EFFECTS OF ERICARIA BRACHYCARPA EXTRACT ON THE DEVELOPMENT OF ARBACIA LIXULA SEA URCHIN EMBRYOS

Abstract

Being macroalgae sessile organisms, they need to constantly adapt to either the abiotic and biotic components of the marine ecosystem and have developed complex adaptations to survive, including the production of bioactive molecules. The aim of this work was to evaluate the effects of an extract of the brown macroalga Ericaria brachycarpa on the development of Arbacia lixula sea urchin embryos, to evaluate the embryotoxic activity from fertilization (0 h) to the pluteus stage (72 h). The range of concentrations tested was chosen to cover a full 0-100 % abnormality curve, with doses ranging from 0 to 40 μg/mL. The extract was added at three developmental endpoints: zygote (0 hpf), gastrula (24 hpf) and pluteus (48 hpf), founding that gastrulae were the most sensitive to the extract with the lowest EC50 (5.366 μg/mL). In all treatments there was a dose-dependent effect. At low concentrations we found a significant variation in two morphometric parameters at the pluteus stage, compared to controls. The highest concentration tested (40 µg/ml) caused 100% mortality of the embryos at all embryo stages. Western Blot experiments showed the modulation of different molecular markers (HSP60, LC3, p62, CHOP and cleaved caspase-7), showing enhanced autophagy at low concentrations and apoptosis at high concentrations. The TUNEL assay confirmed high levels of fragmented DNA in 48 h exposed embryos. Further studies by means of HPLC/MS/QToF are in progress to identify which compound(s) of the E. brachycarpa extract are responsible for the embryotoxic activity.