RESUMEN
The current study investigated the synergistic effect of combinations containing deltamethrin (D), Eucalyptus essential oil (E), and the thyme essential oil component thymol (T), against a field population of Rhipicephalus annulatus in Egypt that was characterized to be resistant to D. Solutions of T, E, or TE at concentrations of 1.25-5% were combined with 5% deltamethrin at different dilutions (0.25-2 mL/L). Results of the adult immersion test used to estimate the in vitro acaricidal activity of these combinations at 5% yielded LC50 values for D, E-D, T-D, and TE-D of 3.87 mL/L, 3.89 mL/L, 0.14 mL/L, and 0.05 mL/L, respectively. Biochemical analyses using whole-body homogenate of ticks from the in vitro tests revealed that the lowest acetylcholinesterase and glutathione peroxidase activity, and the maximum lipid peroxidation were recorded in ticks treated with 5% TE-D. Glutathione content significantly decreased (p ≤ 0.05) in all treated ticks. Three groups, each containing five cross breed cattle naturally infested with R. annulatus from the same area where resistance to D was detected, were sprayed twice at two-week intervals using 1 mL/L of 5% solutions of D, T-D, or TE-D. Overall efficacy of the D, T-D, and TE-D sprays by day 30 post-treatment was 21.6, 88.3, and 95 %, respectively. Ticks collected from infested cattle three days after treatment with the D spray deposited egg masses that were able to hatch, deposited small masses of eggs unable to hatch when exposed to the T-D spray, and laid few eggs that didn't hatch when sprayed with the TE-D combination. Values for liver and kidney function parameters were comparable in cattle before and after treatment with the combination sprays tested. The TE-D spray overcame the insensitivity to D of this R. annulatus population in Egypt, which also highlighted the significant synergistic effect of thymol on the acaricidal activity of deltamethrin observed in vitro. Acaricidal activity of the TE-D combination apparently has deleterious effects on multiple tick systems involving inhibition of acetylcholinesterase, increased lipid peroxidation, and oxidative stress. These findings document that combinations of natural and synthetic products can be part of integrated management solutions to the problem with widespread resistance to pyrethroids like deltamethrin in populations of cattle ticks, including R. annulatus, around the world.
Asunto(s)
Enfermedades de los Bovinos/tratamiento farmacológico , Aceite de Eucalipto/uso terapéutico , Nitrilos/uso terapéutico , Piretrinas/uso terapéutico , Rhipicephalus/efectos de los fármacos , Timol/uso terapéutico , Acaricidas/uso terapéutico , Animales , Antioxidantes/metabolismo , Biomarcadores , Bovinos , Enfermedades de los Bovinos/parasitología , Aceite de Eucalipto/química , Femenino , Nitrilos/administración & dosificación , Estrés Oxidativo/efectos de los fármacos , Sinergistas de Plaguicidas , Piretrinas/administración & dosificación , Timol/administración & dosificación , Infestaciones por Garrapatas/tratamiento farmacológico , Infestaciones por Garrapatas/veterinariaRESUMEN
Pyrethroid resistance is a significant threat to agricultural, urban and public health pest control activities. Because economic incentives for the production of novel active ingredients for the control of public health pests are lacking, this field is particularly affected by the potential failure of pyrethroid-based insecticides brought about by increasing pyrethroid resistance. As a result, innovative approaches are desperately needed to overcome insecticide resistance, particularly in mosquitoes that transmit deadly and debilitating pathogens. Numerous studies have demonstrated the potential of plant essential oils to enhance the efficacy of pyrethroids. The toxicity of pyrethroids combined with plant oils is significantly greater than the baseline toxicity of either oils or pyrethroids applied alone, which suggests there are synergistic interactions between components of these mixtures. The present study examined the potential of eight plant essential oils applied in one of two concentrations (1% and 5%) to enhance the toxicity of various pyrethroids (permethrin, natural pyrethrins, deltamethrin and ß-cyfluthrin). The various plant essential oils enhanced the pyrethroids to differing degrees. The levels of enhancement provided by combinations of plant essential oils and pyrethroids in comparison with pyrethroids alone were calculated and synergistic outcomes characterized. Numerous plant essential oils significantly synergized a variety of pyrethroids; type I pyrethroids were synergized to a greater degree than type II pyrethroids. Eight plant essential oils significantly enhanced 24-h mortality rates provided by permethrin and six plant essential oils enhanced 24-h mortality rates obtained with natural pyrethrins. By contrast, only three plant essential plants significantly enhanced the toxicity of deltamethrin and ß-cyfluthrin. Of the plant essential oils that enhanced the toxicity of these pyrethroids, some produced varying levels of synergism and antagonism. Geranium, patchouli and Texas cedarwood oils produced the highest levels of synergism, displaying co-toxicity factors of > 100 in some combinations. To assess the levels of enhancement and synergism of other classes of insecticide, malathion was also applied in combination with the plant oils. Significant antagonism was provided by a majority of the plant essential oils applied in combination with this insecticide, which suggests that plant essential oils may act to inhibit the oxidative activation processes within exposed adult mosquitoes.
