Effect of organophosphate pesticide Sumithion (Fenitrothion) on some aspects of carbohydrate metabolism in a freshwater fish, Sarotherodon (Tilapia) mossambicus (Peters)

Ecotoxicological Risk Assessment of Actellic 50 EC Insecticide on Non-Target Organisms in Parallel with the Application of Standardized Tests

This paper contributes to the ecotoxicological risk assessment of the Actellic 50 EC insecticide (with 50% pirimiphos-methyl as the active substance) tested on non-target organisms. The insecticide concentrations tested were the same for all organisms (0.1, 0.01, and 0.001 mg L^-1 of Actellic 50 EC), with an exposure of 3-5-21 days for plants and 4-5-14 days for animals. The non-target organisms tested were both plants (wheat and two ferns) and animals (the Prussian carp and marsh frog tadpoles). The tested insecticide significantly inhibited the growth of roots in wheat, a result that was also confirmed by a microbiotest application (62% root growth inhibition in sorghum and 100% germination inhibition in white mustard and garden cress). In ferns, even for the lowest concentration, the percentage of germinated spores was inhibited by 40% for Asplenium scolopendrium. The recorded toxicological effects of Actellic 50 EC upon the Prussian carp included a decrease in the respiratory rate and oxygen consumption, an increase in the number of erythrocytes and leukocytes, and an increase in blood glucose levels. The highest concentration (0.1 mg L^-1 of Actellic 50 EC) caused a 50% decrease in the survival rate of marsh frog tadpoles after 5 days of exposure, negatively affecting body volume and length. Given the high degree of toxicity of the insecticide Actellic 50 EC, we recommend continuing investigations on non-target species, including both plants and animals, as the sub-chronic effects are quite little known in the scientific literature.

Organophosphate pesticides and new-onset diabetes mellitus: From molecular mechanisms to a possible therapeutic perspective

Organophosphate is a commonly used pesticide in the agricultural sector. The main action of organophosphate focuses on acetylcholinesterase inhibition, and it therefore contributes to acute cholinergic crisis, intermediate syndrome and delayed neurotoxicity. From sporadic case series to epidemiologic studies, organophosphate has been linked to hyperglycemia and the occurrence of new-onset diabetes mellitus. Organophosphate-mediated direct damage to pancreatic beta cells, insulin resistance related to systemic inflammation and excessive hepatic gluconeogenesis and polymorphisms of the enzyme governing organophosphate elimination are all possible contributors to the development of new-onset diabetes mellitus. To date, a preventive strategy for organophosphate-mediated new-onset diabetes mellitus is still lacking. However, lowering reactive oxygen species levels may be a practical method to reduce the risk of developing hyperglycemia.

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.

(1)H NMR based metabolomics approach to study the toxic effects of dichlorvos on goldfish (Carassius auratus)

Dichlorvos (DDVP), one of the most widely used organophosphorus pesticides (OPs), has caused serious pollution in environment. In this study, (1)H nuclear magnetic resonance (NMR) based metabolomics approach combined with histopathological and immunohistochemical examination, and biochemical assays were used to investigate toxicities of DDVP on goldfish (Carassius auratus). After 10 days' exposure of DDVP at three dosages of 5.18, 2.59 and 1.73 mg/L, goldfish tissues (gill, brain, liver and kidney) and serum were collected. Histopathology revealed severe impairment of gills, livers and kidneys, and immunohistochemistry disclosed glial fibrillary acidic protein (GFAP) positive reactive astrocytes in brains. Orthogonal signal correction-partial least squares-discriminant analysis (OSC-PLS-DA) of NMR profiles disclosed that DDVP influenced many metabolites (glutamate, aspartate, acetylcholine, 4-aminobutyrate, glutathione, AMP and lactate in brain; glutathione, glucose, histamine in liver; BCAAs, AMP, aspartate, glutamate, riboflavin in kidney) dose-dependently, involved with imbalance of neurotransmitters, oxidative stress, and disorders of energy and amino acid metabolism. Several self-protection mechanisms concerning glutamate degradation and glutathione (GSH) redox system were found in DDVP intoxicated goldfish.

Differential expression profile of membrane proteins in Aplysia pleural–pedal ganglia under the stress of methyl parathion

This study was aimed to analyze the alteration of membrane protein profiles in Aplysia juliana Quoy & Gaimard (A. juliana) pleural–pedal ganglia under MP exposure. Both the results of GC–MS analysis and the activity assay of acetylcholinesterase (AChE), superoxide dismutase (SOD), catalase (CAT) reveal that MP toxicological effects on Aplysia left and right pleural–pedal ganglia are different under 7 and 14 days of exposure. Therefore, Aplysia were subjected for exposure at two concentrations (1 and 2 mg/l) of MP for 7 and 14 days for membrane proteomic study. As a result, 19 and 14 protein spots were differentially expressed in A. juliana left pleural–pedal ganglia under 7 and 14 days treatment, and 20 and 14 protein spots found with differential expressions in their right ganglia under the same treatment, respectively. Several proteins with expression variations were detected from both the left and right pleural–pedal ganglia; however, most proteins have distinctive expressions, indicating different mechanisms might be involved in initiating MP toxicology in left and right ganglia. Among the total differential protein spots obtained, 29 proteins were classed as membrane proteins. These proteins are mainly involved in the metabolism process, cell redox homeostasis, signal transduction, immunology, intracellular transport and catalysis, indicating MP toxicity in mollusks seems to be complex and diverse. Some differentially expressed proteins were further confirmed by Western blotting and quantitative real-time PCR. These results might provide renovated insights to reveal the mechanism of MP-induced neurotoxicity, and the novel candidate biomarkers might have potential application for environmental evaluation of MP pollution level.

