Phlorizin alleviates deltamethrin-induced oxidative stress in brine shrimp Artemia

Deltamethrin(DEL),a commonly used pyrethroid pesticide,results in higher reactive oxygen species(ROS)levels in aquatic animals,which consequently unbalance the redox state.Phlorizin(PHL)is a flavonoid and a natural product promising to prevent or reduce pesticide-induced oxidative stress.Artemia is a micro-crustacean widely used in marine hatcheries and an experimental aquatic organism for environmental toxicology research.This research aimed to evaluate the toxicity of DEL on Artemia and the antioxidative effect of PHL against the toxicity.Results show that 0.08-mg/mL PHL exerted its antioxidative effects on hatching percentage of the cysts in 24-h incubation and on body length and survival rate of Artemia in 12-d culture.After 12-d culture,12-,24-,and 36-h DEL exposure showed significant drops in SOD,CAT,and GSH-Px enzyme activities,and significant increases in ROS and malondialdehyde(MDA)levels in Artemia(P<0.05).On the contrary,0.08-mg/mL PHL application improved the enzyme activities and decreased the ROS and MDA levels(P<0.05).Moreover,0.08-mg/mL PHL significantly increased mRNA expression levels of Cu/Zn SOD,CAT,GST,HO-1,NQO1,and Nrf2,and decreased mRNA expression level of Keap1 in the DEL-exposed Artemia(P<0.05).Therefore,DEL is toxic to Artemia,while PHL alleviates DEL-induced oxidative damage by possibly regulating the Nrf2signaling pathway.This study provided a theoretical basis for PHL to reduce pesticide-induced toxicity in aquatic animals.

溴氰菊酯对斑马鱼早期发育阶段的神经毒性研究

溴氰菊酯(deltamethrin,DM)作为Ⅱ型拟除虫菊酯杀虫剂已被广泛使用,高度的亲脂性可以使其轻易通过血脑屏障作用于神经系统,但其对斑马鱼早期神经发育的影响及毒性机制仍不清楚。本研究以斑马鱼(Danio rerio)胚胎为研究对象,分别暴露于0、10、20、50μg·L^(-1)的DM中,对暴露后胚胎的发育状况、运动能力等分析后,进一步利用转基因斑马鱼从神经细胞发育方面评估DM对斑马鱼早期发育阶段的神经毒性。结果显示,从3 hpf开始暴露,在24 hpf,50μg·L^(-1)暴露组自发卷尾运动频率相较于对照组降低了约41.2%(P<0.001);在36 hpf,各暴露组胚胎孵化率均升高,20、50μg·L^(-1)暴露组心率显著升高(P<0.01,P<0.0001),体长显著短于对照组(P<0.01),这些结果显示出DM对胚胎发育的影响于其浓度之间具有明显剂量依赖效应。通过对斑马鱼幼鱼的自发运动、光暗行为和旷场行为的分析,发现暴露后斑马鱼幼鱼在3种情景中运动行为均变得迟缓,表明DM暴露影响斑马鱼运动能力,且对外界环境刺激的响应能力以及主动探索新环境的能力均减弱。进一步通过对神经系统特异性标记的转基因斑马鱼品系的研究发现,DM暴露导致斑马鱼神经干/祖细胞数目显著减少(P<0.01,P<0.001),神经元细胞活性加强,且凋亡细胞数目显著增多(P<0.0001)。结果表明,溴氰菊酯在斑马鱼发育早期的毒性与其影响神经细胞的活性相关。DM通过破坏神经干/祖细胞的数量、过度激活神经元和促进神经细胞凋亡等方面对斑马鱼中枢神经系统产生毒性,进而影响斑马鱼胚胎的运动行为。

