Advances in mosquito repellents / 药学实践杂志

Mosquitoes are the biological vectors of many diseases. Mosquito-borne infectious diseases are serious public health problems in tropical areas. With the increasing resistance of mosquitoes to insecticides, it becomes difficult to control mosquito-borne infectious diseases. The application of mosquito repellents can not only control the spread of mosquito-borne infectious diseases to a certain extent, but also reduce the use of insecticides and relieve the environmental pressure. This paper introduces and summarizes the research progresses of new mosquito repellents in recent years to provide reference resource for the further development of mosquito repellents.

Avaliação dos repelentes: efeitos na saúde humana / Evaluation of repellents: effects on human health / Evaluación de repelentes: efectos sobre la salud humana

Este artigo teve como objetivo avaliar os efeitos do uso de repelentes na população brasileira. Para alcançar o objetivo proposto, foram utilizadas as metodologias da revisão de literatura e a pesquisa documental junto à ANVISA referentes aos repelentes registrados e comercializados no Brasil. De acordo com a RDC nº 7 de 2015 da ANVISA, os repelentes são classificados como produtos de Grau 2, compostos por Produtos de Higiene Pessoal, Cosméticos e Perfumes. Nessa categoria, constatou-se a existência de 113 produtos registrados para comercialização no Brasil. Verificou-se que, apesar do aumento do consumo devido às doenças causadas por picada dos mosquitos Aedes aegypti, a maioria dos repelentes comercializados possuem como princípio ativo as substâncias DEET, Icaridina ou IR3535, não resultando em reações tóxicas relevantes para a população, visto que, essas substâncias são de baixa toxicidade ou atóxicas, como é o caso do IR3535. Faz-se necessário considerar que o uso desses produtos deve seguir rigorosamente as orientações dos fabricantes disponíveis nos rótulos das embalagens no que tange à aplicação, reaplicação, frequência e uso específico para crianças, gestantes e lactantes. No que se refere à eficácia, a Icaridina apresenta-se como mais eficaz que o IR3535 quando considerados os fatores tempo de proteção versus concentração do princípio ativo. Entretanto, a Icaridina, em alguns casos, pode apresentar moderada toxicidade, enquanto que, o IR3535 é atóxico. Observa-se ainda, que mesmo diante desse cenário, o DEET é o mais comercializado e amplamente estudado no país.

This article aimed to evaluate the effects of the use of repellents in the Brazilian population. To achieve the proposed objective, the methodologies of literature review and documentary research with ANVISA regarding repellents registered and marketed in Brazil were used. According to ANVISA's RDC No. 7 of 2015, repellents are classified as Grade 2 products, composed of Personal Hygiene Products, Cosmetics and Perfumes. In this category, it was found the existence of 113 products registered for commercialization in Brazil. It was found that, despite the increased consumption due to diseases caused by bites from Aedes aegypti mosquitoes, most repellents marketed have as active ingredients the substances DEET, Icaridin or IR3535, not resulting in toxic reactions relevant to the population, since these substances are of low toxicity or non- toxic, as is the case of IR3535. It is necessary to consider that the use of these products should strictly follow the manufacturers' guidelines available on the packaging labels regarding application, reapplication, frequency and specific use for children, pregnant and lactating women. With regard to efficacy, Icaridin is more effective than IR3535 when considering the factors protection time versus concentration of the active ingredient. However, Icaridin, in some cases, may present moderate toxicity, while IR3535 is non- toxic. It is also observed that, even in this scenario, DEET is the most marketed and widely studied in the country.

artículo tuvo como objetivo evaluar los efectos del uso de repelentes en la población brasileña. Para alcanzar el objetivo propuesto, se utilizaron las metodologías de revisión bibliográfica e investigación documental con ANVISA sobre repelentes registrados y comercializados en Brasil. De acuerdo con el CDR nº 7 de 2015 de ANVISA, los repelentes se clasifican como productos de Grado 2, compuesto por Productos de Higiene Personal, Cosméticos y Perfumes. En esta categoría, se constató la existencia de 113 productos registrados para comercialización en Brasil. Se constató que, a pesar del aumento del consumo debido a las enfermedades causadas por picaduras de mosquitos Aedes aegypti, la mayoría de los repelentes comercializados tienen como principios activos las sustancias DEET, Icaridina o IR3535, no resultando en reacciones tóxicas relevantes para la población, ya que estas sustancias son de baja toxicidad o no tóxicas, como es el caso del IR3535. Es necesario considerar que el uso de estos productos debe seguir estrictamente las directrices de los fabricantes disponibles en las etiquetas de los envases en cuanto a aplicación, reaplicación, frecuencia y uso específico para niños, mujeres embarazadas y lactantes. En cuanto a la eficacia, la Icaridina es más eficaz que el IR3535 si se consideran los factores tiempo de protección frente a concentración del principio activo. Sin embargo, la Icaridina, en algunos casos, puede presentar una toxicidad moderada, mientras que el IR3535 no es tóxico. También se observa que, incluso en este escenario, el DEET es el más comercializado y ampliamente estudiado en el país.

