Nanocapsule preparation technology, as an emerging technology with great development prospects, has uniqueness and superiority in various industries. In this paper, the preparation technology of nanocapsules was systematically divided into three categories: physical methods, chemical methods, and physicochemical methods. The technological innovation of different methods in recent years was reviewed, and the mechanisms of nanocapsules prepared via emulsion polymerization, interface polymerization, layer-by-layer self-assembly technology, nanoprecipitation, supercritical fluid, and nano spray drying was summarized in detail. Different from previous reviews, the renewal iteration of core–shell structural materials was highlighted, and relevant illustrations of their representative and latest research results were reviewed. With the continuous progress of nanocapsule technology, especially the continuous development of new wall materials and catalysts, new preparation technology, and new production equipment, nanocapsule technology will be used more widely in medicine, food, cosmetics, pesticides, petroleum products, and many other fields.

In this study, we systematically investigated the mechanisms of the antioxidation and anti-lipid accumulation effects of antioxidant peptides from Litsea cubeba on a free fatty acid (FFA)-induced NAFLD model of HepG2 cells. The NAFLD cell model was constructed by inducing the HepG2 hepatocellular carcinoma cell line with 0.5 mmol/L FFAs, and AQRDAGLL, QEGPFVR, and DVPPPRGPL were given to the culture to study their lipid-lowering and antioxidant activities on NAFLD cells. The lipid-lowering activities of the three antioxidant peptides were evaluated by Oil Red O staining and TG and TC content assays, and the results showed that all three peptides had strong ameliorating effects on FFA-induced lipid accumulation in NAFLD cells. The intracellular antioxidant protease (CAT, GSH, and SOD) activity levels and lipid peroxidation (MDA) content were measured and intracellular ROS levels were detected. The results showed that after intervention with the antioxidant peptides, the intracellular ROS levels in the NAFLD model cells were significantly reduced, the SOD and CAT activities were increased, the GSH content was elevated, and the MDA content was reduced, which indicated that AQRDAGLL, QEGPFVR, and DVPPPRGPL were able to inhibit the oxidative stress of the cells effectively and to achieve the effect of intervening in NAFLD. JC-1 fluorescence staining experiments showed that the mitochondrial membrane potential function of NAFLD cells was restored under the effect of the antioxidant peptides. Molecular dynamics simulations revealed that the main driving force between QEGPFVR and Keap1 protein was van der Waals forces, ΔG = −62.11 kcal/mol, which indicated that QEGPFVR was capable of spontaneously binding to Keap1 protein.