Protective effects of betanin, a novel acetylcholinesterase inhibitor, against HO-induced apoptosis in PC12 cells.

Background: Dysfunction of the cholinergic system and increased oxidative stress have a crucial role in cognitive disorders including Alzheimer's disease (AD). Here, we have investigated the protective effects of betanin, a novel acetylcholinesterase (AChE) inhibitor, on hydrogen peroxide (HO)-induced cell death in PC12 cells.

Methods And Results: The protective effects were assessed by measuring cell viability, the amount of reactive oxygen species (ROS) production, AChE activity, cell damage, and apoptosis using resazurin, 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA), Ellman method, lactate dehydrogenase (LDH) release, propidium iodide (PI) staining and flow cytometry, and Western blot analysis. HO (150 µM) resulted in cell viability reduction and apoptosis induction while, pretreatment with the betanin (10, 20, and 50 μM) and N-Acetyl-L-cysteine (NAC) (2.5 and 5 mM) significantly increased the viability (P < 0.05, P < 0.01 and P < 0.001) and at 5-50 μM betanin decreased ROS amount (P < 0.05, P < 0.01 and P < 0.001). Whereas, pretreatment with the betanin (10, 20, and 50 μM) decreased AChE activity (P < 0.001), also at 20 and 50 μM betanin reduced the release of LDH (P < 0.001), and at 10-50 μM decreased the percentage of apoptotic cells (P < 0.001). Apoptosis biomarkers such as cleaved poly (ADP-ribose) polymerase (PARP) (P < 0.01 and P < 0.001) and cytochrome c (P < 0.05 and P < 0.001) were attenuated after pretreatment of PC12 cells with betanin at 10-20 μM and 10-50 μM respectively. Indeed, survivin (P < 0.001) increased after pretreatment of cells with betanin at 10-20 μM.

Conclusions: Overall, betanin may use the potential to delay or prevent cell death caused by AD through decreasing the activity of AChE as well as attenuating the expression of proteins involved in the apoptosis pathway.