Calcium-chelating peptides from rabbit bone collagen:characterization,identification and mechanism elucidation

This study aimed to characterize and identify calcium-chelating peptides from rabbit bone collagen and explore the underlying chelating mechanism.Collagen peptides and calcium were extracted from rabbit bone by instant ejection steam explosion(ICSE)combined with enzymatic hydrolysis,followed by chelation reaction to prepare rabbit bone peptide-calcium chelate(RBCP-Ca).The chelating sites were further analyzed by liquid chromatography-tandem mass(LC-MS/MS)spectrometry while the chelating mechanism and binding modes were investigated.The structural characterization revealed that RBCP successfully chelated with calcium ions.Furthermore,LC-MS/MS analysis indicated that the binding sites included both acidic amino acids(Asp and Glu)and basic amino acids(Lys and Arg),Interestingly,three binding modes,namely Inter-Linking,Loop-Linking and Mono-Linking were for the first time found,while Inter-Linking mode accounted for the highest proportion(75.1%),suggesting that chelation of calcium ions frequently occurred between two peptides.Overall,this study provides a theoretical basis for the elucidation of chelation mechanism of calcium-chelating peptides.

Anti-skin aging effects and bioavailability of collagen tripeptide and elastin peptide formulations in young and middle-aged women

Background:Collagen peptides(CP),including tripeptides and elastin peptides(EP),are known for their in vitro and in vivo anti-skin aging effects.Despite positive results in animal models,the combination effects of CP and EP and the bioavailability of CP in human studies,particularly in young and middle-aged women,remain underexplored.Objective:To evaluate the effects of an orally administered collagen drink combining CP and EP on the skin health of young and middle-aged women.Materials and Methods:A single-center,randomized,double-blind,parallel-controlled trial was conducted,utilizing the WONDERLABR fish collagen tripeptide beverage.Participants consumed the drink over an 8-week period.Results:Compared to the placebo group,the collagen drink group showed significant improvements in skin hydration(39.19%increase),transepidermal water loss(33.45%decrease),skin elasticity(25.37%increase),dermal collagen content(21.64%increase),pore size(7.94%decrease),wrinkle length(18.09%decrease),skin smoothness(2.85%improvement),and skin roughness(15.32%decrease).Overall pore volume decreased by 60%,and visual assessments indicated a decrease in skin luminosity by 15.20%and smoothness index by 22.55%.Mass spectrometry demonstrated a significant increase in collagen efficacy components,including blood pH and GPH levels(P<0.05).Conclusion:The study confirmed the combination nourishing and anti-skin aging effects of EP and CP on the skin of young and middle-aged women,demonstrating significant improvements in various skin parameters and good bioavailability of collagen peptides.

Progress in the extraction and application of collagen peptides

Collagen peptide is the product of complete hydrolysis of collagen,which has a relatively small molecular weight and is more easily absorbed than proteins and amino acids.Collagen peptide not only has unique nutritional value,but also has certain physiological functions,which makes it has great potential value in various fields,so it has set off a wave of research on collagen peptide in the biological world.This paper describes the sources and extraction methods of collagen peptides,and describes the research progress and application of collagen peptides in the medical,food,material and skin care industries according to their physiological functions,which will provide new ideas for the future research of collagen peptides.

Effects of Collagen Peptide from Cyanea nozakii on Mouse Immune Function

[Objective ] The study aimed to provide a theoretical basis for the clinical application of collagen peptide from Cyanea nozakii. [ Method] After acute toxicity test on mice, collagen peptide from C. nozakii were given to mice by continuous intragastric administration for 30 d at the doses of 25, 50, 100 mg/kg, and then the phagocytosis of macrophage, delayed type hypersensitivity （DTH） and serum hemolysin level were determined. [ Result] Collagen peptide from C. nozakii was atoxic or low toxic, and the three immune indices of experimental groups were signifi- canUy higher than those of the control group （treated with same volume of normal saline） at 0.05 or 0.01 level. E Conclusion] Collagen peptide from C. nozakii has a certain immunopotentiation.

