Chrysophanic acid

Chrysophanic acid preferentially blocked proliferation in SNU-C5 cells but not in other cell lines (HT7, HT29, KM12C, SW480, HCT116 and SNU-C4) with low levels of EGFR expression. Chrysophanic acid treatment in SNU-C5 cells inhibited EGF-induced phosphorylation of EGFR and suppressed activation of downstream signaling molecules, such as AKT, extracellular signal-regulated kinase (ERK) and the mammalian target of rapamycin (mTOR)/ribosomal protein S6 kinase (p70S6K). Chrysophanic acid (80 and 120 Âm) significantly blocked cell proliferation when combined with the mTOR inhibitor, rapamycin. These findings offer the first evidence of anticancer activity for chrysophanic acid via EGFR/mTOR mediated signaling transduction pathway.