Fernandes Kelly Afonsina, Ferraz Humberto Gomes, Vereau Fanny, Pinto Ernani
Department of Clinical and Toxicological Analyses, Faculty of Pharmaceutical Sciences, University of São Paulo, Av. Prof. Lineu Prestes, 580, Butantã CEP 05508-900, São Paulo, Brazil.
Department of Pharmacy, Faculty of Pharmaceutical Sciences, University of São Paulo, Av. Prof. Lineu Prestes, 580, Butantã CEP 05508-900, São Paulo, Brazil.
Pharmaceuticals (Basel). 2020 Nov 19;13(11):402. doi: 10.3390/ph13110402.
Guanitoxin (GNT) is a potent neurotoxin produced by freshwater cyanobacteria that can cause the deaths of wild and domestic animals. Through reports of animal intoxication by cyanobacteria cells that produce GNT, this study aimed to investigate the bio-accessibility of GNT in simulated solutions of the gastrointestinal content in order to understand the process of toxicosis promoted by GNT in vivo. Dissolution tests were conducted with a mixture of (Cyanobacteria; Nostocales) cultures (30%) and gastrointestinal solutions with and without proteolytic enzymes (70%) at a temperature of 37 °C and rotation at 100 rpm for 2 h. The identification of GNT was performed by LC-QqQ-MS/MS through the transitions [M + H] 253 > 58 and [M + H] 253 > 159, which showed high concentrations of GNT in simulated gastric fluid solutions (-value < 0.001) in comparison to simulated solutions of intestinal content. The gastric solution with pepsin promoted the stability of GNT (-value < 0.05) compared to the simulated solution of gastric fluid at the same pH without the enzyme. However, the results showed that GNT is also available in intestinal fluids for a period of 2 h, and solutions containing the pancreatin enzyme influenced the bio-accessibility of the toxin more compared to the intestinal medium without enzyme (-value < 0.05). Therefore, the bio-accessibility of the toxin must be considered both in the stomach and in the intestine, and may help in the diagnosis and prediction of exposure and risk in vivo through the oral ingestion of GNT-producing cyanobacteria cells.
胍毒素（GNT）是一种由淡水蓝藻产生的强效神经毒素，可导致野生动物和家畜死亡。通过对产生GNT的蓝藻细胞导致动物中毒的报告，本研究旨在调查GNT在模拟胃肠内容物溶液中的生物可及性，以了解GNT在体内引发中毒的过程。在37°C温度和100 rpm转速下旋转2小时，用（蓝藻；念珠藻目）培养物（30%）与含和不含蛋白水解酶的胃肠溶液（70%）的混合物进行溶解试验。通过LC-QqQ-MS/MS，通过[M + H] 253 > 58和[M + H] 253 > 159的跃迁对GNT进行鉴定，结果显示与模拟肠内容物溶液相比，模拟胃液溶液中GNT浓度较高（-值< 0.001）。与相同pH值不含酶的模拟胃液溶液相比，含胃蛋白酶的胃液促进了GNT的稳定性（-值< 0.05）。然而，结果表明GNT在肠液中也可存在2小时，与不含酶的肠介质相比，含胰蛋白酶的溶液对毒素生物可及性的影响更大（-值< 0.05）。因此，必须同时考虑毒素在胃和肠中的生物可及性，这可能有助于通过口服摄入产生GNT的蓝藻细胞来诊断和预测体内暴露情况及风险。
