Cylindrospermopsin induces neurotoxicity in tilapia fish (Oreochromis niloticus) exposed to Aphanizomenon ovalisporum

• Published in: Aquatic toxicology 2015-04, Vol.161, p.17-24
• Main Authors: Guzmán-Guillén, Remedios, Manzano, Inmaculada Lomares, Moreno, Isabel M., Ortega, Ana I. Prieto, Moyano, Rosario, Blanco, Alfonso, Cameán, Ana M.
• Format: Article
• Language: English
• Subjects: Acetylcholinesterase; Acetylcholinesterase - metabolism; Animals; Aphanizomenon - chemistry; Aphanizomenon - physiology; Aphanizomenon ovalisporum; Bacterial Toxins; Biomarkers - metabolism; Brain; Brain - drug effects; Cichlids - physiology; Cyanobacteria; Cylindrospermopsin; Enzyme Activation - drug effects; Histopathology; Lipid Peroxidation - drug effects; LPO; Oreochromis niloticus; Oxidative Stress - drug effects; Tilapia; Uracil - analogs & derivatives; Uracil - toxicity; Water Pollutants, Chemical - toxicity
• ISSN: 0166-445X; 1879-1514
• DOI: 10.1016/j.aquatox.2015.01.024

•CYN shows neurotoxicity by inhibiting AChE activity in tilapia brain.•LPO levels are increased in brain of tilapia exposed to CYN.•Histopathological changes are found in brain of tilapia exposed to CYN.•3 days of depuration recover AChE and LPO; 7 days recover the histopathology.•CYN was detected in all the brain samples analyzed by ELISA. Cylindrospermopsin (CYN) is a cytotoxic cyanotoxin produced by several species of freshwater cyanobacteria, such as Aphanizomenon ovalisporum. CYN is a tricyclic alkaloid known for its ability to inhibit both protein and glutathione synthesis, and the alteration of different oxidative stress biomarkers in mammals and vertebrates. Although the liver and kidney appear to be the main CYN targets for this toxin, it also affects other organs. In fish, there is no evidence about the neurotoxicity of CYN yet. In the present study, we aimed to study the potential neurotoxicity of CYN, based on the measure of Acetylcholinesterase (AChE) activity, lipid peroxidation (LPO) levels and histopathological studies in brain of tilapia (Oreochromis niloticus) subchronically exposed to repeated concentrations of 10μg CYN/L by immersion in an A.ovalisporum culture for 14 days. The results showed significant inhibition of AChE activity and increases in LPO levels, as well as relevant histopathological alterations in the brain of fish (O. niloticus) subchronically exposed to the toxin. Moreover, we also investigated the potential recovery of these parameters by subjecting the fish to two depuration periods (3 and 7 days) in clean uncontaminated water, showing a recovery of the biochemical parameters since 3 days of depuration, and being necessary 7 days to recover the histopathological changes. In order to support these results, CYN was detected and quantified by enzyme-linked immunosorbent assay (ELISA) in brain of all the exposed fish and the effects of the depuration periods were also observed. Based on these results, it was demonstrated for the first time the neurotoxicity of CYN and its presence in brain of tilapia fish subchronically exposed to CYN.