Asunto(s)
Aedes , Insecticidas , Malatión , Aceites Volátiles , Sinergistas de Plaguicidas , Piretrinas , Animales , Relación Dosis-Respuesta a Droga , Femenino , Resistencia a los InsecticidasRESUMEN
BACKGROUND: The increase in resistance of head lice to neurotoxic pediculicides and public concern over their safety has led to an increase in alternative treatments, many of which are poorly researched or even untested. METHODS: A multicentre, randomised, assessor-blind, parallel-group trial (Trial 1) was conducted to compare the safety and efficacy of a head lice treatment containing Australian eucalyptus oil and Leptospermum petersonii (EO/LP solution; applied thrice with 7-day intervals between applications) with a neurotoxic treatment containing pyrethrins and piperonyl butoxide (P/PB mousse; applied twice with a 7-day interval) in children. A single-blind, open trial (Trial 2) was conducted to assess the efficacy of EO/LP solution following a single application. In addition, skin irritancy and sensitisation tests using EO/LP solution were performed in adults and children. In vitro tests were performed to further assess the ovicidal and pediculicidal efficacy of EO/LP solution. RESULTS: EO/LP solution was found to be more than twice as effective in curing head lice infestation as P/PB mousse in per-protocol participants (Trial 1; 83% vs 36%, P < 0.0001), and was also found to be 100% pediculicidal following a single application (Trial 2). Adverse events were limited to transient itching, burning or stinging. Further skin testing with the EO/LP solution reported no irritation or sensitisation in adults, or irritation in children. In vitro exposure of lice and eggs to the EO/LP solution resulted in 100% mortality. CONCLUSION: The efficacy, safety and relative ease of use of the EO/LP solution make it a viable alternative in treating head lice.
Asunto(s)
Eucalyptus , Leptospermum , Infestaciones por Piojos/tratamiento farmacológico , Aceites Volátiles/uso terapéutico , Pediculus , Aceites de Plantas/uso terapéutico , Dermatosis del Cuero Cabelludo/diagnóstico por imagen , Adulto , Anciano , Animales , Preescolar , Femenino , Humanos , Lactante , Insecticidas/uso terapéutico , Masculino , Persona de Mediana Edad , Aceites Volátiles/efectos adversos , Óvulo/efectos de los fármacos , Pediculus/efectos de los fármacos , Sinergistas de Plaguicidas/uso terapéutico , Butóxido de Piperonilo/uso terapéutico , Aceites de Plantas/efectos adversos , Piretrinas/uso terapéutico , Dermatosis del Cuero Cabelludo/parasitología , Método Simple CiegoRESUMEN
Piperonyl butoxide is a semi-synthetic synergist for natural pyrethrum and synthetic pyrethroid insecticides in phytochemicals and biocides. As such it is used in large quantities for crop treatments, stored grain protection, disinfestation of grain storage facilities and indoor uses. Piperonyl butoxide is consequently a regular contaminant in stored grains, and subsequently in corresponding cereal food products and meat via feed uses. Therefore it is regularly monitored and its MRL is ongoing a reassessment. It is also considered as a possible human carcinogen and a suspected endocrine disruptor. For all these reasons and considerations most of the countries have already banned its use in Organic Farming as France in 2017. Thus, ecological substitution of with biorational and sustainable solutions is required. Vegetable oils have been described as exhibiting similar potency and synergistic effects. We have reviewed the literature and have proceeded to ecotoxicological efficacy tests in order to determine the best and most durable substitution candidates. Sesame and rape seed oil were determined to be the most efficient.
