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Field studies on the "Development and evaluation of different management schedules against fruit borer, Helicoverpa armigera infesting tomato crop" were carried at farmer's field, village Surajgarh, Jhajjar, Haryana. The observations on infestation of fruit borer in tomato fruits at the time of each picking, %reduction of the fruit borer infestation, total marketable yield in different schedules over control and benefit cost ratio were calculated. The maximum larval reduction over control was observed in S6 i.e. spray of fenvalerate 20 EC @ 188 ml/ha (79.91%) followed by spray of nimbecidine 300 ppm @ 2.5 l/ha (79.04). On number basis, highest fruit damage reduction over control was observed in S6 (50.23%) followed by S5 (43.83%) and lowest (21.72%) in S4 i.e. African yellow marigold + yellow sticky trap + Trichogramma chilonis Ishi @ 50000 parasitised eggs/ha (2 releases at 4 days interval). On weight basis, %fruit damage reduction over control was maximum in S6 (57.47%) followed by S5 (53.10%) and minimum in S4 (25.06%). The highest benefit cost ratio (22.81) was recorded in S6 due to lowest cost of plant protection (Rs.3628.34/ha) and highest increased yield over control (72 q/ha). Although schedule S4 was next to S6 in term of total cost of plant protection but showed lowest benefit cost ratio (3.46) due to minimum increased yield over control (20 q/ha) among all the management schedules. Benefit cost ratio in remaining schedules were 8.97, 5.40, 3.71 and 3.58 in S5, S1, S2 and S3, respectively. [ABSTRACT FROM AUTHOR]

The diamondback moth, Plutella xylostella (Linnaeus) (Lepidoptera: Plutellidae), is one of the most important pests of cruciferous crops in Iran and is controlled mostly by fenvalerate. The susceptibility to fenvalerate was investigated for four populations of P. xylostella. Bioassay results indicated significant differences among the populations tested. The highest level of resistance to fenvalerate was obtained for the Khuzestan (Khz) population (resistance ratio = 9.5). Survival was suppressed by diethyl maleate, piperonylbutoxide, and triphenyl phosphate, which confirmed that resistance to fenvalerate is caused by glutathione S-transferases (GSTs), mixed function oxidases, and esterases, respectively. Up to 8.6-, 2-, 2.7-, and 1.75-fold increases in GSTs, esterase (α-naphthylacerate and β-naphthyl acetate as substrate), and cytochrome P450 monooxygenases activities in resistant strains when compared with the susceptible one, were observed, respectively. The expression of six GST genes of P. xylostella including GSTs1, GSTe2, GSTe4, GSTo4, GSTd4, and GSTd5 were analyzed. The quantitative PCR analysis showed that three of the PxGSTs had the highest expression levels in the Khz population. Two of the GSTs (GSTd4 and PxGSTe2) exhibited highest expression level in both Khz and Alborz (Alb) populations. Therefore, PxGST genes were involved in fenvalerate resistance in P. xylostella. Overall, the mechanisms of insecticide resistance in diamondback moth populations in four regions of Iran were related to GST, esterase, and cytochrome P450 monooxygenase activities. [ABSTRACT FROM AUTHOR]

Abstract Fenvalerate (FEN), a representative type II pyrethroid, is a widely used pyrethroid insecticide and a potential environmental contaminant. Several studies demonstrated that gestational FEN exposure induced intrauterine growth restriction (IUGR). However, the critical time window of FEN-induced fetal IUGR remains obscure. The present study aimed to identify the critical window of FEN-induced fetal IUGR. Pregnant mice were administered corn oil or FEN (20 mg/kg) by gavage daily at the early gestational stage (GD0-GD6), middle gestational stage (GD7-GD12) or late gestational stage (GD13-GD17). The results showed that the rates of fetal IUGR were markedly increased only in the mice exposed to FEN on GD13-GD17 but not in the mice exposed to FEN on GD7-GD12 or GD0-GD6. Further analysis showed that the blood sinusoid area in the placental labyrinth layer was reduced in the mice exposed to FEN on GD13-GD17. In addition, CD34+ microvessel density in the labyrinthine region was decreased in the male and female fetuses whose mothers were exposed to FEN on GD13-GD17. Mechanistic analysis found that the glutathione level was decreased in the FEN-exposed placentas. In contrast, the levels of 3-nitrotyrosine and malondialdehyde, two oxidative stress markers, were increased in FEN-exposed placentas. Heme oxygenase-1, inducible nitric oxide synthase, catalase and peroxiredoxin-3, which are antioxidant enzymes, were upregulated in the FEN-exposed placentas. The present study suggests that the late gestational stage is a critical time window of FEN-induced fetal IUGR. Placental oxidative stress may be, at least partially, involved in the process of FEN-induced placental damage and fetal IUGR. Highlights • The late gestational stage is a critical time window of FEN-induced fetal IUGR. • Placental damage is induced by FEN expoure. • Placental oxidative stress is, at least partially, involved in the process of FEN-induced fetal IUGR. [ABSTRACT FROM AUTHOR]

The field experiment conducted in the farm at the Department of Agricultural Entomology, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola during kharif 2018-2019 evaluated some insecticides along with botanicals and fungicides in okra. There were 15 treatments and two replications, with a view to evaluate and assess the compatibility of insecticides, botanicals and fungicides against leaf hopper Amrasca biguttula biguttula (Ishida). The results revealed that lambda-cyhalothrin 5%EC @1.33 ml/ l followed by fenvalerate 20%EC @2 ml/ l, pyriproxyfen 5%EC+ fenpropathrin 15%EC @1 ml/ l and lambda-cyhalothrin 5%EC + dashparni extract 15% @1.33 ml+ 12.5 ml/ l are effective. [ABSTRACT FROM AUTHOR]

Fenvalerate (FV) is widely used in aquaculture because of their broad spectrums and high efficiency. However, little is known regarding the elimination of FV influenced by environment factors in aquaculture water, especially its cis-trans isomers (cis-FV and trans-FV). In the present study, factors influencing the aquaculture environment (open type, temperature, pH and light) were selected, and the elimination dynamics of FV and its cis-trans isomers in aquaculture water using orthogonal experiments were investigated. The results showed that the half-life and elimination rate range of FV were 4.75-11.95 days and 65-93%, respectively, while those of trans-FV were 4.60-11.82 days and 67-93% and those of cis-FV were 4.94-12.04 days and 64-92%, respectively. The elimination rate of trans-FV was better than that of cis-FV. Additionally, analysis of variance (ANOVA) of the orthogonal experimental data indicated that the environmental factors of open type, temperature, and pH significantly influenced the elimination rate of cis- and trans-FV (P < 0.05), that is, in the aquaculture season, high temperature and pH facilitate to eliminate FV. This study would improve our understanding of natural degradation associated with FV and guide safe to use associated with pesticide in aquaculture. [ABSTRACT FROM AUTHOR]

The use of pesticides in agriculture can make their way into the earth and wash into the amphibian system causing ecological stress. This study aims to understand the changes occurring in gill tissues as a result of fenvalerate exposure using Fourier-transform infrared spectroscopy. The intensity ratio of the selected bands I1545/I1657, I2924/I2853, and I1045/I1545 measures changes in proteins, lipids, and carbohydrates. Curve-fitting analysis was performed in the selected band region to analyze the quantitative changes of proteins, lipids, and carbohydrates. The band area ratio of CH3/asCH2+ sCH2 shows the absence of a long chain of fatty acids due to fenvalerate treatment. The band area ratio of asCH2/sCH2 increases for higher sublethal concentrations, which shows the lower disorder of lipid acyl chain flexibility. A decrease in lipids was found in lower sublethal concentrations. The secondary structure of proteins affirms β sheet development. Carbohydrate metabolism of gill tissues demonstrates a decrease in glycogen contents. A further decrease in glycogen content and an increase in lactic acid were observed when presented to a fenvalerate concentration. PCA plots indicate distinct variations among the biochemical parameters of the gill tissues. This study provides a quantitative examination of assessing pesticide toxicity in aquatic environments. [ABSTRACT FROM AUTHOR]

