A green method for preparation of curcuminoid-rich Curcuma longa extract and evaluation of its anticancer activity

Background: Curcuminoids, i.e., curcumin, demethoxycurcumin, and bisdemethoxycurcumin are a major active constituent of Curcuma longa L., which possess antioxidant, anti-inflammatory, antitumor, anticancer, and various other biological activities. Objective: To establish a green method for preparation of curcuminoid-rich C. longa extracts (CRE) using microwave-assisted extraction (MAE) together with a simple one-step fractionation and to investigate the anticancer activity of CRE compared with the three marker curcuminoids. Materials and Methods: MAE was used as a green extraction method, and a macroporous resin (Diaion® HP-20) column was used for fractionation of C. longa extract to produce CRE. The sulforhodamine B assay was used to evaluate in vitro anticancer activity of the curcuminoids. Results: The optimal conditions of MAE for extraction of curcuminoids are employing ethanol as the solvent and using three irradiation cycles in a microwave powered at 900 W (one cycle is 3 min power-on and 30 s power-off). The curcuminoid extract was subsequently fractionated on a Diaion® HP-20 column eluted with 55% and 60% v/v ethanol, respectively, to obtain CRE that contained total curcuminoids of 88% w/w. CRE exhibited good anticancer activities against A549, MCF-7, HeLa, and HT-29 cells, with 50% inhibitory concentration values of 5.2, 4.5, 7.5, and 8.3 μg/mL, respectively, which almost equals those of the marker curcuminoids. Conclusion: This study indicated a potential use of CRE for anticancer purposes in food and nutraceutical applications. CRE has more advantages than pure curcuminoids for industrial applications in terms of using simple, low-cost, and environmentally friendly processes.