Effect of Orally Administered Collagen Peptides from Bovine Bone on Skin Aging in Chronologically Aged Mice

Comprehensive review on collagen extraction from food by-products and waste as a value-added material

The consumption of animal products has witnessed a significant increase over the years, leading to a growing need for industries to adopt strict waste control measures to mitigate environmental impacts. The disposal of animal waste in landfill can result in diverse and potentially hazardous decomposition by-products. Animal by-products, derived from meat, poultry, seafood and fish industries, offer a substantial raw material source for collagen and gelatin production due to their high protein content. Collagen, being a major protein component of animal tissues, represents an abundant resource that finds application in various chemical and material industries. The demand for collagen-based products continues to grow, yet the availability of primary material remains limited and insufficient to meet projected needs. Consequently, repurposing waste materials that contain collagen provides an opportunity to meet this need while at the same time minimizing the amount of waste that is dumped. This review examines the potential to extract value from the collagen content present in animal-derived waste and by-products. It provides a systematic evaluation of different species groups and discusses various approaches for processing and fabricating repurposed collagen. This review specifically focuses on collagen-based research, encompassing an examination of its physical and chemical properties, as well as the potential for chemical modifications. We have detailed how the research and knowledge built on collagen structure and function will drive the new initiatives that will lead to the development of new products and opportunities in the future. Additionally, it highlights emerging approaches for extracting high-quality protein from waste and discusses efforts to fabricate collagen-based materials leading to the development of new and original products within the chemical, biomedical and physical science-based industries.

Fermented Fish Collagen Attenuates Melanogenesis via Decreasing UV-Induced Oxidative Stress

Excessive melanogenesis leads to hyperpigmentation-related cosmetic problems. UV exposure increases oxidative stress, which promotes melanogenesis-related signal pathways such as the PKA, microphthalmia-associated transcription factor (MITF), tyrosinase (TYR), tyrosinase-related protein-1 (TRP1), and tyrosinase-related protein-2 (TRP2) pathways. Glycine is a source of endogenous antioxidants, including glutathione. Fermented fish collagen (FC) contains glycine; thus, we evaluated the effect of FC on decreasing melanogenesis via decreasing oxidative stress. The glycine receptor (GlyR) and glycine transporter-1 (GlyT1) levels were decreased in UV-irradiated keratinocytes; however, the expression levels of these proteins increased upon treatment with FC. The FC decreased oxidative stress, as indicated by the decreasing expression of NOX1/2/4, increased expression of GSH/GSSG, increased SOD activity, and decreased 8-OHdG expression in UV-irradiated keratinocytes. Administration of conditioned media from FC-treated keratinocytes to melanocytes led to decreased p38, PKC, MITF, TRP1, and TRP2 expression. These changes induced by the FC were also observed in UV-irradiated animal skin. FC treatment increased the expression of GlyR and GlyT, which was accompanied by decreased oxidative stress in the UV-irradiated skin. Moreover, the FC negatively regulated the melanogenesis signaling pathways, leading to decreased melanin content in the UV-irradiated skin. In conclusion, FC decreased UV-induced oxidative stress and melanogenesis in melanocytes and animal skin. FC could be used in the treatment of UV-induced hyperpigmentation problems.

Effects of Oral Collagen for Skin Anti-Aging: A Systematic Review and Meta-Analysis

This paper presents a systematic review and meta-analysis of 26 randomized controlled trials (RCTs) involving 1721 patients to assess the effects of hydrolyzed collagen (HC) supplementation on skin hydration and elasticity. The results showed that HC supplementation significantly improved skin hydration (test for overall effect: Z = 4.94, p < 0.00001) and elasticity (test for overall effect: Z = 4.49, p < 0.00001) compared to the placebo group. Subgroup analyses demonstrated that the effects of HC supplementation on skin hydration varied based on the source of collagen and the duration of supplementation. However, there were no significant differences in the effects of different sources (p = 0.21) of collagen or corresponding measurements (p = 0.06) on skin elasticity. The study also identified several biases in the included RCTs. Overall, the findings suggest that HC supplementation can have positive effects on skin health, but further large-scale randomized control trials are necessary to confirm these findings.