Comparative study of the oil repellent activity of Copaifera officinalis Linnaeus and Copaifera reticulata Ducke front nymphs of Periplaneta americana Linnaeus

Abstract To control urban pests, especially cockroaches of the Periplaneta americana species, various pesticides have been developed that are increasingly potent and effective. However, the unrestrained application of pesticides has had negative consequences, such as the disappearance of some useful insect species and, consequently, the appearance of new pests, both in the countryside and cities. Due to the current scenario, it was necessary to search for new alternatives for the control of these insects. Among the species studied, Copaíba stood out. The oils were analyzed using GC-MS, b-caryophyllene and a-bergamotene being the predominant compounds. Repellency tests were performed with three different concentrations of C. officinalis and C. reticulata, 500 μg/mL, 250 μg/mL and 125 μg/mL, in triplicate. It can be observed that the oil of C. officinalis was more repellent to the nymphs at concentrations of 500 μg/mL and 250 μg/mL, however, when the behavior in nymphs exposed to the concentration of 125 μg/mL was compared, it was noted that C. reticulata oil was more repellent at this concentration. Copaifera has shown promising activity as a repellent against arthropods owing to the complex chemical composition of its oils.

Smoke of Capsicum baccatum L. var. baccatum (Solanaceae) repels nymphs of triatoma infestans (Klug) (Hemiptera: Reduviidae) / Humo de capsicum baccatum L. var. baccatum (Solanaceae) repele las ninfas de Triatoma infestans (Klug) (Hemiptera: Reduviidae)

Control of the Chagas disease vector, Triatoma infestans (Klug) (Hemiptera: Reduviidae) with synthetic pesticides in Bolivia has become increasingly inefficient due to the development of resistance in the insects. In the Chaco region of Bolivia, guaraní populations have approached the problem by fumigating their houses with the smoke of native plants. Through interviews and field work with local guides, the main plant used by the guaraníes was collected and later identified as Capsicum baccatumL. var. baccatum (Solanaceae). In choice bioassays, filter papers exposed to the smoke of the plant repelled nymphs of T. infestans. Activity remained significant after storing the exposed filter papers for 9 days. Chemical analysis of smoke and literature data suggested that capsaicinoids present in the smoke were responsible for the repellent effect. The data presented provide a rationale for the use of C. baccatumvar. baccatumto control the Chagas vector bythe guaraní populations.

El control del vector de la enfermedad de Chagas, Triatoma infestans (Klug) (Hemiptera: Reduviidae) con plaguicidas sintéticos en Bolivia se ha vuelto cada vez más ineficiente debido al desarrollo de resistencias en los insectos. En la región del Chaco de Bolivia, las poblaciones guaraníes han abordado el problema fumigando sus casas con el humo de las plantas nativas. A través de entrevistas y trabajo de campo con guías locales, se recogió la principal planta utilizada por los guaraníes y posteriormente se identificó como Capsicum baccatumL. var. baccatum (Solanaceae). En bioensayos selectos, los papeles de filtro expuestos al humo de la planta repelieron a las ninfas de T. infestans. La actividad siguió siendo significativa después de almacenar los papeles de filtro expuestos durante 9 días. El análisis químico del humo y los datos de la literatura sugieren que los capsaicinoides presentes en el humo eran responsables del efecto repelente. Los datos presentados proporcionan una justificación para el uso de C. baccatum var. baccatum para el control del vector Chagas por las poblaciones guaraníes.

Responses of green lacewings to semiochemicals: species- and sex-specificity (Neuroptera: Chrysopidae)

ABSTRACT Green lacewings (Chrysopidae) are important predators in agroecosystems. Frequently there are studies which treat these beneficial insects at family level as a whole. This approach, despite its practical advantages, may, however, include many species with markedly different life history traits. As green lacewings are also rather diverse in their chemical ecology, treating several different species within one unit may lead to confusion and confounding effects of natural phenomena in research. Besides interspecific differences, sex-specificity is another important factor to consider in respect of insect chemical ecology. This is especially important for green lacewings, in particular the attraction of females, since oviposition is crucial in their application as biological control agents. The aim of our paper is to provide a brief insight into the diversity of the chemical ecology of green lacewings with a special emphasis on the species- and sex-specific differences in their responses to semiochemicals.