Asunto(s)
Insecticidas/química , Sinergistas de Plaguicidas/química , Butóxido de Piperonilo/química , Aceites de Plantas/química , Piretrinas/química , Animales , Chrysanthemum cinerariifolium , Francia , Humanos , Insectos/efectos de los fármacos , Insecticidas/síntesis química , Insecticidas/farmacología , Piretrinas/síntesis química , Piretrinas/farmacologíaRESUMEN
The migration and accumulation of octachlorodipropyl ether (OCDPE) in soil-tea systems were investigated using a gas chromatography-electron capture detector (GC-ECD) method in young and old tea gardens. When the residual concentration of OCDPE was 100 g a.i. hm-2 in soils, the peak concentrations of OCDPE in fresh leaves of young and old tea plants were 0.365 mg/kg and 0.144 mg/kg, taking 45 days and 55 days, respectively. Equations for the accumulation curves of OCDPE in fresh leaves of young and old tea plants were Ct = 0.0227e0.0566t (R² = 0.9154) and Ct = 0.0298e-0.0306t (R² = 0.7156), and were Ct = 3.8435e0.055t (R² = 0.9698) and Ct = 1.5627e-0.048t (R² = 0.9634) for dissipation curves, with a half-life of 14.4 days and 12.6 days, respectively. These results have practical guiding significance for controlling tea food safety.
Asunto(s)
Camellia sinensis/metabolismo , Éteres/análisis , Sinergistas de Plaguicidas/análisis , Hojas de la Planta/metabolismo , Contaminantes del Suelo/análisis , Cromatografía de Gases , Monitoreo del Ambiente , Éteres/metabolismo , Inocuidad de los Alimentos , Jardines , Semivida , Sinergistas de Plaguicidas/metabolismo , Contaminantes del Suelo/metabolismoRESUMEN
Although screening for new and reliable sources of botanical insecticides remains important, finding ways to improve the efficacy of those already in use through better understanding of their modes-of-action or metabolic pathways, or by improving formulations, deserves greater attention as the latter may present lesser regulation hurdles. Metabolic processing of citral (a combination of the stereoisomers geranial and neral), a main constituent of lemongrass (Cymbopogon citratus) essential oil has not been previously examined in insects. To address this, we investigated insecticidal activities of lemongrass oil and citral, as well as the metabolism of citral in larvae of the cabbage looper, Trichoplusia ni, in associations with well-known enzyme inhibitors. Among the inhibitors tested, piperonyl butoxide showed the highest increase in toxicity followed by triphenyl phosphate, but no synergistic interaction between the inhibitors was observed. Topical application of citral to fifth instar larvae produced mild reductions in food consumption, and frass analysis after 24h revealed geranic acid (99.7%) and neric acid (98.8%) as major metabolites of citral. Neither citral nor any other metabolites were found following in vivo analysis of larvae after 24h, and no significant effect of enzyme inhibitors was observed on diet consumption or citral metabolism.
Asunto(s)
Inhibidores Enzimáticos del Citocromo P-450/farmacología , Insecticidas/toxicidad , Monoterpenos , Mariposas Nocturnas/efectos de los fármacos , Organofosfatos/farmacología , Butóxido de Piperonilo/farmacología , Monoterpenos Acíclicos , Animales , Sistema Enzimático del Citocromo P-450/metabolismo , Esterasas/antagonistas & inhibidores , Esterasas/metabolismo , Heces/química , Proteínas de Insectos/antagonistas & inhibidores , Proteínas de Insectos/metabolismo , Insecticidas/farmacocinética , Larva/efectos de los fármacos , Larva/crecimiento & desarrollo , Larva/metabolismo , Monoterpenos/farmacocinética , Monoterpenos/toxicidad , Mariposas Nocturnas/crecimiento & desarrollo , Mariposas Nocturnas/metabolismo , Sinergistas de Plaguicidas/farmacología , Aceites de Plantas/toxicidad , Terpenos/toxicidadRESUMEN
The dissipation behavior of octachlorodipropyl ether (OCDPE) residues in fresh tea shoots and in tea prepared under field conditions was investigated, and the transfer of residues from brewed tea to tea infusion was determined. OCDPE levels in tea shoots, prepared tea, tea infusion, and spent tea leaves were determined using a sensitive and simple method. The dissipation of OCDPE is fairly slow in tea shoots and prepared tea, with half-life values of 5.10 and 5.46 days, respectively. The degradation rates of OCDPE residues in tea processing were 23.9-43.1 %. The terminal residues of OCDPE in tea shoots and prepared tea samples after 20 and 30 days of OCDPE application were higher than 0.01 mg/kg. However, OCDPE's transfer rates from brewed tea to tea infusion were only 6.0-14.8 %. Further studies on risk assessment of OCDPE residue in tea on the basis of the relationship of OCDPE in prepared tea and infusion are warranted.
