The situation of chlorpyrifos in Mexico: a case study in environmental samples and aquatic organisms.

Chlorpyrifos (CPF) is one of the most commonly used organophosphate pesticides. Because CPF was described as a toxic compound without safe levels of exposure for children, certain countries in Latin America and the European Union have banned or restricted its use; however, in Mexico it is used very frequently. The aim of this study was to describe the current situation of CPF in Mexico, as well as its use, commercialization, and presence in soil, water, and aquatic organisms in an agricultural region of Mexico.

Hematological indices as indicators of inflammation induced by exposure to pesticides.

Pesticide toxicity, both acute and chronic, is a global public health concern. Pesticides are involved in abnormal inflammatory responses by interfering with the normal physiology and metabolic status of cells. In this regard, inflammatory indices aggregate index of systemic inflammation (AISI), monocyte-to-high-density lipoprotein ratio, monocyte-to-lymphocyte ratio (MLR), neutrophil-to-lymphocyte platelet ratio (NLPR), neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, systemic immune inflammation index, and systemic inflammation response index (SIRI) have been used as predictive markers of inflammatory status in several diseases and also in acute poisoning events.

The Relationship between Cancer and Paraoxonase 1.

Extensive research has been carried out to understand and elucidate the mechanisms of paraoxonase 1 (PON1) in the development of diseases including cancer, cardiovascular diseases, neurological diseases, and inflammatory diseases. This review focuses on the relationship between PON1 and cancer. The data suggest that PON1, oxidative stress, chronic inflammation, and cancer are closely linked.

Methylation patterns of the and genes in an indigenous population exposed to pesticides.

The locus includes the and genes and is functionally relevant in the regulation of both cell proliferation and senescence. Studies have reported modifications of DNA methylation in this locus by exposure to environmental contaminants including pesticides; however, until now, specific methylation profiles have not been reported in genetically conserved populations exposed to occupational pesticides. The aim of this study was to determine the methylation profiles of the and genes in a genetically conserved population exposed to pesticides.

Organophosphorus pesticide exposure biomarkers in a Mexican population.

The organophosphate (OP) pesticides are neurotoxic compounds widely used around the world. Evaluation of OP exposure in human studies is important for enabling adequate data analyses and drawing accurate conclusions. The aim of this study was to analyze OP exposure biomarkers and their relationships in a Mexican population with different exposure levels.

Toxicokinetics of temephos after oral administration to adult male rats.

Temephos (Tem) is the larvicide of choice to control mosquito transmission of dengue, Zika, and chikungunya. The toxicokinetic and toxicological information of temephos is very limited. The aim of this work was to determine the toxicokinetics and dosimetry of temephos and its metabolites.

Environmental and socio-cultural impacts on global DNA methylation in the indigenous Huichol population of Nayarit, Mexico.

Alterations of global DNA methylation have been evaluated in several studies worldwide; however, Long Interspersed Nuclear Elements-1 (LINE-1) methylation in genetically conserved populations such as indigenous communities have not, to our knowledge, been reported. The aim of this study was to evaluate the relationship between LINE-1 methylation patterns and factors such as pesticide exposure and socio-cultural characteristics in the Indigenous Huichol Population of Nayarit, Mexico. A cross-sectional study was conducted in 140 Huichol indigenous individuals.

Relationship between butyrylcholinesterase activity and lipid parameters in workers occupationally exposed to pesticides.

Exposure to organophosphate pesticides (OP) has been associated with the inhibition of cholinesterase enzymatic activity, such as butyrylcholinesterase (BuChE). Changes in BuChE activity have been associated with obesity, diabetes, hyperthyroidism, and metabolic syndrome. However, few studies have evaluated the effects of pesticides on both BuChE and lipid parameters.

Phenotypes and concentration of PON1 in cardiovascular disease: The role of nutrient intake.

Background And Aims: Paraoxonase 1 (PON1) is considered to play a crucial role as an anti-atherosclerotic factor. The PON1 activity is affected by genetic polymorphisms, environmental factors, age, sex, lifestyle, pharmaceutical drugs, and dietary factors. The aim of this study was to evaluate the association between macro- and micronutrients as well as PON1 concentration and activities in patients with cardiovascular diseases (CVD), cardiovascular risk factors but no CVD (CRF), and in healthy controls (control group).

In vitro inhibition of human red blood cell acetylcholinesterase (AChE) by temephos-oxidized products.

Temephos (Tem) is an organophosphorus pesticide widely used to kill and prevent the growth of the main vectors for the transmission of dengue, zika, and chikungunya viruses. In chlorinated water, Tem is oxidized to its dioxon-sulfoxide (Tem-dox-SO), dioxon-sulfone (Tem-dox-SO), and sulfoxide (Tem-SO) derivatives; however, these compounds are not commercially available to be used as standards and in toxicological studies. In the present study, we synthesized and characterized the Tem-oxidation products and the compound 4,4'-sulfinyldiphenol.

