Apoptotic Effects and Cell Cycle Arrest Effects from Ethanol Extracts of Rumex japonicus Houttuyn through Regulating Akt Signaling Pathways in HCT116 Colon Cancer Cells

Rumex japonicus Houttuyn (RJE) is the root of curled dock. Previous studies have demonstrated the anti-oxidant and anti-inflammatory effects of RJE. Based on these studies, we conducted an experiment to prove RJE’s anticancer effects. A 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay confirmed a decrease in the viability of HCT116 colon cancer cells and the RJE’s cytotoxicity. We observed that the rate of cell cycle arrest increased according to RJE concentration. Western blotting confirmed the presence of the apoptotic protein. In cells treated with RJE alone or together with LY294002 (Akt inhibitor) and Nutlin-3 (mdm2 inhibitor), the difference in the inhibition of cell viability, exhibited by MTT assay and Western blotting, suggested that apoptosis is caused by the Akt/mdm2 pathway. Consequently, it was confirmed that RJE causes cell cycle arrest and induces apoptosis through the Akt/mdm2 pathway in a concentration-dependent manner.