Collagen hydrolysate intake improves the loss of epidermal barrier function and skin elasticity induced by UVB irradiation in hairless mice

Effects of Collagen Supplements on Skin Aging: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Collagen supplements are promoted to help aging skin. However, no meta-analysis of randomized controlled trials (RCTs) has examined their effects by funding source and study quality, which may influence outcomes.

METHODS

PubMed, Embase, and Cochrane Library were searched from inception to June 14, 2024.

RESULTS

A total of 23 RCTs with 1474 participants were analyzed. In a meta-analysis of all 23 RCTs, collagen supplements significantly improved skin hydration, elasticity, and wrinkles. However, in the subgroup meta-analysis by funding source, studies not receiving funding from pharmaceutical companies revealed no effect of collagen supplements for improving skin hydration, elasticity, and wrinkles, while those receiving funding from pharmaceutical companies did show significant effects. Similarly, high-quality studies revealed no significant effect in all categories, while low-quality studies revealed a significant improvement in elasticity.

CONCLUSIONS

There is currently no clinical evidence to support the use of collagen supplements to prevent or treat skin aging.

Photoaging protective effect of enzyme extracted pomegranate peel against oxidative damage in UVB-irradiated HaCaT cells

In this study, the ultraviolet B (UVB)-induced skin photoaging inhibitory activity of pomegranate peel extract with increased ellagic acid content through enzymatic hydrolysis was evaluated in HaCaT cells. Among various enzymes, Viscozyme with high tannase and β-glucosidase activities was used, and 1.0 % Viscozyme was added to hydrolyze pomegranate peel for 2 h at 40°C to establish the optimal reaction conditions for high ellagic acid content. Subsequently, when cells were treated with enzyme extracted pomegranate peels (40 μg/mL), the gene expression of matrix metalloproteinases (MMP)-2 and 13, which play key role in skin elasticity and moisture, and the protein expression of MMP13 were downregulated compared to the UVB-control group (UVB-C). In addition, the protein expression levels of tissue inhibitors, metalloproteinase-1 and 2, and collagen type I alpha 1 were upregulated, the gene expression of hyaluronic acid synthase-1, and filaggrin significantly increased, and interleukin-1β increased by photoaging was decreased. Furthermore, compared to the UVB-C, there was a significant increase in the gene expression of superoxide dismutase-1 and glutathione peroxidase, which resulted in a decrease in reactive oxygen species and malondialdehyde levels. These results were confirmed to be due to the inhibition of the mitogen-activated protein kinase pathway and downregulation of the protein expression of phosphorylated extracellular signal-regulated kinase, c-Jun N-terminal kinase, and P38. In conclusion, pomegranate peel, from which ellagic acid was extracted using Viscozyme, showed a reactive oxygen species inhibitory effect in UVB-irradiated HaCaT cells and thus may have a significant potential as a cosmetic ingredient with anti-aging effects.

Uncovering key mechanisms and intervention therapies in aging skin

Advancements in understanding skin aging mechanisms, which encompass both external and internal aging processes, have spurred the development of innovative treatments primarily aimed at improving cosmetic appearance. These findings offer the potential for the development of novel therapeutic strategies aimed at achieving long-term, non-therapy-dependent clinical benefits, including the reversal of aging and the mitigation of associated health conditions. Realizing this goal requires further research to establish the safety and efficacy of targeting aging-related skin changes, such as pigmentation, wrinkling, and collagen loss. Systematic investigation is needed to identify the most effective interventions and determine optimal anti-aging treatment strategies. These reviews highlight the features and possible mechanisms of skin aging, as well as the latest progress and future direction of skin aging research, to provide a theoretical basis for new practical anti-skin aging strategies.

Collagen and Its Derivatives Serving Biomedical Purposes: A Review

Biomaterials have been the subject of extensive research, and their applications in medicine and pharmacy are expanding rapidly. Collagen and its derivatives stand out as valuable biomaterials due to their high biocompatibility, biodegradability, and lack of toxicity and immunogenicity. This review comprehensively examines collagen from various sources, its extraction and processing methods, and its structural and functional properties. Preserving the native state of collagen is crucial for maintaining its beneficial characteristics. The challenges associated with chemically modifying collagen to tailor its properties for specific clinical needs are also addressed. The review discusses various collagen-based biomaterials, including solutions, hydrogels, powders, sponges, scaffolds, and thin films. These materials have broad applications in regenerative medicine, tissue engineering, drug delivery, and wound healing. Additionally, the review highlights current research trends related to collagen and its derivatives. These trends may significantly influence future developments, such as using collagen-based bioinks for 3D bioprinting or exploring new collagen nanoparticle preparation methods and drug delivery systems.

Oral Intake of Linseed Oil Inhibits Skin Barrier Dysfunction in Obese Mice

OBJECTIVE

Obesity is not only a risk factor for lifestyle-related diseases but also causes skin barrier dysfunction, which leads to a reduced quality of life due to dryness, itching, and scratching, and thus requires appropriate treatment. However, there are no studies on this issue. Therefore, this study aimed to examine whether oral intake of linseed oil is effective for skin barrier function in obesity and to confirm how the effect is demonstrated.

METHODS

TSOD mice received either sterile distilled water (Control group) or linseed oil (Omega group), containing a high level of omega-3 fatty acids, including α-linolenic acid, orally for eight weeks. Mice were then irradiated with ultraviolet B (UVB) and three days later, transepidermal water loss (TEWL), which is the primary outcome of skin barrier function, was measured and gross skin appearance was observed. Hematoxylin and eosin (HE) staining and Ki-67 immunostaining were performed on skin samples. mRNA expression levels of the inflammatory markers Tnfα, Cox2, Mcp1, and Hmox1 were measured by real-time reverse transcriptase-polymerase chain reaction (RT-PCR). We also performed fatty acid analysis of skin and erythrocytes by gas chromatography. Statistical analysis was performed using unpaired Student's t-test and Pearson's correlation analysis.