Strain CY-012 isolated from garden soil sprayed with pyrethroid pesticide was able to efficiently degrade fenvalerate. The bacterium was identified as Bacillus licheniformis based on its morphology, physiological and biochemical characteristics, and 16S ribosomal DNA gene analysis. Response surface methodology analysis showed that the optimum conditions for fenvalerate degradation were fenvalerate concentration of 44.04 mg L−1, pH 7.48, and ferric chloride concentration of 0.051% (w/v). Under these conditions, approximately 80.07% of fenvalerate was degraded within 60 h of incubation. Five metabolic compounds, including α-isopropyl-4-chlorobenzene acetic acid, 4-chlorobenzene acetic acid, 3-phenoxybenzyl alcohol, phenol and benzoic acid were detected during fenvalerate degradation and identified by gas chromatography-mass spectrometry. A possible degradation pathway of fenvalerate was proposed based on these identified metabolites. The results indicated that strain CY-012 could potentially be used to eliminate environmental contamination with pyrethroid insecticides. [ABSTRACT FROM AUTHOR]

Fenvalerate (Fen), a synthetic pyrethroid insecticide, is widely used in agricultural, domestic and veterinary applications. Fen induces abnormal cell proliferation and apoptosis, which are linked to its hazardous effects. However, this view is controversial and the underlying molecular mechanisms remain elusive. In the present study, the effects of Fen on cadmium (Cd)-induced apoptosis and the associated molecular mechanisms were investigated in human myeloid leukemia U937 cells. U937 cells were treated with 50 μ m cadmium chloride (CdCl2) with or without Fen pretreatment at 1-50 μ m. Apoptosis was evaluated by externalization of phosphatidylserine on the plasma membrane. The expression levels of apoptosis-related proteins, including Bcl-2 family members were determined by western blot analysis. The results revealed that pretreatment with Fen at 20 μ m for 12 hours significantly inhibited Cd-induced apoptosis. Decreased expression of pro-apoptotic Bcl-2 family proteins (Noxa and Bid) and increased expression of anti-apoptotic proteins (Bcl-xL, Mcl-1 and XIAP) were observed after combined treatment with Fen and CdCl2. Phosphorylation of ERK and AKT was increased, while phosphorylation of JNK was decreased by the combined treatment, compared with CdCl2 treatment alone. In conclusion, Fen decreased apoptotic sensitivity induced by Cd in U937 cells. This effect was associated with activation of ERK and AKT, suppression of JNK and changes in expression of Bcl-2 family proteins and XIAP. The present findings suggest a potential influence of Fen on Cd toxicity via suppression of apoptosis. Fen decreased apoptotic sensitivity induced by Cd, and thus it may contribute carcinogenic risk and influence on cancer therapy. [ABSTRACT FROM AUTHOR]

Pyrethroids are synthetic organic insecticides with low mammalian toxicity that are widely used in both rural and urban areas worldwide. After entering the natural environment, pyrethroids circulate among the three phases of solid, liquid, and gas and enter organisms through food chains, resulting in substantial health risks. This review summarized the available studies on pyrethroid residues since 1986 in different media at the global scale and indicated that pyrethroids have been widely detected in a range of environments (including soils, water, sediments, and indoors) and in organisms. The concentrations and detection rates of agricultural pyrethroids, which always contain α-cyanogroup (α-CN), such as cypermethrin and fenvalerate, decline in the order of crops > sediments > soils > water. Urban pyrethroids (not contain α-CN), such as permethrin, have been detected at high levels in the indoor environment, and 3-phenoxybenzoic acid, a common pyrethroid metabolite in human urine, is frequently detected in the human body. Pyrethroid pesticides accumulate in sediments, which are a source of pyrethroid residues in aquatic products. [ABSTRACT FROM AUTHOR]

Background: Pyrethroids have prominently known for their insecticidal actions worldwide, but recent reports as anticancer and antiviral applications gained a lot of interest to further understand their safety and immunotoxicity. Objective: This encouraged us to carry out our present study to evaluate the interactions of pyrethroids toward adaptive immune cell receptors. Materials and Methods: Type 1 and Type 2 pyrethroids were tested on T (CD4 and CD8) and B (CD28 and CD45) immune cell receptors using Maestro 9.3 (Schrödinger, LLC, Cambridge, USA). In addition, top-ranked tested ligands were too explored for toxicity prediction in rodents using ProTOX tool. Results: Pyrethroids (specifically type 2) such as fenvalerate (-5.534 kcal/mol: CD8), fluvalinate (-4.644 and - 4.431 kcal/mol: CD4 and CD45), and cypermethrin (-3.535 kcal/mol: CD28) have outcome in less energy or more affinity for B-cell and T-cell immune receptors which may later result in the immunosuppressive and hypersensitivity reactions. Conclusion: The current findings have uncovered that there is a further need to assess the Type 2 pyrethroids with wet laboratory experiments to understand the chemical nature of pyrethroid-induced immunotoxicity. [ABSTRACT FROM AUTHOR]

Simple and sensitive spectrophotometric scheme was described for the determination of fenvalerate in environmental samples. The scheme was based on the hydrolysis of 1 N of 5 mL NaOH to form cyanohydrin. The cyanohydrin is reacted with bromine and pyridine to form glutaconic aldehyde, which is then coupled with p-Dimethylaminobenzaldehyde to give yellow dye having maximum absorbance at 440 run. Beer's law is obeyed over the concentration range of 0.6-6.2 µg in a final solution volume of 25 mL. The molar absorptivity of the colored system is 3.84x104 L mol-1cm-1 and Sandell's sensitivity is 2.4x10-3 µg cm-2. The reproducibility assessed by carrying out seven days replicate analysis of a solution containing 0.6 µg of fenvalerate in a final solution volume of 25 mL. The standard deviation and relative standard deviation for the absorbance value were found to be ± 3.4x10-3 and 1.5% respectively. The proposed scheme is sensitive and free from the interference of other toxicants. The analytical parameters were optimized and the scheme was applied to the determination of fenvalerate in environmental samples. [ABSTRACT FROM AUTHOR]

Fenvalerate (Fen), a widely used pesticide, is known to impair male reproductive functions by mechanisms that remain to be elucidated. Recent studies indicated that circadian clock genes may play an important role in successful male reproduction. The aim of this study was to determine the effects of Fen on circadian clock genes involved in the biosynthesis of testosterone using TM3 cells derived from mouse Leydig cells. Data demonstrated that the circadian rhythm of testosterone synthesis in TM3 cells was disturbed following Fen treatment as evidenced by changes in the circadian rhythmicity of core clock genes (Bmal1, Rev-erbα, Rorα). Further, the observed altered rhythms were accompanied by increased intracellular Ca2+levels and modified steroidogenic acute regulatory (StAR) mRNA expression. Thus, data suggested that Fen inhibits testosterone synthesis via pathways involving intracellular Ca2+and clock genes (Bmal1, Rev-Erbα, Rorα) as well as StAR mRNA expression in TM3 cells. [ABSTRACT FROM PUBLISHER]