Pesticide Exposure Modifies DNA Methylation of Coding Region of , an Antisense Sequence of in a Mexican Population.

The influence of pesticide exposure in alteration of DNA methylation patterns of specific genes is still limited, specifically in natural antisense transcripts (NAT), such as the gene. The aim of this study was to determine the methylation of the gene in mestizo and indigenous populations as well as its relationship with internal (age, sex, and body mass index) and external factors (pesticide exposure and micronutrient intake). A cross-sectional study was conducted including 91 mestizo individuals without occupational exposure to pesticides, 164 mestizo urban sprayers and 189 indigenous persons without occupational exposure to pesticides.

Relationship between internal and external factors and the activity of PON1.

Paraoxonase 1 (PON1) is an A-esterase calcium-dependent enzyme that is associated with high-density lipoprotein (HDL) and capable of hydrolyzing a wide variety of substrates, including organophosphate (OP) pesticides. The PON1 phenotype can be modulated by multiple internal and external factors, thereby affecting the catalytic capacity of the enzyme. The aim of this study was to evaluate factors that could modulate PON1 activity in a sample occupationally exposed to pesticides.

PON1 concentration and high-density lipoprotein characteristics as cardiovascular biomarkers.

Introduction: Serum paraoxonase 1 (PON1) is now known to be related to cardiovascular diseases (CVD). The aim of this study was to determine the relationship between PON1 concentration and high-density lipoprotein (HDL) subclasses in patients with proven CVD, cardiovascular risk factors but no CVD (CRF), and in healthy controls (control group).

Material And Methods: A case-control study was carried out with 69 volunteers from the Mexican Institute of Social Security, Mexico.

Modified CDKN2B (p15) and CDKN2A (p16) DNA methylation profiles in urban pesticide applicators.

Gene-specific changes in DNA methylation by pesticides in occupationally exposed populations have not been studied extensively. Of particular concern are changes in the methylation profile of tumor-suppressor, such as CDKN2B and CDKN2A, genes involved in oncogenesis. The aim of this study was to evaluate the methylation profiles of CDKN2B and CDKN2A genes in urban pesticide applicators and their relationship with occupational exposure to pesticides.

β-Glucuronidase and Its Relationship With Clinical Parameters and Biomarkers of Pesticide Exposure.

Objective: This study determined β-glucuronidase activity and its relationship with clinical, biochemical, and pesticide-exposure biomarkers in workers occupationally exposed mainly to OP insecticides.

Methods: A cross-sectional study was conducted in pesticide applicators. Three study groups were established: reference group, moderate-exposure group, and high-exposure group.

Micronucleus frequency is correlated with antioxidant enzyme levels in workers occupationally exposed to pesticides.

Oxidative stress can cause DNA damage leading to nuclear anomalies such as micronuclei (MN). Antioxidant enzymes involved in protection against intracellular oxidative stress include glutathione peroxidase (GPx), glutathione reductase (GR), superoxide dismutase (SOD), and catalase (CAT). Pesticide exposure induces oxidative stress and alters antioxidant defense mechanisms, including detoxification and scavenger enzymes.

Relationship between LINE-1 methylation pattern and pesticide exposure in urban sprayers.

Recently a relationship has been reported between pesticide exposure and changes in global DNA methylation patterns. Urban sprayers are a particularly vulnerable population because of the high risk of pesticide exposure that their work implies. Therefore, the aim of this study was to estimate the changes in the Long Interspersed Nucleotide Element (LINE-1) in urban sprayers and its relationship with pesticide exposure.

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

The indiscriminate use of pesticides in agriculture and public health campaigns has been associated with an increase of oxidative stress and DNA damage, resulting in health outcomes. Some defense mechanisms against free radical-induced oxidative damage include the antioxidant enzyme systems. The aim of this study was to determine the levels of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), and the relationship of antioxidant enzyme levels with DNA damage among sprayers (workers) occupationally exposed to pesticides.

Downregulation of human paraoxonase 1 (PON1) by organophosphate pesticides in HepG2 cells.

Paraoxonase 1 (PON1) is a calcium-dependent esterase synthesized primarily in the liver and secreted into the plasma where it is associated with high-density lipoproteins (HDL). PON1 hydrolyzes and detoxifies some toxic metabolites of organophosphorus compounds (OPs) such as methyl parathion and chlorpyrifos. Thus, PON1 activity and expression levels are important for determining susceptibility against OPs poisoning.

Paraoxonase 1 and its relationship with pesticide biomarkers in indigenous Mexican farmworkers.

Objective: Biomarkers of pesticide toxicity and paraoxonase 1 (PON1) phenotype and genotypes were evaluated in indigenous Mexican farmworkers exposed mainly to organophosphate (OP) pesticides.

Methods: Acetylcholinesterase, butyrylcholinesterase, and PON1 activities--arylesterase and CMPAase activities--were evaluated spectrophotometrically. PON1 55 and 192 polymorphisms were determined by real-time polymerase chain reaction.