Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos, 2600-anexo, 90035-003, Porto Alegre, RS, Brazil.
Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Sarmento Leite, 500, 90050-170, Porto Alegre, RS, Brazil.
Behav Brain Res. 2013 Jan 1;236(1):186-193. doi: 10.1016/j.bbr.2012.08.039. Epub 2012 Sep 1.
Alzheimer's disease (AD) is the most prevalent form of dementia. Intracerebroventricular (ICV) infusion of streptozotocin (STZ) provides a relevant animal model of chronic brain dysfunction that is characterized by long-term and progressive deficits in learning, memory, and cognitive behavior, along with a permanent and ongoing cerebral energy deficit. Numerous studies on green tea epigallocatechin gallate (EGCG) demonstrate its beneficial effects on cognition and memory. As such, this study evaluated, for the first time, the effects of sub-chronic EGCG treatment in rats that were submitted to ICV infusion of STZ (3mg/kg). Male Wistar rats were divided into sham, STZ, sham+EGCG and STZ+EGCG groups. EGCG was administered at a dose of 10mg/kg/day for 4 weeks per gavage. Learning and memory was evaluated using Morris' Water Maze. Oxidative stress markers and involvement of the nitric oxide (NO) system, acetylcholinesterase activity (AChE) and glucose uptake were evaluated as well as glial parameters including S100B content and secretion and GFAP content. Our results show that EGCG was not able to modify glucose uptake and glutathione content, although cognitive deficit, S100B content and secretion, AChE activity, glutathione peroxidase activity, NO metabolites, and reactive oxygen species content were completely reversed by EGCG administration, confirming the neuroprotective potential of this compound. These findings contribute to the understanding of diseases accompanied by cognitive deficits and the STZ-model of dementia.
阿尔茨海默病(AD)是最常见的痴呆症形式。脑室内(ICV)注射链脲佐菌素(STZ)提供了一种相关的慢性大脑功能障碍动物模型,其特征是学习、记忆和认知行为长期和进行性缺陷,以及持续存在的大脑能量缺陷。大量关于绿茶表没食子儿茶素没食子酸酯(EGCG)的研究表明其对认知和记忆有有益的影响。因此,本研究首次评估了亚慢性 EGCG 治疗对接受脑室内 STZ(3mg/kg)输注的大鼠的影响。雄性 Wistar 大鼠分为假手术、STZ、假手术+EGCG 和 STZ+EGCG 组。EGCG 以 10mg/kg/天的剂量通过灌胃给药 4 周。使用 Morris 水迷宫评估学习和记忆。还评估了氧化应激标志物和一氧化氮(NO)系统的参与、乙酰胆碱酯酶活性(AChE)和葡萄糖摄取以及神经胶质参数,包括 S100B 含量和分泌以及 GFAP 含量。我们的结果表明,EGCG 不能改变葡萄糖摄取和谷胱甘肽含量,尽管认知缺陷、S100B 含量和分泌、AChE 活性、谷胱甘肽过氧化物酶活性、NO 代谢物和活性氧含量完全被 EGCG 给药逆转,证实了该化合物的神经保护潜力。这些发现有助于理解伴有认知缺陷的疾病和 STZ 痴呆模型。