Abstract: This study focuses on the protective role of  Polygonum multiflorum glycosides (PMG) on hydrogen peroxide (H₂O₂)-induced neuronal injury and the involvement of brain-derived neurotrophic factor/tyrosine kinase receptor B (BDNF/TrkB) signaling pathway.Oxidative stress injury model of neonatal rat hippocampal neurons was used.The results showed that the high concentration of H₂O₂ is associated with the lower the cell viability with MTT assay and 200 μmol/L H₂O₂,resulting in cell viability between 40% and 50%,was chosen for inducing oxidative stress.PMG pretreatment group (200 μmol/L) inhibited H₂O₂-induced neuronal damage comparing to model group (P<0.001).TUNEL and β-tubulin III fluorescence staining showed PMG protected H₂O₂ induced damage of neuronal cells,the apoptosis rate (P<0.001),and the damaged cytoskeleton morphology.Comparing with the PMG+H₂O₂ pretreatment group,inclusion of K252a,a BDNF/TrkB signal transduction pathway blocker,decreased the neuronal survival rate (P<0.01) and maintained an abnormal state of cytoskeletal morphology.Finally,we found that PMG pretreatment restored H₂O₂ induced lower expression level of BDNF and P-TrkB and blocking BDNF/TrkB signaling with K252a inhibit the PMG effect on BDNF and P-TrkB expression level.In summary,PMG has a protective effect on H₂O₂-induced oxidative stress in neonatal rat hippocampal neurons,potentially through activation of BDNF/TrkB signal transduction pathway to maintain normal morphology of neuronal skeleton.

Key words: Polygonum multiflorum glycosides, hydrogen peroxide, hippocampal neurons, oxidative stress, BDNF/TrkB signaling pathway