Ramos Márcio Viana, Bandeira Glaís de Paiva, de Freitas Cléverson Diniz Teixeira, Nogueira Nádia Accioly Pinto, Alencar Nylane Maria Nunes, de Sousa Petrônio Augusto Simão, Carvalho Ana Fontenele Urano
Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Campus do Pici, 60451-970 Fortaleza, CE, Brasil.
Mem Inst Oswaldo Cruz. 2006 Aug;101(5):503-10. doi: 10.1590/s0074-02762006000500004.
Calotropis procera R. Br. (Asclepiadaceae) is a well-known medicinal plant with leaves, roots, and bark being exploited by popular medicine to fight many human and animal diseases. This work deals with the fractionation of the crude latex produced by the green parts of the plant and aims to evaluate its toxic effects upon egg hatching and larval development of Aedes aegypti. The whole latex was shown to cause 100% mortality of 3rd instars within 5 min. It was fractionated into water-soluble dialyzable (DF) and non-dialyzable (NDF) rubber-free materials. Both fractions were partially effective to prevent egg hatching and most of individuals growing under experimental conditions died before reaching 2nd instars or stayed in 1st instars. Besides, the fractions were very toxic to 3rd instars causing 100% mortality within 24 h. When both fractions were submitted to heat-treatment the toxic effects were diminished considerably suggesting low thermostability of the toxic compounds. Polyacrylamide gel electrophoresis of both fractions and their newly fractionated peaks obtained through ion exchange chromatography or desalting attested the presence of proteins in both materials. When submitted to protease digestion prior to larvicidal assays NDF lost most of its toxicity but DF was still strongly active. It may be possible that the highly toxic effects of the whole latex from C. procera upon egg hatching and larvae development should be at least in part due to its protein content found in NDE However the toxicity seems also to involve non protein molecules present in DF.
牛角瓜（Calotropis procera R. Br.，萝摩科）是一种著名的药用植物，其叶、根和树皮被传统医学用于治疗多种人类和动物疾病。这项工作涉及对该植物绿色部分产生的粗乳胶进行分离，并旨在评估其对埃及伊蚊卵孵化和幼虫发育的毒性作用。结果表明，整个乳胶在5分钟内可导致三龄幼虫100%死亡。它被分离成水溶性可透析部分（DF）和不可透析部分（NDF）的无橡胶物质。这两个部分在预防卵孵化方面都有一定效果，并且在实验条件下生长的大多数个体在达到二龄之前死亡或停留在一龄。此外，这些部分对三龄幼虫毒性很大，在24小时内导致100%死亡。当对这两个部分进行热处理时，毒性作用显著降低，表明有毒化合物的热稳定性较低。对这两个部分及其通过离子交换色谱或脱盐获得的新分离峰进行聚丙烯酰胺凝胶电泳，证明这两种物质中都存在蛋白质。在进行杀幼虫试验之前，NDF经蛋白酶消化后大部分毒性丧失，但DF仍然具有很强的活性。牛角瓜全乳胶对卵孵化和幼虫发育的高毒性作用可能至少部分归因于在NDF中发现的蛋白质含量。然而，毒性似乎也涉及DF中存在的非蛋白质分子。
