Effects of Ingestion of Collagen Peptide on Collagen Fibrils and Glycosaminoglycans in the Dermis

The evidence from in vitro primary fibroblasts and a randomized, double-blind, placebo-controlled clinical trial of tuna collagen peptides intake on skin health

BACKGROUND

Collagen peptides from various sources demonstrate benefits in health and well-being both in vitro and in clinical trials. However, there is a scarce study of collagen peptides from Tuna on skin health.

AIMS

To investigate the impact of collagen peptides derived from Tuna (Katsuwonus pelamis and Thunnus albacares) on skin health, utilizing in vitro biological studies and a randomized controlled trial.

METHODS

In vitro biological studies on human dermal primary fibroblasts were evaluated in terms of collagen and elastin synthesis and senescent cell inhibition. A randomized, placebo-controlled, double-blind clinical trial was conducted on 72 women who were randomly assigned to receive either tuna collagen peptides (n = 36) or a placebo (n = 36) orally for 8 weeks and 2 weeks post-ingestion by measuring skin hydration, transepidermal water loss (TEWL), skin elasticity, and skin density.

RESULTS

In vitro biological effects demonstrated dose-dependent positive results in increasing collagen and elastin synthesis and reducing senescent cells. The effects on collagen and senescent cells plateaued at high concentrations. A clinical trial showed that the test group experienced a significant increase in skin hydration, elasticity, and density, along with a decrease in TEWL compared to the baseline. The test and placebo groups showed statistically significant differences at 8 weeks for all parameters except for the TEWL at the face. All positive effects were substantially retained even after 2 weeks of discontinuation.

CONCLUSIONS

These findings demonstrate the significant potential of tuna collagen peptides to promote human skin health, warranting further investigation as a potential nutraceutical.

Beneficial Effects of Multi-Micronutrient Supplementation with Collagen Peptides on Global Wrinkles, Skin Elasticity and Appearance in Healthy Female Subjects

INTRODUCTION

With ageing, collagen production slows down, leading to wrinkle appearance and loss of elasticity. Replenishing key structural molecules through oral supplementation is a promising strategy that complements the topical delivery of cosmetic products and creates a holistic skincare regimen. The present study assessed the effectiveness of a food supplement with collagen peptides, vitamins and minerals in improving the quality of the skin and general wellbeing of healthy women.

METHODS

This was an open-label study of 135 women aged between 45 and 65 years. A 3-month treatment phase followed a 4-week washout phase, with visits scheduled at baseline and after each month of treatment. Subjects received three tablets of Richelet Skin Renewal daily. The primary outcome was change from baseline to month 3 in global wrinkles score by expert grader analysis. Secondary outcomes included changes in skin elasticity and other skin attributes, product assessment via self-perception questionnaires and total antioxidant status.

RESULTS

A total of 116 subjects completed the study. The mean global wrinkles score indicated a statistically significant decrease from 5.9 at baseline to 5.0 at month 3 (p < 0.0001), with 83.6% of subjects showing an improvement; significant changes were reported at all intermediate visits. The increase in skin elasticity was also statistically significant (R2 score 0.74 at month 3; p < 0.0001). All subjects (100%) demonstrated significant improvements in skin texture, skin tone evenness, skin radiance and overall skin quality at the month 3 visit.

CONCLUSIONS

The study product achieved statistically significant, noticeable effects on global wrinkles, skin elasticity and a range of skin attributes after 3 months of use in healthy women. These results strengthen the evidence for supplementation of collagen peptides and other micronutrients as an effective component of anti-ageing skincare.

Collagen peptides affect collagen synthesis and the expression of collagen, elastin, and versican genes in cultured human dermal fibroblasts

Background

Collagen is one of the major proteins of the skin and it is particularly important for its strength and resilience. Skin aging is a natural process that is characterized by the decrease and fragmentation of collagen in the dermis. Oral supplementation with collagen peptides has been clinically shown to have a positive effect on the skin condition. However, the mechanisms of aging-related changes synthesized by cells exposed to collagen are currently not well understood. Therefore, in this in vitro study, the mechanisms associated with collagen, elastin, and versican in human dermal fibroblasts were investigated after exposure to collagen peptides.

Methods

The effects of different concentrations of collagen peptides on cell viability and metabolism were analyzed. For gene expression analysis, human dermal fibroblasts were treated with collagen peptides. This was then followed by RNA extraction and DNA synthesis. Gene expressions of collagen type 1 (COL1A1), elastin (ELN), and versican (VCAN) were quantified by quantitative reverse transcription polymerase chain reaction (RT-qPCR). In addition, collagen levels were analyzed by confocal scanning laser microscopy using immunostaining.

Results

Collagen peptides tested in the study increased the expression of the relevant COL1A1, ELN, and VCAN genes in human dermal fibroblasts (p < 0.005). Furthermore, confocal microscopy showed increased collagen expression in the dermal fibroblast culture after treatment with the collagen peptides (p < 0.005).

Conclusion

These data provide cell-based evidence for the beneficial effects of exposure to collagen peptides on the skin's collagen content and on the molecules that provide firmness and elasticity. This may support the hypothesis that collagen peptides are important for maintaining extracellular matrix (ECM) structure and skin regeneration.

Ultrastructural analysis of throat dermal tissue and chromatophore components in the threespine stickleback (Gasterosteus aculeatus)

The threespine stickleback (Gasterosteus aculeatus) is an important model for studying the evolution of nuptial coloration, but histological analyses of color are largely lacking. Previous analyses of one nuptial coloration trait, orange-red coloration along the body, have indicated carotenoids are the main pigment producing this color. In addition, recent gene expression studies found variation in the correlates of throat coloration between the sexes and between populations, raising the possibility of variation in the mechanisms underlying superficially similar coloration. We used transmission electron microscopy (TEM) to investigate the histological correlates of color in the throat dermal tissue of threespine stickleback from Western North America, within and between sexes, populations, and ecotypes. Ultrastructural analysis revealed carotenoid-containing erythrophores to be the main chromatophore component associated with orange-red coloration in both males and females across populations. In individuals where some darkening of the throat tissue was present, with no obvious orange-red coloration, erythrophores were not detected. Melanophore presence was more population-specific in expression, including being the only chromatophore component detected in a population of darker fish. We found no dermal chromatophore units within colorless throat tissue. This work confirms the importance of carotenoids and the erythrophore in producing orange-red coloration across sexes, as well as melanin within the melanophore in producing darkened coloration, but does not reveal broad histological differences among populations with similar coloration.