Effect of Marine Collagen Peptides on Markers of Metabolic Nuclear Receptors in Type 2 Diabetic Patients with/without Hypertension

Objective To explore Effects of marine collagen peptides （MCPs） on markers of metablic nuclear receptors, i.e peroxisome proliferator-activated receptor （PPARs）, liver X receptor （LXRs） and farnesoid X receptor （FXRs） in type 2 diabetic patients with/without hypertension. Method Study population consisted of 200 type 2 diabetic patients with/without hypertension and 50 healthy subjects, all of whom were randomly assigned to MCPs-treated diabetics （n=50）, placebo-treated diabetics （n=50）, MCPs-treated diabetics with hypertension （n=50）, placebo-treated diabetics with hypertension （n=50）, and healthy controls （n=50）. MCPs or placebo （water-soluble starch） were given daily before breakfast and bedtime over three months. Levels of free fatty acid, cytochrome P450, leptin, resistin, adiponectin, bradykinin, NO, and Prostacyclin were determined before intervention, and 1.5 months, and 3 months after intervention. Hypoglycemia and the endpoint events during the study were recorded and compared among the study groups. Result At the end of the study period, MCPs-treated patients showed marked improvement compared with patients receiving placebo. The protection exerted by MCPs seemed more profound in diabetics than in diabetics with hypertension. In particular, after MCPs intervention, levels of free fatty acid, hs-CRP, resistin, Prostacyclin decreased significantly in diabetics and tended to decrease in diabetic and hypertensive patients whereas levels of cytochrome P450, leptin, NO tended to decrease in diabetics with/without hypertension. Meanwhile, levels of adiponectin and bradykinin rose markedly in diabetics following MCPs administration. Conclusion MCPs could offer protection against diabetes and hypertension by affecting levels of molecules involved in diabetic and hypertensive pathogenesis. Regulation on metabolic nuclear receptors by MCPs may be the possible underlying mechanism for its observed effects in the study. Further study into its action may shed light on development of new drugs based on bioactive peptides from marine sources.

Comparative Study on the Antioxidant Activity of Peptides from Pearl Oyster(Pinctada martensii) Mantle Type V Collagen and Tilapia(Oreochromis niloticus) Scale Type Ⅰ Collagen

In this study, Pearl oyster mantle type V collagen(POMC) and tilapia scale type I collagen(TSC) were extracted and hydrolyzed by various proteases in order to obtain peptides. The antioxidant activity of the peptides was investigated by DPPH, hydroxyl radical scavenging experiments and a dynamic digestion model in vitro. The results show that there are significant differences in amino acid composition between POMC and TSC. The collagen peptides obtained from pearl oyster mantle(POMCP) by treating with alkaline protease exhibited higher antioxidant activity than that from tilapia scale(TSCP) treated with papaya protease, and both of them showed greater DPPH and hydroxyl radical scavenging activity than other peptides. After being separated via Sephadex G-25 chromatography, the M1 fraction isolated from POMCP, and the S1 fraction from TSCP with which both had higher molecular weights showed the strongest antioxidant activity than other fractions, and the M1 fraction exhibited stronger antioxidant activity than the S1 fraction in scavenging free-radicals and protecting cells from the oxidation damage. Furthermore, after treating the dynamic digestion system model in vitro, the DPPH and hydroxyl radical scavenging activity of the M1 fraction increased slightly. These results suggest that POMCP exhibits stronger antioxidant activity than TSCP, which means that PMOP may be a good candidate to be a potential natural antioxidant in the food-processing industry.

