In Vitro activity: Chrysophanic acid (Chrysophanol) is a EGFR/mTOR pathway inhibitor. Chrysophanic acid (Chrysophanol) is a natural anthraquinone, has anticancer activity in EGFR-overexpressing SNU-C5 human colon cancer cells. Chrysophanic acid (Chrysophanol) preferentially blocks 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 (Chrysophanol) treatment in SNU-C5 cells inhibits EGF-induced phosphorylation of EGFR and suppresses 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 also inhibits the replication of poliovirus types 2 and 3 (Picornaviridae) and poliovirus-induced cytopathic effects in BGM (Buffalo green monkey) kidney cells.

Cell Assay: The cells are seeded at 5×103 cells/mL in 96-well microplates and allowed to attach for 24 h. Chrysophanol (20, 50, 80 and 120 μM) is added to the medium at various concentrations up to 120 μM and for different durations. After treatment, cell cytotoxicity and/or proliferation is assessed by a Cell Counting Kit-8 (CCK-8). Briefly, highly water-soluble tetrazolium salt, WST-8, produces an orange colored water-soluble product, formazan. The amount of formazan dye generated by dehydrogenases in cells is directly proportional to the number of living cells.CCK-8 (10 μL) is added to each well and incubated for 3 h at 37°C, then cell proliferation and cytotoxicity are assessed by measuring the absorbance at 450 nm using a microplate reader.Three replicated wells are used for each experimental condition