Symptoms indicative of the effects of organic solvent exposure in Dutch painters

The report describes the results of a cross-sectional study among two groups of young and older painters and two age-matched control groups. The study was intended to gather information on the occurrence of solvent-exposure symptoms among Dutch workers using a mailed questionnaire. Results indicated that among young painters and to a lesser extent among older painters what is commonly accepted as specific symptoms and additional solvent-related symptoms showed a higher frequency than among the controls. The most interesting observation was a significant relationship between the frequency of periods of heavy exposure and the severity of most symptom categories, whereas there was a lack of consistent relationships with other exposure parameters.     

Effects of solvent exposure on testosterone levels and butyrylcholinesterase activity in mice

In female and male mice the effect of exposure to trichloroethylene (TCE) seen at the lowest concentration is an increase in liver weight. The activity of plasma butyrylcholinesterase (BuChE) increases even more than the liver weight at corresponding concentrations, but only in the males. Depletion of testosterone through castration or destruction of the pituitary gland or hypothalamus, are the only other ways to experimentally induce corresponding increases in BuChE. Plasma BuChE activity increase was found to be a common reaction after exposure to TCE, perchloroethylene, chloroform, methylene chloride and carbon tetrachloride and also after exposure to ethanol. Other solvents such as toluene, xylene, benzene and 1,1,1-trichloroethane had little or no effect on BuChE activity. Normal and castrated male mice were continuously exposed for one month to 150 p.p.m. TCE. The increase in BuChE activity after the exposure was of the same magnitude as the increase seen after castration. BuChE activity in castrated males was not further increased by TCE exposure. Administration of testosterone with osmotic minipumps for 13 days almost restored the normal testosterone and BuChE levels in castrates. The effect of TCE exposure on BuChE activity in these animals was the same as on normal males. Testosterone levels were not influenced by the TCE exposure in normal males or in castrates given testosterone. No sex hormone binding globulins (SHBG) could be detected in the mice. BuChE activity changes induced through solvent exposure are therefore neither directly nor indirectly (through SHBG) due to effects on testosterone. The results from these animal experiments do not support the epidemiological findings of decreased testosterone levels in humans exposed to solvents.     

Effects of long-term occupational solvent exposure on contrast sensitivity and performance in visual search

Sensitive and easily applicable screening tests are greatly needed for the early detection of nervous system dysfunction in people working with neurotoxic substances. Previous studies have shown that long-term solvent exposure may cause deficits in visual perception. We, therefore, studied the effects of long-term occupational solvent exposure and chronic encephalopathy on performance in three vision tests novel in the present context. Two visual search tasks were used: the letter search test measured the speed of finding a letter in an array of numerals, and the pop-out search test required the observer to detect the presence or absence of a tilted line segment in an array of vertical line segments. With the letter contrast sensitivity test we measured the contrast threshold for the identification of band-pass filtered letters. Before testing, comprehensive eye examination was carried out to reveal any structural or functional abnormality and to ensure correct refraction. The patients had healthy eyes, 2 out of 14 had reduced contrast sensitivity (Vistech) and 5 out of 14 had deficits in colour vision (FM 100). In both visual search tasks, the patients were statistically highly significantly (p < 0.001) slower than the age-matched control observers. Instead, in the contrast sensitivity test, the difference between the patient and the control group was small relative to normal variability although still statistically significant (p < 0.05). The results suggest that visual search tests can be useful in evaluating and characterising the effects of long-term solvent exposure on visual perception. Because our patients’ letter contrast sensitivity was only moderately deteriorated, it seems that the observed defect of visual search cannot be explained by deteriorated letter identification alone, although it can be a contributory factor. Rather, the finding suggests that the speed by which visual information is transmitted and/or processed in the central visual system has become considerably slower.     

