A double-blind, placebo-controlled, randomised, clinical study on the effectiveness of collagen peptide on osteoarthritis

An investigation of water status in gelatin methacrylate hydrogels by means of water relaxometry and differential scanning calorimetry

The relationship between molecular structure and water dynamics is a fundamental yet often neglected subject in the field of hydrogels for drug delivery, bioprinting, as well as biomaterial science and tissue engineering & regenerative medicine (TE&RM). Water is a fundamental constituent of hydrogel systems and engages via hydrogen bonding with the macromolecular network. The methods and techniques to measure and reveal the phenomena and dynamics of water within hydrogels are still limited. In this work, differential scanning calorimetry (DSC) was used as a quantitative method to analyze freezable (including free and freezable bound) and non-freezable bound water within gelatin methacrylate (GelMA) hydrogels. Nuclear magnetic resonance (NMR) is a complementary method for the study of water behavior and can be used to measure the spin-relaxation of water hydrogen nuclei, which is related to water dynamics. In this research, nuclear magnetic resonance relaxometry was employed to investigate the molecular state of water in GelMA hydrogels using spin-lattice (T1) and spin-spin (T2) spin-relaxation time constants. The data displays a trend of increasing bound water content with increasing GelMA concentration. In addition, T2 values were further applied to calculate microviscosity and translational diffusion coefficients. Water relaxation under various chemical environments, including different media, temperatures, gelatin sources, as well as crosslinking effects, were also examined. These comprehensive physical data sets offer fundamental insight into biomolecule transport within the GelMA hydrogel system, which ultimately are important for drug delivery, bioprinting, as well as biomaterial science and TE&RM communities.

Efficacy and safety of collagen derivatives for osteoarthritis: A trial sequential meta-analysis

OBJECTIVE

To investigate the efficacy and safety of collagen derivatives for osteoarthritis.

DESIGN

PubMed, Embase, and Cochrane Library were searched till June 2023 for randomized controlled trials (RCTs) investigating collagen derivatives for treating osteoarthritis. Data were independently extracted by two authors. The risk of bias was assessed using the RoB 2 tool. A random-effects meta-analysis was performed within a frequentist framework. The certainty of evidence was evaluated using the Grading of Recommendations, Assessment, Development, and Evaluations approach.

RESULTS

A total of 35 RCTs involving 3165 patients were included. The main analysis of the primary outcome was based on 25 RCTs involving 2856 patients. Collagen derivatives exerted small-to-moderate effects on pain alleviation (standardized mean difference [SMD] -0.35, 95% confidence interval [CI] -0.48 to -0.22, moderate certainty) and function improvement (SMD -0.31, 95%CI -0.41 to -0.22, high certainty) compared with the control. Collagen derivatives were safe; they did not increase the risk of withdrawal or adverse events compared with the control. The trial sequential analyses indicated that this study had sufficient statistical power for deriving definitive conclusions, confirming the robustness of our findings.

CONCLUSIONS

Strong evidence supports the efficacy and safety of collagen derivatives for osteoarthritis treatment.

EMID2 is a novel biotherapeutic for aggressive cancers identified by in vivo screening

BACKGROUND

New drugs to tackle the next pathway or mutation fueling cancer are constantly proposed, but 97% of them are doomed to fail in clinical trials, largely because they are identified by cellular or in silico screens that cannot predict their in vivo effect.

METHODS

We screened an Adeno-Associated Vector secretome library (> 1000 clones) directly in vivo in a mouse model of cancer and validated the therapeutic effect of the first hit, EMID2, in both orthotopic and genetic models of lung and pancreatic cancer.

RESULTS

EMID2 overexpression inhibited both tumor growth and metastatic dissemination, consistent with prolonged survival of patients with high levels of EMID2 expression in the most aggressive human cancers. Mechanistically, EMID2 inhibited TGFβ maturation and activation of cancer-associated fibroblasts, resulting in more elastic ECM and reduced levels of YAP in the nuclei of cancer cells.

CONCLUSION

This is the first in vivo screening, precisely designed to identify proteins able to interfere with cancer cell invasiveness. EMID2 was selected as the most potent protein, in line with the emerging relevance of the tumor extracellular matrix in controlling cancer cell invasiveness and dissemination, which kills most of cancer patients.

Analgesic efficacy of collagen peptide in knee osteoarthritis: a meta-analysis of randomized controlled trials

BACKGROUND

The management of knee osteoarthritis involves various treatment strategies. It is important to explore alternative therapies that are both safe and effective. Collagen peptides have emerged as a potential intervention for knee osteoarthritis. This study aims to evaluate the analgesic effects and safety of collagen peptide in patients diagnosed with knee osteoarthritis.

METHODS

We conducted a systematic literature search following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Multiple databases including PubMed, Scopus, EMBASE, Web of Science, Cochrane, and ClinicalTrials.gov were searched for randomized controlled trials (RCTs) published up to 27 May 2023 that focused on the analgesic outcomes and adverse events associated with collagen peptides or hydrolyzed collagen in patients with osteoarthritis. We assessed the quality of the included studies and the strength of evidence using the Cochrane ROB 2.0 tool and Grading of Recommendations, Assessment, Development, and Evaluations.

RESULTS

Four trials involving 507 patients with knee osteoarthritis were included and analyzed using the random-effects model. All these trials were considered to have a high risk of bias. Our results revealed a significant difference in pain relief between the collagen peptide group and the placebo group in patients with knee osteoarthritis (standardized mean difference: - 0.58; 95% CI - 0.98, - 0.18, p = 0.004; I2: 68%; quality of evidence: moderate). However, there was no significant difference in the risk of adverse events between collagen peptide and placebo (odds ratio: 1.66; 95% CI 0.99, 2.78, p = 0.05; I2: 0%; quality of evidence: very low).

CONCLUSIONS

Our findings demonstrate significant pain relief in patients with knee osteoarthritis who received collagen peptides compared to those who received placebo. In addition, the risk of adverse events did not differ significantly between the collagen peptide group and the placebo group. However, due to potential biases and limitations, well-designed randomized controlled trials are needed to validate and confirm these findings.

Collagen Hydrolysates: A Source of Bioactive Peptides Derived from Food Sources for the Treatment of Osteoarthritis

Osteoarthritis (OA) is the most common joint disorder, with a social and financial burden that is expected to increase in the coming years. Currently, there are no effective medications to treat it. Due to limited treatment options, patients often resort to supplements, such as collagen hydrolysates (CHs). CHs are products with low molecular weight (MW) peptides, often between 3 and 6 kDa, and are a result of industrialized processed collagen. Collagen extraction is often a by-product of the meat industry, with the main source for collagen-based products being bovine, although it can also be obtained from porcine and piscine sources. CHs have demonstrated positive results in clinical trials related to joint health, such as decreased joint pain, increased mobility, and structural joint improvements. The bioactivity of CHs is primarily attributed to their bioactive peptide (BAP) content. However, there are significant knowledge gaps regarding the digestion, bioavailability, and bioactivity of CH-derived BAPs, and how different CH products compare in that regard. The present review discusses CHs and their BAP content as potential treatments for OA.

