of 7-NI while either dose of 7-NI resulted in decreased BChE activity. (iii) In liver of malathion-intoxicated rats, decreased MDA content was observed after l-NAME or 7-NI. Nitrite level was unchanged by l-NAME but increased after 7-NI which also resulted in decreased GSH concentration and PON1 activity. Either inhibitor resulted in decreased liver ALT activity. (iv) DNA damage of peripheral blood lymphocytes was markedly inhibited by l-NAME or 7-NI treatment. (v) iNOS expression in brain and liver decreased by l-NAME or 7-NI. (vi) More marked improvement of the histopathological alterations induced by malathion in brain and liver was observed after 7-NI compared with l-NAME.

CONCLUSIONS

In malathion intoxicated rats, the neuronal NOS inhibitor 7-NI and to much less extent l-NAME were able to protect the brain and liver tissue integrity along with improvement in oxidative stress parameters. The decrease in DNA damage of peripheral blood lymphocytes by NOS inhibitors also suggests the involvement of nitric oxide in this process.

Oxidative stress as a damage mechanism in porcine cumulus-oocyte complexes exposed to malathion during in vitro maturation

Malathion is one of the most commonly used insecticides. Recent findings have demonstrated that it induces oxidative stress in somatic cells, but there are not enough studies that have demonstrated this effect in germ cells. Malathion impairs porcine oocyte viability and maturation, but studies have not shown how oxidative stress damages maturation and which biochemical mechanisms are affected in this process in cumulus-oocyte complexes (COCs). The aims of the present study were to determine the amount of oxidative stress produced by malathion in porcine COCs matured in vitro, to define how biochemical mechanisms affect this process, and determine whether trolox can attenuate oxidative damage. Sublethal concentrations 0, 750, and 1000 µM were used to evaluate antioxidant enzyme expressions, reactive oxygen species (ROS production), protein oxidation, and lipid peroxidation, among other oxidation products. COCs viability and oocyte maturation decreased in a concentration-dependent manner. Malathion increased Cu, Zn superoxide dismutase (SOD1), glutathione-S-transferase (GST), and glucose 6 phosphate dehydrogenase (G6PD) protein level and decreased glutathione peroxidase (GSH-Px) and catalase (CAT) protein level. Species reactives of oxygen (ROS), protein oxidation and Thiobarbituric acid reactive substances (TBARS) levels increased in COCs exposed to the insecticide, but when COCs were pre-treated with the trolox (50 µM) 30 min before and during malathion exposure, these parameters decreased down to control levels. This study showed that malathion has a detrimental effect on COCs during in vitro maturation, inducing oxidative stress, while trolox attenuated malathion toxicity by decreasing oxidative damage.

Developmental neurotoxic effects of Malathion on 3D neurosphere system

Developmental neurotoxicity (DNT) refers to the toxic effects induced by various chemicals on brain during the early childhood period. As human brains are vulnerable during this period, various chemicals would have significant effects on brains during early childhood. Some toxicants have been confirmed to induce developmental toxic effects on CNS; however, most of agents cannot be identified with certainty. This is because available animal models do not cover the whole spectrum of CNS developmental periods. A novel alternative method that can overcome most of the limitations of the conventional techniques is the use of 3D neurosphere system. This in-vitro system can recapitulate many of the changes during the period of brain development making it an ideal model for predicting developmental neurotoxic effects. In the present study we verified the possible DNT of Malathion, which is one of organophosphate pesticides with suggested possible neurotoxic effects on nursing children. Three doses of Malathion (0.25 μM, 1 μM and 10 μM) were used in cultured neurospheres for a period of 14 days. Malathion was found to affect proliferation, differentiation and viability of neurospheres, these effects were positively correlated to doses and time progress. This study confirms the DNT effects of Malathion on 3D neurosphere model. Further epidemiological studies will be needed to link these results to human exposure and effects data.

