Toxicity and larvicidal activity on Aedes aegypti of citronella essential oil submitted to enzymatic esterification / Toxicidade e atividade larvicida sobre Aedes aegypti de óleo essencial de citronella submetido à esterificação enzimática

Abstract The essential oil of citronella (Cymbopogon winterianus) has several biological activities, among them the insect repellent action. Some studies showed that cinnamic acid esters can be applied as natural pesticides, insecticides and fungicides. In this context, the objective of the present work was to evaluate the production of esters from citronella essential oil with cinnamic acid via enzymatic esterification. Besides, the essential oil toxicity before and after esterification against Artemia salina and larvicidal action on Aedes aegypti was investigated. Esters were produced using cinnamic acid as the acylating agent and citronella essential oil (3:1) in heptane and 15 wt% NS 88011 enzyme as biocatalysts, at 70 °C and 150 rpm. Conversion rates of citronellyl and geranyl cinnamates were 58.7 and 69.0% for NS 88011, respectively. For the toxicity to Artemia salina LC50 results of 5.29 μg mL-1 were obtained for the essential oil and 4.36 μg mL-1 for the esterified oils obtained with NS 88011. In the insecticidal activity against Aedes aegypti larvae, was obtained LC50 of 111.84 μg mL-1 for the essential oil of citronella and 86.30 μg mL-1 for the esterified oils obtained with the enzyme NS 88011, indicating high toxicity of the esters. The results demonstrated that the evaluated samples present potential of application as bioinsecticide.

Resumo O óleo essencial de citronela (Cymbopogon winterianus) possui diversas atividades biológicas, entre elas a ação repelente a insetos. Alguns estudos mostraram que os ésteres do ácido cinâmico podem ser aplicados como pesticidas naturais, inseticidas e fungicidas. Nesse contexto, o objetivo do presente trabalho foi avaliar a produção de ésteres a partir do óleo essencial de citronela com ácido cinâmico via esterificação enzimática. Além disso, foi investigada a toxicidade do óleo essencial antes e após a esterificação contra Artemia salina e a ação larvicida sobre Aedes aegypti. Os ésteres foram produzidos utilizando ácido cinâmico como agente acilante e óleo essencial de citronela (3: 1) em heptano e 15% em peso da enzima NS 88011 como biocatalisadores, a 70 ° C e 150 rpm. As taxas de conversão de cinamatos de citronelil e geranil foram 58,7 e 69,0% para NS 88011, respectivamente. Para a toxicidade sobre Artemia salina foram obtidos CL50 de 5,29 μg mL-1 para o óleo essencial e 4,36 μg mL-1 para os óleos esterificados com NS 88011. Na atividade inseticida contra larvas de Aedes aegypti, obteve-se CL50 de 111,84 μg mL-1 para o óleo essencial de citronela e 86,30 μg mL-1 para os óleos esterificados com a enzima NS 88011, indicando alta toxicidade dos ésteres. Os resultados demonstraram que as amostras avaliadas apresentam potencial de aplicação como bioinseticida.

Integrative analysis in toxicological assessment of the insecticide Malathion in Allium cepa L. system / Análise integrativa na avaliação toxicológica do inseticida Malation no sistema Allium cepa L

Abstract For many centuries human populations have been suffering and trying to fight with disease-bearing mosquitoes. Emerging and reemerging diseases such as Dengue, Zika, and Chikungunya affect billions of people around the world and recently has been appealing to control with chemical pesticides. Malathion (MT) is one of the main pesticides used against mosquitoes, the vectors of these diseases. This study aimed to assess cytotoxicity and mutagenicity of the malathion for the bioindicator Allium cepa L. using a multivariate and integrative approach. Moreover, an appendix table was compiled with all available literature of insecticides assessed by the Allium cepa system to support our discussion. Exposures during 48h to 0.5 mg mL-1 and 1.0 mg mL-1 MT were compared to the negative control (distilled water) and positive control (MMS solution at 10 mg L-1). The presence of chromosomal aberrations, micronuclei frequency, and mitotic index abnormalities was evaluated. Anaphase bridges were the alterations with higher incidence and presented a significantly elevated rate in the concentration of 0.5 mg mL-1, including when compared to the positive control. The integrative discriminant analysis summarizes that MT in assessed concentrations presented effects like the positive control, corroborating its potential of toxicity to DNA. Therefore, it is concluded that MT in its pure composition and in realistic concentrations used, has genotoxic potential in the biological assessment of A. cepa cells. The multivariate integrative analysis was fundamental to show a whole response of all data, providing a global view of the effect of MT on DNA.

Resumo Por muitos séculos, as populações humanas sofrem e tentam combater os mosquitos transmissores de doenças. Doenças emergentes e reemergentes como Dengue, Zika e Chikungunya afetam bilhões de pessoas em todo o mundo e, recentemente, vem apelando ao controle com pesticidas químicos. O Malation (MT) é um dos principais pesticidas usados ​​contra mosquitos, vetores dessas doenças. O objetivo deste estudo foi avaliar a citotoxicidade e a mutagenicidade do MT para o bioindicador Allium cepa L. usando uma abordagem multivariada e integrativa. Além disso, uma tabela suplementar foi compilada com toda a literatura disponível de inseticidas avaliada pelo sistema Allium cepa para apoiar nossa discussão. Exposições ao MT durante 48h a 0,5 mg mL-1 e 1,0 mg mL-1 foram comparadas a um controle negativo (água destilada) e um controle positivo (10 mg L-1 de MMS). Foram avaliadas a presença de aberrações cromossômicas, frequência de micronúcleos e anormalidades no índice mitótico. As pontes anafásicas foram as alterações com maior incidência e apresentaram uma taxa significativamente elevada na concentração de 0,5 mg mL-1, inclusive quando comparadas ao controle positivo. A análise discriminante integrativa resume que o MT nas concentrações avaliadas apresentou efeitos semelhantes ao controle positivo, corroborando seu potencial de toxicidade para o DNA. Portanto, conclui-se que o MT, em sua composição pura e nas concentrações realistas utilizadas, possui potencial genotóxico na avaliação biológica de células de A. cepa. A análise integrativa multivariada foi fundamental para mostrar uma resposta completa de todos os dados, fornecendo uma visão global do efeito da MT no DNA.