Nitrite content and antioxidant enzyme levels in the blood of schizophrenia patients

RATIONALE: Recent studies have suggested augmentation in the inflammatory response as well as involvement of nitric oxide (NO) in mood disorders. Polymorphonuclear leukocytes (PMN), NO and free radicals have been associated with inflammatory response; however, the status of NO in the PMN has not been investigated so far in schizophrenia patients. OBJECTIVES: The present study was undertaken to investigate levels of nitrite (a metabolite of NO), malonaldehyde (MDA, lipid peroxidation product) and antioxidant enzymes such as superoxide dismutase (SOD), catalase and glutathione peroxidase (Gpx) in the PMN of schizophrenia patients. METHODS: Patients with schizophrenia (n=62) were diagnosed according to DSM-IV and were free of anti-psychotic medications/ECT for at least 3 months. Mean age of the patients was 29.06+/-1.17 years, with a male to female ratio of 4:1, and mean duration of illness was 3.7+/-0.6 years. The control group consisted of 82 healthy subjects with a mean age of 37.0+/-1.26 and a male to female ratio of 5:1. PMN were isolated from the blood. Nitrite, MDA and antioxidant enzymes were estimated by standard biochemical techniques in the PMN of normal healthy controls and schizophrenia patients. Platelet and plasma nitrite levels were also estimated in controls and schizophrenia patients. RESULTS: Nitrite content in the PMN was reduced to 68%, while plasma and platelet nitrite content in schizophrenia patients was not significantly changed in comparison to controls. Malonaldehyde (MDA) content in PMN was significantly augmented in schizophrenia patients but activity of SOD, catalase and Gpx remain unaltered. CONCLUSION: Results obtained indicate a significant decrease in NO synthesis and an increase in MDA in the PMN of schizophrenia patients, while antioxidant enzyme activities were not altered in the PMN of schizophrenia patients. This suggests that the decrease in PMN NO synthesis by PMN might lead to oxidative stress in schizophrenia patients.     

Effects of waterborne acephate exposure on antioxidant responses and acetylcholinesterase activities in Synechogobius hasta

The present study was conducted to determine the 24, 48, 72, and 96‐h median lethal concentration (LC50) of acephate and investigate the antioxidant response and acetylcholinesterase (AChE) activities in liver, gill, and spleen of Synechogobius hasta exposed to 0 (control), 5, and 10 mg/L acephate, at the fixed interval time of 24, 48, 72, and 96 h, respectively. LC50 value was 60.83 mg/L at 24 h, 51.36 mg/L at 48 h, 47.07 mg/L at 72 h and 40.13 mg/L at 96 h, respectively. Dismutase (SOD), catalase (CAT), AChE activities, and malondialdehyde (MDA) levels in these tissues for the control remained stable over the exposure period. However, for the two tested groups, tissue‐, dose‐, and time‐dependent responses of these parameters were observed in S. hasta. In general, hepatic SOD and CAT activities were significantly inhibited at 24 h, activated, and increased at 48 h, but again inhibited from 48 to 96 h in fish exposed to the two tested concentrations. Hepatic MDA levels of fish for the two tested concentration peaked at 48 h, significantly higher than the control. Hepatic AChE activity was inhibited at 24 h, peaked at 48 h, and then declined at 72 h for the two tested groups. For gills, the highest SOD and CAT activities for the two tested groups were observed at 48 h, higher than the control. AChE activities for the two tested groups were significantly inhibited at 24 h, but activated at 48 h. At 96 h, AChE activities among the treatments showed no significant differences. Gill MDA levels at 48 h for the tested groups were significantly higher than the control, but showed no significant differences at 24 and 72 h among the treatments. In spleen, SOD and CAT activities at 48 h for the two tested groups were significantly higher than those in the control, but at 96 h the vice versa was true. Spleenic AChE activities and MDA levels for the two tested groups were inhibited at 24 h, activated at 48 h, and then were again inhibited at 72 h. Based on these observations earlier, the results obtained in our study will have important toxicological implications for waterborne acephate pollution and, meantime, provide the basis for the effective risk assessment of acephate in water environment and appropriate safety recommendations for fish. © 2011 Wiley Periodicals, Inc. Environ Toxicol 2013.     

Effect of perfluorooctanesulfonate exposure on steroid hormone levels and steroidogenic enzyme activities in juvenile Silurana tropicalis

