Calebin-A induces cell cycle arrest in human colon cancer cells and xenografts in nude mice

Calebin-A is a curcuminoid compound isolated from turmeric. Herein, we investigated the antiproliferative effect of calebin-A in human colon cancer cells and demonstrated that calebin-A had a more potent inhibition on cell growth compared with curcumin and tetrahydrocurcumin. In this study, calebin-A caused G2/M cycle arrest through decreasing the protein levels of cdc25A, cyclin B, cyclin A and cdc2 and increasing cyclin-dependent kinases inhibitors (CDKI) such as p53 and p21. Moreover, calebin-A increased reactive oxygen species (ROS) levels, triggered a DNA damage response and up-regulated the phosphorylation of H2AX, chk1, chk2. Furthermore, intraperitoneally administrated calebin-A on HCT116 tumour xenografts in vivo significantly decreased tumour volumes as well as reduced tumour sizes and proliferating cell nuclear antigen (PCNA) protein levels. These results have an important implication for using calebin-A as a functional food ingredient for cancer prevention.