Probiotic Bacteria from Human Milk Can Alleviate Oral Bovine Casein Sensitization in Juvenile Wistar Rats

This study aims to see if probiotic bacteria from human milk could ameliorate oral cow's milk sensitization. The probiotic potential of the SL42 strain isolated from the milk of a healthy young mother was first determined. Rats were then randomly gavaged with cow's milk casein without an adjuvant or assigned to the control group. Each group was further subdivided into three groups, with each receiving only Limosilactobacillus reuteri DSM 17938, SL42, or a phosphate-buffered saline solution. Body weight, temperature, eosinophils, serum milk casein-specific IgE (CAS-IgE), histamine, and serum S100A8/A9 and inflammatory cytokine concentrations were measured. The animals were sacrificed after 59 days; histological sections were prepared, and the spleen or thymus weights, as well as the diversity of the gut microbiota, were measured. On days 1 and 59, SL42 abridged systemic allergic responses to casein by dropping histamine levels (25.7%), CAS-specific IgE levels (53.6%), eosinophil numbers (17%), S100A8/9 (18.7%), and cytokine concentrations (25.4-48.5%). Analyses of histological sections of the jejunum confirmed the protective effect of probiotic bacteria in the CAS-challenged groups. Lactic acid bacteria and Clostridia species were also increased in all probiotic-treated groups. These findings suggest that probiotics derived from human milk could be used to alleviate cow's milk casein allergy.

Food Peptides for the Nutricosmetic Industry

In recent years, numerous reports have described bioactive peptides (biopeptides)/hydrolysates produced from various food sources. Biopeptides are considered interesting for industrial application since they show numerous functional properties (e.g., anti-aging, antioxidant, anti-inflammatory, and antimicrobial properties) and technological properties (e.g., solubility, emulsifying, and foaming). Moreover, they have fewer side effects than synthetic drugs. Nevertheless, some challenges must be overcome before their administration via the oral route. The gastric, pancreatic, and small intestinal enzymes and acidic stomach conditions can affect their bioavailability and the levels that can reach the site of action. Some delivery systems have been studied to avoid these problems (e.g., microemulsions, liposomes, solid lipid particles). This paper summarizes the results of studies conducted on biopeptides isolated from plants, marine organisms, animals, and biowaste by-products, discusses their potential application in the nutricosmetic industry, and considers potential delivery systems that could maintain their bioactivity. Our results show that food peptides are environmentally sustainable products that can be used as antioxidant, antimicrobial, anti-aging, and anti-inflammatory agents in nutricosmetic formulations. Biopeptide production from biowaste requires expertise in analytical procedures and good manufacturing practice. It is hoped that new analytical procedures can be developed to simplify large-scale production and that the authorities adopt and regulate use of appropriate testing standards to guarantee the population's safety.

Intradermally delivered mRNA-encapsulating extracellular vesicles for collagen-replacement therapy

The success of messenger RNA therapeutics largely depends on the availability of delivery systems that enable the safe, effective and stable translation of genetic material into functional proteins. Here we show that extracellular vesicles (EVs) produced via cellular nanoporation from human dermal fibroblasts, and encapsulating mRNA encoding for extracellular-matrix α1 type-I collagen (COL1A1) induced the formation of collagen-protein grafts and reduced wrinkle formation in the collagen-depleted dermal tissue of mice with photoaged skin. We also show that the intradermal delivery of the mRNA-loaded EVs via a microneedle array led to the prolonged and more uniform synthesis and replacement of collagen in the dermis of the animals. The intradermal delivery of EV-based COL1A1 mRNA may make for an effective protein-replacement therapy for the treatment of photoaged skin.

Evaluating the Degradation Process of Collagen Sponge and Acellular Matrix Implants In Vivo Using the Standardized HPLC-MS/MS Method

The purpose of this study was to establish a collagen determination method based on an isotope-labeled collagen peptide as an internal reference via high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS), and using the established method to evaluate the degradation process of collagen-based implants in vivo. The specific peptide (GPAGPQGPR) of bovine type I collagen was identified with an Orbitrap mass spectrometer. Then, the quantification method based on the peptide detection with HPLC-MS/MS was established and validated, and then further used to analyze the degradation trend of the collagen sponge and acellular matrix (ACM) in vivo at 2, 4, 6, 8, 12, 16, and 18 weeks after implantation. The results indicate that the relative standard deviation (RSD) of the detection precision and repeatability of the peptide-based HPLC-MS/MS quantification method were 3.55% and 0.63%, respectively. The limitations of quantification and detection were 2.05 × 10−3 μg/mL and 1.12 × 10−3 μg/mL, respectively. The collagen sponge and ACM were completely degraded at 10 weeks and 18 weeks, respectively. Conclusion: A specific peptide (GPAGPQGPR) of bovine type I collagen was identified with an Orbitrap mass spectrometer, and a standardized HPLC-MS/MS-based internal reference method for the quantification of bovine type I collagen was established. The method can be used for the analysis of the degradation of collagen-based implants in vivo.