Asunto(s)
Camellia sinensis/metabolismo , Monitoreo del Ambiente/métodos , Éteres/análisis , Residuos de Plaguicidas/análisis , Sinergistas de Plaguicidas/análisis , Té/química , Camellia sinensis/química , Camellia sinensis/crecimiento & desarrollo , Éteres/metabolismo , Contaminación de Alimentos/análisis , Residuos de Plaguicidas/metabolismo , Sinergistas de Plaguicidas/metabolismo , Brotes de la Planta/química , Brotes de la Planta/crecimiento & desarrollo , Brotes de la Planta/metabolismoRESUMEN
Insecticide synergists biochemically inhibit insect metabolic enzyme activity and are used both to increase the effectiveness of insecticides and as a diagnostic tool for resistance mechanisms. Considerable attention has been focused on identifying new synergists from phytochemicals with recognized biological activities, specifically enzyme inhibition. Jack pine (Pinus banksiana Lamb.), black spruce (Picea mariana (Mill.) BSP.), balsam fir (Abies balsamea (L.) Mill.), and tamarack larch (Larix laricina (Du Roi) Koch) have been used by native Canadians as traditional medicine, specifically for the anti-inflammatory and antioxidant properties based on enzyme inhibitory activity. To identify the potential allelochemicals with synergistic activity, ethanol crude extracts and methanol/water fractions were separated by Sephadex LH-20 chromatographic column and tested for in vitro glutathione S-transferase (GST) inhibition activity using insecticide-resistant Colorado potato beetle, Leptinotarsa decemlineata (Say) midgut and fat-body homogenate. The fractions showing similar activity were combined and analyzed by ultra pressure liquid chromatography-mass spectrometry. A lignan, (+)-lariciresinol 9'-p-coumarate, was identified from P. mariana cone extracts, and L. laricina and A. balsamea bark extracts. A flavonoid, taxifolin, was identified from P. mariana and P. banksiana cone extracts and L. laricina bark extracts. Both compounds inhibit GST activity with taxifolin showing greater activity compared to (+)-lariciresinol 9'-p-coumarate and the standard GST inhibitor, diethyl maleate. The results suggested that these compounds can be considered as potential new insecticide synergists.
Asunto(s)
Escarabajos/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Glutatión Transferasa/antagonistas & inhibidores , Sinergistas de Plaguicidas , Extractos Vegetales/farmacología , Tracheophyta/química , Animales , Escarabajos/enzimología , Inhibidores Enzimáticos/química , Cuerpo Adiposo/efectos de los fármacos , Cuerpo Adiposo/enzimología , Tracto Gastrointestinal/efectos de los fármacos , Tracto Gastrointestinal/enzimología , Glutatión Transferasa/metabolismo , Resistencia a los Insecticidas , Insecticidas/farmacología , Larva/efectos de los fármacos , Lignanos/farmacología , Extractos Vegetales/química , Quercetina/análogos & derivados , Quercetina/farmacologíaRESUMEN
BACKGROUND: A study was undertaken to determine the efficacy of seven natural compounds compared with piperonyl butoxide (PBO) in synergising pyrethrum, with the intention of formulating an effective natural synergist with pyrethrum for use in the organic crop market. RESULTS: Discriminating dose bioassays showed PBO to be significantly more effective at synergising pyrethrum in houseflies than the seven natural compounds tested, causing 100% mortality in insecticide-susceptible WHO and resistant 381zb strains of housefly. The most effective natural synergists against WHO houseflies were dillapiole oil, grapefruit oil and parsley seed oil, with 59, 50 and 41% mortality respectively, compared with 18% mortality with unsynergised pyrethrum. Against 381zb houseflies, the most effective natural synergists were parsley seed oil and dillapiole oil. Esterase inhibition by the natural compounds and PBO in vitro showed no correlation with pyrethrum synergism in vivo, whereas the inhibition of oxidases in vitro more closely correlated with pyrethrum synergism in vivo. CONCLUSION: Dillapiole oil and parsley seed oil showed the greatest potential as pyrethrum synergists. PBO remained the most effective synergist, possibly owing to its surfactant properties, enhancing penetration of pyrethrins. The results suggest the involvement of oxidases in pyrethroid resistance in houseflies, with the efficacy of synergists showing a high correlation with inhibition of oxidases.
