Protective Effects of Allium senescens Extract against 6-Hydroxydopamine in Neurons

Oxidative neurodegeneration causes various neuronal diseases, including Alzheimer’s, Parkinson’s, and Huntington’s diseases. This study aimed to demonstrate the protective effect of Allium senescens leaf extracts on 6-hydroxydopamine (6-OHDA)-stressed SH-SY5Y cells, which are known to be optimal for neurotoxic research. The levels of apoptotic markers were evaluated using quantitative polymerase chain reaction (qPCR) and flow cytometry. The localization of apoptotic cells in vivo was analyzed using whole-mount immunochemistry and terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Additionally, the production of reactive oxygen species (ROS) was estimated using flow cytometry. 6-OHDA induced ROS production in neuroblasts and in vivo, but treatment with the extract protected against the 6-OHDA-induced increase in ROS levels. Under oxidative stress, the extract performs three protective functions: decreasing ROS production, preventing mitochondrial apoptosis, and protecting the central and ventral nervous systems. These results also suggest that the extract can be useful in the development of functional foods for the prevention of neural damage caused by oxidative stress.