Protective effects of astaxanthin from Haematococcus pluvialis on the survival and oxidative stress of zebrafish embryos induced by microcystin-LR

This study evaluated the individual effects of microcystin-LR (MC-LR) with different concentrations (0, 10, 20, 30, 40 and 50 μg L−1) and the combined influences with astaxanthin (10 and 100 μg L−1) from Haematococcus pluvialis on the survival and oxidative stress of zebrafish embryos. Results showed that the reactive oxygen species (ROS), malondialdehyde (MDA), mortality and deformity rate were increased in the presence of MC-LR accompanied with the reduction of the glutathione peroxidase (GSH), superoxide dismutase (SOD), the total antioxidant capacity (T-AOC) and hatching rate of the zebrafish embryo. The higher the MC-LR concentration was, the stronger the developmental and oxidative stress response (p < 0.05). This study confirmed that the supplementation of astaxanthin could significantly alleviate the toxic effects of MC-LR on zebrafish embryos. The mortality and deformity rates decreased significantly in the combined exposure group compared with the only MC-LR exposure group, and the decreasing rates were positively correlated with the astaxanthin concentration. Astaxanthin could also significantly improve the oxidative stress response and damage caused by MC-LR. The ROS and MDA contents of juvenile fish decreased, whereas GSH, SOD and T-AOC increased significantly with astaxanthin supplementation. Therefore, astaxanthin might be a suitable diet supplement against the MC-LR contamination of pond aquaculture.