Evaluation of the toxic effects of cypermethrin inhalation on the frog heart

Investigation of the role of KATP channels in the cytotoxic effect of cypermethrin on rat-derived aortic smooth muscle cells

We investigate role of ATP sensitive potassium (KATP) channel in cytotoxic effect of cypermethrin on rat aortic smooth muscle cells. Cytotoxicity analysis was performed at 0, 0.1, 0.5, 10, 50, and 100 µM concentrations of cypermethrin and the cell index (CI) was calculated. KATP currents were recorded using patch clamp technique for 50 and 100 µM concentrations and channel conductivity was determined by obtaining current-voltage characteristics. No cytotoxic effect was observed in the first 72 hours. At the 96th hour, only at 100 µM concentration, the CI value decreased significantly compared to control group and at 120 and 144th hours, it was observed that the CI value decreased significantly at all concentrations. Currents and conductivities were significantly decreased at 50 and 100 µM concentrations. Results gave clues that cypermethrin causes a cytotoxic effect on vascular smooth muscles and that KATP channels may have a role in the emergence of this effect.

Cardiotoxicity of some pesticides and their amelioration

Pesticides are used to control pests that harm plants, animals, and humans. Their application results in the contamination of the food and water systems. Pesticides may cause harm to the human body via occupational exposure or the ingestion of contaminated food and water. Once a pesticide enters the human body, it may create health consequences such as cardiotoxicity. There is not enough information about pesticides that cause cardiotoxicity in the literature. Currently, there are few reports that summarized the cardiotoxicity due to some pesticide groups. This necessitates reviewing the current literature regarding pesticides and cardiotoxicity and to summarize them in a concrete review. The objectives of this review article were to summarize the advances in research related to pesticides and cardiotoxicity, to classify pesticides into certain groups according to cardiotoxicity, to discuss the possible mechanisms of cardiotoxicity, and to present the agents that ameliorate cardiotoxicity. Approximately 60 pesticides were involved in cardiotoxicity: 30, 13, and 17 were insecticides, herbicides, and fungicides, respectively. The interesting outcome of this study is that 30 and 13 pesticides from toxicity classes II and III, respectively, are involved in cardiotoxicity. The use of standard antidotes for pesticide poisoning shows health consequences among users. Alternative safe medical management is the use of cardiotoxicity-ameliorating agents. This review identifies 24 ameliorating agents that were successfully used to manage 60 cases. The most effective agents were vitamin C, curcumin, vitamin E, quercetin, selenium, chrysin, and garlic extract. Vitamin C showed ameliorating effects in a wide range of toxicities. The exposure mode to pesticide residues, where 1, 2, 3, and 4 are aerial exposure to pesticide drift, home and/or office exposure, exposure due to drinking contaminated water, and consumption of contaminated food, respectively. General cardiotoxicity is represented by 5, whereas 6, 7, 8 and 9 are electrocardiogram (ECG) of hypotension due to exposure to OP residues, ECG of myocardial infraction due to exposure to OPs, ECG of hypertension due to exposure to OC and/or PY, and normal ECG respectively.

Inhalation of publicly available indoor insecticide spray caused myocardial infarction type II: a case report

We report on a 70‐year‐old woman who tried to eliminate ants from her kitchen by applying a publicly available insecticide spray. Immediately afterwards, she felt dyspnoea, superseded by heavy chest pain. High‐sensitivity troponin concentration increased from 33 to 149 ng/L (cut‐off 50 ng/L). Significant coronary stenosis was excluded by coronary angiography, and the myocardial damage was classified as myocardial infarction type II. After exclusion of other potential mechanisms, we consider a cardiotoxic effect of the insecticide mixture of cypermethrin, tetramethrin, and piperonyl butoxide possible. We conclude that consumer information has to be improved. This concerns sustainable control measures adapted to the target insect species (in this case, the black garden ant Lasius niger), and differentiation between authorized and non‐authorized but notified products. The instructions for use should give clear information on vulnerable groups and recommend personal protective equipment. Physicians and authorities should be alert to cardiac side‐effects of insecticides.

Bisoprolol and linagliptin ameliorated electrical and mechanical isometric myocardial contractions in doxorubicin-induced cardiomyopathy in rats

BACKGROUND

Doxorubicin is an anthracycline chemotherapeutic agent that causes cardiomyopathy as a side effect. Here, we aimed to investigate the effects of linagliptin and bisoprolol on the management of doxorubicin-induced cardiomyopathy in rats.

METHODS

Wistar rats were divided into six groups (n = 8). Group I received saline for 4 weeks; group II received 1 mg/kg bisoprolol for 8 weeks; group III received 3 mg/kg linagliptin for 8 weeks; group IV received 1.25 mg/kg doxorubicin for 4 weeks for the induction of cardiomyopathy; group V received 1.25 mg/kg doxorubicin for 4 weeks plus 1 mg/kg bisoprolol for 8 weeks; and group VI received 1.25 mg/kg doxorubicin for 4 weeks plus 3 mg/kg linagliptin for 8 weeks. Electrocardiography and isometric mechanography were conducted to measure ventricular contractile responses. Myocardial tissue and serum samples were analyzed for oxidative and cardiotoxic markers by ELISA.

RESULTS

Electrocardiography revealed that QRS, QT and Tp intervals were longer in group IV than group I. Doxorubicin caused a significant decrease in ventricular contraction, which was significantly prevented by bisoprolol. Doxorubicin resulted in myocardial fiber disorganization and disruption, but bisoprolol or linagliptin improved this myocardial damage. Glutathione peroxidase was significantly decreased in groups IV and V. Bisoprolol or linagliptin treatment attenuated the significant doxorubicin-mediated increase in malondialdehyde. Doxorubicin and linagliptin provided significant elevations in CK-MB activity and troponin-I levels.

