Abstract
The purpose of the current study was to demonstrate the neuroprotective effect of protodioscin (Prot) in an in vitro model of ischemia/reperfusion (I/R) and investigate the underlying molecular mechanism. After PC12 cells were exposed to oxygen and glucose deprivation (OGD) reperfusion, PI staining by flow cytometry was used to quantify the rate of apoptosis. The levels of hypoxia-inducible factor 1-alpha (HIF-1α), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and malondialdehyde (MDA) were determined using commercially available kits. Intracellular reactive oxygen species (ROS) level was detected using the 20,70-dichlorodihy-drofluorescein diacetate (DCFH-DA) fluorescence assay. The expression levels of heat-shock proteins (HSP), PI3K, AKT, Nrf2, and miR-124 were tested by western blot or quantitative PCR. Prot significantly attenuated oxygen-glucose deprivation/reperfusion (OGD/R)-induced apoptotic death. Prot also reduced the oxidative stress as revealed by increasing the activities of SOD and GSH-Px, decreasing the levels of ROS and MDA. Moreover, mechanism investigations suggested that Prot prevented the decrease of HSP70, HSP32 (hemeoxygenase-1, HO-1), and PI3K protein expression, phosphorylation of AKT, and the accumulation of nuclear Nrf2. The level of miR-124 was decreased in PC12 cells, which was also effectively reversed by Prot treatment. Prot protected PC12 cells against OGD/R-induced injury through inhibiting oxidative stress and apoptosis, which could be associated with increasing HSP proteins expression via activating PI3K/AKT/Nrf2 pathway and miR-124 modulation.