Department of Neurology, Center for Geriatric Neuroscience Research, Institute of Biomedical Science and Technology, School of Medicine, Konkuk University, Seoul, Korea.
J Clin Neurol. 2010 Sep;6(3):127-37. doi: 10.3988/jcn.2010.6.3.127. Epub 2010 Sep 30.
Recent studies have demonstrated that resveratrol (RSV) reduces the incidence of age-related macular degeneration, Alzheimer's disease (AD), and stroke, while melatonin (MEL) supplementation reduces the progression of the cognitive impairment in AD patients. The purpose of this investigation was to assess whether the co-administration of MEL and RSV exerts synergistic effects on their neuroprotective properties against β-amyloid (Aβ)-induced neuronal death.
The neuroprotective effects of co-treatment with MEL and RSV on Aβ1-42-induced cell death, was measured by MTT reduction assay. Aβ1-42 caused an increase in intracellular levels of reactive oxygen species (ROS), as assessed by H(2)-DCF-DA dye, and a reduction of total glutathione (GSH) levels and mitochondrial membrane potential, as assessed using monochlorobimane and rhodamine 123 fluorescence, respectively. Western blotting was used to investigate the intracellular signaling mechanism involved in these synergic effects.
We treated a murine HT22 hippocampal cell line with MEL or RSV alone or with both simultaneously. MEL and RSV alone significantly attenuated ROS production, mitochondrial membrane-potential disruption and the neurotoxicity induced by Aβ1-42. They also restored the Aβ1-42-induced depletion of GSH, back to within its normal range and prevented the Aβ1-42-induced activation of glycogen synthase kinase 3β (GSK3β). However, co-treatment with MEL and RSV did not exert any significant synergistic effects on either the recovery of the Aβ1-42-induced depletion of GSH or on the inhibition of Aβ1-42-induced GSK3β activation. Aβ1-42 treatment increased AMP-activated protein kinase (AMPK) activity, which is associated with subsequent neuronal death. We demonstrated that MEL and RSV treatment inhibited the phosphorylation of AMPK.
Together, our results suggest that co-administration of MEL and RSV acts as an effective treatment for AD by attenuating Aβ1-42-induced oxidative stress and the AMPK-dependent pathway.
最近的研究表明，白藜芦醇（RSV）可降低年龄相关性黄斑变性、阿尔茨海默病（AD）和中风的发病率，而褪黑素（MEL）补充可减缓 AD 患者认知障碍的进展。本研究旨在评估 MEL 和 RSV 联合应用是否对其对抗β-淀粉样蛋白（Aβ）诱导的神经元死亡的神经保护特性具有协同作用。
通过 MTT 还原测定法测量 MEL 和 RSV 联合治疗对 Aβ1-42 诱导的细胞死亡的神经保护作用。通过 H（2）-DCF-DA 染料评估 Aβ1-42 引起的细胞内活性氧（ROS）水平升高，并使用单氯代二苯并噻唑荧光染料和罗丹明 123 分别评估总谷胱甘肽（GSH）水平和线粒体膜电位的降低。使用 Western blot 分析参与这些协同作用的细胞内信号转导机制。
我们用 MEL 或 RSV 单独或同时处理鼠 HT22 海马细胞系。MEL 和 RSV 单独处理可显著减轻 Aβ1-42 诱导的 ROS 产生、线粒体膜电位破坏和神经毒性。它们还恢复了 Aβ1-42 诱导的 GSH 耗竭，使其恢复到正常范围，并阻止了 Aβ1-42 诱导的糖原合酶激酶 3β（GSK3β）的激活。然而，MEL 和 RSV 联合治疗对 Aβ1-42 诱导的 GSH 耗竭的恢复或对 Aβ1-42 诱导的 GSK3β 激活的抑制均无明显协同作用。Aβ1-42 处理增加了与随后的神经元死亡相关的 AMP 激活的蛋白激酶（AMPK）活性。我们证明 MEL 和 RSV 处理抑制了 AMPK 的磷酸化。
综上所述，我们的结果表明，MEL 和 RSV 联合应用通过减轻 Aβ1-42 诱导的氧化应激和 AMPK 依赖性途径，可作为 AD 的有效治疗方法。