RESULTS

Compared with the Control group, the Omega group exhibited lower TEWL values and little skin erythema. Histological analysis revealed thinner epidermis and fewer Ki-67 positive cells. Additionally, in the Omega group, mRNA levels of four inflammation-related genes were lower, α-linolenic acid levels in both skin and erythrocytes were higher, and a lower n-6/n-3 ratio was observed. And α-linolenic acid levels in the skin were negatively correlated with the expression levels of inflammation-related genes.

CONCLUSION

Oral intake of linseed oil was found to inhibit skin barrier dysfunction in obesity. This effect was mediated by α-linolenic acid, a major component of linseed oil with anti-inflammatory properties, which was taken up by erythrocytes and supplied to the skin. Therefore, oral intake of linseed oil is expected to be a useful therapeutic method for skin barrier dysfunction in obesity.

Preventive and Therapeutic Benefits of Natural Ingredients in Photo-Induced Epidermal Dysfunction

BACKGROUND

The skin, particularly the epidermis, is subjected to various external stresses, including ultraviolet (UV) irradiation. UV irradiation, mainly UVB at wavelength of 280-315 nm, can alter several epidermal functions, including cutaneous inflammation, epidermal hyperproliferation, DNA damage, disruption of epidermal permeability barrier and reduction in stratum corneum hydration levels. Because of the negative impacts of UVB irradiation on epidermal functions, great efforts have been made to develop regimens for the protection of alterations in epidermal function induced by UV irradiation.

SUMMARY

While sunscreen can provide physical barrier to UV light, some natural ingredients can also effectively protect the skin from UVB irradiation-induced damages. Studies have demonstrated that either topical or oral administrations of some natural ingredients attenuate UVB irradiation-induced alterations in the epidermal function. The underlying mechanisms by which natural ingredients improve epidermal functions are attributable to antioxidation, stimulation of keratinocyte differentiation, increases in the content of epidermal natural moisturizers and inhibition of inflammation.

KEY MESSAGE

Some natural ingredients exhibit protective and therapeutical benefits in photo-induced epidermal dysfunctions via divergent mechanisms.

Use of Collagen in Cosmetic Products

Collagen (CLG) belongs to the family of fibrillar proteins and is composed of left-handed α polypeptide chains, which, twisting around themselves and their axis, form a right-handed superhelix. In the chemical structure, it contains mainly proline, hydroxyproline, glycine, and hydroxylysine. It occurs naturally in the dermis in the form of fibers that provide the skin with proper density and elasticity. The review aimed to present the types of collagen protein, factors affecting its structure and its unusual role in the functioning of the human body. Also, an overview of cosmetic products containing collagen or its derivatives, the characteristics of the formulas of these products, and the effects of their use were presented. Throughout the market, there are many cosmetic and cosmeceutical products containing CLG. They are in the form of fillers administered as injections, belonging to the group of the oldest tissue fillers; products administered orally and for topical use, such as creams, gels, serums, or cosmetic masks. Analyzed studies have shown that the use of products with collagen or its peptides improves the general condition of the skin and delays the aging process by reducing the depth of wrinkles, improving hydration (in the case of oral preparations), reducing transepithelial water loss (TEWL), as well as improving skin density and elasticity. In addition, oral application of bioactive CLG peptides has shown a positive effect on the nails, reducing the frequency of their breakage.

Low-molecular-weight collagen peptides supplement promotes a healthy skin: A randomized, double-blinded, placebo-controlled study

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.

Application of Molecular Dynamics Simulations to Determine Interactions between Canary Seed (Phalaris canariensis L.) Bioactive Peptides and Skin-Aging Enzymes

Food bioactive peptides are well recognized for their health benefits such as antimicrobial, antioxidant, and antihypertensive benefits, among others. Their drug-like behavior has led to their potential use in targeting skin-related aging factors like the inhibition of enzymes related with the skin-aging process. In this study, canary seed peptides (CSP) after simulated gastrointestinal digestion (<3 kDa) were fractioned by RP-HPLC and their enzyme-inhibition activity towards elastase and tyrosinase was evaluated in vitro. CSP inhibited elastase (IC50 = 6.2 mg/mL) and tyrosinase (IC50 = 6.1 mg/mL), while the hydrophobic fraction-VI (0.2 mg/mL) showed the highest inhibition towards elastase (93%) and tyrosinase (67%). The peptide fraction with the highest inhibition was further characterized by a multilevel in silico workflow, including physicochemical descriptor calculations, antioxidant activity predictions, and molecular dynamics-ensemble docking towards elastase and tyrosinase. To gain insights into the skin permeation process during molecular dynamics simulations, based on their docking scores, five peptides (GGWH, VPPH, EGLEPNHRVE, FLPH, and RPVNKYTPPQ) were identified to have favorable intermolecular interactions, such as hydrogen bonding of polar residues (W, H, and K) to lipid polar groups and 2-3 Å van der Waals close contact of hydrophobic aliphatic residues (P, V, and L). These interactions can play a critical role for the passive insertion of peptides into stratum corneum model skin-membranes, suggesting a promising application of CSP for skin-aging treatments.

Tolerability and efficacy assessment of an oral collagen supplement for the improvement of biophysical and ultrasonographic parameters of skin in middle eastern consumers

BACKGROUND

Topical skin care products often do not reach the deeper layers of the skin, and oral hydrolyzed collagen is one of the newest and most popular systemic supplementations for skin rejuvenation. However, there are limited information in case of Middle Eastern consumers OBJECTIVE: The purpose of this study was to evaluate the tolerability and efficacy of an oral collagen supplement for improvement of skin elasticity, hydration, and roughness in Middle Eastern consumers.

