Isolation and identification of bacteria from the invasive pest Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) and evaluation of their biocontrol potential

As an alternative to chemical insecticides, gut bacteria of insects could be used to control insect pests. In this study, bacteria associated with Tuta absoluta, an invasive species that has developed resistance to chemical insecticides, were isolated, and their potential for pest control was investigated. We isolated 13 bacteria from larvae of the pest and identified the isolates on the basis of their morphological, physiological, biochemical, and molecular characteristics as Bacillus thuringiensis (Ta1-8), Staphylococcus petrasii (Ta9), Citrobacter freundii (Ta10), Chishuiella changwenlii (Ta11), Enterococcus casseliflavus (Ta12), and Pseudomonas tremae (Ta13). A laboratory screening test at 109 cfu/ml showed that B. thuringiensis (Bt) isolates caused more than 90% mortality after 3 days. Among the isolates, Bt-Ta1 showed the highest mortality in a short time. The LC50 and LC90 values for Bt-Ta1 were estimated to be 1.2 × 106 and 2 × 109 cfu/ml, respectively. Detailed characterization of Bt-Ta1 revealed that it is one of the serotypes effective on lepidopterans and contains the genes cry1Aa, cry2Aa, and vip3Aa, which encode lepidopteran toxic proteins. Bt-Ta1 isolate has been shown to have the potential to be used in the integrated management of Tuta absoluta. (AU)

Epidemia de escabiosis: los nuevos retos de una enfermedad ancestral / Epidemic Scabies: New Treatment Challenges in an Ancient Disease

La escabiosis es una de las enfermedades transmisibles más prevalentes en el mundo, actualmente en auge en nuestro entorno. Existen diferentes causas que explican la problemática de esta epidemia: una incorrecta aplicación o pauta del tratamiento; la disminución de la sensibilidad o la resistencia al tratamiento tópico y las carencias en el conocimiento del parásito y su transmisibilidad. Por este motivo es necesario un nuevo enfoque en el tratamiento de esta enfermedad que contemple los problemas y la evidencia actual. Si hay una persistencia de la clínica tras un correcto tratamiento es importante corroborar el fracaso terapéutico y estandarizar la actitud. Por último, ante un caso recalcitrante cabría plantear la posibilidad de priorizar el tratamiento oral, aumentar su dosis, realizar tratamientos combinados o plantear su uso fuera de ficha técnica en poblaciones especiales. La aparición de nuevos tratamientos, como el spinosad o, sobre todo, la moxidectina, aportan esperanza en el control de esta enfermedad (AU)

Scabies, which is among the most prevalent diseases worldwide, is becoming more frequent in Spain. The problems of this epidemic can be explained by several factors: improper application or prescription of treatments, resistance or reduced sensitivity to topical treatments, and poor understanding of the parasite and contagion. We require a new evidence-based approach to therapy that takes these problems into consideration. If symptoms persist after proper treatment, it is important to identify the reason for failure and standardize our approach. In refractory cases, the prescriber should prioritize oral medication, indicate a higher dose, combine treatments, or evaluate the use of off-label treatments in certain populations. The availability of new medications —such as spinosad or, especially, moxidectin— offer hope for bringing this disease under control (AU)

[Translated article] Epidemic Scabies: New Treatment Challenges in an Ancient Disease / Epidemia de escabiosis: los nuevos retos de una enfermedad ancestral

Scabies, which is among the most prevalent diseases worldwide, is becoming more frequent in Spain. The problems of this epidemic can be explained by several factors: improper application or prescription of treatments, resistance or reduced sensitivity to topical treatments, and poor understanding of the parasite and contagion. We require a new evidence-based approach to therapy that takes these problems into consideration. If symptoms persist after proper treatment, it is important to identify the reason for failure and standardize our approach. In refractory cases, the prescriber should prioritize oral medication, indicate a higher dose, combine treatments, or evaluate the use of off-label treatments in certain populations. The availability of new medications —such as spinosad or, especially, moxidectin— offer hope for bringing this disease under control (AU)