Honey as a bioindicator of environmental organochlorine insecticides contamination / Mel como bioindicador de contaminação ambiental de inseticidas organoclorados

Abstract Honey is a suitable matrix for the evaluation of environmental contaminants including organochlorine insecticides. The present study was conducted to evaluate residues of fifteen organochlorine insecticides in honey samples of unifloral and multifloral origins from Dir, Pakistan. Honey samples (5 g each) were extracted with GC grade organic solvents and then subjected to Rotary Evaporator till dryness. The extracts were then mixed with n-Hexane (5 ml) and purified through Column Chromatography. Purified extracts (1μl each) were processed through Gas Chromatograph coupled with Electron Capture Detector (GC-ECD) for identification and quantification of the insecticides. Of the 15 insecticides tested, 46.7% were detected while 53.3% were not detected in the honey samples. Heptachlor was the most prevalent insecticide with a mean level of 0.0018 mg/kg detected in 80% of the samples followed by β-HCH with a mean level of 0.0016 mg/kg detected in 71.4% of the honey samples. Honey samples from Acacia modesta Wall. were 100% positive for Heptachlor with a mean level of 0.0048 mg/kg followed by β-HCH with a mean level of 0.003 mg/kg and frequency of 83.3%. Minimum levels of the tested insecticides were detected in the unifloral honey from Ziziphus jujuba Mill. Methoxychlor, Endosulfan, Endrin and metabolites of DDT were not detected in the studied honey samples. Some of the tested insecticides are banned in Pakistan but are still detected in honey samples indicating their use in the study area. The detected levels of all insecticides were below the Maximum Residue Levels (MRLs) and safe for consumers. However, the levels detected can cause mortality in insect fauna. The use of banned insecticides is one of the main factors responsible for the declining populations of important insect pollinators including honeybees.

Resumo O mel é uma matriz adequada para a avaliação de contaminantes ambientais, incluindo inseticidas organoclorados. O presente estudo foi conduzido para avaliar resíduos de 15 inseticidas organoclorados em amostras de mel de origem unifloral e multifloral de Dir, Paquistão. Amostras de mel (5 g cada) foram extraídas com solventes orgânicos de grau GC e, em seguida, submetidas ao evaporador rotativo até a secura. Os extratos foram então misturados com n-hexano (5 ml) e purificados por cromatografia em coluna. Os extratos purificados (1μl cada) foram processados através de cromatógrafo gasoso acoplado a detector de captura de elétrons (GC-ECD) para identificação e quantificação dos inseticidas. Dos 15 inseticidas testados, 46,7% foram detectados enquanto 53,3% não foram detectados nas amostras de mel. O heptacloro foi o inseticida mais prevalente com um nível médio de 0,0018 mg / kg detectado em 80% das amostras, seguido por β-HCH com um nível médio de 0,0016 mg / kg detectado em 71,4% das amostras de mel. Amostras de mel da parede de Acacia modesta foram 100% positivos para heptacloro com um nível médio de 0,0048 mg / kg seguido por β-HCH com um nível médio de 0,003 mg / kg e frequência de 83,3%. Níveis mínimos dos inseticidas testados foram detectados no mel unifloral de Ziziphus jujuba da usina. Metoxicloro, Endosulfan, Endrin e metabólitos do DDT não foram detectados nas amostras de mel estudadas. Alguns dos inseticidas testados são proibidos no Paquistão, mas ainda são detectados em amostras de mel, indicando seu uso na área de estudo. Os níveis detectados de todos os inseticidas estavam abaixo dos Níveis Máximos de Resíduos (MRLs) e seguros para os consumidores. No entanto, os níveis detectados podem causar mortalidade na fauna de insetos. O uso de inseticidas proibidos é um dos principais fatores responsáveis pelo declínio das populações de importantes insetos polinizadores, incluindo as abelhas.

Seguridad y satisfacción de fumigadores para el control de enfermedades transmitidas por vectores en Arequipa / Safety and satisfaction of fumigators for the control of vector-borne diseases in Arequipa

Las enfermedades transmitidas por vectores (ETV) van en repunte, la seguridad y satisfacción del equipo que trabaja en el área de fumigación son prioridad, ya que son el personal clave y estratégico para hacer frente a estas enfermedades que son un gran problema de la salud pública a nivel mundial. Como objetivo se propuso deteminar el nivel de seguridad y satisfacción de fumigadores para el control de enfermedades transmitidas por vectores en Arequipa durante el primer semestre del año 2022. La investigación fue descriptiva, experimental de corte transversal con una muestra de 58 fumigadores. Como instrumento de recolección de datos se aplicó una encuesta validada por expertos que consta de tres secciones con diversos ítems para describir la muestra, perfil sociodemográfico, actividad ocupacional, uso de equipos de protección personal, condiciones de salud y satisfacción de empleo. Se utilizó el programa Excel para elaborar la base de datos y el programa EPIDAT 3.0 para frecuencias, porcentajes e IC 95%. Como resultado, 74,14% eran del sexo masculino y 25,86% femenino, 70,69% tenían 41 años o más, 70,69% tenían más de 10 años de ambigüedad, 32,76% tenían unión de hecho, 48,28% tenían estudios secundarios, por otra parte, 94,83% de colaboradores expuestos a Deltametrina <1 hora en dilución y carga, usan mascarillas y filtros, 86,21% usan guantes, bragas y delantales y 84,48% usa gafas, 53,45% sentían sensación de naúseas o mareos, 93,10% estaban satisfechos con el ambiente laboral. Como conclusión, se hace necesario continuar con investigaciones semejantes en diferentes zonas de Perú(AU)

Vector-borne diseases (VTE) are on the rise, the safety and satisfaction of the team that works in the fumigation area are a priority, since they are the key and strategic personnel to deal with these diseases, which are a major health problem public worldwide. The objective was to determine the level of safety and satisfaction of fumigators for the control of vector-borne diseases in Arequipa during the first semester of 2022. The research was descriptive, experimental, cross-sectional with a sample of 58 fumigators. As a data collection instrument, a survey validated by experts was applied, consisting of three sections with various items to describe the sample, sociodemographic profile, occupational activity, use of personal protective equipment, health conditions, and job satisfaction. The Excel program was used to prepare the database and the EPIDAT 3.0 program for frequencies, percentages and 95% CI. As a result, 74.14% were male and 25.86% female, 70.69% were 41 years of age or older, 70.69% had more than 10 years of ambiguity, 32.76% had a common-law union, 48 28% had secondary education, on the other hand, 94.83% of employees exposed to Deltamethrin <1 hour in dilution and load wear masks and filters, 86.21% wear gloves, panties and aprons and 84.48% wear glasses, 53.45% felt nauseated or dizzy, 93.10% were satisfied with the work environment. In conclusion, it is necessary to continue with similar investigations in different areas of Peru(AU)

Using Citronella to Protect Bees (honeybee Apis mellifera L. ) from certain Insecticides and Their Nano Formulations / Uso da citronela para proteger as abelhas (Apis mellifera L. ) de certos inseticidas e suas nanoformulações

Abstract Experiments were performed investigating citronella (Cymbopogon winterianus Jowitt) as a repellent to honeybee Apis mellifera (L.) (Hymenoptera: Apidae) in Egypt, it was conducted in laboratory in the Department of Entomology and Pesticides Science, Faculty of Agriculture, Cairo University, to check long-term survival of honeybee when exposed to different nano insecticides alone or combined with citronella at the same examination box for each. In this study, we used a modeling approach regarding survival data of caged worker bees under chronic exposure to four insecticides (Chloropyrophos, Nano-chloropyrophos Imidacloprid, Nano-Imidacloprid) each of them was supplemented in a box alone and in combination with citronella. Having three replicates and five concentrations (100, 200, 300, 400 and 500 ppm). Laboratory bioassay of these insecticides showed that chloropyrophos and nano chloropyrophos were the most toxic at their high dose (500 ppm) with LT50 of 120.98 and 122.02 followed by 132.14 and 136.5 minutes for Imidacloprid and Nano-Imidacloprid, respectively. No consumption occurred by bees to mixed sugar syrup with insecticides in all treatments when citronella was added. These data highly recommended that adding citronella is very effective when nicotinoid pesticides are used to longevity honeybee life and keep bee safe.