溴氰菊酯不同暴露时间对小鼠神经行为的毒性作用研究

目的:探究溴氰菊酯(DM)不同暴露时间对小鼠神经行为的毒性作用。方法:将32只成年雄性C57BL/6J小鼠随机分为30 d(对照组、DM组)和90 d(对照组、DM组)4组,每组8只。DM组经口灌胃4.5 mg/kg(1/20 LD_(50))30 d或90 d,对照组给予等容量玉米油。采用Morris水迷宫(MWM)检测小鼠的学习记忆能力;苏木精—伊红(HE)染色及尼氏染色观察小鼠皮层组织病理学变化;检测皮层组织还原型谷胱甘肽(GSH)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、丙二醛(MDA)的含量。结果:MWM实验结果,30 d的DM组与对照组相比无显著性差异(P<0.05)。90 d的DM组小鼠在目标象限时间、目标象限路程和穿越平台次数均显著少于对照组(P<0.01)。大脑皮层组织GSH的含量,DM 90 d组低于对照组(P<0.05);SOD活力变化,DM 30 d组低于对照组(P<0.01);CAT活力变化,DM 90 d组低于对照组(P<0.01)。结论:低剂量DM不同暴露时间对成年雄性小鼠的学习记忆能力及抗氧化能力具有不良影响,且这种影响随暴露时间的延长而加剧,应重视DM长期低剂量暴露对神经行为的影响。

溴氰菊酯胁迫下家蚕品种辐7解毒酶基因的表达模式

昆虫体内解毒酶的过量表达和活性增强是昆虫对杀虫剂产生抗性的主要原因。辐射诱变家蚕品种辐7对菊酯类农药具有较强的耐受能力,研究溴氰菊酯胁迫下辐7体内解毒酶基因的表达模式,对于解析辐7的农药耐受性机制,培育耐农药污染的家蚕品种具有重要意义。根据不同浓度溴氰菊酯处理后辐7雄蛾的求偶和交配行为观察,最终选择2.5 mg/L溴氰菊酯处理组进行解毒酶基因的表达检测。采用荧光定量PCR检测溴氰菊酯处理后3 h和6 h辐7雄蛾触角解毒酶基因(8个羧酸酯酶基因、2个丝氨酸蛋白酶抑制剂基因、1个糜蛋白酶基因、3个脂肪酶基因、1个细胞色素P450基因和1个谷胱甘肽-S-转移酶基因)的转录水平:7个羧酸酯酶基因的表达先上调再下调,1个羧酸酯酶基因表达先下调再上调;1个细胞色素P450基因、1个丝氨酸蛋白酶抑制剂基因和1个糜蛋白酶基因表达先上调再下调;1个谷胱甘肽-S-转移酶基因、1个丝氨酸蛋白酶抑制剂基因和2个脂肪酶基因表达持续上调;1个脂肪酶基因表达在处理后6 h上调。结果表明,溴氰菊酯处理后诱导辐7雄蛾体内解毒酶基因转录水平上调,从而在一定程度上增强了辐7雄蛾对微量菊酯类农药的耐受性。

刺槐小皱蝽的生活习性及防治试验研究

对刺槐小皱蝽的形态特征、生活史及生活习性进行了详细介绍。在沂水县沂山林场设置3种药剂处理对刺槐小皱蝽进行防治试验,结果表明,敌百虫800倍液喷药、吡虫啉1倍液打孔注药和溴氰菊酯2倍液涂环对其均有较好的防治效果。

海洋生物体中氯氰菊酯、氰戊菊酯、溴氰菊酯残留测定的不确定度分析

根据计量的不确定度判断方法和表示理论,在标准溶液、试样称重、样品定容、标定曲线、仪器检测和试样测量六大领域,对气相色谱法检测的海洋生物体中溴氰菊酯、氰戊菊酯、次溴氰菊酯等有机物的不确定性分析与评价。结果表明,标准曲线所用溶液配制过程对测量结果的不确定度贡献较大,占总比重的28%。样品重复性测定和仪器重复性测量也引入了较多的不确定度,这为准确测量海洋生物体中的氯氰菊酯、氰戊菊酯和溴氰菊酯,减少测量不确定度,提升测量精度提供改进方向。

Sensitive determination of fenpropathrin,cyhalothrin and deltamethrin in environmental water samples using multiwalled carbon nanotubes cartridge prior to HPLC