Oral intake of collagen peptide NS improves hydration, elasticity, desquamation, and wrinkling in human skin: a randomized, double-blinded, placebo-controlled study

Collagen hydrolysate, which contains bioactive peptides, is used as a dietary supplement for the refinement of elasticity, hydration, desquamation, and wrinkling of aging human skin. Here, we conducted a double-blind, randomized, and placebo-controlled oral administration study on the effects of a collagen peptide (CPNS) containing dipeptides, including Gly-Pro and Pro-Hyp, on skin wrinkling, desquamation, elasticity, and hydration. Our results show that an intake of 1650 mg per day of CPNS for 12 weeks had beneficial effects on skin health in a cohort of women aged from 30 to 60 years (n = 100). Compared with the placebo group, skin desquamation, hydration, skin wrinkling, and elasticity were significantly improved after 4, 4, 12, and 12 weeks of administration, respectively. In a safety test of CPNS ingestion, none of the participants showed any side effects during the clinical study period. These results demonstrate that the low molecular weight bioactive peptides contained in CPNS, such as Gly-Pro and Pro-Hyp, exert positive effects on skin hydration, elasticity, desquamation, and wrinkling.

Collagen Structure, Synthesis, and Its Applications: A Systematic Review

Resorbable collagen has been utilized to treat wounds, close graft, and tooth extraction sites, and enhance recovery. Collagen-based membranes are also used as barriers in periodontal and implant therapy to limit epithelial migration and allow cells with the regenerative capacity to fill the problem area. This systematic review was carried out to analyze the studies focusing on collagen structure, synthesis, and its applications. A detailed and extensive search was performed with the help of the keywords "collagen structure", "collagen synthesis" and "collagen applications". There was extensive literature search in reliable and authentic databases like PubMed, Scopus, Web of Sciences, Ovidsp, and Cochrane library to obtain papers focusing on collagen structure, synthesis, and applications. During the systematic review, data were obtained concerning the following parameters. Type of study, nature of aim of the study, size of the sample in the study, gender and age of the subjects included in the study, prevalence of skin diseases where collagen was used for treatment, dose of collagen used, form in which collagen was used, the origin of collagen used, analysis of different variables, structure, and synthesis of collagen. Twenty-two studies were included in this systematic review. The studies discussed the structure, synthesis, and applications of collagen in treatment. In studies focusing on the application of collagen supplements, most of the study subjects were females (68.3%). The study subjects included both healthy and unhealthy subjects. The study subjects were divided into two categories. One category was the intervention group, while another group was the placebo group. Collagen was administered in hydrolysate form (90%) in some studies, bovine form (2.3%), and porcine form (3.4%) in other studies. Collagen supplementation was found to provide better results in both healthy and unhealthy effects in improving the health of skin, cornea, bone, periodontium, face, etc. It can be concluded that collagen is an integral part of the body. The application of collagen supplements can be pretty effective in maintaining the proper health of several important structures of the body like skin, face, cornea, nails, periodontium, etc. Thus, a detailed study of the molecular structure of collagen and genes associated with each type of collagen is essential for further research and treatment of collagen-associated disorders.

Targeted nutritional supplementation for telogen effluvium: Multicenter study on efficacy of a hydrolyzed collagen, vitamin., and mineral-based induction and maintenance treatment

Background:

The condition of the hair is closely related to the nutritional state. Normal supply, uptake, and transport of nutrients are of fundamental importance in tissues with a high biosynthetic activity such as the hair follicle.

Objective:

The objective of the study was to evaluate the efficacy of a nutritional-based induction and maintenance treatment for telogen effluvium formulated with a combination of hydrolyzed collagen, amino acids, vitamins, and minerals.

Patients and Methods:

The clinical studies were conducted with each nutritional treatment individually, and both in sequential combination. Anagen/telogen ratio, hair density, and tolerability of treatment were assessed at baseline, 4 weeks of induction therapy, and another 12 weeks of maintenance treatment. Trichogram results showed a significant improvement of the anagen/telogen ratio between baseline and final visit at 16 weeks, with an increase of hair in anagen and a reduction of hair in telogen. Furthermore, a significant increase was observed in hair density. The effect size of the combination treatment was higher than that of each of the two products used separately as monotherapy.

Conclusions:

The study results provide a proof of concept for targeted nutritional supplementation for the treatment of telogen effluvium, with a special emphasis on the role of collagen, besides specific amino acids, vitamins, and minerals.

Oral Intake of Enzymatically Decomposed AP Collagen Peptides Improves Skin Moisture and Ceramide and Natural Moisturizing Factor Contents in the Stratum Corneum

The stratum corneum (SC) is the outermost layer of the epidermis and plays an important role in maintaining skin moisture and protecting the skin from the external environment. Ceramide and natural moisturizing factor (NMF) are the major SC components that maintain skin moisture. In this study, we investigated whether the oral intake of enzymatically decomposed AP collagen peptides (APCPs) can improve skin moisture and barrier function by assessing changes in the ceramide and NMF contents in the SC after APCP ingestion with the aim to develop a skin functional food. Fifty participants orally ingested APCP (1000 mg) or placebo for 12 weeks, and then, skin hydration and skin texture were evaluated. SC samples were collected to analyze skin scaling, ceramide, and NMF contents. Participants in the APCP group exhibited improved skin moisture content by 7.33% (p = 0.031) and roughness by -4.09% (p = 0.036) when compared with those in the placebo group. NMF content; the amounts of amino acids (AA), including glycine and proline; and AA derivatives were significantly increased in the APCP group (31.98 μg/mg protein) compared to those in the placebo group (-16.01 μg/mg protein) (p = 0.006). The amounts of total ceramides and ceramide subclasses were significantly higher in the APCP group than in the placebo group (p = 0.014). In conclusion, our results demonstrate that APCP intake improves skin moisture and increase the ceramide and NMF contents in the SC, thereby enhancing the skin barrier function.

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.

Alternative method for oral administration of insoluble toxins to rats. A prenatal study of L-mimosine

L-mimosine is a compound found in Leucaena leucocephala, that is used as animal feed due to its high protein content, but it can also cause intoxication. Due to its low solubility in organic and aqueous solvents, its administration in laboratory animals is difficult, especially in delicate periods such as pregnancy. Thus, to circumvent such problems, this study proposes a stress-free form of oral administration with gelatin tablets with flavoring (meat broth) for 14 consecutive days of the gestational period (GD06 to GD20). For that, 17 pregnant Wistar rats divided into 3 groups were used: control (CO; n = 5) not treated; gelatin (GEL; n = 6), which received a gelatin tablet with flavoring; and gelatin with flavoring added 140 mg/kg of L-mimosine (GM; n = 6). All animals received feed and water ad libitum. The parameters analyzed were body weight gain, water and feed consumption, serum biochemistry, blood count and reproductive indices. Among these, only the real and total weight gains of dams showed statistically significant differences, with a decrease in the group GM. Thus, we could observe that flavored gelatin was an efficient and effective administration method to insoluble compounds and long-term administration to pregnant rats, with quick adaptation and without refusal by the animals. In addition, we could observe a direct effect of L-mimosine on the animals' weight gain; however, the dose administered was not sufficient to confer maternal and fetal toxicity.

