Piracetam Ameliorated Oxygen and Glucose Deprivation-Induced Injury in Rat Cortical Neurons Via Inhibition of Oxidative Stress, Excitatory Amino Acids Release and P53/Bax

Our previous work has demonstrated that piracetam inhibited the decrease in amino acid content induced by chronic hypoperfusion, ameliorated the dysfunction of learning and memory in a hypoperfusion rat model, down-regulated P53, and BAX protein, facilitated the synaptic plasticity, and may be helpful in the treatment of vascular dementia. To explore the precise mechanism, the present study further evaluated effects of piracetam on Oxygen and glucose deprivation (OGD)-induced neuronal damage in rat primary cortical cells. The addition of piracetam to the cultured cells 12 h before OGD for 4 h significantly reduced neuronal damage as determined by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and lactate dehydrogenase release experiments. Piracetam also lowered the levels of malondialdehyde, nitrogen monoxidum, and xanthine oxidase which was increased in the OGD cells, and enhanced the activities of superoxide dismutase and glutathione peroxidase, which were decreased in the OGD cells. We also demonstrated that piracetam could decrease glutamate and aspartate release when cortical cells were subjected to OGD. Furthermore, Western blot study demonstrated that piracetam attenuated the increased expression of P53 and BAX protein in OGD cells. These observations demonstrated that piracetam reduced OGD-induced neuronal damage by inhibiting the oxidative stress and decreasing excitatory amino acids release and lowering P53/Bax protein expression in OGD cells.

我们先前的研究已表明，吡拉西坦可抑制慢性低灌注诱导的氨基酸含量下降，改善低灌注大鼠模型的学习和记忆功能障碍，下调P53和BAX蛋白，促进突触可塑性，可能有助于治疗血管性痴呆。为了探索确切机制，本研究进一步评估了吡拉西坦对大鼠原代皮质细胞中氧糖剥夺（OGD）诱导的神经元损伤的影响。在OGD持续4小时前12小时向培养细胞中添加吡拉西坦，通过MTT（3 -（4,5 - 二甲基噻唑 - 2 - 基） - 2,5 - 二苯基四氮唑溴盐）测定和乳酸脱氢酶释放实验确定，可显著减轻神经元损伤。吡拉西坦还降低了OGD细胞中升高的丙二醛、一氧化氮和黄嘌呤氧化酶水平，并增强了OGD细胞中降低的超氧化物歧化酶和谷胱甘肽过氧化物酶活性。我们还证明，当皮质细胞受到OGD时，吡拉西坦可减少谷氨酸和天冬氨酸的释放。此外，蛋白质印迹研究表明，吡拉西坦可减弱OGD细胞中P53和BAX蛋白表达的增加。这些观察结果表明，吡拉西坦通过抑制氧化应激、减少兴奋性氨基酸释放以及降低OGD细胞中P53/Bax蛋白表达来减轻OGD诱导的神经元损伤。