METHODS AND MATERIALS

It was a 12-week, before-after clinical study, conducted on 20 participants (18 women and 2 men) aged 44.15 ± 5.36 years with skin type III-IV. Skin elasticity parameters (R0, R2, R5, and R7), skin hydration and friction, as well as the thickness and echo density of the dermis, were measured after six and 12 weeks daily intake of the study product, as well as 4 weeks after stopping its use (week 16). Participants' satisfaction was assessed on the basis of their answers to the standard questionnaire, and tolerability of the product was assessed by monitoring the adverse effects.

RESULTS

A significant improvement was detected in R2, R5, and skin friction at week 12 (p-values 0.041, 0.012 and <0.01, respectively). At week 16, the values remained at an increased level, which indicates the persistence of the results. The increase of dermis density in week 16 was also significant (p-value = 0.03). Moderate overall satisfaction was reported with the treatment, and a few gastrointestinal complications were reported.

CONCLUSION

The study demonstrated that oral collagen peptides could significantly improve the skin elasticity, roughness, and dermis echo density, and they also proved to be safe and well-tolerated.

Collagen supplementation in skin and orthopedic diseases: A review of the literature

Collagen is one of the main components of the extracellular matrix of the dermis and articular cartilage and influences the body's mechanical, organizational, and tissue formation properties. Produced from food industry by-products, it is considered a nutraceutical product widely used as an ingredient or supplement in food, pharmaceutical, and cosmetic industries. This study aimed to conduct a literature review on the scientific evidence regarding the beneficial effects of collagen consumption in the treatment of skin and orthopedic diseases. Literature data have shown that hydrolyzed collagen supplementation promotes skin changes, such as decreased wrinkle formation; increased skin elasticity; increased hydration; increased collagen content, density, and synthesis, which are factors closely associated with aging-related skin damage. Regarding orthopedic changes, collagen supplementation increases bone strength, density, and mass; improves joint stiffness/mobility, and functionality; and reduces pain. These aspects are associated with bone loss due to aging and damage caused by strenuous physical activity. Thus, this review addresses the economic and health potential of this source of amino acids and bioactive peptides extracted from food industry by-products.

Protective Effect of Bifidobacterium animalis subs. lactis MG741 as Probiotics against UVB-Exposed Fibroblasts and Hairless Mice

Skin photoaging, which causes wrinkles, increased epidermal thickness, and rough skin texture, is induced by ultraviolet B (UVB) exposure. These symptoms by skin photoaging have been reported to be involved in the reduction of collagen by the expression of matrix metalloproteinases (MMPs) and activator protein-1 (AP-1). This study investigated the protective effects of Bifidobacterium animalis subsp. lactis MG741 (Bi. lactis MG741) in Hs-68 fibroblasts and hairless mice (HR-1) following UVB exposure. We demonstrated that the Bi. lactis MG741 reduces wrinkles and skin thickness by downregulating MMP-1 and MMP-3, phosphorylation of extracellular signal-regulated kinase (ERK), and c-FOS in fibroblasts and HR-1. Additionally, in UVB-irradiated dorsal skin of HR-1, Bi. lactis MG741 inhibits the expression of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), an inflammation-related factor. Thus, Bi. lactis MG741 has the potential to prevent wrinkles and skin inflammation by modulating skin photoaging markers.

Potential Cosmetic Active Ingredients Derived from Marine By-Products

The market demand for marine-based cosmetics has shown a tremendous growth rate in the last decade. Marine resources represent a promising source of novel bioactive compounds for new cosmetic ingredient development. However, concern about sustainability also becomes an issue that should be considered in developing cosmetic ingredients. The fisheries industry (e.g., fishing, farming, and processing) generates large amounts of leftovers containing valuable substances, which are potent sources of cosmeceutical ingredients. Several bioactive substances could be extracted from the marine by-product that can be utilized as a potent ingredient to develop cosmetics products. Those bioactive substances (e.g., collagen from fish waste and chitin from crustacean waste) could be utilized as anti-photoaging, anti-wrinkle, skin barrier, and hair care products. From this perspective, this review aims to approach the potential active ingredients derived from marine by-products for cosmetics and discuss the possible activity of those active ingredients in promoting human beauty. In addition, this review also covers the prospect and challenge of using marine by-products toward the emerging concept of sustainable blue cosmetics.

Nutricosmetics: A new frontier in bioactive peptides' research toward skin aging

Food derived bioactive peptides are small protein fragments (2-20 amino acids long) that can exhibit health benefits, beyond basic nutrition. For example, food bioactive peptides can act as physiological modulators with hormone or drug-like activities including anti-inflammatory, antimicrobial, antioxidant, and the ability to inhibit enzymes related to chronic disease metabolism. Recently, bioactive peptides have been studied for their potential role as nutricosmetics. For example, bioactive peptides can impart skin-aging protection toward extrinsic (i.e., environmental and sun UV-ray damage) and intrinsic (i.e., natural cell or chronological aging) factors. Specifically, bioactive peptides have demonstrated antioxidant and antimicrobial activates toward reactive oxygen species (ROS) and pathogenic bacteria associated with skin diseases, respectively. The anti-inflammatory properties of bioactive peptides using in vivo models has also been reported, where peptides have shown to decreased the expression of IL-6, TNF-α, IL-1β, interferon-γ (INF-γ), and interleukin-17 (IL-17) in mice models. This chapter will discuss the main factors that trigger skin-aging processes, as well as provide examples of in vitro, in vivo, and in silico applications of bioactive peptides in relation to nutricosmetic applications.