Resumo Foram realizados experimentos para investigar a citronela (Cymbopogon winterianus Jowitt) como repelente de abelhas Apis mellifera (L.) (Hymenoptera: Apidae) no Egito, conduzidos no laboratório do Departamento de Entomologia e Ciência de Pesticidas, da Faculdade de Agricultura, da Universidade do Cairo, e verificar a sobrevivência a longo prazo das abelhas quando expostas a diferentes nanoinseticidas isoladamente ou combinados com citronela na mesma caixa de exame para cada um. Neste estudo, usamos uma abordagem de modelagem em relação aos dados de sobrevivência de abelhas operárias enjauladas sob exposição crônica a quatro inseticidas (clorpirifós, nanoclorpirifós, imidacloprida e nanoimidacloprida), e cada um deles foi suplementado em uma caixa e em combinação com citronela, tendo três repetições e cinco concentrações (100, 200, 300, 400 e 500 ppm). O bioensaio em laboratório desses inseticidas mostrou que clorpirifós e nanoclorpirifós foram os mais tóxicos em altas doses (500 ppm) com LT50 de 120,98 e 122,02, seguidos por 132,14 e 136,5 minutos para imidacloprida e nanoimidacloprida, respectivamente. Não houve consumo pelas abelhas do xarope de açúcar misto com inseticidas em todos os tratamentos quando a citronela foi adicionada. Esses dados recomendam a adição de citronela, sendo muito eficaz quando pesticidas nicotinoides são utilizados para longevidade das abelhas e para mantê-las seguras.

Fumigant toxicity of some essential oils against Red Flour Beetles, Tribolium castaneum (Herbst) and its safety to mammals / Toxidade fumigante de alguns óleos essenciais contra besouros de farinha vermelha, Tribolium castaneum (Herbst) e sua segurança para mamíferos

Abstract Fumigant activities for three essential oils; Garlic oil (Allium sativum L); Chili pepper (Capsicum annuum L.) and Nigella (Nigella sativa L.) were assessed at different concentrations against the adult and 20-days old larval stages of Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) in the laboratory. The accumulative mortality was observed at different exposure periods (3, 5 and 7 days). The residual effect of garlic oil that was the effective oil, on the treated wheat grains was evaluated with respect to histological changes in the liver, kidney, and stomach of rat fed on this treated wheat. The results showed that the mortality rates of treated stages increased with increasing the time of fumigation treatment. Moreover the highest essential oils toxicity at the Median lethal concentration (LC50) values for exposure periods (3, 5 and 7 days) to fumigation were (126, 53, and 47 mg/L air) for adult stage and were (79, 62, and 41 mg/L air) for larval stage, respectively in the case of Garlic oil treatment. While, the lowest essential oils effective was Nigella oil at the Median lethal concentration (LC50) values for exposure periods (3, 5 and 7 days) to fumigation were (3594, 629, and 335 mg/L air) for adult stage and were (1040, 416, and 227 mg/L air) for larval stage, respectively. The toxicity effect of various essential oils against adults and larvae of T. castaneum at the LC50at 7 days fumigation could be arranged in descending order as follows: Garlic oil, Chili pepper oil, and Nigella oil. The histological changes showed that the organs slightly affected at the fumigation for 3 days. It may be concluded that the garlic essential oil is the good effective fumigant to control T. castaneum in the stored products and it recommended that the fumigation period does not exceed 3 days. The garlic essential oil has the potential for applications in IPM programs for stored-grain pests because of its high volatility and fumigant activity and its safety.

Resumo Atividades fumigantes de três óleos essenciais - óleo de alho (Allium sativum L.); pimenta-malagueta (Capsicum annuum L.) e Nigella (Nigella sativa L.) - foram avaliadas em diferentes concentrações contra adultos e larvas de Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) com 20 dias de idade em laboratório. A mortalidade acumulada foi observada em diferentes períodos de exposição (3, 5 e 7 dias). O efeito residual do óleo de alho, ou seja, o óleo eficaz, nos grãos de trigo tratados foi avaliado em relação às alterações histológicas no fígado, rim e estômago de ratos alimentados com esse trigo tratado. Os resultados mostraram que as taxas de mortalidade dos estágios tratados cresceram com o aumento do tempo de exposição ao tratamento de fumigação. A maior toxidade dos óleos essenciais nos valores de Concentração Letal Média (CL50) para os períodos de exposição (3, 5 e 7 dias) à fumigação foi (126, 53 e 47 mg/L ar) para a fase adulta e (79, 62 e 41 mg/L ar) para a fase de larva, respectivamente no caso do tratamento com o óleo de alho, enquanto que o óleo essencial menos eficaze foi o óleo de Nigella, com valores de CL50 para os períodos de exposição (3, 5 e 7 dias) à fumigação (3594, 629 e 335 mg/L ar) para a fase adulta, e (1040, 416 e 227 mg/L ar) para a fase de larva, respectivamente. O efeito da toxidade de vários óleos essenciais contra adultos e larvas de T. castaneum em LC50 aos sete dias de fumigação pôde ser organizado em ordem decrescente, como segue: óleo de alho, óleo de pimenta e óleo de Nigella. As alterações histológicas mostraram que os órgãos foram levemente afetados na fumigação por três dias. Pode-se concluir que o óleo essencial de alho é um bom fumigante efetivo no controle de T. castaneum nos produtos armazenados, e recomendou-se que o período de fumigação não ultrapassasse três dias. O óleo essencial de alho tem potencial para aplicações em programas de Integrated Pests Management (IPM) para pragas de grãos armazenados, devido à sua alta volatilidade, atividade fumigante e respectiva segurança.