Asunto(s)
Moscas Domésticas , Aceites Volátiles , Sinergistas de Plaguicidas , Extractos Vegetales , Piretrinas , Animales , Inhibidores de la Colinesterasa , Femenino , Control de Insectos , Masculino , Butóxido de PiperoniloRESUMEN
BACKGROUND: In recent years, several studies have shown the impact of adjuvants on the characteristics of herbicide deposits on leaf surfaces. Until now, most studies have addressed the distribution of active ingredients (AIs), whereas few experiments have focused on the location of the adjuvants. The objective of this study was a systematic examination of the particle distribution profile of both the AI (glyphosate, Gly) and the adjuvants after the application of sessile microdroplets on hydrophobic (Teflon) and hydrophilic (glass and aluminium) model surfaces. RESULTS: The association degree (AD) was surface dependent and specific for the tested adjuvants. In general, the rather hydrophobic adjuvant RSO 5 showed decreasing AD with Gly at increasing relative humidity (RH) levels. The rather hydrophilic RSO 60 adjuvant displayed higher AD between the compounds at a higher RH. A high concentration of the adjuvant reduced the AD for both of the RSO adjuvants evaluated. CONCLUSION: The combination of surface properties, the type of adjuvant and the relative humidity determines the degree of association between Gly and the adjuvants. The present results suggest that the interaction between the AI and an adjuvant determines whether spatial separation occurs, whereas physical processes (e.g. capillary particle movement, inward and outward Marangoni flows and the evaporation rate) are decisive for the extent of the separation. Coffee-ring structures were formed exclusively with the adjuvant+Gly mixtures, whereas Gly alone formed either one big deposit or several small islands distributed within the droplet footprint.
Asunto(s)
Glicina/análogos & derivados , Herbicidas/química , Sinergistas de Plaguicidas/química , Aceites de Plantas/química , Microanálisis por Sonda Electrónica , Ácidos Grasos Monoinsaturados , Glicina/química , Humedad , Interacciones Hidrofóbicas e Hidrofílicas , Microscopía Electrónica de Rastreo , Aceite de Brassica napus , GlifosatoRESUMEN
BACKGROUND: Glyphosate is a non-selective, foliar-applied, systemic herbicide that kills weeds by inhibiting the synthesis of 5-enolpyruvylshikimate-3-phosphate synthase. Urea phosphate (UPP), made by the reaction of urea with phosphoric acid, was applied as an adjuvant for glyphosate in this study. Experiments in the greenhouse and the field were conducted to determine the effects of UPP by comparing the efficacies of glyphosate plus UPP, glyphosate plus 1-aminomethanamide dihydrogen tetraoxosulfate (AMADS) and Roundup. RESULTS: The optimum concentration of UPP in glyphosate solution was 2.0% when UPP was used as an adjuvant. The ED50 values for glyphosate-UPP were 291.7 and 462.4 g AI ha(-1) in the greenhouse and the field respectively, while the values for Roundup were 448.2 and 519.6 g AI ha(-1). The ED50 values at 2 weeks after treatment (WAT) and 3 WAT were lowered when UPP was used as an adjuvant in the greenhouse and field study, and the glyphosate+UPP was absorbed over a 2 week period. UPP may increase the efficacy by causing severe cuticle disruption or accelerating the initial herbicide absorption. The result also showed that UPP could reduce the binding behaviour of Ca2+ to glyphosate. CONCLUSION: The application of UPP as an adjuvant could increase the efficacy of glyphosate and make it possible to achieve effective control of weeds with glyphosate at lower dose. Moreover, UPP showed less causticity to spraying tools and presented less of a health hazard. Therefore, UPP is accepted as being a new, effective and environmentally benign adjuvant for glyphosate.
Asunto(s)
Formamidas/administración & dosificación , Glicina/análogos & derivados , Herbicidas , Sinergistas de Plaguicidas/administración & dosificación , Ácidos Fosfóricos/administración & dosificación , Malezas , Urea/administración & dosificación , Cloruro de Calcio , GlifosatoRESUMEN
Shown antimicrotrubules activity of new 2,6-dinitroaniline compounds. Investigated their ability on apoptotic processes in a plant cell when used as a composition with inhibitors of acetyl-CoA carboxylase.