Effect of a Topical Collagen Tripeptide on Antiaging and Inhibition of Glycation of the Skin: A Pilot Study

The glycation process has been recognized as one of the critical parameters that accelerate signs of skin aging, especially in skin exposed to environment factors, such as ultraviolet radiation. Although previous studies showed the anti-inflammatory and antiaging properties of the hydrolyzed collagen tripeptide (CTP), its exact mechanism is not fully understood. Therefore, in this study, we sought to investigate the effect of a topical CTP on facial skin. Our group designed a 4 week prospective, single-arm study of 22 Asian women who applied topical CTP. We observed significant improvements in skin wrinkles, elasticity, and density with a reduction in skin accumulation of advanced glycated end products (AGEs) at week 4 without any adverse effects. The in vitro study revealed a preventive effect of the topical CTP on the accumulation of AGEs, denatured collagen production, and reactive oxygen species in dermal fibroblasts. Moreover, treatment with the CTP decreased induction of matrix metalloproteinases while increasing the collagen 1 level. These results suggest that the application of a topical CTP might improve clinical aging phenotypes via the inhibition of glycation and oxidative stress, leading to a delay in cellular aging.

GT Collagen Improves Skin Moisturization in UVB-Irradiated HaCaT Cells and SKH-I Hairless Mice

We investigated the effects of GT collagen (Geltech low-molecular-weight fish collagen, FC) on skin moisturization in ultraviolet B (UVB)-irradiated HaCaT cells and SKH-I hairless mice. In vitro, we measured the expression of mRNA genes and proteins related to the skin moisturizing mechanism, hyaluronic acid concentrations, and sphingomyelin concentrations. As a result, FC increased the expression of LCB1, DEGS1, elastin, UGTrel7, and GlcNAc mRNA in UVB-irradiated HaCaT cells. Also, hyaluronic acid level, sphingomyelin level, and protein expressions of hyaluronan synthase (HAS)2 and CerS4 were increased compared to those in the UVB-irradiated control group. In vivo, we measured skin hydration through the expression of mRNA genes and proteins related to the skin moisturizing mechanism and found that the protein expression of HAS2 and CerS4 was increased in the groups taking FC. Moreover, FC intake increased the expression of LCB1, DEGS1, fibrilin-1, UGTrel8, and GlcNAc mRNA in UVB-irradiated SKH-I hairless mice. These results suggest that FC can be utilized to develop products aimed at improving skin moisturization.

Proteoglycan Combined with Hyaluronic Acid and Hydrolyzed Collagen Restores the Skin Barrier in Mild Atopic Dermatitis and Dry, Eczema-Prone Skin: A Pilot Study

Dry and eczema-prone skin conditions such as atopic dermatitis and xerotic eczema primarily indicate an impaired skin barrier function, which leads to chronic pruritus. Here, we investigated the effects of a novel emollient containing H.ECM^TM liposome, which contains a soluble proteoglycan in combination with hydrolyzed collagen and hyaluronic acid. A prospective, single-arm study was conducted on 25 participants with mild atopic dermatitis or dry skin to assess the hydration and anti-inflammatory effect of the novel emollient applied daily over four weeks. All efficacy parameters, including itching severity, transepidermal water loss, and skin hydration, improved significantly after four weeks. The in vitro and ex vivo studies confirmed the restoration of the skin’s barrier function. The study revealed the clinical and laboratory efficacy of H.ECM^TM liposome in reducing itching and improving the skin’s barrier integrity. Thus, the use of H.ECM^TM liposome can be considered a therapeutic option for dry and eczema-prone skin.

Dietary Collagen Hydrolysates Ameliorate Furrowed and Parched Skin Caused by Photoaging in Hairless Mice

Collagen hydrolysates have been suggested as a favorable antiaging modality in skin photoaged by persistent exposure to ultraviolet radiation (UV). The current study evaluated the beneficial effect of collagen hydrolysates (fsCH) extracted from Pangasius hypophthalmus fish skin on wrinkle formation and moisture preservation in dorsal skin of hairless mice challenged with UV-B. Inter-comparative experiments were conducted for anti-photoaging among fsCH, retinoic acid (RA), N-acetyl-D-glucosamine (NAG), and glycine-proline-hydroxyproline (GPH). Treating human HaCaT keratinocytes with 100−200 μg/mL fsCH reciprocally ameliorated the expression of aquaporin 3 (AQP3) and CD44 deranged by UV-B. The UV-B-induced deep furrows and skin thickening were improved in parched dorsal skin of mice supplemented with 206–412 mg/kg fsCH as well as RA and GPH. The UV-B irradiation enhanced collagen fiber loss in the dorsal dermis, which was attenuated by fsCH through enhancing procollagen conversion to collagen. The matrix metalloproteinase expression by UV-B in dorsal skin was diminished by fsCH, similar to RA and GPH, via blockade of collagen degradation. Supplementing fsCH to UV-B-irradiated mice decreased transepidermal water loss in dorsal skin with reduced AQP3 level and restored keratinocyte expression of filaggrin. The expression of hyaluronic acid synthase 2 and hyaluronidase 1 by UV-B was remarkably ameliorated with increased production of hyaluronic acid by treating fsCH to photoaged mice. Taken together, fsCH attenuated photoaging typical of deep wrinkles, epidermal thickening, and skin water loss, like NAG, RA, or GPH, through inhibiting collagen destruction and epidermal barrier impairment.

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.

Long-term intake of ginger protease-degraded collagen hydrolysate reduces blood lipid levels and adipocyte size in mice

Collagen hydrolysate has various beneficial effects, such as bone strengthening, joint/skin protection and lipid metabolism regulation. In this study, the anti-obesity activity of ginger protease-degraded collagen hydrolysate (GDCH) was evaluated in BALB/c mice fed diets containing 14% casein (control group) or 10% casein +4% GDCH (GDCH group) for 10 weeks. In the GDCH group, triglyceride (TG) and cholesterol (CHO) levels in blood and adipocyte size in white adipose tissue were significantly decreased compared with those of the control group. Further, gene expression related to fatty acid synthesis, such as acetyl-CoA carboxylase, fatty acid synthase and stearoyl-CoA desaturase, was decreased in the liver and white adipose tissue of GDCH-fed mice. On the other hand, single oral administration of GDCH did not result in decrease in blood TG and CHO compared with vehicle and casein in ICR mice pre-administered soybean oil. These results suggest that the GDCH-induced decreases in tissue and blood lipids occur through long-term alterations in lipid metabolism, not transient inhibition of lipid absorption. The lipid-lowering effects exhibited by partial substitution of casein with GDCH imply the possibility that daily supplementation of GDCH contributes to prevention/attenuation of obesity and hyperlipidemia.