La escabiosis es una de las enfermedades transmisibles más prevalentes en el mundo, actualmente en auge en nuestro entorno. Existen diferentes causas que explican la problemática de esta epidemia: una incorrecta aplicación o pauta del tratamiento; la disminución de la sensibilidad o la resistencia al tratamiento tópico y las carencias en el conocimiento del parásito y su transmisibilidad. Por este motivo es necesario un nuevo enfoque en el tratamiento de esta enfermedad que contemple los problemas y la evidencia actual. Si hay una persistencia de la clínica tras un correcto tratamiento es importante corroborar el fracaso terapéutico y estandarizar la actitud. Por último, ante un caso recalcitrante cabría plantear la posibilidad de priorizar el tratamiento oral, aumentar su dosis, realizar tratamientos combinados o plantear su uso fuera de ficha técnica en poblaciones especiales. La aparición de nuevos tratamientos, como el spinosad o, sobre todo, la moxidectina, aportan esperanza en el control de esta enfermedad (AU)

Screening of a high-yield strain of avermectin B1a by colony analysis in situ / Selección in situ de una cepa de alto rendimiento de avermectina B1a mediante análisis de colonias

Avermectin, an agricultural antibiotic, is widely used as an agricultural insecticide and an important lead compound of antibiotics. It is manufactured by Streptomyces avermitilis through fermentation. Manufacturers pay special attention to screening for strains with high fermentation capacity based on morphological properties of the colony and by the result of shake flask fermentation. These traditional screening methods are time-consuming and labor-intensive and require specialized equipment. Moreover, evaluation of colony appearance is highly subjective. To improve and accelerate the screening process, we developed a rapid in situ screening method. Forty-four strains isolated naturally from the spores of industrial high-yielding strains were studied. The data show that the colony fermentation titer is highly correlated with the yield from the shake flask fermentation of avermectin, and the Pearson’s R is 0.990. The total titer of avermectins by shake flask fermentation is also highly correlated with the B1a titer (Pearson’s R is 0.994). This result also shows that strains can be quickly screened by analyzing the colony titer. Pigment rings of the colonies that appeared after growing and maturing on the new medium plate were analyzed. The chosen colonies were directly marked and punched and then extracted with methanol. The fermentation ability can be evaluated by measuring the absorbance at 245 nm. This methodology can be applied in both natural breeding and mutation breeding conditions. By continuously breeding from 2008 to 2020, the flask titer of avermectin B1a increased from 4582 ± 483 to 9197 ± 1134 μg/mL.(AU)

Insecticidal features displayed by the beneficial rhizobacterium Pseudomonas chlororaphis PCL1606 / Características insecticidas mostradas por la rhizobacterium beneficiosa Pseudomonas chlororaphis PCL1606

The biocontrol rhizobacterium Pseudomonas chlororaphis is one of the bacterial species of the P. fluorescens group where insecticide fit genes have been found. Fit toxin, supported with other antimicrobial compounds, gives the bacterial the ability to repel and to fight against eukaryotic organisms, such as nematodes and insect larvae, thus protecting the plant host and itself. Pseudomonas chlororaphis PCL1606 is an antagonistic rhizobacterium isolated from avocado roots and show efficient biocontrol against fungal soil-borne disease. The main antimicrobial compound produced by P. chlororaphis PCL606 is 2-hexyl-5-propyl resorcinol (HPR), which plays a crucial role in effective biocontrol against fungal pathogens. Further analysis of the P. chlororaphis PCL1606 genome showed the presence of hydrogen cyanide (HCN), pyrrolnitrin (PRN), and homologous fit genes. To test the insecticidal activity and to determine the bases for such activity, single and double mutants on the biosynthetic genes of these four compounds were tested in a Galleria mellonella larval model using inoculation by injection. The results revealed that Fit toxin and HPR in combination are involved in the insecticide phenotype of P. chlororaphis PCL1606, and additional compounds such as HCN and PRN could be considered supporting compounds.(AU)

