Mitochondria-targeted nanoparticles based on glycated oat protein for enhanced curcumin bioavailability and antioxidant activity

Abstract

Curcumin is a hydrophobic dietary supplement and can mitigate oxidative damage. However, the low bioavailability of curcumin impedes its application in functional foods. Protein-coated nanoparticles are susceptible to environmental stress and have limited ability to reach mitochondria, where reactive oxygen species are generated. To overcome this limitation, we prepared mitochondria-targeted nanoparticles by modifying glycosylated oat protein isolate with triphenylphosphonium bromide for the efficient delivery of curcumin. In this study, the curcumin was incorporated into the spherical nanoparticles with high entrapment efficiency and loading capacity. The nanoparticles increased the stability of curcumin during heat treatment and light irradiation. The bioavailability of curcumin was improved in the nanoparticles due to their strong resistance against in vitro gastric digestion and good permeability across the Caco-2 cell monolayer. The nanoparticles realized lysosomal escape and exhibited specific accumulation in mitochondria upon internalization by Caco-2 cells. The mitochondria-targeted nanoparticles with no cytotoxicity further enhanced the antioxidant activity of curcumin by preserving mitochondrial membrane potential, increasing antioxidant enzyme activities, decreasing the concentrations of intracellular reactive oxygen species and malondialdehyde. This study highlights the potential application of glycosylated proteins in developing nanocarriers for precise delivery of hydrophobic nutrients.