The impact of the perfluoro‐chemical, perfluorooctanesulfonate (PFOS), on gonadal steroidogenesis during sexual differentiation in Silurana tropicalis was examined because of its ubiquity in the environment, bioaccumulative nature and potential to disturb endocrine activity. A partial life cycle study exposing S. tropicalis to varying concentrations of PFOS 0.06, 0.13, 0.25, 0.50 and 1.0 mg PFOS/L [nominal]) was conducted. Gonad and plasma samples were collected from juvenile control specimens and organisms exposed to PFOS from early embryo through 150 days post‐metamorphosis. Gonad CYP17, aromatase and 5α‐reductase activities were measured. Plasma estradiol, testosterone, dihydrotestosterone (DHT) and gonadal testosterone were measured in both males and females. Increased plasma DHT and gonadal testosterone were found in PFOS‐treated juvenile male S. tropicalis compared to controls. Decreased plasma estradiol, but not testosterone, was detected in PFOS‐treated female S. tropicalis compared to controls. Plasma DHT was not detected and an increase in gonadal testosterone was detected in PFOS‐treated female frogs. Female S. tropicalis exposed to PFOS exhibited a concentration‐related decrease in the mean aromatase activity, but not 5α‐reductase. PFOS exposure in male frogs induced a concentration‐related increase in 5α‐reductase activity, but did not alter aromatase activity compared to control frogs. A concentration‐related increase in CYP 17,20‐lyase activity, but not 17‐hydroxylase activity, was found in both female and male S. tropicalis exposed to PFOS.     

Effects of propylthiouracil treatment on antioxidant activities in blood of toxic multinodular goiter patients

Erythrocyte, serum and plasma antioxidant activities and the effects of propylthiouracil (PTU) treatment on these activities were studied in patients with toxic multinodular goiter. The activities of the erythrocyte antioxidant enzymes (glucose-6-phosphate dehydrogenase, catalase, Cu/Zn-superoxide dismutase, selenium (Se)-dependent glutathione peroxidase and glutathione reductase) and the levels of erythrocyte Se, serum ceruloplasmin and plasma malondialdehyde were significantly higher while serum vitamin E, plasma vitamin C and plasma Se were lower in hyperthyroid patients. PTU treatment, not for 1 but for 3 months caused a partial reversal of antioxidant activities to euthyroid levels. It is suggested that alterations in blood antioxidant activities following PTU treatment might be due to the antioxidant and/or antithyroid effect of this drug.     

Effects of long-term Ailanthus altissima extract supplementation on fear,cognition and brain antioxidant levels

IntroductionAilanthus altissima is an indigenous plant known for various remedial properties. The present study aimed to evaluate the neuroprotective potential of methanolic extract Ailanthus altissima (AA) bark as current scientific trend is searching plant for neurodegenerative diseases, worldwide.MethodologyIn in-vitro experiments, the AA was analyzed for phenols, flavonoids, antioxidative and cholinesterase inhibitory properties with subsequent detailed characterization for secondary metabolites. The in-vivo neurological effects were evaluated in rats through behavioral assessment for anxiety and memory after chronic administration (28 days) of 50–200 mg/kg of AA. At the end of behavior studies, isolated brains were biochemically tested to determine antioxidant enzyme activity.ResultsAA was found rich in phenols/flavonoids and active in radical scavenging with the presence of 13 secondary metabolites in UHPLC-MS analysis. The AA yielded anxiolytic effects dose-dependently in the open field, light/dark and elevated-plus maze tests as animals significantly (P < 0.05 vs control group) preferred open arena, illuminated zone and exposed arms of maze. Similarly, the animals treated with AA showed significant (P < 0.05 vs amnesic group) increase in spontaneous alternation, discrimination index in y-maze, novel object recognition tests. Further, AA.Cr treated rats showed noticeably shorter escape latencies in Morris water maze tests.In biochemical analysis, the dissected brains AA treated rats showed reduced levels of AChE and malondialdehyde with increased levels of first-line antioxidant enzymes i.e. glutathione peroxidase and superoxide dismutase. These observed biological effects might be attributed to phenols and flavonoids constituents owned by AA. -The in-silico studies showed thatconessine and lophirone J phytocompounds have good blood–brain barrier permeability and interaction with AChE.ConclusionThe outcomes of this study validate that bark of Ailanthus altissima might work as a source of bioactive phytochemicals of neuroprotective potential.     

Effects of ethanol on catecholamine levels and related enzyme activities in different brain regions of rats

The effects of ethanol on the contents of norepinephrine (NE) and dopamine (DA) and the activities of related enzymes in the various regions of rat brains with different doses and mode of administration of ethanol were investigated. In acute ethanol intoxication, steady-state levels of NE were not altered. Continuous ethanol intoxication, however, significantly reduced NE contents and tended to decrease the activity of dopamine-beta-hydroxylase in the hippocampus. The decrease in NE contents became more significant during ethanol withdrawal, especially in the medulla oblongata and the striatum. DA contents were increased in the brain-stem region in all ethanol-treated rats. The increase in DA contents correlated with the increase in tyrosine hydroxylase activity. The present data suggest that the dopaminergic system may contribute to the development of physical dependence on ethanol.     

