Neuroprotective Properties of Panax notoginseng Saponins via Preventing Oxidative Stress Injury in SAMP8 Mice

Inhibiting oxidative damage in early stage of Alzheimer's disease (AD) is considered as a strategy for AD treatment. Our previous study has shown that Panax notoginseng saponins (PNS) have an antiaging action by increasing the levels of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-PX) in the serum of aged rats. In this study, we aimed to investigate the effects of PNS on antioxidant enzymes and uncoupling proteins (UCPs) involved in oxidative stress in AD mice. The results showed that PNS prevented neuronal loss in hippocampal CA1 region and alleviated pathomorphological change of neurons in CA1 region. Moreover, PNS inhibited the production of 8-hydroxydeoxyguanosine (8-OHdG), enhanced the expressions and activities of SOD, CAT, and GSH-PX, and improved the mRNA and protein levels of UCP4 and UCP5 in the brains of SAMP8 mice. Together, our study shows that PNS has the ability to protect neurons in AD brain from oxidative stress damage through attenuating the production of 8-OHdG, enhancing the activities of antioxidant enzymes and the expressions levels of UCP4 and UCP5. Accordingly, PNS may be a promising agent for AD treatment.