Sardina pilchardus is a valuable source of bioactive peptides with potential applications in functional foods. In this study, we investigated the angiotensin-converting enzyme (ACE) inhibitory activity of Sardina pilchardus protein hydrolysate (SPH) produced using dispase and alkaline protease. Our results showed that the low molecular mass fractions (<3 kDa) obtained through ultrafiltration exhibited more effective ACE inhibition, as indicated by screening with ACE inhibitory activity. We further identified the low molecular mass fractions (<3 kDa) using an LC-MS/MS rapid screening strategy. A total of 37 peptides with potential ACE inhibitory activity were identified based on high biological activity scores, non-toxicity, good solubility, and novelty. Molecular docking was used to screen for peptides with ACE inhibitory activity, resulting in the identification of 11 peptides with higher -CDOCKER ENERGY and -CDOCKER INTERACTION ENERGY scores than lisinopril. The sequences FIGR, FILR, FQRL, FRAL, KFL, and KLF were obtained by synthesizing and validating these 11 peptides in vitro, all of which had ACE inhibitory activity, as well as zinc-chelating capacity. All six peptides were found to bind to the three active pockets (S1, S2, and S1’) of ACE during molecular docking, indicating that their inhibition patterns were competitive. Further analysis of the structural characteristics of these peptides indicated that all six peptides contain phenylalanine, which suggests that they may possess antioxidant activities. After experimental verification, it was found that all six of these peptides have antioxidant activities, and we also found that the SPH and ultrafiltration fractions of SPH had antioxidant activities. These findings suggest that Sardina pilchardus may be a potential source of natural antioxidants and ACE inhibitors for the development of functional foods, and using LC-MS/MS in combination with an online database and molecular docking represents a promising, effective, and accurate approach for the discovery of novel ACE inhibitory peptides.

Liposomes serve as an effective delivery system capable of encapsulating a variety of bioactive substances. However, their structural integrity is susceptible to damage from various environmental factors, which can result in the leakage of the encapsulated bioactive agents. Consequently, identifying effective strategies to enhance the stability of liposomes has become a central focus of contemporary liposome research. Surface modification, achieved by introducing a protective layer on the liposome surface, effectively reduces liposome aggregation and enhances their stability. To this end, we designed a surface modification and constructed liposomes loaded with β-carotene through co-modification with chitosan and lactoferrin, resulting in enhanced stability. This improvement was evident in terms of storage stability, light stability, and in vitro digestion stability. The study investigated the morphology, structure, and physicochemical properties of liposomes with varying degrees of modification. CS-LF co-modified liposomes exhibited significant structural changes, with particle size increasing from 257.9 ± 6.2 nm to 580.5 ± 21.5 nm, and zeta potential shifting from negative to +48.9 ± 1.3 mV. Chitosan and lactoferrin were modified on the liposome surface through electrostatic interactions and hydrogen bonding, forming a dense protective barrier on the lipid membrane. Physicochemical analysis indicated that chitosan–lactoferrin co-modification led to a more ordered arrangement of the phospholipid bilayer, reduced membrane fluidity, and increased membrane rigidity. The interactions between chitosan, lactoferrin, and phospholipids were enhanced through hydrogen bonding, resulting in a denser surface membrane structure. This structural integrity reduced membrane permeability and improved the stability of liposomes under storage conditions, UV irradiation, and in vitro digestion. Additionally, co-modified chitosan–lactoferrin liposomes effectively alleviated lipopolysaccharide-induced inflammatory damage in mouse microglial cells by increasing cellular uptake capacity, thereby enhancing the bioavailability of β-carotene. The results of this study demonstrate that chitosan–lactoferrin co-modification significantly enhances the stability of liposomes and the bioavailability of β-carotene. These findings may contribute to the development of multi-substance co-modified liposome systems, providing a more stable transport mechanism for various compounds.

