Silica–Containing Redox Nanoparticles Improve the Antioxidant Activity of Curcumin and its Gastrointestinal Biodistribution Evaluation

Abstract

This study aimed to evaluate the antioxidant potential of designed silica-containing redox nanoparticles (siRNP) to improve curcumin's stability and gastrointestinal (GI) distribution via oral administration. Curcumin-loaded silica-containing redox nanoparticles (CUR@siRNP) were prepared by dialysis, resulting in a particle size of approximately 100 nm. Curcumin was degraded by oxidizing agents including 2,2'-azobis (2-amidinopropane) dihydrochloride) and hydrogen peroxide, while siRNP effectively protected the encapsulated curcumin from oxidative degradation. In addition, CUR@siRNP showed significantly higher antioxidant activities in protein carbonyl assay and lipid peroxidation assay than free curcumin. Furthermore, CUR@siRNP remarkably suppressed the toxicity of curcumin against normal fibroblasts L929 cell line by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The GI distribution in vivo showed that CUR@siRNP improved the accumulation of curcumin in the small intestine and colon after oral administration. The results of this study suggested that the CUR@siRNP nanoparticles exhibited great potential carriers for the oral delivery of curcumin in the treatment of GI inflammation.