| |
| BACKGROUND: Formaldehyde-induced neurotoxicity is implicated in the pathology of Alzheimer's disease. Icariin, a flavonoid found in Chinese herbal medicine Epimedium, exhibits neuroprotective activity; however, whether Icariin antagonizes formaldehyde-induced nerve injury is unclear. AIMS: To investigate the neuroprotective effects of Icariin on formaldehyde-treated SH-SY5Y cells and the possible mechanisms involved. METHODS: SH-SY5Y cells were divided into control group, formaldehyde treatment group, and Icariin treatment group. Cell viability, apoptosis, and morphological changes were determined by CCK8, flow cytometry, and confocal microscopy, respectively. The phosphorylation of protein tau was examined by Western blot. RESULTS: Formaldehyde showed a half lethal dose (LD50) of 0.3 mM in SH-SY5Y cells. Icariin (1 - 10 μM) prevented formaldehyde-induced cell death in SH-SY5Y cells in a dose-dependent manner, with the optimal effect observed at 5 μM. Examination of cell morphology by confocal microscopy demonstrated that 5 μM ICA significantly attenuated formaldehyde-induced cell injury. Additionally, Icariin inhibited formaldehyde-induced cell apoptosis in SH-SY5Y cells. Results from western blot analysis showed that Icariin suppressed formaldehyde-induced tau phosphorylation at Thr181 and Ser396, while having no effect on the total tau protein level. Furthermore, Icariin reduced Tyr216 phosphorylation and increased Ser9 phosphorylation of the tau kinase GSK-3β. CONCLUTION: Icariin protects SH-SY5Y cells from formaldehyde-induced injury possibly through inhibition of GSK-3β-mediated tau phosphorylation.????? |
|
| Keywords:Icariin; formaldehyde; phosphorylation of protein tau; GSK-3β; neuroprotection |
|