Effects of Selol 5% supplementation on tissue antioxidant enzyme levels and peroxidation marker in healthy mice

Background

Selenium (Se) is an essential micronutrient for animals and humans used in the prevention or treatment of cancer. Selol is a mixture of selenitetriglycerides, containing Se(IV). It does not exhibit mutagenic activity and is less toxic than inorganic sodium selenite containing Se(IV). The antioxidant properties of the Selol were demonstrated using the blood of healthy animals. The aim of the study was to evaluate Selol as a Se supplement by determining the effect of its administration on the Se level and the antioxidant status in the tissues.

辛伐他汀对压力超负荷心肌肥厚大鼠心肌内源性抗氧化酶及血管紧张素转化酶活性的影响

目的:研究辛伐他汀对压力超负荷心肌肥厚大鼠心肌内源性抗氧化酶及血管紧张素转化酶活性的影响.方法:在左右肾动脉之间部分结扎腹主动脉诱导左心室肥厚(LVH).6周后,大鼠ig辛伐他汀1.8和3.6mg·kg~(-1)·d~(-1)8周,然后测定左心室组织内源性抗氧化酶和血管紧张素转化酶(ACE)活性以及脂质过氧化物(TBARS)含量.结果:LVH组(n=8)大鼠左心室组织血管紧张素Ⅱ(Ang Ⅱ)和TBARS含量、ACE及Cu,Zn-超氧化物歧化酶(SOD)活性分别比假手术组(n=7)大鼠增加163％、90％、130％和33％(P<0.01),而过氧化氢酶(CAT)和谷胱甘肽过氧化物酶(GSH-Px)的活性则分别比假手术组大鼠减少29％和23％(P<0.01).3.6mg·kg~(-1)·d~(-1)辛代他汀处理的大鼠(n=9)Ang Ⅱ、TBARS含量及ACE活性比LVH组大鼠分别减少30％,37％和51％,而CAT和GSH-Px的活性比LVH组大鼠分别增加32％和22％(P<0.01).辛伐他汀对SOD活性没有明显的影响.结论:心肌内抗氧化酶活性的变化与压力超负荷性心肌肥厚的形成和发展有关.辛伐他汀对大鼠心肌肥厚的抑制作用可能与其抗氧化作用有关.     

Serum antioxidant enzyme activities and oxidative stress parameters as possible biomarkers of exposure in veal calves illegally treated with dexamethasone

Low doses of the synthetic glucocorticoid dexamethasone (DEX) are often illegally used, alone or in association with steroids and β-agonists, to improve meat performances in cattle. As it is known that oestrogens and β-agonists may generate reactive oxygen species (ROS) and induce oxidative stress, the effects of illicit DEX protocols on the antioxidant status and oxidative stress parameters were measured in veal calves.Ten cross-bred male veal calves were given DEX (0.4 mg/day administered per os, for 23 days or 2 mg pro capite, injected intramuscularly on days 14 and 21 after the beginning of the oral DEX administration). Five further animals were used as controls. Blood samples were withdrawn before (T₀), and 4 (T₁), 10 (T₂), 14 (T₃), 21 (T₄) and 28 (T₅) days. Antioxidant enzyme activities (AOEs), the serum antioxidant capacity (SAC) and ROS were measured in sera.Calves orally treated showed a significant increase of both glutathione peroxidase isoforms (P < 0.05) and SAC (P < 0.05), too.Antioxidant enzymes have already been used as biomarkers (BMs) of response, measured in target or in surrogate tissues. Our results suggest glutathione peroxidase and SAC as possible BMs of illicit oral low-dose administration of DEX in cattle.     