Synthetic pyrethroid-fenvalerate-is one of the most widespread toxic pollutants and has adverse effect on living systems. However, little is known about its biotransformation mechanism in different microorganisms. To elucidate the pathway that might be involved in the catabolism of fenvalerate, we used Bacillus flexus strain XJU-4 (3-nitrobenzoate degrading organism) as an ideal fenvalerate degrading bacterium. Thin layer chromatography, high performance liquid chromatography and gas chromatography-mass spectrometry analysis results revealed that 3-phenoxybenzoate, protocatechuate, and catechol are the three main by-products of fenvalerate metabolism. Additionally, the bacterial cell-free enzymes showed the activities of fenvalerate hydrolyzing esterase, 3-phenoxybenzaldehyde dehydrogenase, 3-phenoxybenzoate dioxygenase, phenol hydroxylase, protocatechuate 2,3-dioxygenase and catechol-2,3-dioxygenase. Thus, in strain XJU-4, protocatechuate and catechol were further metabolized through meta-cleavage pathway. Moreover, laboratory-scale soil experiments results suggest that B. flexus strain XJU-4 is a suitable contender for bioremediation of pyrethroid fenvalerate-contaminated sites. [ABSTRACT FROM AUTHOR]

A high-surface-area nanoporous carbon (NPC) has been successfully synthesized by using the metal-organic framework ZIF-90 as both the template and precursor together with furfuryl alcohol as a secondary carbon source. The prepared ZIF-90 templated NPC (ZIF-90-NPC) was then coated onto a stainless steel wire by a simple physical adhesion approach to prepare solid-phase microextraction (SPME) fiber. By coupling the ZIF-90-NPC coated fiber-based SPME with gas chromatography-microelectron capture detection (GC-μECD), the developed method gave a large enhancement factor (984-2869), low limit of detection (0.1–0.5 ng g −1 ) and good linearity (0.3–50 ng g −1 ) for the determination of some pyrethroid pesticides (bifenthrin, fenpropathrin, cyhalothrin, permethrin, cyfluthrin, flucythrinate, fenvalerate and deltamethrin) from different fruits and vegetables. The relative standard deviations (RSDs) for six replicate extractions of the pyrethroids by the ZIF-90-NPC coated fiber ranged from 4.3% to 8.0%. The recoveries of the spiked pyrethroids (5 ng g −1 and 20 ng g −1 ) from fruit and vegetable samples were in the range of 88.0–104.0% and 86.0–103.5% with the RSDs ranging from 4.8% to 12.9% and 5.0–10.8%, respectively. Besides, the ZIF-90-NPC coated fiber was stable enough for 100 extraction cycles without a significant loss of extraction efficiency. The method was successfully applied to the determination of the pyrethroids in fruit and vegetable samples. [ABSTRACT FROM AUTHOR]

In this study, carboxylic multiwall carbon nanotubes (CMNTs) were used as an adsorbent for removing fenvalerate as a toxic insecticide from solution through batch experiments. The influence of four independent parameters of HCl, initial fenvalerate concentration, CMNTs dosage, and contact time on the fenvalerate adsorption process was investigated. Raman spectroscopy and thermogravimetric analysis confirmed that the adsorption and maximum adsorption capacity (40.0 mg g) showed high adsorption potential of the proposed sorbent. The kinetic, isothermic, and thermodynamic of fenvalerate adsorptionon CMNTs were evaluated to better understand this environmental friendly adsorption strategy. A pseudo-first-order kinetic described very well the experimental data of the adsorption kinetics. The experimental data found to be properly fitted to Freundlich model, which indicates that the sorption takes place on a heterogeneous material. The thermodynamic results showed the negative value of the standard free energy ( $$\Delta G^{0}$$ ) and standard enthalpy change ( $$\Delta H^{0}$$ ) showing an exothermic and spontaneous system. Repeated availability of adsorbent investigated and SEM and HRTEM of reused adsorbent showed stability and non-aggregatable attributes of CMNTs. [ABSTRACT FROM AUTHOR]

Objective(s): Particularly in developing countries, selenium and/or iodine deficiencies are encountered and use of pesticides in agriculture are not well-controlled. Fenvalerate is a pyrethroid insectide used in agriculture and has applications against a wide range of pests. This study was designed to evaluate the effects of fenvalerate on hepatic and cerebral xenobiotic metabolizing enzyme activities in the presence of iodine and/or selenium deficiency on a rat model. Materials and Methods: Iodine and/or selenium deficiency was induced by feeding three-week-old Wistar rats with a diet containing <0.005 mg selenium kg-1, and/or administering 1% sodium perchlorate in drinking water for 7 weeks. Test groups received fenvalerate (100 mg kg-1 BW IP) for the last 7 days. Hepatic and cerebral microsomal aniline hydroxylase (CYP2E1) and cytosolic glutathione S-transferase (GST) activities were determined. Besides, hepatic NADPH-cytochrome P450 reductase (P450R), ethoxyresorufin O-deethylase (EROD, CYP1A1/1A2) and penthoxyresorufin O-depenthylase (PROD, CYP2B1/2B2), activities were also measured. Results: Fenvalerate had a general inductive effect on the hepatic and cerebral xenobiotic metabolizing enzyme activities. Moreover, enzyme activities were also altered by iodine and/or selenium deficiency, but the effects seemed to be enzyme- and tissue-specific. Conclusion: The inductive effect of fenvalerate, particularly in high dose exposures, may change the metabolism of several xenobiotics, including drugs, as well as endogenous substrates. The effects may vary depending on the selenium and/or iodine status of individual. [ABSTRACT FROM AUTHOR]

A novel supramolecular solvent-based microextraction followed by high-performance liquid chromatography with ultraviolet detection method has been developed for the extraction and determination of two pyrethroid analytes, cyhalothrin and fenvalerate, in water and soil samples. The liquid-liquid-phase separation of surfactants has been used in analytical extraction. The surfactant-rich phase is a nano-structured liquid, recently named as a supramolecular solvent, generated from the amphiphiles. The alkyl carboxylic acid based supramolecular solvents were introduced before. Coacervates made up of gemini surfactant, consisting of two amphiphilic moieties, were first used as solvent. The effective parameters on extraction (i.e., type of organic solvent, the amount of surfactant and volume of tetrahydrofuran, sample solution pH, salt addition, ultrasonic and centrifugation time) were investigated and optimized. Under the optimum conditions, preconcentration factors of 110 and 145 were obtained for the analytes. The linearity was 0.5-200.0 μg/L with the correlation of determination of ( R2) ≥ 0.9984. The limit of detection of the method was (S/N = 3) 0.2 μg/L, and precisions in the range of 6.3-10.3% (RSDs, n = 5) were obtained. This method has been successfully applied to analyze real samples, and good recoveries in the range of 101.2-108.8% were obtained. [ABSTRACT FROM AUTHOR]

A series of essential oils oriented ester derivatives have been designed, synthesized and characterized based on the skeleton of fenvalerate. The preliminary bioassay results indicated that some of the newly synthesized compounds showed better insecticidal activities against Pyrausta nubilalis and Heliothis armigera than that of the control trans-prallethrin chloride. [ABSTRACT FROM AUTHOR]

GluR2, an α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor subunit, plays important roles in neuronal survival. We previously showed that exposure of cultured rat cortical neurons to several chemicals decreases GluR2 protein expression, leading to neuronal toxicity. Methoxychlor, the bis-p-methoxy derivative of dichlorodiphenyltrichloroethane, and fenvalerate, a synthetic pyrethroid chemical, have been used commercially as agricultural pesticides in several countries. In this study, we investigated the effects of long-term methoxychlor and fenvalerate exposure on neuronal glutamate receptors. Treatment of cultured rat cortical neurons with 1 or 10 μM methoxychlor and fenvalerate for 9 days selectively decreased GluR2 protein expression; the expression of other AMPA receptor subunits GluR1, GluR3, and GluR4 did not change under the same conditions. Importantly, the decreases in GluR2 protein expression were also observed on the cell surface membrane where AMPA receptors typically function. In addition, both chemicals decreased neuronal viability, which was blocked by pretreatment with 1-naphtylacetylspermine, an antagonist of GluR2-lacking AMPA receptors, and MK-801, an N-methyl-d-aspartate (NMDA) receptor antagonist. These results suggest that long-term exposure to methoxychlor and fenvalerate decreases GluR2 protein expression, leading to neuronal death via overactivation of GluR2-lacking AMPA and NMDA receptors. [ABSTRACT FROM AUTHOR]