This paper described a new method for the trace determination of fenpropathrin, cyhalothrin and deltamethrin using multiwalled carbon nanotubes （MWCNTs） cartridge. Important parameters, such as the sample pH, eluent and its volume, sample flow rate and sample volume were investigated in detail. The linear ranges, the detection limits, and precisions （R.S.D.） were in the range of 0.1- 40 μg L^-11, 1.34.3 ng L^-1 and 2.3-2.8%, respectively. The performance of the proposed method was validated with real water samples, and the spiked recoveries were in the range of 91.7-117.8%, respectively. The experimental results demonstrated that the proposed method was an excellent alternative for the routine analysis of such pollutants in environmental samples. 2007 Qing Xiang Zhou. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Oxidative Stress, Biochemical and Histopathological Alterations in the Liver and Kidney of Female Rats Exposed to Low Doses of Deltamethrin (DM):A Molecular Assessment

Objective To evaluate histopathological alterations of the liver and kidney of female rats exposed to low doses of DM and its potential genotoxic activity. Methods Female Wistar rats were randomly assigned to control （3 groups, 6 rats in each） and treatment groups （3 groups, 6 rats in each）. They were subjected to subcutaneous injections of DM （at doses of 0.003, 0.03, and 0.3 mg/kg bw/d） after 30, 45, and 60 d, respectively. Results Significant alterations were recorded in liver parenchyma induced by hepatic vacuolization, fragmented chromatin in nuclei, dilatation of sinusoids and congestions. Lesions within proximal and distal tubules were observed in the kidneys. Tissue congestions and severe alterations within glomeruli were visible. DM as a pyrethroid insecticide induced significant increase （P〈_O.05） of plasma MDA concentrations after 45 d. A significant increase （P_〈0.05） in plasma ALT （after 45 and 60 d） and AST （after 60 d） concentrations was recorded as compared to controls. During the whole experimental period the toxic agent provoked significant DNA damages （P〈0.05）, especially in the dominance of classes 3 and 4 of obtained comet. Conclusion DM even at a very low dose displays harmful effects by disrupting hepatic and renal function and causing DNA damages in puberscent female rats. Low doses of DM are hepatotoxic and nephrotoxic.

Deltamethrin:Promising mosquito control agent against adult stage of Aedes aegypti L.

Objective:To evaluate the effects of deltamethrin against field-collected adults of Aedes aegypti L(Ae.aegypti).Methods:The adults were selected with 0.025%deltamethrin for 40 successive generations.The selected adults were tested with 4%DDT and the emerging larvae were tested with various insecticides to study the cross-resistance spectrum.The knockdown and irritability studies were carried out in adult mosquitoes to investigate their behavioural response to deltamethrin.Results:Forty generations of selection with deltamethrin resulted in only 3.8-fold resistance in the adults of Ae.aegypti.The adults of parent(PS) and selected strains (DAS) exhibited only 0.8-fold cross resistance to 4%DDT.The larvae emerging from the PS and DAS strains did not develop appreciable levels of resistance to various insecticides tested.The knockdown studies revealed KTSO of 14.4 min in PS adults with no signs of recovery even after 24 h. The DAS strains could develop only 1.2 to 1.3-fold knockdown resistance(KDR).The knockdown response of DDT was though 5-6 times slower than deltamethrin but the continued response in deltamethrin-selected adults caused only 1.2-fold KDR.The PS and DAS strains exhibited significant irritability response towards deltamethrin and DDT.The DAS strains showed 5-6 fold increased irritability to deltamethrin as compared to the PS strain.Conclusions:The above results suggest the prolonged effective use of deltamethrin against Ae.aegypti as an adulticide.

Susceptibility to temephos,permethrin and deltamethrin of Aedes aegypti(Diptera:Culicidae) from Muang district,Phitsanulok Province,Thailand

Objective:To investigate the susceptibility to temephos.permethrin and deltamethrin of Aedes aegypti Ae.aegypti),collected from areas with high incidence of dengue hemorrhagic fever cases in Phitsanulok Province.Thailand.Methods:The F1 progenies of Ae.aegypti colony,originated from five sub-districts including Aranyik.Hua Ro,Nai Muang.Ban Krang and Tha Pho,were used in the bioassays following the procedures of World Heath Organization.For larval bioassay.the late third or early fourth-instar lanae were tested with different concentrations of temephos.For adult bioassay.the females were exposed to 0.75%permethrin or 0.05%deltamethrin.LC_(50)value and mortality rate were analyzed to compare the insecticide susceptibility of the larvae and the adults in each area,respectively.Results:The LC_(50) value of temephos for the larvae from Aranyik.Hua Ro.Nai Muang,Ban Krang and Tha Pho sub-districts was 0.017.0.017.0.026.0.061.and 0.113 ppm,respectively.For permethrin,the highest morlalitv rate(86.84%) was found in the mosquitoes from Aranyik but the others were more resistant with the lower morlality rates(16.00-42.67%).The adult morlality rates after exposing to dellaiiielhrin were higher(82.34-98.67%) in all areas.Conclusions:Ae.acgypti larvae were still susceptible to temephos.Conversely,most tested adults tended to resist the penmethrin and deltamethrin.

