Asghari Ali Akbar, Hosseini Mahmoud, Bafadam Soleyman, Rakhshandeh Hasan, Farazandeh Maryam, Mahmoudabady Maryam
Department of Physiology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
Division of Neurocognitive Sciences, Psychiatry and Behavioral Sciences Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
Avicenna J Phytomed. 2022 Mar-Apr;12(2):163-174. doi: 10.22038/AJP.2021.18989.
The aim of the present study was to assess olive leaf extract (OLE) effects on learning and memory deficits in a model of diabetes induced by streptozotocin (STZ) in rats.
The rats were divided as: (1) control rats, (2) diabetic rats, and (3-6) diabetic rats treated by 100, 200, and 400 mg/kg of OLE or metformin. Using the passive avoidance test (PA), we investigated fear learning and memory behaviors. In cortical and hippocampus tissues, total levels of malondialdehyde (MDA) and thiol were measured along with the activity of catalase (CAT) and superoxide dismutase (SOD).
Learning and memory behavior impairment were significantly developed in diabetic rats as shown by the impairment of the PA task compared to the control group (p<0.001). In addition, elevated levels of MDA and reduced overall concentrations of thiol, CAT and SOD activity were obvious in diabetic rats' cortex and hippocampus tissues (p<0.01-p<0.001). Meanwhile, OLE in a dose-dependent manner, improved memory deficit and cognitive performance that was attributed to a reduction of lipid peroxidation and elevation of total thiol concentration, and CAT and SOD activity levels in the brain tissues (p<0.05-p<0.001).
OLE could be effective in improving cognitive impairment in STZ-induced diabetes by oxidative stress depression.
本研究旨在评估橄榄叶提取物（OLE）对链脲佐菌素（STZ）诱导的大鼠糖尿病模型中学习和记忆缺陷的影响。
将大鼠分为：（1）对照大鼠，（2）糖尿病大鼠，以及（3 - 6）用100、200和400 mg/kg的OLE或二甲双胍治疗的糖尿病大鼠。使用被动回避试验（PA），我们研究了恐惧学习和记忆行为。在皮质和海马组织中，测量了丙二醛（MDA）和硫醇的总水平以及过氧化氢酶（CAT）和超氧化物歧化酶（SOD）的活性。
与对照组相比，糖尿病大鼠的PA任务受损，表明学习和记忆行为受损显著（p<0.001）。此外，糖尿病大鼠皮质和海马组织中MDA水平升高，硫醇、CAT和SOD活性的总体浓度降低明显（p<0.01 - p<0.001）。同时，OLE以剂量依赖的方式改善了记忆缺陷和认知表现，这归因于脂质过氧化的减少以及脑组织中总硫醇浓度、CAT和SOD活性水平的升高（p<0.05 - p<0.001）。
OLE可能通过减轻氧化应激有效改善STZ诱导的糖尿病中的认知障碍。