Evaluation of acetylcholinesterase in an animal model of mania induced by D-amphetamine

The present study aims to investigate the effects of mood stabilizers, lithium (Li) and valproate (VPA), on acetylcholinesterase (AChE) activity in the brains of rats subjected to an animal model of mania induced by D-amphetamine (D-AMPH). In the reversal treatment, Wistar rats were first given D-AMPH or saline (Sal) for 14 days. Between days 8 and 14, the rats were treated with Li, VPA, or Sal. In the prevention treatment, rats were pretreated with Li, VPA, or Sal. AChE activity was measured in the brain structures (prefrontal cortex, hippocampus, and striatum). Li, alone in reversion and prevention treatments, increased AChE activity in the brains of rats. VPA, alone in prevention treatment, increased AChE activity in all brain regions evaluated; in the reversion, only in the prefrontal. However, D-AMPH decreased activity of AChE in the striatum of rats in both the reversion and prevention treatments. VPA was able to revert and prevent this AChE activity alteration in the rat striatum. Our findings further support the notion that the mechanisms of mood stabilizers also involve changes in AChE activity, thus reinforcing the need for more studies to better characterize the role of acetylcholine in bipolar disorder.

Mechanisms of muscular electrophysiological and mitochondrial dysfunction following exposure to malathion, an organophosphorus pesticide

Muscle dysfunction in acute organophosphorus (OP) poisoning is a cause of death in human. The present study was conducted to identify the mechanism of action of OP in terms of muscle mitochondrial dysfunction. Electromyography (EMG) was conducted on rats exposed to the acute oral dose of malathion (400 mg/kg) that could inhibit acetylcholinesterase activity up to 70%. The function of mitochondrial respiratory chain and the rate of production of reactive oxygen species (ROS) from intact mitochondria were measured. The bioenergetic pathways were studied by measurement of adenosine triphosphate (ATP), lactate, and glycogen. To identify mitochondrial-dependent apoptotic pathways, the messenger RNA (mRNA) expression of bax and bcl-2, protein expression of caspase-9, mitochondrial cytochrome c release, and DNA damage were measured. The EMG confirmed muscle weakness. The reduction in activity of mitochondrial complexes and muscular glycogen with an elevation of lactate was in association with impairment of cellular respiration. The reduction in mitochondrial proapoptotic stimuli is indicative of autophagic process inducing cytoprotective effects in the early stage of stress. Downregulation of apoptotic signaling may be due to reduction in ATP and ROS, and genotoxic potential of malathion. The maintenance of mitochondrial integrity by means of artificial electron donors and increasing exogenous ATP might prevent toxicity of OPs.

Alteration of the kidney membrane proteome of Mizuhopecten yessoensis induced by low-level methyl parathion exposure

Methyl parathion (MP) is a widely used organophosphorus pesticide that causes severe health and environmental effects. We investigated the alteration of the proteomic profile in the membrane enriched fraction of the kidneys of the scallop Mizuhopecten yessoensis exposed to low-level MP. Gas chromatography analysis showed that MP residues were significantly accumulated in the kidneys and the digestive glands of the scallops. According to two-dimensional electrophoresis, 17 proteins were differentially modulated under MP exposure. The mRNA expressions of 12 differential proteins were analyzed using quantitative PCR, and 10 showed consistent alteration of mRNA level with that of protein expression level. Altered expressions of two proteins (mitochondrial processing peptidase and α-tubulin) were also examined using Western blotting, showing that the mitochondrial processing peptidase was down-regulated but α-tubulin remained unchanged in response to MP exposure. Subcellular locations of all the identified proteins that were predicted using bioinformatics tools indicate that few of them are permanently located in the membrane. The differentially expressed proteins are involved in several critical biological processes, and their relevance to human health has been illuminated. These data taken together have provided some novel insights into the chronic toxicity mechanism of MP and have suggested mitochondrial processing peptidase as a potential biomarker for human health and environmental monitoring.