The toxic effects of pesticides and minerals have been explored in different species, but still there is paucity of information regarding their combined toxicological effects. The present investigation reports oxidative stress induced by oral subacute exposure to fenvalerate (1 mg/kg) and sodium nitrate (20 mg/kg) alone, as well as in combination daily for 21 days in buffalo calves. Fenvalerate exposure produced significant elevation in lipid peroxidation (LPO), glutathione peroxidase (GPx), while it produced significant decline in blood glutathione (GSH) levels, superoxide dismutase (SOD) and catalase (CAT). No significant alteration was evidenced in nitric oxide (NOx) levels. Oral exposure to sodium nitrate produced significant inclination in LPO and NOx, while on the other hand significant depreciation in SOD and CAT with no significant change in GPx activity. Combined exposure to fenvalerate and sodium nitrate produced severe effects with an appreciably more prominent elevation in extent of LPO and decline in blood GSH levels. [ABSTRACT FROM AUTHOR]

The low aqueous solubility and chiral complexity of synthetic pyrethroids, together with large differences between isomers in their insecticidal potency, have hindered the development of meaningful assays of their metabolism and metabolic resistance to them. To overcome these problems, Shan and Hammock (2001) [7] therefore developed fluorogenic and more water-soluble analogues of all the individual isomers of the commonly used Type 2 pyrethroids, cypermethrin and fenvalerate. The analogues have now been used in several studies of esterase-based metabolism and metabolic resistance. Here we test the validity of these analogues by quantitatively comparing their hydrolysis by a battery of 22 heterologously expressed insect esterases with the hydrolysis of the corresponding pyrethroid isomers by these esterases in an HPLC assay recently developed by Teese et al. (2013) [14]. We find a strong, albeit not complete, correlation (r = 0.7) between rates for the two sets of substrates. The three most potent isomers tested were all relatively slowly degraded in both sets of data but three esterases previously associated with pyrethroid resistance in Helicoverpa armigera did not show higher activities for these isomers than did allelic enzymes derived from susceptible H. armigera . Given their amenability to continuous assays at low substrate concentrations in microplate format, and ready detection of product, we endorse the ongoing utility of the analogues in many metabolic studies of pyrethroids. [ABSTRACT FROM AUTHOR]

Context: Insecticides are used to control pests. Cypermethrin and fenvalerate are widely used pirethroid insecticides in the world. Rosa canina L. (Rosaceae) is used as a traditional medicinal plant against viral infections and disorders of the kidneys and urinary tract due to its high vitamin C level. Objective: The genotoxic effects of cypermethrin and fenvalerate were examined with the micronucleus (MN) test. Then, we determined the ability of the water (RCwtr) and ethanol (RCeta) extracts of rosehip ( R. canina) to overcome the possible genotoxic effects of the insecticides. Materials and methods: Preliminary studies determined that the application concentrations were 20, 30, 40, and 50 ppm for cypermethrin, 25, 50, 75, and 100 ppm for fenvalerate, and 100 ppm for rosehip extracts. DMSO (dimethyl sulphoxide) (1%) and 1 mM EMS (ethyl methanesulfonate) were used as negative and positive control groups, respectively. The application groups belonging to insecticides and plant extracts were added to culture tubes including chromosome B medium and peripheral blood for MN test. Results: The MN frequencies were found 0.725 in the negative control group, 2.700 in the positive control groups, 1.275 in the highest application group of cypermethrin, and 1.600 in the highest application group of fenvalerate. The MN frequencies in cypermethrin + RCwtr, cypermethrin + RCeta, fenvalerate + RCwtr, and fenvalerate + RCeta application groups were, respectively, determined as 1.000, 1.075, 1.225, and 1.275. Conclusion: According to the results, cypermethrin and fenvalerate have genotoxic effects, the water and ethanol extracts of rosehip reduced the genotoxicity of the both insecticides. [ABSTRACT FROM AUTHOR]

The increasing resistance level of insect pest species is a major concern to agriculture worldwide. The cotton bollworm, Helicoverpa armigera , is one of the most important pest species due to being highly polyphagous, geographically widespread, and resistant towards many chemical classes of insecticides. We previously described the mechanism of fenvalerate resistance in Australian populations conferred by the chimeric cytochrome P450 monooxygenase CYP337B3 , which arose by unequal crossing-over between CYP337B1 and CYP337B2 . Here, we show that this mechanism is also present in the cypermethrin-resistant FSD strain from Pakistan. The Pakistani and the Australian CYP337B3 alleles differ by 18 synonymous and three nonsynonymous SNPs and additionally in the length and sequence of the intron. Nevertheless, the activity of both CYP337B3 proteins is comparable. We demonstrate that CYP337B3 is capable of metabolizing cypermethrin ( trans - and especially cis -isomers) to the main metabolite 4'-hydroxycypermethrin, which exhibits no intrinsic toxicity towards susceptible larvae. In a bioassay, CYP337B3 confers a 7-fold resistance towards cypermethrin in FSD larvae compared to susceptible larvae from the Australian TWB strain lacking CYP337B3. Linkage analysis shows that presence of CYP337B3 accounts for most of the cypermethrin resistance in the FSD strain; up-regulation of other P450s in FSD plays no detectable role in resistance. The presence or absence of CYP337B3 can be easily detected by a simple PCR screen, providing a powerful tool to rapidly distinguish resistant from susceptible individuals in the field and to determine the geographical distribution of this resistance gene. Our results suggest that CYP337B3 evolved twice independently by unequal crossing-over between CYP337B2 and two different CYP337B1 alleles. [ABSTRACT FROM AUTHOR]

This study was undertaken to determine the present status of pesticide residues in breast milk from Punjab. A total of 127 breast milk samples were analyzed and pesticide residues were detected in 25 % of the milk samples. Residues of cyfluthrin, fenvalerate, cypermethrin, profenophos, γ-HCH, β-HCH, chlorpyriphos, monocrotophos, p,p′ DDE and phosalone were detected with mean levels of 63.04, 11.69, 3.63, 2.66, 2.64, 2.29, 1.91, 1.63, 0.56 and 0.29 ng g, respectively. Cyfluthrin was leading pesticide detected in breast milk contributing 31.28 % to the total residue load. It was observed that the residue levels were decreasing with increase in parity and age of mother and cyfluthrin had highest mean concentration of 90.63 ng g in the first parity and 21.11 ng g in youngest age group. Residue levels were higher in urban population than the rural population although, statistically non-significant difference was found between the two ( p > 0.05). [ABSTRACT FROM AUTHOR]

Ultrasound-assisted solvent extraction (UASE) combined with dispersive liquid–liquid microextraction based on the solidification of floating organic drop (DLLME-SFO) has been developed for extraction and determination of fenvalerate from tomato samples. Fenvalerate was determined by high-performance liquid–liquid chromatography-ultraviolet detector. Effects of parameters such as type and volume of extraction solvent in the UASE stage, sonication time, type and volume of extraction solvent and disperser solvent in the DLLME-SFO stage, salt addition and pH effect on extraction were studied and optimized. Under the optimum conditions, the calibration graph was linear in the range of 5–500 µg kg−1 with a detection limit of 0.6 µg kg−1. The relative standard deviation for five replicate measurements of 100 µg kg−1 of fenvalerate was 6.5%. The relative recovery of fenvalerate in different tomato samples at a spiking level of 10, 20 and 50 µg kg−1 is in the range of 93.5–108%. The obtained results show that UASE–DLLME-SFO is a sensitive, fast and simple method for the determination of fenvalerate in tomato samples. [ABSTRACT FROM PUBLISHER]

