Edaravone protects PC12 cells from ischemic-like injury via attenuating the damage to mitochondria

Background： Edaravone had been validated to effectively protect against ischemic injuries. In this study, we investigated the protective effect of edaravone by observing the effects on anti-apoptosis, regulation of Bcl-2/Bax protein expression and recovering from damage to mitochondria after OGD （oxygen-glucose deprivation）-reperfusion. Methods： Viability of PC 12 cells which were injured at different time of OGD injury, was quantified by measuring MTT （2-（4,5-dimethylthia-zol-2-yl）-2,5-diphenyltetrazolium bromide） staining. In addition, PC 12 cells＇ viability was also quantified after their preincubation in different concentration of edaravone for 30 min followed by （OGD）. Furthermore, apoptotic population of PC 12 cells that reinsulted from OGD-reperfusion with or without preincubation with edaravone was determined by flow cytometer analysis, electron microscope and Hoechst/Pl staining. Finally, change of Bcl-2/Bax protein expression was detected by Western blot. Results： （1） The viability of PC12 cells decreased with time （1-12 h） after OGD. We regarded the model of OGD 2 h, then replacing DMEM （Dulbecco＇s Modified Eagle＇s Medium） for another 24 h as an OGD-reperfusion in this research. Furthermore, most PC 12 cells were in the state of apoptosis after OGD-reperfusion. （2） The viability of PC 12 cells preincubated with edaravone at high concentrations （1, 0.1, 0.01 μmol/L） increased significantly with edaravone protecting PC 12 cells from apoptosis after OGD-reperfusion injury. （3） Furthermore, edaravone attenuates the damage of OGD-reperfusion on mitochondria and regulated Bcl-2/Bax protein imbalance expression after OGD-reperfusion. Conclusion： Neuroprotective effects of edaravone on ischemic or other brain injuries may be partly mediated through inhibition of Bcl-2/Bax apoptotic pathways by recovering from the damage of mitochondria.

Neurogenesis-enhancing effect of sodium ferulate and its role in repair following stress-induced neuronal damage

Ferulic acid (FA) is a ubiquitous phenolic acid of low toxicity, and sodium ferulate (SF) is its sodium salt. Our previous studies have revealed that FA shows neuroprotective effect and significant antidepressant- like effect. The aim of this study was to investigate its potential neurogenesis-enhancing effect and its role in repair following stress-induced neuronal damage. MTT assay was performed to measure the effect of SF on the growth of rat pheochromocytoma (PC12) cells;morphological and immunocytochemical meth- ods were used for assessing its differentiation-induc- ing action. Chronic mild stress (CMS) tests were per- formed to establish rat model of depression. The histopathology of animal brains was studied to ana- lyze CMS-induced morphological changes and the effect of SF on the repair of CMS-induced brain in- jury. The expressions of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) and the proliferation of neural stem cell/neural progenitor cells were assessed in the hippocampi of chronic mild stress (CMS)-induced depression-like model rats by immunohistochemistry and bromodeoxyuridine (BrdU)- incorporation assays, respectively. Our in vitro tests showed that SF promoted the proliferation of PC12 cells in the concentration range of 5 - 320 μM, and induced PC12 cells to differentiate to more mature cells with the morphological characteristics and mo- lecular marker of neuronal-like cells. In vivo tests showed that SF up-regulated the expressions of NGF and BDNF, and induced the proliferation of neural stem cell/neural progenitor cells in the hippocampi of CMS-induced depression-like model rats. This study provides evidences that SF shows neurogenesis-en- hancing effect, and its antidepressant-like effect of SF may be related directly and closely to its above-men- tioned effect.