Protective Effect of Trehalose Against H2O2-induced Cytotoxicity and Oxidative Stress in PC-12 Cell Line and the Role of Heat Shock Protein-27

Background: Oxidative stress has been shown to be an important factor, which plays a significant role in the pathogenesis of neurodegenerative disorders. Heat Shock Protein-27 (HSP-27) has been implicated in antioxidant responses against oxidative stress. Trehalose is a natural disaccharide widely used in a variety of food products with demonstrated protective effects against several neurodegenerative diseases. This study investigated the effects of trehalose on antioxidant responses, and the gene expressions for HSP-27 and caspase-3 against hydrogen peroxide (H2O2) induced oxidative injury in PC-12 cell line.  Methods: The PC-12 cells were treated with various concentrations of H2O2 and trehalose for 24hr. The cell viability was assessed, using MTT and Lactate Dehydrogenase (LDH) release assays. Moreover, the activity of Catalase (CAT) and Glutathione Peroxidase (GPx) enzymes, and the Malondialdehyde (MDA) levels were determined. In addition, the levels of HSP-27 and caspase-3 gene expressions were measured.  Results: The results indicated that the pretreatment with trehalose increased cell survival against the H2O2-induced oxidative injury. Furthermore, trehalose elevated the CAT and GPx activities and reduced MDA levels compared to that of control group (P˂0.05). Moreover, trehalose upregulated the HSP-27 gene expression, while reducing the expression of caspase-3 gene compared to that of the untreated cells (P˂0.05). All of these biochemical changes were found to be dose-dependent for trehalose.  Conclusion: Based on the study findings, trehalose had the capacity to attenuate the oxidative stress and cell injury. Therefore, trehalose may be suggested as a therapeutic agent to treat neurodegenerative disorders caused by oxidative stress damages.