The repellent effect of tea tree oil emulsion on leeches / 药学学报

Leech bites usually lead to more bleeding, and dermal tissue is damaged to form lifelong scars. If leeches enter the body cavity, it will be more dangerous. Therefore, there is an urgent need to develop effective repellents. In this study, oil in water (O/W) emulsion of tea tree oil was prepared with tea tree oil as the main ingredient, and konjac glucomannan (KGM), ethyl cellulose (EC) as the main excipients. The filter-paper ring method and repellent test in water were used to evaluate the repellent effects on leeches. The animal experiments were approved by the Ethics Committee of Academy of Military Medical Sciences and were conducted in accordance with relevant guidelines and regulations. The activities of acetylcholinesterase (AchE), glutathione S-transferase (GST) and carboxylesterase (CarE) in vivo were measured to clarify the repellent mechanisms. The results showed that a uniform and stable tea tree oil emulsion was successfully prepared, which has excellent hydrophilicity and can effectively repel leeches. The tea tree oil emulsion has a good repellent effect on leeches, which can avoid the volatilization of tea tree oil and prolong the effective repelling time. The novel formulation of tea tree oil provides a new idea for repelling effects with long time and high efficiency based on similar essential oil.

A new method for synthesis of N,N-diethyl-m-methylbenzamide

RESUMEN Introducción: La N,N-dietil-m-metilbenzamida o N,N-dietil-m-toluamida (DEET), es muy conocida como repelente de insectos. Además, se utiliza para mejorar la administración dérmica y transdérmica de muchos fármacos. Objetivos: Presentar un procedimiento factible para sintetizar DEET a partir de ácido m-toluico y dietilamina. Métodos: El ácido m-toluico fue activado con 1,1'-carbonil-diimidazol, para obtener el producto intermedio 1- (m-toluoil) imidazol que continúa reaccionando con dietilamina, para producir DEET. De este modo, se mejoran los factores que afectan la síntesis de N, N-dietil-m-toluamida. Resultados: Se obtuvo DEET mediante un procedimiento óptimo. Los subproductos de la reacción son solubles en agua; se eliminan fácilmente mediante el método de extracción líquido-líquido con agua y diclorometano. La mayor parte del DEET obtenido tiene gran pureza. Los rendimientos fueron del 94 al 95 %. Conclusiones: Se ha proporcionado una ruta mejorada para una síntesis simple y eficaz de DEET a partir de ácido m-toluico y dietilamina en presencia de 1,1'-carbonil-diimidazol. El procedimiento de síntesis se realizó en un solo reactor y el aislamiento de DEET se logró mediante extracción líquido-líquido. El tiempo total de procedimiento se redujo significativamente. Este método de síntesis es fácilmente escalable y factible industrialmente.

ABSTRACT Introduction: N, N-diethyl-m-methylbenzamide or N, N-diethyl-m-toluamide (DEET), is well known as an insect repellent. In addition, it is used to improve the dermal and transdermal delivery of many drugs. Objectives: To present a feasible procedure to synthesize DEET from m-toluic acid and diethylamine. Methods: The m-toluic acid was activated with 1,1'-carbonyl-diimidazole, to obtain the intermediate product 1- (m-toluoyl) imidazole that continues to react with diethylamine, to produce DEET. In this way, the factors affecting the synthesis of N, N-diethyl-m-toluamide are improved. Results: DEET was obtained through an optimal procedure. The by-products of the reaction are soluble in water; they are easily removed by the liquid-liquid extraction method with water and dichloromethane. Most of the DEET obtained has high purity. The yields were 94 to 95 %. Conclusions: An improved route has been provided for a simple and efficient synthesis of DEET from m-toluic acid and diethylamine in the presence of 1,1'-carbonyl-diimidazole. The synthesis procedure was carried out in one-pot, and the isolation of DEET was achieved by liquid-liquid extraction. The total procedure time was significantly reduced. This synthesis method is easily scalable and industrially feasible.