Tratamiento de la escabiosis / Treatment of scabies

La escabiosis afecta a más de 200 millones de personas en el mundo, y ocasiona un importante impacto socioeconómico. El mecanismo de contagio es por contacto directo prolongado. El contagio por fómites es infrecuente, aunque puede ser importante en la sarna noruega. La terapia con permetrina tópica al 5% es recomendada como tratamiento de primera línea. Puede indicarse durante el embarazo y la lactancia, y parece ser segura en niños <2 meses. Sin embargo, últimamente se ha reportado una disminución de la efectividad de este fármaco. Otra alternativa en primera línea terapéutica es la ivermectina oral. Se puede administrar durante la lactancia, y estudios recientes sugieren que es segura en niños y lactantes pequeños. Diversas revisiones sistemáticas y metaanálisis han concluido que la ivermectina oral es tan efectiva y segura como la permetrina tópica. La administración terapéutica «en masa» de ivermectina oral es una excelente opción para el manejo de escabiosis en comunidades con alta prevalencia o de brotes en instituciones.

Scabies affects more than 200 million people around the world, and causes a significant socioeconomic impact. Prolonged skin-to-skin contact is the primary mode of transmission. Fomite-mediated transmission is uncommon, although it can be significant in crusted scabies. Topical therapy with permethrin 5% is recommended as first-line treatment. It can be indicated during pregnancy and lactation, and appears to be safe in children <2 months. However, a decrease in the effectiveness of this drug has recently been reported. Another first-line therapeutic alternative is oral ivermectin. It can be administered during lactation, and new evidence suggests that it is safe in children >15kg. Diverse systematic reviews and meta-analysis have concluded that oral ivermectin is as effective and safe as topical permethrin. Mass drug administration of oral ivermectin is an excellent option for the management of scabies in communities with high prevalence, or for scabies outbreaks in institutions.

Respuestas morfofuncionales de larvas de mosquito Aedes aegypti a la Tetrametrina-Real-ZZ® / Aedes aegypti mosquito larvae morphofunctional responses to Tetrametrina-Real-ZZ®

El mayor conocimiento que se tiene sobre la larva del mosquito Aedes aegypti es sobre su eliminación cómo una estrategia para el control de la transmisión de numerosas arbovirosis de las cuales es el principal vector transmisor. Sin embargo, su uso como un posible modelo para ensayos en la toxicología experimental, ha sido poco explotado. En el presente trabajo se muestra un estudio de la toxicidad del insecticida Tetrametrina, presente en un producto comercial de uso doméstico “Real ZZ” ®, sobre larvas de Aedes aegypti, con el objeto de demostrar la utilidad de éstas como un posible modelo alternativo en la toxicología experimental. Se usaron larvas provenientes de un reservorio de agua de lluvia estancada, las cuales fueron tratadas con distintas concentraciones del insecticida, 0, 0.1, 0.2, 0.3, 0.4. y 0.5 %. Se determinó la CL50 y se describió la respuesta funcional y la morfológica, comparando controles y tratados. El ensayo de toxicidad bajo la acción de la CL50, fue valorado en términos de un estudio diagnóstico, haciendo uso de sus herramientas de interpretación como son la Sensibilidad (S) y la Especificidad (E), parámetros representados en una curva ROC, en donde el ABC fue utilizado como como índice de exactitud de la prueba de toxicidad. La respuesta funcional y la morfológica fueron analizadas a través del programa Video Tracker e ImageJ-Fiji respectivamente. Todos los datos fueron procesados en el programa GraphPad Prims. La CL50 fue de 0,33 %, con un índice de exactitud de la prueba de toxicidad del 79,17± 14 %. La velocidad angular del desplazamiento larvario se redujo en un 29,63% y la morfología de la región cefálica y branquial mostro irregularidades topográficas, con relieves entrantes y salientes de diferentes pendientes, con diferencias estadísticamente significativas, p<0.001. Todos los cambios atribuidos probablemente a la acción neurotóxica de la tetrametrina... (AU)