Pesticides and human diabetes: a link worth exploring?

It is no exaggeration to claim that the 'diabetes epidemic' has become a 'runaway train' causing huge health and economic consequences, especially in the developing nations. Traditionally, the risk factors for diabetes have largely focused on genetics and lifestyle. Great emphasis is placed on lifestyle measures and finding novel pharmacological treatment options to combat diabetes, but there is increasing evidence linking environmental pollutants, especially pesticides, to the development of insulin resistance and Type 2 diabetes. Pesticide use has increased dramatically worldwide and the effects of pesticides on glucose metabolism are too significant for a possible diabetogenic link to be dismissed. The aim of this review article was to assess the links between pesticides and human diabetes with the goal of stimulating further research in this area.

Alterations of protein profile in zebrafish liver cells exposed to methyl parathion: a membrane proteomics approach

Methyl parathion (MP) is an extensively used organophosphorus pesticide, which has been associated with a wide spectrum of toxic effects on environmental organisms. The aim of this study is to investigate the alterations of membrane protein profiles in zebrafish liver (ZFL) cell line exposed to MP for 24 h using proteomic approaches. Two-dimensional gel electrophoresis revealed a total of 13 protein spots, whose expression levels were significantly altered by MP. These differential proteins were subjected to matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry analysis, and nine proteins were identified to be membrane proteins, among which seven were up-regulated, while two were down-regulated. In addition, the mRNA levels corresponding to these differential membrane proteins were further analyzed by quantitative real-time PCR. And the differential expression of arginase-2 was specially validated via Western blotting. Regarding the physiological functions, these proteins are involved in molecular chaperon, cytoskeleton system, cell metabolism, signal transduction, transport and hormone receptor respectively, suggesting the complexity of MP-mediated toxicity to ZFL cell. These data could provide useful insights for better understanding the hepatotoxic mechanisms of MP and develop novel protein biomarkers for effectively monitoring MP contamination level in aquatic environment.

Toxic influence of organophosphate, carbamate, and organochlorine pesticides on cellular metabolism of lipids, proteins, and carbohydrates: a systematic review

Pesticides, including organophosphate (OP), organochlorine (OC), and carbamate (CB) compounds, are widely used in agricultural and indoor purposes. OP and CB act as acetyl cholinesterase (AChE) inhibitors that affect lots of organs such as peripheral and central nervous systems, muscles, liver, pancreas, and brain, whereas OC are neurotoxic involved in alteration of ion channels. There are several reports about metabolic disorders, hyperglycemia, and also oxidative stress in acute and chronic exposures to pesticides that are linked with diabetes and other metabolic disorders. In this respect, there are several in vitro and in vivo but few clinical studies about mechanism underlying these effects. Bibliographic databases were searched for the years 1963-2010 and resulted in 1652 articles. After elimination of duplicates or irrelevant papers, 204 papers were included and reviewed. Results indicated that OP and CB impair the enzymatic pathways involved in metabolism of carbohydrates, fats and protein within cytoplasm, mitochondria, and proxisomes. It is believed that OP and CB show this effect through inhibition of AChE or affecting target organs directly. OC mostly affect lipid metabolism in the adipose tissues and change glucose pathway in other cells. As a shared mechanism, all OP, CB and OC induce cellular oxidative stress via affecting mitochondrial function and therefore disrupt neuronal and hormonal status of the body. Establishing proper epidemiological studies to explore exact relationships between exposure levels to these pesticides and rate of resulted metabolic disorders in human will be helpful.

The toxicity of four native Indian plants: effect on AChE and acid/alkaline phosphatase level in fish Channa marulius

The latex of four plants viz. Euphorbia royleana, Jatropha gossypifolia (Euphorbiaceae), Nerium indicum and Thevetia peruviana (Apocynaceae) caused significant reduction in acid/alkaline phosphatase activity and anti-acetylcholinesterase activity in nervous tissue of freshwater air breathing fish Channa marulius. The reduction in the activity of both phosphatases and AChE were time as well as dose dependent.