Determination of insecticides' lethal concentrations and metabolic enzyme levels in Triatoma dimidiata / Determinación de concentraciones letales y niveles de enzimas metabólicas de insecticidas en Triatoma dimidiata

Abstract: Objective: The feasibility of the use of WHO impregnated paper and biochemical assays to determine lethal concentrations (LC50 and LC99) and insecticide metabolic enzyme levels of Triatoma dimidiata. Materials and methods: LC50 and LC99 were calculated with WHO papers impregnated at different concentrations of malathion, propoxur and deltamethrin; the percentage of insensitive acetylcholinesterase (iAChE); and the levels of esterases, glutathione S-transferases, and monooxygenases in laboratory nymphs of the first stage (5 to 7 days), were undertaken using the WHO biochemical assays. Results: Respectively the LC50 and LC99 µg/cm2 obtained for malathion were 43.83 and 114.38, propoxur 4.71 and 19.29, and deltamethrin 5.80 and 40.46. A 30% of the population had an iAChE, and only a few individuals had high P450 and β-eterase levels. Conclusion: Impregnated papers and biochemical tests developed by WHO for other insects, proved to be feasible methods in monitoring insecticide resistance and metabolic enzymes involved in T. dimidiata.

Resumen: Objetivo: La factibilidad de usar los papeles impregnados y ensayos bioquímicos según la OMS para determinar concentraciones letales (CL50 y CL99) y niveles enzimáticos en la resistencia a insecticidas en Triatoma dimidiata. Material y métodos: Se calcularon la CL50 y CL99 con papeles impregnados según la OMS a diferentes concentraciones de malatión, propoxur y deltametrina; el porcentaje de acetilcolinesterasa insensible (iAChE); y los niveles de esterasas, glutatión S-transferasas, y monooxigenasas en ninfas de laboratorio del estadio I (5-7 días) se determinaron usando los ensayos bioquímicos según la OMS. Resultados: Se obtuvieron las CL50 y CL99 µg / cm2 respectivamente para malatión 43.83 y 114.38, propoxur 4.71 y 19.29, y deltametrina 5.80 y 40.46. Un 30% de las chinches tuvo iAChE, y sólo pocos individuos tuvieron niveles superiores de P450 y β-eterasas. Conclusión: Los papeles impregnados y ensayos bioquímicos que describe la OMS para otros insectos demostraron ser métodos factibles para monitorear la resistencia a insecticidas y las enzimas metabólicas involucradas en T. dimidiata.

Genotoxic Effects of Semi-Synthetic Isodillapiole on Oviposition in Aedes aegypti (Linnaeus, 1762) (Diptera: Culicidae)

Abstract INTRODUCTION: Semi-synthetic dillapiole compounds derived from Piper aduncum essential oil are used as alternative insecticides to control insecticide-resistant Aedes aegypti. Thus, we aimed to evaluate the genotoxic effects of semi-synthetic isodillapiole on the nuclei of neuroblasts (larvae) and oocytes (females) and the mean oviposition rates of the females over four generations (G1, G2, G3, and G4) of Ae. aegypti. METHODS: Larvae were captured in the city of Manaus, Amazonas state, Brazil, and exposed to isodillapiole in bioassays (20, 40, and 60 µg/mL) and a negative control (0.05% DMSO in tap water) for 4 h. The cerebral ganglia were extracted from the larvae and oocytes from the adult females to prepare slides for cytogenetic analysis. Breeding pairs were established and eggs counts were quantified taken after the bioassays. RESULTS: The analysis of 20,000 interphase nuclei of neuroblasts and oocytes indicated significant genotoxicity (micronuclei, budding, polynucleated cells, and other malformations) compared to that of the control. Metaphasic and anaphasic nuclei presented chromosomal breaks; however, no significant variation and damage was observed in the negative control. A significant reduction in mean oviposition rates was also recorded following exposure to isodillapiole over the four generations (G1, G2, G3, and G4). CONCLUSIONS: The toxic and genotoxic effects of isodillapiole on Ae. aegypti were caused by reduced oviposition in the females and nuclear abnormalities over the four generations of the trials. Further studies are required, rather than our in vitro assays, to verify the efficacy of exposure to this compound for controlling Ae. aegypti.

Ototoxicity of boric acid powder in a rat animal model / Ototoxicidade de ácido bórico em pó em um modelo animal de rato

Abstract Introduction: Boric acid, which has antiseptic and acidic properties, is used to treat external and middle ear infections. However, we have not found any literature about the effect of boric acid powder on middle ear mucosa and inner ear. Objective: The purpose of this study is to investigate possible ototoxic effects of boric acid powder on cochlear outer hair cell function and histological changes in middle ear mucosa in a rat animal model. Methods: Twenty healthy, mature Wistar albino rats were used in this study. The rats were divided into two groups, Group A and Group B, each of which consisted of 10 rats. Initially, the animals in each group underwent distortion product otoacoustic emissions testing of their right and left ears. After the first distortion product otoacoustic emissions test, a surgical microscope was used to make a small perforation in both ears of the rats in each group, and a second distortion product otoacoustic emissions test was used to measure both ears in all of the rats. Boric acid powder was applied to the right middle ear of the rats using tympanic membrane perforation, and the distortion product otoacoustic emissions were measured immediately after the boric acid powder application. The histological changes and distortion product otoacoustic emissions were evaluated three days later in Group A and 40 days later in Group B. Results: No significant differences were found at all of the distortion product otoacoustic emissions frequencies. In Group A, mild inflammation of the middle ear mucosa was found on the third day after boric acid powder application. In Group B, boric acid powder caused mild inflammatory changes on the 40th day, which declined over time. Those changes did not lead to significant fibrosis within the mucosa. Conclusion: In rats, boric acid powder causes mild inflammation in middle ear mucosa and it has no ototoxic effects on cochlear outer hair cell function in the inner ear of rats.

Resumo Introdução: O ácido bórico, que tem propriedades antissépticas e ácidas, é usado para tratar infecções de orelha externa e média. No entanto, não encontramos literatura sobre o efeito do ácido bórico em pó sobre a mucosa da orelha interna e da orelha média. Objetivo: Investigar possíveis efeitos ototóxicos do ácido bórico em pó sobre a função das células ciliadas externas cocleares e alterações histológicas na mucosa da orelha média em um modelo animal de rato. Método: Vinte ratos Wistar albinos maduros e saudáveis foram usados neste estudo. Os ratos foram divididos em dois grupos, Grupo A e Grupo B, cada um dos quais com 10 ratos. Inicialmente, os animais de cada grupo foram submetidos a testes de emissões otoacústicas - produto de distorção, nas orelhas direita e esquerda. Após o primeiro teste de emissões otoacústicas - produto de distorção, utilizou-se um microscópio cirúrgico para fazer uma pequena perfuração em ambas as orelhas dos ratos em cada grupo, e um segundo teste de emissões otoacústicas - produto de distorção foi utilizado para medir e avaliar as orelhas em todos os ratos. O ácido bórico em pó foi aplicado na orelha média direita dos ratos utilizando perfuração da membrana timpânica e as emissões otoacústicas - produto de distorção foram medidas imediatamente após a aplicação de ácido bórico em pó. As alterações histológicas e emissões otoacústicas - produto de distorção foram avaliadas três dias depois no Grupo A e 40 dias depois no Grupo B. Resultados: Não foram encontradas diferenças significativas em todas as frequências da emissões otoacústicas - produto de distorção. No Grupo A, foi observada uma ligeira inflamação da mucosa da orelha média no terceiro dia após a aplicação de ácido bórico em pó. No Grupo B, o ácido bórico em pó causou leves alterações inflamatórias após 40 dias, que diminuíram ao longo do tempo. Essas alterações não levaram à fibrose significativa da mucosa. Conclusão: Em ratos, o ácido bórico em pó causa inflamação leve na mucosa da orelha média e não tem efeitos ototóxicos na função das células ciliadas externas da cóclea na orelha interna.