The best knowledge about the larvae of the Aedes aegypti mosquito is about its elimination as a strategy to control the transmission of numerous arborvirus infections, of which it is the main transmitting vector. However, its incorporation as a possible model for tests in experimental toxicology has been little exploited. This work shows a study of the toxicity of the insecticide Tetramethrin, present in a commercial product for domestic use «Real ZZ» ® on Aedes aegypti larvae, in order to demonstrate their usefulness as a possible alternative model in experimental toxicology. Larvae from a stagnant rainwater reservoir were used, which were treated with different concentrations of the insecticide, 0, 0.1, 0.2, 0.3, 0.4. and 0.5%. The LC50 was determined and the functional and morphological response was described, comparing controls and treated. The toxicity test under the action of LC50 was evaluated in terms of a diagnostic study, making use of its interpretation tools such as Sensitivity (S) and Specificity (E), parameters represented in a ROC curve, where ABC was used as an index of accuracy of the toxicity test. The functional and morphological responses were analyzed through the Video Tracker and ImageJ-Fiji programs respectively. All data were processed in the GraphPad Prims program. The LC50 was 0.33%, with an accuracy index of the toxicity test of 79.17 ± 14%. The angular velocity of larval displacement was reduced by 29.63% and the morphology of the cephalic and branchial region showed topographic irregularities, with incoming and outgoing reliefs of different slopes, with statistically significant differences, p <0.001. All changes probably attributed to the neurotoxic action of tetramethrin. It is concluded that Aedes aegypti mosquito larvae, being good emitters of easily measurable and quantifiable physiological responses, could be considered as a biomodel with great potential in toxicological research... (AU)

Essential oil as a new tool for larvicidal Aedes aegypti: A systematic review

Objective: The study aimed to describe the effectiveness of essential oil plants for Aedes aegypti mosquito vector control. Methods: This systematic review selection process following with 2015 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Guideline. The source of the articles from databases international journal were Scopus, Pubmed, Scinapse and Google Scholar. Result: Natural control management with essential oil is the way of alternative for larvicidal mosquito control especially A. aegypti. The essential oil for many plants can use for larvicidal against A. aegypti as Piper batle L., Tinospora rhumpii, Azadiractha indica, Persea americana, Piper aduncum, Leucas aspera, Eucaliptus camaldulensis, Ottonia anisum, Salvia Plebeian, Lantana camara, and Syzygium aromaticum with 100% mortality larvae A. aegypti at 48 h. Conclusions: The vector borne diseases must be used to integrate vector management control with essential oils plants. (AU)

Level of knowledge and insight of educational workforce in Iligan City on Insecticide Treated Screen (ITS) program

OBJECTIVES: This study aims to provide assessment tool on public elementary schools in Iligan City regarding corresponding level of knowledge of the educational workforce on Dengue Fever and Insecticide Treated Screen (ITS) program, perceptions and prevalent anti-dengue practices for which to support Anti-Dengue Advocacy Program. METHODS: The study utilized a descriptive research design. It involves general knowledge as to the causes and mode of transmission of dengue fever. It also determined the level of knowledge of ITS as a program on the following parameters distribution, coordinating programs, composition, level of protection, durability, effectivity, and usage as well as their perception regarding the usefulness, amount of information dissemination, level, prevalent practices benefits and possible barriers on the utilization of Insecticide Treated Screen (ITS) program. RESULTS: This study yields respondents have higher understanding on the concept of dengue, low understanding on Insecticide Treated Screen as a program and average understanding of ITS as a product. Probable barriers have been identified that limits the use of the product, which include ITS being prone to damage by the students. CONCLUSION: This study implicates respondents are fairly knowledgeable of ITS as a product, it does not coincide with their knowledge of ITS as a program. Information dissemination is limited particularly on the subject of ITS being a program