Asunto(s)
Compuestos de Anilina/química , Antimitóticos/química , Herbicidas/química , Sinergistas de Plaguicidas/química , Compuestos de Anilina/farmacología , Antimitóticos/farmacología , Apoptosis/efectos de los fármacos , Citoplasma/efectos de los fármacos , Citoplasma/ultraestructura , Fragmentación del ADN/efectos de los fármacos , Herbicidas/farmacología , Hordeum/efectos de los fármacos , Hordeum/ultraestructura , Etiquetado Corte-Fin in Situ , Microscopía Confocal , Microtúbulos/efectos de los fármacos , Microtúbulos/ultraestructura , Estructura Molecular , Cebollas/efectos de los fármacos , Cebollas/ultraestructura , Sinergistas de Plaguicidas/farmacología , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/ultraestructura , Brotes de la Planta/efectos de los fármacos , Brotes de la Planta/ultraestructura , Raphanus/efectos de los fármacos , Raphanus/ultraestructuraRESUMEN
BACKGROUND: There are many different types of pediculicides available OTC in Australia. In this study we compare the efficacy and safety of three topical pediculicides: a pediculicide containing melaleuca oil (tea tree oil) and lavender oil (TTO/LO); a head lice "suffocation" product; and a product containing pyrethrins and piperonyl butoxide (P/PB). METHOD: This study was a randomised, assessor-blind, comparative, parallel study of 123 subjects with live head lice. The head lice products were applied according to the manufacturer's instructions (the TTO/LO product and the "suffocation" product were applied three times at weekly intervals according to manufacturers instructions (on Day 0, Day 7 and Day 14) and the P/PB product was applied twice according to manufacturers instructions (on Day 0 and Day 7)). The presence or absence of live lice one day following the last treatment was determined. RESULTS: The percentage of subjects who were louse-free one day after the last treatment with the product containing tea tree oil and lavender oil (41/42; 97.6%) and the head lice "suffocation" product (40/41, 97.6%) was significantly higher compared to the percentage of subjects who were louse-free one day after the last treatment with the product containing pyrethrins and piperonyl butoxide (10/40, 25.0%; adj. p < 0.0001). CONCLUSION: The high efficacy of the TTO/LO product and the head lice "suffocation" product offers an alternative to the pyrethrins-based product. TRIAL REGISTRATION: The study was entered into the Australian/New Zealand Clinical Trial Registry, ACTRN12610000179033.
Asunto(s)
Infestaciones por Piojos/tratamiento farmacológico , Aceites Volátiles/administración & dosificación , Pediculus/efectos de los fármacos , Butóxido de Piperonilo/administración & dosificación , Aceites de Plantas/administración & dosificación , Piretrinas/administración & dosificación , Aceite de Árbol de Té/administración & dosificación , Animales , Antiinfecciosos Locales/administración & dosificación , Antiinfecciosos Locales/efectos adversos , Asfixia , Niño , Preescolar , Método Doble Ciego , Humanos , Insecticidas/administración & dosificación , Insecticidas/efectos adversos , Lavandula , Aceites Volátiles/efectos adversos , Sinergistas de Plaguicidas/administración & dosificación , Sinergistas de Plaguicidas/efectos adversos , Butóxido de Piperonilo/efectos adversos , Aceites de Plantas/efectos adversos , Piretrinas/efectos adversos , Aceite de Árbol de Té/efectos adversos , Resultado del TratamientoRESUMEN
Effect of a known synergist piperonyl butoxide on the toxicity of steam distillate essential oils of Jamarosa (Cymbopogan nardus), Pacholli (Pogostemon pacholli), Basil (Ocimum basilicum), and Peppermint (Mentha pipreta) plant species against Anopheles stephensi larvae were evaluated. The purpose of the present study was to identify the insecticidal potential of these oils against mosquito larvae. The Piperonyl Butoxide (PBO) was used to enhance the activity of these oils with the aim of developing essential oil based formulations. The bioassays of these oils with and without PBO were performed against late 3rd instar larvae of An. stephensi. The LC50 values against An. stephensi were 44.19 ppm for Ocimum basilicum oil, followed by, Mentha pipreta, Cymbopogan nardus, and Pogostemon pacholli oil which gave LC50 values above 250 ppm. Thus in the present study the Ocimum basilicum oil was found to be most effective, whereas Pogostemon pacholli oil was found to least effective against mosquitoes for larvicidal action. The effect of synergist PBO led to the enhancement of toxicity of oils, the LC50 value for Ocimum basilicum were reduced from 44.19 ppm to 23.87 ppm. Similarly the oil of Pogostemon pacholli showed most significant results where the LC50 value was > 250 ppm it was reduced to 50 ppm with PBO.
Asunto(s)
Anopheles/efectos de los fármacos , Aceites Volátiles/farmacología , Sinergistas de Plaguicidas/farmacología , Butóxido de Piperonilo/farmacología , Aceites de Plantas/farmacología , Animales , Cymbopogon/química , Humanos , Insectos Vectores/efectos de los fármacos , Lamiaceae/química , Larva/efectos de los fármacos , Dosificación Letal Mediana , Malaria/prevención & control , Control de Mosquitos/métodos , Ocimum basilicum/química , Aceites Volátiles/química , Aceites de Plantas/químicaRESUMEN
Reaction between 4-formyl-2-methoxyphenyl 4,5-dichloroisothiazole-3-carboxylate with various aromatic amines led to azomethins 2-7 formation. By treatment of azomethins 2-7 with sodium triacetoxyborohydride corresponding amines 8-11 were obtained. During the bioassays of new vanillin derivatives in mixtures with insecticides remarkable synergetic effect was discovered.
