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Dipeptidyl peptidase IV (DPP-IV) inhibitors are widely used in treating type 2 diabetes due to their ability to lower blood glucose levels. However, synthetic versions often lead to gastrointestinal side effects. This study explores DPP-IV inhibitory properties in peptides from bighead carp skin. Collagen was prepared, hydrolyzed into collagen peptides, and then fractionated for DPP-IV inhibitory activity examination. The most effective fractions were identified, and their peptide sequences were determined. Molecular docking analysis identified nine peptides with potential inhibitory activity, four of which (VYP, FVA, PPGF, PGLVG) were synthesized and tested in vitro. PPGF exhibited the highest potency with an IC50 of 4.63 nM, competitively binding to key DPP-IV sites, including ARG125, VAL711, TYR666, and TYR662. Other peptides showed varying effectiveness, with IC50 values of 398.87 nM (VYP), 402.02 nM (FVA), and 110.20 nM (PGLVG). These findings highlight bighead carp skin peptides as potent DPP-IV inhibitors with hypoglycemic potential, suggesting a novel avenue for diabetes management using natural peptides. Moreover, this research underscores the utilization of bighead carp by-products, contributing to environmental sustainability. [ABSTRACT FROM AUTHOR]

Copyright of China Condiment is the property of China Condiment and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Immunodeficiency can disrupt normal physiological activity and function. In this study, donkey bone collagen peptide (DP) and its iron chelate (DPI) were evaluated their potential as immunomodulators in cyclophosphamide (Cytoxan®, CTX)-induced Balb/c mice. The femoral tissue, lymphocytes, and serum from groups of mice were subjected to hematoxylin and eosin (H&E) staining, methylthiazolyldiphenyl-tetrazolium bromide (MTT) cell proliferation assays, and enzyme-linked immunosorbent assay (ELISA), respectively. Furthermore, a non-targeted metabolomics analysis based on UPLC–MS/MS and a reverse transcription polymerase chain reaction (RT-qPCR) technology were used to explore the specific metabolic pathways of DPI regulating immunocompromise. The results showed that CTX was able to significantly reduce the proliferative activity of mouse splenic lymphocytes and led to abnormal cytokine expression. After DP and DPI interventions, bone marrow tissue damage was significantly improved. In particular, DPI showed the ability to regulate the levels of immune factors more effectively than Fe2+ and DP. Furthermore, metabolomic analysis in both positive and negative ion modes showed that DPI and DP jointly regulated the levels of 20 plasma differential metabolites, while DPI and Fe2+ jointly regulated 14, and all 3 jointly regulated 10. Fe2+ and DP regulated energy metabolism and pyrimidine metabolism pathways, respectively. In contrast, DPI mainly modulated the purine salvage pathway and the JAK/STAT signaling pathway, which are the key to immune function. Therefore, DPI shows more effective immune regulation than Fe2+ and DP alone, and has good application potential in improving immunosuppression. [ABSTRACT FROM AUTHOR]

BACKGROUND: Sturgeon is a popular aquaculture species in many countries. Its swim bladder is rich in collagen but has not yet been exploited scientifically. RESULTS: Collagen peptides (CPs) prepared from sturgeon swim bladder by trypsinolysis had an average molecular weight of 528.5 Da and consisted of 407 peptides, 16.1% of the content of which was GFPGADGSAGPK. The CPs at 25 mg mL‐1 extended the lifespan of Caenorhabditis elegans by 22.6%, which was significantly higher than the extension achieved by other hydrolysis methods and source materials. They also improved fitness‐related traits (body size, motor capacity, oxidative stress, cell apoptosis, and epidermal barrier function), indicating prolonged healthspan. Transcriptome analysis showed that the effect was mediated by the mitogen‐activated protein kinase pathway, which enhanced stress resistance, the insulin/IGF‐1 pathway, which inhibited protein aggregation, and the NHR‐80/FAT‐6 pathway, which regulated lipid metabolism. CONCLUSION: Collagen peptides from sturgeon swim bladder by trypsinolysis prolonged the lifespan and healthspan in C. elegans, and might be promising anti‐aging agents. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Insufficient research on the material basis and functional product development of horse bones has led to the waste of resources. This paper, as the by-product of horse meat bone marrow was the object, aimed to discover the flavor and antioxidant activity of novel collagen peptides. Two peptides, HBMP-1-1 and HBMP-2-1, were isolated and purified from horse bone marrow collagen protein (HBMP) hydrolysates. The combination of spectroscopic and chromatographic methods including SDS-PAGE, UV, FT-IR, CD, and SEM identified the structures of the peptides. The amino acid composition, flavor characteristics, and antioxidant activity were also evaluated. SDS-PAGE analysis showed that the molecular weight of the two peptides was concentrated under 4.1 kDa. The total amino acid contents of the HBMP-1-1 was up to 570.779 mg/g. Leucine, alanine, and glutamicacid were the predominant amino acids in HBMP-1-1 with high nutritional value, and it contained 10.07% β-folding, 46.39% β-turn, and 43.54% random coil structure. The peptide sequences IDDPTDSKPE, LNGKLTGM, ELDEGYVPK, AFQEDPDKF, and FVGKVVDPTQK with molecular weights of 1116.51, 833.45, 1049.51, 1096.49, and 1217.69 Da were detected using LC-MS/MS. The results of the antioxidant activity test showed that separation and purification significantly improved the bioactivity of the protein. The half-inhibition rate of HBMP-1-1 against DPPH, ABTS, and hydroxyl radicals were 0.054, 0.050, and 0.137 mg/mL, respectively. This article provides a scientific basis for clarifying the material basis of horse bone marrow collagen peptides. Also, it provides new approaches and ideas for exploring efficient and safe bone-derived lead compounds and products. [ABSTRACT FROM AUTHOR]

Skin problems caused by aging have attracted much attention, and marine collagen peptides have been proved to improve these problems, while mammalian collagen peptides are rarely reported. In this study, fermented deer bone collagen peptide (FCP) and non-fermented deer bone collagen peptide (NCP) were extracted from fermented and non-fermented deer bone, respectively, and their peptide sequences and differential proteins were analyzed using LC-MS/MS technology. After they were applied to aging mice induced with D-gal, the skin hydration ability, antioxidant ability, collagen synthesis, and degradation ability of the mice were studied. The results show that FCP and NCP are mainly peptides that constitute type Ⅰ collagen, and their peptide segments are different. In vivo experiments show that FCP and NCP can improve the richness of collagen fibers in the skin of aging mice; improve the hydration ability of skin; promote the activity of antioxidant-related enzymes; and also show that through the TGF-β and MAPK pathways, the synthesis and degradation of collagen in skin are regulated. These results show that deer bone collagen peptide can improve skin problems caused by aging, promote skin hydration and antioxidant capacity of aging mice, and regulate collagen synthesis and degradation through the MAPK pathway. [ABSTRACT FROM AUTHOR]