The present study investigated haematological alterations induced by oral subacute exposure to fenvalerate, nitrate and their combination in the domestic buffalo, Bubalus bubalis. Fenvalerate exposure produced significant declines in haemoglobin (Hb), total leukocyte count (TLC), total erythrocyte count (TEC) and mean corpuscular haemoglobin concentration (MCHC), and a corresponding elevation in mean corpuscular volume (MCV). Following oral exposure to sodium nitrate, significant declines in blood Hb, TLC, TEC, MCH and MCHC, and a significant elevation in MCV occurred. Combined exposure to fenvalerate and sodium nitrate produced severe effects with an appreciably more prominent decline in Hb, TLC, TEC and MCHC and a significant elevation in MCV. The percentage of methaemoglobin was observed to follow an elevating trend in animals exposed to sodium nitrate alone (0.69 %-13.8 %) and in combination with fenvalerate (0.75 %-13.7 %). [ABSTRACT FROM AUTHOR]

The African bollworm,Helicoverpa armigera(Hübner), and the cotton red spider mite,Tetranychusspp., are important pests of cotton in Zimbabwe. A study to assessH. armigeraresistance to fenvalerate 20 EC (Cyano (3-phenoxyphenyl) methyl 4-chloro-α-(1-methylethyl)benzene acetate) andTetranychusspp. resistance to amitraz 20 EC (n’-(2,4-dimethylphenyl)-n-[[(2,4-dimethylphenyl)imino]methyl]-n-) was conducted at the Cotton Research Institute (CRI) during the 2005/06 cotton-growing season. Field populations ofH. armigeraandTetranychusspp. were collected from some of Zimbabwe’s major cotton-growing areas of Sanyati, Umguza, Chisumbanje, Chinhoyi and the CRI in Kadoma and exposed to bioassays. The African bollworm leaf disc technique and the red spider mite attached leaf-dipping technique were used to assess responses of the African bollworm and red spider mite to the pesticides. Susceptible laboratory populations served as the standard populations and their responses were compared with those of the field populations. The graphical method and MSTAT-C probit analysis computer program were used to calculate LC50values. Although the CRI field population, used as a reference population for the registration ofH. armigerainsecticides, had the highest LC50value (graphical = 0.000100000; MSTAT-C = 0.000088195) compared with all the other field populations, overall log-dose probit bioassays on all field-collected strains of the bollworm showed no resistance to the pyrethroid (RFs = 0.04–0.54-fold).Tetranychusspp. showed very low levels of resistance (RFs = 1.26–2.00-fold). Continuous monitoring of major cotton pests, especiallyH. armigeraandTetranychusspp., from all cotton districts of Zimbabwe is vital for early detection of resistance development. [ABSTRACT FROM AUTHOR]

Aim: Evaluation of combined effect of fenvalerate and nitrate on biochemical parameters in buffalo calves. Materials and Methods: Sixteen male buffalo calves were divided into four groups of four calves each. Group I receiving no treatment served as the control. Group II and III animals were orally administered with fenvalerate (1.0 mg/kg/day) and sodium nitrate (20 mg/kg/day), respectively, for 21 consecutive days and were kept as positive control. Group IV animals were co-administered with fenvalerate and sodium nitrate at the above dose rates for 21 consecutive days. Biochemical parameters including Aspartate aminotransferase (AST), Alkaline phosphatase (ALP), Gamma-glutamyl transpeptidase (GGT), Lactate dehydrogenase (LDH), Glucose, Total protein, Albumin, Cholesterol, Blood urea nitrogen (BUN) and Creatinine were determined on 0, 3, 7, 10, 14, 17 and 21 day of treatment. Estimation of these parameters was also done on 7th day of posttreatment period. Results: Co-administration of fenvalerate and sodium nitrate produced significant increase in the plasma levels of AST, ALP, GGT, LDH, glucose, BUN, cholesterol and creatinine while significant decrease in the plasma levels of total proteins was observed. No significant alteration was observed in albumin levels. Extent of organ damage as evidenced by biochemical alterations was more pronounced in calves exposed to combination of fenvalerate and sodium nitrate as compared to their individual exposures. Conclusion: Fenvalerate and sodium nitrate co-administration potentiates the toxicological injury produced, in comparison to their individual exposure. [ABSTRACT FROM AUTHOR]

The glutathione-coated CdTe quantum dots (QDs) were synthesized in a paper. After purification, the QDs were coupled with monoclonal antibody to fight against fenvalerate. The conjugates had the same emission wavelength as that of QDs. The excitation wavelength and emission wavelength of the conjugates were determined to obtain the highest signal-to-noise ratio. After the antibody concentration optimization, the fluorescence-linked immunoassay method was developed. The method used the QDs as the signal to quantify the fenvalerate. Compared with the enzyme-linked immunosorbent assay (ELISA), it saved more than 1 h and decreased the false-positive rate using the specified emission wavelength of QDs. The 50% inhibitory concentration (IC50) of the method was 0.28 µg mL−1. The detection limit was 25 ng mL−1and the linear range was 60 ng mL−1–3.83 µg mL−1. Via preliminary application, fenvalerate residues in spiked samples were determined. The recovery of fenvalerate in water samples ranged from 84.5% to 96.2% and that in vegetables ranged from 72.5% to 125.7%. It was a rapid detection of the fenvalerate residue in environment and vegetables. [ABSTRACT FROM PUBLISHER]

Abstract: To establish the use of Metaphire posthuma as a sensitive test model for ecotoxicological studies, acute toxicity testing of carbaryl, carbofuran, cypermethrin and fenvalerate on Eisenia fetida and Metaphire posthuma were carried out. Two different types of bioassays, contact filter paper toxicity and soil toxicity bioassays were used to determine LC50 values for these insecticides. Among the tested chemicals, carbofuran was the most toxic to both the earthworm species. In paper contact method, 72h-LC50 values of carbofuran in M. posthuma and E. fetida were found to be 0.08μg/cm2 and 1.55μg/cm2 respectively while in soil test, 14-d LC50 values were 0.49mg/kg and 21.15mg/kg respectively. On comparing the toxicity data of these chemicals for both the earthworm species, M. posthuma was found to be more sensitive than E. fetida. Based on the acute toxicity data, the order of toxicity of insecticides in both the test procedures was carbofuran>cypermethrin>carbaryl>fenvalerate for M. posthuma whereas for E. fetida it was carbofuran>carbaryl>fenvalerate>cypermethrin. Morphological changes also appeared in the organisms exposed to these chemicals which were more pronounced in M. posthuma at lower concentrations than E. fetida in both the test procedures. The results of the present study advocates the use of M. posthuma for ecotoxicity studies, being a more sensitive and reliable model than E. fetida. Based on the data on partial atomic charges, structural features and spectroscopic studies on carbaryl and carbofuran, a possible mechanism of toxicity of carbamate insecticides in earthworm was proposed. [Copyright &y& Elsevier]

