Antler ossified tissue has been widely used for the extraction of bioactive peptides. In this study, collagen was prepared from antler ossified tissue via acetic acid and pepsin. Five different proteases were used to hydrolyze the collagen and the hydrolysate treated by neutrase (collagen peptide named ACP) showed the highest DPPH radical clearance rate. The extraction process of ACP was optimized by response surface methodology, and the optimal conditions were as follows: a temperature of 52 °C, a pH of 6.1, and an enzyme concentration of 3200 U/g, which resulted in the maximum DPPH clearance rate of 74.41 ± 0.48%. The peptides (ACP-3) with the strongest antioxidant activity were obtained after isolation and purification, and its DPPH free radical clearance rate was 90.58 ± 1.27%; at the same time, it exhibited good scavenging activity for ABTS, hydroxyl radical, and superoxide anion radical. The study investigated the protective effect of ACP-3 on oxidative damage in HaCaT cells. The findings revealed that all groups that received ACP-3 pretreatment exhibited increased activities of SOD, GSH-Px, and CAT compared to the model group. Furthermore, ACP-3 pretreatment reduced the levels of ROS and MDA in HaCaT cells subjected to H₂O₂-induced oxidative damage. These results suggest that collagen peptides derived from deer antler ossified tissue can effectively mitigate the oxidative damage caused by H₂O₂ in HaCaT cells, thereby providing a foundation for the utilization of collagen peptides in pharmaceuticals and cosmetics.

Objective: This study aimed to investigate the role of miRNA 21-5p in regulating the differentiation of C2C12 myoblasts and intramuscular lipid droplets accumulation in myotubes.Methods: The role of miR-21-5p in the proliferation and differentiation of myofibroblasts and intracellular lipid accumulation was analyzed using bioinformatics, CCK-8 assay, quantitative real-time polymerase chain reaction, immunoblotting, immunofluorescence staining, and Oil Red O staining.Results: The analysis of porcine BodyMap transcriptome data revealed differential expression of miRNA 21-5p in skeletal muscle and adipose tissue. Bioinformatics analysis combined with a dual-luciferase reporter assay demonstrated that FBXO11 serves as a direct target of miR-21-5p. Transfection experiments involving a miR-21-5p mimic, miR-21-5p inhibitor, and si-FBXO11 in C2C12 cells showed that overexpression of miR-21-5p or silencing of FBXO11 significantly enhanced the proliferation of C2C12 cells, upregulated myogenesis-related factors, and promoted myotube formation. Furthermore, oleic acid-induced lipid accumulation in myotubes was suppressed, accompanied by reduced expression of adipogenesis-related genes. Conversely, inhibition of miR-21-5p expression produced opposite effects.Conclusion: These findings indicate that miR-21-5p promotes proliferation and differentiation while inhibiting intramyocellular lipid deposition by targeting the 3'-untranslated region of FBXO11 in myogenic cell. The results suggest that miR-21-5p could serve as a potential miRNA biomarker for regulating intramuscular adipogenesis.

In this study, we constructed an extraction process for bovine lung peptide-1 (BLP-1) derived from bovine lung tissue utilizing single-factor optimization combined with response surface methodology. We systematically analyzed its antioxidant activity, biological safety, and therapeutic mechanisms against alcoholic liver disease (ALD). In vitro experiments demonstrated that BLP-1 exhibits excellent scavenging activity against various free radicals, while exhibiting no significant cytotoxicity or hemolytic activity. In a model of H₂O₂-induced oxidative damage in HepG2 cells, BLP-1 significantly alleviated oxidative stress injury by upregulating the activities of intracellular antioxidant enzymes. Animal experiments further confirmed that BLP-1 significantly reduced serum levels of transaminase, inhibited the release of inflammatory factors, enhanced antioxidant enzyme activity, and ameliorated lipid peroxidation and pathological injury in ALD mice. By combining liquid chromatography-tandem mass spectrometry (LC-MS/MS) with bioinformatics, we screened 12 novel antioxidant peptides. Among these, the binding energies of GP9, FG6, and WG6 to Keap1 were −10.2, −9.7, and −8.7 kcal/mol, respectively, indicating their potential to modulate the antioxidant defense system through competitive inhibition of Keap1-Nrf2 interactions. This study provides a novel approach for the high-value utilization of bovine lung and the treatment of ALD, as well as a new source for the extraction of natural antioxidant peptides.