ABSTRACT
BACKGROUND: Black widow spider (L. tredecimguttatus) has toxic components not only in the venomous glands, but also in other parts of the body and its eggs. It is biologically important to investigate the molecular basis of the egg toxicity. RESULTS: In the present work, an aqueous extract was prepared from the eggs of the spider and characterized using multiple physiological and biochemical strategies. Gel electrophoresis and mass spectrometry demonstrated that the eggs are rich in high-molecular-mass proteins and the peptides below 5 kDa. The lyophilized extract of the eggs had a protein content of 34.22% and was shown to have a strong toxicity towards mammals and insects. When applied at a concentration of 0.25 mg/mL, the extract could completely block the neuromuscular transmission in mouse isolated phrenic nerve-hemidiaphragm preparations within 12.0 ± 1.5 min. Using whole-cell patch-clamp technique, the egg extract was demonstrated to be able to inhibit the voltage-activated Na+, K+and Ca2+ currents in rat DRG neurons. In addition, the extract displayed activities of multiple hydrolases. Finally, the molecular basis of the egg toxicity was discussed. CONCLUSIONS: The eggs of black widow spiders are rich in proteinous compounds particularly the high-molecular-mass proteins with different types of biological activity The neurotoxic and other active compounds in the eggs are believed to play important roles in the eggs' toxic actions.
Subject(s)
Animals , Mice , Rats , Ovum/chemistry , Tissue Extracts/chemistry , Black Widow Spider/chemistry , Arthropod Proteins/toxicity , Ovum/physiology , Phrenic Nerve/drug effects , Tissue Extracts/toxicity , Calcium Channels/drug effects , Cockroaches/drug effects , Potassium Channels, Voltage-Gated/drug effects , Animal Shells/physiology , Animal Shells/chemistry , Arthropod Proteins/isolation & purification , Voltage-Gated Sodium Channels/drug effects , Ganglia, Spinal/drug effectsABSTRACT
Seven commercial essential oils extracted from the plant species Boesenbergia rotunda (L.) Mansf., Citrus hystrix DC., Curcuma longa L., Litsea cubeba (Lour.) Pers., Piper nigrum L., Psidium guajava L. and Zingiber officinale Roscoe, and naphthalene as a control, were evaluated for repellent activity against the three cockroach species Periplaneta americana (L.), Blattella germanica (L.) and Neostylopyga rhombifolia (Stoll) under laboratory conditions. The essential oil derived from Citrus hystrix showed the best repellency over other candidate essential oils and naphthalene. The essential oil of Citrus hystrix exhibited complete repellency (100%) against P. americana and B. germanica, and also showed the highest repellency (among the essential oils tested) of about 87.5% against N. rhombifolia under laboratory conditions. In the field, Citrus hystrix essential oil formulated as a 20% active ingredient in ethanol and some additives provided satisfactory repellency of up to 86% reduction in cockroaches, mostly P. americana and N. rhombifolia with a residual effect lasting a week after treatment. Citrus hystrix essential oil has good potential for being used as a cockroach repellent. Further improvements in efficacy and residual activity may be realized with appropriate formulations.
Subject(s)
Animals , Citrus/chemistry , Cockroaches/drug effects , Curcuma/chemistry , Zingiber officinale/chemistry , Insect Repellents/chemistry , Litsea/chemistry , Oils, Volatile/chemistry , Piper nigrum/chemistry , Plant Extracts/chemistry , Plant Oils/chemistry , Psidium/chemistry , Thailand , Zingiberaceae/chemistrySubject(s)
Humans , Child , Asthma , Primary Prevention , Asthma/etiology , Cockroaches/drug effects , Tobacco Smoke Pollution/prevention & control , Desensitization, Immunologic/methods , Drug and Narcotic Control , Food Hypersensitivity , Fungi/drug effects , Pesticides , Tick Control , VentilationABSTRACT
El CIPEIN PF-5 es una formulación insecticida experimental, especialmente desarrollada para el control químico de los vectores del Mal de Chagas. Su composición consiste en una mezcla fumígena (90.9%w/w) y tres principios activos: lindano (4%), diclhorvos (5%) y deltametrina (0.1%). Este pote fumígeno insecticida, demostró una excelente selectividad contra insectos. En tres especies de animales vertebrados diferentes no se detectaron síntomas de intoxicación ni inhibición de la acetilcolinesterasa, después de haber sido expuestos durante 2 horas a los humos insecticidas liberados por dos potes fumígenos, en un galpón de 264 metros cúbicos. Esta concentración ambiental de principios de principios activos fue suficiente para matar al 100%de los insectos expuestos (vinchucas, moscas y cucarachas). Los residuos de insecticidas en las superficies del galpón experimental resultaron entre 0.24-0.54 *g/cm* y después de 15 días no fueron detectables. Luego de 15 min. de ventilación del ambiente, la concentración de insecticida en el aire no fue detectable (< 0.1ppm). Los residuos de insecticidas superficiales, sobre los operarios fumigadores, son menores que 0.003 *g/cm*. El residuo carbonoso de los potes fumígenos combustionados presentó sólo un resto de lindano de 0.64%. El resultado del monitoreo bioquímico y clínico, de las personas expuestas laboralmente al CIPEIN PF-5, no mostró diferencias significativas con personas no expuestas. La presente evaluación toxicológica del pote fumígeno sugiere que se trata de un formulado selectivo contra las vinchucas y otros insectos, y lo suficientemente seguro bajo condiciones de uso normales, para el hombre y otros vertebrados