Effects of fraction 1 CI RJP on the mRNA levels of Aβ metabolism related genes. In order toinvestigate how 1 CI RJP down-regulates extracellular Aβ1-40 and Aβ1-42 accumulation in N2a/APP cells, weperformed real-time PCR (qPCR) to determine the change of mRNA levels for Aβ metabolism related genes.We treated the cells with 9 μg/ml 1 C1 RJP for 24 or 12 hours after the cells were cultured for 24 hours. Severalgenes related to Aβ metabolism were examined, including APP, BACE1, Presenilin 1 (PS1), Presenilin 2 (PS2),Insulin-degrading enzyme (IDE), apolipoprotein E (APOE), low density lipoprotein related receptor (LRP1),and low density lipoprotein receptor (LDLR). The mRNA levels of most genes analyzed, including APP, PS1, PS2,IDE, APOE, LRP1 and LDLR, were remain unchanged by the treatment of 1 C1 RJP compared with N2a/APPgroup at 24-hour time point (Fig. 5A,B). However, with a 12-hour 1 C1 RJP treatment, gene expression of IDE andLRP1 was significantly up-regulated, whereas expression of APOE was down-regulated; the expression of othergenes was still not significantly changed (Fig. 5C,D). Furthermore, we investigated BACE1 expression at 3 hours,6 hours, 12 hours and 24 hours’ treatment with 9 μg/ml 1C1 RJP, results indicated that BACE1 mRNA level wassignificantly down-regulated after cells were treated for 6 hours (Fig. 5E).