Figure 1. PL402 reduces Aβ level in vitro. (A) The structure of PL402. (B) The cell viability of HEK293/APPswe cells in response to vehicle (0.1% DMSO), 0.1μM BACE inhibitor IV (BSI-IV), or the PL402 at 30μM, 100μM or 300μM for 24h measured by CellTiter-Glo Assay. N=3. (C) The total Aβ level in the culture medium of HEK293/APPswe treated with vehicle (0.1% DMSO), 0.1μM BSI-IV, or the PL402 at 30μM, 100μM or 300μM for 24h measured by ELISA. N=5. (D–E) Representative image of a western blot showing the expression of total Aβ in HEK293/APPswe (D) and its quantification normalized to control. The 1μM of BSI-IV and 10μM of Forskolin were used as the positive controls. N=3 (E). (F) The level of Aβ40 or Aβ42 in the medium of HEK293APPswe examined by ELISA after treatment with vehicle (0.1% DMSO), 0.1μM BSI-IV, or PL402 at 100μM, 300μM for 24 h. N=3. (G–H) The levels of total Aβ produced by SK-N-SH (G) (N=9) and SH-SY5Y (H) (N=6) cells by ELISA in response to vehicle (0.1% DMSO), 0.1μM BSI-IV, and the PL402 at 30μM, 100μM or 300μM for 24 h. (I) The total Aβ level in the medium of human neural stem cells (13A NSCs) measured by ELISA after treatment with vehicle (0.1% DMSO), 0.1μM BSI-IV, or the PL402 at 30μM, 100μM or 300μM for 24 hours. N=4. The Data are presented as mean ± SEM, n >3 independent experiments, *p < 0.05, **p < 0.01, ***p< 0.001 and ****p< 0.0001 compared to the control of each group, analyzed by one-way ANOVA followed by Bonferroni test.