Effects of deltamethrin on the activation or expression of Nrf2 and on the GCS-HS protein level in primary astrocytes with laser scanning confocal microscope

Objective： To examine the effects of deltamethrin（DM） and tBHQ on the activation of Nrt2 and expression of GCS-HS in primary astrocytes. Methods： Rat primary astrocytes were treated with DM （10μmol/L） and tBHQ （40μmol/L）, for 1 and 6 h respectively. Results： Analysis using immunofluorescent confocal microscopy revealed that tBHQ treatment led to a dramatic increase in the level of Nrt2. The ratio of cytoplasmic Nrt2 protein to nuclear Nrt2 protein was markedly reduced in astrocytes by either tBHQ or DM treatment. The level of Nrf2 was reduced by combined tBHQ with DM treatment for 1 h, but treatment the ratio of cytoplasmic Nrf2 protein to nuclear Nrf2 protein was increased compared with that of the tBHQ only. The expression of GCS-HS in astrocytes was not altered by DM or tBHQ or both in astrocytes. Conclusion： These findings demonstrated for the first time that Nrf2 was activated by pesticides and antioxidants in astrocytes, implicating a tote of Nrf2 in response to pesticide neurotoxicity ingla.

Impact of Indoor Residual-Sprayed Deltamethrin on Different Surfaces in a Malaria Endemic Area in Balai Ringin, Sarawak

Malaria control programme utilizing indoor residual spraying of chemical insecticide is only effective if a high coverage of targeted area is achieved. The effectiveness of the residual spraying, on the other hand, relies on the efficacy and residual activity of the insecticides applied, which to a certain extent are influenced by the nature of the sprayed surfaces. The bioefficacy of indoor residual-sprayed deltamethrin wettable granule (WG) formulation for the control of malaria was compared with the current dose of deltamethrin wettable powder (WP) in malaria endemic areas in Balai Ringin, Sarawak. Doses of 20 mg/m2 WP (control), 20 mg/m2 WG, 30 mg/m2 WG and 40 mg/m2 WG were sprayed separately on different surfaces namely, wooden, rough-bamboo, smooth-bamboo and brick surfaces. Residual activity of WP and WG formulations was tested against lab-bred Anopheles maculatus using WHO standard procedure. Deltamethrin at 30 mg/m2 WG exhibited the highest sustainable level of effectiveness against An. maculatus (An. maculatus mortality was between 95% - 100%) up to week 60 post-spraying when sprayed on smooth- bamboo surface. These results indicated that 30 mg/m2 WG could be an ideal concentration for controlling malaria vector effectively up to 15 months of which long-lasting residual spraying was envisaged. The usual two spraying cycles per year with 20 mg/m2 deltamethrin WP could be replaced with 30 mg/m2 deltamethrin WG since the long residual activity was achieved by employing a single spraying only.

Long Term Perinatal Deltamethrin Exposure Alters Electrophysiological Properties of Embryonic Ventricular Cardiomyocyte