The purpose of this research was to explore the impact of collagen peptides derived from cod (Gadus) skin on H2O2-induced 2BS senescence cells. The senescence model induced by H2O2 was established to determine the cell proliferation rate, ROS level, cell apoptosis, and peroxidase content after the intervention of the optimal dose of collagen peptides. Collagen peptides effectively suppressed apoptosis in 2BS senescence cells, substantially decreasing ROS and MDA levels. Furthermore, SOD and CAT activities were significantly elevated. In summary, collagen peptides have demonstrated a significant capacity to impede the process of cellular senescence in 2BS cells through the reduction of oxidative stress and apoptosis. [ABSTRACT FROM AUTHOR]

A meta-analytical technique was applied to the evaluation of the functionality of collagen peptide health functional food ingredients (n = 6, until Feb. ’23) recognized in Korea for 7 interventions, with a total of 564 participants. The effect size was assessed using the standardized mean difference (SMD), and detailed subgroup analyses were conducted in the presence of heterogeneity. As a result of evaluating functionality, effective results were shown in the test group compared with placebo in terms of skin wrinkles (SMD 0.5), and skin elasticity (SMD > 0.5). R3 and Ra, which are the parameters of average skin roughness measured by the visiometer and the PRIMOS respectively, showed the largest SMD. Skin hydration significantly increased on the cheek site measured by the corneometer, which is predominantly used for the measurement of skin moisture. The scientific evidence for the skin-related functionalities of recognized collagen peptides was confirmed through meta-analytical approaches.

Background: Oral collagen peptides supplementation was reported to improve skin integrity and counteract skin aging. Aims: A randomized, double‐blinded, placebo‐controlled study was conducted to clinically evaluate the impact of low‐molecular‐weight collagen peptides on the human skin. Patients/Methods: Healthy adult participants (n = 100) were randomly assigned to receive a test product containing low‐molecular‐weight collagen peptides or a placebo. Parameters of skin wrinkles, elasticity, hydration, and whitening (melanin and erythema indexes) were measured at baseline and after 4, 8, and 12 weeks. Results: Compared with the placebo group, the average skin roughness, maximum of all peak‐to‐valley values, maximum peak height of the wrinkle, and average maximum height of the wrinkle were significantly improved in the test group. Parameters of skin elasticity, including overall elasticity, net elasticity, and biological elasticity, were also significantly improved in the test group at Week 12 as compared with the placebo group. Moreover, skin hydration and whitening parameters changed more significantly in the test group than in the placebo group. None of the participants experienced adverse events related to the test product. Conclusions: Taken together, these findings suggest that low‐molecular‐weight collagen peptides supplementation can safely ehance human skin wrinkling, hydration, elasticity, and whitening properties. [ABSTRACT FROM AUTHOR]

A bioactive compound, collagen peptide (CP), is widely used for biological activities such as anti-photoaging and antioxidant effects, with increased oral bioavailability because of its low molecular weight and high hydrophilicity. However, controlling release time and increasing retention time in the digestive tract for a more convenient oral administration is still a challenge. We developed CP-loaded chitosan (CS) microcapsules via strong and rapid ionic gelation using a highly negative phytic acid (PA) crosslinker. The platform enhanced the oral bioavailability of CP with controlled gastrointestinal delivery by utilizing the mucoadhesiveness and tight junction-opening properties of CS. CS and CP concentrations varied from 1.5 to 3.5% and 0–30%, respectively, for optimal and stable microcapsule synthesis. The physicochemical properties, in vitro release profile with intestinal permeability, in vivo oral bioavailability, in vivo biodistribution, anti-photoaging effect, and antioxidant effect of optimized CS microcapsules were analyzed to investigate the impact of controlling parameters. The structure of CS microcapsules was tuned by PA diffused gradient ionic cross-linking degree, resulting in a controlled CP release region in the gastrointestinal tract. The optimized microcapsules increased C max , AUC, and t max by 1.5-, 3.4-, and 8.0-fold, respectively. Furthermore, CP in microcapsules showed anti-photoaging effects by downregulating matrix metalloproteinases-1 via antioxidant effects. According to our knowledge, this is the first study to microencapsulate CP for oral bioavailability enhancement. The peptide delivery method employed is simple, economical, and can be applied to customize bioactive compound administration. [Display omitted] [ABSTRACT FROM AUTHOR]

BackgroundThe global obesity epidemic is a significant public health issue, often leading to metabolic disorders such as diabetes and cardiovascular diseases. Collagen peptides (CP) and their bioactive component, Prolyl-hydroxyproline (Pro-Hyp), have shown potential in reducing adipocyte size, with unclear mechanisms concerning brown adipocyte differentiation.MethodsWe investigated the effects of Pro-Hyp on the differentiation of brown adipocytes in C3H10T1/2 mesenchymal stem cells, focusing on its impact on adipocyte size, gene expression related to brown fat function, and mitochondrial activity.ResultsPro-Hyp treatment decreased adipocyte size and upregulated brown fat-specific genes, including C/EBPα, PGC-1α, and UCP-1. Remarkably, it did not alter PPARγ expression. Pro-Hyp also elevated mitochondrial activity, suggesting enhanced brown adipocyte functionality. A Pro-Hyp responsive element was identified in the PGC-1α gene promoter, which facilitated the binding of the Foxg1 transcription factor, indicating a novel regulatory mechanism.ConclusionPro-Hyp promotes brown adipocyte differentiation, potentially offering a therapeutic strategy for obesity management. This study provides a molecular basis for the anti-obesity effects of CP, although further in vivo studies are needed to confirm these findings and to investigate the potential impact on beige adipocyte differentiation.

Dipeptidyl peptidase IV (DPP-IV) inhibitors are widely used in treating type 2 diabetes due to their ability to lower blood glucose levels. However, synthetic versions often lead to gastrointestinal side effects. This study explores DPP-IV inhibitory properties in peptides from bighead carp skin. Collagen was prepared, hydrolyzed into collagen peptides, and then fractionated for DPP-IV inhibitory activity examination. The most effective fractions were identified, and their peptide sequences were determined. Molecular docking analysis identified nine peptides with potential inhibitory activity, four of which (VYP, FVA, PPGF, PGLVG) were synthesized and tested in vitro. PPGF exhibited the highest potency with an IC50 of 4.63 nM, competitively binding to key DPP-IV sites, including ARG125, VAL711, TYR666, and TYR662. Other peptides showed varying effectiveness, with IC50 values of 398.87 nM (VYP), 402.02 nM (FVA), and 110.20 nM (PGLVG). These findings highlight bighead carp skin peptides as potent DPP-IV inhibitors with hypoglycemic potential, suggesting a novel avenue for diabetes management using natural peptides. Moreover, this research underscores the utilization of bighead carp by-products, contributing to environmental sustainability.