Effects of Pig Skin Collagen Supplementation on Broiler Breast Meat

This study aimed to enhance the quality of broiler breast meat by adding pig skin collagen to feed. A total of 50 Ross 308 broilers were classified according to the following feeding regime for two weeks: basal diet (NC), basal diet+0.1% fish collagen (PC), basal diet+0.1% pig skin collagen (T1), basal diet+0.5% pig skin collagen (T2), and basal diet+1.0% pig skin collagen (T3). The moisture content was the highest in the PC group, and the protein content was the lowest in the T1 group (p<0.05). The fat content was higher in the T1 and PC groups, whereas the ash content was higher in the T3 group (p<0.05). Drip loss was the highest in the NC group and the lowest in the T2 group (p<0.05). Lightness was low in groups T2 and T3, redness was low in groups T2 and PC, and yellowness was low in groups T1, T2, and PC (p<0.05). The collagen content of the chicken breast was the highest in the T3 group, and that of the skin was the highest in the T1 group (p<0.05). The texture characteristics of springiness, cohesiveness, chewiness, and hardness were the highest in the T3 group (p<0.05). In conclusion, the supplementation of a broiler diet with pig skin collagen was found to increase the collagen content of the breast meat, indicating the improved quality of the broiler breast meat.

Anti-aging effect of an oral disintegrating collagen film: a prospective, single-arm study

BACKGROUND

As the average life expectancy increases, skin aging and wrinkles due to photoaging have gained attention. Collagen is closely involved in the process of skin aging. Among the potential methods of drug delivery to the skin, oral disintegrating films show promise for their ability to bypass the loss of active components that is typical of drug absorption via oral administration. This study was conducted to investigate the effect of an oral disintegrating collagen film on skin aging.

METHODS

We performed a prospective, single-arm study in a cohort of 22 women to assess the anti-aging effect of a novel oral disintegrating film containing collagen applied daily over a 12-week period. We measured the clinical indicators of skin integrity and performed immunofluorescence and high-performance liquid chromatography analyses of an ex vivo oral mucosa model to compare the absorption rates of collagen films and conventional oral tablets via the mucosa.

RESULTS

We found that the oral disintegrating collagen film reduced skin wrinkle depth and number and significantly increased skin elasticity and density.

CONCLUSIONS

The novel mode of delivery of collagen via oral disintegrating films has a clinically potential anti-aging efficacy and is safe and convenient for daily use.

Water retention capabilities of collagen, gelatin and peptide as studied by IR/QCM/RH system

In this study, water retention properties of triple helix collagen, gelatin (separated single chains) and peptide (broken peptide fragments) were studied by using IR micro-spectroscopy equipped with a relative humidity (RH) control system and quartz crystal microbalance (QCM). Adsorbed water ratios (wt%) are found to be in the order of collagen, gelatin and peptide (at about RH = 60%, 22 wt% for collagen, 14 wt% for gelatin and 9 wt% for peptide). Free water molecules with longer H bonds are the major adsorbed water species for collagen, gelatin and peptide. IR band shifts and changes in normalized band areas of functional groups are generally larger for collagen than gelatin and peptide, indicating larger interactions of water molecules with functional groups such as aliphatic CH₂, CH₃, amides, COO^- and C-O for collagen. Relations between normalized band areas show that water molecules are interacting with aliphatic CH species and C-O bonds of collagen. Since the fibril structures of collagen triple helices are reported to be cross-linked by sugars, water molecules can be attracted to polar C-O bonds of sugars linking collagen triple helices in fibrils and they are interacting with adjacent aliphatic CH side chains on the surface of fibrils.

Collagen formula with Djulis for improvement of skin hydration, brightness, texture, crow's feet, and collagen content: A double-blind, randomized, placebo-controlled trial

BACKGROUND

The efficacy of Djulis for skin care is currently based on cellular or animal models, and the clinical aspect is not in place.

AIM

This clinical study is to investigate the synergistic effect of fish collagen and Djulis (Chenopodium formosanum Koidz.) for improvement of skin parameters. We used the combination of hydrolyzed collagen and Djulis to develop a new functional formula for skin improvement.

PATIENTS/METHODS

Fifty volunteers were randomly allocated (in a 1:1 ratio) to the placebo or collagen drink group. Volunteers were required to consume a 50 mL of a collagen drink or placebo drink daily for 8 weeks. For measurements, the indexes of skin conditions were measured at the baseline and 4 and 8 weeks.

RESULTS

The improvements of skin hydration, brightness, crow's feet, texture, wrinkles, pores, spots, and collagen content after 8 weeks in collagen group were 17.8%, 5.4%, 14.9%, 9.9%, 29.3%, 10.4%, 9.9%, and 22.3%, respectively. Noticeably, over 68% of subjects got improved for their skin parameters after 8-week intake of collagen drink. The improvement levels indicated competitive skin improvement effects in comparison with previous studies.

CONCLUSION

This clinical study demonstrates the synergistic effect of fish collagen and Djulis (the main components) for the substantial improvements in hydration, brightness, crow's feet, texture, wrinkles, pores, surface spots, and collagen content in skin. The collagen drink comprehensively improved skin parameters for most subjects after 4-week intake and manifested competitive efficiency in comparison with other similar studies. We convince that the collagen drink may delay skin aging process and improve skin aging parameters.

Collagen supplementation for skin health: A mechanistic systematic review

BACKGROUND

Over the last decade, many researchers tried to evaluate the effects of collagen supplements on skin aging and surprisingly revealed that the interventions improved skin aging parameters without any inconsistency.

AIM

This systematic review assesses the literature regarding the effects of collagen supplements on skin health parameters in healthy and patient subjects, focusing on mechanisms of action.

METHODS

At the first step of search in the databases, 9057 items were obtained. After removal of duplicate items, 6531 publications remained. Further screening by title and/or abstract resulted in removal of 6500 items. Finally, full texts of the 31 remained items were assessed for eligibility and 10 publications were included in this review.