Hot spring bathing accelerates wound healing and enhances heat retention effect in guinea pigs

This study aimed to demonstrate the effects of hot springs on wound healing and heat retention by performing comparative experiments with tap water. The hot spring water used in this study was from an alkaline hot spring that was rich in sodium and chloride ions and exhibited high reducibility. Guinea pigs were divided into a hot spring bathing group and a tap water bathing group, and a bathing test was conducted for eight consecutive days. A comparison of the plasma amino acid composition between the two groups after the bathing test revealed differences in the concentrations of several amino acids associated with wound healing. Image analysis demonstrated that wounds made on the abdominal skin of guinea pigs were significantly contracted by hot spring bathing compared to that by tap water bathing, and histopathological findings showed that wound healing was accelerated. In the thermography test, changes in body surface temperature after bathing were investigated in both groups. The heat retention effect was not observed in the tap water bathing group after bathing, whereas it was enhanced in the hot spring bathing group until 30 min after bathing. In conclusion, this study demonstrated that hot spring bathing accelerates wound healing and has a more significant heat retention effect than tap water bathing.

Benefits of Circulating Human Metabolites from Fish Cartilage Hydrolysate on Primary Human Dermal Fibroblasts, an Ex Vivo Clinical Investigation for Skin Health Applications

Due to its significant exposure to stressful environmental factors, the skin undergoes a high remodeling rate over time, which alters not only its appearance but also its functionality. This alteration of the skin, namely photoaging, is characterized by dryness and a loss of elasticity that mainly originates from the dysregulation of dermal fibroblast activities. In order to overcome such tissue outcome, cosmetic products have evolved toward nutricosmetics, thus promoting beauty from within. Among bio-actives of interest, bio-peptides deriving from plant or animal sources may exert various biological activities beyond their nutritional value. However, studies remain mostly descriptive and the mode of action at the cellular level in clinic remains a concern. In a recent clinical trial, it was showed that supplementation with a fish cartilage hydrolysate (FCH) improved signs of chronological and photoaging-induced skin changes in healthy women. Here, using an original ex vivo clinical approach adapted to nutricosmetic purpose, we further demonstrated that this fish cartilage hydrolysate was absorbed and that the circulating metabolites produced in humans following FCH intake stimulate human dermal fibroblast growth, promote specific hyaluronan production, up-regulate elastin synthesis and inhibit MMP-1 and 3 expression along with the enhancement of TGF-β release. Altogether, these data provide clues on the mechanisms likely contributing to the beneficial impact of FCH on human skin functionality by supporting hydration, elasticity and limiting the expression of catabolic factors involved in photoaging onset.

A Collagen Hydrolysate Containing Tripeptides Ameliorates Sarcopenia in Middle-Aged Mice

Collagen peptide (CP) and collagen tripeptide (CTP) are supplementary health foods that exhibit several biological effects. However, the effects of collagen on age-associated sarcopenia and its underlying mechanisms are unclear. C57BL/6J mice (n = 24, 12 months old) were divided into three dietary groups and administered AIN93G (aging control, AC; JA BIO, Suwon, Korea), AIN93G plus 0.2% CP, and AING93G plus 0.2% CTP supplement for 12 weeks. The results indicated that the CP and CTP supplements significantly increased the weight of the quadriceps tibialis anterior and gastrocnemius muscles and reduced body fat. A morphological analysis revealed that the spaces within the muscle cells were tight with attenuated fibrosis following CP and CTP supplementation. Immunohistochemistry was applied and a Western blot analysis was performed to determine the underlying mechanisms. The CTP supplement increased the expression of IGF-1, PI3K/AKT, and mTOR, whereas the CP supplement increased the expression of IGF-1 and AMPK in the gastrocnemius of aging mice. CP and CTP ameliorate age-associated sarcopenia through different mechanisms.

Oral Intake of Chicken Bone Collagen Peptides Anti-Skin Aging in Mice by Regulating Collagen Degradation and Synthesis, Inhibiting Inflammation and Activating Lysosomes

The effect of diet on skin aging has become an interesting research topic. Previous studies have mostly focused on the beneficial effects of collagen peptides derived from marine organisms on the aging skin when administered orally, while the beneficial effects of collagen peptides derived from poultry on aging skin have been rarely reported. In this study, collagen peptides were prepared from chicken bone by enzymatic hydrolysis, and the effect and mechanism of action of orally administered collagen peptides on alleviating skin aging induced by UV combined with D-galactose were investigated. The results showed that the chicken bone collagen had typical characteristics of collagen, and the chicken bone collagen peptides (CPs) were mainly small molecular peptides with a molecular weight of <3000 Da. In vivo experiments showed that CPs had a significant relieving effect on aging skin, indicated by the changes in the compostion and structure of the aging skin, improvement of skin antioxidant level, and inhibition of inflammation; the relieving effect was positively correlated with the dose of CPs. Further investigation showed that CPs first reduce the level of skin oxidation, inhibit the expression of the key transcription factor AP-1 (c-Jun and c-Fos), then activate the TGF-β/Smad signaling pathway to promote collagen synthesis, inhibit the expression of MMP-1/3 to inhibit collagen degradation, and inhibit skin inflammation to alleviate skin aging in mice. Moreover, the skin transcriptome found that lysosomes activated after oral administration of CPs may be an important pathway for CPs in anti-skin aging, and is worthy of further research. These results suggested that CPs might be used as a functional anti-aging nutritional component.