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Isolation and characterization of a lindane degrading bacteria Paracoccus sp. NITDBR1 and evaluation of its plant growth promoting traits

Lindane contamination in different environmental compartments is still posing a serious threat to our environment and effective measures need to be taken for the detoxification of lindane. Soil bacteria isolated from agricultural fields are known to possess certain plant growth promoting traits like the production of phytohormones, production of ammonia, nitrogen fixation and solubilization of phosphorus, etc. In the present study, an indigenous bacterial strain Paracoccus sp. NITDBR1 have been isolated from an agricultural field in Manipur, India which could grow on 100 mg L−1 lindane as the sole source of carbon and could degrade up to 90% of lindane in mineral salt media under liquid culture conditions in 8 days. The strain NITDBR1 was able to form biofilm in lindane media and the addition of substrate like glucose and sucrose enhanced the biofilm formation by 1.3 and 1.17-fold respectively in 3 days. The strain NITDBR1 could produce glycolipid and glycoprotein based biosurfactants. It was also found to possess plant growth promoting traits like nitrogen fixation and indole-3-acetic acid production to assist crop production. The phytotoxicity studies carried out on mustard seeds revealed that the degradation products formed after treatment with NITDBR1 could lower the toxicity of lindane for root elongation by 1.3-fold. Therefore, strain NITDBR1 could be useful for the bioremediation of soil contaminated with lindane with lesser damage to the environment, biofilm forming ability may help the bacteria survive under stressed environmental conditions, and biosurfactant production will help in increasing the bioavailability of contaminants. The plant growth promoting traits can be beneficial for agriculture. With such soil friendly activities coupled with pesticide degradation, this strain can be used for environmental as well as agricultural applications

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Ginger and vitamin C as protective agents against oxidative stress and liver injury induced by methyl parathion

Methyl parathion is one of the highly toxic organophosphorus (OP) compounds. It induces hepatotoxicity, which might be related to generation of reactive oxygen species. This study was carried out to investigate the protective roles of vitamins C and ginger against hepatotoxicity induced by methyl parathion in male albino rats.Sixty male albino rats were randomly divided into 6 groups (ten rats each). Group I was considered as controls. Animals of groups II, III and IV were given methyl parathion (2 mg/kg), ginger (200 mg/kg) and vitamin C (100 mg/kg) respectively. Groups V and VI were given ginger (200 mg/kg) and vitamin C (100 mg/kg) respectively 2 hours before methyl parathion administration. All animals were treated orally, once daily, for four weeks. Blood and liver samples were obtained for biochemical, immunohistochemistry and histopathological examinations.Administration of either ginger or vitamin C along with methyl parathion significantly reduced the alanine aminotransferase (ALT) and malondialdehyde (MDA) levels in rats compared to those only treated with methyl parathion. Treatment with either ginger or vitamin C in combination with methyl parathion resulted in increased level of reduced glutathione compared to the methyl parathion treated group. However, oral ginger significantly increased glutathione-S-transferase levels compared to the control group, and this may outbalance the protective value of ginger over vitamin C to guard against liver injury and oxidative stress. The immunohistochemical and histopathological examinations showed that ginger or vitamin C combination with methyl parathion resulted in less hepatocytes degeneration and milder portal tract infiltration compared to the methyl parathion group.In conclusion, pre-treatment with either ginger or vitamin C appears to alleviate methyl parathion-inducted hepatotoxicity. However, their protective role is still limited and needs further investigation

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Efecto del neonicotinoide - tiametoxam en el desarrollo embrionario del pez cebra (Danio rerio) / Effect of neonicotinoid - thiamethoxam in the zebrafish (Danio rerio) embryonic development