Validación de un método para la determinación del ácido 3-fenoxibenzoico en orina por QuEChERS, microextracción líquido-líquido dispersiva y cromatografía líquida de alta resolución-arreglo de diodos / Validation of a method for the determination of 3-phenoxybenzoic acid in urine using QuEChERS, microextraction liquid-liquid dispersive and high-performance liquid chromatography-diode array

Los piretroides son insecticidas ampliamente usados no sólo en el ámbito agropecuario y doméstico sino también en salud pública. Una vez absorbidos, son rápidamente metabolizados a compuestos polares eliminados por vía renal. Uno de los metabolitos común a un gran número de piretroides es el ácido 3-fenoxibenzoico (3-PBA) el cual es utilizado como marcador de exposición. Se presenta en este trabajo, la validación de una metodología analítica para la determinación del 3-PBA utilizando QuEChERS acoplado a microextracción líquido-líquido dispersiva con tricloroetileno como disolvente extractivo y cromatografía líquida de alta resolución con detector de foto-arreglo de diodos. La validación se realizó con muestras aisladas de orina de voluntarios adultos de ambos sexos sin exposición conocida y orina sintética. El método resultó lineal en el intervalo 9 μg L-1-79 μg L-1; los límites de detección y cuantificación fueron de 3 μg L-1 y 9 μg L-1, respectivamente. No se observaron señales de interferentes a los tiempos de retención del 3-PBA y del ácido 2-fenoxibenzoico (2-PBA), estándar interno, en las muestras de orina blanco. Las señales cromatográficas en las muestras enriquecidas fueron espectralmente homogéneas. Las precisiones intradiarias (RSDr%) (n= 5) para 9 μg L-1 estuvieron comprendidas entre 9,3%-9,9% y para 27 μg L-1 entre 5,9%-10,6%. Las precisiciones interdiarias (RSDint%) (n=15) para los mismos niveles de concentración fueron de 11,8% y 9,1%, respectivamente. El rango de porcentajes de recuperación para 9 μg L-1 fue de 87%-119% y para 27 μg L-1 de 70%-91%. Se evaluó la estabilidad del analito en la muestra y en el extracto. El analito resultó estable a -20 °C durante 7 días en la muestra y durante 1 día en el extracto. Los valores de incertidumbre relativa e incertidumbre expandida fueron evaluados mediante la ecuación de Horwitz, los resultados obtenidos fueron para el nivel 9 μg L-1 de 33% y 65% y para el nivel 27 μg L-1 de 28% y 55%. La aplicabilidad del método validado fue evaluada con muestras reales de personas sin exposición laboral conocida, quienes declararon haber usado insecticidas piretroides. El método resultó sensible y selectivo.

Pyrethroid insecticides are used not only in the agricultural and domestic environment, but also in public health. Once absorbed, they are rapidly metabolized into polar compounds eliminated by the kidneys. One of the metabolites common to many pyrethroids is 3-phenoxybenzoic acid (3-PBA) which are used to evaluate exposure. We present in this paper the validation of an analytical methodology for the determination of 3-PBA using QuEChERS coupled to dispersive liquid-liquid microextraction with trichloroethylene as an extractive solvent and high-performance liquid chromatography with a photodiode array detector. Validation was carried out with isolated samples of urine from adult volunteers of both sexes without exposure and synthetic urine. The method was linear in the interval 9 μg L-1-79 μg L-1; the limit of detection and quantitation were 3 μg L-1 and 9 μg L-1, respectively. Interfering signals were not observed in the blank urine samples and the chromatographic signals in the enriched samples were spectrally homogeneous. The within-run precision (RSDr%) (n = 5) for 9 μg L-1 were between 9.3%-9.9% and for 27 μg L-1 between 5.9%-10.6%. The between-run precision (RSDint%) (n = 15) for the same concentration levels were 11.8% and 9.1%, respectively. The recovery for 9 μg L-1 ranged from 87%-119% and for 27 μg L-1 from 70%-91 %. The stability of the analyte was evaluated in the sample and in the extract. The analyte in the sample was stable at -20 °C for 7 days and in the extract was stable for 1 day. The values of relative uncertainty and expanded uncertainty obtained by the Horwitz equation were 33% and 65% for 9 μg L-1, and 28% and 55% for 27 μg L-1. The applicability of the validated method was evaluated with real samples of people without known occupational exposure, who declared having used pyrethroid insecticides. The method was sensitive and selective.

Toxicity and motor changes in Africanized honey bees (Apis mellifera L) exposed to fipronil and imidacloprid

ABSTRACT This study evaluated the in vitro toxicity and motor activity changes in African-derived adult honey bees (Apis mellifera L.) exposed to lethal or sublethal doses of the insecticides fipronil and imidacloprid. Mortality of bees was assessed to determine the ingestion and contact lethal dose for 24 h using probit analysis. Motor activities in bees exposed to lethal (LD50) and sublethal doses (1/500th of the lethal dose) of both insecticides were evaluated in a behavioral observation box at 1 and 4 h. Ingestion and contact lethal doses of fipronil were 0.2316 ? 0.0626 and 0.0080 ? 0.0021 μg/bee, respectively. Ingestion and contact lethal doses of imidacloprid were 0.1079 ? 0.0375 and 0.0308 ? 0.0218 μg/bee, respectively. Motor function of bees exposed to lethal doses of fipronil and imidacloprid was impaired; exposure to sublethal doses of fipronil but not imidacloprid impaired motor function. The insecticides evaluated in this study were highly toxic to African-derived A. mellifera and caused impaired motor function in these pollinators.

