Beta casein-micelle as a nano vehicle for solubility enhancement of curcumin; food industry application

Curcumin is a potent anticancer and antioxidant natural polyphenol poorly soluble in aqueous solutions. Beta-casein (B-CN), an amphiphilic self-assembling protein that can form micellar nanostructures, could be used as a carrier system for hydrophobic therapeutic agents such as curcumin. In this study, camel B-CN was used for curcumin encapsulation. Critical micelle concentration of camel B-CN was determined at 25, 30 and 37 C using pyrene fluorescence and the solubility of curcumin was evaluated according to the solvent-evaporation technique. Presence of camel B-CN increased the solubility of curcumin at least 2500 fold. Analysis of fluorescence emission of curcumin showed that hydrophobic interactions are predominant in its formulation with B-CN. Additionally, the cytotoxicity of curcumin to human leukemia cell line K-562 was enhanced in the presence of B-CN micelles giving inhibitory concentration (IC50) values of 26.5 and 17.7 mu mol/L for free and encapsulated curcumin, respectively. Antioxidant activity of curcumin encapsulated in B-CN was higher than that of both free B-CN and curcumin. (C) 2011 Elsevier Ltd. All rights reserved.