Anti-Oxidative and Anti-Aging Activities of Porcine By-Product Collagen Hydrolysates Produced by Commercial Proteases: Effect of Hydrolysis and Ultrafiltration

Development of a versatile optical pH sensor array for discrimination of anti-aging face creams

The certification of cosmetic products has always been a prominent concern. Here, we have developed a pH sensor and applied it in the field of cosmetic safety. Initially, we designed two probes, CH with aggregation-induced emission (AIE) effect and the near-infrared fluorophore derivative CYTYR. By encapsulating them with DSPE-PEG2000-NH2, we obtained the CHCY-lipo nano-micelles with fluorescence resonance energy transfer (FRET) response. By combining them into a sensor array called pC, we achieved sensitive detection of a wide pH range, ranging from 4.69 to 9.25. To validate the performance of the pC sensor array, we employed a multi-channel mode and applied it to differentiate commercial anti-aging creams. Through linear discriminant analysis and 3D fingerprint analysis, the pC sensor array successfully distinguished anti-aging creams from different countries, providing a rapid and accurate method for cosmetic safety identification. The results of this study demonstrate the potential of the pC sensor array for quick authentication of cosmetic products, offering significant support and application prospects in safeguarding consumer health.

Local and Systemic Peptide Therapies for Soft Tissue Regeneration: A Narrative Review

Background: The musculoskeletal system, due to inherent structure and function, lends itself to contributing toward joint pain, whether from inflammatory disorders such as rheumatoid arthritis, degenerative diseases such as osteoarthritis, or trauma causing soft tissue injury. Administration of peptides for treatment of joint pain or inflammation is an emerging line of therapy that seeks to offer therapeutic benefits while remaining safe and relatively non-invasive. Purpose: The purpose of this study is to review the current literature on existing oral peptide agents, intra-articular peptide agents, and new developments in human trials to assess route of administration (RoA) for drug delivery in terms of soft tissue regeneration. Study Design: Narrative Review. Methods: A comprehensive literature search was conducted using the PubMed database. The search included medical subject headings (MeSH) terms related to peptide therapy, soft tissue regeneration, and RoA. Inclusion criteria comprised articles focusing on the mechanisms of action of peptides, clinical or biochemical outcomes, and review articles. Exclusion criteria included insufficient literature or studies not meeting the set evidence level. Conclusion: The review identified various peptides demonstrating efficacy in soft tissue repair. Oral and intra-articular peptides showed distinct advantages in soft tissue regeneration, with intra-articular routes providing localized effects and oral routes offering systemic benefits. However, both routes have limitations in bioavailability and absorption. Still in their infancy, further inquiries/research into the properties and efficacy of emerging peptides will be necessary before widespread use. As a viable alternative prior to surgical intervention, peptide treatments present as promising candidates for positive outcomes in soft tissue regeneration.

Biologically Active Sheep Colostrum for Topical Treatment and Skin Care

Colostrum is gaining popularity in cosmetic products. The present study compared the composition and selected biological properties of colostrum from Polish sheep (colostrum 1) and Swiss sheep (colostrum 2), particularly those that can affect healthy or diseased skin. The antioxidant activity of the colostrums was measured using ABTS and DPPH assays. The effect on the proliferation of human skin fibroblasts, neonatal epidermal keratinocytes, and human diabetic fibroblast (dHF) cells isolated from diabetic foot ulcers was also assayed in vitro by MTT and Presto Blue tests, respectively. The colostrum simulated dHF cell proliferation by up to 115.4%. The highest used concentration of colostrum 1 stimulated normal fibroblast proliferation by 191.2% (24 h) and 222.2% (48 h). Both colostrums inhibited epidermal keratinocyte viability. The influence of the colostrums on the expression of genes related to proliferation (Ki67) and immune response (IL-6, PTGS-2, TSG-6) in dHF cells were compared. Colostrum 1 increased the rate of wound closure (scar test). Analysis of total fat, protein and fatty acid content found the Polish colostrum to be a richer source of fat than the Swiss colostrum, which contained a larger amount of protein. Both colostrums exhibit properties that suggest they could be effective components in cosmetic or medicinal formulations for skin care, especially supporting its regeneration, rejuvenation, and wound healing.

