Fig. 4

Cytotoxicity of a SH-SY5Y cells overexpressing APP695swe that were treated with FF (0, 15, 25, 50, and 100 μg/mL) for 24 h. b Effects of purified FF on Aβ42-induced cytotoxicity in SH-SY5Y cells. Cells were exposed to various concentrations of FF (25, 50, and 100 μg/mL) for 24 h. After pretreatment, cells were treated with Aβ42 (5 μM) for 24 h, and cell viability was determined by MTT assay. *P < 0.05; **P < 0.01 versus Aβ42-treated cells. ^#P < 0.01 versus Aβ42 non-treated cells. c FF treatment did not alter APP expression levels. SH-SY5Y cells overexpressing APP695swe were treated with increasing concentrations of FF (25, 50, and 100 μg/mL) for 24 h. The expression of full-length APP was determined by both RT-PCR and western blotting analysis. The levels of APP mRNA (c) and protein (d) did not significantly differ between control and FF-treated cells. Results are shown as the mean ± SEM of experiments performed in triplicate (n = 3). e Expression levels of sAPPβ and Aβ42 in SH-SY5Y-APP695swe cells treated with Leu-Asn peptide measured by western blot analysis. f FF reduced Aβ42 levels in both cell culture medium supernatants and cell lysates. SH-SY5Y cells overexpressing APP695swe were treated with increasing concentrations of FF (25, 50, and 100 μg/mL) for 24 h. Aβ42 levels were determined using Aβ40- and Aβ42-specific sandwich ELISAs. Total Aβ42 was the sum of Aβ42 in the supernatant and lysate. Results are expressed in picogram per milliliter, and all experiments were performed in triplicate (n = 3). *P < 0.05, **P < 0.01 compared with the control