Immunodeficiency can disrupt normal physiological activity and function. In this study, donkey bone collagen peptide (DP) and its iron chelate (DPI) were evaluated their potential as immunomodulators in cyclophosphamide (Cytoxan®, CTX)-induced Balb/c mice. The femoral tissue, lymphocytes, and serum from groups of mice were subjected to hematoxylin and eosin (H&E) staining, methylthiazolyldiphenyl-tetrazolium bromide (MTT) cell proliferation assays, and enzyme-linked immunosorbent assay (ELISA), respectively. Furthermore, a non-targeted metabolomics analysis based on UPLC–MS/MS and a reverse transcription polymerase chain reaction (RT-qPCR) technology were used to explore the specific metabolic pathways of DPI regulating immunocompromise. The results showed that CTX was able to significantly reduce the proliferative activity of mouse splenic lymphocytes and led to abnormal cytokine expression. After DP and DPI interventions, bone marrow tissue damage was significantly improved. In particular, DPI showed the ability to regulate the levels of immune factors more effectively than Fe2+ and DP. Furthermore, metabolomic analysis in both positive and negative ion modes showed that DPI and DP jointly regulated the levels of 20 plasma differential metabolites, while DPI and Fe2+ jointly regulated 14, and all 3 jointly regulated 10. Fe2+ and DP regulated energy metabolism and pyrimidine metabolism pathways, respectively. In contrast, DPI mainly modulated the purine salvage pathway and the JAK/STAT signaling pathway, which are the key to immune function. Therefore, DPI shows more effective immune regulation than Fe2+ and DP alone, and has good application potential in improving immunosuppression.

Purpose: Sturgeon notochord, a by-product in the sturgeon aquaculture industry, is a promising yet underutilized source of type II collagen. In this study, functionally enhanced collagen peptides (CPs) were developed from notochordal collagen using optimal glycation via the Maillard reaction, and the potential applications of the by-product and possible contributions to the valorization of the sturgeon aquaculture industry were determined. Methods: CP prepared by papain digestion was mixed with alginate oligosaccharide (AO), glucose (Glu), or glucuronic acid (GluA), lyophilized, and then glycation at 80 °C and 75% relative humidity for up to 8 h. Amino acid analysis was performed to evaluate the formation of glycated CP (CP–sugars). The health-beneficial functions, antioxidative and anti-inflammatory activities of CP–sugars were evaluated by the ABTS radical scavenging assay and by quantification of inflammatory compound (tumor necrosis factor-α and nitric oxide) production in LPS-stimulated macrophages, respectively. Results: During the glycation process, reducing sugars were reacted with lysine and arginine in CP. GluA had a higher reactivity to the reactive amino acids than that of Glu and AO. The antioxidant and anti-inflammatory functions of CP–sugars were increased with the glycation processes, and AO-glycation enhanced the health-beneficial functions of CP without a marked loss of reactive amino acids compared with the Glu- and GluA-glycations. Conclusion: The appropriate glycation via the Maillard reaction is an effective way to simultaneously enhance the antioxidant and anti-inflammatory functions of CP from sturgeon notochord to facilitate its application as a functional food material. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Abstract Background The management of knee osteoarthritis involves various treatment strategies. It is important to explore alternative therapies that are both safe and effective. Collagen peptides have emerged as a potential intervention for knee osteoarthritis. This study aims to evaluate the analgesic effects and safety of collagen peptide in patients diagnosed with knee osteoarthritis. Methods We conducted a systematic literature search following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Multiple databases including PubMed, Scopus, EMBASE, Web of Science, Cochrane, and ClinicalTrials.gov were searched for randomized controlled trials (RCTs) published up to 27 May 2023 that focused on the analgesic outcomes and adverse events associated with collagen peptides or hydrolyzed collagen in patients with osteoarthritis. We assessed the quality of the included studies and the strength of evidence using the Cochrane ROB 2.0 tool and Grading of Recommendations, Assessment, Development, and Evaluations. Results Four trials involving 507 patients with knee osteoarthritis were included and analyzed using the random-effects model. All these trials were considered to have a high risk of bias. Our results revealed a significant difference in pain relief between the collagen peptide group and the placebo group in patients with knee osteoarthritis (standardized mean difference: − 0.58; 95% CI − 0.98, − 0.18, p = 0.004; I2: 68%; quality of evidence: moderate). However, there was no significant difference in the risk of adverse events between collagen peptide and placebo (odds ratio: 1.66; 95% CI 0.99, 2.78, p = 0.05; I2: 0%; quality of evidence: very low). Conclusions Our findings demonstrate significant pain relief in patients with knee osteoarthritis who received collagen peptides compared to those who received placebo. In addition, the risk of adverse events did not differ significantly between the collagen peptide group and the placebo group. However, due to potential biases and limitations, well-designed randomized controlled trials are needed to validate and confirm these findings.

Collagen peptides (CPs) are food-derived peptides that possess a variety of bioactive properties. Our study investigates the effects of CP on pulmonary fibrosis in bleomycin (BLM)-treated mice. C57BL/6J mice were subcutaneously injected with BLM for two weeks followed by a three-week experimental diet containing 25 mg/g of CP derived from chicken feet. Supplementation with CP suppressed the increase in lung weight and disruption of lung architecture observed in mice treated with BLM. BLM-treated mice also exhibited higher hydroxyproline content and increased expression levels of type I and III collagen subunit genes in the lungs. CP supplementation exerted no effect on these collagen-related factors; however, it significantly suppressed the gene expression of fibronectin and inflammation-related molecules in the lungs of BLM-treated mice. These findings suggest that CP administration prevents the development of pulmonary fibrosis by acting as an anti-inflammatory agent.

Skin problems caused by aging have attracted much attention, and marine collagen peptides have been proved to improve these problems, while mammalian collagen peptides are rarely reported. In this study, fermented deer bone collagen peptide (FCP) and non-fermented deer bone collagen peptide (NCP) were extracted from fermented and non-fermented deer bone, respectively, and their peptide sequences and differential proteins were analyzed using LC-MS/MS technology. After they were applied to aging mice induced with D-gal, the skin hydration ability, antioxidant ability, collagen synthesis, and degradation ability of the mice were studied. The results show that FCP and NCP are mainly peptides that constitute type Ⅰ collagen, and their peptide segments are different. In vivo experiments show that FCP and NCP can improve the richness of collagen fibers in the skin of aging mice; improve the hydration ability of skin; promote the activity of antioxidant-related enzymes; and also show that through the TGF-β and MAPK pathways, the synthesis and degradation of collagen in skin are regulated. These results show that deer bone collagen peptide can improve skin problems caused by aging, promote skin hydration and antioxidant capacity of aging mice, and regulate collagen synthesis and degradation through the MAPK pathway.

In order to determine the effect of ultrasonic extraction on the content and functional activity of collagen peptide from Tibetan sheep skin, solid-liquid ratio, ultrasonic power and ultrasonic time were studied by response surface method to determine the best ultrasonic extraction process of collagen peptide. The antioxidant capacity, reduction power and ·OH scavenging ability of collagen peptide from Tibetan sheep skin was analyzed. The results showed that ultrasound-assisted treatment had significantly affected the content of collagen peptide and antioxidant activity. The optimal ultrasonic extraction conditions were solid-liquid ratio 1:18, ultrasonic power 220 W and ultrasonic time 27 min. The collagen peptide content of Tibetan sheep skin was 30.21%±1.67%. The reduction power and ·OH scavenging rate of collagen peptide after ultrasonic assisted extraction were 0.49 and 83.2%, which were increased by 4% and 38.3% compared with those before ultrasonic extraction, respectively. After gastrointestinal digestion, the reduction power and ·OH decreased to a certain extent, but still had good antioxidant activity. Ultrasound-assisted extraction of collagen peptide from Tibetan sheep skin has the advantages of increasing the content of collagen peptide and enhancing antioxidant activity in vivo, which provides data reference for the development of functional products.