RESULTS

The evidences obtained from these systematic reviews indicated that oral administration of intact or hydrolyzed collagen improves clinical manifestation of skin health. Almost all of the included studies reported the beneficial effects of collagen supplementation, and no inconsistencies have been seen in this regard between studies.

CONCLUSIONS

In this systematic review, three different mechanisms of action were clarified for the intervention. Direct effects of collagen peptides on fibroblasts, M2-like macrophages, and oral tolerance-related mechanisms are the possible mechanisms for the beneficial effects of collagen supplementation.

Efficacy of a collagen hydrolysate and antioxidants-containing nutraceutical on metrics of skin health in Indian women

BACKGROUND

The skin's aging process involves a decreased biosynthesis of extracellular matrix proteins (predominantly collagen) compounded by damage from environmental and intrinsic stressors. The Indian population is susceptible to skin damage given its geography and increasing urbanization or a genetic disposition. Previous studies have investigated nutrients such as collagen peptides, vitamins and phytonutrient-rich botanical extracts for their individual benefits on skin.

AIMS

This study examined the collective effect of a proprietary blend of these nutrients (in Nutrova Collagen+Antioxidants; NCA) on skin parameters, which has not been previously studied, especially in an Indian context.

PATIENTS/METHODS

34 healthy, Indian women (mean age = 39.5 years) were given a placebo daily for 30 days to establish a baseline, followed by NCA for two intervals of 30 days. 3D image reconstruction allowed the analysis of skin topography and blemishes. Instrumental measurements also included skin firmness, elasticity, hydration, and transepidermal water loss. Clinical evaluation was used to grade blemishes, wrinkles and periorbital hyperpigmentation.

RESULTS

Based on instrumental evaluation, NCA significantly reduced wrinkle width, open pores, skin roughness, and the colour of hyperpigmented blemishes, while improving skin hydration, firmness and barrier function from baseline to Day 30 and Day 60. NCA also increased elasticity at Day 30. Clinical evaluation showed that periorbital hyperpigmentation and wrinkles reduced significantly.

CONCLUSION

NCA is effective for improving overall skin health in Indian women. These results show that targeted nutrient supplementation can improve skin health and further research over extended durations is merited.

Oral Collagen Drink for Antiaging: Antioxidation, Facilitation of the Increase of Collagen Synthesis, and Improvement of Protein Folding and DNA Repair in Human Skin Fibroblasts

This work unveils a fish collagen drink for improvement of skin aging. Previous studies frequently discussed the skin aging from the angle of the representative characteristics of collagen loss and the oxidative-induced expression of proteolytic enzymes matrix metalloproteinases (MMPs), but few groups comprehensively investigated the efficacy of oral hydrolyzed collagen for enhancing protein folding and DNA repair as well as improving notable cell behaviors. To delineate the broad perspective on delaying skin aging, we inspected the collagen drink-treated fibroblast cells from the molecular and cellular aspects. The results show that the collagen drink could perform the compact antiaging effects on ROS inhibition, the facilitation of the synthesis of extracellular matrix (ECM) proteins, the increase of mitochondrial activity, and improvement of the gene expression regarding correct protein folding, DNA mismatch repair (MMR) and base excision repair (BER). Although the experimental results are built on the cellular models, we believe that the positive outcomes can provide more details on the influence of oral hydrolyzed collagen supplement for antiaging. In short, we have successfully proved that the synergistic effect of the collagen drink could not only reduce the oxidative damage but also ameliorate the cell functionality to compensate the harmful effects induced by UVA.

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.

Effects of Different Vitamin C–Enriched Collagen Derivatives on Collagen Synthesis

Nutritional strategies to improve connective tissue collagen synthesis have garnered significant interest, although the scientific validity of these interventions lags behind their hype. This study was designed to determine the effects of three forms of collagen on N-terminal peptide of procollagen and serum amino acid levels. A total of 10 recreationally active males completed a randomized double-blinded crossover design study consuming either placebo or 15 g of vitamin C–enriched gelatin or hydrolyzed collagen (HC), or gummy containing equal parts of gelatin and HC. Supplements were consumed 1 hr before 6 min of jump rope. Blood samples were collected immediately prior to supplement consumption and 4 hr after jump rope. A subset of blood samples (n = 4) was collected for amino acid analysis 1 hr after ingestion. Consumption of an equivalent dose of each supplement increased amino acids in the circulation similarly across all interventions. N-terminal peptide of procollagen levels tended to increase ∼20% from baseline in the gelatin and HC interventions but not the placebo or gummy. These results suggest that vitamin C–enriched gelatin and HC supplementation may improve collagen synthesis when taken 1 hr prior to exercise. However, large variability was observed, which precluded significance for any treatment.

Preparation and Evaluation of Peptides with Potential Antioxidant Activity by Microwave Assisted Enzymatic Hydrolysis of Collagen from Sea Cucumber Acaudina Molpadioides Obtained from Zhejiang Province in China

The present study was focused on the preparation and characterization of the antioxidant peptides by microwave-assisted enzymatic hydrolysis of collagen from sea cucumber Acaudina molpadioides (ASC-Am) obtained from Zhejiang Province in China. The results exhibited the effects of microwave irradiation on hydrolysis of ASC-Am with different protease. Neutrase was selected from the four common proteases (papain, pepsin, trypsin, and neutrase) based on the highest content and DPPH scavenging activity of hydrolysate Fa (Molecular weight < 1 kDa). The content and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity of Fa obtained by hydrolysis of neutrase increased by 100% and 109% respectively at a microwave power of 300 W compared with no microwave irradiation. Five subfractions were obtained after performing the gel filtration chromatography, and the Fa.2 exhibited the highest DPPH scavenging activity. The amino acid analysis showed that the contents of Glutamic acid, Alanine, Tyrosine, and Phenylalanine in fraction Fa.2 increased significantly, but an obvious decrease in the content of Glycine was observed compared to Fa. Four peptides (Fa.2-A, Fa.2-B, Fa.2-C, and Fa.2-D) were purified from Fa.2 by high performance liquid chromatography, and Fa.2-C showed the highest DPPH scavenging activity. The sequence of Fa.2-C was identified as Phenylalanine-Leucine- Alanine-Proline with a half elimination ratio (EC₅₀) of 0.385 mg/mL. The antioxidant activity of Fa.2-C was probably attributed to the small molecular sizes and the presence of hydrophobic amino acid residues in its sequence. This report provided a promising method for the preparation of antioxidant peptides from collagen for food and medicinal purposes.

