Growth, tolerance, and enzyme activities of Trichoderma strains in culture media added with a pyrethroids-based insecticide

The application of pyrethroids and carbamates represents an environmental risk and may exert adverse effects on beneficial microorganisms such as Trichoderma, which contribute to the biocontrol of several fungal phytopathogens. This research evaluated the tolerance of several strains of Trichoderma to a selected culture medium contaminated with a commercial insecticide (H24®) composed of pyrethroids, permethrin and prallethrin, and carbamate propoxur, and determined the influence of this insecticide on the release of enzymes such as chitinases, peroxidases, and endoglucanases by a consortium of selected Trichoderma strains grown in liquid culture medium. Four out of 10 Trichoderma strains showed tolerance to 200ppm (∼48.3% of growth) of the commercial insecticide after 96h of exposure to a contaminated solid medium. After eight days of growth in liquid culture, the insecticide enhanced extracellular protein content and peroxidase activities in the Trichoderma consortium but decreased both chitinase and glucanase activities. These fungal responses should be considered when implementing strategies that combine alternative pesticides and fungal biocontrollers for managing fungal phytopathogens.

Efficacy of topical administration of prallethrin-permethrin-piperonyl butoxide (Bronco® Equine Fly Spray) for the treatment and control of flies and other nuisance insects of horses

Numerous biting and nuisance insects are a noted cause of discomfort and stress to horses. Pyrethrins and pyrethroids have been used for many years in numerous formulations for the control of insect pests in animals, humans and environment. There are, however, few studies reporting their field efficacy in horses. The aim of the present study was to evaluate the repellent activity of a spray formulation based on prallethrin and permethrin synergized with piperonyl butoxide (BRONCO® Equine Fly Spray, Farnam Companies, Inc., USA) against annoying and harmful insects for horses in field conditions. Nine horses of mixed breed were divided into 2 groups (treatment and control). Pre-treatment insect counts were compared to daily counts for 4 days post-treatment (pt). One minute after the administration of the product (day 0), all the horses were negative for the presence of insects. All counts up to the 6-h pt check remained negative for Hippobosca equina, tabanid flies and Simulium spp., showing 100% efficacy. This remained above 90% throughout the study. For the H. equina, the repellent efficacy remained > 99.7% for all 4 days pt, for tabanid flies > 93.3% and for Simulium spp. > 97.4%. The efficacy against Musca spp. decreased from 82.2% at day 0 to 62.2% at day 3. Treatment was well-tolerated. In conclusion, despite the low number of tested horses, Bronco® has demonstrated high insecticide and repellent efficacy and a good persistence, maintained for up to 4 days post-treatment, against the most common species of insects harmful for horses.

Household based-pyrethroids on adult zebrafish (Danio rerio) exert behavioral and cholinergic changes in different brain regions

Pyrethroid-based insecticides are largely used for mosquito control. These compounds have household and agricultural applications with different formulations. Two important compounds used as household insecticides are prallethrin and transfluthrin, both from the pyrethroid chemical group. With the mode of action centered on sodium channels, pyrethroids keep the ionic sodium channels open for a long time causing the death of the insect by nervous hyperexcitability. Given the increased use of household insecticides by humans and the incidence of disease outbreaks with unknown etiology such as autism spectrum disease, schizophrenia, and Parkinson's disease we investigate some physiological inputs of these compounds on zebrafish. In this study, we evaluated the social interaction, shoaling formation, and anxiety-like behavior of zebrafish exposed chronically to transfluthrin- and prallthrin-based insecticides (T-BI and P-BI). In addition, we quantified the activity of the enzyme acetylcholinesterase (AChE) in different brain regions. We observed that both compounds caused anxiolytic behavior and reduced shoaling formation and social interaction. Their behavioral biomarkers indicated a harmful ecological effect on the specie as well as a possible impact of these compounds on autism spectrum disorder (ASD) and schizophrenia (SZP). In addition, the AChE activity would change its activity in different brain regions modulating the anxiety-like behavior and social behavior in zebrafish. We conclude that P-BI and T-BI make us alert about the relationship of these compounds with nervous diseases related to cholinergic signaling.

Phenotypic profile of Aedes albopictus (Skuse) exposed to pyrethroid-based mat vaporizers and underlying detoxification mechanisms: A statewide report in Selangor, Malaysia

This study examines the biological efficacy of four mosquito mat vaporizers each containing different active ingredients: prallethrin with PBO, dimefluthrin, prallethrin, and d-allethrin. The glass chamber assay was used to evaluate their efficacy on Aedes albopictus (Skuse) (Diptera: Culicidae) from nine districts in Selangor, Malaysia. Aedes albopictus exhibited different knockdown rates, with 50% knockdown times, KT₅₀, varying from 1.19 to 2.00 min, 1.22 to 2.20 min, 1.39 to 5.85 min, and 1.39 to 1.92 min for prallethrin with PBO, dimefluthrin, prallethrin and d-allethrin, respectively. In general, all populations of Ae. albopictus were completely knocked down after exposure to all active ingredients except Hulu Selangor population, which showed 96.00% knockdown against d-allethrin. On the contrary, mortality rates were observed from 84.00-100.00%, 84.00-100.00%, 90.67-100.00% and 90.67-100.00% in populations tested with prallethrin with PBO, dimefluthrin, prallethrin and d-allethrin, respectively. Moreover, significant correlations between mortality rates of prallethrin with PBO vs dimefluthrin (r = 0.836, P = 0.003), prallethrin with PBO vs prallethrin (r = 0.760, P = 0.011), and prallethrin vs d-allethrin (r = 0.694, P = 0.026) were also observed, suggesting cross-resistance among pyrethroids. d-allethrin was found to be high in insecticidal activity, followed by prallethrin, prallethrin with PBO, and dimefluthrin. In consistent with mortality due to insecticide exposure, elevated levels of enzyme activities were also demonstrated in Sabak Bernam, Hulu Selangor, Gombak, Petaling, Hulu Langat and Klang populations.

