Phyllostachys nigra Variety Henosis, a Domestic Bamboo Species, Protects PC12 Cells from Oxidative Stress-mediated Cell Injury through Nrf2 Activation

Oxidative stress is induced by an imbalanced redox status, and the brain is one of the physical organs particularly weakly to reactive oxygen species (ROS) because of its requirement of high oxygen and abundance of peroxidation-sensitive lipid cells. Many studies have reported that oxidative stress plays a crucial role in the cause of neurodegenerative disorders such as Alzheimer’s and Parkinson’s disease. Antioxidant therapy has thus been proposed for the prophylaxis and treatment of neurodegenerative diseases. Previously, we reported the pharmacological efficacy of bamboo stems, including hepato-protection and anti-melanogenesis. Albeit, pharmacological efficacies of bamboo stems in neurodegenerative diseases have been unveiled. Therefore, we currently investigated the neuroprotective effect of PN3 (acetate fraction of the 80% ethylalcohol extract of domestic bamboo stems of Phyllostachys nigra variety henonis) in PC12 cells, a rat pheochromocytoma cell line, against oxidative stress-mediated cell injury. Results of this study demonstrated that PN3 could activate nuclear factor erythroid 2-related factor 2 (Nrf2) to counteract the oxidative injuries of PC12 cells. PN3 facilitates the phosphorylation and nuclear translocation of Nrf2 through the AKT/ERK/P38 pathway. Nrf2 activation by PN3 induced Nrf2 downstream antioxidant enzymes, such as heme oxygenase 1, glutamate-cysteine ligase, and NADPH quinone oxidoreductase 1. Moreover, PN3 prevented ROS generation and cell death induced by tert-butyl hydroperoxide. Furthermore, human amyloid beta peptide aggregation was antagonized by PN3 in vitro. Collectively, our results indicate that PN3 provides neuroprotection via Nrf2 activation in PC12 cells.