Optimization of fractionation with membranes of antioxidant enzymatic hydrolysate of Californian red worm (Eisenia fetida) protein

Problem

Earthworm is a valuable source of biologically and pharmacologically active compounds, with applications in the treatment of various types of diseases; however, the main application they have been given is in the production of organic fertilizer. One of the alternatives for obtaining bioactive compounds is by means of enzymatic hydrolysis.

Aim

This study proposes the optimization of the fractionation of the antioxidant enzymatic hydrolysate from Californian red worm (Eisenia fetida) protein.

Methodology

For this purpose, the worms were separated and hydrolyzed using the enzyme Alcalase 2.4L for 4000s. The obtained hydrolysate was fractionated by means of a crossflow tangential ultrafiltration system, with a 3 kDa molecular weight cut-off ceramic membrane. A response surface design of the composite central factorial type was implemented to evaluate the effect of pH, transmembrane pressure, and flow factors on the response variables transmission, volume reduction factor (VRF) and permeate flow resistance. The transmissions focused on the antioxidant peptides, measured by three conventional methods such as TEAC, FRAP, ORAC, also known as TTEAC, TFRAP and TORAC, respectively. The evaluated resistances were the total resistance (Rtotal), fouling resistance (Rfouling), and gel resistance (Rgel).

Result

The results showed that the three factors evaluated affect all the response variables either in their linear or quadratic terms or by some interaction. For each response variable, a mathematical model was obtained, with statistical significance and a non-significant lack of adjustment. The models obtained were used for a multi-objective optimization process in which transfers were maximized, and resistances were minimized. The efficiency of the optimum ultrafiltration process was 25 %.

Conclusion

The neutral-alkaline pH is ideal for the ultrafiltration process of bioactive peptides, as it is where the highest transmissions of peptides with antioxidative capacity are found. Under optimal conditions, the 3 kDa membrane permeate was found to exhibit higher antioxidant capacity than the retentate and feed. Based on this, the fraction of less than 3 kDa emerges as a potential multifunctional ingredient, thanks to its antioxidant properties.

A comparative study on inhibition of lung cancer cells by nanoemulsion, nanoliposome, nanogold and their folic acid conjugates prepared with collagen peptides from Taiwan tilapia skin

Valorization of fish processing waste to obtain value-added products such as collagen and bioactive peptides is a vital strategy to increase the economic value, reduce disposal problems, and prevent harmful impacts on both environment and health. This study aims to isolate two collagen peptides from Taiwan Tilapia skin and prepare 12 nanopeptides including nanoemulsion (NE), nanoliposome (NL), and nanogold (NG) without and with folic acid/chitosan (FA/CH) or FA ligand conjugation for comparison of their inhibition efficiency towards lung cancer cells A549 and normal lung cells MRC5. Acid-soluble collagen (yield, 21.58 %) was extracted using 0.5 M acetic acid and hydrolyzed to obtain two tilapia skin collagen peptides TSCP1 (482 Da) and TSCP2 (172 Da) respectively using 2.5 % and 12.5 % alcalase, with sample-to-water ratio at 1:30 (w/v), pH 8, temperature 50 °C, and hydrolysis time 6 h. Characterization of collagen peptides revealed the presence of type 1 collagen with a high amount of amino acids including glycine (32.6-33.1 %), alanine (13.6-14.0 %), proline (10.0-10.5 %), and hydroxyproline (7.3-7.6 %). TSCP1, TSCP2, and 12 nanopeptides showed a higher cytotoxicity towards A549 cells than MRC5 cells, with TSCP2 and its 6 nanopeptides exhibiting a lower IC50 compared to TSCP1 and its 6 nanopeptides. The mean particle size was 15.7, 33.6, and 16.0 nm respectively for TSCP2-NE, TSCP2-NL, and TSCP2-NG, but changed to 14.4, 36.3, and 17.9 nm following ligand conjugation with a shift in zeta potential from negative to positive for TSCP2-NE-FA/CH and TSCP2-NL-FA/CH. All nanopeptides were more effective than peptides in inhibiting the growth of A549 cells, with the lowest IC50 value being shown for TSCP2-NL-FA/CH (5.32 μg/mL), followed by TSCP2-NE-FA/CH (8.3 μg/mL), TSCP2-NE (22.4 μg/mL), TSCP2-NL (82.7 μg/mL), TSCP2-NG-FA (159.8 μg/mL), TSCP2-NG (234.0 μg/mL) and TSCP2 (359.7 μg/mL). Cell proportions of sub-G1, S, and G2/M phases increased dose-dependently, with a possible cell cycle arrest at G2/M phase. The proportion of necrotic cells was the highest for TSCP2, TSCP2-NE, TSCP2-NE-FA/CH, and TSCP2-NL, while that of late apoptotic cells dominated for TSCP2-NL-FA/CH, TSCP2-NG, and TSCP2-NG-FA. Similarly, TSCP2 and its 6 nanopeptides showed a dose-dependent rise in caspase-3, caspase-8, and caspase-9 activities for execution of apoptosis, with the ligand-conjugated nanopeptides being the most efficient, followed by nanopeptides and peptides. The outcome of this study demonstrated an effective strategy for valorization of Taiwan tilapia skin to obtain collagen peptides and their nanopeptides possessing anticancer activity and form a basis for in vivo study in the future.

