The Protective Effect Of Trihexyphenidyl On The Beta-amyloid Peptide_25-35-induced Cytotoxicity In PC12 Cells

Objective:To investigate the the protective effect of Trihexyphenidyl on the beta-amyloid peptide _25-35-induced cytotoxicity in rat pheochromocytoma cells (PC12) cells.Methods:Different dose of Aβ_25-35 was used to induce the cytotoxicity in PC12 cells in order to optimize dose by MTT assay.The enzyme activity of superoxide dismutase(SOD),glutathione peroxidase(GSH-PX) and the lipid peroxidation products malondialdehyde(MDA) in the cells were observed.DNA-binding dye Acridine Orange(AO) was used to determine the morphological characteristic of apoptotic cells.Mitochondrial membrane potential in PC12 cells were monitored by fluorospectrophotometer combining with Rh123.Fura-2/AM was employed to detect intracellular Ca²⁺ concentration([Ca²⁺]i) as a cell permeable fluorescent probe.Results:1.After treatment with 10μM preaggregated Aβ_25-35 in PC12 cells for 48 hours,the cell viability decreased markedly,while THY at the different concentration(0.01μM,0.1μM,1μM) could elevate the cell viability obviously. 2.The results suggest that Aβ_25-35 decreased SOD and GSH-PX activity,in contrast, Aβ_25-35 increased MDA and ROS.THY significantly decreased ROS and MDA, increased SOD and GSH-PX activity in PC12 cells.3.After the treatment with 10μM Aβ_25-35,the mitochondrial membrane potential significantly decreased while intracellular[Ca²⁺]i increased,and microscopic observation showed that PC12 cells exhibited morphological alterations such as cell shrinkage and membrane blabbing,the typical characteristics of apoptotic cell death,which was reduced with co-treatment of THY.Conclusions:1.10μM preaggregated Aβ_25-35 could induce toxicity,oxidative damage and apoptosis in addition to overload of Ca²⁺ in PC12 cells,which result in the cell death ultimately.2.The study shows that THY at the different concentration has a protective effects against Aβ_25-35-induced cytotoxicity and apoptosis in PC12 cells,which may represent the cellular mechanisms including scavenging ROS,increasing SOD and GSH-PX activity,inhibiting the cell apoptosis and overload of Ca²⁺ in PC12 cells.THY may also represent a potential treatment strategy for AD.