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Long-term feeding of ginger-protease degraded collagen hydrolysate (GDCH) in mice.

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Blood triglycerides and cholesterol were decreased by GDCH intake.

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Adipocyte size of white adipose tissue was reduced by GDCH intake.

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Fatty acid synthesis genes were down-regulated by GDCH intake.

The beneficial role of functional food components in mitigating ultraviolet-induced skin damage

Excessive exposure to ultraviolet (UV) radiation can chemically alter biological molecules and is one of the major environmental health risks with potential to damage the structure and function of the skin. Numerous dietary supplements are known to optimize the skin's defenses against radiation exposure. Several studies in which the beneficial roles of functional food components, that can protect against UV-induced skin damage, have been demonstrated. Supplemental dietary sphingomyelin maintains covalently bound ω-hydroxy ceramides to avert skin barrier defects after UVB irradiation. The oral administration of collagen hydrolysates has been shown to limit decreases in skin elasticity via increases in the dermal hyaluronic acid content. Milk fermented with lactic acid bacteria has been shown to augment DNA repair mechanisms and improve skin immunity in the aftermath of UVB damage. Furthermore, long-term ingestion of fermented milk containing lactic acid bacteria, collagen hydrolysates and sphingomyelin increases the minimal erythema dose (MED) in human subjects with moderate sunburn or redness and tanned skin after exposure to UV solar radiation. Thus, products containing these functional food components are one means by which the adverse effects of UV radiation on the skin can be mitigated.

Transdermal permeation effect of collagen hydrolysates of deer sinew on mouse skin, ex vitro, and antioxidant activity, increased type I collagen secretion of percutaneous proteins in NIH/3T3 cells

BACKGROUND

The collagen hydrolysates as a cosmetic material have already been wide application. At present, few studies concern with transdermal behavior of collagen hydrolysates in vitro.

OBJECTIVE

Deer sinew contains rich collagen with a content of 82.12%. Thus, this article mainly studies the transdermal effect of collagen hydrolysates of deer sinew (DSCH) on mouse skin, ex vitro, and to explore skincare protection of percutaneous proteins.

METHODS

Collagen hydrolysates of deer sinew were extracted by 0.2% HCl and a two-step enzymatic method of pepsin-trypsin. The content of 17 amino acids of DSCH was detected by precolumn derivatization RP-HPLC. Using Franz diffusion cell systems studied the transdermal effect of DSCH and then examined the percutaneous rate and molecular weight distribution of percutaneous proteins (PP). Further, we studied the bioactivity of PP in vitro, such as the total antioxidant capacity and collagen secretion in NIH/3T3 cells.

RESULTS

About 8.0% DSCH could penetrate skin of mouse, the molecular weight of PP mainly distributed in 5 ~ 13 kDa, accounted for 91.55%. Compared with the antioxidant activity of DSCH, PP had obvious antioxidant activity of scavenging radical cation. Meanwhile, PP promoted cell proliferation and collagen I secretion in fibroblast cells; however, level of type III collagen has no change.

CONCLUSION

Collagen hydrolysates of deer sinew may be used as cosmetic material to protect the skin from oxidative stress, to prevent premature skin aging.

Potential role of natural bioactive peptides for development of cosmeceutical skin products

In recent years, consumers' demand for cosmeceutical products with protective and therapeutic functions derived from natural sources have caused this industry to search for alternative active ingredients. Bioactive peptides have a wide spectrum of bioactivities, which make them ideal candidates for development of these cosmeceutical products. In vitro studies have demonstrated that bioactive peptides (obtained as extracts, hydrolysates, and/or individual peptides) exhibit biological properties including antioxidant, antimicrobial, and anti-inflammatory activities, in addition to their properties of inhibiting aging-related enzymes such as elastase, collagenase, tyrosinase and hyaluronidase. Some studies report multifunctional bioactive peptides that can simultaneously affect, beneficially, multiple physiological pathways in the skin. Moreover, in vivo studies have revealed that topical application or consumption of bioactive peptides possess remarkable skin protection. These properties suggest that bioactive peptides may contribute in the improvement of skin health by providing specific physiological functions, even though the mechanisms underlying the protective effect have not been completely elucidated. This review provides an overview of in vitro, in silico and in vivo properties of bioactive peptides with potential use as functional ingredients in the cosmeceutical field. It also describes the possible mechanisms involved as well as opportunities and challenges associated with their application.

Nutricosmetics: A brief overview

The nutricosmetics are products and ingredients that act as nutritional supplements to care skin, nails, and hair natural beauty. They work from the inside to promote beauty from within. Nutricosmetic is the latest trend in the beauty industry. This tendency rapidly gained many followers because it fits with the modern culture: Today, consumers are very careful with the food that they introduce into their body, and there is also an increasing demand for natural products able to enhance one's health and beauty without side effects and significant traction before use. However, many nutricosmetic products are considered effective due to the historical use and word of mouth. Comprehensive analysis of the global nutricosmetics market is conducted considering form, end-user applications, and some product components such as collagen, peptides, proteins, vitamins, carotenes, minerals, and omega-3 fatty acid are reported. Plant extract ingredients used in nutricosmetic are also described.