Comparative toxicity and biochemical responses of certain pesticides to the mature earthworm Aporrectodea caliginosa under laboratory conditions

This study was conducted to investigate the toxicity of aldicarb, cypermethrin, profenofos, chlorfluazuron, atrazine, and metalaxyl toward mature Aporrectodea caliginosa earthworms. The effects of the LC(25) values of these pesticides on the growth rate in relation to glucose, soluble protein, and activities of glutamic-oxaloacetic transaminase (GOT), glutamic-pyruvic transaminase (GPT), acid phosphatase (AcP), and alkaline phosphatase (AIP) were also studied. The results showed that aldicarb was the most toxic of the tested pesticides, followed in order by cypermethrin, profenofos, chlorfluazuron, atrazine, and metalaxyl. A reduction in growth rate was observed in all pesticide-treated worms, which was accompanied by a decrease in soluble protein and an increase in transaminases and phosphatases. Relationships between growth rate, protein content, transaminases, and phosphatases provided strong evidence for the involvement of pesticidal contamination in the biochemical changes in earthworms, which can be used as a bioindicator of soil contamination by pesticides.

Toxicity of cypermethrin in Labeo rohita fingerlings: biochemical, enzymatic and haematological consequences

The effect of exposure to sub-lethal concentrations of cypermethrin, a synthetic pyrethroid pesticide, on biochemical parameters of muscle, blood and enzyme activities in brain, liver and kidney of the Indian major carp, Labeo rohita was studied. The sub-lethal exposure studies were done for up to 45 days at 1/10 and 1/50 of 96 h LC(50) of cypermethrin. The 96 h LC(50) was found to be 0.139 ppm. RNA levels decreased while DNA levels were elevated. Acid phosphatase was unchanged while alkaline phosphatase was depleted. Brain acetylcholinesterase activity was decreased significantly (P<0.05) over a period of 45 days at both cypermethrin concentrations. Lactate dehydrogenase activity in brain and liver was elevated, but inhibited in kidney. Succinate dehydrogenase and ATPase activities were depleted in brain, kidney and liver. There was a decrease in serum protein level over control at both concentrations of the pyrethroid. Blood glucose level and total leucocytes were elevated compared with controls at either concentration from day 15 to day 45. Haemoglobin percentage and total erythrocytes decreased in both sub-lethal concentrations. Extracts of the herb Datura stramonium were effective in countering the toxicity of this pesticide. Our data suggest that sub-lethal exposure of cypermethrin alters the biochemical, haematological parameters and enzymes of organs tissue and exert stress on the fish. Plant extracts may be useful in counteracting some of these effects.

Chronic toxic effects of quinalphos on some biochemical parameters in Labeo rohita (Ham.)

The effect of exposure to sublethal concentrations of the organophosphate pesticide, quinalphos (1.12, 0.22 mg/l) on biochemical parameters of muscle and enzyme activities in brain, liver and kidney of the Indian major carp, Labeo rohita was studied after 15, 30 and 45 days. The muscle protein and RNA levels decreased whereas DNA levels and acid phosphatase were elevated. Similarly, alkaline phosphatase was depleted. The brain acetyl cholinesterase activity was decreased most (-75.43%) in 1.12 mg/l concentration over a period of 45 days. Lactic dehydrogenase levels in brain and liver were elevated whereas in the kidney they were inhibited. Succinic dehydrogenase and adenosine triphosphatase activities were depleted in brain, liver and kidney. The effects have been discussed for different organ tissues in relation to the pesticide.

Effect of acute exposure of the organophosphate insecticide Rogor on some biochemical aspects of Clarias batrachus (Linnaeus)

Indian catfish (Clarias batrachus), a common fish of commercial importance, was exposed to a sublethal concentration (1/3 of 96 h LC50 value) of Rogor for periods ranging from 24 to 192 h. The changes in glycogen, lactate, lactate dehydrogenase, and glycogen phosphorylase (a, ab) contents of muscle tissue were studied. A gradual decrease in muscle glycogen and an increase in lactate contents were observed. The activity level of lactate dehydrogenase showed a sharp rise initially for 48 h followed by a decline after 96 and 192 h. The glycogen phosphorylase a and ab in muscle tissue enhanced in response to Rogor exposure.

Carbohydrate metabolism in hepatic tissue of freshwater catfish Clarias batrachus L. during dimethoate exposure

Clarias batrachus L., a freshwater catfish of commercial importance, was exposed to a sublethal concentration of dimethoate (Rogor). The acute effect of dimethoate on some aspects of carbohydrate metabolism of hepatic tissue was studied after 1, 2, 4 and 8 days. The glycogen content was depleted, whereas the lactate level was elevated throughout the experimental period and an increase in lactate dehydrogenase was observed. The activity levels of glycogen phosphorylase a and ab in the hepatic tissue were increased during dimethoate stress. The results suggest that carbohydrate metabolism was adversely affected in the hepatic tissue by the organophosphate insecticide dimethoate.

The possible role of glucose-6-phosphate dehydrogenase in the detoxification of methyl parathion

The levels of proteins, glucose and glucose-6-phosphate dehydrogenase activity were studied in muscle, gill and liver tissues of the fish Tilapia mossambica under sublethal methyl parathion toxicity. Tissue glucose levels decreased with increased soluble protein content and the activity levels of glucose-6-phosphate dehydrogenase were elevated considerably. These results are discussed in relation to the involvement of glucose-6-phosphate dehydrogenase in both synthetic and detoxification processes as an adaptive response against methyl parathion toxicity.