Antioxidant and biological activities of essential oil from Colombian Swinglea glutinosa(Blanco) Merr fruit

The objectives of this work were the study of the volatile chemical composition of essential oils (EO’s) from Swinglea glutinosa, as well as to evaluate their antioxidant, repellent and fumigant properties. The EO was obtained by hydrodistillation from the peel of the fruit, gathered in the city of Cartagena, Bolívar (Colombia). The volatile composition was analyzed by gas chromatography coupled to mass spectrometry (GC-MS). The major compounds found in S. glutinosaweregermacrene D (4.8%), limonene (5.2%),-terpineol (6.5%), -pinene (8.5%), nerolidyl acetate (9.8%), and trans-nerolidol (34.6%). S. glutinosashowed antioxidant potential (85.8%) (IC50=142.49 μg mL-1). The EO deployedrepellent activity against the Tribolium castaneumweevil at a concentration of 15.73 nL cm-1at 2 hours of exposure (72%), while the result for the commercial repellent was 50% at the same concentration. EO from S. glutinosadisplayed the best fumigant activity withLC50of 153.4 μg mL-1air. The essential oil from S. glutinosacan be considerated as a natural source of biocides and antioxidants.

Mechanical strength and inhibition of plaque biofilm activity of a novel antibacterial Hawley retainer / 口腔疾病防治

Objectives @#The purposes of this study were to evaluate the long-term mechanical property, bacteria-killing ability, protein resistance and cytotoxicity of a novel antibacterial methyl methacrylate (MMA) resin. @*Methods @#The 2-methacryloyloxyethyl phosphorylcholine (MPC) has been added into the MMA used for making Hawley orthodontic retener according to the mass percentage 0% (control group), 1.5%, 2.25%, 3%, 4.5% and 6%. Specimens from the control group and MPC group were water-aged for 1 d, 90 d and 180 d, and then the universal material testing machine was used to investigate the long-term mechanical properties of the modified MMA specimens in the oral environment. The biofilm metabolic activity, colony-forming unit (CFU) and live/dead staining assay of the biofilms in the control group and MPC group in the oral environment were tested using the dental plaque biofilm model. The micro-bicinchoninic acid (BCA) method was used to determine the amount of protein adsorbed on the specimens. The MTT method was used to evaluate the cytotoxicity of the control group and MPC group.@*Results @#In the simulated oral environment, the addition of 0% to 3% MPC had no significant effect on the mechanical properties of the MMA specimen (P > 0.05). The control group and the modified MMA specimens with 3%MPC were statistically significant in time and the interaction effects between the two groups (P < 0.05). With increasing intervention time, the mechanical strength of both groups decreased, and the effect of time varied with grouping. The protein adsorption on the surface of the modified MMA material after adding 3% MPC decreased by approximately 80%, the metabolic activity of the biofilm decreased by approximately 50%, and biofilm CFU counts decreased by approximately 70% (P < 0.05) compared with the control. There was no statistically significant difference in time or interaction effects between the two groups. The amount of live green bacteria in the 3% MPC group decreased significantly after 1, 90, and 180 d of water aging. There was no significant difference in cytotoxicity between the control group and the MPC group (P > 0.05). @*Conclusions @#The addition of MPC into the MMA resin did not compromise the mechanical properties of the resin and exhibited long-lasting antibacterial and protein-repellent effects.

Nanoemulsified Mentha piperita and Eucalyptus globulus oils exhibit enhanced repellent activities against Anopheles stephensi

Objective: To formulate nanoemulsion from essential oils of Mentha (M.) piperita L. and Eucalyptus (E.) globulus L. and to compare their repellant activity with normal essential oils and N,N-diethyl-m toluamide (DEET) as a standard chemical compound. Methods: In this study, protection time of essential oils and DEET was evaluated on four human subjects using test cage, and their values were determined against Anopheles stephensi. Furthermore, ED

Nanoemulsified Mentha piperita and Eucalyptus globulus oils exhibit enhanced repellent activities against Anopheles stephensi

Objective: To formulate nanoemulsion from essential oils of Mentha (M.) piperita L. and Eucalyptus (E.) globulus L. and to compare their repellant activity with normal essential oils and N,N-diethyl-m toluamide (DEET) as a standard chemical compound. Methods: In this study, protection time of essential oils and DEET was evaluated on four human subjects using test cage, and their values were determined against Anopheles stephensi. Furthermore, ED50 values for the above essential oils were determined using the ASTM E951-94 method. The compositions of essential oils were determined using GC-MS, and droplet size and zeta potential of the nanoemulsion were measured with dynamic light scattering. Results: The results (expressed as mean±SD) showed that protection time of M. piperita 50%, M. piperita Nano 50%, E. globulus 50%, E. globulus Nano 50%, and DEET 25% was (2.89±0.45) h, (4.17±0.28) h, (0.96±0.27) h, (5.51±0.02) h, and (6.10±0.47) h, respectively. ED50 values were 29.10 (95% CI: 23.36-36.06) μg/cm2 for Mentha, 19.39 (15.35-23.99) μg/cm2 for Mentha Nano, 36.10 (28.70-48.01) μg/cm2 for Eucalyptus, 18.50 (14.65-23.23) μg/cm2 for Eucalyptus Nano, and 3.62 (2.68-4.55) μg/cm2 for DEET, respectively. E. globulus Nano and M. piperita Nano provided significantly longer protection than normal essential oils E. globulus and M. piperita (P<0.01). Conclusions: The preparation of nanoemulsion from the essential oils of M. piperita and E. globulus, significantly increases the protection time and reduces ED50 values of these essential oils, hence, M. piperita Nano and E. globulus Nano can be good alternatives to DEET and other chemical compounds.