Ingestion of a collagen peptide containing high concentrations of prolyl-hydroxyproline and hydroxyprolyl-glycine reduces advanced glycation end products levels in the skin and subcutaneous blood vessel walls: a randomized, double-blind, placebo-controlled study

In this randomized, double-blind, placebo-controlled study, we investigated the effects of collagen peptides (CP) containing high concentrations of prolyl-hydroxyproline and hydroxyprolyl-glycine on advanced glycation end products (AGEs) levels in the skin and subcutaneous blood vessel walls. A total of 31 individuals aged 47-87 years were randomly assigned to receive either 5 g/day of fish-derived CP or a placebo for 12 weeks. Body and blood compositions and AGEs levels were measured at the beginning and end of the study. No adverse events were observed, and both groups' blood and body compositions did not change significantly. However, the CP group had significantly lower AGEs levels and a slightly lower insulin resistance index (homeostasis model assessment ratio [HOMA-R]) than the placebo group. In addition, the percentage changes in AGEs and HOMA-R levels were positively and strongly correlated in both groups. These findings suggest that fish-derived CP may be effective in reducing AGEs levels and improving insulin resistance.

Effects of collagen peptide supplementation on cardiovascular markers: a systematic review and meta-analysis of randomised, placebo-controlled trials

Previous studies have advocated that collagen peptide supplementation (CPS) can positively affect cardiovascular health. However, the widespread impact of CPS on CVD-related markers is not fully resolved. Consequently, the current systematic review and meta-analysis aimed to assess the efficacy of CPS on CVD-related markers. A systematic search in the Scopus, PubMed and ISI Web of Science databases were completed to identify relevant randomised, placebo-controlled trials (RCT) published up to November 2021. Mean Differences were pooled using a random-effects model, while publication bias, sensitivity analyses and heterogeneity were assessed using previously validated methods. Twelve RCT, comprising of a total of eleven measured markers, were selected for the quantitative analysis. Pooled data revealed that CPS significantly decreased fat mass (-1·21 kg; 95 % CI: -2·13, -0·29; I² = 0·0 %; P = 0·010) and increased fat-free mass, based on body mass percentage (1·49 %; 95 % CI: 0·57, 2·42; I² = 0·0 %; P = 0·002). Moreover, collagen peptide supplementation led to a significant decrease in serum LDL (-4·09 mg/dl; 95 % CI: -8·13, -0·04; I² = 93·4 %; P = 0·048) and systolic blood pressure (SBP) (-5·04 mmHg; 95 % CI: -9·22, -0·85; I² = 98·9 %; P = 0·018). Our analysis also indicated that CPS did not affect glycemic markers. Our outcomes indicate that CPS reduces fat mass, LDL and SBP while increasing fat-free mass. Future investigations with longer CPS duration are needed to expand on our results.

Collagen Supplementation for Joint Health: The Link between Composition and Scientific Knowledge

Osteoarthritis (OA) is the most common joint disease, generating pain, disability, and socioeconomic costs worldwide. Currently there are no approved disease-modifying drugs for OA, and safety concerns have been identified with the chronic use of symptomatic drugs. In this context, nutritional supplements and nutraceuticals have emerged as potential alternatives. Among them, collagen is being a focus of particular interest, but under the same term different types of collagens coexist with different structures, compositions, and origins, leading to different properties and potential effects. The aim of this narrative review is to generally describe the main types of collagens currently available in marketplace, focusing on those related to joint health, describing their mechanism of action, preclinical, and clinical evidence. Native and hydrolyzed collagen are the most studied collagen types for joint health. Native collagen has a specific immune-mediated mechanism that requires the recognition of its epitopes to inhibit inflammation and tissue catabolism at articular level. Hydrolyzed collagen may contain biologically active peptides that are able to reach joint tissues and exert chondroprotective effects. Although there are preclinical and clinical studies showing the safety and efficacy of food ingredients containing both types of collagens, available research suggests a clear link between collagen chemical structure and mechanism of action.

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.

Reduced Visceral Fat Weight and Body Weight Due to Ingestion of Fermented Collagen Peptide in High-Fat Diet-Fed Obese Mice

Oral ingestion of collagen hydrolysate has various benecial effects. We developed a novel fermented collagen peptide (FCP), different from the conventional collagen peptides, by fermenting gelatin with Aspergillus sojae. This study aimed to investigate the effect of FCP in inhibiting fat accumulation under high-fat loading. Male C57BL/6J mice were fed a low- or high-fat diet, or a high-fat diet including 5% FCP for 28 d. Body weight, visceral fat weight, adiponectin levels, leptin concentration, fatty acid synthase (FAS) activity, and carnitine palmitoyltransferase 1A (CPT) activity were determined. FCP supplementation was found to significantly decrease the body weight, visceral fat weight, leptin concentration, and FAS activity, and increase adiponectin levels and CPT activity compared to that in the high-fat diet-fed group. In conclusion, FCP intake reduced visceral fat weight and body weight in high-fat diet-fed mice.

Hatched Eggshell Membrane Can Be a Novel Source of Antioxidant Hydrolysates to Protect against H2O2-Induced Oxidative Stress in Human Chondrocytes

Natural antioxidants derived from agricultural by-products have great promise and ecological advantages in the treatment of oxidative stress-related diseases. The eggshell membrane (ESM) from hatched eggs, i.e., the hatched ESM, is a globally abundant agricultural byproduct, and its high-value utilization has been rarely studied compared to the well-studied ESM from fresh eggs. In this research, we systematically characterized the hatched ESM as a novel source of antioxidant hydrolysates and explored their potential role in H2O2-induced human chondrocytes. The results showed that the hatched ESM is a protein-rich fibrous mesh material with a significantly different structure and composition from those of fresh ESM. Enzymatic hydrolysis of hatched ESM can produce antioxidant hydrolysates rich in low molecular weight (MW) peptides, which mainly derived from the Lysyl oxidase homolog by Nano-LC-MS/MS analysis. The peptide fraction with MW < 3 kDa (HEMH-I) exhibited the highest DPPH radical scavenging, Fe2+-chelating, and Fe3+-reducing abilities. In H2O2-induced human SW1353 chondrocytes, HEMH-I treatment significantly increased the cell viability and ameliorated oxidative stress, inflammatory response, and cartilage matrix degradation by reducing the level of ROS, matrix metalloprotease 3 (MMP3), MMP13, and IL-6, and by promoting the expression of SOD and type II collagen, potentially through activating the cellular Keap1/Nrf2/HO-1 pathway. This study provides a theoretical basis for the value-added application of hatched ESM waste to produce antioxidant hydrolysates and indicates their potential as functional food and pharmaceuticals.