Background: The management of knee osteoarthritis involves various treatment strategies. It is important to explore alternative therapies that are both safe and effective. Collagen peptides have emerged as a potential intervention for knee osteoarthritis. This study aims to evaluate the analgesic effects and safety of collagen peptide in patients diagnosed with knee osteoarthritis. Methods: We conducted a systematic literature search following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Multiple databases including PubMed, Scopus, EMBASE, Web of Science, Cochrane, and ClinicalTrials.gov were searched for randomized controlled trials (RCTs) published up to 27 May 2023 that focused on the analgesic outcomes and adverse events associated with collagen peptides or hydrolyzed collagen in patients with osteoarthritis. We assessed the quality of the included studies and the strength of evidence using the Cochrane ROB 2.0 tool and Grading of Recommendations, Assessment, Development, and Evaluations. Results: Four trials involving 507 patients with knee osteoarthritis were included and analyzed using the random-effects model. All these trials were considered to have a high risk of bias. Our results revealed a significant difference in pain relief between the collagen peptide group and the placebo group in patients with knee osteoarthritis (standardized mean difference: − 0.58; 95% CI − 0.98, − 0.18, p = 0.004; I2: 68%; quality of evidence: moderate). However, there was no significant difference in the risk of adverse events between collagen peptide and placebo (odds ratio: 1.66; 95% CI 0.99, 2.78, p = 0.05; I2: 0%; quality of evidence: very low). Conclusions: Our findings demonstrate significant pain relief in patients with knee osteoarthritis who received collagen peptides compared to those who received placebo. In addition, the risk of adverse events did not differ significantly between the collagen peptide group and the placebo group. However, due to potential biases and limitations, well-designed randomized controlled trials are needed to validate and confirm these findings. [ABSTRACT FROM AUTHOR]

Collagen peptides (CPs) are food-derived peptides that possess a variety of bioactive properties. Our study investigates the effects of CP on pulmonary fibrosis in bleomycin (BLM)-treated mice. C57BL/6J mice were subcutaneously injected with BLM for two weeks followed by a three-week experimental diet containing 25 mg/g of CP derived from chicken feet. Supplementation with CP suppressed the increase in lung weight and disruption of lung architecture observed in mice treated with BLM. BLM-treated mice also exhibited higher hydroxyproline content and increased expression levels of type I and III collagen subunit genes in the lungs. CP supplementation exerted no effect on these collagen-related factors; however, it significantly suppressed the gene expression of fibronectin and inflammation-related molecules in the lungs of BLM-treated mice. These findings suggest that CP administration prevents the development of pulmonary fibrosis by acting as an anti-inflammatory agent. [ABSTRACT FROM AUTHOR]

This study aims to isolate collagen peptides from waste sturgeon fish skin, and prepare nanoemulsions for studying their anti-diabetic and wound-healing effects in mice. Collagen peptides were extracted and purified by acetic acid with sonication, followed by two-stage hydrolysis with 0.1% pepsin and 5% flavourzyme, and ultrafiltration with 500 Da molecular weight (MW) cut-off dialysis membrane. Animal experiments were performed with collagen peptides obtained by pepsin hydrolysis (37 kDa) and pepsin plus flavourzyme hydrolysis (728 Da) as well as their nanoemulsions prepared at two different doses (100 and 300 mg/kg/day). The mean particle size of low-MW and low-dose nanoemulsion, low-MW and high-dose nanoemulsion, high-MW and low-dose nanoemulsion and high-MW and high-dose nanoemulsion was, respectively, 16.9, 15.3, 28.1 and 24.2 nm, the polydispersity index was 0.198, 0.215, 0.231 and 0.222 and zeta potential was −61.2, −63.0, −41.4 and −42.7 mV. These nanoemulsions were highly stable over a 90-day storage period (4 °C and 25 °C) and heating at 40–100 °C (0.5–2 h). Experiments in mice revealed that the low-MW and high-dose nanoemulsion was the most effective in decreasing fasting blood glucose (46.75%) and increasing wound-healing area (95.53%). Collectively, the sturgeon fish skin collagen peptide-based nanoemulsion is promising for development into a health food or wound-healing drug. [ABSTRACT FROM AUTHOR]

BACKGROUND: Collagen peptide is a low molecular active peptide obtained by hydrolysis of collagen. It can be digested and absorbed, and participate in protein synthesis and metabolism in the human body. It has a positive effect on skin health. However, the absorption and delivery mechanism of collagen peptides is not completely clear, and another problem is its low bioavailability. OBJECTIVE: To explore the potential measures to increase the bioavailability of collagen peptides for promoting skin health. METHODS: The articles related to the preparation, composition, digestion and bioavailability of collagen peptide, skin structure, photoaging and natural aging, transport mechanism of collagen peptide by oral in vivo, transdermal absorption mechanism of collagen peptide, and synergistic absorption of collagen peptide with other substances, were searched on ScienceDirect, PubMed, CNKI, Sci-Hub, and Baidu Academic Database from January 2009 to March 2022. The main keywords used were “collagen, collagen peptide, preparation of collagen peptide, photoaging, percutaneous absorption of collagen peptide” in Chinese and “collagen, collagen peptide, preparation of collagen peptide, photoaging, oral absorption” in English. Finally, 82 articles were included for review. RESULTS AND CONCLUSION: (1) Photoaging and natural aging cause skin tissue damage. Collagen peptides can be transported to the skin through the blood after oral gastrointestinal digestion, and build skin tissue through internal molecular mechanisms, and can also be absorbed through the skin surface to have a positive effect on the dermis. (2) At present, the bioavailability of oral collagen peptide is low, and its delivery mechanism is mainly concentrated in the gastrointestinal stage, and there is also the problem of excessive epidermal resistance in percutaneous absorption. (3) The source, amino acid composition, peptide sequence, molecular weight and dosage of collagen peptide and synergistic absorption with different substances or enzyme cofactors should be paid more attention, looking for more high-quality delivery carriers to improve the bioavailability of collagen peptides. (4) For percutaneous absorption, advanced technology or improved physical and chemical methods should be applied to reduce skin physical resistance or improve molecular penetration efficiency. (5) In future, both oral and percutaneous absorption of collagen peptide could be used to recover skin tissue problems caused by photoaging and natural aging more quickly and effectively. [ABSTRACT FROM AUTHOR]