El pez cebra ha surgido como la mejor opción para ensayos toxicológicos, ofrece ventajas marcadas como un modelo de desarrollo de vertebrados y permite comprender las dinámicas de diversas sustancias tóxicas. Actualmente se ha encontrado una creciente preocupación por el uso de plaguicidas neonicotinoides y los posibles efectos ecológicos y ecotoxicológicos sobre los polinizadores y los invertebrados, y los efectos indirectos en ecosistemas acuáticos. El objetivo principal fue evaluar las alteraciones fenotípicas desde huevo hasta el periodo larval del pez cebra (Danio rerio) (6 días aproximadamente) relacionadas con tres dosis (0,48µg/ml, 0,90µg/ml, 1,30µg/ml) de plaguicida Neonicotinoide (tiametoxam). Para esto se usaron cuatro repeticiones, cada repetición con veinte huevos. Se realizó un diseño de bloques al azar evaluando la tasa de mortalidad y una descripción macroscópica de las alteraciones provocadas por este plaguicida, se encontraron alteraciones como: cifosis, lordosis, edema pericárdico, edema del saco vitelino, hipertrofia en las aletas y una ralentización en el desarrollo, la mayor tasa la presentó el tratamiento 3 (1,30µg/ml), demostrando que el neonicotinoide tiametoxam es tóxico y letal para el pez cebra

Zebrafish has emerged as the best choice for toxicological testing, present marked advantages as a model of vertebrate development and allows to understand the dynamics of various toxic substances. There has been growing concern over the use of neonicotinoid pesticides and possible ecological and ecotoxicological effects on pollinators and invertebrates, and indirect effects on aquatic ecosystems. The objective was to evaluate phenotypic alterations from egg to larval period of zebrafish (Danio rerio) (6 days approximately) related to three doses (0,48µg/ml, 0,90µg/ml, 1,30µg/ml) of the pesticide Neonicotinoid (Thiamethoxam), for this, four replicates were used, each repetition with twenty eggs. A randomized block design was performed evaluating the mortality rate and a macroscopic description of the alterations caused by this pesticide, alterations were found such as: kyphosis, lordosis, pericardial edema, yolk sac edema, fins hypertrophy and a slowdown in development, demonstrating a higher mortality rate in the treatment with higher concentration (1,30µg/ml). The neonicotinoid thiamethoxam that proved to be toxic and lethal to the zebrafish

Perspectiva histórica de antimaláricos de origen natural / Historical perspective of antimalarials of natural origin

Hoy, muchas enfermedades son tratadas gracias al descubrimiento de compuestos a partir de las plantas, lo que evidencia que estas juegan un papel significativo en el descubrimiento y desarrollo de nuevos fármacos. Una de las alternativas para el control de la morbi-mortalidad por malaria es la quimioterapia, la cual ha sido posible gracias al descubrimiento de compuestos a partir de las plantas. En la actualidad, cerca de la mitad de los fármacos antimaláricos disponibles son compuestos naturales o están relacionados con ellos. En esta revisión se hace un recuento histórico del origen y desarrollo de los principales antimaláricos como instrumento de hechos arquitectónicos, que mantienen una estrecha relación con los referentes antimaláricos, que sirven de modelos para profundizar en la búsqueda de nuevas sustancias químicas naturales que podrían contribuir al control de una devastadora enfermedad como la malaria, donde se están presentando cepas resistentes de Plasmodium a los principales tratamientos, falla terapéutica, además de un escaso acceso a los medicamentos, entre otros factores; que complican su prevención y tratamiento (AU)

Today, many diseases are treated thanks to the discovery of compounds from plants, which shows that they play a significant role in the discovery and development of new drugs. One of the alternatives for the control of malaria morbidity and mortality is chemotherapy, which has been made possible by the discovery of compounds from plants. At present, about half of the available antimalarials drugs are naturally occurring compounds or are related to them. This review provides a historical account of the origin and development of the main antimalarials as an instrument of architectural facts, which maintains a close relationship with the antimalarials referents, which serve as models to deepen the search for new natural chemical substances that could contribute to the Control of a devastating disease like malaria, where resistant strains of Plasmodium are being presented to the main treatments, therapeutic failure, in addition to poor access to medicines, among other factors; which complicate their prevention and treatment (AU)