We isolated and characterized tilapia-head chondroitin sulfate (TH-CS) and explored its biological activity and mechanisms of action as an oral supplement for nonalcoholic fatty liver disease (NAFLD) induced by a high-fat diet (HFD) in mice. The results showed that treatment with TH-CS for 8 weeks alleviated the development of NAFLD, as evidenced by the notable improvement in liver damage, blood lipid accumulation and insulin resistance (IR). Meanwhile, TH-CS treatment reduced the expression of proinflammatory cytokines and normalized oxidative stress. Additionally, the analysis of 16S rDNA sequencing revealed that TH-CS could restore gut microbiota balance and increase the relative abundance of short-chain fatty acid (SCFA)-producing bacteria. Furthermore, SCFAs produced by related bacteria can further improve lipid metabolism and IR by regulating lipid synthesis signals. In conclusion, TH-CS is an effective dietary supplement for the prevention of NAFLD, and may serve as a potential supplementary treatment for lipid-related metabolic syndrome.

In this study, we compared the characteristics and in vitro anti-inflammatory effects of two curcumin liposomes, prepared with golden pompano head phospholipids (GPL) and soybean lecithin (SPC). GPL liposomes (GPL-lipo) and SPC liposomes (SPC-lipo) loaded with curcumin (CUR) were prepared by thin film extrusion, and the differences in particle size, ζ-potential, morphology, and storage stability were investigated. The results show that GPL-lipo and SPC-lipo were monolayer liposomes with a relatively small particle size and excellent encapsulation rates. However, GPL-lipo displayed a larger negative ζ-potential and better storage stability compared to SPC-lipo. Subsequently, the effects of phospholipids in regulating the inflammatory response of macrophages were evaluated in vitro, based on the synergistic effect with CUR. The results showed that both GPL and SPC exerted excellent synergistic effect with CUR in inhibiting the lipopolysaccharide (LPS)-induced secretion of nitric oxide (NO), reactive oxygen species (ROS), and pro-inflammatory genes (tumor necrosis factor (TNF)-α, interleukin 1β (IL-β), and interleukin 6 (IL-6)) in RAW264.7 cells. Interestingly, GPL-lipo displayed superior inhibitory effects, compared to SPC-lipo. The findings provide a new innovative bioactive carrier for development of stable CUR liposomes with good functional properties.

Enzymatic hydrolysis can enhance the flavor of aquatic products. Nevertheless, the strong fishy odor restricts its utilization in culinary applications. This study is centered on enhancing the flavor of golden pomfret samples by promoting the Maillard reaction (MR) between golden pomfret hydrolysate (GHES) and reducing sugars. The research results demonstrate that the Maillard reaction significantly improves the sensory characteristics of GHES. It prompts the formation of diverse volatile compounds, such as aldehydes, esters, and furans. Simultaneously, it reduces the relative amounts of substances associated with fishy odor, such as 1-Octen-3-ol and Hexanal. Moreover, the Maillard reaction increases the contents of amino acids contributing to umami and sweetness, as well as 5′-nucleotides in the samples, thus enriching their umami flavor profiles. After undergoing the Maillard reaction treatment, the antioxidant capacity of the samples is also significantly enhanced (p < 0.05). This research highlights the potential of the Maillard reaction in improving both the flavor and antioxidant properties of GHES, establishing a theoretical basis for elevating the quality of golden pomfret products.

The purpose of this work was to construct liver-targeted nanoparticles based on the redox response to effectively deliver cannabidiol (CBD) for the prevention of acute liver injury (ALI). CBD-loaded nanoparticles (CBD NPs) with a particle size of 126.5 ± 1.56 nm were prepared using the polymer DA-PP-LA obtained by grafting pullulan polysaccharide with deoxycholic acid (DA) and α-lipoic acid (α-LA). CBD NPs showed typical redox-response release behavior. Interestingly, CBD NPs exhibited admirable liver targeting ability, significantly accumulated in the liver, and effectively promoted the internalization of CBD in liver cells, thus effectively reducing the H₂O₂-induced oxidative damage of HepG2 cells and avoiding apoptosis. More importantly, CBD NPs effectively prevented CCl₄-induced ALI by protecting liver function, ameliorating oxidative stress levels, inhibiting the production of inflammatory factors, and protecting the liver from histological damage. This study provides a promising strategy for achieving targeted delivery of CBD NPs in the liver, thereby effectively preventing ALI.