Alterations in the intestinal microbial flora are known to cause various diseases, and many people routinely consume probiotics or prebiotics to balance intestinal microorganisms and the growth of beneficial bacteria. In this study, we selected a peptide from fish (tilapia) skin that induces significant changes in the intestinal microflora of mice and reduces the Firmicutes/Bacteroidetes ratio, which is linked to obesity. We attempted to verify the anti-obesity effect of selected fish collagen peptides in a high-fat-diet-based obese mouse model. As anticipated, the collagen peptide co-administered with a high-fat diet significantly inhibited the increase in the Firmicutes/Bacteroidetes ratio. It increased specific bacterial taxa, including Clostridium_sensu_stricto_1, Faecalibaculum, Bacteroides, and Streptococcus, known for their anti-obesity effects. Consequently, alterations in the gut microbiota resulted in the activation of metabolic pathways, such as polysaccharide degradation and essential amino acid synthesis, which are associated with obesity inhibition. In addition, collagen peptide also effectively reduced all obesity signs caused by a high-fat diet, such as abdominal fat accumulation, high blood glucose levels, and weight gain. Ingestion of collagen peptides derived from fish skin induced significant changes in the intestinal microflora and is a potential auxiliary therapeutic agent to suppress the onset of obesity. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Collagen-derived dipeptides and tripeptides have various physiological activities. In this study, we compared the plasma kinetics of free Hyp, peptide-derived Hyp, Pro-Hyp, cyclo(Pro-Hyp), Hyp-Gly, Gly-Pro-Hyp, and Gly-Pro-Ala after ingestion of four different collagen samples: AP collagen peptide (APCP), general collagen peptide, collagen, and APCP and γ-aminobutyric acid (GABA) combination. Each peptide was measured by high-performance liquid chromatography and triple quadrupole mass spectrometer. We found that, among all the peptides that were analyzed, only Gly-Pro-Hyp was significantly increased after ingestion of APCP compared with that of general collagen peptides and collagen. In addition, ingestion of the APCP and GABA combination improved the absorption efficiency of Gly-Pro-Ala. Finally, we reveal that Gly-Pro-Hyp was effective for preventing H2O2-induced reduction in extracellular matrix (ECM)-related genes, COL1A, elastin, and fibronectin, in dermal fibroblasts. Taken together, APCP significantly enhances the absorption of Gly-Pro-Hyp, which might act as an ECM-associated signaling factor in dermal fibroblasts, and the APCP and GABA combination promotes Gly-Pro-Ala absorption. Clinical Trial Registration number: UMIN000047972. [ABSTRACT FROM AUTHOR]

This study attempts to identify the significant role played by the secondary and tertiary structure of collagen-derived peptides that are involved in lipid peroxide quenching in food products. Fish collagen hydrolysate (CH) was extracted with an efficiency of 70%. The constituent peptides of CH (8.2–9.7 kDa) existed in a polyproline-II (PP-II) conformation and at a minimum concentration of 1 mg ml−1 and pH range 7 to 8, assembled into a stable, hierarchical, quasi-fibrillar (QF) network. The peroxide quenching activity of this QF-CH increased with increasing ionic stability of the assembly and decreased upon proteolytic dismantling. Upon being used as an additive, the QF-CH reduced peroxide formation by 84.5% to 98.9% in both plant and fish-based oil and increased the shelf life of soya oil by a factor of 5 after 6 months of storage. The addition of QF-CH to cultured cells quenched peroxide ions generated in situ and decreased stressor activity by a factor of 12.16 abundant peptides were identified from the CH. The reason behind the high efficacy displayed by CH was attributed to its unique charge distribution, prevalence of proton-donating amino acid residues and proximal charge delocalization by the QF network, making fish derived CH a suitable substitute for antiperoxide agents in lipid-rich food. [ABSTRACT FROM AUTHOR]

Seabass (Lates calcarifer) is one of the top farmed and raised fish in Taiwan, and fish scales are the main by-product after processing. Fish scales contain high amounts of collagen, which can chelate with minerals and enhance mineral absorption in the human body. Hence, fish scales from seabass were enzymatically hydrolyzed to obtain seabass scale collagen peptide (SBSCP). Calcium, the most consumed mineral supplement, was chelated with SBSCP to form SBSCP-Ca. The optimal conditions for chelation were a peptide/calcium ratio: 1:1 (w/w), pH 5.0, and 50 °C for 20 min. The conjugated sites were carboxyl and amino groups based on Fourier transform infrared (FTIR) spectroscopy. Scanning electronic microscope/energy-dispersive X-ray spectroscopy (SEM/EDS) evidently showed the alternation of SBSCP's molecular structure after chelation and increased concentrations of metal ions. SBSCP-Ca was stable up to 90 °C and from pH 2.0 to 5.0. The retention rate was 70%, as determined after in vitro digestion. The extracts of blackcurrant or berry-grape seeds were added to neutralize the fishy odor and provide antioxidant ability for commercialization. This is the first complete study of the characteristics of SBSCP-Ca as well as their commercialization. [ABSTRACT FROM AUTHOR]

This study involves the preparation of scale collagen peptides (SCPs) with whitening activity from silver carp (Hypophthalmichthys molitrix) and their characterization and peptide sequence identification. In this article, scanning electron microscopy (SEM) was used to observe structure changes of sliver carp scales; enzymatic hydrolysis was optimized through protease screening and response surface optimization. The ultrafiltration was used to separate SCPs and the whitening activity was comprehensively evaluated using radical scavenging rate and tyrosinase-inhibiting activity, among others. An optimal component was characterized and identified using various modern spectral analysis techniques. The results showed that the surface of silver carp scales after decalcification was smooth and clear. The pepsin had the highest peptide yield and tyrosinase-inhibiting activity (90.01% and 82.25%, respectively). The optimal enzymatic hydrolysis conditions were an enzyme dosage of 16.1%, a solid–liquid ratio of 1:15.6 and a time of 4.9 h. The proportions of hydrophobic and basic amino acids in the peptide composition were 32.15% and 13.12%, respectively. Compared with SCPs2, SCPs1 (6096.68–9513.70 Da) showed better ·OH scavenging ability, tyrosinase-inhibiting activity and moisture absorption. SCPs1 was a macromolecular fragment of type I collagen with a triple helix structure, containing three peptide sequences with the potential for tyrosinase activity inhibition (AGPPGADGQTGQRGE, SGPAGIAGPAGPRGPAGPNGPPGKD and KRGSTGEQGSTGPLGMRGPRGAA). These results show that SCPs1 is a collagen peptide product with whitening potential. [ABSTRACT FROM AUTHOR]

Collagen peptide chelated zinc (CPCZ) nanoparticles were prepared using collagen peptide hydrolysate from tilapia scales. The nano-chelating ability of collagen peptide hydrolysates treated with ten enzymes was evaluated. Among these collagen peptide hydrolysates, trypsin hydrolysate exhibited the best nano-chelating ability. The molecular weight distribution of trypsin hydrolysate that produced CPCZ nanoparticles indicated that most of the peptides were less than 1,000 Da. These small molecular peptides with excellent nanozinc-chelating ability were chelated with zinc ions to form CPCZ nanoparticles. CPCZ nanoparticles were nearly spherical with an average diameter of approximately 100 nm, and a zinc content of 13.2%. Transmission electron microscopy coupled with energy dispersive spectroscopy and Fourier transform infrared spectrometry was used to measure the physicochemical properties of the CPCZ nanoparticles. Their cytotoxicity was also estimated by BHK21 cells. Result indicated that the CPCZ nanoparticles were non-toxic to BHK-21, and such nanoparticles significantly enhanced the survival of cells. The present work suggested that CPCZ nanoparticles could be used as zinc supplementation in the food and pharmaceutical industries. [ABSTRACT FROM AUTHOR]

