RESUMO
Dengue is a tropical disease caused by an arbovirus transmitted by Aedes aegypti. Since no effective vaccine is available for treating dengue, the present study focused on population vector control through investigating the use of the lignan grandisin, isolated from Piper solmsianum C. DC., Piperaceae, against the larvae of A. aegypti. Grandisin caused larval (L3) mortality at LC50 150 µg/mL. Histological analysis on A. aegypti larvae treated with grandisin (LC50 50 µg/mL) showed changes in the anterior-middle midgut, with intense tissue destruction and cell disorganization.
RESUMO
Crudes extracts and fractions from seeds of Melia azedarach L. (Meliaceae) have been assayed on Musca domestica Linnaeus, 1758 (Diptera: Muscidae). Thus, the post-embryonic development of the flies was reduced and the delay from newly hatched larvae to adults had significant increase. In addition, the pupal weights were reduced and the sexual ratio altered. Toxicity to fly eggs was also observed.
Os extratos brutos e as frações obtidas das sementes de Melia azedarach L. (Meliaceae) foram testados em Musca domestica Linnaeus, 1758 (Diptera: Muscidae). Os bioensaios mostraram inibição no desenvolvimento pós-embrionário das moscas e um significativo aumento do período larva recém eclodida- adulto. Além disso, o peso pupal foi reduzido e a proporção sexual alterada. Foi observada toxicidade para os ovos das moscas.
RESUMO
A study of the phagoinhibitor and anti-moulting activities of the Brazilian Melia azedarach, collected in the state of Rio de Janeiro, Brazil, allowed the isolation of four lignanes identified as pinoresinol, bis-epi-pinoresinol, the hemicetal and the diacid. These substances are devoid of anti-moulting activity.