Gláucia Maria Cavasin

Alterações ultraestruturais em larvas de Aedes aegypti submetidas ao diterpeno labdano, isolado de Copaifera reticulata (Leguminosae), e à uma fração rica em taninos de Magonia pubescens (Sapindaceae)

INTRODUCTION: Dengue is an important public health problem in many countries and its main vector Aedes aegypti, is the mosquito most adapted to urban areas. For the first time, the mechanism of action of labdane diterpenoid extracted from Copaifera reticulata and the fraction enriched of catechin tannins extracted from Magonia pubescens is demonstrated through ultrastructural alterations of Aedes aegypti larvae. METHODS: Experiments were performed using a 0.9ppm solution of diterpenoid and 3.7ppm of the fraction as the main catechin tannin of molecular mass 846Da. The compounds were obtained by thin layer chromatography and identified by nuclear magnetic resonance of hydrogen and mass spectrometry. Larvae that achieved lethargic state were collected and dissected. Next, they were contrasted with 1% uranyl acetate, dehydrated, embedded and polymerized. Ultrathin sections were made, mixed with 3% uranyl acetate and lead citrate and placed in an electron microscope. RESULTS: The main ultrastructural alterations caused by the diterpenoid and by tanins in larvae of Aedes aegypti were: cytoplasmic vacuolation, alteration of microvilli, cellular aging, cell disruption and degeneration, formation of secretion vesicles and structural changes in microvilli, irregular nuclei and displacement of cells in the basal lamina. CONCLUSIONS: The fraction containing tannins and the diterpenoid caused the death of Aedes aegypti larvae by cell destruction in the midgut.

Bisphenol-A promotes antiproliferative effects during neonatal prostate development in male and female gerbils.

The aim of this study was to evaluate the development of male and female neonatal gerbil prostate under normal conditions and exposed to bisphenol-A (BPA). Normal postnatal development of the female gerbil prostate occurs earlier than and is morphologically distinct from that occurring in males. In BPA-exposed PND8 gerbils, we have not observed evidence of alterations in the ductal branching in either gender. However, the exposure to BPA alters the immunolabeling pattern of AR, ERα, and PCNA. In males, the exposure to high dosages of BPA resulted in a decrease in the proliferative status of the developing ventral prostate. In females, both high and low dosages were sufficient to decrease the proliferation of paraurethral buds in the branching process by more than 50%. Therefore, the obtained data indicate that BPA promotes antiproliferative effects during the neonatal development of the gerbil prostate, with more sensitivity to this endocrine disruptor in females.