Bamboo Leaf Flavonoids Suppress Oxidative Stress-Induced Senescence of HaCaT Cells and UVB-Induced Photoaging of Mice through p38 MAPK and Autophagy Signaling

With the global escalation of the aging process, the research on aging mechanisms and anti-aging strategies has become a hot spot. As the most external organ of the human body, skin can be used as an ideal organ for the study of endogenous and exogenous aging. Bamboo leaf flavonoids (BLF) possess a variety of biological effects such as antioxidant, anti-bacterial, anti-inflammatory, lipid-lowering, anti-radiation, and anti-aging. However, it is still unclear whether they can delay skin aging. This study aimed to analyze the inhibitory effect of BLF on skin aging and explore their molecular mechanisms. We found that 10–40 μg/mL BLF significantly inhibited the senescence of HaCaT cells induced by AAPH, which might be related to their antioxidant and anti-inflammatory abilities. Further mechanism studies showed that mitogen-activated protein kinase (MAPK), especially the p38 MAPK pathway, was the key to BLF to alleviate the senescence of HaCaT cells. In addition, autophagy was also involved in the anti-senescence effect of BLF. The results were also verified in UVB-induced photoaging mice. Therefore, BLF can be used as a potential therapeutic agent to intervene skin aging in vitro and in vivo.

Exogenous Bioactive Peptides Have a Potential Therapeutic Role in Delaying Aging in Rodent Models

In recent years, some exogenous bioactive peptides have been shown to have promising anti-aging effects. These exogenous peptides may have a mechanism similar to endogenous peptides, and some can even regulate the release of endogenous active peptides and play a synergistic role with endogenous active peptides. Most aging studies use rodents that are easy to maintain in the laboratory and have relatively homogenous genotypes. Moreover, many of the anti-aging studies using bioactive peptides in rodent models only focus on the activity of single endogenous or exogenous active peptides, while the regulatory effects of exogenous active peptides on endogenous active peptides remain largely under-investigated. Furthermore, the anti-aging activity studies only focus on the effects of these bioactive peptides in individual organs or systems. However, the pathological changes of one organ can usually lead to multi-organ complications. Some anti-aging bioactive peptides could be used for rescuing the multi-organ damage associated with aging. In this paper, we review recent reports on the anti-aging effects of bioactive peptides in rodents and summarize the mechanism of action for these peptides, as well as discuss the regulation of exogenous active peptides on endogenous active peptides.

Novel Peptide Motifs Containing Asp-Glu-Gly Target P2Y12 and Thromboxane A2 Receptors to Inhibit Platelet Aggregation and Thrombus Formation

Increasing evidence has shown that collagen peptides have multiple biological activities. Our previous study has separated and identified antiplatelet aggregation peptides Asp-Glu-Gly-Pro (DEGP) from Salmo salar skin. This study is to investigate the cellular target of DEGP on platelets and its underlying mechanism. DEGP inhibited platelet aggregation in a dose-dependent manner induced by 2MeS-ADP and U46619 and significantly attenuated tail thrombosis formation by 30% in mice at the dose of 50 mg/kg body weight. Mechanically, DEGP displayed apparent antagonism effects on TP and P₂Y₁₂ receptors by the drug affinity responsive target stability (DARTS) technique to regulate the phosphorylation of RhoA^S188, PLCβ3^S537, as well as VASP^S157. The molecular docking results revealed a stronger binding energy with the target protein of modified peptides DEGI and DDEGL. Practically, DEGI exhibited the highest inhibition activity against 2MeS-ADP- and U46619-induced platelet aggregation in vitro with IC₅₀ values of 0.88 ± 0.10 and 0.85 ± 0.10 mM, respectively, and comparable antithrombosis activity with aspirin at the dose of 25 mg/kg body weight in vivo. These results indicated the possibility that the peptide motifs containing Asp-Glu-Gly could potentially be developed as a novel therapeutic agent in the prevention and treatment of thrombotic diseases.