Experimental hut to study the indoor behaviour and effects of insecticide-treated bednets on phlebotomine sand flies (Diptera: Psychodidae)

BACKGROUND Behavioural effects of insecticides on endophagic phlebotomine sand fly vectors of Leishmania are poorly understood mainly because of the lack of an experimental hut (EH) in which to study them. OBJECTIVE To build an EH to evaluate the effects of long-lasting insecticide-treated nets (LLINs) on Lutzomyia longiflocosa. METHODS The study had two phases: (1) Laboratory experiments using tunnel tests to select the traps for the EH; and (2) EH construction and evaluation of the effects of deltamethrin and lambda-cyhalothrin LLINs on L. longiflocosa females inside the EH. FINDINGS Phase 1: The horizontal-slit trap was the best trap. This trap collected the highest percentage of sand flies, and prevented them from escaping. Therefore, this trap was used in the EH. Phase 2: The main effects of LLINs on L. longiflocosa in the EH were: landing inhibition, inhibition from entering the bednet, induced exophily, and high mortality (total and inside exit traps). CONCLUSIONS The EH was effective for evaluating the effects of LLINs on endophagic sand flies. Although both types of LLINs showed high efficacy, the lambda-cyhalothrin-treated LLIN performed better. This is the first report of induced exophily in sand flies.

Assessment of nephrotoxicity and histopathological lesions of albino rats exposure to DD-force and baygon insecticides / Evaluación de la nefrotoxicidad y lesiones histopatológicas tras la exposición de ratas Albino a los insecticidas DD-Force y Baygon

Although studies suggest adverse effects of pesticides, human exposure to insecticides in homes is increasing and reports on their health effects are limited. The study investigated nephrotoxic effects of organo phosphate and carbamate insecticides, DD-Force and Baygon, in albino rats. Forty-five albino rats divided into groups were exposed to DD-Force (dichlorvos) or Baygon (propoxur) indoor insecticidein wooden boxes in separate exposure duration of 1, 2, 3 and 4 hours/day for 14 consecutive days. Serum and kidney tissue obtained after sacrifice were used to determine markers of renal damage and histopathological analysis, respectively. Exposure of rats to the insecticides showed duration-dependent significant increases (p<0.05) in serum levels of urea, uric acid and creatinine compared to control. However, rats exposed to DD-Force insecticide induced significantly higher levels of urea, uric acid and creatinine compared to Baygon (p<0.05). Histopathological lesions were observed in rats exposed to the insecticides, particularly in the exposure duration of 3 or 4 hours/day. These findings suggest that acute exposure to DD-Force and Baygonis nephrotoxic and may induce renal damage in rats.

Aunque los estudios sugieren efectos adversos de los pesticidas, la exposición humana a los insecticidas en los hogares está aumentando y los informes sobre sus efectos sobre la salud son limitados. Este estudio investigó los efectos nefrotóxicos de los insecticidas órgano fosfato y carbamato, DD-Force y Baygon, en ratas albinas. Cuarenta y cinco ratas albinas divididas en grupos fueron expuestas a DD-Force (diclorvos) o Baygon (propoxur) insecticidas de interior en cajas de madera en una duración de exposición separada de 1, 2, 3 y 4 horas / día durante 14 días consecutivos. Muestras séricas y de tejido renal obtenidas después del sacrificio se utilizaron para determinar los marcadores de daño renal y el análisis histopatológico, respectivamente. La exposición de las ratas a los insecticidas mostró aumentos significativos dependientes de la duración (p<0.05) en los niveles séricos de urea, ácido úrico y creatinina en comparación con el control. Sin embargo, las ratas expuestas al insecticida DD-Force indujeron niveles significativamente más altos de urea, ácido úrico y creatinina en comparación con Baygon (p<0.05). Se observaron lesiones histopatológicas en ratas expuestas a los insecticidas, particularmente en la duración de exposición de 3 o 4 horas/día. Estos hallazgos sugieren que la exposición aguda a DD-Force y Baygonis nephrotóxico y puede inducir daño renal en ratas.

A potent larvicidal agent against Aedes aegypti mosquito from cardanol

ABSTRACT Cardanol is a constituent of Cashew Nut Shell Liquid that presents larvicidal activity against Aedes aegypti. The isolation of cardanol is somewhat troublesome, however, in this work we describe an efficient and inexpensive method to obtain it as a pure material. The compound was used as starting material to make chemical transformation leading to saturated cardanol, epoxides and, halohydrins. These derivatives were tested for toxicity against Aedes aegypti larvae. The results showed that iodohydrins are very promising compounds for making commercial products to combat the vector mosquito larvae presenting a LC50 of 0.0023 ppm after 72 h of exposure.

Richness and density of aquatic benthic macroinvertebrates after exposure to fungicides and insecticides in rice paddy fields

ABSTRACT The objective of this study was to verify the richness and density of aquatic benthic macroinvertebrates after exposure to fungicides and insecticides of the rice paddy fields. In the crop seasons of 2012/13 and 2013/14, field experiments were performed, which consisted of single-dose applications of the fungicides trifloxystrobin + tebuconazole and tricyclazole, and the insecticides lambda-cyhalothrin + thiamethoxam and diflubenzuron, in 10 m2 experimental plots, over rice plants in the R3 stage. Control plots with and without rice plants were maintained in order to simulate a natural environment. Soil samples were collected during rice cultivation for assessment of the macroinvertebrate fauna. Chemical-physical parameters assessed in the experiments included temperature, pH and oxygen dissolved in the water and pesticide persistence in the water and in the soil. The application of a single dose of the pesticides and fungicides in the recommended period does not cause significant negative effects over the richness and density of the macroinvertebrates. Tebuconazole, tricyclazole and thiamethoxam showed high persistence in the irrigation water of rice paddy fields. Thus, the doses and number of applications of these products in crops should be carefully handled in order to avoid contamination of the environment.

Toxicity of clove essential oil and its ester eugenyl acetate against Artemia salina / Toxicidade do óleo essencial de cravo e seu éster acetato de eugenila contra Artemia salina

Abstract The production of compounds via enzymatic esterification has great scientific and technological interest due to the several inconveniences related to acid catalysis, mainly by these systems do not fit to the concept of “green chemistry”. Besides, natural products as clove oil present compounds with excellent biological potential. Bioactives compounds are often toxic at high doses. The evaluation of lethality in a less complex animal organism can be used to a monitoring simple and rapid, helping the identification of compounds with potential insecticide activity against larvae of insect vector of diseases. In this sense, the toxicity against Artemia salina of clove essential oil and its derivative eugenyl acetate obtained by enzymatic esterification using Novozym 435 as biocatalyst was evaluated. The conversion of eugenyl acetate synthesis was 95.6%. The results about the evaluation of toxicity against the microcrustacean Artemia salina demonstrated that both oil (LC50= 0.5993 µg.mL–1) and ester (LC50= 0.1178 µg.mL–1) presented high toxic potential, being the eugenyl acetate almost 5 times more toxic than clove essential oil. The results reported here shows the potential of employing clove oil and eugenyl acetate in insecticide formulations.

