Figure 5. Supplementation with CPPs ameliorated Aβ pathology in N2a-APP cells. (A)The expression of APP in N2a-APP cells was estimated by western blot compared with N2a cells(n=3). (B) Quantification of the western blot results with APP normalized to GAPDH. N2a-APP cells were treated with CPPs at the indicated concentrations of 50, 100, 200 μg/ml for 24 h. (C) N2a-APP cells were assayed for cell viability, n = 3. (D) ELISA assay for Aβ1-42 levels, n = 3. (E–H) The expression of APPα, APPβ and BACE1 proteins in the N2a-APP cells was measured by Western blotting, normalized to GAPDH, n = 3. (I) Relative BACE1 activity was detected in the cells (n=6). P value significance is calculated from a one-way ANOVA or Student’s t-test. *P < 0.05, **P < 0.01 vs. cells without CPPs treatment.