The interaction between collagen/collagen-like peptides and the commonly expressed immune cell receptor LAIR-1 (leukocyte-associated immunoglobulin-like receptor-1) regulates and directs immune responses throughout the body. Understanding and designing these interactions within the context of biomaterials could advance the development of materials used in medical applications. In this study, we investigate the immunomodulatory effects of biomaterials engineered to display a human collagen III-derived ligand peptide (LAIR1-LP) that targets LAIR-1. Specifically, we examine the effects of LAIR1-LP functionalized surfaces on uptake of polymeric particles and cell debris by macrophages polarized toward inflammatory or healing phenotypes. We observed that culture of macrophages on LAIR1-LP functionalized surfaces increased their uptake of PLGA micro- and nano-particles, as well as apoptotic fibroblasts, while reducing their secretion of TNFα in response to LPS/IFNγ pro-inflammatory stimulation, when compared to cells seeded on control surfaces. To investigate the role of LAIR-1 in the observed LAIR1-LP-induced effects, we used siRNA to knock down LAIR-1 expression and found that cells lacking LAIR-1 exhibited enhanced particle uptake on LAIR1-LP and control surfaces. Furthermore, analysis of gene expression showed that LAIR-1 knockdown led to increase expression of other receptors involved in cell uptake, including CD-36, SRA-1, and beta-2 integrin. Together, our study suggests that LAIR1-LP enhances macrophage uptake potentially through interactions with collagen-domain binding surface receptors, and inhibits inflammation through interaction with LAIR-1.

Catla collagen hydrolysate (CH) was fractionated by chromatography and each fraction was subjected to HA nucleation, with the resultant HA-fraction composites being scored based on the structural and functional group of the HA formed. The process was repeated till a single peptide with augmented HA nucleation capacity was obtained. The peptide (4.6 kDa), exhibited high solubility, existed in polyproline-II conformation and displayed a dynamic yet stable hierarchical self-assembling property. The 3D modelling of the peptide revealed multiple calcium and phosphate binding sites and a high propensity to self-assemble. Structural analysis of the peptide-HA crystals revealed characteristic diffraction planes of HA with mineralization following the (002) plane, retention of the self-assembled hierarchy of the peptide and intense ionic interactions between carboxyl groups and calcium. The peptide-HA composite crystals were mostly of 25–40 nm dimensions and displayed 79% mineralization, 92% crystallinity, 39.25% porosity, 12GPa Young's modulus and enhanced stability in physiological pH. Cells grown on peptide-HA depicted faster proliferation rates and higher levels of osteogenic markers. It was concluded that the prerequisite for HA nucleation by a peptide included: a conserved sequence with a unique charge topology allowing calcium chelation and its ability to form a dynamic self-assembled hierarchy for crystal propagation. [ABSTRACT FROM AUTHOR]

Increasing evidence has shown collagen hydrolysate involves a variety of bioactivities. In our previous study, multiple antiplatelet peptides containing Hyp/Pro-Gly were identified in collagen hydrolysates from Salmo salar and silver carp skin and exhibited anti-thrombosis activity without bleeding risks in vivo. However, the relationship between structure and activity remains unknown. We performed 3D-QSAR studies on 23 Hyp/Pro-Gly-containing peptides in which 13 peptides were reported before. CoMFA, Topomer CoMFA and CoMSIA analyses were used to generate the QSAR models. Topomer CoMFA analysis showed a q2 value of 0.710, an r2 value of 0.826, an r2pred value of 0.930, and the results showed that Hyp instead of Pro was more important for improving the antiplatelet activity. CoMSIA analysis showed a q2 value of 0.461, an r2 value of 0.999, and an r2pred value of 0.999. Compared with the electrostatic field and hydrogen bond donor field, the steric field, hydrophobic field and hydrogen bond receptor field have great influence on the activity of antiplatelet peptides. The predicted peptide EOGE exhibited antiplatelet activity induced by ADP, and inhibited thrombus formation (300 μmol/kg bw) without bleeding risks. Combined results of these studies indicate that OG-containing peptides had a potential to be developed into an effective specific medical food in the prevention of thrombotic diseases. [ABSTRACT FROM AUTHOR]

Type I and V collagens are the major components of fibrillogenic proteins in fish skin, and their hydrolysis products possess hyaluronidase inhibitory activity. In this study, for the first time, type I and V collagens were isolated from the skin of shortbill spearfish and striped marlin. Type I (2α1[I]α2[I]) and type V (α1[V]α3[V]α2[V]) collagens composed of distinct α-peptide chains with comparable structures were investigated using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and UV spectrophotometric chromatography. After enzymatic digestion, the collagen peptides were purified by using ultrafiltration (30 KDa) and high-performance liquid chromatography (RP-HPLC) to yield CPI-F3 and CPV-F4 fractions with strong hyaluronidase inhibition rates (42.17% and 30.09%, respectively). Based on the results of simulated gastrointestinal fluid, temperature, and pH stability assays, CPI-F3 and CPV-F4 exhibited stability in gastric fluid and showed no significant changes under the temperature range from 50 to 70 °C (p > 0.05). The results of this first research on the bioactivity of type V collagen peptides provide valuable information for the biomedical industry and show the potential for future bioactivity investigations of type V collagen and its peptides. [ABSTRACT FROM AUTHOR]

My country is both a big country of livestock breeding and a big fishery country, and it has abundant resources such as animal bones, animal skins and fish bones, fish skins and fish scales. Collagen peptides are derived products obtained by enzymatic or thermal hydrolysis of collagen. Because of its good biocompatibility, degradability, plasticity, thermal stability, flexibility, absorbency, solubility, water retention, anti-oxidation, weak antigenicity and other advantages, it is widely used in food, medical, and skin care, feed and other industries. In this paper, the raw material sources, extraction methods and applications of collagen peptides are reviewed. At the same time, feasible solutions are proposed for the problems existing in the production and manufacturing of collagen peptides, and the research direction of collagen peptides in the future is also predicted in order to provide reference for the further development of collagen peptides.

Objective: To investigate the radioprotective effect of jackfruit protein peptide and collagen peptide with pleasant mouthfeel in many bioactive peptides in 60Co γ ray-irradiated mice. Methods: Two hundred and eighty eight specific pathogen free (SPF) female BALB/c mice were randomly divided into 4 batches with 6 groups and 12 rats in each group. Each batch divided into blank control group, model control group, 2 jackfruit protein peptide intervention groups (0.20, 0.80 g/kg BW) and 2 collagen peptide intervention groups (0.53, 1.6 g/kg BW). After the 26 days of the intragastric administration, the mice except the blank control group received 60Co γ-ray whole body irradiation, and intragastric intervention continued after irradiation. The number of peripheral blood white blood cells (radiation dose 3.5 Gy, 3 and 14 days after irradiation), bone marrow DNA content and the content of 8-OhdG in serum (radiation dose 3.5 Gy, 3 days after radiation), serum hemolysin (radiation dose 1 Gy, 7 days after radiation) and superoxide dismutase (SOD) activity in blood (radiation dose 7 Gy, 7 days after radiation) were measured, respectively. Results: Compared with the model control group, the number of peripheral blood white blood cells in high dose of jackfruit peptide, and low and high dose of collagen peptide were significantly increased on 3rd day after radiation (P