Chemical Composition and Synergistic Repellent Activity of Jasminum officinale and Anthemis nobilis Essential Oils Against Aedes aegypti Mosquitoes

Abstract@#Introduction: Mosquitoes are important vectors responsible for transmission of many pathogens that cause major human morbidity and mortality. Natural repellents such as essential oils may provide a means of protection from mosquito bites that are safe and more pleasant to use. Methods: In this study, essential oils from the flowers of Jasminum officinale and Anthemis nobilis were characterised by gas chromatography-mass spectrometry and were further tested for their repellent efficacy, individually and in combinations, against Aedes aegypti using a rat model. Results: Forty-two compounds accounting for 77.50% of J. officinale essential oil and fifty-one compounds representing 87.96% of A. nobilis essential oil were identified. Oxygenated monoterpenes and diterpenes constituted 31.14% and 21.20% of J. officinale essential oil, respectively. For A. nobilis essential oil, oxygenated monoterpenes accounted for 84.79% of the compounds identified. The essential oils of J. officinale and A. nobilis at 20% concentration provided repellency of 68.45% and 73.15%, respectively, against Ae. aegypti for 120 min. The mixture of essential oils in a 1:1 ratio (JC1) exhibited 88.20% repellency for 120 min, which was significantly higher than the repellency of 20% concentration of the individual oils. Conclusion: The synergistic interactions among the varied constituents of J. officinale and A. nobilis essential oils enhanced the mosquito repellent activity

Fixatives Increase the Efficacy of Gel Formulations containing Piper aduncum Linnaeus (Piperales: Piperaceae) Essential Oil as Repellent / Jurnal Sains Kesihatan Malaysia

@#Piper aduncum essential oil exhibit repellency activity and has a potential to be use as an alternative for synthetic repellent such as N,N-diethyl-3- methylbenzamide, (DEET). However, the volatility properties of the essential oil decrease their persistence as a topical repellent. Study has shown that formulation of the essential oil with some fixatives may increase their effectiveness. Therefore, this study was conduct to evaluate the effectiveness of gel formulation containing P. aduncum essential oil with two fixative; vanillin and paraffin oil. Gel formulations containing P. aduncum essential oil with 5% and 10% vanillin and 6% paraffin oil was prepared and tested against Aedes aegypti in laboratory using Standards and Industrial Research Institute of Malaysia (SIRIM) bioassay method. After 240 minute post-application, formulation containing 5% and 10% vanillin was able to provide >70% repellency percentage against mosquito while formulation containing 6% paraffin oil gives <30% repellency percentage. As conclusion, P. aduncum based repellent gel containing 5% and 10% vanillin was able to prolong the effect of P. aduncum essential oil as repellent against dengue vector in laboratory.

Potential of natural repellents methylanthranilate and anthraquinone applied on maize seeds and seedlings against house sparrow (Passer domesticus) in captivity / Potencial de repelentes naturais, metilantranilato e antraquinona aplicados em sementes de milho e mudas contra o pardal (Passer domesticus) em cativeiro

Abstract Various bird pests caused severe economic losses to valuable crops and fruit orchards all over the world. Among the birds, house sparrow is also considered to cause heavy plunder, not only to seeds of crops but also seedlings especially in organic farming. In present study two bird repellents, methylanthranilate and anthraquinone tested against house sparrows on maize seeds and seedlings in aviary conditions. Trial group in aviary-I, the treated maize seeds and seedlings with different doses of both bird repellents, control group in aviary-II, untreated seeds and seedlings were provided for three hours in the early morning. In each aviary, two closed circuit cameras were also installed to monitor the behavioral responses against different concentrations of both chemical repellents. Statistical analysis showed that there existed highly significant (P<0.01) variations among the trial and control groups for seeds and seedlings. By comparing both repellents, significant (P<0.05) differences were detected and anthraquinone showed better efficacy when compared to methylanthranilate, but in maize seedlings both repellents equal repellent properties. Non-significant (P>0.05) differences were observed in different grading of both natural chemical repellents for maize seeds while significant (P<0.05) variations were noticed for maize seedlings when provided to sparrows. By videotaped behavior sparrows presented manifest head juddering and feather upsetting activities by consumption of treated seeds and seedlings with higher concentrations of both natural bird repellents.