A novel Atlantic salmon (Salmo salar) bone collagen peptide delays osteoarthritis development by inhibiting cartilage matrix degradation and anti-inflammatory

Nowadays, the biological activity of collagen peptides has been revealed, but the effect of Atlantic salmon (Salmo salar) bone-derived collagen peptide (CPs) on osteoarthritis remains unclear. In this study, CPs was identified as a small molecular weight peptide rich in Gly-X-Y structure. Meanwhile, interleukin-1β (IL-1β)-induced hypertrophic chondrocytes and partial medial meniscectomy (pMMx) surgery model in rats were performed. In IL-1β stimulated chondrocytes, CPs significantly increased the type-II collagen content, reduced the type-X collagen abundance and chondrocytes apoptosis. Meanwhile, CPs reversed the increased expression of matrix metalloproteinase, metalloproteinase with thrombospondin motifs and RUNX family transcription factor 2 in chondrocytes induced by IL-1β. In vivo, CPs increased pain tolerance of rats and without organ toxicity at 1.6 g/kg.bw. CPs significantly decreased the levels of COMP and Helix-II in serum. Furthermore, a significant decrease of IL-1β in synovial fluid and cartilage tissue were observed by CPs intervention. From Micro-CT, CPs (0.8 g/kg.bw) significantly decreased Tb.sp and SMI value. Meanwhile, the expression of tumor necrosis factor and interleukin-6 were reduced by CPs administration both in vitro and in vivo. Together, CPs showed potential to be a novel and safe dietary supplement for helping anti-inflammatory and cartilage regeneration, ultimately hindering osteoarthritis development. However, the clear mechanism of CPs's positive effect on osteoarthritis needs to be further explored.

Os efeitos do colágeno hidrolisado e do peptídeo de colágeno no tratamento de lesões condrais superficiais: Um estudo experimental

Objetivo Avaliar os efeitos do colágeno hidrolisado e do peptídeo de colágeno no tratamento de lesões condrais superficiais de ratos.

Método Foram utilizados 18 Rattus norvegicus nesta pesquisa. O dano articular foi induzido por uma única infiltração intra-articular de iodoacetato de sódio (solução 2 mg), injetada através do ligamento patelar da articulação dos animais previamente anestesiados. Os animais foram distribuídos em três grupos: grupo controle, grupo peptídeo de colágeno e grupo colágeno hidrolisado. O tratamento foi realizado por 30 dias com a administração via oral do peptídeo de colágeno ou do colágeno hidrolisado. Posteriormente, foi realizada a eutanásia dos experimentos e seguiu-se para o estudo das alterações condrais articulares. Os resultados foram avaliados conforme contagem de condrócitos por cluster e através da avaliação histológica segundo Pritzker et al.

Resultados Ao observar os estágios de lesão, não foi observada significância estatística entre os grupos controle, colágeno hidrolisado e peptídeo de colágeno (p = 0,11). Ao observar os escores, houve significância estatística na comparação do grupo tratado com colágeno hidrolisado e o grupo peptídeo colágeno (p < 0,05), porém sem diferença estatística em relação ao grupo controle.

Conclusão Os tratamentos propostos da lesão condral induzida com uso de colágeno hidrolisado ou peptídeos de colágeno via oral mostraram-se eficazes, com estabilização ou regressão da lesão apresentada em ratos, merecendo novas pesquisas experimentais com o intuito de compreender e melhorar o desfecho primário deste trabalho.

Collagen peptide promotes DSS-induced colitis by disturbing gut microbiota and regulation of macrophage polarization

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

Is collagen supplementation friend or foe in rheumatoid arthritis and osteoarthritis? A comprehensive systematic review

Rheumatoid arthritis (RA) and osteoarthritis (OA) both are chronic diseases affecting joints. Immune response against collagen in both diseases may have a role in the initiation and progression of the disease. There is a hypothesis that suppression of immune response vs collagen could be a therapeutic approach in RA and OA. Exposure of gut immune system to collagen is a way to suppress immune response against collagen in the joints. So, the current systematic review is aimed to evaluate the effects of collagen supplementation in OA and RA patients. In the current systematic review, online electronic databases including PubMed/MEDLINE, Web of Sciences and Scopus were searched and finally 19 articles were included. The enrolled articles evaluated the effects of collagen supplementation on treatment of OA (n = 9) and RA (n = 10). Intact (n = 4) and hydrolyzed (n = 5) collagen were used to treat OA. All of the studies on RA used intact and type II collagen in their intervention. The last trials on collagen supplementation in RA and OA patients were performed in 2011 and 2016, respectively. High adverse effects of collagen supplementation and its low efficiency compared to routine treatments were reported by several included studies. Also, risk of bias assessment showed that most of the studies had poor quality. Therefore, it is not possible to definitely decide on the beneficial or detrimental effects of collagen supplementation on OA and RA patients. Further studies are needed to reach a final decision.

A Review on the Molecular Mechanisms of Action of Natural Products in Preventing Bone Diseases

The drugs used for treating bone diseases (BDs), at present, elicit hazardous side effects that include certain types of cancers and strokes, hence the ongoing quest for the discovery of alternatives with little or no side effects. Natural products (NPs), mainly of plant origin, have shown compelling promise in the treatments of BDs, with little or no side effects. However, the paucity in knowledge of the mechanisms behind their activities on bone remodeling has remained a hindrance to NPs’ adoption. This review discusses the pathological development of some BDs, the NP-targeted components, and the actions exerted on bone remodeling signaling pathways (e.g., Receptor Activator of Nuclear Factor κ B-ligand (RANKL)/monocyte/macrophage colony-stimulating factor (M-CSF)/osteoprotegerin (OPG), mitogen-activated protein kinase (MAPK)s/c-Jun N-terminal kinase (JNK)/nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), Kelch-like ECH-associated protein 1 (Keap-1)/nuclear factor erythroid 2–related factor 2 (Nrf2)/Heme Oxygenase-1 (HO-1), Bone Morphogenetic Protein 2 (BMP2)-Wnt/β-catenin, PhosphatidylInositol 3-Kinase (PI3K)/protein kinase B (Akt)/Glycogen Synthase Kinase 3 Beta (GSK3β), and other signaling pathways). Although majority of the studies on the osteoprotective properties of NPs against BDs were conducted ex vivo and mostly on animals, the use of NPs for treating human BDs and the prospects for future development remain promising.

Effects of diet on the outcomes of rheumatic and musculoskeletal diseases (RMDs): systematic review and meta-analyses informing the 2021 EULAR recommendations for lifestyle improvements in people with RMDs

BACKGROUND

A EULAR taskforce was convened to develop recommendations for lifestyle behaviours in rheumatic and musculoskeletal diseases (RMDs). In this paper, the literature on the effect of diet on the progression of RMDs is reviewed.

METHODS

Systematic reviews and meta-analyses were performed of studies related to diet and disease outcomes in seven RMDs: osteoarthritis (OA), rheumatoid arthritis (RA), systemic lupus erythematosus, axial spondyloarthritis, psoriatic arthritis, systemic sclerosis and gout. In the first phase, existing relevant systematic reviews and meta-analyses, published from 2013 to 2018, were identified. In the second phase, the review was expanded to include published original studies on diet in RMDs, with no restriction on publication date. Systematic reviews or original studies were included if they assessed a dietary exposure in one of the above RMDs, and reported results regarding progression of disease (eg, pain, function, joint damage).