Orally administered collagen peptide protects against UVB-induced skin aging through the absorption of dipeptide forms, Gly-Pro and Pro-Hyp

Collagen hydrolysate is a well-known nutritional supplement for the improvement of healthy skin. Here, collagen peptide NS (CPNS) from fish scale was prepared, and its physicochemical properties were investigated. Gly-Pro was revealed as a representative low molecular weight peptide of CPNS, by performing prep-HPLC and LC-MS/MS. CPNS treatment attenuated matrix metalloproteinase-1 production and increased the synthesis of type 1 procollagen in HDF cells. After orally administering CPNS to rats, the plasma concentrations of Gly-Pro and Pro-Hyp increased dramatically. To examine the protective effects of CPNS against ultraviolet B (UVB)-induced photoaging in vivo, the dorsal skins of hairless mice were exposed to UVB and supplemented with CPNS for 12 weeks. The CPNS consumption significantly attenuated UVB-induced wrinkle formation, transepidermal water loss, and epidermis thickness, and increased skin hydration. Collectively, these results suggest that bioactive peptides of CPNS, Gly-Pro and Pro-Hyp, exert beneficial effects on skin health.

Enhancing Skin Health: By Oral Administration of Natural Compounds and Minerals with Implications to the Dermal Microbiome

The history of cosmetics goes back to early Egyptian times for hygiene and health benefits while the history of topical applications that provide a medicinal treatment to combat dermal aging is relatively new. For example, the term cosmeceutical was first coined by Albert Kligman in 1984 to describe topical products that afford both cosmetic and therapeutic benefits. However, beauty comes from the inside. Therefore, for some time scientists have considered how nutrition reflects healthy skin and the aging process. The more recent link between nutrition and skin aging began in earnest around the year 2000 with the demonstrated increase in peer-reviewed scientific journal reports on this topic that included biochemical and molecular mechanisms of action. Thus, the application of: (a) topical administration from outside into the skin and (b) inside by oral consumption of nutritionals to the outer skin layers is now common place and many journal reports exhibit significant improvement for both on a variety of dermal parameters. Therefore, this review covers, where applicable, the history, chemical structure, and sources such as biological and biomedical properties in the skin along with animal and clinical data on the oral applications of: (a) collagen, (b) ceramide, (c) β-carotene, (d) astaxanthin, (e) coenzyme Q10, (f) colostrum, (g) zinc, and (h) selenium in their mode of action or function in improving dermal health by various quantified endpoints. Lastly, the importance of the human skin microbiome is briefly discussed in reference to the genomics, measurement, and factors influencing its expression and how it may alter the immune system, various dermal disorders, and potentially be involved in chemoprevention.

Improvement of dermal parameters in aged skin after oral use of a nutrient supplement

Purpose

Skin aging is a progressive and degenerative process caused by a decrease in the physiological functions of the skin tissue. In addition, environmental factors as well as concomitant diseases and lifestyle (nutrition, sedentary lifestyle, smoking, etc) negatively impact the aging process. An association between oral administration of collagen peptides combined with vitamin C and extracts of Hibiscus sabdariffa and Aristotelia chilensis (Delphynol^®) (Eximia Firmalize Age complex^®) on dermal thickness was studied and the improvement in aging signs was evaluated.

Patients and methods

Female adult patients received an oral nutritional supplement containing collagen peptides, vitamin C, H. sabdariffa, and A. chilensis (Delphynol) in a sachet and were instructed to consume 1 sachet diluted in 200 mL of water once daily for 12 weeks. They were evaluated clinically, by high frequency ultrasound and cutometry.

Results

There was a significant improvement of firmness and elasticity and an increase in dermal thickness by ultrasound after 3 months of use.

Conclusion

The association of collagen peptides, vitamin C, H. sabdariffa and A. chilensis (Delphynol) could improve the signs of dermal skin aging.

The promise of marine molecules as cosmetic active ingredients

The marine environment represents an underexploited resource for the discovery of novel products, despite its high level of biological and chemical diversity. With increasing awareness of the harmful effects of chronic ultraviolet exposure, and a universal desire to improve cosmetic appearance, the market for new cosmetic ingredients is growing, and current trends have generated a greater demand for products sourced from the environment. A growing number of novel molecules from marine flora and fauna exhibit potent and effective dermatological activities. Secondary metabolites isolated from macroalgae, including carotenoids and polyphenols, have demonstrated antioxidant, anti-ageing and anti-inflammatory activities. In addition, marine extremophilic bacteria have recently been shown to produce bioactive exopolymeric molecules, some of which have been commercialized. Available data on their activities show significant antioxidant, moisturizing and anti-ageing activities, but a more focussed investigation into their mechanisms and applications is required. This review surveys the reported biological activities of an emerging and growing portfolio of marine molecules that show promise in the treatment of cosmetic skin problems including ultraviolet damage, ageing and cutaneous dryness.

Collagen peptides modulate the metabolism of extracellular matrix by human dermal fibroblasts derived from sun-protected and sun-exposed body sites

Clinical data published in recent years have demonstrated positive effects of collagen hydrolysate (CH) on skin aging clinical signs. CH use as food supplement has a long history; however, few studies have addressed the underlying purpose of CH on the cellular and molecular biology of skin cells that could elucidate clinical improvement findings. Wide diversity of characteristics has been reported for dermal fibroblasts derived from different body sites and it is unknown whether collagen peptides could modulate differently cells from chronological aged and photoaged skin areas. This study investigated the influence of CH on the extracellular matrix metabolism and proliferation of human dermal fibroblasts (HDFs) derived from chronological aged (sun-protected) and photoaged (sun-exposed) body sites. CH treatment did not affect cellular proliferation of either cell cultures, but notably modulated cell metabolism in monolayer model, increasing the content of dermal matrix precursor and main protein, procollagen I and collagen I, respectively. These effects were confirmed in the human dermal equivalent model. The increase in collagen content in the cultures was attributed to stimulation of biosynthesis and decreased collagen I metabolism through inhibition of metalloproteinase activity (MMP) 1 and 2. Modulation of CH in dermal metabolism did not differ between cells derived from sun-protected and sun-exposed areas, although lower concentrations of CH seemed to be enough to stimulate sun-exposed-derived HDFs, suggesting more pronounced effect in these cells. This study contributes to understanding the biological effects of CH on skin cells and viability of its use as a functional ingredient in food supplements.