Synthesis and investigation of new indole-containing vinyl sulfide derivatives: In silico and in vitro studies for potential therapeutic applications

Indoles featuring organosulfur compounds serve as privileged structural scaffolds in various biologically active compounds. This study investigates the biological properties of five synthetic sulphenyl vinyl indoles (3 a-e) using both in silico and in vitro methods. Computational analyses employing Swiss ADME and Molinspiration software reveal the remarkable inhibitory activity of compound 3 d against proteases and kinases (scores of 0.18 and 0.06, respectively). Furthermore, it demonstrates the ability to modulate ionic and G protein-coupled receptors (scores: -0.06 and 0.31, respectively) and serves as a ligand for nuclear receptors (score 0.15). In vitro investigations highlight the compounds' efficacy in countering ABTS+ radical attacks and reducing lipid peroxidation levels. Particularly noteworthy is the superior efficacy of compounds 3 a, 3 b, and 3 e in DPPH (EC50 3 a: 268.5 μM) and TEAC assays (EC50 3 a: 49.9 μM; EC50 3 b: 133.4 μM, and EC50 3 e: 84.9 μM), as well as TBARS levels. Compound 3 c significantly reduces acetylcholinesterase activity, positioning itself as a noteworthy enzyme inhibitor. This study emphasizes the versatile biological potential of synthetic indole derivatives, suggesting their applicability for therapeutic purposes.

From microbes to molecules: a review of microbial-driven antioxidant peptide generation

Oxidative stress, arising from excess reactive oxygen species (ROS) or insufficient antioxidant defenses, can damage cellular components, such as lipids, proteins, and nucleic acids, resulting in cellular dysfunction. The relationship between oxidative stress and various health disorders has prompted investigations into potent antioxidants that counteract ROS's detrimental impacts. In this context, antioxidant peptides, composed of two to twenty amino acids, have emerged as a unique group of antioxidants and have found applications in food, nutraceuticals, and pharmaceuticals. Antioxidant peptides are sourced from natural ingredients, mainly proteins derived from foods like milk, eggs, meat, fish, and plants. These peptides can be freed from their precursor proteins through enzymatic hydrolysis, fermentation, or gastrointestinal digestion. Previously published studies focused on the origin and production methods of antioxidant peptides, describing their structure-activity relationship and the mechanisms of food-derived antioxidant peptides. Yet, the role of microorganisms hasn't been sufficiently explored, even though the production of antioxidant peptides frequently employs a variety of microorganisms, such as bacteria, fungi, and yeasts, which are recognized for producing specific proteases. This review aims to provide a comprehensive overview of microorganisms and their proteases participating in enzymatic hydrolysis and microbial fermentation to produce antioxidant peptides. This review also covers endogenous peptides originating from microorganisms. The information obtained from this review might guide the discovery of novel organisms adept at generating antioxidant peptides.

The Radical Scavenging Activities and Anti-Wrinkle Effects of Soymilk Fractions Fermented with Lacticaseibacillus paracasei MK1 and Their Derived Peptides

Soybean-derived peptides exert several beneficial effects in various experimental models. However, only a few studies have focused on the radical scavenging and anti-wrinkle effects of soymilk-derived peptides produced via different processes, such as fermentation, enzymatic treatment, and ultrafiltration. Therefore, in this study, we investigated the radical scavenging and antiwrinkle effects of soymilk fractions produced using these processes. We found that 50SFMKUF5, a 5 kDa ultrafiltration fraction fermented with Lacticaseibacillus paracasei MK1 after flavourzyme treatment, exhibited the highest radical scavenging activity using the 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay as well as potent anti-wrinkle effects assessed by type 1 procollagen production and tumor necrosis factor-α production in ultraviolet B (UVB)-treated human dermal fibroblasts and HaCaT keratinocytes. To identify potential bioactive peptides, candidate peptides were synthesized, and their anti-wrinkle effects were assessed. APEFLKEAFGVN (APE), palmitoyl-APE, and QIVTVEGGLSVISPK peptides were synthesized and used to treat UVB-irradiated fibroblasts, HaCaT keratinocytes, and α-melanocyte-stimulating hormone-induced B16F1 melanoma cells. Among these peptides, Pal-APE exerted the strongest effect. Our results highlight the potential of soymilk peptides as anti-aging substances.