Increased use of pyrethroids and the exposure to pyrethroids for pregnant women and children have raised the concerns over the potential effect of pyrethroids on developmental cardiotoxicity and other abnormalities.The purpose of this study was to investigate whether long tenn peri natal deltamethrin exposure altered embryonic cardiac electrophysiology in mice.Pregnant mice were administered with 0 or 3 mg/kg of deltamethrin by gavage daily from gestational day(gd)10.5 to gd 17.5.Whole cell patch-clamp technique was used in electrophysiological study,and real time RT-PCR was applied to analyze the molecular changes for the electrophysiological properties.Deltamethrin exposure resulted in increased mortality of pregnant mice and decreased viability of embryos.Moreover,deltamethrin slowed the maximum depolarization velocity(Vmax),prolonged the action potential duration(APD)and depolarized the maximuin diastolic potential(MDP)of embryonic cardiomyocytes.Additionally,perinatal deltamethrin exposure decreased the mRNA expression of Na^+channel regulatory subunit Navpl,inward rectifier K^+channel subunit Kir2.1,and delayed rectifier K^+channel subunit MERG while the L-type Ca^2+channel subunit,Cavl.2 expression was increased.On the contraiy,deltamethrin administration did not significantly alter the regulation ofβ-adrenergic or muscarinic receptor on embryonic cardiomyocytes.In conclusion,deltamethrin exposure at perinatal stage significantly alters mRNA expression of embryonic cardiac ion channels and therefore influences embryonic cardiac electrophysiological properties.This highlights the need to understand the persistent effects of pyrethroid exposure on cardiac function during embryonic development due to potential for cardiac arrhythmogenicity.

Studies on the Effects of Deltamethrin on Sodium Net Transport Through the in vivo Amphibian Skin

The action of micromolar concentrations of Deltamethrin on sodium net transport through the in vivo skin of the South American toad Bufo arenarum was studied. The effect of pure ethanolic insecticide solutions and commercial formulations when applied on the mucosal surface was assayed. Deltamethrin provoked a concentration-independent inhibition; the highest inhibition was found at the lowest concentrations. At highest concentrations of the insecticide the J Na was not altered

Application of Gas Chromatography-mass Spectrometry in Analyzing Pharmacokinetics and Distribution of Deltamethrin in Miniature Pig Tissues

Objective To characterize the pharmacokinetics and distribution profiles of deltamethrin in miniature pig tissues by gas chromatography-mass spectrometry （GC-MS）. Methods Pharmacokinetics and distribution of deltamethrin in blood and tissues of 30 miniature pigs were studied by GC-MS after oral administration of deltamethrin （5 mg/kg bw）. Data were processed by 3P97 software. Results The serum deltamethrin level was significantly lower in tissues than in blood of miniature pigs.The AUC0-72 h, Cmax, of deltamethrin were 555.330±316.987 ng h/mL and 17.861±11.129 ng/mL, respectively. The Tmax, of deltamethrin was 6.004±3.131 h.Conclusion The metabolism of deltamethrin in miniature pigs is fit for a one-compartment model with a weighting function of I/C^2. Deltamethrin is rapidly hydrolyzed and accumulated in miniature pig tissues.

First investigation of deltamethrin pyrethroid susceptibility and resistance status of Anopheles labranchiae(Falleroni, 1926), potential malaria vector in Tunisia

Objective: To evaluate the deltamethrin pyrethroid insecticides against Anopheles labranchiae, potential malaria vector in Tunisia.Methods: Six field populations of Anopheles labranchiae mosquitoes were collected from six localities in Northern and Central Tunisia between October and November 2016.Different bioassays were performed to estimate the level of resistance in each collected population. Two synergists were used to estimate the involvement of detoxification enzymes in insecticide resistance.Results: All studied strains were resistant and the RR50 ranged from 12.5 in sample #1 to72.5 in sample #6. Synergist tests using piperonyl butoxide indicated the involvement of monoxygenases enzymes in the recorded resistance. In contrast, the increase of deltamethrin mortality was not significant in presence of S,S,sributyl phosphorothioate(0.8 < SR < 1.2), suggesting no role of esterases(and/or GST) in the resistance phenotype. The correlation recorded between mortality due to DDT and the LC50 of deltamethrin insecticide indicated an insensitive sodium channel affected by Kdr mutation(Spearman rank correlation, r =-0.59, P < 0.01).Conclusions: These results should be considered in the current mosquitoes control programs in Tunisia. The use of pesticides and insecticides by both agricultural and public health departments in Tunisia should be more rational to reduce the development of resistance in populations. Different insecticide applications should be implemented alternately.