RESULTS

In total, 24 systematic reviews and 150 original articles were included. Many dietary exposures have been studied (n=83), although the majority of studies addressed people with OA and RA. Most dietary exposures were assessed by relatively few studies. Exposures that have been assessed by multiple, well conducted studies (eg, OA: vitamin D, chondroitin, glucosamine; RA: omega-3) were classified as moderate evidence of small effects on disease progression.

CONCLUSION

The current literature suggests that there is moderate evidence for a small benefit for certain dietary components. High-level evidence of clinically meaningful effect sizes from individual dietary exposures on outcomes in RMDs is missing.

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.

Comparison of gelatin and low-molecular weight gelatin hydrolysate ingestion on hydroxyproline (Hyp), Pro-Hyp and Hyp-Gly concentrations in human blood

This study showed that gelatin ingestion significantly increased prolyl-hydroxyproline (Pro-Hyp) levels in plasma of 9 subjects, with maximum concentrations of 15.5 ± 3.0 nmol/mL 2 h post-ingestion. Hydroxyprolyl-glycine (Hyp-Gly) concentrations were significantly increased and reached a maximal level of 2.3 ± 0.5 nmol/mL 1 h post-ingestion of gelatin. A low molecular weight gelatin hydrolysate (LMW-GH) significantly enhanced concentrations of both peptides, while gelatin hydrolysate ingestion did not significantly enhance the maximum concentration and area under the plasma concentration-time curve (AUC) of Hyp-Gly relative to gelatin. The absorption of free Hyp following gelatin ingestion (94.4 ± 16.4 nmol/mL) was significantly lower relative to GH (150.9 ± 15.3 nmol/mL) and LMW-GH (169.1 ± 32.5 nmol/mL). The present study is the first report demonstrating that Hyp-containing peptides are elevated to μM levels in human plasma after gelatin ingestion. These results suggested that gelatin is useful as a functional food as effectively as GH.

Stimulation of the Runx2 P1 promoter by collagen-derived dipeptide prolyl-hydroxyproline bound to Foxg1 and Foxo1 in osteoblasts

Collagen-derived dipeptide prolyl-hydroxyproline (Pro-Hyp) directly binds to the forkhead box g1 (Foxg1) protein and causes it to undergo structural alteration. Pro-Hyp also promotes the production of a regulator of osteoblast differentiation, Runt-related transcription factor 2 (Runx2), through Foxg1, inducing osteoblast differentiation. In addition, Pro-Hyp disrupts the interaction between Foxg1 and Runx2, and Foxg1 appears to interact with Runx2 in the absence of Pro-Hyp. To elucidate the mechanism of Pro-Hyp that promotes osteoblast differentiation, we investigated whether Pro-Hyp regulates the Runx2 P1 promoter together with Foxg1. The present study revealed that Pro-Hyp is taken up by osteoblastic cells via the solute carrier family 15 member (Slc15a) 4. In the presence of Pro-Hyp, Runx2 is translocated from the nucleus to the cytoplasm and Foxg1 is translocated from the cytoplasm to the nucleus. We also found that Pro-Hyp promoted the interaction between Forkhead box o1 (Foxo1) and Runx2 and the dissociation of Foxg1 from Runx2. Moreover, we identified the Pro-Hyp response element in the Runx2 distal P1 promoter at nt −375 to −316, including the Runx2 binding sites and Fox core sequence. In the presence of Pro-Hyp, Runx2 is dissociated from the Pro-Hyp response element in the Runx2 distal P1 promoter. Subsequently, Foxg1 and Foxo1 activated the Runx2 promoter by binding to the Pro-Hyp response element. In summary, we delineated the mechanism by which Pro-Hyp stimulates the bone-related Runx2 distal P1 promoter activity in osteoblastic cells through Foxg1, Foxo1, and Runx2.

Nutraceutical Approach to Chronic Osteoarthritis: From Molecular Research to Clinical Evidence

Osteoarthritis (OA) is a degenerative inflammatory condition of the joint cartilage that currently affects approximately 58 million adults in the world. It is characterized by pain, stiffness, and a reduced range of motion with regard to the arthritic joints. These symptoms can cause in the long term a greater risk of overweight/obesity, diabetes mellitus, and falls and fractures. Although the current guidelines for the treatment of OA suggest, as the gold standard for this condition, pharmacological treatment characterized by non-steroidal anti-inflammatory drugs (NSAID), opioids, and cyclooxygenase (COX)-2-specific drugs, a great interest has been applied to nutraceutical supplements, which include a heterogeneous class of molecules with great potential to reduce inflammation, oxidative stress, pain, and joint stiffness and improve cartilage formation. The purpose of this review is to describe the potential application of nutraceuticals in OA, highlighting its molecular mechanisms of actions and data of efficacy and safety (when available).

Subcutaneous toxicity of a dual ionically cross-linked atelocollagen and sodium hyaluronate gel: Rat in vivo study for biological safety evaluation of the injectable hydrogel

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Hydrogel wound dressings are commonly used to stop bleeding and enhance healing.

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Hyaluronic acid and collagen are beneficial for wound healing, however, each polymer has limitations.

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A dual hydrogel combining the benefits of both biopolymers can be more effective for the treatment of various wound types.

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A composite of collagen and sodium hyaluronate did not generate significant subacute toxicity or reactivity in vivo.

Hydrogels are commonly used in wound dressing, as they retain moisture, accelerate healing, and break down necrotic tissue. This process enhances patient comfort levels while simultaneously reducing pain caused by dead tissue. The purpose of this study was to investigate the in vivo toxicity of a dual hydrogel consisting of type I atelocollagen cross-linked with sodium hyaluronate hydrogel used for wound dressing.

Porcine type I atelocollagen was cross-linked with sodium hyaluronate to form the hydrogel. For subcutaneous implantation, 0.5 ml of dual hydrogel was injected into two different sites of twenty rats per group. High density polyethylene rods were implanted subcutaneously to serve as a control material. Hematological assessment, blood biochemistry, histopathological, and histological evaluations were scored and graded after 4 weeks. A bioreactivity rating was used for evaluation of subacute toxicity.

Differences observed in blood chemical analysis and hematological analysis between control and test groups were within normal variations and considered unrelated to the test article implantation. No significant implantation-related lesions were observed in any of the major organs of all test animals. The overall histopathological index of the test article implantation sites was evaluated as 0. The bioreactivity rating was evaluated as non-irritant after 4-week subcutaneous implantation.

Overall, these results indicate that the dual hydrogel of type I atelocollagen and sodium hyaluronate is biologically and chemically safe for clinical application as a wound dressing.