不同浓度胎牛血清对骨髓基质细胞产生细胞因子水平影响的研究

目的通过比较使用不同浓度胎牛血清(FBS)培养的骨髓基质细胞(BMSCs)产生某些细胞因子的量,揭示FBS对BMSCs产生细胞因子是否有影响。方法采用密度梯度离心法分离骨髓单一核细胞,分别使用10%和20%FBS通过贴壁法培养BMSCs,收集传3代后又培养72h的BMSCs及培养上清,用流式细胞仪鉴定细胞表面标志并用酶联免疫吸附试验(ELISA)法检测上清液中白细胞介素(IL)-7、IL-8和干细胞因子(SCF)的水平。结果90%以上细胞表面抗原高表达CD29,而CD34、CD45及HLA-DR表达阴性,即BMSCs纯度在90%以上;两组BMSCs培养上清液中IL-7、IL-8和SCF的水平差异无统计学意义(P>0.05)。结论胎牛血清对BM-SCs产生细胞因子没有影响。     

Topiramate and vitamin e modulate antioxidant enzyme activities, nitric oxide and lipid peroxidation levels in pentylenetetrazol-induced nephrotoxicity in rats

Previous studies have shown that generation of free radicals is increased following pentylenetetrazol kindling, due to increased cytosolic Ca2+ concentrations. Topiramate, a voltage-gated calcium channel inhibitor, has an evident effect in the treatment of childhood epilepsy; however, topiramate may cause nephrotoxicity. We investigated the effects of topiramate and vitamin E administration on pentylenetetrazol-induced nephrotoxicity in rats by evaluation of lipid peroxidation, nitric oxide, glutathione peroxidase, catalase and superoxide dismutase values. Forty male Wistar rats were randomly divided into five equal groups. Group 1 was used as control and group II received a single dose of pentylenetetrazol. Fifty and 100 mg/kg topiramate daily were intragastrically administered to rats in groups III and IV for 7 days, respectively. Intragastric 100 mg topiramate (daily for 7 days) and intraperitoneal vitamin E (150 mg/kg, daily for 3 days) combination were given to animals in group V before a single-dose pentylenetetrazol administration. Serum and kidney samples were taken after 3 hr of pentylenetetrazol administration. Pentylenetetrazol resulted in a significant increase in nitric oxide levels of serum and kidney, and lipid peroxidation levels of kidney although superoxide dismutase and catalase activities in the kidney was reduced by pentylenetetrazol administration. The lipid peroxidation levels in serum and kidneys and the nitric oxide levels in kidneys of groups III, IV and V were decreased by topiramate although the superoxide dismutase and catalase activities in the kidneys were increased. Lipid peroxidation and nitric oxide levels were reduced by the topiramate and vitamin E combination compared to only topiramate. Glutathione peroxidase activity was not affect by pentylenetetrazol, topiramate and vitamin E administrations. In conclusion, topiramate and vitamin E have protective effects on pentylenetetrazol-induced nephrotoxicity by inhibition of free radicals and by support of the antioxidant redox system.     

Effects of dietary vitamin E,C and soybean oil supplementation on antioxidant enzyme activities in liver and muscles of rats

The effect of elevated levels of dietary vitamin E, C and a combination of vitamin E and C (E & C) with soybean oil on activities of antioxidant (AOE) enzymes important in the protection against lipid peroxidation was studied in male rats fed with vitamin C (12 mg/g), vitamin E (3.68 mg/g) or E & C (3.68 mg/kg + 12 mg/g) supplemented diets for 28 days. Catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR) activity in liver, pectoralis major (PM) and sartorius (S) muscles was increased significantly in rats fed with dietary vitamin C, E separately, and vitamin C & E combination, except, superoxide dismutase (SOD), which showed no alterations. These results clearly indicated that vitamin E & C separately and E & C together increased AOE activity in liver, PM and S muscle of rats. However, vitamin E and C combination enhanced AOE activity more significantly and our findings suggest the possible role of vitamin C & E and their combination in reducing the risk of chronic diseases related to oxidative stress.     

