Laboratory of Marine Toxins, Physiology and Biophysics Program, Institute of Biomedical Sciences, Faculty of Medicine, Universidad De Chile , Santiago, Chile.
Anatomy and Developmental Biology, Institute of Biomedical Sciences, Faculty of Medicine, Universidad De Chile , Santiago, Chile.
J Toxicol Environ Health A. 2020 Aug 17;83(15-16):573-588. doi: 10.1080/15287394.2020.1793046. Epub 2020 Jul 19.
Okadaic acid-group (OA-group) is a set of lipophilic toxins produced only in seawater by species of the and genera, and characterized globally by being associated with harmful algal blooms (HABs). The diarrhetic shellfish poisoning toxins okadaic acid (OA) and dinophysistoxin-1 (DTX-1) are the most prevalent toxic analogues making up the OA-group, which jeopardize environmental safety and human health through consumption of hydrobiological organisms contaminated with these toxins that produce diarrhetic shellfish poisoning (DSP) syndrome in humans. Consequently, a regulatory limit of 160 μg of OA-group/kg was established for marine resources (bivalves). The aim of this study was to investigate effects varying concentrations of 1-15 μg/ml OA or DTX-1 on toxicity, development, and oxidative damage in zebrafish larvae (). After determining the lethal concentration 50 (LC) in zebrafish larvae of 10 and 7 μg/ml (24 h) and effective concentration 50 (EC) of 8 and 6 μg/ml (24 h), different concentrations (5, 6.5, or 8 μg/ml of OA and 4, 4.5, or 6 μg/ml of DTX-1) were used to examine the effects of these toxins on oxidative damage to larvae at different time points between 24 and 120 hpf. Macroscopic evaluation during the exposure period showed alterations in zebrafish including pericardial edema, cyclopia, shortening in the anteroposterior axis, and developmental delay. The activity levels of biochemical biomarkers superoxide dismutase (SOD) and catalase (CAT) demonstrated a concentration-dependent decrease while glutathione peroxidase (GPx) and glutathione reductase (GR) were markedly elevated. In addition, increased levels of oxidative damage (malondialdehyde and carbonyl content) were detected following toxin exposure. Data demonstrate that high concentrations of OA and DTX-1produced pathological damage in the early stages of development <48 h post-fertilization (hpf) associated with oxidative damage.
冈田酸组（OA 组）是一组仅在海水中由 和 属的物种产生的亲脂性毒素，其特征是与有害藻华（HAB）有关。腹泻性贝类毒素 okadaic 酸（OA）和 dinophysistoxin-1（DTX-1）是最常见的有毒类似物，构成了 OA 组，这些毒素通过食用受这些毒素污染的水生生物，对环境安全和人类健康构成威胁，这些毒素会导致人类出现腹泻性贝类中毒（DSP）综合征。因此，为海洋资源（双壳类动物）制定了 160μgOA 组/kg 的监管限量。本研究旨在研究不同浓度（1-15μg/ml）OA 或 DTX-1 对斑马鱼幼虫（）毒性、发育和氧化损伤的影响。在确定了斑马鱼幼虫的半数致死浓度（LC）为 10 和 7μg/ml（24h）以及半数有效浓度（EC）为 8 和 6μg/ml（24h）后，采用不同浓度（5、6.5 或 8μg/ml 的 OA 和 4、4.5 或 6μg/ml 的 DTX-1），在 24-120 hpf 之间的不同时间点，检测这些毒素对幼虫氧化损伤的影响。暴露期间的宏观评估显示，斑马鱼出现了心包水肿、独眼、前后轴缩短和发育延迟等变化。生化生物标志物超氧化物歧化酶（SOD）和过氧化氢酶（CAT）的活性水平呈浓度依赖性下降，而谷胱甘肽过氧化物酶（GPx）和谷胱甘肽还原酶（GR）则显著升高。此外，在毒素暴露后，还检测到氧化损伤水平（丙二醛和羰基含量）升高。数据表明，高浓度的 OA 和 DTX-1 在受精后 48 小时（hpf）内的早期发育阶段会产生病理损伤，与氧化损伤有关。