Gastrointestinal Digestion Model Assessment of Peptide Diversity and Microbial Fermentation Products of Collagen Hydrolysates

Osteoarthritis (OA), the most common form of arthritis, is associated with metabolic diseases and gut microbiome dysbiosis. OA patients often take supplements of collagen hydrolysates (CHs) with a high peptide content. Following digestion, some peptides escape absorption to induce prebiotic effects via their colonic fermentation to generate short-chain fatty acids (SCFAs), branched-chain fatty acids (BCFAs) and colonic gases (NH₄ and H₂S). The capacity of CHs to generate microbial metabolites is unknown. Proteomic analysis of two CHs (CH-GL and CH-OPT) demonstrated different native peptide profiles with increased peptide diversity after in vitro gastric and small intestinal digestion. Subsequent 24 h fermentation of the CH digests in a dynamic gastrointestinal (GI) digestion model containing human fecal matter showed that CH-OPT increased (p < 0.05) H₂S, SCFAs (propionic, butyric and valeric acids), BCFAs, and decreased NH₄ in the ascending colon reactor with no major changes seen with CH-GL. No major effects were observed in the transverse and descending vessels for either CH. These findings signify that CHs can induce prebiotic effects in the ascending colon that are CH dependent. More studies are needed to determine the physiological significance of CH-derived colonic metabolites, in view of emerging evidence connecting the gut to OA and metabolic diseases.

A Double-Blind, Randomized, Placebo-Controlled Trial to Evaluate the Efficacy of a Hydrolyzed Chicken Collagen Type II Supplement in Alleviating Joint Discomfort

Joint pain and disease affects more than one in four adults in the United States. We conducted a double-blind, randomized, placebo-controlled trial to investigate the efficacy of a hydrolyzed chicken collagen type II (HCII) supplement in reducing joint-related discomfort such as pain and stiffness, and in improving mobility. We enrolled adults aged 40–65 (65.5% were women) who had joint discomfort, but had no co-morbidities, and who were not taking pain medications. The participants were randomized to receive either the HCII supplement (n = 47) or a placebo (n = 43) for eight weeks. At the baseline, and at week 4 and week 8, we administered the Western Ontario and McMaster Universities Arthritis Index (WOMAC) survey with three additional wrist-related questions and the Visual Analog Scale for assessments of joint-related symptoms. In the WOMAC stiffness and physical activity domains and in the overall WOMAC score, the HCII group had a significant reduction in joint-related discomforts compared with the placebo group. For example, at week 4, the HCII group had a 36.9% reduction in the overall WOMAC score, compared with a 14.3% reduction in the placebo group (p = 0.027). This HCII product is effective in reducing joint pain and stiffness and in improving joint function among otherwise healthy adults.

Monitoring urinary collagen metabolite changes following collagen peptide ingestion and physical activity using ELISA with anti active collagen oligopeptide antibody

Active collagen oligopeptides (ACOP) are bioactive collagen-derived peptides detected by a recently-established ELISA. To facilitate studies of the function and metabolism of these products, this study aims to determine which of these peptides is recognized by a novel anti-ACOP antibody used in this ELISA. We then investigate the effect of collagen peptide (CP) ingestion and exercise on urinary ACOP concentrations in a cohort of university student athletes using colorimetric, LC–MS/MS, and ELISA. We observed that the antibody showed strong cross-reactivity to Pro-Hyp and Gly-Pro-Hyp and weak cross-reactivity to commercial CP. CP ingestion increased the urinary level of ACOP over time, which correlated highly with urinary levels of peptide forms of Hyp and Pro-Hyp. Physical activity significantly decreased the urinary ACOP level. This study demonstrates changes in urinary ACOP following oral CP intake and physical activity using ELISA with the novel anti-ACOP antibody. Thus, ACOP may be useful as a new biomarker for collagen metabolism.

Protease Hydrolysates Ameliorates Inflammation and Intestinal Flora Imbalance in DSS-Induced Colitis Mice

Wheat germ and fish skin usually has not been completely utilized and sometimes may be discarded, thus causing a lot of waste. Here, we aim at exploring the therapeutic anti-inflammatory effects of protease hydrolysates of wheat germ and fish skin on the ulcerative colitis (UC) mice. In the current study, wheat germ protein hydrolysates (WGPH) and fish skin gelatin hydrolysates (FSGH) treated mice had a longer colon than the DSS-induced mice. Moreover, protease hydrolysates reversed DSS-induced gut dysbiosis. Protease hydrolysates were likely to shift the balance of the intestinal flora on inflammation. In summary, these findings suggested that protease hydrolysates might serve as a latent therapy for UC treatment.

Marine Collagen Hydrolysates Promote Collagen Synthesis, Viability and Proliferation While Downregulating the Synthesis of Pro-Catabolic Markers in Human Articular Chondrocytes

Cartilage is a non-innervated and non-vascularized tissue. It is composed of one main cell type, the chondrocyte, which governs homeostasis within the cartilage tissue, but has low metabolic activity. Articular cartilage undergoes substantial stresses that lead to chondral defects, and inevitably osteoarthritis (OA) due to the low intrinsic repair capacity of cartilage. OA remains an incurable degenerative disease. In this context, several dietary supplements have shown promising results, notably in the relief of OA symptoms. In this study, we investigated the effects of collagen hydrolysates derived from fish skin (Promerim^®30 and Promerim^®60) and fish cartilage (Promerim^®40) on the phenotype and metabolism of human articular chondrocytes (HACs). First, we demonstrated the safety of Promerim^® hydrolysates on HACs cultured in monolayers. Then we showed that, Promerim^® hydrolysates can increase the HAC viability and proliferation, while decreasing HAC SA-β-galactosidase activity. To evaluate the effect of Promerim^® on a more relevant model of culture, HAC were cultured as organoids in the presence of Promerim^® hydrolysates with or without IL-1β to mimic an OA environment. In such conditions, Promerim^® hydrolysates led to a decrease in the transcript levels of some proteases that play a major role in the development of OA, such as Htra1 and metalloproteinase-1. Promerim^® hydrolysates downregulated HtrA1 protein expression. In contrast, the treatment of cartilage organoids with Promerim^® hydrolysates increased the neosynthesis of type I collagen (Promerim^®30, 40 and 60) and type II collagen isoforms (Promerim^®30 and 40), the latter being the major characteristic component of the cartilage extracellular matrix. Altogether, our results demonstrate that the use of Promerim^® hydrolysates hold promise as complementary dietary supplements in combination with the current classical treatments or as a preventive therapy to delay the occurrence of OA in humans.

Intra-Articular Injections in Knee Osteoarthritis: A Review of Literature

Knee osteoarthritis (OA) is a chronic, degenerative, and progressive disease of articular cartilage, producing discomfort and physical disability in older adults. Thirteen percent of elderly people complain of knee OA. Management options for knee OA could be divided into the following categories: conservative, pharmacological, procedural, and surgical. Joint replacement is the gold standard, reserved for severe grades of knee OA, due to its complications rate and increased risk of joint revision. A nonsurgical approach is the first choice in the adult population with cartilage damage and knee OA. Yearly, more than 10% of knee OA-affected patients undergo intra-articular injections of different drugs, especially within three months after OA diagnosis. Several molecules, such as corticosteroids injection, hyaluronic acid (HA), and platelet-rich plasma (PRP), are managed to reduce the symptoms of patients with knee OA. The aim of this review was to offer an overview of intra-articular injections used for the treatment of OA and report the conventional pharmacological products used.

