Reduction of heavy metal (Pb2+) biosorption in zebrafish model using alginic acid purified from Ecklonia cava and two of its synthetic derivatives

Abstract

Heavy metal contamination has become a major problem that causes severe environmental and health issues due to their biosorption, bioaccumulation, and toxicity. This study was designed to evaluate heavy metal chelating abilities of alginic acid (AA) extracted from the brown seaweed Ecklonia cava and two of its derivatives prepared by the partial oxidation of the 2 degrees OH groups (OM) and partial carboxylation of the monomeric units (CM) upon reducing the heavy metal biosorption in zebrafish (Danio rerio) modal. Metal ions were quantified using ICP-OES and biopolymers were characterized by FTIR and XRD analysis. All investigated biopolymers indicated potential ability for chelating Pb2+, Cu2+, Cd2+, As3+, and Ag+. The sorption capacities were in the order of CAA>OAA>AA. All biopolymers indicated a comparatively higher chelation towards Pb2+. AA, OAA, and CM could effectively reduce Pb2+ induced toxicity and Pb2+ stress induced ROS production in zebrafish embryos. Besides, they could reduce the biosorption of Pb2+ in adult zebrafish which could lead to bioaccumulation. Since alginic acid purified from E. cava and its derivatives could be utilized as seaweed derived biopolymers to purify heavy metals contaminated water and as a dietary supplement to reduce heavy metal biosorption in organisms. (C) 2017 Elsevier B.V. All rights reserved.