Anti-Photoaging Effects of Four Insect Extracts by Downregulating Matrix Metalloproteinase Expression via Mitogen-Activated Protein Kinase-Dependent Signaling

Insects are some of the most diverse organisms on the planet, and have potential value as food or medicine. Here, we investigated the photoprotective properties of insect extracts using hairless mice. The alleviating wrinkle formation effects of insect extracts were evaluated by histological skin analysis to determine epidermal thickness and identify collagen fiber damage. Moreover, we investigated the ability of the insect extracts to alleviate UVB-induced changes to matrix metalloproteinases (MMPs), oxidative damage, the mitogen-activated protein kinases (MAPKs) signaling pathway, and the expression of pro-inflammatory cytokines. Insect extracts reduced UVB-induced skin winkles, epidermal thickening, and collagen breakdown, and alleviated the epidermal barrier dysfunction induced by UVB, including the increased loss of transepidermal water. Moreover, the expression of skin hydration-related markers such as hyaluronic acid, transforming growth factor-beta (TGF-β), and procollagen was upregulated in the group treated with insect extracts compared to the vehicle-treated group after ultraviolet B (UVB) exposure. UVB irradiation also upregulated the expression of MMPs, the phosphorylation of MAPKs, and pro-inflammatory cytokines, which were all attenuated by the oral administration of insect extracts. These results indicate the photoaging protection effect of insect extracts and the underlying mechanism, demonstrating the potential for clinical development.

Changes in composition and content of food-derived peptide in human blood after daily ingestion of collagen hydrolysate for 4 weeks

BACKGROUND

Daily ingestion of collagen hydrolysate for a long period improves skin and joint conditions. It has been speculated that the beneficial effects are exerted by food-derived hydroxyproline (Hyp) peptides, which are detected in human blood after single ingestions. In the present study, to investigate the effect of long-term ingestion of collagen hydrolysate on Hyp peptides profile in blood, the concentrations of Hyp-peptides in human blood before and after daily ingestion for a long period were examined.

RESULTS

Hyp-peptides increased to a maximum level at 1 h after ingestion and reverted to their initial levels within 24 h during experimental period. Pro-Gly and Hyp-peptides such as Pro-Hyp-Gly, Pro-Hyp, Ile-Hyp, Leu-Hyp, Hyp-Gly, Glu-Hyp and Ala-Hyp were identified in the blood after ingestion of collagen hydrolysate at 4.5 g day^-1 for 4 weeks. For the whole period, Pro-Hyp was the leading compound. The compositional rate of Hyp-Gly showed a tendency to increase, while that of Pro-Hyp tended to decrease after daily ingestion.

CONCLUSION

The present results indicate that daily ingestion of collagen hydrolysate for a long period can change compositional rate of Hyp peptides in human blood. This fact suggests that long-term ingestion of collagen hydrolysate might change exo- or endo-type protease activity in the digestive tract, which may consequently promote beneficial effects. © 2017 Society of Chemical Industry.

The anti-photoaging effect of antioxidant collagen peptides from silver carp (Hypophthalmichthys molitrix) skin is preferable to tea polyphenols and casein peptides

Applying antioxidants to attenuate skin photoaging has received great attention. In this study, antioxidant collagen peptides (ACPs) with different activities were prepared using different proteases, called high (HCP), medium (MCP) and low antioxidant collagen peptides (LCP). The effects of ACPs, tea polyphenols (TP) and casein peptides (CP) on the photoaged skin of mice were evaluated and compared. Ingestion of ACPs significantly alleviated UV-induced abnormal alterations of skin components and antioxidative indicators in both serum and skin (p < 0.05). In addition, HCP had the best effect on protecting skin from photoaging among the three collagen peptides, with no significant differences between MCP and LCP (p > 0.05). TP and CP, with higher antioxidant activity in vitro, only significantly increased hydroxyproline content (only in the TP group) and CAT activity and decreased protein carbonyl content at week 2, showing a much weaker effect than that of the ACP groups. The histological analysis result further demonstrates that ACPs exerted a stronger beneficial effect on normalizing skin structure and collagen arrangement than TP and CP. Accordingly, ACPs have potential for nutraceuticals as anti-skin-photoaging ingredients.

The effect of collagen hydrolysates from silver carp (Hypophthalmichthys molitrix) skin on UV-induced photoaging in mice: molecular weight affects skin repair

The use of collagen hydrolysates (CHs) as a nutraceutical agent in skin aging has gained increasing attention. Here, the effects of various doses and molecular weights of CH from silver carp skin on photoaging in mice were investigated. The ingestion of CH at 50, 100 and 200 mg per kg body weight led to a dose-dependent increase in the hydroxyproline, hyaluronic acid and moisture contents of the skin, but it had no significant effect on the mice body weight, or on the spleen or thymus index. Furthermore, ingesting CH with lower (LMCH, 200-1000 Da, 65%) and higher molecular weight (HMCH, >1000 Da, 72%) significantly increased the skin components and improved the antioxidative enzyme activities in both serum and skin (p < 0.05); LMCH performed better than HMCH. By contrast, gelatin (>120 kDa) ingestion did not bring a significant change compared to model mice. These results indicated that LMCH exerted a stronger beneficial effect on the skin than did either HMCH and gelatin, which supported the feasibility of using LMCH as a dietary supplement from silver carp skin to combat photoaging.

Oral Ingestion of Collagen Hydrolysate Leads to the Transportation of Highly Concentrated Gly-Pro-Hyp and Its Hydrolyzed Form of Pro-Hyp into the Bloodstream and Skin

Collagen hydrolysate is a well-known dietary supplement for the treatment of skin aging; however, its mode of action remains unknown. Previous studies have shown that the oral ingestion of collagen hydrolysate leads to elevated levels of collagen-derived peptides in the blood, but whether these peptides reach the skin remains unclear. Here, we analyzed the plasma concentration of collagen-derived peptides after ingestion of high tripeptide containing collagen hydrolysate in humans. We identified 17 types of collagen-derived peptides transiently, with a particular enrichment in Gly-Pro-Hyp. This was also observed using an in vivo mouse model in the plasma and skin, albeit with a higher enrichment of Pro-Hyp in the skin. Interestingly, this Pro-Hyp enrichment in the skin was derived from Gly-Pro-Hyp hydrolysis, as the administration of pure Gly-Pro-Hyp peptide led to similar results. Therefore, we propose that functional peptides can be transferred to the skin by dietary supplements of collagen.