Improvement of skin condition by oral administration of collagen hydrolysates in chronologically aged mice

BACKGROUND

Collagen hydrolysates (CHs) have been demonstrated to have positive effects on skin photoaging by topical application or oral ingestion. However, there has been little research on their influence on skin chronological aging. In this study, 9-month-old female ICR mice were given normal AIN-93M diets containing CHs (2.5, 5 and 10% w/w) from Nile tilapia scale.

RESULTS

After 6 months, the collagen content and antioxidant enzyme (superoxide dismutase and glutathione peroxidase) activities increased significantly (P < 0.05), while the survival rate, viscera indices and contents of moisture, fat and non-collagenous protein in skin did not change (P > 0.05). The color, luster and quantity of hair were obviously ameliorated. Moreover, the structure of epidermis and dermis, the density and distribution of collagen fibers and the ratio of type I to type III collagen were improved in a dose-dependent manner as shown by histochemical staining.

CONCLUSION

Oral ingestion of CHs increased the collagen content and antioxidant enzyme activities and improved the appearance and structure of skin. These results suggest the potential of CHs as an anti-skin-aging ingredient in nutraceuticals or functional foods. © 2016 Society of Chemical Industry.

An Insight into the Changes in Skin Texture and Properties following Dietary Intervention with a Nutricosmeceutical Containing a Blend of Collagen Bioactive Peptides and Antioxidants

BACKGROUND

Skin aging is a multifactorial phenomenon which causes alterations in skin physiological functions and, most visibly, phenotypic changes. In particular, during the aging process, hyaluronic acid, collagen, and elastin fibers undergo structural and functional changes.

AIMS

This study aimed to give an insight into the photo-protective benefits and efficacy of an oral liquid nutricosmeceutical containing collagen bioactive peptides and antioxidants to counteract the signs of aging.

METHODS

A double-blind, randomized, placebo-controlled clinical trial was conducted by an independent esthetic clinic on 120 healthy volunteer subjects for 90 days. Subjects were divided into 2 groups: 60 subjects consumed 1 bottle (50 mL) of the nutricosmeceutical daily and the other 60 consumed 1 bottle (50 mL) of the placebo. Outcome measures were related to skin elasticity (expressed as Young's elasticity modulus) and skin architecture (histological analysis). In addition, the subjects recruited in this study underwent observational assessments through self-assessment questionnaires.

RESULTS AND CONCLUSIONS

Overall, we demonstrated a significant increase in skin elasticity (+7.5%), p ≤ 0.001 and an improvement in skin texture after daily oral consumption of the nutricosmeceutical. We also obtained a positive patient feedback through the self-assessment questionnaires. Taken together these results show that this nutricosmeceutical supplement may have photo-protective effects and help improve skin health.

Daily oral consumption of hydrolyzed type 1 collagen is chondroprotective and anti-inflammatory in murine posttraumatic osteoarthritis

Osteoarthritis (OA) is a degenerative joint disease for which there are no disease modifying therapies. Thus, strategies that offer chondroprotective or regenerative capability represent a critical unmet need. Recently, oral consumption of a hydrolyzed type 1 collagen (hCol1) preparation has been reported to reduce pain in human OA and support a positive influence on chondrocyte function. To evaluate the tissue and cellular basis for these effects, we examined the impact of orally administered hCol1 in a model of posttraumatic OA (PTOA). In addition to standard chow, male C57BL/6J mice were provided a daily oral dietary supplement of hCol1 and a meniscal-ligamentous injury was induced on the right knee. At various time points post-injury, hydroxyproline (hProline) assays were performed on blood samples to confirm hCol1 delivery, and joints were harvested for tissue and molecular analyses were performed, including histomorphometry, OARSI and synovial scoring, immunohistochemistry and mRNA expression studies. Confirming ingestion of the supplements, serum hProline levels were elevated in experimental mice administered hCol1. In the hCol1 supplemented mice, chondroprotective effects were observed in injured knee joints, with dose-dependent increases in cartilage area, chondrocyte number and proteoglycan matrix at 3 and 12 weeks post-injury. Preservation of cartilage and increased chondrocyte numbers correlated with reductions in MMP13 protein levels and apoptosis, respectively. Supplemented mice also displayed reduced synovial hyperplasia that paralleled a reduction in Tnf mRNA, suggesting an anti-inflammatory effect. These findings establish that in the context of murine knee PTOA, daily oral consumption of hCol1 is chondroprotective, anti-apoptotic in articular chondrocytes, and anti-inflammatory. While the underlying mechanism driving these effects is yet to be determined, these findings provide the first tissue and cellular level information explaining the already published evidence of symptom relief supported by hCol1 in human knee OA. These results suggest that oral consumption of hCol1 is disease modifying in the context of PTOA.

Remodeling of rat stromal-vascular cells to brite/beige adipocytes by prolyl-hydroxyproline

The aim of this study was to determine the effects of prolyl-hydroxyproline (Pro-Hyp) on the proliferation and differentiation of rat stromal-vascular cells (SVCs) being cultured in a medium with (Pro-Hyp group) or without Pro-Hyp (control group). The results showed that there was no significant difference in proliferation rate of SVCs, lipid droplet (LD) diameter or intracellular concentration of triglycerides between two groups. However, the diameter range of LDs in the Pro-Hyp group tended to be smaller than that in the control group. Transmission electron microscopy showed a tendency for increase in the area of mitochondria and decrease in the number of mitochondria in the Pro-Hyp-treated SVCs. The mRNA expression levels of white adipose tissue differentiation markers (Cbp, Fabp and Serpina3k) were significantly lower, but those of the brown adipose tissue differentiation markers (Dio2, Ucp1 and Ucp3) were significantly higher in the Pro-Hyp group than in the control group. Our results suggested that Pro-Hyp can facilitate SVCs to differentiate into “brite/beige” adipocytes.

Collagen peptide ingestion alters lipid metabolism-related gene expression and the unfolded protein response in mouse liver

Ingestion of collagen peptide (CP) elicits beneficial effects on the body, including improvement in blood lipid profiles, but the underlying mechanisms remain unclear. The purpose of this study was to investigate the effects of CP ingestion on the liver, which controls lipid metabolism in the body. Male BALB/cCrSlc mice were bred with the AIN-93M diet containing 14 % casein or the AIN-93M-based low-protein diet containing 10 % casein or a diet containing 6 % casein+4 % CP for 10 weeks (n 12/group). Total, free and esterified cholesterol levels in the blood decreased in the CP group. DNA microarray analysis of the liver revealed that expressions of genes related to lipid metabolic processes such as the PPAR signalling pathway and fatty acid metabolism increased in the CP group compared with the 10 % casein group. The expressions of several genes involved in steroid metabolic process, including Cyp7a1 and Cyp8b1, were decreased, despite being targets of transcriptional regulation by PPAR. These data suggest that lipid metabolism in the liver is altered by CP ingestion, and the decrease in blood cholesterol levels in the CP group is not due to enhancement of the steroid metabolic process. On the other hand, expressions of genes related to the unfolded protein response (UPR) significantly decreased at the mRNA level, suggesting that CP ingestion lowers endoplasmic reticulum stress. Indeed, protein levels of phosphorylated inositol-requiring enzyme 1 decreased after CP ingestion. Taken together, CP affects the broader pathways in the liver – not only lipid metabolism but also UPR.