CONCLUSIONS

Doxorubicin resulted in pronounced oxidative stress. The beneficial effects of bisoprolol and linagliptin on myocardial functional, histopathological and biochemical changes could be related to the attenuation of oxidative load.

Distribution, Metabolism and Toxic Effects of Beta-Cypermethrin in Lizards (Eremias argus) Following Oral Administration

Beta-cypermethrin (BCYP), a synthetic pyrethriod (PYR) pesticide which is a mixture of the alpha- and theta- cypermethrin, have been reported various toxicological profiles to non-target organisms. But little is known about assimilation, accumulation and toxic effects of BCYP in reptiles. The present study firstly elucidated absorption, tissue distribution, excretion of BCYP in Eremias argus . Treated group were administered orally with BCYP 20mg/kg body weight (bw) dissolved in corn oil. Neurotoxicity was observed at 24h after gavage, and the poisoning symptom ameliorated at 72h. The changes of BCYP concentration depended on degradation time and tissues. Lizards had a strong capacity to eliminate BCYP with different tissue distribution. The tissues concentration of BCYP from high to low were intestine, stomach, heart, kidney, blood, lung, liver and brain. Bimodal phenomena were observed in lung, liver and kidney. These results may be due to the activities of enzymes, circadian rhythm, and enterohepatic circulation in lizards. Based on the results of organ coefficient and histopathology analysis in liver, the liver was confirmed as the main target organ.

Impact of an environmental relevant concentration of 17α-ethinylestradiol on the cardiac function of bullfrog tadpoles

This study evaluated if a concentration of 17α-ethinylestradiol (EE2 - 10 ng L(-1) for 96 h) normally found in Brazilian surface waters exerts any impact on cardiac function of bullfrog tadpoles (25 Gosner stage), Lithobates catesbeianus. During exposure, the animals' activity level (AL -% of active individuals) was monitored twice a day. Then, the in loco heart rate (f(H) - bpm) was determined, as well as the relative ventricular mass (RVM - % of body mass). Afterwards, cardiac ventricles were mounted for isometric force recordings (CS - mN mm(-2)), and determination of the cardiac pumping capacity (CPC - mN mm(-2) min(-1)). EE2 did not affect tadpoles' AL, although it resulted in a tachycardia in animals exposed to EE2 (f(H) = 66 bpm) when compared to controls (f(H) = 52 bpm), suggesting that EE2 acts directly on the cardiac muscle of tadpoles, rather than being a result of an increased cardiac demand due to a higher activity level (i.e., avoidance response). Additionally, EE2 exerted a positive inotropic response, which resulted in a higher CPC, which occurred independently of an increase in the number of myofibrils of EE2-exposed animals, since RVM remained similar between experimental groups. Thus, the increase on cardiac demand induced by the exposure to EE2 elevates considerably the animal energy expenditure, diverting a large amount of energy that tadpoles could use for their growth and development. These alterations can make amphibians more susceptible to predators and reduce the likelihood to reach reproductive stage.

Effects of the organophosphorus pesticide Folisuper 600 (methyl parathion) on the heart function of bullfrog tadpoles, Lithobates catesbeianus (Shaw, 1802)

Abstract The aim of this work was to evaluate whether the heart function of bullfrog tadpoles (25 Gosner stage) is affected by their acute exposure (48 h) to a sub-lethal concentration (10 µg.L–1) of the active principle of the organophosphorus pesticide Folisuper 600R (methyl parathion - MP). Our results demonstrated that MP causes not only a reduction in tadpoles’ cardiac ventricular mass, resulting in a marked reduction in their cardiac twitch force, but also impairs their swimming performance, irrespective of increasing their heart rate. Together, these findings indicate that low and realistic concentration of MP have a negative impact on tadpoles’ performance, jeopardizing their survival.

Negative impact of a cadmium concentration considered environmentally safe in Brazil on the cardiac performance of bullfrog tadpoles

A drastic amphibian decline has been observed worldwide, which can be attributed (among other factors) to exposure to pollutants. Considering that cadmium corresponds to the most rapidly increasing trace metal in the environment, the aim of this work was to evaluate whether the exposure (2 and 16 days) of bullfrog tadpoles to this trace metal, at the concentration currently considered environmentally safe (at 1ppb) in class 1 and 2 waters by the Brazilian Environmental Council, can affect the cardiac performance of these animals. The acute exposure (2 days) of tadpoles to cadmium resulted in a marked bradycardic response, which was correlated with an incomplete cardiac relaxation, without any compensation by improved cardiac twitch force (Fc) or contraction velocity (TPT), nor even by cardiac hypertrophy. Indeed, after 16 days of exposure, the cardiac function of tadpoles became even more depressed due to a marked decrease in Fc, a prolongation of TPT, and also incomplete relaxation (i.e. increases in the ventricle resting tension), without changes in ventricle relative mass. Altogether, the cardiodepressive effects of cadmium (especially after more prolonged exposure periods) impose negative alterations on a tadpole׳s development and also impede adequate homeostatic adjustments to respond appropriately to the exposure to cadmium with increase in energetic demand to counteract the deleterious effects of the xenobiotic. These disturbances can impair tadpoles׳ growth, development and reproduction. It is a fact that allows us to strongly suggest that cadmium concentrations, which are currently considered environmentally safe in Brazil, should be revised.