Preparation, structural properties, and in vitro and in vivo activities of peptides against dipeptidyl peptidase IV (DPP-IV) and α-glucosidase: a general review

Diabetes is one of the fastest-growing and most widespread diseases worldwide. Approximately 90% of diabetic patients have type 2 diabetes. In 2019, there were about 463 million diabetic patients worldwide. Inhibiting the dipeptidyl peptidase IV (DPP-IV) and α-glucosidase activity is an effective strategy for the treatment of type 2 diabetes. Currently, various anti-diabetic bioactive peptides have been isolated and identified. This review summarizes the preparation methods, structure-effect relationships, molecular binding sites, and effectiveness validation of DPP-IV and α-glucosidase inhibitory peptides in cellular and animal models. The analysis of peptides shows that the DPP-IV inhibitory peptides, containing 2-8 amino acids and having proline, leucine, and valine at their N-terminal and C-terminal, are the highly active peptides. The more active α-glucosidase inhibitory peptides contain 2-9 amino acids and have valine, isoleucine, and proline at the N-terminal and proline, alanine, and serine at the C-terminal.

Copper chelating peptides derived from tilapia (Oreochromis niloticus) skin as tyrosinase inhibitor: Biological evaluation, in silico investigation and in vivo effects

Binuclear copper ions at the active site determine the catalysis of tyrosinase (TYR)¹ whose activity can be inhibited by copper's chelation with other compounds. In this study, tilapia (Oreochromis niloticus) skin was used to generate TYR-inhibitory peptides after being treated by different enzymes and 4 h-Alcaline protease hydrolysate exhibited the highest TYR inhibition and copper chelation. Immobilized metal affinity chromatography was used for purifying copper chelating peptides, among which PFRMY (IC₅₀: 0.43 ± 0.08 mg/mL) and RGFTGM (IC₅₀: 1.61 ± 0.04 mg/mL) exhibited the highest TYR-inhibitory capacity and the lowest docking energy. Both two peptides inhibited TYR in a mixed manner and interacted with key residues binding to copper ions within TYR mainly by hydrogen bonds and hydrophobic forces, while PFRMY had a more compact and stable conjugation with TYR. Zebrafish assay revealed that PFRMY reduced not only melanin synthesis but in vivo TYR activity.

Produksi Hidrolisat Protein Kacang Koro Benguk dengan Aktivitas Penghambat Kerja Enzim Pengkonversi Angiotensin melalui Kombinasi Fermentasi dan Hidrolisis Enzimatik

Mucuna bean (Mucuna pruriens L.) is a legume having high protein content which has the potential as a source of bioactive peptides. One of the bioactive peptides is an angiotensin-converting enzyme (ACE) inhibitor, thus, mucuna beans might be used as a potential source of antihypertensive compounds. This study aimed to increase the functionality of proteins from mucuna beans as ACE inhibitors using a combination of fermentation and enzymatic hydrolysis followed by membrane filtration. The mucuna beans were fermented for 0, 24, 48, 96, and 144 h. The highest ACE inhibitory activity of 54.37%, was obtained by fermentation of the beans at 48 h, with a protein content of 20.82 mg/mL. The 48 h fermented mucuna beans were further hydrolyzed using alcalase or neutrase and subsequently filtered with UF membranes having 20,10 and 5 kDa cut-off. The enzymatic hydrolysis followed by membrane filtration increased the ACE inhibitory activity of mucuna beans. The neutrase hydrolysates resulting from 5 kDa membrane filtration showed the best ACE inhibitory activity (62.96% with a protein content of 10.39 mg/mL). A combination of fermentation and enzymatic hydrolysis followed by filtration using UF-membrane was able to produce ACE inhibitory peptides from mucuna beans. The potential of mucuna beans peptides as ACE inhibitors was due to the presence of negatively charged amino acid residues such as Asp and Glu, positively charged amino acids such as Arg and Lys, and hydrophobic amino acids such as Val, Leu, Ala, and Ile.