The efficacy study of the combination of tripeptide-10-citrulline and acetyl hexapeptide-3. A prospective, randomized controlled study

BACKGROUND

Bioactive peptides have beneficial effects on the skin.

OBJECTIVE

We investigated to evaluate the effect of acetyl hexapeptide-3 and tripeptide-10 citrulline and the possible synergism between these two peptides.

METHODS

Twenty-four healthy volunteers were randomized to receive combination of acetyl hexapeptide-3 with tripeptide-10 citrulline (Group G1), tripeptide-10 citrulline (Group, G2), acetyl hexapeptide-3 (Group G3), or neither peptide (Group G4) for 60 days. Skin properties evaluated included skin microtopography, parameters cR2 and cR3, and transepidermal water loss (TEWL) using a skin visioscan and a tewameter, respectively.

RESULTS

After 20 days, the measurements between G1 and G2 groups (cR2 P=.045, cR3 P=.044), G2 and G3 groups (cR2 P=.017, cR3 P=.017), G3 and G4 groups (CR2 P=.022), and G2 and G4 groups (cR3 P=.028) from baseline were significant. After 60 days, measurements between groups G1 and G3 (cR2 P=.016, cR3 P=.025), groups G2 and G3 (cR2 P=.044, cR3= P=.044), and groups G1 and G4 (cR2 P=.025) were significant. After 20 days, changes in TEWL between groups G1 and G3 (P=.03), groups G2 and G3 (P=.045), and groups G3 and G4 (P=.025) were significant. After 40 days, changes between groups G2 and G3 (P=.028) and groups G3 and G4 (P=.01) from baseline were significant.

CONCLUSION

Our results confirm the antiwrinkle activity of acetyl hexapeptide-3. A significant decrease in TEWL with acetyl hexapeptide-3 treatment is observed. We provided clinical evidence for the antiwrinkle efficacy of tripeptide-10 citrulline and possibly TEWL. The underlying mechanism by which these two peptides can act synergistically was not clear in this study.

Exopolysaccharides Isolated from Milk Fermented with Lactic Acid Bacteria Prevent Ultraviolet-Induced Skin Damage in Hairless Mice

Background: We studied the mechanism by which fermented milk ameliorates UV-B-induced skin damage and determined the active components in milk fermented with lactic acid bacteria by evaluating erythema formation, dryness, epidermal proliferation, DNA damage and cytokine mRNA levels in hairless mice exposed to acute UV-B irradiation. Methods: Nine week-old hairless mice were given fermented milk (1.3 g/kg BW/day) or exopolysaccharide (EPS) concentrate (70 mg/kg BW/day) orally for ten days. Seven days after fermented milk or EPS administration began, the dorsal skin of the mice was exposed to a single dose of UV-B (20 mJ/cm²). Results: Ingestion of either fermented milk or EPS significantly attenuated UV-B-induced erythema formation, dryness and epidermal proliferation in mouse skin. Both fermented milk and EPS were associated with a significant decrease in cyclobutane pyrimidine dimers and upregulated mRNA levels of xeroderma pigmentosum complementation group A (XPA), which is involved in DNA repair. Furthermore, administration of either fermented milk or EPS significantly suppressed increases in the ratio of interleukin (IL)-10/IL-12a and IL-10/interferon-gamma mRNA levels. Conclusion: Together, these results indicate that EPS isolated from milk fermented with lactic acid bacteria enhanced DNA repair mechanisms and modulated skin immunity to protect skin against UV damage.

Optimization of dose of collagen hydrolysate to prevent UVB-irradiated skin damage

Collagen hydrolysate (CH) was orally administered to UVB-irradiated hairless mice at doses of 20, 200-2000 mg/kg BW/day. The low dose of CH increased the skin hydration and reduced the transepidermal water loss on damaged skin. These results suggested the optimal dose of collagen to improve the UV-damaged skin condition.

The effect of oral collagen peptide supplementation on skin moisture and the dermal collagen network: evidence from an ex vivo model and randomized, placebo-controlled clinical trials

BACKGROUND

Skin dryness and an accelerated fragmentation of the collagen network in the dermis are hallmarks of skin aging. Nutrition is a key factor influencing skin health and consequently its appearance. A wide range of dietary supplements is offered to improve skin health. Collagen peptides are used as a bioactive ingredient in nutricosmetic products and have been shown in preclinical studies to improve skin barrier function, to induce the synthesis of collagen and hyaluronic acid, and to promote fibroblast growth and migration. Our aim was to investigate the effect of oral supplementation with specific collagen peptides on skin hydration and the dermal collagen network in a clinical setting.

METHODS

Two placebo-controlled clinical trials were run to assess the effect of a daily oral supplementation with collagen peptides on skin hydration by corneometry, on collagen density by high-resolution ultrasound and on collagen fragmentation by reflectance confocal microscopy. Human skin explants were used to study extracellular matrix components in the presence of collagen peptides ex vivo.

RESULTS

Oral collagen peptide supplementation significantly increased skin hydration after 8 weeks of intake. The collagen density in the dermis significantly increased and the fragmentation of the dermal collagen network significantly decreased already after 4 weeks of supplementation. Both effects persisted after 12 weeks. Ex vivo experiments demonstrated that collagen peptides induce collagen as well as glycosaminoglycan production, offering a mechanistic explanation for the observed clinical effects.

CONCLUSION

The oral supplementation with collagen peptides is efficacious to improve hallmarks of skin aging.