Antioxidant defense of fish collagen peptides attenuates oxidative stress in gastric mucosa of experimentally ulcer-induced rats

The aim of the present study was to investigate the ability of fish collagen peptides (FCP) from the skin of great hammerhead shark (Sphyrna mokarran) to avert the occurrence of gastric ulcer in experimental rats. FCP treatment prevented the formation of ulcerative lesions on gastric tissues with 86% of inhibition. The histopathology analysis of gastric tissue revealed that the FCP intake prevented the occurrence of hemorrhage and erosion in gastric tissue with formation of mild edema and necrosis, as well as normalized the pH and volume of gastric juice. It also downregulated the expression of pro-inflammatory marker interferon-ɤ (IFN-ɤ) and upregulated the anti-inflammatory marker interleukin-4 (IL-4) in gastric tissue. FCP is capable to modulate the oxidative stress by enhancing the activity of antioxidant defense enzymes superoxide dismutase (SOD) and catalase and by lowering the levels of membrane lipid peroxidation.

GHRH expression plasmid improves osteoporosis and skin damage in aged mice

The hormone secretion of GHRH-GH-IGF-1 axis in animals was decreased as aging. These hormones play an important role in maintaining bone mass and bone structure, and also affect the normal structure and function of the skin. We used plasmid-based technology to deliver growth hormone releasing hormone (GHRH) to elderly mice. In the current study, 80 and 120 μg/kg pVAX-GHRH plasmid expression plasmid were injected into old mice, the serum GHRH and insulin-like growth factor-1(IGF-1) content were increased within three weeks (P < 0.05). In the groups of 80 and 120 μg/kg plasmid, the content of procollagen type I N-terminal pro-peptide (PINP) in the serum was increased(P < 0.05), and the content of C-terminal telopeptides of type I collagen (CTX-1) in the serum was reduced significantly (P < 0.05). Furthermore, the expression of osteoprotegerin (OPG) and osteocalcin (OCN) in the femur also was increased(P < 0.05). The bone mineral density(BMD)、trabecular bone volume (BV/TV) and trabecular number(Tb.N) of mouse femur were increased significantly (P < 0.05) and trabecular separation(Tb.Sp) was decreased(P < 0.05). There were more trabecular bones in the bone marrow cavity and the trabecular bones are thicker in the groups of 80 and 120 μg/kg plasmid relative to control. The superoxide dismutase (SOD) content in the skin was increased(P < 0.05), and the malondialdehyde (MDA) content was reduced significantly (P < 0.05). Meanwhile, the skin moisture content also increased significantly(P < 0.05). Moreover, the expression of matrix metalloproteinase 3(MMP3) and matrix metalloproteinase 9(MMP9) was decreased in the skin(P < 0.05). The thickness of the dermis and epidermis of the skin had increased significantly(P < 0.05). Skin structure is more dense and complete in the two groups. These results indicate that 80 and 120 μg/kg plasmid-mediated GHRH supplementation can improve osteoporosis and skin aging in aged mice.

Developments for Collagen Hydrolysate in Biological, Biochemical, and Biomedical Domains: A Comprehensive Review

The collagen hydrolysate, a proteinic biopeptide, is used for various key functionalities in humans and animals. Numerous reviews explained either individually or a few of following aspects: types, processes, properties, and applications. In the recent developments, various biological, biochemical, and biomedical functionalities are achieved in five aspects: process, type, species, disease, receptors. The receptors are rarely addressed in the past which are an essential stimulus to activate various biomedical and biological activities in the metabolic system of humans and animals. Furthermore, a systematic segregation of the recent developments regarding the five main aspects is not yet reported. This review presents various biological, biochemical, and biomedical functionalities achieved for each of the beforementioned five aspects using a systematic approach. The review proposes a novel three-level hierarchy that aims to associate a specific functionality to a particular aspect and its subcategory. The hierarchy also highlights various key research novelties in a categorical manner that will contribute to future research.

AP Collagen Peptides Prevent Cortisol-Induced Decrease of Collagen Type I in Human Dermal Fibroblasts

Cortisol is an endogenous glucocorticoid (GC) and primary stress hormone that regulates a wide range of stress responses in humans. The adverse effects of cortisol on the skin have been extensively documented but the underlying mechanism of cortisol-induced signaling is still unclear. In the present study, we investigate the effect of cortisol on collagen type I expression and the effect of AP collagen peptides, collagen tripeptide-rich hydrolysates containing 3% glycine-proline- hydroxyproline (Gly-Pro-Hyp, GPH) from the fish skin, on the cortisol-mediated inhibition of collagen type I and the cortisol-induced signaling that regulates collagen type I production in human dermal fibroblasts (HDFs). We determine that cortisol downregulates the expression of collagen type I. AP collagen peptides or GC receptor (GR) inhibitors recover the cortisol-mediated inhibition of collagen type I and GR activation. AP collagen peptides or GR inhibitors also prevent the cortisol-dependent inhibition of transforming growth factor (TGF)-β signaling. AP collagen peptides or GR inhibitors are effective in the prevention of collagen type I inhibition mediated by cortisol in senescent HDFs and reconstituted human skin models. Taken together, GR signaling might be responsible for the cortisol-mediated inhibition of TGF-β. AP collagen peptides act as GR-mediated signaling blockers, preventing the cortisol-dependent inhibition of collagen type I. Therefore, AP collagen peptides have the potential to improve skin health.