Effect of Chicken Egg White-Derived Peptide and Hydrolysates on Abnormal Skin Pigmentation during Wound Recovery

Abnormal skin pigmentation commonly occurs during the wound healing process due to the overproduction of melanin. Chicken egg white (CEW) has long been used to improve skin health. Previous published works had found CEW proteins house bioactive peptides that inhibit tyrosinase, the key enzyme of melanogenesis. The current study aimed to evaluate the anti-pigmentation potential and mechanism of the CEW-derived peptide (GYSLGNWVCAAK) and hydrolysates (CEWH_mono and CEWH_di), using a cell-based model. All of these peptide and hydrolysates inhibited intracellular tyrosinase activity and melanin level up to 45.39 ± 1.31 and 70.01 ± 1.00%, respectively. GYSLGNWVCAAK and CEWH_di reduced intracellular cAMP levels by 13.38 ± 3.65 and 14.55 ± 2.82%, respectively; however, CEWH_mono did not affect cAMP level. Moreover, the hydrolysates downregulated the mRNA expression of melanogenesis-related genes, such as Mitf, Tyr, Trp-1 and Trp-2, but GYSLGNWVCAAK only suppressed Tyr gene expression. Downregulation of the genes may lower the catalytic activities and/or affect the structural stability of TYR, TRP-1 and TRP-2; thus, impeding melanogenesis to cause an anti-pigmentation effect in the cell. Outcomes from the current study could serve as the starting point to understand the underlying complex, multifaceted melanogenesis regulatory mechanism at the cellular level.

Effects of Enzymatic- and Ultrasound-Assisted Extraction on Physicochemical and Antioxidant Properties of Collagen Hydrolysate Fractions from Alaska Pollack (Theragra chalcogramma) Skin

Collagen hydrolysate were extracted from Alaska pollock skin using enzymatic (EAE), ultrasound (UAE), or combination of enzymatic and ultrasound (EAE+UAE) treatment. Control (C) was not treated with enzymatic or ultrasound. The extracts from C, EAE, UAE, and EAE+UAE were fractionated with ≤3, 3-10, 10-30, and ≥30 kDa. Each fraction was evaluated for biological activity and structural properties. All fractions contained high levels of glycine and proline. The ≤3 kDa fraction of control and ultrasound-assisted extracts exhibited the highest antioxidant activity as measured using Trolox equivalent antioxidant capacity, ferric ion reducing antioxidant power, oxygen radical absorbance capacity, and an assay on the inhibition of nitric oxide production by LPS-induced macrophages. The structurally digested collagen was evaluated using FTIR spectra and SDS-PAGE after Alcalase^® and ultrasound treatments. The microstructure of collagen hydrolysate was assessed using SEM microscopy; the surface morphology was altered according to fraction size and extraction conditions. Overall, it was determined that enzyme treatment in combination with ultrasound is the most effective procedure for obtaining digested collagen hydrolysate, which could be used to further improve biotechnological processing for the addition of value to marine production chains in the future.

Collagen Extraction from Animal Skin

Simple Summary

Collagen is useful in many applications including cosmetics, medicine, yarn production and packaging. Collagen can be recovered from skins of animals raised for meat. Here, we review methods for the extraction and purification of collagen from animal skins.

Abstract

Collagen is the most abundant structural protein in animals. It is the major component of skin. It finds uses in cosmetics, medicine, yarn production and packaging. This paper reviews the extraction of collagen from hides of most consumed animals for meat with the focus on literature published since 2000. The different pretreatment and extraction techniques that have been investigated for producing collagen from animal skins are reviewed. Pretreatment by enzymatic, acid or alkaline methods have been used. Extraction by chemical hydrolysis, salt solubilization, enzymatic hydrolysis, ultrasound assisted extraction and other methods are described. Post-extraction purification methods are also explained. This compilation will be useful for anyone wishing to use collagen as a resource and wanting to further improve the extraction and purification methods.

