Curcumin is an anticancer agent, but adverse effects and low bioavailability are its main drawbacks, which drives efforts in chemical modifications of curcumin. This study evaluated antiproliferative activity and cancer cell selectivity of a curcumin derivative, curcumin nicotinate (CN), in which two niacin molecules were introduced. Our data showed that CN effectively inhibited proliferation and clonogenic growth of colon (HCT116), breast (MCF-7) and nasopharyngeal (CNE2, 5-8F and 6-10B) cancer cells with IC50 at 27.7 μM, 73.4 μM, 64.7 μM, 46.3 μM, and 31.2 μM, respectively. In cancer cells, CN induced apoptosis and cell cycle arrest at G2/M phase through a p53-mediated mechanism, where p53 was activated, p21 and pro-apoptotic proteins Bid and Bak were upregulated, and PARP was cleaved. In non-transformed human mammary epithelial cells MCF10A, CN at 50 µM had no cytotoxicity and p53 was not activated, but curcumin at 12.5 µM activated p53 and p21 and inhibited MCF10A cell growth. These data suggest that CN inhibits cell growth and proliferation through p53-mediated apoptosis and cell cycle arrest with cancer cell selectivity.
Keywords: apoptosis; cell cycle arrest; curcumin; curcumin nicotinate; p53.