Resumo A produção de compostos via esterificação enzimática possui grande interesse científico e tecnológico devido às inúmeras inconveniências relacionadas com a catálise ácida, principalmente por estes sitemas não se adequarem ao atual termo “tecnologias limpas”. Além disso, produtos naturais como o óleo de cravo, apresentam compostos com excelentes potenciais biológicos. Compostos bioativos são quase sempre tóxicos em altas doses. A avaliação da letalidade em um organismo animal menos complexo pode ser usada para um monitoramento simples e rápido, servindo também para a identificação de compostos com potencial atividade inseticida contra larvas de insetos vetores de doenças. Neste sentido, foi determinada a toxicidade frente a Artemia salina do óleo essencial de cravo e do seu derivado acetato de eugenila obtido por esterificação enzimática com lipase Novozym 435. A conversão da reação de síntese de acetato de eugenila foi de 95,6%. Os resultados referentes à avaliação da toxicidade frente ao microcrustáceo Artemia salina demonstraram que tanto o óleo (LC50= 0,5993 µg.mL–1) quanto o éster (LC50= 0,1178 µg.mL–1) apresentam elevado potencial toxicológico, sendo que o éster apresenta aproximadamente 5 vezes mais toxicidade em relação ao óleo. Estes resultados demonstram o potencial emprego do óleo de cravo e de acetato de eugenila em formulações de inseticidas.

Efecto letal agudo de los insecticidas en formulación comercial Imidacloprid, Spinosad y Thiocyclam hidrogenoxalato en obreras de Bombus atratus (Hymenoptera: Apidae) / Acute lethal effect of the commercial formulation of the insecticides Imidacloprid, Spinosad y Thiocyclam hidrogenoxalate in Bombus atratus (Hymenoptera: Apidae) workers

Resumen:Los efectos de los insecticidas sobre las abejas han cobrado gran atención a nivel mundial, sin embargo, son pocos los estudios sobre el efecto de estos agroquímicos en abejas Neotropicales. Bombus atratus es una especie neotropical, distribuida ampliamente en los Andes y es considerado un polinizador importante de ecosistemas y agroecosistemas altoandinos. Sin embargo, al igual que muchas especies silvestres, se desconoce el efecto de los insecticidas en B. atratus. Teniendo en cuenta lo anterior, el presente trabajo determinó la dosis letal media aguda (DL50) por exposición tópica y oral de las formulaciones comerciales de los insecticidas con los ingredientes activos Imidacloprid, Spinosad y Thiocyclam hidrogenoxalato, ampliamente utilizados para el control de plagas de cultivos importantes en Colombia. Las pruebas DL50 se realizaron a partir de modificaciones de los lineamientos establecidos por la EPPO y OEDE para estas pruebas en Apis mellifera. Se evaluaron 5 dosis para cada insecticida y exposición. Se evaluaron 25 obreras de tamaño medio en cada dosis por duplicado. La mortalidad se registró a las 24, 48 y 72 horas después del experimento. Los datos fueron analizados con el modelo de regresión Probit. Para el Imidacloprid la DL50 tópica y oral fue de 0.048 µg/abeja y 0.010 µg/abeja respectivamente. Para el Thiocyclam hidrogenoxalato la DL50 tópica y oral fue de 0.244 µg/abeja y de 0.056 µg/abeja respectivamente. Para el Spinosad, la DL50 por exposición oral correspondió a 0.28 µg/abeja. No fue posible establecer la DL50 por exposición tópica. A partir del cálculo del Cociente de Riesgo (HQ) e Índice de Toxicidad Relativa, los tres ingredientes activos son altamente tóxicos. Se analiza y discute el riesgo debido al uso de los productos evaluados a partir de la naturaleza química de los insecticidas.

Abstract:The effect of insecticides on bees has gained great attention, however, there are few studies that explore this issue on Neotropical bees. Bombus atratus is a neotropical species broadly distributed in Colombia and is considered an important pollinator of both Andean ecosystems and agroecosystems. However, as for many wild bees species, the effect of insecticides on B. atratus is unknow. In this study we determined the acute median lethal dose (LD50) of commercial formulations of insecticides Imidacloprid, Spinosad and Thiocyclam hydrogen oxalate, widely used in Colombia to control several pests of important crops. The LD50 was carried out by oral and contact routes, following and modifying the EPPO and OECD guidelines to perform LD50 on A. mellifera. We evaluated five doses for each route and insecticide, in a total of 25 medium-size workers for each dose by duplicate. Mortality was registered at 24, 48 and 72 hours after the experiment; and data were analyzed with the Probit regression model. For Imidacloprid, contacts and oral LD50 were 0.048 µg/bee and 0.010 µg/bee, respectively. For Thiocyclam hydrogen oxalate, topical and oral LD50 were 0.244 µg/bee and 0.056 µg/bee, respectively. For Spinosad, the oral LD50 corresponded to 0.28 µg/bee; it was not possible to establish the LD50 for the contact route. The Hazard Quotient (HQ) and Index of Relative Toxicity indicated that all three active ingredients are highly toxic. We discussed the risk of the insecticides use on B. atratus, considering their chemical nature. Rev. Biol. Trop. 64 (4): 1737-1745. Epub 2016 December 01.

Toxicidade aguda e risco ecotoxicológico do inseticida tiametoxam para alevinos de tilápia-do-nilo / Acute toxicity and ecotoxicological risk of thiamethoxam insecticide in nile tilapia fingerlings

O tiametoxam é um inseticida neonicotinóide usado em diversas culturas e classificado como perigoso para o meio ambiente.O objetivo do presente trabalho foi avaliar a toxicidade aguda do inseticida, por meio da determinação da CL50%, e o risco ecotoxicológico com mensuração da concentração ambiental estimada (CAE) e do quociente de risco (QR). O experimento foi realizado com alevinos de tilápias expostas a 150, 300, 450, 600 e 750mg/L de Actara(R) WG por um período total de 96 horas. O oxigênio dissolvido, o pH e a temperatura foram mensurados diariamente em todos os aquários. Nos grupos experimentais, houve uma variação dos valores de pH e de OD para as diferentes concentrações do inseticida. A CL50% 96h do Actara(R) para alevinos de tilápia foi de 322,08ppm. O quociente de risco (QR) variou de baixo a alto, de acordo com a metodologia usada.(AU)

The neonicotinoid insecticide thiamethoxam is used in different cultures and classified as dangerous for the environment. The aim of this study was to evaluate the acute toxicity of thiamethoxam by determining the lethal concentration (LC50) and ecotoxicological risk through Estimated Environmental Concentration (EEC) and Risk Quotient (RQ) measurement. The assays were done with Tilapia fingerlings exposed to 150, 300, 450, 600 and 750mg / L Actara WG during 96 hours. Dissolved oxygen, pH and temperature were measured daily in all aquariums. Dissolved oxygen and pH varied in the experimental groups. The LC50 Actara(R); 96h was 322.08ppm. The risk quotient (RQ) ranged from low to high according to the methodology used.(AU)

