Protective effects of eriodictyol on hydrogen peroxide-induced cell death in SH-SY5Y cells

Abstract

Oxidative stress and mitochondrial dysfunction are the major causes of neuronal death in neurodegenerative disorders. Eriodictyol is a flavonoid extracted from the whole plant of Dendrobium ellipsophyllum (thai name: Ueang Thong). The antioxidant and anti-inflammatory effects of eriodictyol have been widely reported. The present study aimed to investigate the protective effect and mechanisms of eriodictyol on hydrogen peroxide (H2O2)-induced cell death in human neuroblastoma SH-SY5Y cells. The protective effect of eriodictyol on cytotoxicity induced by H2O2 was evaluated using resazurin assay. The effects on intracellular reactive oxygen species (ROS) and mitochondria membrane potential were evaluated by 2´-7’ dichlorodihydrofluorescein diacetate (DCFH-DA) assay and tetramethylrhodamine ethyl ester (TMRE) assay, respectively. The effects of eriodictyol on mitochondria-mediated apoptosis cascade were determined using western blot analysis. The results showed that pretreatment with eriodictyol (0.1, 1 and 10 µM) increased cell viability (p < 0.001), reduced intracellular ROS (p < 0.05) and increased TMRE fluorescent intensity (p < 0.05) compared to H2O2-treated alone. H2O2 induced mitochondria-mediated apoptotic signalling by decreasing Bcl-2/BAX ratio, increasing the expressions of cytochrome c, caspase-3 and cleaved caspase-3 while eriodictyol pretreatment reduced these events. In conclusion, eriodictyol can protect against H2O2-induced cytotoxicity in SH-SY5Y cells via an antioxidant effect, and consequently inhibit mitochondria-mediated apoptosis cascade.