Asunto(s)
Benzaldehídos/síntesis química , Escarabajos/crecimiento & desarrollo , Insecticidas/síntesis química , Sinergistas de Plaguicidas/síntesis química , Tiazoles/síntesis química , Animales , Benzaldehídos/química , Bioensayo , Insecticidas/química , Espectroscopía de Resonancia Magnética , Sinergistas de Plaguicidas/química , Espectrofotometría Infrarroja , Tiazoles/químicaRESUMEN
Previous studies demonstrated that chronic dermal exposure to the pesticide adjuvant (surfactant), Toximul (Tox), has significant detrimental effects on hepatic lipid metabolism. This study demonstrated that young mice dermally exposed to Tox for 12 days have significant increases in expression of peroxisomal acyl-CoA oxidase (mRNA and protein), bifunctional enzyme (mRNA) and thiolase (mRNA), as well as the P450 oxidizing enzymes Cyp4A10 and Cyp4A14 (mRNA and protein). Tox produced a similar pattern of increases in wild type adult female mice but did not induce these responses in PPARalpha-null mice. These data support the hypothesis that Tox, a heterogeneous blend of nonionic and anionic surfactants, modulates hepatic metabolism at least in part through activation of PPARalpha. Notably, all three groups of Tox-treated mice had increased relative liver weights due to significant accumulation of lipid. This could be endogenous in nature and/or a component(s) of Tox or a metabolite thereof. The ability of Tox and other hydrocarbon pollutants to induce fatty liver despite being PPARalpha agonists indicates a novel consequence of exposure to this class of chemicals, and may provide a new understanding of fatty liver in populations with industrial exposure.
Asunto(s)
Hígado/efectos de los fármacos , Hígado/metabolismo , PPAR alfa/metabolismo , 3-Hidroxiacil-CoA Deshidrogenasas/metabolismo , Acetil-CoA C-Aciltransferasa/metabolismo , Acil-CoA Oxidasa , Animales , Citocromo P-450 CYP4A/genética , Citocromo P-450 CYP4A/metabolismo , Enoil-CoA Hidratasa/metabolismo , Ácidos Grasos/metabolismo , Hígado Graso/inducido químicamente , Hígado Graso/patología , Femenino , Regulación de la Expresión Génica/efectos de los fármacos , Isomerasas/metabolismo , Hígado/anatomía & histología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos ICR , Ratones Noqueados , Complejos Multienzimáticos/metabolismo , Compuestos Orgánicos/toxicidad , Oxidorreductasas/metabolismo , PPAR alfa/agonistas , PPAR alfa/genética , Enzima Bifuncional Peroxisomal , Sinergistas de Plaguicidas/toxicidad , Tensoactivos/toxicidadRESUMEN
In a study aimed at finding environmentally benign adjuvants for glyphosate, ethoxylates of rapeseed oil and of methylated rapeseed oil were synthesized, with ethylene oxide (EO) content up to 40 and 8 respectively. They had less influence on spray retention by barley shoots than ethoxylated (15 EO) tallow amine (ETA). At 10 g L(-1), ethoxylated rapeseed oil with 30 or 40 EO and ethoxylated methylated rapeseed oil with 6 or 8 EO promoted glyphosate uptake by barley leaves to a greater extent than ETA at the same concentration. However, uptake rates were similar when the concentration was lowered to 2.8 and 3.1 g L(-1) for rapeseed oil derivatives and ETA respectively. In the case of ethoxylated methylated rapeseed oil with 8 EO (MeOil-8), glyphosate uptake increased when MeOil-8 concentration was raised from 5 to 10 g L(-1). In bioassays under controlled conditions, ethoxylated rapeseed oil with 40 EO (Oil-40) and MeOil-8 were slightly less effective than ETA in favouring the efficacy of glyphosate on barley. The same was found on ryegrass. However, both rapeseed oil derivatives compared well with glyphosate formulants such as ethoxylated diethylamine and alkyl ethoxy phosphate. In one field experiment, the efficacy of glyphosate in the presence of Oil-40, MeOil-8 or ETA was comparable with that of a commercial formulation. In another trial, MeOil-8 was as effective as ETA, but Oil-40 performed less well. It is concluded that ethoxylates of rapeseed oil and of methylated rapeseed oil are a promising chemistry for glyphosate adjuvants, provided that their ethylene oxide content is high.