Recent progress in preventive effect of collagen peptides on photoaging skin and action mechanism

Ultraviolet(UV)-induced photoaging skin has become an urgent issue.The functional foods and cosmetics aiming to improve skin photoaging are developing rapidly,and the demand is gradually increasing year by year.Collagen peptides have been proven to display diverse physiological activities,such as excellent moisture retention activity,hygroscopicity,tyrosinase inhibitory activity and antioxidant activity,which indicates that they have great potential in amelioration of UV-induced photoaging.The main objective of this article is to recap the main mechanisms to improve photoaging skin by collagen peptides and their physiological activities in photo-protection.Furthermore,the extraction and structural characteristics of collagen peptides are overviewed.More importantly,some clinical trials on the beneficial effect on skin of collagen peptides are also discussed.In addition,prospects and challenges of collagen peptides are emphatically elucidated in this review.This article implies that collagen peptides have great potential as an effective ingredient in food and cosmetics industry with a wide application prospect.

The Effectiveness of Specific Collagen Peptides on Osteoarthritis in Dogs-Impact on Metabolic Processes in Canine Chondrocytes

In clinical trials over the past decade, the beneficial effect of orally administered collagen peptides in osteoarthritic dogs has been clearly demonstrated [1] [2] [3]. Although a statistically significant improvement in the lameness and vitality of dogs in general has been documented, the mode of action of the collagen peptide treatment is still under discussion. A previous study [3] indicated that the reduction in lameness and increased mobility in dogs after collagen peptide treatment were associated with a statistically significantly lowered plasma content of MMP-3, which is involved in collagen degradation. In addition, the content of the MMP-antagonist TIMP-1 increased slightly after collagen peptide supplementation, suggesting a direct impact on the cartilage metabolism, particularly on the decrease of extracellular matrix degradation. Based on these findings, the impact of specific collagen peptides (PETA-GILE?) on cartilage metabolism was tested in canine chondrocytes in the current investigation. In addition to the biosynthesis of various matrix molecules (type II collagen, aggrecan and elastin), the RNA profile of inflammatory cytokines and degenerative matrix molecules was investigated. The results showed clearly that the supplementation of specific collagen peptides reduced catabolic processes, as indicated by a statistically significant decrease in inflammatory cytokines and proteases in canine chondrocytes compared with untreated control experiments. In addition, a statistically significantly enhanced biosynthesis of type II collagen, elastin, and aggrecan was observed. Hence, the current data supports the suggested anti-inflammatory effect of specific collagen peptides, but also clearly demonstrates a pronounced stimulatory impact on matrix molecule synthesis. A combination of both observed effects might help to explain the previously reported clinical improvements after collagen peptide supplementation. Furthermore, the beneficial effect of the specific collagen peptides was also confirmed in case reports on osteoarthritic dogs that demonstrated decreased lameness and increased vitality in the affected animals after PETAGILE treatment.

Spectrofluorometric Assays of Human Collagenase Activity Using Native Collagen and Acetyl-Peptide Substrates

A selective, sensitive, and convenient assay for human collagenase is required because of its implication in diseases such as rheumatoid arthritis, osteoarthritis, and tumors. Here, a novel assay for human collagenase activity is described in which enzymatic degradation of native collagen or acetyl peptide is determined by using a fluorogenic reaction for oligopeptides. The oligopeptides are quantified spectrofluorometrically with either 3,4-dihydroxyphenylacetic acid or 1,2-dihydroxybenzen reaction in the presence of sodium periodate and sodium borate (pH 7 - 8). These reactions can selectively convert N-terminal Gly-containing oligopeptides and N-terminal Ile-containing oligopeptides to fluorescence (FL) compounds, respectively, but not proteins, acetyl peptides or amino acids. Under optimized conditions using 1.65 μM collagen IV or 1.5 mM Ac-GPQGI- AGQ as substrates, this assay exhibits a proportional relationship between FL intensities and human collagenase-3 (MMP-13) concentrations. It can assay endogenous collagenase activities in several biological samples, such as cultured human cells and cheek tissue.