In-depth comparative analysis of the chicken eggshell membrane proteome

The avian eggshell membrane (ESM) is stabilized by extensive cross-linkages, making the identification of its protein constituents technically challenging. Herein, we applied various extraction/solubilization conditions followed by proteomic analysis to characterize the protein constituents of ESM derived from the unfertilized chicken eggs. The egg white and eggshell proteomes (including previous published work) were determined and compared to ESM to identify proteins that are relatively or highly specific to ESM. Merging the results from different extraction/solubilization conditions with various proteomes allowed the identification of 472, 225, and 488 proteins in the ESM, egg white, and eggshell proteomes, respectively. Of these, 163 and 124 proteins were relatively or highly specific to ESM, respectively. GO term analysis of the common proteins and ESM unique proteins generated 8 and 9 significantly enriched functional groups, respectively. Different families of proteins that were identified as ESM-specific included collagens, CREMPs, histones, AvBDs, lysyl oxidase-like 2 (LOXL2), and ovocalyxin-36 (OCX36). These proteins serve as a foundation for the mechanically stable ESM that rests upon the egg white compartment and is a physical barrier against pathogen invasion. Overall, our results highlight the structural nature of the ESM constituents that are relevant to various biomedical applications, such as wound healing.

BIOLOGICAL SIGNIFICANCE

The eggshell membranes (ESM) are a highly resilient double-layered fibrous meshwork that is secreted while the forming egg transits a specialized oviduct segment, the white isthmus. The ESM protects against pathogen invasion and provides a platform for nucleation of the calcitic eggshell (ES). ESM is greatly stabilized by the extensive desmosine, isodesmosine and disulfide cross-linkages which make the identification of its protein constituents by standard proteomic approaches technically challenging. Comparative proteomic analyses of ESM, egg white, and ES proteins showed proteins groups that are relatively or highly specific to ESM. These groups of proteins serve as a foundation for the mechanically stable ESM that rests upon the egg white compartment and is a physical barrier against pathogen invasion. These features are essential for eggshell quality and for the prevention of pathogen invasion which reinforce food safety of the table egg.

Ingestion of bioactive collagen hydrolysates enhance facial skin moisture and elasticity and reduce facial ageing signs in a randomised double-blind placebo-controlled clinical study

BACKGROUND

Several human studies have demonstrated occurrence of two major collagen peptides, prolyl-hydroxyproline (Pro-Hyp) and hydroxyprolyl-glycine (Hyp-Gly), in human peripheral blood. Some in vitro studies have demonstrated that Pro-Hyp and Hyp-Gly exert chemotaxis on dermal fibroblasts and enhance cell proliferation. Additionally, Pro-Hyp enhances the production of hyaluronic acid by dermal fibroblasts. These findings suggest that the amounts of Pro-Hyp and Hyp-Gly in blood are important factors to show the efficacy of collagen hydrolysates on skin health.

RESULTS

We conducted a randomised double-blind placebo-controlled clinical trial of ingestion of two types of collagen hydrolysates, which are composed of different amounts of the bioactive dipeptides Pro-Hyp and Hyp-Gly, to investigate their effects on the improvement of skin conditions. Improvement in skin conditions, such as skin moisture, elasticity, wrinkles, and roughness, were compared with a placebo group at baseline, and 4 and 8 weeks after the start of the trial. In addition, the safety of dietary supplementation with these peptides was evaluated by blood test. Collagen hydrolysate with a higher content of bioactive collagen peptides (H-CP) showed significant and more improvement than the collagen hydrolysate with a lower content of bioactive collagen peptides (L-CP) and the placebo, in facial skin moisture, elasticity (R2), wrinkles and roughness, compared with the placebo group. In addition, there were no adverse events during the trial.

CONCLUSION

This study demonstrated that the use of the collagen hydrolysate with a higher content of Pro-Hyp and Hyp-Gly led to more improvement in facial skin conditions, including facial skin moisture, elasticity, wrinkles and roughness. © 2016 Society of Chemical Industry.

Anti-Aging Effects of the Hanwoo Leg Bone, Foot and Tail Infusions (HLI, HFI and HTI) on Skin Fibroblast

Many researchers revealed that collagen contribute to maintaining the skin’s elasticity and inhibit wrinkling of skin. Korean native cattle (Hanwoo) bone (leg bone, foot and tail) infusion contains the various inorganic materials, collagen and chondroitin sulfate. All of this, a large quantity of collagen is included in Hanwoo infusion. Therefore, this study emphasized on the effects of collagen in the Hanwoo bone infusion. For the first time, Hanwoo bone infusions were directly added to the media of Human Dermal Fibroblast (NHDF-c) to test anti-aging effects. First, it was identified that growth rate of skin fibroblast was increased. Furthermore, the Hanwoo bone infusion increased a 50% of fibroblast collagen synthesis. Also, suppression of skin fibroblast aging was confirmed by treatment Hanwoo bone infusion. In conclusion, this study demonstrates the effects of infusion made from Hanwoo leg bone, foot and tail on anti-aging, wrinkle inhibiting and skin fibroblast elasticity maintaining. Therefore, this study identified that traditional infusion has effects that are good for skin elasticity.

Determination of bioavailability and identification of collagen peptide in blood after oral ingestion of gelatin

BACKGROUND

Gelatin has long been widely used in foods, pharmaceuticals, cosmetics, and other products. However, there are few reports on its bioavailability and bioavailable forms. In this study, the bioavailability of gelatin was indirectly evaluated by the determining the bioavailability of total hydroxyproline in gelatin using a pharmacokinetic method after oral administration to rats.

RESULTS

The relative and absolute bioavailability of gelatin were 74.12% and 85.97%, respectively. The amino acid profile of plasma indicated that 41.91% of the digested gelatin was absorbed from the intestine in the form of peptide, and there was a good linear correlation between the absorbed amount of an amino acid and its content in gelatin (R(2) = 0.9566). Moreover, 17 types of collagen peptide were purified by multi-step chromatography and identified with ultra-performance liquid chromatography-electrospray ionisation-mass spectrometry.