Tyrosine Hydroxylase as a Target for Deltamethrin in the Nigrostriatal Dopaminergic Pathway

Objective To study the effects of deltamethrin on tyrosine hydroxylase in nigrostriatum of male rats. Methods Sprague-Dawley rats were daily treated with deltamethrin at 6.25 or 12.5 mg/kg body weight by gavage for 10 days. Then HPLC-fluorescence detection was used to analyze the contents of dopamine （DA）, 3,4-dihydmxyphenylacetic acid （DOPAC） and homoranillic acid （HVA） in substantial nigra and striatum. The activities of tyrosine hydroxylase （TH） were also detected by HPLC-fluorescence detection. TH mRNA or TH protein levels were measured by RT-PCR and immunohistochemistry method. Results The content of DA in stfiatum was significantly decreased by the treatments, suggesting an inhibition of DA synthesis by deltamethrin. The contents of DA metabolites DOPAC and HVA increased, indicating increased dopamine turnover. Furthermore, deltamethrin significantly decreased the activity, as well as the mRNA and protein levels of TH. Conclusions These findings reveal a novel aspect of deltamethfin neurotoxicity and suggest tyrosine hydroxylase as a molecular target of deltamethin on dopamine metabolism in the nigrostriatal pathway.

Distribution and Significance of Nitric Oxide Synthase in Brain Tissues of Rats Exposed to Deltamethrin Insecticide

The distribution of nitric oxide synthase(NOS)in brain tissues of rats exposed to deltamethrininsecticide has been examined by histochemical NADPH-diaphorase staining techniques on frozen sec-tions.After injection of deltamethrin(12.5mg/kg,i.p.),a reproducible sequence of toxic signs ofhyperexcitability were elicited.The observation and image analysis showed that,within brain sec-tions of rats exposed to deltamethrin,the numbers and the total staining areas of the NOS positiveneurons were greatly increased,especially in cerebral cortex,hippocampal formation and paraventric-ular nucleus.In addition,the density of single neuron and the processes were also increased.The re-sults suggested that deltamethrin may induce the NOS expression or activate the NOS activity.TheNOS activation may involve in the chains responsible for the excitatory neurotoxicities induced bydeltamethrin.

Variability of Deltamethrin-Resistant <i>Metarhizium anisopliae</i>Aggressive Strains Group to a Population of the Cossid Moth from <i>Eucalyptus nitens</i>

Random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) was used to examine the genetic variability among Metarhizium anisopliae isolates tested to the cossid moth, Coryphodema tristis. All the isolates tightly clustered into one or the other of two groups that diverged at 12%. Results suggested that certain genotypes of the fungus, that grouped together, were able to infect moth larvae while others did not. A fragment of 760 bp, which presents high homology with a host-adaptation related protein coding gene, distinguished between aggressive and non-aggressive isolates. Neither mycelial growth nor sporulation rate or presence of known virulence genes was correlated with mortality values. Some isolates, including the most aggressive isolate ARSEF2518, were compatible with deltamethrin. Deltamethrin treatment killed all the larvae after seven days whereas fungal and mixed treatments respectively reached the same mortality after 28 and 21 days.

Ameliorative Effects of Spirulina platensis on Deltamethrin-Induced Biochemical Alterations and Oxidative Stress in the African Catfish;Clarias gariepinus

The present study was carried out to determine LC50 of deltamethrin (DM) in the African catfish;Clarias gariepinus, investigate its effects on the biochemical parameters and the antioxidant status of various tissues, and assess the protective role of Spirulina platensis (SP) against DM induced toxicity in C. gariepinus. The fish were distributed into seven groups of 10 fish/each for 30 days as follows: Group 1, control;Group 2, orally administered saline;Group 3, oral SP (150 mg/kg b.w.);Group 4, exposed to 5.19 μg/l DM;Group 5, exposed to 5.19 μg/l DM and orally administered SP (150 mg/kg b.w.);Group 6, exposed to 12.97 μg/l DM;and Group 7, exposed to 12.97 μg/l DM and orally administered SP (150 mg/kg b.w.). Results revealed marked elevation in serum AST, ALT, ALP, creatinine, urea and uric acid. Significant decrease in serum total protein and albumin was recorded. At the same time, the level of malondialdehyde (MDA) was significantly increased in liver, kidney and gills. While, tissue level ofGSHand, SOD,CATandGSH-Px activities were reduced. Treatment with SP improved the biochemical parameters and attenuated the DM induced oxidative damage. Therefore, this study confirmed the protective role of SP as an antioxidant against the toxicity of DM in catfish.