Review on marine collagen peptides induce cancer cell apoptosis,necrosis,and autophagy by reducing oxidized free radicals

Marine collagen peptides(MCPs)are natural products prepared by hydrolyzing marine collagen protein through a variety of chemical methods or enzymes.MCPs have a range of structures and biological activities and are widely present in marine species.MCPs also have a small molecular weight,are easily modified,and absorbed by the body.These properties have attracted great interest from researchers studying antioxidant,anti-tumor,and anti-aging activities.MCPs of specific molecular weights have significant anti-tumor activity and no toxic side effects.Thus,MCPs have the potential use as anti-cancer adjuvant drugs.Free radicals produced by oxidation are closely related to human aging,cancer,arteriosclerosis,and other diseases,but their relationship with cancer is not well known.In this review,we focus on the antioxidant properties of MCPs in the treatment of cancer,highlighting their antioxidant molecular structure and potential for clinical practice.

Active Peptides and Motifs within Collagen and Other ECM Proteins

Collagens are the most abundant proteins in mammals and form an extracellular matrix (ECM) with other components as the structural support of muscle, skin, corneas and blood vessels etc. Other than providing structural support, the ECM exhibits active communication with cells and influences many cellular processes including migration, wound healing, differentiation and cancer metastasis. Though collagen proteins contain highly repetitive primary sequences and defined tertiary structures, more and more studies have shown that many short peptides/motifs within collagen proteins play key roles in various biological processes. These short sequences are effective within triple helical structures or independently as stand-alone molecules resulting from proteolytic degradation. Besides endogenous ECM-derived peptides, many more functional peptides have been produced by tissue processing, chemical synthesis, and recombinant protein production. In this review, we summarize different peptides/motifs identified in collagen and other ECM proteins and discuss their potential for medical, personal care, and cosmetics applications.

Study on the Reparative Effect of Peptide RW3 Binding Active Collagen after Photoelectric Skincare

The photoelectric microneedle treatment instrument is also widely used due to the rapid development of medical cosmetology in China in recent years. It also causes a lot of skin discomfort after the consumers carry out such projects. This study, which combines small molecule active peptides (RW3) and active collagens and imitates the photoelectric treatment through in vitro and in vivo experiment, finds that small molecule active peptides (RW3) and active collagens have different improvement effects on cell proliferation, migration, anti-UV damage, inhibition of ear swelling and inflammation in mice, repair of UV damage and skin damage caused by microneedles. .

Structural, thermal and enzymatic analysis of naturally occurring and D-amino acid substituted peptides

Designing of new peptide materials for biomedical and protein engineering applications are important. In the present work an attempt has been made to study the effect of D-Leu in collagen like tetra peptide on the structure and stability of peptide against enzymes and results are compared with its chiral counterpart L-form. Effect of replacement of L-Leu in Leu-Gly-Pro-Ala tetra peptide with D-Leu on structure has been studied using circular dichroic spectroscopy (CD). Our findings suggest that, D-Leu substitution leads to conformational changes in Leu-Gly-Pro-Ala secondary structure from β-sheet to turns. L → D-Leu Configurational changes in Leu-Gly-Pro-Ala owes to enhanced thermal stability which has been substantiated through CD and differential scanning calorimetry. Change in chirality of the leucine inhibits collagenolytic activity, which enables to design selective inhibition of proteases with greater specificity.

