Superbase ionic liquid mediated solubilization of curcumin for improved bioavailability and anticancer efficacy

Curcumin is a promising natural drug for the treatment of various diseases ranging from cancer to Alzheimer’s. However, a major hindrance in its use as a drug is its low aqueous solubility, rapid degradation, and poor cellular uptake. In recent years, the use of ionic liquids (ILs) in biomedical applications has gained significant attention due to their unique properties and tunability. In this study, we demonstrate the capacity of the superbase ionic liquid (SBIL) 5-Methyl-1,5,7-triaza-bicyclo[4.3.0]non-6-enium acetate [mTBNH][OAc] to dissolve highly hydrophobic and water-insoluble curcumin. An optimized concentration of 4 mol.kg-1 of SBIL was used to dissolve 3.5 mg.g-1 of curcumin, resulting in a formulation (curcumin/SBIL) that could be easily dispersed in an aqueous medium. Compared to the aqueous solubility of curcumin alone, the curcumin/SBIL formulation exhibited almost an 8,000-fold increase in solubility, also demonstrating a reduction of ~ 60% of human triple-negative breast cancer epithelial cells (MDA-MB-231) viability with only 10 µg.mL-1 of curcumin (the active compound), without any cytotoxic effects on non-tumorogenic mouse fibroblasts (L929). Our study presents a straightforward methodology for improving the solubility and bioavailability of curcumin, which holds promise for its clinical application as an effective anti-cancer drug.