A modern baseline for the paired isotopic analysis of skin and bone in terrestrial mammals

We present the isotopic discrimination between paired skin and bone collagen from animals of known life history, providing a modern baseline for the interpretation of archaeological isotopic data. At present, the interpretation of inter-tissue variation (Δ (skin–bone) ) in mummified remains is based on comparisons with other archaeological material, which have attributed divergence to their contrasting turnover rates, with rapidly remodelling skin collagen incorporating alterations in environmental, cultural and physiological conditions in the months prior to death. While plausible, the lack of baseline data from individuals with known life histories has hindered evaluation of the explanations presented. Our analysis of a range of animals raised under a variety of management practices showed a population-wide trend for skin collagen to be depleted in 13 C by –0.7‰ and enriched in 15 N by +1.0‰ relative to bone collagen, even in stillborn animals. These results are intriguing and difficult to explain using current knowledge; however, on the basis of the findings reported here, we caution any results which interpret simply on differing turnover rates. We hypothesize that there may be a consistent difference in the routing of dietary protein and lipids between skin and bone, with potentially on-site synthesis of non-essential amino acids using carbon and nitrogen that have been sourced via different biochemical pathways.

FUNCTIONAL PROPERTIES OF CATFISH SKIN COLLAGEN HYDROLYSATES

Collagen hydrolysates were obtained from catfish skin collagen hydrolysis using catfish collagenase, pepsin and trypsin individually and mixed for 15-300min. The degree of hydrolysis , antioxidant activity based on, DPPH radical-scavenging activity (RSA), and reducing power (RP) for all obtained hydro lysates were studied , then the collagenase hydrolysate was (CH) was selected to be evaluated for antibacterial activity , functional properties including solubility, emulsification and foaming properties besides the toxicity . The highest values for RSA (72.5%) has been noticed when DH reached (24.30%) after 30 min. of hydrolysis by collagenase (CH). The water and oil holding capacities for this hydro lysate was compared to that for ASC (acid soluble collagen and PSC (pepsin soluble collagen), the results showed that the values recorded by CH were significantly higher than ASC & PSC. The molecular weight of CH peptides ranged from 180 to 11 Da. as analyzed by SDS- PAGE. The toxicity assay result revealed that CH is safe for human consumption. There was no antibacterial function for CH toward E.coli and S. aureus. At concentration of 2mg/ml. This study suggests that catfish collagen hydro lysate could be a good natural alternative for synthetic antioxidants in food industries.

Effect Collagen Concentration Tilapia Scales on the Quality of Burn Ointment

Collagen is one of the main connective tissue animal proteins and has been widely used as a biomedical material. Collagen is divided into XIX types. Type I collagen, among others, is obtained from bone, scales and skin. Collagen derived from type I can repair tissue or accelerate tissue regeneration to heal burns. The purpose of this research was to determine the addition of fish scale collagen extract to the characteristics of the burn ointment preparation in accordance with the Indonesian National Standard (SNI) and the best quality. The method used in this research is an experimental method of Completely Randomized Design (CRD) consisting of 4 collagen addition treatments: 0%, 2%, 4% and 6% repeated 5 times. Parameters in this method include physical-chemical parameters (pH, spreadability, shelf life and homogeneity) and organoleptic parameters (appearance, aroma, texture and color). Bayes test results, the concentration of the addition of tilapia scale collagen in the ointment preparation of 4% resulted in a value close to the control treatment. The addition of 4% collagen was the best treatment compared to 2% and 6% with a pH value of 6.12, dispersion of 3.22 cm, safe ointment preparation did not change at all during 28 days of storage. Based on the results of the organoleptic test parameters, the ointment at this concentration had a homogeneous appearance, slightly yellowish white color, a distinctive smell of collagen and a semi-solid texture, this was in accordance with the quality standard of the ointment and had the best quality characteristics.

Effect of the Addition Tilapia Skin Collagen Concentration to Lotion Characteristics

The purpose of this research was to determine the best concentration of the tilapia skin collagen addition to obtain the characteristics of the lotion in accordance with the established standards. The research was carried out at the Fishery Product Processing Technology Laboratory, Faculty of Fisheries and Marine Sciences, Padjadjaran University, Central Laboratory of Padjadjaran University and Faculty of Mathematics and Natural Sciences Laboratory of Padjadjaran University between March 2021 - June 2021. The method used in this research was experimental with a completely randomized design consisted of 5 treatments with 4 replications added the concentration of the tilapia skin collagen (0%, 4%, 5%, 6% and 7%) based on lotion formulations. Parameters observed included pH, viscosity, spreadability, weight loss, homogeneity and the organoleptic (appearance, color, scent, texture). The conclusion from this research was that the addition of 7% the tilapia skin collagen concentration was the best treatment with a homogeneous appearance, a slightly yellowish white color, a slightly lavender scent and a slightly thick texture. The lotion had pH value of 6.35, viscosity of 7,197 cP, 5.74 cm spreadability and a weight loss of 2.8%.

