Figure 4. Supplementation with CPPs mitigated Aβ pathology in APP transfected HEK293 cells. (A) Western blotting was performed to detect the expression of APP in HEK293 cells transfected with APP plasmid or vector (n=3). (B) Quantification of the western blot results with APP normalized to GAPDH. (C) HEK293 cells were transfected with APP plasmid (293-APP cells) followed by CPPs supplementation at the indicated concentrations of 50, 100, 200 μg/ml for 24 h. 293-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 293-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.