Acute toxicity of veterinary and agricultural formulations of organophosphates dichlorvos and diazinon in chicks

Correlation between acute brain injury and brain metabonomics in dichlorvos-poisoned broilers

Dichlorvos (DDVP) is an insecticide with neurotoxicity that is widely used in agricultural production and life. However, the effects of acute DDVP poisoning on brain tissue remain underinvestigated. The purpose of this study was to evaluate the differences within 15 min-6 h in plasma biochemical indexes, brain histology and metabolites among three groups of commercial broilers orally administered different dosages of DDVP one time: (1) high-dose group (11.3 mg/kg), (2) low-dose group (2.48 mg/kg) and (3) control group (0 mg/kg). The results of biochemical indexes showed that acute DDVP poisoning could cause hyperglycemia and oxidative stress in poisoned broilers. Histological examination showed that DDVP could induce brain edema, abnormal expression of glial fibrillary acidic protein (GFAP) and neuronal mitochondrial damage in broilers. Whole-brain metabolism showed that DDVP could significantly change the secretion of neurotransmitters, energy metabolism, amino acid metabolism and nucleotide metabolism. Correlation analysis showed that metabolites such as hypoxanthine, acetylcarnitine and glucose 6-phosphate were significantly correlated with blood glucose, biomarkers of oxidative stress and brain injury pathology. The results of this study provide new insights into the molecular mechanism of brain tissue responses to acute DDVP exposure in broilers and deliver important information for clinical research on neurodegenerative diseases caused by acute DDVP poisoning.

Emerging Technologies for Degradation of Dichlorvos: A Review

Dichlorvos (O,O-dimethyl O-(2,2-dichlorovinyl)phosphate, DDVP) is a widely acknowledged broad-spectrum organophosphorus insecticide and acaracide. This pesticide has been used for more than four decades and is still in strong demand in many developing countries. Extensive application of DDVP in agriculture has caused severe hazardous impacts on living systems. The International Agency for Research on Cancer of the World Health Organization considered DDVP among the list of 2B carcinogens, which means a certain extent of cancer risk. Hence, removing DDVP from the environment has attracted worldwide attention. Many studies have tested the removal of DDVP using different kinds of physicochemical methods including gas phase surface discharge plasma, physical adsorption, hydrodynamic cavitation, and nanoparticles. Compared to physicochemical methods, microbial degradation is regarded as an environmentally friendly approach to solve several environmental issues caused by pesticides. Till now, several DDVP-degrading microbes have been isolated and reported, including but not limited to Cunninghamella, Fusarium, Talaromyces, Aspergillus, Penicillium, Ochrobium, Pseudomonas, Bacillus, and Trichoderma. Moreover, the possible degradation pathways of DDVP and the transformation of several metabolites have been fully explored. In addition, there are a few studies on DDVP-degrading enzymes and the corresponding genes in microorganisms. However, further research relevant to molecular biology and genetics are still needed to explore the bioremediation of DDVP. This review summarizes the latest development in DDVP degradation and provides reasonable and scientific advice for pesticide removal in contaminated environments.

Evaluating Hemolytic and Photo Hemolytic Potential of Organophosphorus by In Vitro Method as an Alternative Tool Using Human Erythrocytes

AIMS

The present study aims to determine the phototoxic and haemolytic activity of organophosphorus. The use of alternative in vitro assays with human erythrocytes is suggested to predict the polluting effect of these products on health.

METHODOLOGY

Human erythrocytes from Toluca Blood Bank were used. Sodium dodecyl sulfate was employed as a positive control. Additionally, the haemolysis percentage of three organophosphate (Acetate, Chlorpyrifos, Malathion, Methamidophos, Methyl Parathion) induced photo haemolysis formulated with surfactants on a concentration of 2 x 109 erythrocytes were evaluated. Finally, the products were classified as irritant or phototoxic.

RESULTS

Results showed that the HC50 red blood cells were similar for each organophosphate (Malathion and Methamidophos) indicating very irritant action with ratio classification (L/D) of 0.041 and 0.053, respectively. On the other hand, Chlorpyrifos was classified as an irritant with L/D= 0.14. On the other hand, the HC50 obtained photo hemolysis assays irradiated red blood cells was similar for each organophosphate (Acetate, Chlorpyrifos, Malathion, Methamidophos, Methyl Parathion) indicating no phototoxic action.

CONCLUSION

As a conclusion, it can be said that the parameters of haemolysis and denaturation of proteins are good indicators to classify organophosphorus formulated with surfactants as irritating or phototoxic.

Exposure to the mixture of organophosphorus pesticides is embryotoxic and teratogenic on gestational rats during the sensitive period

Mixture of organophosphorus pesticides (MOPs) has been used worldwide to increase food production. The MOPs are harmful, and the exposure to them is both agricultural and nonagricultural through contaminated food. The neurotoxicity of MOPs has received more consideration recently due to the increased cases of malformed fetuses suspected to be caused by the MOPs exposure during gestation; however, relevant studies in animal model are rare. In this study, we performed a comprehensive analysis and demonstrated potential perinatal embryotoxicity and teratogenicity of MOPs exposure. As results, we found that MOPs decreased in utero fetal growth and alter the ratio of organs to whole body weight of the pregnant rats. MOPs also had been shown to disturb the balance of sex hormones and affect the reproduction of rats. Furthermore, we found various significantly elevated deformities in MOPs exposed embryos, confirming the embryotoxic and teratogenic effects of maternal exposure to MOPs. © 2015 Wiley Periodicals, Inc. Environ Toxicol 32: 139-146, 2017.

Development of an adverse outcome pathway for acetylcholinesterase inhibition leading to acute mortality

Adverse outcome pathways (AOPs) are designed to describe linkages of key events within a biological pathway that result in an adverse outcome associated with chemical perturbation of a well-defined molecular initiating event. Risk assessors have traditionally relied on data from apical endpoints (e.g., mortality, growth, reproduction) to derive benchmark values for use in determining the potential adverse impacts of chemicals. One goal in building reliable and well-characterized AOPs is to identify relevant in vitro assays and/or in vivo biomarkers that could be used in screening the potential hazard of substances, thereby reducing costs and increasing the number of chemicals that can be evaluated in a timely fashion. The purpose of this review article is to build an AOP for substances with a molecular initiating event of acetylcholinesterase inhibition leading to acute mortality following guidance developed by the Organisation for Economic Cooperation and Development. In contrast to most other AOPs developed to date, in which coverage is for a relatively limited taxonomic group or life stage, this AOP is applicable to a wide range of species at multiple life stages. Furthermore, while development of most AOPs has relied on data for a few model chemicals, the AOP described in the present review captures information from a large number of studies with a diversity of organophosphate and carbamate insecticides.