Resumo Várias pragas de aves causaram graves perdas econômicas para cultivos valiosos e pomares de frutas em todo o mundo. Entre os pássaros, o pardal da casa também é considerado um grande saqueo, não só para as sementes das culturas, mas também para as mudas, especialmente na agricultura orgânica. No presente estudo, dois repelentes de aves, metilantranilato e antraquinona testados contra pardais de casa em sementes de milho e mudas em condições de aviário. O grupo de ensaio em aviary-I, as sementes de milho tratadas e as mudas com diferentes doses de repelentes de aves, grupo de controle em aviary-II, sementes não tratadas e mudas foram fornecidas por três horas no início da manhã. Em cada aviário, duas câmeras de circuito fechado também foram instaladas para monitorar as respostas comportamentais contra diferentes concentrações de ambos os repelentes químicos. A análise estatística mostrou que existiam variações altamente significativas (P<0,01) entre os grupos de teste e controle para sementes e mudas. Ao comparar os dois repelentes, detectaram-se diferenças significativas (P<0,05) e a antraquinona apresentou maior eficácia quando comparada ao metilantranilato, mas em mudas de milho, ambos os repelentes são iguais às propriedades repelentes. As diferenças não significantes (P>0,05) foram observadas em diferentes classificações de repelentes químicos naturais para sementes de milho, enquanto as variações significativas (P<0,05) foram observadas para as mudas de milho quando fornecidas aos pardais. Por um comportamento gravado em video, os pardais apresentaram manifestações de cabeça e vibrações de penas por consumo de sementes tratadas e mudas com maiores concentrações de repelentes de aves naturais.

Phenological stage effect on phenolic composition and repellent potential of Mentha pulegium against Tribolium castaneum and Lasioderma serricorne

Objective: To elucidate for the first time the phenological stage effect on polyphenol, flavonoid and proanthocyanidin contents of pennyroyal (Mentha pulegium) as well as their antioxidant capacities and insecticidal potentials against Tribolium castaneum and Lasioderma serricorne. Methods: Crude methanol extracts from pennyroyal (Mentha pulegium) aerial parts were evaluated for their antiradical, reducing power activities and repellent potentials against selected coleopteran insects during different phenological stages. Results: Phenolic contents of pennyroyal aerial parts and their antioxidant effects were significantly dependent on maturity stage of the plant. The maximum of phenol production was reached during the full flowering stage. Apigenin was the major phenol in Mentha pulegium with an amount of 6.01 mg/g of dry vegetable matter during this period. Nevertheless, at fructification stage, the highest antioxidant activity was not related to high phenolic content. The repulsive effect of pennyroyal extract showed that Lasioderma serricorne was more susceptible to pennyroyal extract than Tribolium castaneum with corresponding median repellent dose values of 0.124 and 0.006 mg/mL respectively. Moreover, great differences in insect repulsion depending on extract concentrations, exposure time and developmental stage was observed. For the lowest concentration (0.125 mg/mL), the repellent effect against Tribolium reached its maximum (90%) during the fructification stage (after 24 h of exposure) while this repellent effect was 80% during the vegetative stage. Conclusions: Due to the strong insecticidal potential of pennyroyal extracts, this study highlights the therapeutic properties of this plant and encourages its use as a safer, environmental-friendly and efficient insecticide in food industry.

Phenological stage effect on phenolic composition and repellent potential of Mentha pulegium against Tribolium castaneum and Lasioderma serricorne

Objective: To elucidate for the first time the phenological stage effect on polyphenol,flavonoid and proanthocyanidin contents of pennyroyal (Mentha pulegium) as well as their antioxidant capacities and insecticidal potentials against Tribolium castaneum and Lasioderma serricorne. Methods: Crude methanol extracts from pennyroyal (Mentha pulegium) aerial parts were evaluated for their antiradical, reducing power activities and repellent potentials against selected coleopteran insects during different phenological stages. Results: Phenolic contents of pennyroyal aerial parts and their antioxidant effects were significantly dependent on maturity stage of the plant. The maximum of phenol production was reached during the full flowering stage. Apigenin was the major phenol in Mentha pulegium with an amount of 6.01 mg/g of dry vegetable matter during this period. Nevertheless, at fructification stage,the highest antioxidant activity was not related to high phenolic content. The repulsive effect of pennyroyal extract showed that Lasioderma serricorne was more susceptible to pennyroyal extract than Tribolium castaneum with corresponding median repellent dose values of 0.124and 0.006 mg/mL respectively. Moreover, great differences in insect repulsion depending on extract concentrations, exposure time and developmental stage was observed. For the lowest concentration (0.125 mg/mL), the repellent effect against Tribolium reached its maximum (90％)during the fructification stage (after 24 h of exposure) while this repellent effect was 80％during the vegetative stage. Conclusions: Due to the strong insecticidal potential of pennyroyal extracts, this study highlights the therapeutic properties of this plant and encourages its use as a safer, environmental-friendly and efficient insecticide in food industry.

