Protective Effect of Psoralea corylifolia L. Seed Extract against Palmitate-Induced Neuronal Apoptosis in PC12 Cells

Figure 5

Effect of IsoPSO on PA-induced apoptosis, ROS production, and autophagy in PC12 cells. (a) PC12 cells were incubated in media containing isopsoralen (IsoPSO) (0.1–5 μg/ml) for 24 h (left side). The cells were pretreated with 0.1–5 μg/ml IsoPSO for 6 h, followed by exposure to 0.4 mM PA for 24 h (right side). Cell viability was measured by MTT assay. (b) The cells were pretreated with 1 μg/ml IsoPSO for 6 h, followed by exposure to 0.4 mM PA for 24 h. The cells were costained with FITC-Annexin V/PI and analyzed by flow cytometry to determine the population of cells in the early stage of apoptosis. Graph shows quantitative data for the percentage of early apoptotic cells (the lower right quadrant). (c) Cells were pretreated with 1 μg/ml IsoPSO for 2 h, followed by exposure to 0.4 mM PA for 3 h. The cells were stained with 10 μM H₂-DCFDA, and intracellular ROS generation was determined by DCF. H₂O₂ (200 μM) was used as a positive control. (d) The cells were pretreated with 1 μg/ml IsoPSO for 6 h, followed by exposure to 0.4 mM PA for 24 h. Total RNA was extracted from PC12 cells and the mRNA expression levels of beclin-1 and p62 were analyzed by quantitative RT-PCR. The mRNA levels were normalized with those of cyclophilin. (e) Protein levels of beclin-1 and p62 were analyzed by western blot analyses. Actin was used as the internal control. The results shown represent the mean ± SEM from triplicate experiments. and as compared with control. and as compared with PA.

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