Effect of Ziziphus mistol aqueous extract on Xenopus laevis embryos

GABRIELA C. SOMAINI; MARCOS REYNOSO; MANUEL J. AYBAR; NANCY VERA; CELESTE TRÍBULO

Congreso; XXXIII Reunión Anual de la Asociación de Biología de Tucumán; 2016

Asociación de Biología de Tucumán

The canonical wnt/β-catenin cell signaling pathway controls many aspects of embryonic development. Xenopus laevis embryos are an efficient experimental model to screen the role of different compounds that could be affecting this pathway. In this work an aqueous extract (AE) obtained from Ziziphus mistol fruits was used. The fitochemical analysis of EA showed the presence of high polarity compounds. With the aim of evaluating the effects of EA in Xenopus embryos they were treated with different amounts of EA from stage 3 to 10.5. Some embryos were fixed at this stage and the remaining embryos were developed until stages 26-32. Embryos at stage 10.5 showed a decrease in the expression of the dorsal lip marker gene chordin (chd). In advanced stages embryos the treatment with EA (2, 5 and 20 mg/ml) lead to an abnormal development of 14, 35 and 68% of embryos, respectively, and they showed a ventralized phenotype. On the other hand, wnt/β-catenin pathway was activated using LiCl that results in strong dorsoanteriorized phenotypes. Embryos were treated with EA until stage 6 when they were treated with LiCl for 10 min, and then were treated again with EA until stage 10.5 when EA was removed and embryos were cultured until stage 32. Axis phenotypes were scored by dorso-anterior index (DAI). A higher DAI indicates a higher rate of dorsoanteriorized embryos. Embryos treated with LiCl showed DAI=7.06 while embryos treated with LiCl and EA demonstrated a significantly DAI decrease (DAI=5.5). These results showed that Ziziphus mistol EA induces molecular and morphological phenotypes compatible with wnt/β-catenin signaling pathway inhibition and rescues the effect of this pathway activation.