Novel Hyp-Gly-containing antiplatelet peptides from collagen hydrolysate after simulated gastrointestinal digestion and intestinal absorption

Bioactive components causing the antiplatelet activity upon collagen hydrolysate (CH) ingestion have not been clarified yet. This study aimed to identify antiplatelet peptides from CH after simulated gastrointestinal digestion and intestinal absorption. Four antiplatelet peptides containing the Hyp-Gly (OG) sequence including OG, Hyp-Gly-Glu (OGE), Pro-Gly-Glu-Hyp-Gly (PGEOG) and Val-Gly-Pro-Hyp-Gly-Pro-Ala (VGPOGPA) were successfully identified. All four peptides exhibited antiplatelet activity, but OGE and PGEOG exerted stronger activity than OG and VGPOGPA. The IC50 value of OGE and PGEOG was 1.076 mM and 1.167 mM, respectively. These four antiplatelet peptides could survive simulated gastrointestinal digestion and be absorbed intact by Caco-2 cells. Furthermore, plasma stability experiments showed that OG and OGE showed a good stability in human plasma, but PGEOG and VGPOGPA showed a relatively poor stability. In vivo studies indicated that OG and OGE were present in blood after the oral administration of CH. Meanwhile, OGE exerted significant in vivo anti-thrombotic activity after its ingestion. The present study clarifies the antiplatelet components causing the CH activity and highlights the potential application of CH or these four peptides as functional foods to combat thrombosis by inhibiting platelet aggregation.

A novel di-peptide Met-Glu from collagen hydrolysates inhibits platelet aggregation and thrombus formation via regulation of Gq-mediated signaling

Increasing evidence has shown that collagen peptides had various biological activities. In this study, a novel antiplatelet peptide Met-Glu (ME) was separated and identified from silver carp skin by YMC ODS-A C18 separation and ESI-MS/MS analysis. Peptide ME inhibited platelet aggregation and secretion of platelet granules induced by ADP, thrombin and collagen, and significantly attenuated ferric chloride-induced thrombus formation in rats. It did not prolong the bleeding time in mice even at the dose of 300 μmol/kg body weight that showed potent anti-thrombosis effects. Additionally, peptide ME targeted at Gq-protein to downregulate the phosphorylation of PLCβ, an important upstream effector of PI3K/Akt and Erk/MAPK signaling to inhibit intracellular calcium ion mobilization. These results suggest that peptide ME inhibited thrombosis in vivo and inhibited Gq-mediated signaling in platelets, indicating the possibility that ME could potentially be developed as a novel therapeutic agent in the prevention and treatment of thrombotic diseases. PRACTICAL APPLICATIONS: Cardiovascular diseases (CVDs) are the leading cause of mortality and morbidity worldwide. The proximal cause of CVDs is intravascular thrombosis formation, which mostly results from platelet activation, aggregation, and granules secretion. Traditional drugs in the prevention of thrombotic disease, such as aspirin and clopidogrel, are still limited for their side effects, especially bleeding complications. Collagen is a natural source for bioactive peptides and our previous study has shown that collagen peptides could inhibit platelet aggregation in vitro. Understanding the mechanism of collagen peptides on regulation of platelet activation and their in vivo anti-thrombosis activities were important for the development of novel-specific medical food in the prevention of thrombotic diseases.

Cell-Free Fat Extract Increases Dermal Thickness by Enhancing Angiogenesis and Extracellular Matrix Production in Nude Mice

BACKGROUND

Although adipose-derived stem cells (ADSCs) and nanofat exert antiaging effects on skin, they contain cellular components that have certain limitations in clinical practice. Cell-free fat extract (Ceffe) is a fraction purified from nanofat through removal of cellular components and lipid remnants that contains various growth factors.

OBJECTIVES

The purpose of this study was to evaluate the effects of Ceffe on cultured human dermal fibroblasts in vitro and on the dermis of nude mice in vivo.

METHODS

In the in vitro study, human dermal fibroblasts were cultured with Ceffe for 72 hours, followed by flow cytometry measurement of cell proliferation and cell cycle. In the in vivo study, different concentrations of Ceffe were injected into the dorsal skin of nude mice for 4 weeks. The thickness of the dermis; proliferation of cells; density of the capillary; and expressions of type I and III collagen (Col-1 and Col-3), matrix metalloproteinase-1, matrix metalloproteinase-3, tissue inhibitor of metalloproteinase-1, and tissue inhibitor of metalloproteinase-3 were measured through histologic and Western blot analyses.

