Effect of Sub-Acute Oral Exposure of Bifenthrin on Biochemical Parameters in Crossbred Goats

Dose-Dependent Oxidative Damage in Erythrocytes and Hepatic Tissue of Wistar Rats Concurrently Exposed with Arsenic and Quinalphos: a Subacute Study

Concurrent exposure to a multitude of environmental toxicants pose serious health hazard to humans and animals. The present investigation was conceptualized to determine deleterious effects of concomitant subacute arsenic and quinalphos exposure on antioxidant responses of liver and erythrocytes of Wistar rats. Fifty-four Wistar rats were divided into nine groups with six animals in each. Animals were exposed to either quinalphos (1/100^th and 1/10^th of LD₅₀) through oral gavage daily or arsenic (50 and 100 ppb) in drinking water alone and in combination for 28 days. While treatment with different toxicants alone also significantly reduced hemoglobin concentration, hepatic biomarkers and levels of antioxidant parameters as compared with control values, concomitant exposure significantly (P < 0.05) elevated levels of hepatic transaminases and alkaline phosphatase. Moreover, along with significant depletion in activities of SOD, CAT, TTH, AChE, and enzymes of glutathione complex, a significant enhancement of lipid peroxidation was also recorded in liver and erythrocytes in co-exposed animals in a dose-dependent manner when compared with exposure to individual toxicant. More severe alterations occurred in hepatic histo-architecture of rats receiving combined treatment as compared with those treated with either toxicant. Results indicated that oxidative damage in erythrocytes was more than that of the liver of rats on concomitant exposure of arsenic and quinalphos in a dose-dependent manner. In nutshell, our results revealed that combined treatment of quinalphos with arsenic potentiated toxic effects of either toxicant on antioxidant machinery of liver and erythrocytes and hepatic histomorphology of exposed Wistar rats.

Dietary Exposure to Bifenthrin and Fipronil Impacts Swimming Performance in Juvenile Chinook Salmon (Oncorhynchus tshawytscha)

Two commonly used insecticides, bifenthrin and fipronil, can accumulate in the prey of juvenile Chinook salmon, yet the effects of dietary exposure are not understood. Therefore, to better characterize the effect of a dietary exposure route, juvenile Chinook salmon were fed chironomids dosed with a concentration of 9 or 900 ng/g of bifenthrin, fipronil, or their mixture for 25 days at concentrations previously measured in field-collected samples. Chinook were assessed for maximum swimming performance (U_max) using a short-duration constant acceleration test and biochemical responses related to energetic processes (glucose levels) and liver health (aspartate aminotransferase (AST) activity). Chinook exposed to bifenthrin and bifenthrin and fipronil mixtures had a significantly reduced swimming performance, although not when exposed to fipronil alone. The AST activity was significantly increased in bifenthrin and mixture treatments and glucose levels were increased in Chinook following a mixture treatment, although not when exposed to fipronil alone. These findings suggest that there are different metabolic processes between bifenthrin and fipronil following dietary uptake that may influence toxicity. The significant reductions in swimming performance and increased levels of biochemical processes involved in energetics and fish heath could have implications for foraging activity and predator avoidance in wild fish at sensitive life stages.

Identification of cattle poisoning by Bifenthrin via earwax analysis by HS/GC-MS

The use of pyrethroids has increased over recent years, and corresponds to a higher exposure of animals to pesticide residues in the environment and diet. Here, an outbreak of pyrethroid poisoning in beef cattle was reported occurring in Midwestern Brazil. After veterinary evaluation, it was observed that the bovines presented common pyrethroid intoxication symptoms. Aiming to identify the cattle poising by pyrethroid, earwax samples were collected from two groups: exposed and nonexposed animals from the same farm. Blind earwax analyses of the bovines were carried out using headspace/gas chromatography-mass spectrometry (HS/GC-MS). The HS/GC-MS analysis detected the presence of bifenthrin in the earwax analysis of the exposed animals, confirmed by the comparison of its MS fragments with a bifenthrin standard, and also by its retention time relative to the internal standard. In summary, HS/GC-MS analysis of earwax emerges as a tool that can be used in the detection and monitoring of bifenthrin poisoning in cattle, as a useful veterinary diagnosis that ensures animal health and the safety of their products.

Pyrethroid exposure and neurotoxicity: a mechanistic approach

Pyrethroids are a class of synthetic insecticides that are used widely in and around households to control the pest. Concerns about exposure to this group of pesticides are now mainly related to their neurotoxicity and nigrostriatal dopaminergic neurodegeneration seen in Parkinson’s disease. The main neurotoxic mechanisms include oxidative stress, inflammation, neuronal cell loss, and mitochondrial dysfunction. The main neurodegeneration targets are ion channels. However, other receptors, enzymes, and several signalling pathways can also participate in disorders induced by pyrethroids. The aim of this review is to elucidate the main mechanisms involved in neurotoxicity caused by pyrethroids deltamethrin, permethrin, and cypermethrin. We also review common targets and pathways of Parkinson’s disease therapy, including Nrf2, Nurr1, and PPARγ, and how they are affected by exposure to pyrethroids. We conclude with possibilities to be addressed by future research of novel methods of protection against neurological disorders caused by pesticides that may also find their use in the management/treatment of Parkinson’s disease.

Effect of bifenthrin on oxidative stress parameters in the liver, kidneys, and lungs of rats

Oxidative stress inducing potential of bifenthrin was evaluated in the liver, kidney, and lung of rats following its repeated oral administration for 20 and 30 days. Bifenthrin-treated rats showed a significant lipid peroxidation in all three tissues. By 20th day of treatment, there was a significant decrease in superoxide dismutase activity of the liver, catalase and glutathione peroxidase activity of the liver and lung, and glutathione S-transferase activity of the kidney and lung. By 30th day of exposure, the activities of these enzymes were significantly decreased in all three tissues. The highest oxidative stress, indicated by lipid peroxidation and alteration in antioxidant enzymes, is produced in the liver followed by the kidney and lung. In conclusion, bifenthrin has a potential to induce severe oxidative stress in the liver, kidney, and lung. The extent of oxidative stress is increased with the duration of exposure.

Effect of deltamethrin and fluoride co-exposure on the brain antioxidant status and cholinesterase activity in Wistar rats

The study evaluated the effect of commercial preparation of deltamethrin, Butox^®, and fluoride (F^-) co-exposure on the brain antioxidant status and cholinesterase activity in rats. Group A was untreated. Group B was gavaged Butox^®, providing deltamethrin at the dose rate of 1.28 mg per kg body weight per day. Group C was administered F^-, as NaF, in drinking water providing 20 ppm F^-. Group D received both deltamethrin and F^- at the same dosages as groups B and C, respectively. Although, glutathione S-transferase activity was induced only in Butox^® alone treated group, the activities of superoxide dismutase and catalase were inhibited in all treatment groups when compared to the control group. Elevated lipid peroxidation was observed in the groups exposed to F^-. The activity of erythrocyte acetylcholinesterase (AChE) was inhibited in Butox^® treated groups, whereas brain AChE activity was inhibited in all treatment groups. In conclusion, both deltamethrin (given as Butox^®) and F^- inhibit AChE activity and produce oxidative stress in brain with F^- producing more oxidative damage. However, compared to the individual exposures, the co-exposure of these chemicals does not produce any exacerbated alteration in these biochemical parameters.