BACKGROUND Previous studies in our laboratory showed that cytochrome P450 CYP6B7 plays a critical role in a Handan fenvalerate resistant strain ( HDFR) of Helicoverpa armigera. As an important component of P450 enzyme systems, cytochrome P450 reductase ( CPR) plays an essential role in transferring electrons from NADPH to the P450-substrate complex. However, little information about CPR in H. armigera ( HaCPR) has been reported. RESULTS A full-length cDNA (3525 bp) of HaCPR was cloned. The open reading frame of the HaCPR gene encoded 687 amino acids and shared 27.87-95.21% identities with other known CPRs. Bioinformatic analysis showed that HaCPR is a transmembrane protein with Mw of 77.4 kDa and contains conserved features. The results of real-time quantitative polymerase chain reaction showed that the expression level of HaCPR mRNA was 1.84-fold higher in midgut of 5th instars of the Handan susceptible strain than that in pupae, and the level in the midgut of HDFR strain was 2.02-fold higher than that of the Handan susceptible strain. The levels of HaCPR mRNA were induced by phenobarbital at concentrations of 2 and 4 mg g−1, which enhanced 5.20- and 17.45-fold, respectively, compared to that of the control after 48 h of phenobarbital treatment. CONCLUSIONS The results indicate that HaCPR is important for the development of H. armigera and may play an essential role in the P450-mediated insecticide resistance of H. armigera to fenvalerate. © 2013 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Highlights: [•] EIS was employed for the first time employed to determine fenvalerate. [•] Pre-treatment for the detection is simple in operation with this technique. [•] This method is label-free with high sensitivity and selectivity, rapidity and low cost. [ABSTRACT FROM AUTHOR]

Fenvalerate (Fen), a synthetic pyrethroid insecticide, has been shown to have adverse effects on male reproductive system. Thus, the aim of the present study was to elucidate whether these adverse effects are passed from exposed male mice to their offspring. Adult male mice received Fen (10 mg/kg) daily for 30 days and mated with untreated females to produce offspring. Fenvalerate significantly changed the methylation status of angiotensin I-converting enzyme (Ace), forkhead box O3 (Foxo3a), huntingtin-associated protein 1 (Hap1), nuclear receptor subfamily 3 (Nr3c2), promyelocytic leukemia (Pml), and Prostaglandin F2 receptor negative regulator (Ptgfrn) genes in paternal mice sperm genomic DNA. Further, Fen significantly increased sperm abnormalities; serum testosterone and estradiol-17ß level in adult male (F0) and their male offspring (F1). Further, paternal Fen treatment significantly increased the length of estrous cycle, serum estradiol-17ß concentration in estrus, and progesterone levels in diestrus in female offspring (F1). These findings suggest that adverse effects of paternal Fen exposure on reproductive functions can be seen not only in treated males (F0) but also in their offsprings. [ABSTRACT FROM PUBLISHER]

The aim of the present study is to find the toxic effect of fenvalerate, a synthetic pyrethroid pesticide on the gill of a teleost cat fish, Heteropneustes fossilis pesticide after its characterization by Scanning Electron Microscopy (SEM). Three different sublethal doses of fenvalerate dissolved in acetone were used to find the damage on the gills. Fenvalerate found toxic to all the doses given to the test fish. [ABSTRACT FROM AUTHOR]

Oocyte maturation is transformation of oocytes into a fertilizable egg. This study examined the effects of four classes of chemicals: 1) acephate (organophosphate); 2) atrazine (herbicide); 3) cypermethrin and fenvalerate (synthetic pyrethroids); and 4) carbaryl (carbamate) on in vitro germinal vesicle breakdown (GVBD) of Euphlyctis cyanophlyctis oocytes. Follicles were isolated and defolliculated from surgically removed ovaries of E. cyanophlyctis and exposed to either progesterone (1 μM/mL) or graded concentrations (1, 5, 10, 15, and 20 μg/mL) of test chemicals. GVBD was evident by the presence of a white spot in the animal pole as well as the absence of germinal vesicles in sectioned heat-fixed oocytes. Percent GVBD was scored every 4 hours until 24 hours. Progesterone induced 77–84% GVBD, compared to 29–33% in controls, at 24 hours. Acephate induced 46–67% GVBD, whereas atrazine elicited 58–77% of GVBD. In cypermethrin or carbaryl- or fenvalerate-exposed oocytes, GVBD was limited to 22–28, 17–29 and 18–24%, respectively. The study infers that some chemical contaminants in the aquatic system may interfere with GVBD in amphibians. Because oocyte maturation is a prerequisite for the production of fertilizable eggs, any alteration in this process potentially impairs the fecundity of females. [ABSTRACT FROM AUTHOR]

A fenvalerate-degrading bacterial strain F-7 was isolated from long-term contaminated sludge. Based on morphological, physiological and biochemical characterization, and phylogenetic analysis of 16S rRNA gene sequence, strain F-7 was identified asSphingomonassp. The bacterium could utilize fenvalerate as the sole source of carbon. An amount measuring 100 mg L−1fenvalerate was completely degraded within 72 h and 3-phenoxybenzoic acid (3-PBA) was detected as a major metabolite. The result indicates thatS. sp. F-7 might metabolize fenvalerate by hydrolysis of carboxylester linkage. It was capable of degrading permethrin, fenpropathrin, beta-cypermethrin, cyhalothrin, deltamethrin, bifenthrin and 3-PBA. Further studies demonstrated that the strain was multi-resistant to heavy metals and antibiotics. In addition, degradative enzymes involved were confirmed as intracellular distributed and constitutively expressed. Furthermore, application of the strain was found to accelerate the removal of fenvalerate in soil. This is the first report of fenvalerate degrading strain isolated fromS.sp. These results might help with future research in better understanding of pyrethroid biodegradation and highlightS.sp. F-7 might have potential for practical application in bioremediation of fenvalerate-contaminated sites. [ABSTRACT FROM PUBLISHER]

Abstract: Resmethrin, phenothrin, and fenvalerate are the synthetic pyrethroids that have been used widely against groundling or flying insect pests both indoors and outdoors. In this study, the heterogeneous reactions of the three pyrethroid particles with NO3 radicals are investigated with a mixed-phase relative rate method. The reactions are performed in a reaction chamber equipped with a vacuum ultraviolet photoionization aerosol time-of-flight mass spectrometer (VUV-ATOFMS) and an atmospheric gas analysis mass spectrometer. The uptake coefficients of NO3 radicals on resmethrin, phenothrin, and fenvalerate particles are ∼0.20, 0.04, and 0.03 respectively, calculated with a spherical shell model. And the atmospheric lifetimes of the three pyrethroid particles toward NO3 radicals are estimated to be ∼2.6, 7.5, and 9.3h, respectively. The molecular structures of reaction products and the reaction pathways are suggested based on the measurements of VUV-ATOFMS and off-line GC–MS. [Copyright &y& Elsevier]

Pesticides can significantly harm reproduction in animals and people. Pyrethroids are often used as insecticides, and their toxicity for mammals is considered to be low. However, cypermethrin, deltamethrin and fenvalerate – as potent specific inhibitors of protein phosphatase calcineurin – can influence the meiosis of mammalian oocytes. The objective of this study was to evaluate the effects of these pyrethroids on the in vitro maturation of pig oocytes at different levels of meiotic competence. Under the tested concentrations, cypermethrin, deltamethrin and fenvalerate neither had a significant effect on the viability of oocytes nor did they induce significant degeneration of oocytes. However, these pyrethroids significantly affected meiotic maturation. The effects depended on the stage of meiotic competence of the oocytes. Maturation of growing pig oocytes with partial meiotic competence was induced. On the other hand, in fully grown pig oocytes with full meiotic competence, maturation in vitro was delayed. The specificity of these effects was further supported by the same effect of non-pyrethroidal inhibitors of calcineurin – cyclosporin A or hymenistatin I – on the maturation of oocytes with different levels of meiotic competence. However, pyrethroids, which do not inhibit calcineurin – allethrin or permethrin – had no effect on pig oocyte maturation. We demonstrated a significant effect of pyrethroids on the maturation of mammalian oocytes under in vitro conditions. This indicates that exposure to these substances could affect the fertility of people or animals. [ABSTRACT FROM AUTHOR]

