Programa de Pós-Graduação em Ecologia e Conservação, Universidade Federal do Paraná, Setor de Ciências Biológicas CEP 81531-990, Caixa Postal 19031, CEP 81531-970, Curitiba-Pr, Brazil.
Toxicon. 2011 Jan;57(1):141-7. doi: 10.1016/j.toxicon.2010.10.015. Epub 2010 Nov 10.
Cyanobacterial waterblooms, such as the saxitoxin (STX) producer Cylindrospermopsis raciborskii, have been a worldwide concern in environmental health. However, the bioaccumulation of this neurotoxin in the trophic chain is not completely known. The aim of the present work was to evaluate STX bioaccumulation through chemical analyses and the toxic and trophic effects using biomarkers in the tropical freshwater fish Hoplias malabaricus. They were fed once every five days with Astyanax sp. before being subjected to intraperitoneal inoculation with STX extract (0.08 μg/100 g) obtained by lysis of toxic C. raciborskii strain (T3). After 20 days the brain was collected for acetylcholinesterase (AChE), superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), glutathione peroxidase (GPx), glutathione (GSH), lipoperoxidation (LPO), protein carbonylation (PCO), and comet assay analysis. The muscle was collected for STX chemical analysis. The activities of SOD and concentrations of PCO and LPO increased. The CAT, GST, and GPx activities decreased. Genotoxicity was observed in the experimental group. STX was not detected in muscle samples. Thus, an oxidative stress was observed in the brain, leading to the damage of lipids, proteins, and DNA. The mechanism of action of the neurotoxin in this subchronic exposure suggests an apoptotic cellular process.
蓝藻水华，如产生石房蛤毒素（STX）的念珠藻属（Cylindrospermopsis raciborskii），一直是全球环境健康关注的问题。然而，这种神经毒素在食物链中的生物累积情况尚不完全清楚。本研究旨在通过化学分析和使用生物标志物评估热带淡水鱼小口脂鲤（Hoplias malabaricus）中的 STX 生物累积，该鱼经口投喂过每隔五天投喂一次的棘腹鱼属（Astyanax sp.），然后用通过毒性念珠藻属（T3）细胞裂解获得的石房蛤毒素提取物（0.08μg/100g）进行腹腔内接种。20 天后，采集大脑进行乙酰胆碱酯酶（AChE）、超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、谷胱甘肽 S-转移酶（GST）、谷胱甘肽过氧化物酶（GPx）、谷胱甘肽（GSH）、脂质过氧化（LPO）、蛋白羰基化（PCO）和彗星试验分析。采集肌肉进行 STX 化学分析。SOD 活性和 PCO 和 LPO 的浓度增加。CAT、GST 和 GPx 活性降低。实验组观察到遗传毒性。肌肉样本未检测到 STX。因此，大脑中观察到氧化应激，导致脂质、蛋白质和 DNA 损伤。神经毒素在亚慢性暴露中的作用机制表明存在细胞凋亡过程。
