Rizzetti Danize Aparecida, Altermann Caroline Dalla Colletta, Martinez Caroline Silveira, Peçanha Franck Maciel, Vassallo Dalton Valentim, Uranga-Ocio José Antonio, Castro Marta Miguel, Wiggers Giulia Alessandra, Mello-Carpes Pâmela Billig
Cardiovascular Physiology Laboratory, Universidade Federal do Pampa, BR 472, Km 592, Uruguaiana, Rio Grande do Sul, Brazil.
Stress, Memory and Behavior Laboratory, Universidade Federal do Pampa, BR 472, Km 592, Uruguaiana, Rio Grande do Sul, Brazil.
Neurochem Int. 2016 Dec;101:30-37. doi: 10.1016/j.neuint.2016.10.002. Epub 2016 Oct 11.
The study aimed to investigate whether the Egg White Hydrolysate (EWH) is able to prevent the recognition memory disorders associated with long-term Hg exposure in rats. For this, male Wistar rats were treated for 60 days with: a) Untreated: saline solution (i.m.); b) Hydrolysate: EWH (1 g/kg/day, gavage); c) Mercury: HgCl (1st dose 4.6 μg/kg, subsequent doses 0.07 μg/kg/day, i.m.); d) Hydrolysate-Mercury. Object recognition memory test was performed to verify Short (STM) and Long-Term Memory (LTM) and Open Field, Plus Maze and Tail Flick tests were performed as control for behavioural experiments. Reactive Oxygen Species (ROS) in the hippocampus were determined by the dichlorofluorescein diacetate (DCFH-DA) method, malondialdehyde (MDA) levels by TBARS, antioxidant power by FRAP assay and total Hg concentration by atomic fluorescence spectrometry. We confirm that the STM and LTM were impaired in adult rats exposed to Hg at low concentrations, which may be related to the increased metal deposition, ROS production and subsequent oxidative damage in the hippocampus. In addition, we demonstrated for the first time that EWH treatment is able to prevent memory impairment induced by Hg exposure, reducing Hg content and ROS production in the hippocampus. In conclusion, EWH prevents memory impairments induced by chronic exposure to low doses of Hg. These findings may represent a good public health strategy since they indicate that EWH is a promising candidate as a new natural therapy for heavy metal intoxication.
该研究旨在调查蛋清水解物（EWH）是否能够预防与大鼠长期汞暴露相关的认知记忆障碍。为此，将雄性Wistar大鼠用以下方式处理60天：a）未处理组：生理盐水（肌肉注射）；b）水解物组：EWH（1克/千克/天，灌胃）；c）汞组：HgCl（首剂4.6微克/千克，后续剂量0.07微克/千克/天，肌肉注射）；d）水解物-汞组。进行物体识别记忆测试以验证短期（STM）和长期记忆（LTM），并进行旷场试验、加迷宫试验和甩尾试验作为行为实验的对照。采用二氯荧光素二乙酸酯（DCFH-DA）法测定海马体中的活性氧（ROS），采用硫代巴比妥酸反应物（TBARS）法测定丙二醛（MDA）水平，采用铁离子还原抗氧化能力（FRAP）测定法测定抗氧化能力，并通过原子荧光光谱法测定总汞浓度。我们证实，低浓度汞暴露的成年大鼠的STM和LTM受损，这可能与金属沉积增加、ROS产生以及随后海马体中的氧化损伤有关。此外，我们首次证明EWH处理能够预防汞暴露引起的记忆损伤，降低海马体中的汞含量和ROS产生。总之，EWH可预防低剂量汞慢性暴露引起的记忆损伤。这些发现可能代表了一项良好的公共卫生策略，因为它们表明EWH作为一种治疗重金属中毒的新型天然疗法具有很大潜力。