Repellent activity of essential oils extracted from five Artemisia species against Tribolium castaneum (Coleoptera: Tenebrionidae) / Actividad repelente de aceites esenciales extraídos de cinco especies de Artemisia contra Tribolium castaneum (Coleoptera: Tenebrionidae)

Artemisia genus (family Asteraceae) has been widely used as medicines and cosmetic. The chemical compositions of essential oils extracted from five Artemisia species (A. anethoides, A. giraldii, A. roxburghiana, A. rubripes and A. sacrorum) were analyzed and the repellent activities of five essential oils were investigated by testing percent repellency (PR) in petri dish against Tribolium castaneum. By GC-MS analysis, the common components of the five essential oils were eucalyptol (11.09%-50.05%), camphor (6.28%-33.10%), terpinen- 4-ol (2.46%-12.41%), ß-caryophyllene (0.63%-10.68%) and germacrene D (2.28%-10.01%). 3,3,6-trimethyl-1,4-heptadien-6-ol (11.72%), 2-isopropyl-5-methyl-3-cyclohexen-1-one (24.80%) and ß-farnesene (12.23%) were the characteristic compounds in essential oils of A. sacrorum, A. anethoides and A. rubripes respectively. The essential oils of five plants showed repellent activity against T. castaneum. The PR of others four essential oils were comparable with DEET expect for A. sacrorum. The results indicated that the essential oils of A. anethoides, A. giraldii, A. roxburghiana and A. rubripes had the potential to be developed as repellent for control of T. castaneum.

El género Artemisia (familia Asteraceae) ha sido ampliamente utilizado como medicamentos y cosméticos. Se analizaron las composiciones químicas de los aceites esenciales extraídos de cinco especies de Artemisia (A. anethoides, A. giraldii, A. roxburghiana, A. rubripes y A. sacrorum) y se investigaron las actividades repelentes de cinco aceites esenciales mediante la prueba de repelencia porcentual (PR) en placa de petri contra Tribolium castaneum. Por análisis GC-MS, los componentes comunes de los cinco aceites esenciales fueron eucaliptol (11,09% -50,05%), alcanfor (6,28% -33,10%), terpinen-4-ol (2,46% -12,41%), ß-cariofileno 0,63% -10,68%) y germacrén D (2,28% -10,01%). 3,3,6-trimetil-1,4-heptadien-6-ol (11,72%), 2-isopropil-5-metil-3-ciclohexen-1-ona (24,80%) y ß-farneseno (12,23%). Los compuestos característicos en los aceites esenciales de A. sacrorum, A. anethoides y A. rubripes respectivamente. Los aceites esenciales de cinco plantas mostraron actividad repelente contra T. castaneum. El PR de otros cuatro aceites esenciales eran comparables con DEET esperado para A. sacrorum. Los resultados indicaron que los aceites esenciales de A. anethoides, A. giraldii, A. roxburghiana y A. rubripes tienen el potencial de ser desarrollados como repelentes para el control de T. castaneum.

Histological Changes in the Cerebellum of Albino Rats after Inhalational Exposure to Pyrethroid Based Mosquito Repellent

Background: There has been an ever increasing use of liquid vaporizers as residential insecticides to get rid of the problem of mosquito and as a concern shown towards prevention of  increasing cases of vector borne diseases. Adverse impact of these chemicals are many  including giddiness, nausea, headache, body ache,  lethargy and dizziness but the current research on the safety of these chemical compounds is market driven and proper histological studies that can establish their toxic effects on cerebellar cortex which acts as higher  centre of coordination, balance and learning are  rare. Accordingly the present  study was planned  to look into the claim of safety of these inhalational compounds and to establish  the correlation, if any between pyrethroid based mosquito repellent inhalational use and the histological insult to the  cerebellum of  Albino rats. Methods: Total of twenty albino rats were marked  into groups marked as control and experimental. The exposure of experimental group was carried out  to 3.2% w/v prallethrin vapours for total of 12 hours in a day and continued for 180 days. The Albino rats in control group were put in similar surroundings but without exposure to any mosquito repellent. The albino rats  were killed after completing exposure of 180 days. The rats brain was dissected and  Cerebellum was taken out. Tissue processing and sectioning done and finally  stained wusing  haematoxylin, eosin and thionin stains. Results: Outer molecular and inner granular layer of cerebellum showed areas of degeneration with disruption and decreased density of cells in Purkinje cell layer. Conclusions: The findings of the  study do confirms that mosquito repellents  given  by inhalational route leads to toxic insult  as evident in this study on Albino rats  on long term  exposure of 180 days as shown by histological alterations  in the sections of cerebellar cortex of rat CNS.