Orally administered collagen peptides could contribute to antiaging by replacing the degraded extracellular matrix proteins caused by photoaging. This study aimed to evaluate the efficacy and safety of low-molecular-weight collagen peptides for treating photoaged and dry skin. In this randomized, placebo-controlled, parallel-group, double-blinded trial, we randomly assigned study participants (n = 100) to either the test product group or placebo group at a 1:1 ratio for 12 weeks. The wrinkle scale score, eye wrinkle volume, roughness parameters, such as the average maximum height of the wrinkle (Rz), arithmetic average within the total measuring length of the wrinkle (Ra), maximum profile valley depth of the wrinkle (Rv), and skin hydration, transepidermal water loss (TEWL), overall elasticity (R2), and ratio of elastic recovery to total deformation (R7) were evaluated at baseline, 6 weeks, and 12 weeks. Safety assessments with serial blood tests were also conducted. Efficacy assessments of data from 84 participants were conducted as the per-protocol analysis. After 12 weeks, the 10-grade crow's feet photo scale score, eye wrinkle volume, skin roughness parameters (Rz, Ra, and Rv), skin elasticity (R2 and R7), skin hydration, and TEWL were significantly improved in the test product group compared to the placebo group. There were no adverse events or abnormalities according to laboratory analysis associated with using the test material during the study period. This study showed that the oral supplementation of low-molecular-weight collagen peptides could improve the wrinkles, elasticity, hydration, and barrier integrity of photoaged facial skin. This clinical study was registered with the Korean Clinical Research Information Service and International Clinical Trials Registry Platform (No: KCT0006500). [ABSTRACT FROM AUTHOR]

The promising applications of collagen in tissue engineering, regenerative medicine and biomaterials have intrigued great interest in development of collagen mimetic peptides (CMPs). In past decades, the large-scale collagen structures via the self-assembly of small CMPs have been extensively explored. Moreover, CMPs entail novel strategies in order to play a critical role in the discovery of new generation biomaterials. In this regard, we herein have synthesized a CMP, (Pro-Hyp-Gly) 10 i.e. POG10. CMP has been examined in the presence of varying concentration of choline chloride (ChCl) by using various biophysical techniques such as circular dichroism (CD), UV–vis spectroscopy, fluorescence spectroscopy, Fourier transform infrared spectroscopy (FTIR) spectroscopy, differential scanning calorimetry (DSC), transmission electron microscopy (TEM) and dynamic light scattering (DLS). For the first time, we have demonstrated the use of choline chloride (ChCl) to manipulate stability and aggregation of CMP triple helices in order to delineate the factors responsible for the stability of triple helices. [Display omitted] • Synthesis and Characterization of Collagen Mimetic Peptide, POG10. • Thermal stability analysis of POG10 in the presence of choline chloride. • Differential scanning calorimetric thermographs of POG10 in the presence of choline chloride. • Choline chloride provides thermal stability to POG10. • Transmission electron micrographs of POG10 in the presence of choline chloride [ABSTRACT FROM AUTHOR]

China is rich in fishery resources. In the process of aquatic processing, most of the swim bladders are discarded as waste. It is found that the swim bladders are rich in collagen, which can be extracted after acid, protease and hot water treatment. Small molecular peptides with a variety of physiological activities and functions can be obtained after further hydrolysis of the swim bladder by protease. It is reported that fish swim bladder collagen oligopeptide has the functions of anti-oxidation, anti-aging and anti-fatigue, and fish swim bladder collagen has great potential in food, medicine and other fields. This paper summarizes the preparation and functional activity of fish swim bladder collagen and peptides at domestic and abroad in recent years, in order to provide reference for the future research of fish swim bladder collagen.

[Display omitted] • The preparation of squid cartilage type II collagen peptides (SCIIP) was studied. • SCIIP had typical collagen characteristics with 87.7 % of it below 5 kDa. • SCIIP may inhibit TLR4/MD-2 activation as predicted by molecular docking. • SCIIP alleviated the inflammation in cells by inhibiting the TLR4/NF-κB pathway. • Oral SCIIP relieved the pathological changes of osteoarthritis in rats. The promoting effects of collagen and its derivatives on bone health have been uncovered. However, the structure and effects of type II collagen peptides from squid cartilage (SCIIP) on osteoarthritis still need to be clarified. In this study, SCIIP was prepared from squid throat cartilage with pretreatment by 0.2 mol/L NaOH at a liquid–solid ratio of 10:1 for 18 h and hydrolyzation using alkaline protease and flavourzyme at 50 °C for 4 h. The structure of SCIIP was characterized as a molecular weight lower than 5 kDa (accounting for 87.7 %), a high glycine level of 35.0 %, typical FTIR and CD features of collagen peptides, and a repetitive sequence of Gly–X–Y. GP(Hyp)GPD and GPAGP(Hyp)GD were separated and identified from SCIIP, and their binding energies with TLR4/MD-2 were − 8.4 and − 8.0 kcal/mol, respectively. SCIIP effectively inhibited NO production in RAW264.7 macrophages and alleviated osteoarthritis in rats through the TLR4/NF-κB pathway. Therefore, SCIIP exhibited the potential for application as an anti-osteoarthritis supplement. [ABSTRACT FROM AUTHOR]

• Effect of peptide concentration on high internal phase emulsion (HIPE) was studied. • Effect of HIPE on the three-dimensional - printing surimi ink was studied. • Peptide concentration affected the microstructure and rheology of HIPE. • The addition of HIPE decreased the porosity of surimi. The effect of a high internal phase emulsion (HIPE) on three-dimensional-printed surimi gel inks was studied. Increasing the concentration of collagen peptide decreased the particle size of HIPE droplets and improved the viscoelasticity and stability. For example, when the collagen peptide concentration was 5 wt%, the viscoelasticity of the HIPE was high, as indicated by the presence of small and uniform particles, which formed a monolayer in the outer layer of the oil droplets to form stable a HIPE. A HIPE was used as the filling material to fill the surimi gel network, which reduced the porosity of the network. Surimi protein and peptides have dual emulsifying effects on the stabilization of oil. After adding the emulsion, the texture, gel properties and rheological properties of the surimi were reduced, and its printing adaptability was improved. This study provides new ideas for the production of surimi and its application in 3D printing. [ABSTRACT FROM AUTHOR]

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.

This study aims to isolate collagen peptides from waste sturgeon fish skin, and prepare nanoemulsions for studying their anti-diabetic and wound-healing effects in mice. Collagen peptides were extracted and purified by acetic acid with sonication, followed by two-stage hydrolysis with 0.1% pepsin and 5% flavourzyme, and ultrafiltration with 500 Da molecular weight (MW) cut-off dialysis membrane. Animal experiments were performed with collagen peptides obtained by pepsin hydrolysis (37 kDa) and pepsin plus flavourzyme hydrolysis (728 Da) as well as their nanoemulsions prepared at two different doses (100 and 300 mg/kg/day). The mean particle size of low-MW and low-dose nanoemulsion, low-MW and high-dose nanoemulsion, high-MW and low-dose nanoemulsion and high-MW and high-dose nanoemulsion was, respectively, 16.9, 15.3, 28.1 and 24.2 nm, the polydispersity index was 0.198, 0.215, 0.231 and 0.222 and zeta potential was −61.2, −63.0, −41.4 and −42.7 mV. These nanoemulsions were highly stable over a 90-day storage period (4 °C and 25 °C) and heating at 40–100 °C (0.5–2 h). Experiments in mice revealed that the low-MW and high-dose nanoemulsion was the most effective in decreasing fasting blood glucose (46.75%) and increasing wound-healing area (95.53%). Collectively, the sturgeon fish skin collagen peptide-based nanoemulsion is promising for development into a health food or wound-healing drug.