Marine Collagen Hydrolysates Downregulate the Synthesis of Pro-Catabolic and Pro-Inflammatory Markers of Osteoarthritis and Favor Collagen Production and Metabolic Activity in Equine Articular Chondrocyte Organoids

Articular cartilage experiences mechanical constraints leading to chondral defects that inevitably evolve into osteoarthritis (OA), because cartilage has poor intrinsic repair capacity. Although OA is an incurable degenerative disease, several dietary supplements may help improve OA outcomes. In this study, we investigated the effects of Dielen^® hydrolyzed fish collagens from skin (Promerim^®30 and Promerim^®60) and cartilage (Promerim^®40) to analyze the phenotype and metabolism of equine articular chondrocytes (eACs) cultured as organoids. Here, our findings demonstrated the absence of cytotoxicity and the beneficial effect of Promerim^® hydrolysates on eAC metabolic activity under physioxia; further, Promerim^®30 also delayed eAC senescence. To assess the effect of Promerim^® in a cartilage-like tissue, eACs were cultured as organoids under hypoxia with or without BMP-2 and/or IL-1β. In some instances, alone or in the presence of IL-1β, Promerim^®30 and Promerim^®40 increased protein synthesis of collagen types I and II, while decreasing transcript levels of proteases involved in OA pathogenesis, namely Htra1, and the metalloproteinases Mmp1-3, Adamts5, and Cox2. Both Promerim^® hydrolysates also decreased Htra1 protein amounts, particularly in inflammatory conditions. The effect of Promerim^® was enhanced under inflammatory conditions, possibly due to a decrease in the synthesis of inflammation-associated molecules. Finally, Promerim^® favored in vitro repair in a scratch wound assay through an increase in cell proliferation or migration. Altogether, these data show that Promerim^®30 and 40 hold promise as dietary supplements to relieve OA symptoms in patients and to delay OA progression.

Nutraceutical supplements in management of pain and disability in osteoarthritis: a systematic review and meta-analysis of randomized clinical trials

This study designed to evaluate the effect of nutraceutical supplementation on pain intensity and physical function in patients with knee/hip OA. The MEDLINE, Web of Science, Cochrane Library, Scopus, EMBASE, Google Scholar, Science direct, and ProQuest in addition to SID, Magiran, and Iranmedex were searched up to March 2020. Records (n = 465) were screened via the PICOS criteria: participants were patients with hip or knee OA; intervention was different nutritional supplements; comparator was any comparator; the outcome was pain intensity (Visual analogue scale [VAS]) and physical function (Western Ontario and McMaster Universities Arthritis [WOMAC] index); study type was randomized controlled trials. The random effects model was used to pool the calculated effect sizes. The standardized mean difference (SMD) of the outcome changes was considered as the effect size. The random effects model was used to combine the effect sizes. Heterogeneity between studies was assessed by Cochran's (Q) and I2 statistics. A total of 42 RCTs were involved in the meta-analysis. Nutritional supplementation were found to improve total WOMAC index (SMD = - 0.23, 95% CI - 0.37 to - 0.08), WOMAC pain (SMD = - 0.36, 95% CI - 0.62 to - 0.10) and WOMAC stiffness (SMD = - 0.47, 95% CI - 0.71 to - 0.23) subscales and VAS (SMD = - 0.79, 95% CI - 1.05 to - 0.05). Results of subgroup analysis according to the supplementation duration showed that the pooled effect size in studies with < 10 months, 10-20 months and > 20 months supplementation duration were 0.05, 0.27, and 0.36, respectively for WOMAC total score, 0.14, 0.55 and 0.05, respectively for WOAMC pain subscale, 0.59, 0.47 and 0.41, respectively for WOMAC stiffness subscale, 0.05, 0.57 and 0.53, respectively for WOMAC physical function subscale and 0.65, 0.99 and 0.12, respectively for VAS pain. The result suggested that nutraceutical supplementation of patients with knee/hip OA may lead to an improvement in pain intensity and physical function.

Role of Collagen Derivatives in Osteoarthritis and Cartilage Repair: A Systematic Scoping Review With Evidence Mapping

Introduction

There is currently no disease-modifying drug for osteoarthritis (OA), and some safety concerns have been identified about the leading traditional drugs. Therefore, research efforts have focused on alternatives such as supplementation with collagen derivatives. The objective of this scoping review is to examine the extent, range, and nature of research, and to summarize and disseminate research findings on the effects of collagen derivatives in OA and cartilage repair. The purpose is to identify gaps in the current body of evidence in order to further help progress research in this setting.

Methods

The databases Medline, Scopus, CENTRAL, TOXLINE, and CDSR were comprehensively searched from inception to search date. After studies selection against eligibility criteria, following recommended methods, data were charted from the retrieved articles and these were subsequently synthesized. Numerical and graphical descriptive statistical methods were used to show trends in publications and geographical distribution of studies.

Results

The systematic literature search identified a total of 10,834 records. Forty-one published studies were ultimately included in the review, 16 of which were preclinical studies and 25 were clinical studies (including four systematic reviews/meta-analyses). Collagen hydrolysate (CH) and undenatured collagen (UC) were the two types of collagen derivatives studied, with a total of 28 individual studies on CH and nine on UC. More than a third of studies originated from Asia, and most of them have been published after 2008. Oral forms of collagen derivatives were mainly studied; three in vivo preclinical studies and three clinical trials investigated intra-articularly injected CH. In most of the clinical trials, treatment durations varied between 3 and 6 months, with the shortest being 1.4 months and the longest 11 months. All in vivo preclinical studies and clinical trials, regardless of their quality, concluded on beneficial effects of collagen derivatives in OA and cartilage repair, whether used as nutritional supplement or delivered intra-articularly, and whatever the manufacturers of the products, the doses and the outcomes considered in each study.

Conclusions

Although current evidence shows some potential for the use of CH and UC as an option for management of patients with OA, there is still room for progress in terms of laboratory and clinical research before any definitive conclusion can be made. Harmonization of outcomes in preclinical studies and longer randomized placebo-controlled trials in larger populations with the use of recommended and validated endpoints are warranted before collagen derivatives can be recommended by large scientific societies.

Electronic Supplementary Material

The online version of this article (10.1007/s40744-020-00240-5) contains supplementary material, which is available to authorized users.

Regulatory T Cells in Bioactive Peptides-Induced Oral Tolerance; a Two-Edged Sword Related to the Risk of Chronic Diseases: A Systematic Review

This systematic review assesses the literature regarding beneficial and potential detrimental effects of bioactive peptides (BPs), focusing on evidence of regulatory T cells (T-regs) mediated oral tolerance (OT), collagen hydrolysate (CH) supplementation in osteoarthritis (OA) and the association of T-regs with chronic disease. The systematic search was done for articles published from inception to April 2019 using the PubMed and Scopus databases. About 3081 papers were identified by three different search strategies and screened against inclusion criteria which resulted in the inclusion of 22 articles. From the included articles, 12 papers were related to treatment of different disease in vivo by oral administration of BPs, six articles evaluated the effects of CH supplementation, as a rich source of BPs, on OA pain-relief and four observational studies assessed the association of circulating T-regs and risk of cancer and cardiovascular disease (CVD). The evidence obtained from first search strategy, indicated that oral administration of BPs improve clinical manifestations of animal models of allergy, arthritis, atherosclerosis, ulcerative colitis and allograft rejection by T-regs expansion; while, observational studies showed that although higher levels of circulating T-regs reduced risk of CVD and allergy, but, increased risk of solid cancers.

