Aloperine induces G2/M phase cell cycle arrest and apoptosis in HCT116 human colon cancer cells

Aloperine (ALO) is a quinolizidine alkaloid extracted from the leaves of Sophora alopecuroides (S. alopecuroides) and possesses anti-inflammatory, anti-allergenic, antitumor, and antiviral effects. In this study, when compared with seven other types of alkaloids extracted from S. alopecuroides, ALO treatment produced the most potent effects against HCT116 colon cancer cell types. ALO inhibited proliferation and induced apoptosis in HCT116 cells in a dose-and time-dependent manner as detected by MTT, clonogenic survival, and flow cytometric assays. Results of the western blot analysis and qPCR revealed that ALO increased the protein and mRNA of Bax and decreased Bcl-2 via the mitochondrial death pathway. In addition, ALO induced cell cycle arrest at the G2/M phase with a concomitant increase in p21 and p53 and a decrease in cyclin D1 and Bl. ALO also inhibited phosphatidylinositol 3-kinase/Akt and JAK/Stat3. Generally, ALO exerted a significant anti-proliferative effect via apoptotic and cell cycle arrest induction in HCT116 cells. These results suggested that ALO should be investigated further as an agent of chemotherapeutic activity in human colon cancer.