Potential phytoinsecticide of Annona mucosa (Jacq) (Annonaceae) in the control of brown stink bug / Potencial fitoinseticida de Annona mucosa (Jacq) (Annonaceae) no controle do percevejo-marrom

Plant extract have been recognized as important natural source of insecticide. Herein, we assessed the toxicity of leaves-extract and seeds-extract of Annona mucosa (Annonaceae) against brown stink bug, Euschistus heros (F.) (Hemiptera: Pentatomidae), a soybean pest in Neotropical America. For this, bioassays with nymphs and adults were conducted using the concentrations of 5, 10, 20, 40 and 80 mg.mL-1 of leaves and seeds extract of A. mucosa and DMSO (10%), as control. Ten replicates were conducted by treatment, with five nymphs (3rd instar) by replicate (bioassay with nymphs) and one couple of adults (< 24h of old) by replicate (bioassay with adults). The number of nymphs death (mortality) and survival of adults were assessed. For adults the fecundity (number of eggs) and fertility (number of nymphs hatched) of females also were assessed. The nymphs bioassay has promising results in seeds extract, when compared to leaves extract. The mortality of nymphs treated with seeds extract was dependent-concentration, with increased in mortality in concentrations > 5.0mg.mL-1, while nymphs treated with leaves extract do not exhibit difference between treatments. In adults the survival was reduced, when were treated with seed extract of A. mucosa at concentrations higher than 20mg.mL-1, with reduction up to 92 days in contrast to control. A drastic reduction in the fecundity and fertility was observed, which highlight deleterious action of seed extract against reproductive potential of E. heros. This is the first report about toxicity A. mucosa (leaves and seed) on E. heros, and our results suggest that seeds extract of A. mucosa is promising for control of nymphs and adults of brown stink bug.

Extratos de plantas tem sido reconhecidos como um importante recurso natural de inseticidas. Nesta pesquisa avaliou-se a toxicidade do extrato de folhas e de sementes de Annona mucosa (Annonaceae) sobre o percevejo marrom, Euschistus heros (F.) (Hemiptera: Pentatomidae), uma praga-chave na cultura da soja na America Neotropical. Para tanto, bioensaios com ninfas e adultos foram conduzidos usando as concentrações de 5, 10, 20, 40 e 80 mg.mL-1 do extrato de folhas e sementes de A. mucosa e DMSO (10%), como controle. Dez repetições foram conduzidas por tratamento, com cinco ninfas (3º instar) por repetição (bioensaio com ninfas) e um casal de adultos (< 24h de idade) por repetição (bioensaio com adultos). Foram avaliados o número de ninfas mortas (mortalidade) e a sobrevivência dos adultos. Para fêmeas também foi avaliada a fecundidade (número de ovos) e fertilidade (número de ninfas eclodidas). O extrato de semente de A. mucosa apresentou resultados promissores na mortalidade de ninfas de E. heros, quando comparado ao extrato de folhas. A mortalidade de ninfas tratadas com extrato de semente foi dependente da concentração, com aumento da mortalidade em concentrações > 5,0mg.mL-1, enquanto as ninfas tratadas com extrato de folhas não apresentaram diferença entre os tratamentos. A sobrevivência dos adultos foi reduzida, quando estes foram tratados com extrato de semente de A. mucosa em concentrações maiores que 20mg.mL-1, com redução de até 92 dias, em contraste ao controle. Foi observada uma drástica redução na fecundidade e fertilidade, o que destaca a ação deletéria do extrato de sementes sobre o potencial reprodutivo de E. heros. Este é o primeiro registro sobre a toxicidade de A. mucosa (folhas e sementes) sobre E. heros e os resultados sugerem que o extrato de semente de A. mucosa é promissor para o controle de ninfas e adultos do percevejo marrom.

Morphological analysis of the vestibular system of guinea pigs poisoned by organophosphate / Análise morfológica do sistema vestibular de cobaias intoxicadas por organofosforado

ABSTRACT INTRODUCTION: The vestibular system is responsible for body balance. There are substances that damage it, causing dizziness; these are termed vestibulotoxic substances. Agrochemicals have been investigated for ototoxicity because of studies that identified dizziness as a recurrent symptom among rural workers' complaints. OBJECTIVE: To histopathologically evaluate the vestibular system in guinea pigs exposed to an organophosphate, and to identify the drug's effects on this system. METHODS: Experimental clinical study. Eighteen guinea pigs were used; six of them poisoned with the organophosphate chlorpyrifos at doses of 0.5 mg/kg/day and seven of them at 1 mg/kg/day; and a control group of five guinea pigs was exposed to distilled water, all for 10 consecutive days. Later, ciliary tufts of saccule and utricle maculae were counted by scanning electron microscopy. RESULTS: Comparing the groups, a one-way ANOVA test for the variable "saccule" ( p = 0.0569) and a Kruskal-Wallis test for the variable "utricle" ( p = 0.8958) were performed, revealing no difference among groups in both variables. CONCLUSION: The histopathologic analysis of the vestibular system of guinea pigs exposed to an organophosphate showed no difference in the amount of ciliary tufts of saccule and utricle maculae at the doses tested, although the result for the variable "saccule" was considered borderline, showing a trend for significance.

RESUMO INTRODUÇÃO: O sistema vestibular é responsável pelo equilíbrio corporal. Existem substâncias que o danificam, causando tontura; são chamadas vestibulotóxicas. Agrotóxicos tornaram-se objeto de investigação da ototoxicidade a partir de pesquisas que apontaram tontura como sintoma recorrente entre as queixas de trabalhadores rurais. OBJETIVO: Constitui-se em avaliar a histopatologia do sistema vestibular de cobaias expostas a organofosforados, identificando os efeitos nesse sistema. MÉTODO: É um estudo clínico experimental, que utilizou 18 cobaias, sendo seis intoxicadas com organofosforadoclorpirifós na dose de 0,5 mg/kg/dia; sete na dose de 1 mg/kg/dia, e grupo controle com cinco cobaias expostas a água destilada, durante 10 dias consecutivos. Posteriormente realizou-se a contagem dos tufos ciliares nas máculas dos sáculos e utrículos através microscopia eletrônica de varredura. RESULTADOS: Na comparação intergrupos, para a variável sáculo realizou-se o teste ANOVA one-way (p = 0,0569); para a variável utrículo, utilizou-se o teste Kruskal-Wallis (p = 0,8958), revelando não haver diferença entre os grupos em ambas as variáveis. CONCLUSÃO: Análise histopatológica do sistema vestibular de cobaias expostas a organofosforado não demonstrou diferença na quantidade de tufos ciliares nas máculas dos sáculos e utrículos nas doses testadas, apesar do resultado para a variável sáculo ser considerado limítrofe mostrando uma tendência a significância.