Mildly Processed Natural Eggshell Membrane Alleviates Joint Pain Associated with Osteoarthritis of the Knee: A Randomized Double-Blind Placebo-Controlled Study

Poor joint health is a significant burden to society. Millions of people suffer from some form of joint-related disorder or disease, most often osteoarthritis (OA). It was hypothesized that chicken eggshell membrane (EM) is effective in the regeneration of cartilage and/or immunomodulation (oral tolerance), and as such relieves pain and stiffness in joints commonly affected in arthritis. We tested this hypothesis in a double-blind, placebo-controlled EM intervention study. Of 150 male and female volunteers, 40-75 years of age and diagnosed with knee OA, 75 were randomly assigned to the EM intervention group and 75 to the placebo group. During 12 weeks, subjects received a daily capsule containing either 300 mg of EM or a placebo. The main primary dependent variable consisted of self-reported pain ratings on a Numerical Rating Scale Pain (NRS-P) 6 weeks after study start. As secondary dependent variables served NRS-P scores collected after 12 weeks, and Knee injury and self-reported Osteoarthritis Outcome Scores (Knee injury and Osteoarthritis Outcome Scores [KOOS]). NRS-P scores decreased for both groups at approximately the same rate, but only EM relieved self-reported pain scores obtained with the KOOS questionnaire starting 1 week after initiation of treatment. This effect was significant for two of five KOOS category scores, that is, "Pain" and "Daily Life" functioning, aggregate pain, and functioning scores composed of complaint ratings for a wide variety of daily activities. These scores showed long-lasting improvement, and demonstrated that EM extract successfully reliefs knee OA pain and contributes to daily life functioning.

Effectiveness of collagen supplementation on pain scores in healthy individuals with self-reported knee pain: a randomized controlled trial

The purpose of this study was to examine the effects of 12 weeks collagen peptide (CP) supplementation on knee pain and function in individuals with self-reported knee pain. Healthy physically active individuals (n = 167; aged 63 [interquartile range = 56-68] years) with self-reported knee pain received 10 g/day of CP or placebo for 12 weeks. Knee pain and function were measured with the Visual Analog Scale (VAS), the Lysholm questionnaire, and the Knee injury and Osteoarthritis Outcome Score (KOOS). Furthermore, we assessed changes in inflammatory, cartilage, and bone (bio)markers. Measurements were conducted at baseline and after 12 weeks of supplementation. Baseline VAS did not differ between CP and placebo (4.7 [2.5-6.1] vs. 4.7 [2.8-6.2], p = 0.50), whereas a similar decrease in VAS was observed after supplementation (-1.6 ± 2.4 vs. -1.9 ± 2.6, p = 0.42). The KOOS and Lysholm scores increased after supplementation in both groups (p values < 0.001), whereas the increase in the KOOS and Lysholm scores did not differ between groups (p = 0.28 and p = 0.76, respectively). Furthermore, CP did not impact inflammatory, cartilage, and bone (bio)markers (p values > 0.05). A reduced knee pain and improved knee function were observed following supplementation, but changes were similar between groups. This suggests that CP supplementation over a 12-week period does not reduce knee pain in healthy, active, middle-aged to elderly individuals. Novelty CP supplementation over a 12-week period does not reduce knee pain in healthy, active, middle-aged to elderly individuals. CP supplementation over a 12-week period does not impact on inflammatory, cartilage, and bone (bio)markers in healthy, active, middle-aged to elderly individuals.

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.

Food-Derived Collagen Peptides, Prolyl-Hydroxyproline (Pro-Hyp), and Hydroxyprolyl-Glycine (Hyp-Gly) Enhance Growth of Primary Cultured Mouse Skin Fibroblast Using Fetal Bovine Serum Free from Hydroxyprolyl Peptide

Prolyl-hydroxyproline (Pro-Hyp) and hydroxyprolyl-glycine (Hyp-Gly) appear in human blood after ingestion of collagen hydrolysate and trigger growth of fibroblasts attached on collagen gel, which has been associated with beneficial effects upon ingestion of collagen hydrolysate, such as improvement of skin and joint conditions. In the present study, inconsistent results were obtained by using different lots of fetal bovine serum (FBS). Fibroblasts proliferated in collagen gel without adding Pro-Hyp and Hyp-Gly and did not respond to addition of Pro-Hyp and Hyp-Gly, which raises doubts about conclusions from prior research. Unexpectedly high levels of hydroxyprolyl peptides, including Pro-Hyp, however, were present in the FBS (approximately 100 µM), and also in other commercially available forms of FBS (70-80 µM). After removal of low molecular weight (LMW, < 6000 Da) compounds from the FBS by size exclusion chromatography, Pro-Hyp and Hyp-Gly again triggered growth of fibroblasts attached on collagen and increased the number of fibroblasts migrated from mouse skin. These results indicate the presence of bioactive hydroxyprolyl peptides in commercially available FBS, which can mask effects of Pro-Hyp and Hyp-Gly supplementation; our work confirms that Pro-Hyp and Hyp-Gly do play crucial roles in proliferation of fibroblasts.

Effects of Collagen Hydrolysates on Human Brain Structure and Cognitive Function: A Pilot Clinical Study

This study investigated the effects of collagen hydrolysates (CH) on language cognitive function and brain structure. In this open-label study, 5 g CH was administered once a day for 4 weeks to 30 healthy participants aged 49-63 years. The primary outcome measures were the brain healthcare quotients based on gray matter volume (GM-BHQ) and fractional anisotropy (FA-BHQ). The secondary outcome measures were changes in scores between week 0 and week 4 for word list memory (WLM) and standard verbal paired associate learning (S-PA) tests as well as changes in the physical, mental, and role/social component summary scores of the Short Form-36(SF-36) quality of life instrument. CH ingestion resulted in significant improvements in FA-BHQ (p = 0.0095), a measure of brain structure, as well in scores for the WLM (p = 0.0046) and S-PA (p = 0.0007) tests, which measure cognitive function. There were moderate correlations between the change in WLM score and the change in GM-BHQ (r = 0.4448; Spearman's rank correlation) and between the change in S-PA score and the change in FA-BHQ (r = 0.4645). Daily ingestion of CH changed brain structure and improved language cognitive function.

