Impact of excipient emulsions made from different types of oils on the bioavailability and metabolism of curcumin in gastrointestinal tract.

Abstract

Low bioavailability currently limits the potential of curcumin as a health-promoting dietary compound. This study therefore explored the potential of excipient emulsions to improve curcumin bioavailability. Oil-in-water excipient emulsions were prepared using different types of oils: corn oil, olive oil, and medium chain triglycerides (MCT). The excipient emulsions increased the transportation rate of curcumin across the Caco-2 cell monolayer and showed ability to protect curcumin from metabolism in the enterocytes, with the olive oil-based systems exhibiting the highest efficacy. In addition, most of curcumin metabolites were present as hexahydro-curcumin (HHC) and its conjugates. Our results show that excipient emulsions can improve curcumin bioavailability by increasing its trans-enterocyte absorption and reducing cellular metabolism. Moreover, they show that these effects depend on the type of oil used to produce them. These findings have important implications for the rational design of lipid-based delivery systems to enhance the bioavailability of hydrophobic nutraceuticals like curcumin.