The mechanism of neuroprotective effect of Viola odorata against serum/glucose deprivation-induced PC12 cell death

Abstract

<strong>Objective:</strong> Oxidative stress is associated with the pathogenesis of brain ischemia and other neurodegenerative disorders. Previous researches have shown the antioxidant activity of <em>Viola</em> <em>odorata</em> L. In this project, we studied neuro-protective and reactive oxygen species (ROS) scavenging activities of methanol (MeOH) extract and other fractions isolated from <em>V. odorata </em>in PC12 cell line in serum/glucose deprivation (SGD) condition.<br /> <strong>Materials and Methods:</strong> The PC12 neuronal cells were pretreated for 6 hr with MeOH extract and fractions of <em>V. odorata </em>(1 to 25 μg/ml) followed by 24 hr incubation under SGD condition. Cell viability was measured by Alamar Blue^®assay. The level of ROS was calculated using DCFH-DA. Also, Bax/Bcl-2 protein ratio was analyzed by western blot assay.<br /> <strong>Results:</strong> SGD condition significantly decreased cells viability (p<0.001). Pretreatment with EtOAc (12.5 and 25 µg/ml), BuOH (12, 25, 50 µg/ml) and CH₂Cl₂(1.5 µg/ml) fractions of <em>V. odorata</em> reduced SGD-induced cytotoxicity. MeOH extract could not increase the viability significantly. All four semi polar fractions (EtOAc, BuOH, CH2Cl2 and MeOH) decreased SGD-induced ROS production and changed Bax/Bcl-2 ratio.<br /> <strong>Conclusion:</strong> <em>V. odorata </em>showed promising effects against SGD condition; further mechanistic and clinical studies are warranted before application of <em>V. odorata</em> as a neuro-protective agent.