title: Changes in antioxidant enzymes in humans with long-term exposure to pesticides.
abstract: 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.
authors.affiliation: Department of Legal Medicine and Toxicology, University of Granada School of Medicine, Avda. Madrid, 11. 18071-Granada, Spain.
authors.forename: Olga
authors.initials: O
authors.lastname: López
authors.forename: Antonio F
authors.initials: AF
authors.lastname: Hernández
authors.forename: Lourdes
authors.initials: L
authors.lastname: Rodrigo
authors.forename: Fernando
authors.initials: F
authors.lastname: Gil
authors.forename: Gloria
authors.initials: G
authors.lastname: Pena
authors.forename: José Luis
authors.initials: JL
authors.lastname: Serrano
authors.forename: Tesifón
authors.initials: T
authors.lastname: Parrón
authors.forename: Enrique
authors.initials: E
authors.lastname: Villanueva
authors.forename: Antonio
authors.initials: A
authors.lastname: Pla
mesh_terms: D000110:Acetylcholinesterase / Q000097:blood; D000328:Adult; D000382:Agricultural Workers' Diseases / Q000201:enzymology; D000975:Antioxidants / Q000378:metabolism*; D043303:Aryldialkylphosphatase / Q000235:genetics; D002374:Catalase / Q000097:blood; D004798:Enzymes / Q000097:blood*; D004912:Erythrocytes / Q000201:enzymology; D005260:Female; D005954:Glucosephosphate Dehydrogenase / Q000097:blood; D005979:Glutathione Peroxidase / Q000097:blood; D006801:Humans; D008297:Male; D016273:Occupational Exposure / Q000009:adverse effects*; D010755:Organophosphates / Q000009:adverse effects; D010575:Pesticides / Q000009:adverse effects*; D011110:Polymorphism, Genetic / Q000235:genetics; D013030:Spain; D013482:Superoxide Dismutase / Q000097:blood
chemical_list: D000975:Antioxidants; D004798:Enzymes; D010755:Organophosphates; D010575:Pesticides; D005954:Glucosephosphate Dehydrogenase; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D000110:Acetylcholinesterase; D043303:Aryldialkylphosphatase; C468406:PON1 protein, human