RESULTS

Ceffe significantly increased cell proliferation in cultured dermal fibroblasts. In the mouse skin, Ceffe significantly increased the thickness of the dermis, number of proliferating cells, density of the capillary, and expressions of Col-1 and Col-3.

CONCLUSIONS

Ceffe increased the dermal thickness of nude mice, possibly by enhancing angiogenesis and extracellular matrix production, and can therefore be used for skin rejuvenation.

Beneficial effects of food supplements based on hydrolyzed collagen for skin care (Review)

Ageing is a complex, multi-step process which involves, among others loss of collagen and elastin. Collagen is found in large amounts in the body, especially in the dermis layer. These fibers provide the skin's normal strength, hydration and mechanical properties. Collagen is largely available, as it can be extracted from many animal sources, it can be easily absorbed upon topical administration, hence it is largely used in the cosmetic and pharmaceutical industry for the treatment of premature aging. Bioactive peptides, such as collagen hydrolyzate, are among the most used ingredients for the development of nutraceuticals - food or food ingredients that have defined physiological effects. Numerous studies have demonstrated that peptides resulted from ingestion of hydrolysate collagen and detected in the blood stream have chemotactic properties for skin fibroblasts, helping the skin restoration process. The purpose of this minireview is to present an update on the use of hydrolyzed collagen for skin care.

Photoprotective Effect of Dietary Galacto-Oligosaccharide (GOS) in Hairless Mice via Regulation of the MAPK Signaling Pathway

This study investigated the suppression of photoaging by galacto-oligosaccharide (GOS) ingestion following exposure to ultraviolet (UV) radiation. To investigate its photoprotective effects, GOS along with collagen tripeptide (CTP) as a positive control was orally administered to hairless mice under UVB exposure for 8 weeks. The water holding capacity, transepidermal water loss (TEWL), and wrinkle parameters were measured. Additionally, quantitative reverse-transcription polymerase chain reaction and Western blotting were used to determine mRNA expression and protein levels, respectively. The GOS or CTP orally-administered group showed a decreased water holding capacity and increased TEWL compared to those of the control group, which was exposed to UVB (CON) only. In addition, the wrinkle area and mean wrinkle length in the GOS and CTP groups significantly decreased. Skin aging-related genes, matrix metalloproteinase, had significantly different expression levels in the CTP and GOS groups. Additionally, the tissue inhibitor of metalloproteinases and collagen type I gene expression in the CTP and GOS groups significantly increased. Oral administration of GOS and CTP significantly lowered the tissue cytokine (interleukin-6 and -12, and tumor necrosis factor-α) levels. There was a significant difference in UVB-induced phosphorylation of JNK, p38, and ERK between the GOS group and the CON group. Our findings indicate that GOS intake can suppress skin damage caused by UV light and has a UV photoprotective effect.

Diet and Skin Aging-From the Perspective of Food Nutrition

We regularly face primary challenges in deciding what to eat to maintain young and healthy skin, defining a healthy diet and the role of diet in aging. The topic that currently attracts maximum attention is ways to maintain healthy skin and delay skin aging. Skin is the primary barrier that protects the body from external aggressions. Skin aging is a complex biological process, categorized as chronological aging and photo-aging, and is affected by internal factors and external factors. With the rapid breakthrough of medicine in prolonging human life and the rapid deterioration of environmental conditions, it has become urgent to find safe and effective methods to treat skin aging. For diet, as the main way for the body to obtain energy and nutrients, people have gradually realized its importance to the skin. Therefore, in this review, we discuss the skin structure, aging manifestations, and possible mechanisms, summarize the research progress, challenges, possible directions of diet management, and effects of foodborne antioxidants on skin aging from the perspective of food and nutrition.

Regulatory Effect of Anwulignan on the Immune Function Through Its Antioxidation and Anti-Apoptosis in D-Galactose-Induced Aging Mice

BACKGROUND

Aging is a spontaneous and inevitable phenomenon of biology, which can lead to the gradual deterioration of tissues and organs. One of the age-related deterioration processes is immunosenescence, which leads to changes in the function of immune systems, including immune cells and associated cytokines. A proper modulation of immune responses can improve the age-related immunosenescence process and then reach healthy aging. Schisandra sphenanthera, a traditional Chinese medicine, has been used as both a medicine and a nutritional supplement for thousands of years. Anwulignan, a monomer compound of Schisandra sphenanthera lignans, has been reported to possess an immunomodulatory effect. Therefore, this study was designed to further explore whether Anwulignan could also modulate the immune functions in aging model mice and the underlying mechanism.

