Influence of monoglyceride on curcumin-loaded nanostructured lipid carriers: stability, antioxidant activity, digestion behavior, and intestinal absorption

Abstract

The impact of solid lipids in the lipid phase on the performance of lipid nanoparticles is closely associated with the type of solid lipids. This study aimed to investigate the effect of monoglyceride on curcumin-loaded nanostructured lipid carriers (NLC). Curcumin-loaded NLC with different glycerol monostearate (GMS) contents were developed using the hot high-pressure homogenization method. The study of physicochemical characteristics indicated that the particle size and crystallinity of NLC were related to the GMS content. The photostability study demonstrated that increasing the GMS content in the lipid phase from 0 % to 70 % resulted in an approximately 20 % enhancement in the retention ratio of curcumin in the system. GMS content influenced the 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging ability of curcumin-loaded NLC but had no significant effect on cellular antioxidant activity. During in vitro digestion, a higher GMS content led to an increase in particle size. After increasing the GMS content in the system from 0 % to 85 %, both the degree of lipolysis and the bioaccessibility decreased by over 30 %. The combination of the digestion and permeation study was used to evaluate the intestinal absorption of curcumin from NLC. There was no significant difference in the intestinal absorption of curcumin between the system with a moderate GMS content (55 %) and those without GMS. Overall analysis showed that 55 % GMS in the lipid phase might be optimal, ensuring stability and improving intestinal absorption. These results might facilitate the formulation development of NLC for the encapsulation of hydrophobic active ingredients in functional foods.