软骨胶原蛋白肽的制备、特性及其成骨细胞增殖活性研究

为充分利用鲨鱼软骨资源,本研究以成骨细胞增殖率为指标,在优化促成骨细胞增殖胶原蛋白肽酶解工艺的基础上,分析酶解物的相对分子质量、氨基酸组成及稳定性等。结果表明,酸性蛋白酶为最优蛋白酶,且在酶添加量5 100 U·g^(-1)、料液比1∶50(g·mL^(-1))、酶解时间4.14 h和温度55℃条件下,得率为91.23%。所制酶解物促成骨细胞增殖率与水解度分别为141.23%与25.03%;鲨鱼软骨胶原蛋白肽具有一定的稳定性且对紫外光不敏感,适当加热可以提升其促成骨细胞增殖率,但温度过高会使增殖率显著下降;经胃肠模拟消化后,酶解物促成骨细胞增殖率显著下降;所制酶解物以疏水氨基酸为主,其蛋白肽分子量一般小于3 kDa,具有促进成骨细胞增殖、分化及矿化作用,以浓度1.0 mg·mL^(-1)时效果较佳。本研究可为鲨鱼资源精深加工和高值化利用提供一定理论依据。

Matrix metalloproteinase 2 degrades collagen I to regulate ovarian development by association with an insulin-like peptide

The ovary generally undergoes tissue remodeling during larval to pupal transition,which includes membrane degeneration and ovariole growth.At the same time,the hormones produced by insects significantly change during metamorphosis.However,the regulatory mechanism for ovarian development and hormones is not fully understood in insects.Herein,we found that matrix metalloproteinase 2(MMP2)was highly expressed in the ovarian capsules and ovarioles,and the development was abnormal after knocking out MMP2 in Bombyx mori.The process of abnormal degradation of collagen I due to MMP2 deletion,which resulted in abnormal development of ovarioles and eggs,was analyzed in detail.The proteomics of ovaries in the MMP2-knock out and wild type strains showed a critically significant difference in the expression of a protein,insulin-like peptide(ILP).Additional analysis revealed significant alteration of ILP during ovarian development,and abnormal expression of ILP significantly affected ovarian development in vivo and MMP2 expression in vitro and in vivo.These results showed that MMP2 regulation of ovarian tissue remodeling is closely related to ILP expression.Our study provides new insights into the regulatory mechanism of MMP2 and ovarian development in B.mori.

Antioxidant and anti-HepG2 cell activities of a novel bioactive peptide from cowhide collagen in vitro

In the present study,the antioxidant and anti-human liver cancer(HepG2)cells effects of bioactive peptides from cowhide collagen(BPCC)were evaluated.BPCC exhibited significant scavenging effect on l,1-diphenyl-2-picrylhydrazyl(DPPH)radicals((60.09±3.51)%),2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS)radicals((77.40±3.10)%)and hydroxyl radicals((56.00±2.30)%)as well as strong reducing power(0.320士0.025).Meanwhile,BPCC effectively protected biomacromolecules including proteins,lipids and DNA from oxidative damage induced by Cu^(2+)H_(2)O_(2)and 2,2'-azobis(2-methylpropionamidine)dihydrochloride(AAPH).Moreover,BPCC significantly inhibited cell viability of HepG2 cells in a dose-dependent manner with an estimated IC_(50)of 7.61 mg/mL.The results of 4',6-diamidino-2-phenylindole(DAPI)and acridine:orange/ethidium bromide(AO/EB)staining demonstrated the apoptotic morphological changes and cell mediated death in BPCC treated HepG2 cells.In addition,BPCC induced decrease of mitochondrial membrane potential(MMP)in HepG2 cells.Therefore,the present finding proved that BPCC encompasses significant antioxidant activity and anticancer property on HepG2 cells and can be used as alternative food antioxidants for cancer prevention benefits.

Chicken collagen hydrolysates differentially mediate anti-inflammatory activity and type I collagen synthesis on human dermal fibroblasts

Collagen is a major extracellular matrix protein.Given the potential anti-inflammatory and antioxidant profiles of these bioactive compounds,there has been increasing interest in using collagen derived peptides and peptide-rich collagen hydrolysates for skin health,due to their immunomodulatory,antioxidant and proliferative effects on dermal fibroblasts.However,all hydrolysates are not equally effective in exerting the beneficial effects;hence,further research is needed to determine the factors that improve the therapeutic applicability of such preparations.We used different enzymatic conditions to generate a number of different collagen hydrolysates with distinct peptide profiles.We found that the use of two rather than one enzyme for hydrolysis generates a greater abundance of low molecular weight peptides with consequent improvement in bioactive properties.Testing these hydrolysates on human dermal fibroblasts showed distinct actions on inflammatory changes,oxidative stress,type I collagen synthesis and cellular proliferation.Our findings suggest that different enzymatic conditions affect the peptide profile of hydrolysates and differentially regulate their biological activities and potential protective responses on dermal fibroblasts.