Bisphenol A levels in blood depend on age and exposure

We present two approaches to estimate blood concentrations of Bisphenol A (BPA). Simple kinetic principles were applied to calculate steady state plasma concentrations. A physiologically based model was used to simulate the blood concentration time profile in several age groups exploring the influence of not yet fully developed metabolic capacity on the blood concentrations in the newborn.Both approaches gave concordant results and are in excellent agreement with experimental results [Völkel, W., Colnot, T., Csanady, G.A., Filser, J.G., Dekant, W., 2002. Metabolism and kinetics of bisphenol A in humans at low doses following oral administration. Chem. Res. Toxicol. 15, 1281–1287]. The predictions also agree with published results obtained with a different physiologically based model.According to model simulations, BPA is present in the blood of the normal population at concentrations several orders of magnitude lower than most measurements reported in the literature. At the same external exposure level, the newborn is predicted to have 3 times greater blood concentration than the adult. This is due to the not yet fully developed glucuronidation activity in the newborn, not fully compensated by the unimpaired sulfation pathway. For the highest measured external BPA exposure, the predicted blood concentrations of 2.6 pg/ml (steady state concentration) and 8.2 pg/ml (peak concentration) in the adult are lower than the in vitro concentrations at which inhibiting adiponectin release from human adipocytes and stimulation of β-cell production and secretion were observed.     

Effects of long-term exposure to environmental levels of polychlorinated biphenyls on pharmacokinetics of pentobarbital in rats.

The pharmacokinetics of pentobarbital, 30mg/kg iv, were studied in untreated rats and rats pretreated with 1,5, and 25 ppm of polychlorinated biphenyls in food for up to 140 days. Environmental contaminants may contribute to variations in metabolic rates of drugs by causing enzyme induction. The objective of this work was to quantitate the effects of environmental levels of the contaminant and enzyme inducer, a polychlorinated biphenyl, on the pharmacokinetics of pentobarbital, a drug whose primary elimination route is liver metabolism. The pharmacokinetics of pentobarbital in rats could be fit to a biexponential equation of the type Cp = Ae-alpha t+ Be-beta t. After 35 days of pretreatment, only the 25-ppm-treated rats showed any significant acceleration of pentobarbital elimination. At the 70- and 140-day samplings, both the 5- and 25-ppm pretreatments showed significant acceleration of pentobarbital elimination. There were no significant effects on A, alpha, B, and Vd for any pretreatment. The beta-values for the 25-ppm-pretreated rats reached a constant value from the 35-day pretreatment period onward. A calculation of total body clearance suggested that pentobarbital elimination in those rats had approached portal blood flow rate-limited metabolism.     

Effects of chitosan on serum cytokine levels in elderly subjects

This study was done to evaluate the immune enhancing activity of health function food, chitosan by clinical study. To evaluate the effect of chitosan on serum cytokine levels in elderly adults, 5.1 g/day of chitosan was administrated to volunteers (age range 74 approximately 86, mean 80 +/- 3 year old) for 8 weeks. This study was IRB approved and all patients gave informed consent prior to examination. The clinical study showed that the increase of IL-2, IL-12, and TNF-alpha production were a little greater in chitosan administered group as in the control group but there were no significant differences. In the safety study with blood biochemical test, it has been shown that all safety parameters in liver were in normal ranges. Also there were no significant changes in the values of the electrolytes, blood lipids profiles, glucose levels and leucocytes number. With these results we have not found any safety problems after the administration of chitosan for 8 weeks. In this study, there was a tendency of immune enhancing effect of chitosan at the experimental dose, which is generally used. More intense clinical study will be needed to confirm statistical significance.     

Changes in antioxidant enzymes in humans with long-term exposure to pesticides

Different pesticides, including organophosphates (OPs), have been reported to induce oxidative stress due to generation of free radicals and alteration in antioxidant defence mechanisms. In this study, a cohort of 81 intensive agriculture workers (pesticide sprayers) was assessed twice during the course of a spraying season for changes in erythrocyte antioxidant enzymes. Acetylcholinesterase (AChE) was used as a reference biomarker. Sprayers presented lower levels of superoxide dismutase (SOD) and glutathione reductase (GR) as compared to controls independently of age, BMI, smoking habit or alcohol consumption. A positive correlation between SOD and AChE was observed at the high exposure period. Those individuals with a decrease in AChE greater than 15% exhibited lower SOD and catalase (CAT) activities at the same period. Glutathione peroxidase (GPx) and glucose-6-phosphate dehydrogenase (G6PDH) remained unaffected in the exposed population. Paraoxonase (PON1) polymorphism influenced erythrocyte CAT and GR, as subjects with the R allele presented lower CAT and higher GR levels. Whether or not the decreased enzyme activities found in this study are linked to the adverse health effects related to chronic pesticide toxicity (in which oxidative damage plays a pathophysiological role, such as cancer or neurodegenerative disorders) is an attractive hypothesis that warrants further investigation.