Neuroprotective Effects of Huperzine B and Huperzia carinata Extract Against MPP+-Induced Oxidative Stress in SH-SY5Y Cells.

Parkinson's disease (PD) is a neurodegenerative disorder associated with dopaminergic neuronal loss, mitochondrial dysfunction, and redox imbalance. Huperzine B (HupB), an alkaloid derived from Huperzia species, has demonstrated antioxidant and acetylcholinesterase-inhibitory activity; however, its effects in toxin-induced cellular models of mitochondrial oxidative injury remain incompletely characterized. This study investigated the effects of HupB and an extract derived from Huperzia carinata (E1) in 1-methyl-4-phenylpyridinium (MPP+)-induced SH-SY5Y cells. LC-MS/MS analysis identified Huperzines A, B, and caffeic acid in E1. Cells were pretreated with HupB or E1 prior to exposure to 1 mM MPP+. Cell viability, nuclear morphology, reactive oxygen species (ROS), antioxidant enzyme activity, mitochondrial membrane potential (JC-1), apoptosis-related proteins (Bax/Bcl-2), and global proteomic profiles were evaluated. HupB and E1 attenuated MPP+-induced reductions in cell viability and ROS elevation, while partially improving glutathione levels and catalase and superoxide dismutase activities. MPP+ significantly decreased mitochondrial membrane potential, whereas pretreatments did not produce significant restoration. Similarly, Bax/Bcl-2 expression showed no significant modulation despite trends toward normalization at higher concentrations. Proteomic analysis revealed altered expression of proteins associated with negative regulation of apoptosis and cellular stress responses. These findings indicate that HupB and H. carinata extract are associated with modulation of oxidative and proteostasis-related responses in an MPP+-induced undifferentiated SH-SY5Y cellular injury model, supporting further investigation in more physiologically relevant systems.