Potential of natural repellents methylanthranilate and anthraquinone applied on maize seeds and seedlings against house sparrow (Passer domesticus) in captivity

Abstract Various bird pests caused severe economic losses to valuable crops and fruit orchards all over the world. Among the birds, house sparrow is also considered to cause heavy plunder, not only to seeds of crops but also seedlings especially in organic farming. In present study two bird repellents, methylanthranilate and anthraquinone tested against house sparrows on maize seeds and seedlings in aviary conditions. Trial group in aviary-I, the treated maize seeds and seedlings with different doses of both bird repellents, control group in aviary-II, untreated seeds and seedlings were provided for three hours in the early morning. In each aviary, two closed circuit cameras were also installed to monitor the behavioral responses against different concentrations of both chemical repellents. Statistical analysis showed that there existed highly significant (P 0.01) variations among the trial and control groups for seeds and seedlings. By comparing both repellents, significant (P 0.05) differences were detected and anthraquinone showed better efficacy when compared to methylanthranilate, but in maize seedlings both repellents equal repellent properties. Non-significant (P>0.05) differences were observed in different grading of both natural chemical repellents for maize seeds while significant (P 0.05) variations were noticed for maize seedlings when provided to sparrows. By videotaped behavior sparrows presented manifest head juddering and feather upsetting activities by consumption of treated seeds and seedlings with higher concentrations of both natural bird repellents.

Resumo Várias pragas de aves causaram graves perdas econômicas para cultivos valiosos e pomares de frutas em todo o mundo. Entre os pássaros, o pardal da casa também é considerado um grande saqueo, não só para as sementes das culturas, mas também para as mudas, especialmente na agricultura orgânica. No presente estudo, dois repelentes de aves, metilantranilato e antraquinona testados contra pardais de casa em sementes de milho e mudas em condições de aviário. O grupo de ensaio em aviary-I, as sementes de milho tratadas e as mudas com diferentes doses de repelentes de aves, grupo de controle em aviary-II, sementes não tratadas e mudas foram fornecidas por três horas no início da manhã. Em cada aviário, duas câmeras de circuito fechado também foram instaladas para monitorar as respostas comportamentais contra diferentes concentrações de ambos os repelentes químicos. A análise estatística mostrou que existiam variações altamente significativas (P 0,01) entre os grupos de teste e controle para sementes e mudas. Ao comparar os dois repelentes, detectaram-se diferenças significativas (P 0,05) e a antraquinona apresentou maior eficácia quando comparada ao metilantranilato, mas em mudas de milho, ambos os repelentes são iguais às propriedades repelentes. As diferenças não significantes (P>0,05) foram observadas em diferentes classificações de repelentes químicos naturais para sementes de milho, enquanto as variações significativas (P 0,05) foram observadas para as mudas de milho quando fornecidas aos pardais. Por um comportamento gravado em video, os pardais apresentaram manifestações de cabeça e vibrações de penas por consumo de sementes tratadas e mudas com maiores concentrações de repelentes de aves naturais.

Liposomal Microencapsulation of Rodent-repelling Agents onto Jute Burlaps: Assessment of Cytotoxicity and Rat Behavioral Test.

In Egypt, the world’s biggest wheat importer, about 7 to 10 percent of stored grains are damaged because of poor conditions of storage. Rodent invasion is considered as one of the main reasons that caused wheat grain damage. With respect of food safety, this work aims to treat the grain burlaps (containers) to rodent repellent. The rodent repellent agents was extracted from natural local resources. For the rodent repellent effectiveness, wheat burlaps are treated with rodent repelling agents using eco-friendly components. There are prepared using camphor oil, mint oil, and capsaicinoids (extracted from hot red pepper) as local resources to develop low cost and high-performance final product. The plan of work relies on two main axes; first, the experimental part in which burlap was treated for rodent repellent; second, testing and characterizing the treated samples for cytotoxicity and animal behavior test. The treatment was taking place by conventional pad-dry-cure technique.