Protective efficacy of 2-PAMCl, atropine and curcumin against dichlorvos induced toxicity in rats

The effect of 2- pyridine aldoxime methyl chloride (2-PAMCl) and atropine with or without curcumin was investigated in dichlorvos (2,2-dichlorovinyl dimethyl phosphate; DDVP) induced toxicity in rats. Rats were exposed to DDVP (2 mg/kg sub-cutaneously) once daily for the period of 21 days. Post DDVP exposure, rats were further treated with 2-PAMCl (50 mg/kg intramuscular, once daily) + atropine (10 mg/kg, i.m. once daily) with or without curcumin (200 mg/kg; oral; once daily) for further 21 days. We observed a significant increase in lipid peroxidation (LPO), reactive oxygen species (ROS), oxidized glutathione (GSSG), while there was a significant decrease in antioxidant enzymes, brain acetylcholinesterase (AChE) and 5-hydroxy tryptamine (5-HT) activity on DDVP exposure of rats. These alterations were restored significantly by co-administration of 2-PAMCl + atropine in DDVP exposed rats. Curcumin when co-supplemented with 2-PAMCl + atropine also significantly protected serum aspartate aminotransferase (AST) and restored brain AChE activity and 5-HT level in animals sub-chronically exposed to DDVP. Histopathological observations along with biochemical changes in rat blood and tissues revealed significant protection offered by 2-PAMCl + atropine against DDVP. The results indicate that DDVP-induced toxicity can be significantly protected by co-administration of 2-PAMCl + atropine individually, however, curcumin co-supplementation with 2-PAMCl + atropine provides more pronounced protection, concerning particularly neurological disorders.

Cytotoxicity and DNA damage of five organophosphorus pesticides mediated by oxidative stress in PC12 cells and protection by vitamin E

Previous studies have demonstrated that pesticides could induce cytotoxicity and genotoxicity in vivo and in vitro, and that oxidative stress may be an important factor involved. However, investigations comparing the capability of different organophosphorous (OP) compounds to induce cytotoxicity, genotoxicity and oxidative stress are limited. Hence, the aim of this paper was to access the cytotoxic and genotoxic effects of five OPs or metabolites, Acephate (ACE), Methamidophos (MET), Chloramidophos (CHL), Malathion (MAT) and Malaoxon (MAO), and to clarify the role of oxidative stress, using PC12 cells. The results demonstrated that MET, MAT and MAO caused significant inhibition of cell viability and increased DNA damage in PC12 cells at 40 mg L(-1). MAO was more toxic than the other OPs. ACE, MET, MAT and MAO increased the levels of intracellular reactive oxygen species (ROS) and malondialdehyde (MDA), and decreased the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) at 20 mg L(-1) and 40 mg L(-1) to different degrees. Pre-treatment with vitamin E(600 μM)caused a significant attenuation in the cytotoxic and genotoxic effect; pre-treatment reversed subsequent OP-induced elevation of peroxidation products and the decline of anti-oxidant enzyme activities. These results indicate that oxidative damage is likely to be an initiating event that contributes to the OP-induced cytotoxicity.

Malathion and fenvalerate induce micronuclei in mouse bone marrow cells

Health effects of pesticides are a major public health concern. In this study, the genotoxic effects of two commonly-used pesticides, malathion, and fenvalerate, were investigated in mice in vivo. Induction of micronuclei in bone marrow cells was used as the test parameter following exposure to 2.5, 5 or 10 mg/kg malathion by intraperitoneal (i.p.) or per oral (p.o.) exposure. Exposure by both routes was found to cause a significant increase in micronucleated polychromatic erythrocytes (PCEs) in a dose-dependent manner (r = 0.9769; P < 0.05). The highest dose (10 mg/kg) induced significant (P < 0.05) cytotoxicity. In contrast, fenvalerate caused an increase in micronucleated PCEs only at higher doses (10 and 20 mg/kg) via i.p. injection, and was not associated with cytotoxicity. A significant dose-response correlation was not observed in the dose ranges tested for fenvalerate (r = 0.8704; P > 0.05). The results suggest that technical grade malathion is a genotoxic agent. In contrast, technical grade fenvalerate appears to be a potent genotoxic agent, but this observation should be confirmed with further investigation(s).