Medicated rat serum containing Gengnianchun decoction reduces apoptosis of pheochromocytoma cells insulted by amyloid beta protein.

Objective: To investigate the effects of medicated rat serum containing Gengnianchun (GNC) decoction and its protection to pheochromocytoma cells (PC12 cells) from amyloid beta (Abeta)(25-35)-insulted apoptosis and to find the possible mechanism.

Methods: Medicated rat serum was prepared by administering ovariectomized Sprague-Dawley (SD) rats with GNC decoction. The effects of medicated rat serum on viability of PC12 cells were evaluated by cell counting kit-8 (CCK-8) assay. The PC12 cells were cultured with different doses of Abeta(25-35) to induce a model of Alzheimer's disease in vitro. Then, the protective effects of medicated rat serum on Abeta(25-35)-insulted PC12 cells were evaluated by using CCK-8 assay to detect the cell viability, using Annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI) flow cytometry to detect cell apoptosis rate and using Western blotting assay to analyze the expressions of Bcl-2, Bax and active caspase-3 proteins.

Results: PC12 cells cultured with 20% medicated rat serum containing GNC decoction for 24 h or 48 h had higher viability than those cultured with normal culture medium (P<0.05). After 24- or 48-hour treatment of different concentrations of Abeta(25-35), cell viabilities were all decreased as compared with normal medium (P<0.05). Cells underwent apoptosis, which showed the neurotoxicity of Abeta(25-35). The cell apoptosis induced by Abeta 25-35 was significantly decreased in PC12 cells which were pretreated with 20% medicated rat serum or nerve growth factor (NGF) according to CCK-8 assay and Annexin V-FITC/PI flow cytometry (P<0.05). The ratio of Bax expression to Bcl-2 expression and the expression of active caspase-3 were decreased in the cells treated with medicated serum or NGF as compared with the cells cultured with Abeta(25-35) only.

Conclusion: The GNC-medicated rat serum at concentration of 20% can promote viability of Abeta(25-35)-insulted PC12 cells and decrease the cell apoptosis by regulating the expressions of Bcl-2, Bax and active caspase 3.