Physicochemical properties of graft copolymers of collagen and fibroin with polyacrylic acid

Certain physicochemical properties of the synthesized graft copolymers of raw skin collagen and natural silk fibroin with polyacrylic acid have been determined. The dependence of the solubility, density, and thermal properties of copolymers on the ratio of components and synthesis conditions has been established.

Valsartan and Sacubitril Combination Treatment Enhances Collagen Production in Older Adult Human Skin Cells

Collagen is a major component of the skin’s support system, allowing for firmness, elasticity, and mechanical strength. In older adults, skin collagen production decreases significantly, and is associated with increased sagging, wrinkling, and thinning. The Renin Angiotensin System (RAS) is a key hormonal system that changes with age and affects multiple organ systems. While primary health benefits of Angiotensin (Ang) receptor type1 (AT1 R) blockers (ARBs) are believed to arise from systemic effects on blood pressure. There exists a skin-specific Renin Angiotensin System (RAS), but the impact of ARBs on older skin is unknown. Human skin fibroblasts from individuals aged 2 (young individual) and 57 (older individual) were treated with drugs that alter RAS: Valsartan (an ARB) and neprilysin inhibitor Sacubitril. Fibroblast proliferation and collagen production was quantified in response to the drug treatment using fluorescence microscopy. Fibroblasts from 57-year-old individuals were slower to proliferate and had less collagen content as compared to fibroblasts from young individual. Valsartan alone treatment had no effect on collagen production from young or old fibroblasts. In contrast, Sacubitril treatment increased collagen production by approximately three-fold in young (2.87 ± 0.27 RFU, P<.0001), and older (2.93 ± 0.53 RFU, P<.0001) fibroblasts. Concomitant treatment with Valsartan and Sacubitril increased collagen production by five-fold increase (5.36 ± 1.08 RFU, P<.0001) in young fibroblasts, and four-fold (4.18 ± 0.96 RFU, P=.003) in older cells. This study demonstrates a novel use for the widely prescribed drug combination, Sacubitril and Valsartan, which significantly improves collagen production in older adult fibroblasts.

ACE Inhibitory Peptide from Skin Collagen Hydrolysate of Takifugu bimaculatus as Potential for Protecting HUVECs Injury

Angiotensin-I-converting enzyme (ACE) is a crucial enzyme or receptor that catalyzes the generation of potent vasopressor angiotensin II (Ang II). ACE inhibitory peptides from fish showed effective ACE inhibitory activity. In this study, we reported an ACE inhibitory peptide from Takifugu bimaculatus (T. bimaculatus), which was obtained by molecular docking with acid-soluble collagen (ASC) hydrolysate of T. bimaculatus. The antihypertensive effects and potential mechanism were conducted using Ang-II-induced human umbilical vein endothelial cells (HUVECs) as a model. The results showed that FNLRMQ alleviated the viability and facilitated apoptosis of Ang-II-induced HUVECs. Further research suggested that FNLRMQ may protect Ang-II-induced endothelial injury by regulating Nrf2/HO-1 and PI3K/Akt/eNOS signaling pathways. This study, herein, reveals that collagen peptide FNLRMQ could be used as a potential candidate compound for antihypertensive treatment, and could provide scientific evidence for the high-value utilization of marine resources including T. bimaculatus.

The Bioactivity Prediction of Peptides from Tuna Skin Collagen Using Integrated Method Combining In Vitro and In Silico

The hydrolysates and peptide fractions of bigeye tuna (Thunnus obesus) skin collagen have been successfully studied. The hydrolysates (HPA, HPN, HPS, HBA, HBN, HBS) were the result of the hydrolysis of collagen using alcalase, neutrase, and savinase. The peptide fractions (PPA, PPN, PPS, PBA, PBN, PBS) were the fractions obtained following ultrafiltration of the hydrolysates. The antioxidant activities of the hydrolysates and peptide fractions were studied using the DPPH method. The effects of collagen types, enzymes, and molecular sizes on the antioxidant activities were analyzed using profile plots analysis. The amino acid sequences of the peptides in the fraction with the highest antioxidant activity were analyzed using LC-MS/MS. Finally, their bioactivity and characteristics were studied using in silico analysis. The hydrolysates and peptide fractions provided antioxidant activity (6.17–135.40 µmol AAE/g protein). The lower molecular weight fraction had higher antioxidant activity. Collagen from pepsin treatment produced higher activity than that of bromelain treatment. The fraction from collagen hydrolysates by savinase treatment had the highest activity compared to neutrase and alcalase treatments. The peptides in the PBN and PPS fractions of <3 kDa had antidiabetic, antihypertensive and antioxidant activities. In conclusion, they have the potential to be used in food and health applications.