Role of neuroprotective agents against oxidative radical stress in PC12 cells and N18D4 cells

Abstract

Background & Objectives : Neurodegenerative disorders are associated with apoptosis as a cause or an inducer. It is well known that H2O2 provokes apoptosis through oxidative stress. Several materials such as antioxidants (prostaglandin J2, epigallocatechin gallate, etc.) and nonselective caspase inhibitor, z-VAD-fmk, suppress cytotoxicity of H2O2 by apoptosis. Method : We investigated the effect of neuroprotective agents against oxidative radical stress in PC12 cells and N18D4 cells, which have its origin in mouse neuroblastoma x dorsal root ganglion neuron hybrid cell line. Also, we examined the role of them in the apoptotic pathway of PC12 cells and N18D4 cells. At low concentrations of H2O2 (100μM), those cells were incubated with each of them for 24hr. The assessment of cell viability using MTT assay revealed that they rescued cells from injury by oxidative stress. As following step, caspase-3, cytochrome C, and poly ADP-ribose polymerase (PARP) were investigated for caspase defendant apoptosis and glycogen synthase kinase-3 for caspase independent pathway through western. Results : We found that using each of neuroprotective agents decreased apoptosis and combination treatments of them had more antiapoptotic property. On the western studies, while the activity of caspase ?3 and the quantity of cytochrome C and PARP were diminished more than the activity of GSK-3 in the treatment of antioxidant alone, only those of caspase ?3 and PARP in z-VAD-fmk. In combination treatments of antioxidant and z-VAD-fmk, the result was something like those of antioxidant alone, but more prominent. Conclusion : In our opinion, these results imply that neuroprotective agents, above described, affect the pathway of caspase dependent apoptosis more than another pathway and higher level of apoptotic pathway above action point of cytochrome C and combination treatments are more effective in protecting apoptosis