Exploring the binding process of lutein with hydroxypropyl-β-cyclodextrin: Multispectral and molecular simulation study

Abstract

Lutein possesses various biological activities, including antioxidant and benefits for eye health, but its application is hindered by poor water solubility and chemical instability. The study utilized hydroxypropyl-β-cyclodextrin (HP-β-CD) in complexation with lutein to enhance stability. The preparation conditions of the inclusion complex (IC) were optimized using Box-Behnken design (BBD), and the IC binding mechanism was investigated and studied by multispectral and molecular docking techniques. The results indicated that the maximum encapsulation efficiency of 84.92% was obtained when shell-to-core ratio was 1:11 (g: g), stirring speed was 420 rpm, and time was 15 h. Moreover, the microstructure characterization and multispectral analysis indicate the formation of IC, with lutein exhibiting an amorphous structure. The results of molecular docking and molecular dynamics (MD) simulations further demonstrate that lutein and HP-β-CD are bound through electrostatic and hydrophobic interactions. IC exhibits higher stability compared to free lutein under varying temperatures and simulated digestive conditions, and enhance antioxidant activity. IC changes the original crystal form of lutein and improves water solubility, which may be more favorable for human absorption and utilization. Hence, encapsulating lutein with HP-β-CD may offer a promising strategy to enhance its applications in pharmaceuticals and food applications.