Histomorfometric Analysis of the Endochondral Ossification of the limbs of Rats submitted to Usnic Acid from Cladonia Substellata (AHTI) encapsulated in Plga-Microspheres / Análise Histomorfométrica da Ossificação Endocondral dos membros de Ratos submetidos ao Ácido Úsnico de Cladonia Substellata (AHTI) encapsulado em Microesferas de Plga

Abstract

The aim of this study was to evaluate the histology and morphometry of endochondral ossification in limbs of rats submitted to usnic acid from Cladonia substellata (AHTI) encapsulated in PLGAmicrospheres. It was used 12 pregnant Wistar rats that were randomly distributed in the control groups (n = 6), which received 1.0 mL of saline solution; and treated (n = 6), that received 25 mg/kg/day of encapsulated usnic acid in PLGA microspheres by oral administration. It was analyzed six fetuses from each rat under study. At the 20th day of gestation were euthanized the females and their fetuses removed for histomorphometric analysis of the anterior and posterior limbs. The results showed the epiphyseal discs of the animals with cell alterations, as in the morphology and numbers of chondrocytes. It also showed a decrease in the amount of collagen type I collagen in bone tissue. However, this study showed low toxicity of the encapsulated usnic acid on bone development, when compared to its conventional dosage form. In this way, the toxicity of usnic acid can be reduced by encapsulation in PLGA-microspheres.