Human Enriched Serum Following Hydrolysed Collagen Absorption Modulates Bone Cell Activity: from Bedside to Bench and Vice Versa

Collagen proteins are crucial components of the bone matrix. Since collagen-derived products are widely used in the food and supplement industry, one may raise the question whether collagen-enriched diets can provide benefits for the skeleton. In this study, we designed an innovative approach to investigate this question taking into account the metabolites that are formed by the digestive tract and appear in the circulation after ingestion of hydrolysed collagen. Blood samples collected in clinical and pre-clinical trials following ingestion and absorption of hydrolysed collagen were processed and applied on bone-related primary cell cultures. This original ex vivo methodology revealed that hydrolysed collagen-enriched serum had a direct impact on the behaviour of cells from both human and mouse origin that was not observed with controls (bovine serum albumin or hydrolysed casein-enriched serum). These ex vivo findings were fully in line with in vivo results obtained from a mouse model of post-menopausal osteoporosis. A significant reduction of bone loss was observed in mice supplemented with hydrolysed collagen compared to a control protein. Both the modulation of osteoblast and osteoclast activity observed upon incubation with human or mouse serum ex vivo and the attenuation of bone loss in vivo, clearly indicates that the benefits of hydrolysed collagen for osteoporosis prevention go beyond the effect of a simple protein supplementation.

Effects of 12 Weeks of Hypertrophy Resistance Exercise Training Combined with Collagen Peptide Supplementation on the Skeletal Muscle Proteome in Recreationally Active Men

Evidence has shown that protein supplementation following resistance exercise training (RET) helps to further enhance muscle mass and strength. Studies have demonstrated that collagen peptides containing mostly non-essential amino acids increase fat-free mass (FFM) and strength in sarcopenic men. The aim of this study was to investigate whether collagen peptide supplementation in combination with RET influences the protein composition of skeletal muscle. Twenty-five young men (age: 24.2 ± 2.6 years, body mass (BM): 79.6 ± 5.6 kg, height: 185.0 ± 5.0 cm, fat mass (FM): 11.5% ± 3.4%) completed body composition and strength measurements and vastus lateralis biopsies were taken before and after a 12-week training intervention. In a double-blind, randomized design, subjects consumed either 15 g of specific collagen peptides (COL) or a non-caloric placebo (PLA) every day within 60 min after their training session. A full-body hypertrophy workout was completed three times per week and included four exercises using barbells. Muscle proteome analysis was performed by liquid chromatography tandem mass spectrometry (LC-MS/MS). BM and FFM increased significantly in COL compared with PLA, whereas no differences in FM were detected between the two groups. Both groups improved in strength levels, with a slightly higher increase in COL compared with PLA. In COL, 221 higher abundant proteins were identified. In contrast, only 44 proteins were of higher abundance in PLA. In contrast to PLA, the upregulated proteins in COL were mostly associated with the protein metabolism of the contractile fibers. In conclusion, the use of RET in combination with collagen peptide supplementation results in a more pronounced increase in BM, FFM, and muscle strength than RET alone. More proteins were upregulated in the COL intervention most of which were associated with contractile fibers.

Safety of Symptomatic Slow-Acting Drugs for Osteoarthritis: Outcomes of a Systematic Review and Meta-Analysis

BACKGROUND

Symptomatic slow-acting drugs for osteoarthritis (SYSADOAs) are an important drug class in the treatment armamentarium for osteoarthritis (OA).

OBJECTIVE

We aimed to re-assess the safety of various SYSADOAs in a comprehensive meta-analysis of randomized placebo-controlled trials, using, as much as possible, data from full safety reports.

METHODS

We performed a systematic review and random-effects meta-analyses of randomized, double-blind, placebo-controlled trials that assessed adverse events (AEs) with various SYSADOAs in patients with OA. The databases MEDLINE, Cochrane Central Register of Controlled Trials (Ovid CENTRAL) and Scopus were searched. The primary outcomes were overall severe and serious AEs, as well as AEs involving the following Medical Dictionary for Regulatory Activities (MedDRA) system organ classes (SOCs): gastrointestinal, cardiac, vascular, nervous system, skin and subcutaneous tissue, musculoskeletal and connective tissue, renal and urinary system.

RESULTS

Database searches initially identified 3815 records. After exclusions according to the selection criteria, 25 studies on various SYSADOAs were included in the qualitative synthesis, and 13 studies with adequate data were included in the meta-analyses. Next, from the studies previously excluded according to the protocol, 37 with mainly oral nonsteroidal anti-inflammatory drugs (NSAIDs) permitted as concomitant medication were included in a parallel qualitative synthesis, from which 18 studies on various SYSADOAs were included in parallel meta-analyses. This post hoc parallel inclusion was conducted because of the high number of studies allowing concomitant anti-OA medications. Indeed, primarily excluding studies with concomitant anti-OA medications was crucial for a meta-analysis on safety. The decision for parallel inclusion was made for the purpose of comparative analyses. Glucosamine sulfate (GS), chondroitin sulfate (CS) and avocado soybean unsaponifiables (ASU; Piascledine®) were not associated with increased odds for any type of AEs compared with placebo. Overall, with/without concomitant OA medication, diacerein was associated with significantly increased odds of total AEs (odds ratio [OR] 2.22; 95% confidence interval [CI] 1.58-3.13; I2 = 52.8%), gastrointestinal disorders (OR 2.85; 95% CI 2.02-4.04; I2 = 62.8%) and renal and urinary disorders (OR 3.42; 95% CI 2.36-4.96; I2 = 17.0%) compared with placebo. In studies that allowed concomitant OA medications, diacerein was associated with significantly more dermatological disorders (OR 2.47; 95% CI 1.42-4.31; I2 = 0%) and more dropouts due to AEs (OR 3.18; 95% CI 1.85-5.47; I2 = 13.4%) than was placebo. No significant increase in serious or severe AEs was found with diacerein versus placebo.

CONCLUSIONS

GS and CS can be considered safe treatments for patients with OA. All eligible studies on ASU included in our analysis used the proprietary product Piascledine® and allowed other anti-OA medications; thus, the safety of ASU must be confirmed in future studies without concomitant anti-OA medications. Given the safety concerns with diacerein, its usefulness in patients with OA should be assessed, taking into account individual patient characteristics.

Amount of Collagen in the Meat Contained in Japanese Daily Dishes and the Collagen Peptide Content in Human Blood after Ingestion of Cooked Fish Meat

Objectives of the present study were to evaluate amounts of collagen in Japanese daily dishes and contents of food-derived collagen peptides in human blood. The meat in one serving of most Japanese daily dishes contains 0.2-2.5 g of collagen, except for beef tendon, eel with skin, and skinned shark tail (7.6-13.3 g). After ingestion of cooked shark meat, nine collagen di- and tripeptides were detected in plasma and the area under the curve of most peptides, except for Hyp-Gly and Pro-Hyp-Gly, was ∼30% of that after ingestion of collagen hydrolysate containing an equivalent amount of collagen. Likewise, only ∼30% of the total collagen in the meat was liberated into solution by pepsin and pancreatin digestion. Thus, ingestion of collagen-rich meat increases the collagen peptides in blood, which depends on not only the collagen content in the meat but also the susceptibility of the collagen/gelatin to digestive endoproteinases.