CONCLUSION

Gelatin had high oral bioavailability. Nearly half of digested gelatin was absorbed from the intestine in the form of various collagen peptides.

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.

Oral ingestion of collagen peptide causes change in width of the perimysium of the chicken iliotibialis lateralis muscle

Skeletal muscle is mainly composed of myofibers and intramuscular connective tissue. Bundles composed of many myofibers, with each myofiber sheathed in connective tissue called the endomysium, are packed in the perimysium, which occupies the vast bulk of the intramuscular connective tissue. The perimysium is a major determination factor for muscle texture. Some studies have reported that collagen peptide (Col-Pep) ingestion improves the connective tissue architecture, such as the tendon and dermis. The present study evaluated the effects of Col-Pep ingestion on the chicken iliotibialis lateralis (ITL) muscle. Chicks were allocated to three groups: the 0.15% or 0.3% Col-Pep groups and a control group. Col-Pep was administered by mixing in with commercial food. On day 49, the ITL muscles were analyzed by morphological observation and the textural property test. The width of the perimysium in the 0.3% Col-Pep group was significantly larger than other two groups. Although scanning electron microscopic observations did not reveal any differences in the architecture of the endomysium, elastic improvement of the ITL muscle was observed as suggested by an increase of the width of perimysium and improved rheological properties. Our results indicate that ingestion of Col-Pep improves the textural property of ITL muscle of chickens by changing structure of the perimysium.

Comparative study of dermal components and plasma TGF-β1 levels in Slc39a13/Zip13-KO mice

Ehlers-Danlos syndrome (EDS) is a group of disorders caused by abnormalities that are identified in the extracellular matrix. Transforming growth factor-β1 (TGF-β1) plays a crucial role in formation of the extracellular matrix. It has been reported that the loss of function of zinc transporter ZRT/IRT-like protein 13 (ZIP13) causes the spondylocheiro dysplastic form of EDS (SCD-EDS: OMIM 612350), in which dysregulation of the TGF-β1 signaling pathway is observed, although the relationship between the dermis abnormalities and peripheral TGF-β1 level has been unclear. We investigated the characteristics of the dermis of the Zip13-knockout (KO) mouse, an animal model for SCD-EDS. Both the ratio of dermatan sulfate (DS) in glycosaminoglycan (GAG) components and the amount of collagen were decreased, and there were very few collagen fibrils with diameters of more than 150 nm in Zip13-KO mice dermis. We also found that the TGF-β1 level was significantly higher in Zip13-KO mice serum. These results suggest that collagen synthesis and collagen fibril fusion might be impaired in Zip13-KO mice and that the possible decrease of decorin level by reduction of the DS ratio probably caused an increase of free TGF-β1 in Zip13-KO mice. In conclusion, skin fragility due to defective ZIP13 protein may be attributable to impaired extracellular matrix synthesis accompanied by abnormal peripheral TGF-β homeostasis.

Bioavailability and bioavailable forms of collagen after oral administration to rats

The bioavailability and bioavailable forms of collagen after oral administration to rats were investigated in this study. The relative and absolute bioavailability of collagen were 57.8% and 49.6%, respectively, which was indirectly evaluated by the bioavailability of Hyp in collagen using a pharmacokinetic method. The amino acid profile of plasma showed that more than 63.4% of the collagen was absorbed from the intestine in the form of peptide, and there was a good linear correlation between the absorbed amount of an amino acid and its content in collagen (R(2) = 0.9225). The collagen peptides in plasma were purified by Sephadex G10 and Eclipse XDB C18 chromatography and further indentified (Ala-Asn, Ala-Hyp-Gly, Asp-Glu, Glu-Asn, Glu-Asp, Glu-Met, Gly-Pro-Hyp, Leu-Hyp, Leu-Met, Phe-Gly-Asn, Pro-Gly-Leu, Pro-Leu, Ser-Gly-Met, Ser-Hyp, Ser-Pro-Gly, Tyr-Met) with UPLC-ESI-MS. These results may help to speculate about the molecular mechanism behind the physiological effects of collagen after oral administration.

Apigenin induces dermal collagen synthesis via smad2/3 signaling pathway

Decrease in fibroblast-produced collagen has been proven to be the pivotal cause of skin aging, but there is no satisfactory drug which directly increases dermal thickness and collage density. Here we found that a flavonoid natural product, apigenin, could significantly increase collagen synthesis. NIH/3T3 and primary human dermal fibroblasts (HDFs) were incubated with various concentrations of apigenin, with dimethyl sulfoxide (DMSO) serving as the negative control. Real-time reverse-transcription polymerase chain reaction (PCR), Western Blot, and Toluidine blue staining demonstrated that apigenin stimulated type-I and type-III collagen synthesis of fibroblasts on the mRNA and protein levels. Meanwhile, apigenin did not induce expression of alpha smooth muscle actin (α-SMA) in vitro and in vivo, a fibrotic marker in living tissues. Then the production of collagen was confirmed by Masson’s trichrome stain, Picrosirius red stain and immunohistochemistry in mouse models. We also clarified that this compound induced collagen synthesis by activating smad2/3 signaling pathway. Taken together, without obvious influence on fibroblasts’ apoptosis and viability, apigenin could promote the type-I and type-III collagen synthesis of dermal fibroblasts in vitro and in vivo, thus suggesting that apigenin may serve as a potential agent for esthetic and reconstructive skin rejuvenation.

Detection of endogenous and food-derived collagen dipeptide prolylhydroxyproline (Pro-Hyp) in allergic contact dermatitis-affected mouse ear

Generation of collagen dipeptides and deposition of orally administered prolylhydroxyproline (Pro-Hyp) in local inflammatory sites were examined in mice with hapten (2,4-dinitrofluorobenzene)-induced dermatitis in the ear. Pro-Hyp content in the hapten-treated ear was significantly higher in the chronic phase of contact dermatitis than the vehicle control. In contrast, hydroxyprolylglycine contents remained at lower levels in all cases compared to Pro-Hyp. Four hours after the ingestion of [(13)C5,(15)N]Pro and [(13)C5,(15)N]Pro-Hyp, labeled-Pro-Hyp and Pro, respectively, appeared only in the ear with dermatitis. Thus, Pro-Hyp is generated and degraded as part of the rapid synthesis and degradation of collagen in the ear with dermatitis. In addition to the endogenously generated Pro-Hyp, the orally administered Pro-Hyp was deposited in the ears.