Highly Water Dispersed and Stable Deinoxanthin Nanocapsule for Effective Antioxidant and Anti-inflammatory Activity

Abstract

Carotenoids are one of the most commonly occurring fat-soluble, naturally colored, physiologically active substances. They have efficient scavenging activity for reactive oxygen species (ROS), so they can eliminate oxidative stress caused by excessive ROS production and ROS that damage intracellular biomolecules and cause harmful processes such as inflammation. A carotenoid, deinoxanthin ((2R)-2,10-dihydroxy-30, 40-didehydro-10, 20-dihydro β,Ψ-caroten-4-one) (DX), has excellent antioxidant and anti-inflammatory properties, but owing to its lipophilicity, it is unfavorably dispersed in water; thus, its bioavailability is low, and its particle and color stability and physiological activity are poor owing to external factors such as light and oxygen. To overcome these drawbacks, in this study, DX-loaded nanocapsules (DX@NCs) were prepared by nanoprecipitation by loading DX into nanocapsules, which can provide high solubilization efficiency and stability. The prepared DX@NCs showed long-term stability, confirmed through dynamic light scattering, re-dispersion, and discoloration analysis for four weeks, and the optimal loading content of DX in DX@NCs was determined. The antioxidant activity of DX@NCs evaluated using the 2,2-diphenyl-1-picrylhydrazyl assay was higher than that of unloaded DX and showed high antioxidant activity even after four weeks. In addition, DX@NCs showed favorable biocompatibility according to the in vitro 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, inhibited oxidative damage to mouse NIH-3T3 fibroblasts, and showed intracellular ROS-scavenging efficacy. In particular, DX@NCs exhibited excellent anti-inflammatory efficacy by distinctly reducing NO production in vitro, as demonstrated by nitric oxide (NO) analysis. Therefore, as carriers with excellent stability, DX@NCs have the potential for cosmetic and pharmaceutical applications, with potential antioxidant and anti-inflammatory effects.