METHODS

D-galactose (D-gal) is often used as an inducer of immunosenescence in animals. In this study, a mice model was created by subcutaneous D-gal (220 mg kg-1) for successive 42 days. Then, the blood and spleen tissue samples were taken for the analysis and observation of cytokine levels, immunoglobulin levels, leukocyte numbers, and the phagocytic activity of macrophages, as well as the histological changes, the proliferation ability of lymphocytes, and the biochemical parameters in the spleen tissue.

RESULTS

Anwulignan significantly increased the serum levels of IL-2, IL-4, IFN-γ, lgG, lgM, and lgA, decreased the content of TNF-α and IL-6 in the aging mice, and increased the blood leukocyte number, the phagocytic activity, the lymphocyte proliferation, and the spleen index in vitro. Anwulignan also significantly increased the activities of SOD and GSH-Px, decreased the contents of MDA and 8-OHdG in the spleen tissue, up-regulated the expressions of Nrf2, HO-1, and Bcl2, down-regulated the expressions of Keap1, Caspase-3, and Bax in the spleen cells, and reduced the apoptosis of spleen lymphocytes.

CONCLUSION

Anwulignan can restore the immune function that is declined in D-gal-induced aging mice partly related to its antioxidant capacity by activating the Nrf2/ARE pathway and downstream enzymes, as well as its anti-apoptotic effect by regulating Caspase-3 and the ratio of Bcl2 to Bax in the spleen.

Protective Effects of Kuding Tea (Ilex kudingcha C. J. Tseng) Polyphenols on UVB-Induced Skin Aging in SKH1 Hairless Mice

In this study, the protective effects of Kuding tea polyphenols (KTPs) on ultraviolet B (UVB)-induced skin injury of SKH1 hairless mice were studied. The ion precipitation method was used for extraction of polyphenols from Kuding tea. High-performance liquid chromatography showed that KTPs contains chlorogenic acid, cryptochlorogenic acid, isochlorogenic acid B, isochlorogenic acid A, and isochlorogenic acid C. SKH1 hairless mice were induced skin aging using 2.0 mW/s intensity of 90 mJ/cm² UV light once a day for seven weeks. The 2.5% and 5% KTPs solution was smeared on 2 cm² of back skin of skin aging mice twice a day. Mouse experiments showed that KTP strongly increased the serum levels of total superoxide dismutase (T-SOD) and catalase (CAT) and reduced those of malondialdehyde, interleukin 6 (IL-6), IL-1β, and tumor necrosis factor alpha (TNF-α) in mice with UVB-induced skin damage. KTP also increased the levels of type 1 collagen (Col I), hydroxyproline, and hyaluronic acid and reduced those of Col III and hydrogen peroxide in the damaged skin tissues of mice. Pathological observations of tissues stained with H & E, Masson’s trichrome, Verhoeff, and toluidine blue showed that KTPs could protect skin cells, collagen, and elastin and decrease the number of mast cells, thus inhibiting skin damage. Quantitative PCR and western blot assays showed that KTP upregulated the mRNA and protein expression of tissue inhibitor of metalloproteinase 1 (TIMP-1), TIMP-2, copper/zinc-SOD, manganese-SOD, CAT, and glutathione peroxidase and downregulated the expression of matrix metalloproteinase 2 (MMP-2) and MMP-9. In addition, the same concentration of KTP had stronger protective effects than vitamin C. The results of this study demonstrate that KTPs have good skin protective effects, as they are able to inhibit UVB-induced skin damage.

Collagen peptides promote photoaging skin cell repair by activating the TGF-β/Smad pathway and depressing collagen degradation

Collagen hydrolysate has been widely used as a nutraceutical agent against skin aging and has gained increasing attention.

Protective Effect of Bovine Elastin Peptides against Photoaging in Mice and Identification of Novel Antiphotoaging Peptides

This study aimed to investigate the protective effects of bovine elastin hydrolysates on UV-induced skin photoaging in mice and to identify the potent antiphotoaging peptides. Results showed that the ingestion of elastin peptides could obviously ameliorate epidermis hyperplasia and fibroblast apoptosis, and increase the content of hydroxyproline and water in photoaging skin in vivo ( p < 0.05). Furthermore, four peptides with elastase inhibitory activity were purified and identified, including GLPY, PY, GLGPGVG, and GPGGVGAL. Interestingly, GLPY and GPGGVGAL exhibited the highest inhibition activity with 58.77% and 42.91% at 10 mΜ, respectively. This might be attributed to the N-terminal Gly, C-terminal Leu, and Pro at the third position of the N-terminus, which showed stronger affinity and interaction with elastase. Moreover, GLPY and GPGGVGAL could also inhibit the apoptosis of fibroblasts effectively at 50 μΜ ( p < 0.01). It suggested that elastin peptides had great potential to prevent and regulate skin photoaging.