The Antioxidant Effects of Complexes of Tilapia Fish Skin Collagen and Different Marine Oligosaccharides

An excess of reactive oxygen species（ROS）leads to a variety of chronic health problems.As potent antioxidants,marine bioactive extracts containing oligosaccharides and peptides have been extensively studied.Recently,there is a growing interest in protein-polysaccharide complexes because of their potential uses in pharmaceutical and food industries.However,only few studies are available on the antioxidant activities of such complexes,in terms of their ROS scavenging capability.In this study,we combined and superoxide radicals,and to evaluate the influences on the activities of superoxide dismutase（SOD）,glutathione peroxidase（GSH-Px）and the level of malondialdehyde（MDA）in UV-induced photoaging models.The results indicated that the antioxidant activities of all the complexes were stronger than those of their individual components.Among the 11 complexes tested,two complexes,namely MA1000＋CP and κ-ca3000＋CP,turned out to be highly effective antioxidants.Although the detailed mechanisms of this improved scavenging ability are not fully understood,this work provides insights into the design of highly efficient peptide-oligosaccharide complexes for potential applications in pharmaceutical,cosmetics and food industries.

Supplementation with yak (Bos grunniens) bone collagen hydrolysate altered the structure of gut microbiota and elevated short-chain fatty acid production in mice

In this study, yak bone collagen hydrolysate(YBCH)was produced by mixed proteases and provided to standard-diet mice at a different dose(low dose(LD), medium dose(MD), and high dose(HD))to investigate its effects on the composition of gut microbiota and short-chain fatty acids(SCFA)production. It was found that YBCH was mainly composed of small molecular peptides whose molecular weight below 2 000 Da. Notably, supplementation with different doses of YBCH could significantly downregulate the ratio of Firmicutes to Bacteroidetes in the fecal microbiota. At the family level, the Lachnospiraceae abundance was significantly reduced in the YBCH gavage groups(mean reduction ratio 41.7 %, 35.2%, and 36.4% for LD, MD, and HD group, respectively). The predicted functions of gut microbes in the MD group were significantly increased at “lipid metabolism” and “glycan biosynthesis and metabolism”. Moreover, the SCFA production in the YBCH groups was elevated. Especially, the concentration of acetic acid, propionic acid, and butyric acid in the MD group was separately increased 79.7%, 89.2%, and 78.8% than that in the NC group. These results indicated that YBCH might be applied in the development of functional food for intestinal microecological regulation.

Beauty from within: A Review of the Science behind Yuliv^TMCollagen Drink: An Anti-Aging Nutraceutical

The use of nutraceuticals to improve skin properties and decelerate skin aging has been gaining attention among dermatologists, over the last years. In this article, we are presenting the theoretical scientific support for YulivTM Collagen Drink, a liquid supplement containing bovine type I collagen peptides, ascorbic acid and Camellia sinensis (green tea) extract and its benefits on the skin. The available literature shows that the ingredients contained in the supplement have the potential to improve of skin hydration, dermis collagen density, and decrease the fragmentation of the dermal collagen network—and therefore reduce wrinkles and sagging and improving elasticity. Additionally, other health benefits could also be observed, such as protection against oxidative stress, contribution to the normal function of the immune system and reducing tiredness and fatigue, and reduction of skin inflammation, improvement of elasticity and prevention of oxidation. For those benefits to be visible, it is likely that continuous use of at least 4 weeks is needed.