Ursolic acid inhibits autophagy-dependent neuronal cell death by reducing oxidative stress levels in an in vitro model of Parkinson's disease

Abstract Parkinson's disease (PD) is a common neurodegenerative disease in middle-aged and elderly people. The pathogenesis of PD is complicated, resulting from the comprehensive action of many factors [3-5]. In addition, increasing studies have shown that autophagy plays an important role in the development of PD [6-9]. We found that Rotenone caused ROS to build up, which led to apoptosis. However, it is still not clear whether AMPK is involved in Rotenone-induced inhibition of autophagy and apoptosis. We found that Rotenone induced a significant increase in mitochondrial oxidative stress and activated AMPK signaling, leading to a decrease in intracellular autophagy and then apoptosis. The inhibition of autophagy, oxidative stress, and apoptosis induced by Rotenone could be significantly reversed by reducing the oxidative stress level with ursolic acid. In addition, the passivation of AMPK with Ad-dnAMPKα significantly alleviate AMPK phosphorylation, autophagy inhibition, oxidative stress, and apoptosis induced by Rotenone. In conclusion, Rotenone leads to autophagosome-dependent accumulation of apoptosis by inhibiting AMPK-impaired neuronal autophagy flux. Our results highlight that inhibiting AMPK activity and oxidative stress using ursolic acid to improve autophagy levels is a promising strategy to combat Rotenone-induced neurotoxicity.