Toxicidad de agentes antiparasitarios, antimicrobianos e insecticidas sobre larvas del camarón salino Artemia franciscana (Crustacea: Artemiidae) / Toxicity of antiparasitic, antimicrobial agents and insecticides on larvae of brine shrimp Artemia franciscana (crustacea: artemiidae)

Artemia franciscana "camarón salino", es un crustáceo sensible a un amplio rango de compuestos químicos, de fácil manejo en el laboratorio, y con un cultivo relativamente sencillo y barato. El objetivo del presente trabajo fue evaluar la toxicidad de agentes antiparasitarios, antimicrobianos e insecticidas sobre A. franciscana para establecer la concentración prevista que no causa efectos (PNEC) sobre los organismos marinos y obtener los niveles guía para la protección de la vida acuática. Con los nauplios II de A. franciscana, dentro de las 24 h de eclosión, se procedió a realizar los bioensayos de toxicidad calculando la Concentración letal media (CL50) a 24 h y 48 h de exposición. Se observó la siguiente secuencia de mayor a menor toxicidad a 48 h de exposición para tres agentes antiparasitarios comerciales: Mebendazol >Albendazol >Metronidazol. Con relación al efecto tóxico letal de seis agentes antimicrobianos comerciales se vio la siguiente secuencia de mayor a menor toxicidad a 48 h de exposición: Triclosan >Clotrimazol >Itraconazol >Ketoconazol >Oxitetraciclina >Mimosa. El camarón salino mostró efectos de mortalidad por acción de cinco sustancias con propiedades insecticidas, encontrándose el siguiente orden de mayor a menor mortalidad a 48 h de exposición: Cipermetrina >Rotenona >Carbaryl >Canela >Malation. Las tres sustancias químicas calificadas como muy tóxicas y que presentaron los niveles guía más bajos para la protección de la vida acuática fueron Triclosan (0,72 ug·L-1), Cipermetrina (0,84 ug·L-1) y Clotrimazol (0,97 ug·L-1). Se observó que diez (71,42%) de las sustancias químicas mostraron fuerte actividad citotóxica (AU)

Artemia franciscana "brine shrimp", is sensitive to a wide range of chemical structures, and easy handling in the laboratory and with a relatively simple and inexpensive crustacean culture. The aim of this study was to evaluate the toxicity of parasiticides agent, antimicrobials agent and insecticides on A. franciscana to establish Predicted No-Effect Concentration (PNEC) on marine organisms and obtain guidance levels for the protection of aquatic life. With A. franciscana nauplii II, within 24 h of hatching, we proceeded to perform toxicity bioassays calculating the average lethal concentration (LC50) at 24 h and 48 h of exposure. The following sequence of high to low toxicity to 48 h of exposure to three commercial antiparasitic agents were observed: Mebendazole> Albendazole> Metronidazole. Regarding the lethal toxic effect of six commercial antimicrobial agents about A. franciscana, the following sequence of toxicity at 48 h of exposure was observed: Triclosan> Clotrimazole> Itraconazole> Ketoconazole> oxytetracycline> Mimosa. The brine shrimp mortality showed effects on five substances with insecticidal properties, meeting the following order from highest to lowest mortality at 48 h of exposure Cipermethrin >Rotenone >Carbaryl >Cinnamon >Malathion. The three chemicals were classified as very toxic and presented lower levels guidance for the protection of aquatic life were Triclosan (0,72 ug·L-1), Cipermetrina (0,84 ug·L-1) y Clotrimazol (0,97 ug·L-1). Ten of chemicals (71.42%) showed strong cytotoxic activity (AU)