Abstract: We have obtained a Helicoverpa armigera strain (MonoR) showing high level resistance to monocrotophos by 15 generations of selection on a weakly resistant field-caught strain. Bioassays using various synergists show a major role for esterases in the resistance, and little if any role for cytochrome P450s or glutathione S-transferases. Biochemical data also show elevated levels of esterase activity in the resistant line. There were also minor differences among our strains in the kinetics of acetylcholinesterase activity and in its susceptibility to monocrotophos inhibition, and sequence comparisons revealed one amino acid substitution in AChE1 but none in AChE2 in the MonoR strain. However the AChE1 substitution does not match any others linked to resistance in this or other species and would be located well away from the enzyme active site, so it may not be causally involved with resistance. Native PAGE shows several individual esterase isozymes are more intensely staining in the resistant line and native Western analysis with an antibody against Clade 1 esterases show that several of these belong to Clade 1 and that their greater staining intensity in MonoR is due to greater amounts of the respective enzymes. Proteomic analysis of gel slices also matches the overexpressed bands with up to six Clade 1 enzymes, with some involvement also from esterases in three other Clades. Two of the isozymes that are overexpressed in MonoR are also overexpressed in a fenvalerate resistant line and proteomic analysis of that line bears out previous proteomics of another fenvalerate resistant line which also implicates Clade 1 isozymes. [Copyright &y& Elsevier]

BACKGROUND: The function of cytochrome P450 proteins (P450s) in the metabolism of a variety of compounds by oxidation and reduction is well elucidated, but its interactions with other electron transfer components in the pyrethroid resistance of insect pests have been a mystery for a long time. In previous studies the authors cloned and characterised CYP6B7 and cytochrome b5 ( Cyt-b5) in the fenvalerate-resistant HDFR strain of cotton bollworm ( Helicoverpa armigera Hübner) and showed that CYP6B7 mRNA was overexpressed and important for resistance to fenvalerate. In the present study, the functional interactions of CYP6B7, NADPH-dependent cytochrome P450 reductase (CPR) and Cyt- b5 were assessed using RNA interference (RNAi) strategies and monitoring for fenvalerate resistance levels. RESULTS: RT-qPCR analyses indicated that the expression levels of CYP6B7, CPR and Cyt-b5 mRNA were decreased drastically in the midgut of fourth-instar larvae of the H. armigera HDFR strain after corresponding double-stranded RNA (dsRNA) injection, compared with that of the control. The knockdown of CYP6B7, CPR and Cyt-b5 transcripts was time course dependent during a 12-48 h period after dsRNA injection. At the earlier time points analysed, significant suppression of CYP6B7 mRNA levels was observed in larvae injected with dsCYP6B7-313 as compared with controls, and further suppression was observed in larvae injected with dsCYP6B7-313, dsCPR-403 and dsCyt-b5. The injection of dsCYP6B7-313 together with dsCPR-403 and dsCyt-b5 increased larval susceptibility of the HDFR strain to fenvalerate. CONCLUSION: The results demonstrated that silencing of CYP6B7 alone or CYP6B7 together with CPR and/or Cyt-b5 increased the susceptibility of H. armigera to fenvalerate, suggesting that CYP6B7, CPR and Cyt-b5 collaboratively participated in enhanced metabolism of fenvalerate and played an important role in the resistance of H. armigera to fenvalerate. Copyright © 2012 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Worldwide, increasing numbers of insects have evolved resistance to a wide range of pesticides, which hampers their control in the field and, therefore, threatens agriculture. Members of the carbox-ylesterase and cytochrome P450 monooxygenase superfamilies are prominent candidates to confer metabolic resistance to pyrethroid insecticides. Both carboxylesterases and P450 enzymes have been shown to be involved in pyrethroid resistance in Australian Helicoverpa armígera, the noctuid species possessing by far the most reported resistance cases worldwide. However, specific enzymes responsible for pyrethroid resistance in field populations of this species have not yet been identified. Here, we show that the resistance toward fenvalerate in an Australian strain of H. armígera is due to a unique P450 enzyme, CYP337B3, which arose from unequal crossing-over between two parental P450 genes, resulting in a chimeric enzyme. CYP337B3 is capable of metabolizing fenvalerate into 4'-hydroxyfenvalerate, which exhibits no toxic effect on susceptible larvae; enzymes from the parental P450 genes showed no detectable fenvalerate metabolism. Furthermore, a polymorphic H. armígera strain could be bred into a susceptible line possessing the parental genes CYP337B1 and CYP337B2 and a resistant line possessing only CYP337B3. The exclusive presence of CYP337B3 in resistant insects of this strain confers a 42-fold resistance to fenvalerate. Thus, in addition to previously documented genetic mechanisms of resistance, recombination can also generate selectively advantageous variants, such as this chimeric P450 enzyme with an altered substrate specificity leading to a potent resistance mechanism. [ABSTRACT FROM AUTHOR]

Exposure to fenvalerate was demonstrated to be toxic to the male reproductive system. Our previous data revealed that intracellular calcium plays an important role in regulating the above toxicity, through actions on both T-type calcium channels and endoplasmic reticulum calcium signals. The present study explored the effects of fenvalerate on the expression of calmodulin in mouse testis and GC-2spd(ts) cells, and its association with fenvalerate-induced male reproductive toxicity. Male mice were subjected to different doses (3.71, 18.56, 37.12, 92.81 mg/kg bw) of fenvalerate or vehicle control for 4 weeks. Expression of calmodulin was determined by real-time polymerase chain reaction (PCR) and Western blot analysis in mouse testis. Similar approaches were utilized in GC-2spd(ts) cells cultured with 5 μM fenvalerate at different time points. In the in vivo study, all mice survived through the entire 4 weeks. Administration of fenvalerate resulted in a dose-dependent reduction in testis weight/body weight, sperm motility, and increased head abnormality rate. By histological staining, mice treated with fenvalerate at higher doses showed dilated seminiferous tubules and disturbed arrangement of spermatogenic cells. Meanwhile, both mRNA and protein expression of calmodulin were significantly increased in the testes of mice exposed to fenvalerate compared to control mice. Moreover, in the in vitro study, 5 μM fenvalerate significantly increased the expression of calmodulin at the mRNA and protein levels in GC-2spd(ts) cells after 8 h of incubation and sustained these levels for at least 24 h. Collectively, these data suggested that enhanced expression of calmodulin correlates with male reproductive damage induced by fenvalerate. [ABSTRACT FROM AUTHOR]

Abstract: Five experimental diets with various combinations of probiotics, namely T1 & T6 (basal feed (BF) without probiotics), T2 & T7 (BF+ Bacillus subtilis + Lactococcus lactis), T3 & T8 (BF+ L. lactis + Saccharomyces cerevisiae), T4 & T9(BF+ B. subtilis + S. cerevisiae) and T5 & T10 (BF+ B. subtilis + L. lactis + S. cerevisiae) were fed to Labeo rohita fingerlings for 30days. Treatment groups T1, T2, T3, T4 and T5 were exposed to Fenvalerate, at a concentration of 1.79μgL−1. The SOD and CAT activity was significantly affected (P <0.01) in fenvalerate treated groups. However, the supplementation of the three-probiotic mixture at equal concentration showed markedly reduced activity. Similarly, RBC, Hb, NBT, total protein and albumin values were reduced significantly (P <0.01) in the fenvalerate exposed fish as compared to the probiotic supplemented fish. Fenvalerate exposure also showed increased serum ALP, ACP and Bilirubin values (P <0.01) in comparison to the non-exposed fish. Histological observations of the gills, kidney and liver showed tissue degeneration after fenvalerate exposure, which however showed marked recovery on the three-probiotic mixture supplementation. Therefore, these results indicate that a mixture of multi-species probiotic supplementation in equal concentration acts beneficially in mitigating the stressful effects of fenvalerate. [Copyright &y& Elsevier]