Asunto(s)
Óxido de Etileno/química , Glicina/análogos & derivados , Herbicidas/administración & dosificación , Sinergistas de Plaguicidas/química , Aceites de Plantas/química , Ácidos Grasos Monoinsaturados , Glicina/administración & dosificación , Glicina/farmacocinética , Herbicidas/farmacocinética , Hojas de la Planta/metabolismo , Aceite de Brassica napus , GlifosatoRESUMEN
Piperonyl butoxide (PBO), alpha-[2-(2-butoxyethoxy)ethoxy]-4,5-methylene-dioxy-2-propyltoluene, is widely used as a synergist for pyrethrins. In order to clarify the possible mechanism of non-genotoxic hepatocarcinogenesis induced by PBO, molecular pathological analyses consisting of low-density microarray analysis and real-time reverse transcriptase (RT)-PCR were performed in male ICR mice fed a basal powdered diet containing 6000 or 0 ppm PBO for 1, 4, or 8 weeks. The animals were sacrificed at weeks 1, 4, and 8, and the livers were histopathologically examined and analyzed for gene expression using the microarray at weeks 1 and 4 followed by real-time RT-PCR at each time point. Reactive oxygen species (ROS) products were also measured using liver microsomes. At each time point, the hepatocytes of PBO-treated mice showed centrilobular hypertrophy and increased lipofuscin deposition in Schmorl staining. The ROS products were significantly increased in the liver microsomes of PBO-treated mice. In the microarray analysis, the expression of oxidative and metabolic stress-related genes--cytochrome P450 (Cyp) 1A1, Cyp2A5 (week 1 only), Cyp2B9, Cyp2B10, and NADPH-cytochrome P450 oxidoreductase (Por) was over-expressed in mice given PBO at weeks 1 and 4. Fluctuations of these genes were confirmed by real-time RT-PCR in PBO-treated mice at each time point. In additional real-time RT-PCR, the expression of Cyclin D1 gene, key regulator of cell-cycle progression, and Xrcc5 gene, DNA damage repair-related gene, was significantly increased at each time point and at week 8, respectively. These results suggest the possibility that PBO has the potential to generate ROS via the metabolic pathway and to induce oxidative stress, including oxidative DNA damage, resulting in the induction of hepatocellular tumors in mice.
Asunto(s)
Carcinógenos , Neoplasias Hepáticas/inducido químicamente , Sinergistas de Plaguicidas/toxicidad , Butóxido de Piperonilo/toxicidad , Animales , Antígenos Nucleares/biosíntesis , Antígenos Nucleares/genética , Peso Corporal/efectos de los fármacos , Ciclina D1/biosíntesis , Ciclina D1/genética , Sistema Enzimático del Citocromo P-450/metabolismo , Daño del ADN/efectos de los fármacos , Cartilla de ADN , ADN Complementario/biosíntesis , ADN Complementario/genética , Proteínas de Unión al ADN/biosíntesis , Proteínas de Unión al ADN/genética , Dieta , Ingestión de Alimentos/efectos de los fármacos , Isoenzimas/metabolismo , Autoantígeno Ku , Hígado/patología , Neoplasias Hepáticas/patología , Masculino , Ratones , Ratones Endogámicos ICR , Análisis de Secuencia por Matrices de Oligonucleótidos , Tamaño de los Órganos/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
The herbicidal action of Betanal Express (BPAM) on Chine jute (Abutilon theophrasti) weed was studied in the presence of a new plant growth regulator of urea type, N-phenyl-N-(1,2,4-triazol-4-yl)urea (PhenylTriazolylUrea, PTU). In the past years, Chine jute has become a major limiting factor in sugar beet production in the southern Russia due to its resistance to BPAM which is an essential herbicide widely used for sugar beet protection. When PTU was added to BPAM, the combination appeared to be more effective than the herbicide alone. The influence of phytohormone PTU was observed at very low application rate of 20-100 g/ha, thus herbicide dose in the ecosystem was reduced. The main visual signs of herbicidal action of the combination BPAM + PTU on Chine jute were inhibition of growth of overground plant and stem, leaves changes and sharp inhibition of root growth. No sugar beet injury was observed when this tank mixture was used. It was found that enhanced performance of the novel herbicide formulation is determined by increased herbicidal action of Ethofumesate, one of the active ingredients of BPAM.