Ulcerative colitis (UC) is an inflammatory bowel disease caused by mucosal immune system disorder, which has increased steadily all over the world. Previous studies have shown that collagen peptide (CP) has various beneficial biological activities, it is not clear whether the effect of CP on UC is positive or negative. In this study, 2.5% dextran sulfate sodium (DSS) was used to establish acute colitis in mice. Our results suggested that CP supplementation (200, 400 mg/kg/day) promoted the progression of colitis, increased the expression of inflammatory factors and the infiltration of colonic lamina propria macrophages. Gut microbiota analysis showed the composition changed significantly and inflammation promoted bacteria was after CP treatment. Meanwhile, the effect of CP on macrophage polarization was further determined in Raw264.7 cell line. The results showed that CP treatment could increase the polarization of M1 macrophages and promote the expression of inflammatory factors. In conclusion, our results showed that CP treatment could disrupt the gut microbiota of host, promote macrophage activation and aggravate DSS-induced colitis. This may suggest that patients with intestinal inflammation should not take marine derived CP.

In biology, collagen-biomaterial regulates several signaling mechanisms of bone and immune cells involved in tissue repair and any imbalance in collagen turnover may affect the homeostasis of cells, becoming a major cause of several complications. In this case, the administration of oral collagen may play a potential role in returning cells to their normal function. For several decades, the beneficial effects of collagen have been explored widely, and thus many commercial products are available in cosmetics, food, and biomedical fields. For instance, collagen-based-products have been widely used to treat the complications of cartilage-related-disorders. Many researchers are reporting the anti-arthritogenic properties of collagen-based materials. In contrast, collagen, especially type-II collagen (CII), has been widely used to induce arthritis by immunization in an animal-model with or without adjuvants, and the potentially immunogenic-properties of collagen have been continuously reported for a long time. Additionally, the immune tolerance of collagen is mainly regulated by the T-lymphocytes and B-cells. This controversial hypothesis is getting more and more evidence nowadays from both sides to support its mechanism. Therefore, this review links the gap between the arthritogenic and anti-arthritogenic effects of collagen and explored the actual mechanism to understand the fundamental concept of collagen in arthritis. Accordingly, this review opens-up several unrevealed scientific knots of collagen and arthritis and helps the researchers understand the potential use of collagen in therapeutic applications. [ABSTRACT FROM AUTHOR]

Introduction: We examined the effect of 5.0 g/day of collagen peptide (CP) or collagen peptide fermented with Aspergillus sojae (FCP) on skin pigmentation in healthy participants. Methods: In this randomized, double-blind, placebo-controlled study, 44 men and women aged 25–63 years were placed into three groups by stratified random allocation and treated with CP, FCP, or placebo (PL) at 5.0 g/day for 3 months. Their skin condition was measured monthly from baseline to 3 months of intake. Results: No adverse events were identified in any group. The CP group showed a significant reduction in pigmented patches and redness after 1 and 3 months of intake, respectively. In the FCP group, pigmented macules were significantly reduced after 1 month, and pigmented patches after 2 months. Both the all-ages analysis and the hierarchical analysis below 55 years old yielded similar results. Conclusion: Intake of 5.0 g/day of FCP for 3 months is safe. CP and FCP intake is useful for suppressing pigmentation. In addition, CP intake may be useful for reducing redness. These results suggest a new beneficial effect on the skin of CP supplementation. Trial Registration: UMIN clinical trials registry system, UMIN000040736. [ABSTRACT FROM AUTHOR]

Abstract Effective and ecofriendly converting biomass to chemicals is important for sustainable engineering based on the foreseeable shortage of fossil resources. Undecylprodigiosin (UP) is a promising antibiotic, but the direct feeding of pure precursor amino acids makes it costly for large-scale production. Here, collagen peptide (CP), a renewable animal-derived biomass contains abundant precursor amino acids of UP. CP can act as carbon and nitrogen source for the growth of Streptomyces coelicolor CGMCC 4.7172. The plant biomasses including soybean meal, wheat bran, and malt extract were unsuitable for UP prodution. However, 365.40 µg/L UP was detected after 24 h in the media containing CP, and its highest concentration reached 1198.01 µg/L. UP was also detected in the media containing meat hydrolysates of domestic animals, but its initial production time was delayed, and final concentration was lower than that in the medium containing CP only. Compared the fermentation performances of CP and other proteins, CP has a special superiority for UP production. These results revealed that UP biosynthesis may be dependent on amino acid availability of substrates and CP is beneficial for UP production because of its specific amino acid composition. Graphical abstract

This study investigated the effect of ultrasound assisted chicken cartilage collagen peptide (CP) treatment on the storage quality of chicken breast meat. There were five meat groups at 4 °C for 60 min as follows: untreatment (Control), immersing in deionized water (DW), ultrasound treatment in DW (UDW), immersing in CP (0.15 g/100 mL) solution and immersing in ultrasound combined with CP (UCP). The results showed that the drip and cooking loss of meat decreased significantly in UCP at 4 and −18 °C with the extension of storage time. A large amount of non-flowing water transformed into free water in the 4 °C for 5 d, and the smallest degree of water migration was observed at −18 °C in UCP. The texture parameters of UCP group were significantly improved, especially for decreased hardness and increased elasticity. Furthermore, there had no significant effect on the color of chicken breast.

Objective: Collagen was extracted from the skin of Micropterus salmoides and used to explore the effect of enzyme types on the antioxidant activity of collagen peptides. Methods: Four kinds of enzymes were used, namely alkaline protease, neutral protease, papain and trypsin. The enzymatic hydrolysis of collagen Alkaline protease enzymatically hydrolyze collagen peptide （APP）, Neutral protease enzymatically hydrolyze collagen peptide （NPP）, Papain enzymatically hydrolyze collagen peptide（PP）, Trypsin hydrolysis of collagen peptide（TP）, were obtained and compared their total antioxidant activity, including reducing activity, DPPH, ·OH and O-2·free radical scavenging ability, ferrous ion chelating ability and lipid Oxidation inhibitory activity. Results: Four kinds of proteases enzymatically hydrolyze collagen peptides all have antioxidant activity, and the antioxidant capacity was positively correlated with the concentration of collagen peptides. Among them, APP has the best antioxidant activity. The total antioxidant activity and reducing activity respectively were 1.725 and 0.958, and the scavenging rates for DPPH and O-2·radical respectively were 56.35% and 38.41%, respectively. Conclusion: The collagen peptides hydrolyzed by alkaline protease have better antioxidant activity.