Pesticides constitute the important group of environmental pollutants since they are potent metabolic inhibitor. Fenvalerate is an synthetic pyrethroid insecticide that has been in use since 1976. It is gradually being recognized that by use of natural herbs and herbal preparations in aquaculture we can deal with pesticidal problems. The present study aimed to evaluate the characterization of ethanolic extract of Aloe vera (Av) by infra red spectroscopy (IR), Scanning Electron Microscopy (SEM) and to investigate its immunomodulatory, antidiabetic and anticholesterol activity in H. fossilis after giving sublethal doses of fenvalerate. As blood is patho-physiological indicator, this study was performed to begin an assessment of the effect of fenvalerate on biochemistry of blood serum. In present study three sublethal doses of fenvalerate [0.25, 0.50 and 0.75 (p.p.m)] were given to test fish, H fossilis for 15 days . After 15 days same fishes were given Av leaf extract [(Av A) 250, (Av B) 500 and (Av C) 1000 (mg/kg of body wt.)] for 30 days to find its protection after intoxication of fenvalerate. Fenvalerate found harmfull in all the three doses and Av was protective against doses of fenvalerate. [ABSTRACT FROM AUTHOR]

The count of red blood cells is quite a stable index and the fish body tries to maintain this count within the limits of certain physiological standards using various physiological mechanisms of compensation. In this investigation, changes in H. fossilis blood cells due to therapeutic effect of Ws for 30 days were investigated after 15 days of exposure to fenvalerate. The present study aimed to evaluate the characterization of fenvalerate and ethanolic extract of Withania somnifera (Ws) by infra red spectroscopy (IR) and X-ray Diffraction (XRD) and as blood is patho-physiological indicator, this study gives an insight into toxic effect of fenvalerate and curable protection of Ws. In present study three sublethal doses of fenvalerate [0.25, 0.50 and 0.75 (p.p.m)] were given to test fish, H fossilis for 15 days. After 15 days same fishes were given Ws root extract [(Ws A) 100, (Ws B) 200 and (Ws C) 300 (mg/kg of body wt.)] for 30 days to find its protection after intoxication of fenvalerate. Fenvalerate found harmfull and Ws was protective against doses of fenvalerate. [ABSTRACT FROM AUTHOR]

Susceptibility of two French strains of stable flies Stomoxys calcitrans (L.) to six insecticides was assayed, using an exposure technique (1-hour contact) with treated filter papers. Three replicates per insecticide, per concentration (10 concentrations per insecticide), per fly strain (ENVT, Cabanac) and fly category (blood-engorged - non-blood-engorged) were performed using a total of 14,400 adult flies in this trial. The LD50 and LD90 are higher for the blood-engorged flies than the non-blood-engorged flies for both strains of S. calcitrans. The LD90 (mg/ m2) of the engorged flies for both strains were respectively: cypermethrin (637.9, 54.9), deltamethrin (264.3, 28.1), fenvalerate (2392.5, 125.1), λ-cyhalothrin (118.2, 41.3), permethrin (353.7, 88.1), and phoxim (194, 226.8). Phoxim, which has not been used in the ENVT for several years, showed the same susceptibility for both strains. The LD90 values obtained for the Cabanac strain (organic farm) were 1 to 4 times lower than the recommended doses of all five pyrethroids. For the ENVT strain (bloodengorged flies), the LD90 was 7.1 and 22.6 times over the recommended doses of both deltamethrin and fenvalerate respectively, which are commonly used insecticides on this site. [ABSTRACT FROM AUTHOR]

A simple spectrophotometric method has been proposed for the determination of widely used pyrethroid pesticides, cypermethrin and fenvalerate. The method is based on the hydrolysis of these pesticides, upon which they release cyanide. The cyanide is reacted with bromine and pyridine to form glutaconic aldehyde, which is then coupled with sulphanilic acid to give an orange red dye in acidic medium having maximum absorbance at 480 nm. Beer's law is obeyed in the ranges of 0.18-1.12 and 0.08-0.64 μg/mL for fenvalerate and cypermethrin, respectively. The proposed method is sensitive and found to be free from interferences of a large number of foreign species and other pesticides. The proposed method could be applied to the determination of fenvalerate and cypermethrin in their formulations and environmental samples. [ABSTRACT FROM AUTHOR]

The effects of chlorpyrifos and fenvalerate on the activity of the cellulase, superoxide dismutase (SOD) and catalase (CAT) of the earthworm ( Eisenia foetida) were studied. Earthworms were exposed to chlorpyrifos and fenvalerate at a final concentration of 10, 20, and 40 mg/kg dry soil, respectively. Tissues from each treatment were collected on days 1, 3, 5, and 7. Compared to the controls, the cellulase activity of E. foetida was inhibited by treatments with chlorpyrifos and fenvalerate. The SOD activity of earthworms exposed to chlorpyrifos was significantly inhibited compared to the control after 1 day of incubation, whereas SOD activity increased on day 3. As exposure to the pesticide progressed, the SOD activity recovered from the stimulative effect and reached the level of the control. The SOD activity of E. foetida in the presence of fenvalerate stress was significantly inhibited at the initial stage of exposure and increased after day 3, whereas the SOD activity continued to decrease in response to increasing exposure to fenvalerate. The CAT activity of E. foetida during pesticide stress first increased and then decreased, after day 5, compared to the controls. Alterations of the enzyme activity under environmental stresses are suggested as indicators of biotic and abiotic stress. [ABSTRACT FROM AUTHOR]

Abstract: Exposure to fenvalerate has been shown to be associated with decreased steroid hormone production by mouse Leydig tumor cells (MLTC-1) in our previous study and the interference with cAMP–PKA pathway cannot explain this inhibitory effect completely. In this study, the same cell line was used to investigate the potential involvement of insulin-like growth factor I (IGF-I) signaling pathway in the downregulation of steroidogenesis by fenvalerate. Results showed that fenvalerate treatment decreased IGF-I secretion significantly which was consistent with the reduced expression of IGF-I mRNA. Then inhibitors of the two downstream pathways of IGF-I were added to the medium. The addition of LY294002 (inhibitor of phosphatidylinositol (PI)-3-kinase) did not alter the declining trend of progesterone production with increasing dosages of fenvalerate treatment while the addition of UO126 (inhibitor of extracellular signal-regulated kinases 1/2 (ERK1/2)) markedly attenuated this trend, which strongly indicated the possible involvement of pathway ERK1/2. In addition, phosphorylation of ERK1/2 was also suppressed by fenvalerate. The results suggest that the mechanism by which fenvalerate decreased steroid hormone production might involve the impairment of IGF-I signal pathway by attenuating the IGF-I production and ERK1/2 phosphorylation. [Copyright &y& Elsevier]

This study assessed the effect of fenvalerate pesticide on the kidney condition Renatosomatic Index (RSI) of a freshwater fish Clarias batrachus. Fenvalerate is a pyrethroid pesticide. The RSI showed decreasing trend when the fishes were exposed to different sub lethal concentrations i. e., 0.02 ppm, 0.04 ppm and 0.08 ppm of fenvalerate for 96 hours. This condition of kidney of the fish can result from incomplete elimination of the fenvalerate from the kidney, thereby affecting the normal metabolism of the fish. Thus, the pyrethroid pesticide such as fenvalerate should be used with caution in agriculture field applications, as it is likely to introduce acute levels of the toxicant into the environment. [ABSTRACT FROM AUTHOR]