Induced alteration of rat erythrocyte membrane with effect of pyrethroid based compounds

The effects of tetramethrin and prallethrin exposure on plasma total proteins, free amino acids, albumins, urea, urea nitrogen, uric acid, creatinine were tested. Serum SGOT, SGPT and lipid profile, antioxidants super oxide dismutase (SOD), catalase, GSH, G-Px, phospholipids, cholesterol, C/P ratio in membranes of erythrocyte and membrane fluidity were analyzed. The reason of the study were analyzed to examine the possessions of mosquito repellent pyrethroid (MRP) based compounds tetramethrin and prallethrin exposure on plasma profile, antioxidant status of erythrocyte membrane, membrane fluidity in male Wistar rats. We tested chronically for three months exposure every day (continuously for 8-10 h per day by inhalation) of tetramethrin and prallethrin markedly available (MRP) repellents treated on male Wistar rats. Our results confirmed that tetrarmethrin and prallethrin treatment effect of plasma profile alterations, and lipid homeostasis mechanism in Red Blood cells (RBCs). Tetramethrin and prallethrin treatment significantly increased in erythrocyte membrane phospholipids and decreased levels of cholesterol with no change of protein content, increased C/P ration levels. Inhalation of tetramethrin and prallethrin stimulate plasma biophysical and biochemical modify SGOT, SGPT, erythrocyte membrane cholesterol and phospholipid levels, individual phospholipids and membrane fluidity of exposure rats compared to controls.

The effects of particulate matters inhalation exposures of prallethrin and d-phenothrin mixture in mice (Mus musculus) against exhaled carbon dioxide concentration

Particulate matter (PM) inhalation exposure affects exhaled CO₂ concentration. Such exhaled CO₂ refers to ventilation and perfusion of the cardiorespiratory system, the analysis of which is painless, non-invasive and simple to perform. This study examined the effect of prallethrin and d-phenothrin inhalation exposure on exhaled CO₂ in mice using a simple method. Prallethrin and d-phenothrin were administered in male mice (Mus musculus) in a series of repeated inhalation exposures of lower and higher doses for 60 days. The lower dose was a mixture of 0.000141 mg/L prallethrin and 0.104 mg/L d-phenothrin, while the higher dose was a mixture of 0.00141 mg/L prallethrin and 1.04 mg/L d-phenothrin. The lower dose was based on a NOAEL value of prallethrin and d-phenothrin of 28 days exposure, while the higher one was ten times of the lower dose concentration. CO₂ concentration was measured by means of the passage through NaOH 0.1 N, titrated by HCl 0.1 N. PMs were generated by the process of producing bubbles, inserted into the chamber containing mice. Mice were divided into four groups, namely: negative control (NC), positive control (PC), and lower- and higher-dose treatment groups, with three replicates for each group. Statistical difference analyses were observed in body weight and exhaled CO₂ concentration between negative control and treatment groups, nevertheless, they did not differ significantly between the control and the treatment (lower and higher dose) groups. This study suggests that exhaled CO₂ and body weight are not specific biomarkers to observe PMs inhalation exposure with respect to prallethrin and d-phenothrin mixtures.

Oxidative damage and nephrotoxicity induced by prallethrin in rat and the protective effect of Origanum majorana essential oil

OBJECTIVE

To investigate the effects of prallethrin on renal dysfunction biomarkers, antioxidant enzyme activities and lipid peroxidation (LPO) in rats and the protective effect of Origanum majorana essential oil.

METHODS

Rats were divided into four groups of seven rats in each group: (I) received only olive oil, (II) treated with 64.0 mg/kg body weight prallethrin (1/10 LD50) in olive oil via oral route daily for 28 d, (III) treated with 64.0 mg/kg body weight prallethrin (1/10 LD50) and essential oil (160 μL/kg body weight) in olive oil and (IV) received essential oil (160 μL/kg body weight) in olive oil via oral route twice daily for 28 d.

RESULTS

Prallethrin caused significant increase in LPO and decrease in superoxide dismutase, glutathione peroxidase and glutathione reduced. Consistent histological changes were found in the kidney of prallethrin treatment. Co-administration of essential oil attenuated the prallethrin induced renal toxicity and oxidative stress by decreasing LPO in kidney, creatinine, urea and uric acid levels in serum. In addition, superoxide dismutase, glutathione peroxidase activity and glutathione reduced level were increased in kidney in prallethrin-essential oil groups.

CONCLUSIONS

We can conclude that prallethrin induced oxidative damage and renal toxicity in male rat. The administration of essential oil provided significant protection against prallethrin-induced oxidative stress, biochemical changes and histopathological damage.

Prallethrin poisoning: A diagnostic dilemma

Pyrethroid insecticides are very widely used in agriculture and household due to their high effectiveness and low toxicity in humans. Despite their extensive worldwide use, there are a few reports of human pyrethroid poisoning. The poisoning has a varied presentation and its symptoms overlap with those of other compounds, which can lead to misdiagnosis. We present a case of poisoning with prallethrin, a pyrethroid compound, commonly available as All-Out.