Mediation of a glutamate antagonist, a NOS inhibitor and antioxidants with - SH groups on striatal dopamine release induced by clothianidin

Is Clothianidin is a neonicotinoid insecticide with selective action on nicotinic acetylcholine receptors. The aim of this study was to determine if the administration of a glutamate antagonist (APV), a NOS inhibitor (L-NAME) or two antioxidants (glutathione, and dithiothreitol,) prevent the increase in the striatal dopamine levels induced by clothianidin, using the microdialysis technique in freely moving and conscious rats. Intrastriatal administration of clothianidin (3.5 mM) produced an increase in striatal dopamine levels of 2462 ± 627%, with respect to basal levels. Coadministration of 0.65 mM APV and 3.5 mM clothianidin generated an increase in extracellular dopamine levels of 1089 ± 243.5%, being this increase 55.7% lower than the generated by clothianidin alone. Coadministration of 0.1 mM L-NAME and 3.5 mM clothianidin generated a significant increase in extracellular dopamine levels of 836.5 ± 150.6%., this increase is 70% lower than the generated by clothianidin alone. Coadministration of 3.5 mM clothianidin in combination with 0.4 mM glutathione induced an increase in striatal dopamine levels of 465.6 ± 126.8% , indicating that the administration of glutathione results in an inhibition of 81% of the effect generated by the infusion of clothianidin alone. Administration of 3.5 mM clothianidin associated with 0.005 mM dithiothreitol induced an increase in extracellular dopamine levels in the striatum of 693.8 ± 117.8% with respect to basal levels, being this increase 72% lower that the generated by clothianidin alone. Our results suggest that the effect of clothianidin on striatal dopamine release can be reduced by the administration of a glutamate antagonist, a NOS inhibitor or antioxidants with –SH groups, which suppose a simple protection mechanism against the damage caused for clothianidin (AU)

La clotianidina es un insecticida neonicotinoide con actividad selectiva sobre los receptores de acetilcolina. El objetivo de este estudio es comprobar si un inhibidor de los receptores glutamatérgicvos (APV), un inhibidor de la óxido nítrico sintetasa (L-NAME) y dos antioxidantes como el glutatión y el dithiotreitol previene la liberación de dopamina inducida por la clotianidina, usando la técnica de microdiálisis en ratas conscientes y en libre movimiento. La administración intraestriatal de clothianidina (3.5 mM) produce un aumento de 2462 ± 627%, de los niveles estriatales de dopamina respecto a los niveles basales. La coadministracion de 0.65 mM de APV y 3.5 mM d clothianidina genera un a aumento de 1089 ± 243.5% de los niveles estriatales de dopamina, siendo este incremento 55.7% más bajo que el generado por la clotianidina sola. La Coadministration de.0,1 mM de L-NAMEy3.5 mM de clotianidina genera un aumento de 836.5 ± 150.6% de los nivelesextracelulares de dopamina, siendo este aumento un 55.7% más bajo que el generado por la clotianidina sola. La coadministracion of 3.5 mM clothianidina en combinación con 0.4 mM de glutatión induce un aumento de 465.6 ± 126.8% de los niveles estriatales de dopamina, indicando que la administración de glutatión provoca una inhibición del 81% del efecto generado por la infusión de clotianidina sola. La administración de 3.5 mM de clothianidinajunto con 0.005 mM de diithiothreitol induce un aumento de 693.8 ± 117.8% en los niveles extracelulares de dopamina en el estriado, siendo este incremento 72% más bajo que el generado por la clotianidina sola. Nuestros resultados sugieren que el efecto de la clotianidina sobre la liberación estriatal de dopamina pueden ser reducidos por la administración de un antagonista glutamatérgico, un ihibibidor de la NOS o por antioxidantes con grupo –SH, lo cualsupone un simple mecanismo de protección contra el daño causadopor la clotianidina (AU)