Dietary Milk Sphingomyelin Prevents Disruption of Skin Barrier Function in Hairless Mice after UV-B Irradiation

Exposure to ultraviolet-B (UV-B) irradiation causes skin barrier defects. Based on earlier findings that milk phospholipids containing high amounts of sphingomyelin (SM) improved the water content of the stratum corneum (SC) in normal mice, here we investigated the effects of dietary milk SM on skin barrier defects induced by a single dose of UV-B irradiation in hairless mice. Nine week old hairless mice were orally administrated SM (146 mg/kg BW/day) for a total of ten days. After seven days of SM administration, the dorsal skin was exposed to a single dose of UV-B (20 mJ/cm²). Administration of SM significantly suppressed an increase in transepidermal water loss and a decrease in SC water content induced by UV-B irradiation. SM supplementation significantly maintained covalently-bound ω-hydroxy ceramide levels and down-regulated mRNA levels of acute inflammation-associated genes, including thymic stromal lymphopoietin, interleukin-1 beta, and interleukin-6. Furthermore, significantly higher levels of loricrin and transglutaminase-3 mRNA were observed in the SM group. Our study shows for the first time that dietary SM modulates epidermal structures, and can help prevent disruption of skin barrier function after UV-B irradiation.

Effect of orally administered collagen hydrolysate on gene expression profiles in mouse skin: a DNA microarray analysis

Dietary collagen hydrolysate has been hypothesized to improve skin barrier function. To investigate the effect of long-term collagen hydrolysate administration on the skin, we evaluated stratum corneum water content and skin elasticity in intrinsically aged mice. Female hairless mice were fed a control diet or a collagen hydrolysate-containing diet for 12 wk. Stratum corneum water content and skin elasticity were gradually decreased in chronologically aged control mice. Intake of collagen hydrolysate significantly suppressed such changes. Moreover, we used DNA microarrays to analyze gene expression in the skin of mice that had been administered collagen hydrolysate. Twelve weeks after the start of collagen intake, no significant differences appeared in the gene expression profile compared with the control group. However, 1 wk after administration, 135 genes were upregulated and 448 genes were downregulated in the collagen group. This suggests that gene changes preceded changes of barrier function and elasticity. We focused on several genes correlated with functional changes in the skin. Gene Ontology terms related to epidermal cell development were significantly enriched in upregulated genes. These skin function-related genes had properties that facilitate epidermal production and differentiation while suppressing dermal degradation. In conclusion, our results suggest that altered gene expression at the early stages after collagen administration affects skin barrier function and mechanical properties. Long-term oral intake of collagen hydrolysate improves skin dysfunction by regulating genes related to production and maintenance of skin tissue.

A novel mechanism for improvement of dry skin by dietary milk phospholipids: Effect on epidermal covalently bound ceramides and skin inflammation in hairless mice

BACKGROUND

Dietary milk phospholipids (MPLs) increase hydration of the stratum corneum and reduced transepidermal water loss (TEWL) in hairless mice fed a standard diet. However, the mechanism by which MPLs improve skin barrier functions has yet to be established.

OBJECTIVE

This study was designed to examine the mechanism by which MPLs may affect covalently bound ceramides and markers of skin inflammation and improve the skin barrier defect in hairless mice fed a magnesium-deficient (HR-AD) diet.

METHODS

Four-week-old female hairless mice were randomized into four groups (n=10/group), and fed a standard (control) diet, the HR-AD diet, the HR-AD diet supplemented with either 7.0 g/kg MPLs (low [L]-MPL) or 41.0 g/kg MPLs (high [H]-MPL).

RESULTS

Dietary MPLs improved the dry skin condition of hairless mice fed the HR-AD diet. MPLs significantly increased the percentage of covalently bound ω-hydroxy ceramides in the epidermis, and significantly decreased both thymus and activation-regulated chemokine (TARC) mRNA and thymic stromal lymphopoietin (TSLP) mRNA levels in skin, compared with the HR-AD diet. Furthermore, the MPL diets significantly decreased serum concentrations of immunoglobulin-E, TARC, TSLP, and soluble P-selectin versus the HR-AD diet.

CONCLUSION

Our study showed for the first time that dietary MPLs may modulate epidermal covalently bound ceramides associated with formation of lamellar structures and suppress skin inflammation, resulting in improved skin barrier function.

Effects of Egg Shell Membrane Hydrolysates on UVB-radiation-induced Wrinkle Formation in SKH-1 Hairless Mice

This study was conducted to examine the effect of egg shell membrane hydrolysates (ESMH) on wrinkle, UV, and moisture protection for cosmetic use. ESMH were fragmented as whole ESMH (before fractioning), Fraction I (> 10 kDa), Fraction II (3-10 kDa), and Fraction III (< 3 kDa). In order to test whether fractionated ESMH can be used for functional cosmetic materials, we examined not only the level of hyaluronic acid and collagen production, but also the MMP-1 activity using a HaCaT and CCD-986Sk cell line. Our study treated each sample of fractionated ESMH with different concentrations (0.01, 0.1, 1 mg/mL). In our in vivo research, we used hairless mice that had been exposed to UV-B to induce wrinkles for 7 wk, then applied Fraction I to the treatment group for 5 wk and then tested skin thickness, minimum erythema dose and moisture content. In addition, Fraction I was high in collagen and HA biosynthesis and it was better than TGF-β in improving of the skin. When TNF-α caused MMP-1 activity in the CCD-986Sk cells, the whole ESMH and Fraction I proved to be effective in hindering the induction of collagenase depending on the concentration, and also showed outstanding effects in the suppression of skin aging. We found that the treatment group mice’s UV-B radiation-induced skin damage was largely mitigated compared to that of the non-treatment group mice. Thus, we have concluded that EMSH helps to mitigate UV-B radiation-induced wrinkles, collagen, HA, MMP-1 activity and can be used for functional cosmetic materials.