The Hypopigmentation Mechanism of Tyrosinase Inhibitory Peptides Derived from Food Proteins: An Overview

Skin hyperpigmentation resulting from excessive tyrosinase expression has long been a problem for beauty lovers, which has not yet been completely solved. Although researchers are working on finding effective tyrosinase inhibitors, most of them are restricted, due to cell mutation and cytotoxicity. Therefore, functional foods are developing rapidly for their good biocompatibility. Food-derived peptides have been proven to display excellent anti-tyrosinase activity, and the mechanisms involved mainly include inhibition of oxidation, occupation of tyrosinase’s bioactive site and regulation of related gene expression. For anti-oxidation, peptides can interrupt the oxidative reactions catalyzed by tyrosinase or activate an enzyme system, including SOD, CAT, and GSH-Px to scavenge free radicals that stimulate tyrosinase. In addition, researchers predict that peptides probably occupy the site of the substrate by chelating with copper ions or combining with surrounding amino acid residues, ultimately inhibiting the catalytic activity of tyrosinase. More importantly, peptides reduce the tyrosinase expression content, primarily through the cAMP/PKA/CREB pathway, with PI3K/AKT/GSK3β, MEK/ERK/MITF and p38 MAPK/CREB/MITF as side pathways. The objective of this overview is to recap three main mechanisms for peptides to inhibit tyrosinase and the emerging bioinformatic technologies used in developing new inhibitors.

Identification and release kinetics of peptides from tilapia skin collagen during alcalase hydrolysis

Collagen from tilapia skin was extracted and confirmed as type I collagen. Collagen was then hydrolyzed with alcalase for 4 h and the released peptides were identified. The structure-activity relationship of collagen-released peptides showed that proline at position C3 played a key role in improving ACE inhibitory activity, while proline at position C2 had a negative effect. Collagen peptide release kinetics showed that with the extension of time, the number of peptides increased dramatically at first, decreased, and then tended to be stable. This indicated that collagen peptides mainly originated from primary enzymolysis at the first stage and began to undergo secondary hydrolysis in the second stage. Afterwards, secondary enzymolysis was dominant at the third stage and finally remained stable at final two stages. Understanding the pattern of collagen peptide release kinetics might offer a powerful approach in the collagen-peptide food processing industry to better control food safety and quality.

Antihypertensive and Antioxidant Activity of Chia Protein Techno-Functional Extensive Hydrolysates

Twelve high-quality chia protein hydrolysates (CPHs) were produced from chia protein isolate (CPI) in a pilot plant of vegetable proteins. To obtain functional hydrolysate, four CPHs were hydrolyzed by the action of Alcalase, an endoprotease, and the other eight CPHs were hydrolyzed by the action of Flavourzyme, an exoprotease. Alcalase-obtained CPHs showed significant antihypertensive properties particularly, the CPH obtained after 15 min of hydrolysis with Alcalase (CPH15A), which showed a 36.2% hydrolysis degree. In addition, CPH15A increased the antioxidant capacity compared to CPI. The CPH15A physicochemical composition was characterized and compared to chia defatted flour (CDF) and CPI, and its techno-functional properties were determined by in vitro experiments through the analysis of its oil absorption capacity, as well as the capacity and stability of foaming and emulsifying, resulting in an emulsifier and stabilizer better than the intact protein. Therefore, the present study revealed that CPH15A has potent antihypertensive and antioxidant properties and can constitute an effective alternative to other plant protein ingredients sources that are being used in the food industry.

Mimicking the Hierarchical Organization of Natural Collagen: Toward the Development of Ideal Scaffolding Material for Tissue Regeneration

Biological materials found in living organisms, many of which are proteins, feature a complex hierarchical organization. Type I collagen, a fibrous structural protein ubiquitous in the mammalian body, provides a striking example of such a hierarchical material, with peculiar architectural features ranging from the amino acid sequence at the nanoscale (primary structure) up to the assembly of fibrils (quaternary structure) and fibers, with lengths of the order of microns. Collagen plays a dominant role in maintaining the biological and structural integrity of various tissues and organs, such as bone, skin, tendons, blood vessels, and cartilage. Thus, "artificial" collagen-based fibrous assemblies, endowed with appropriate structural properties, represent ideal substrates for the development of devices for tissue engineering applications. In recent years, with the ultimate goal of developing three-dimensional scaffolds with optimal bioactivity able to promote both regeneration and functional recovery of a damaged tissue, numerous studies focused on the capability to finely modulate the scaffold architecture at the microscale and the nanoscale in order to closely mimic the hierarchical features of the extracellular matrix and, in particular, the natural patterning of collagen. All of these studies clearly show that the accurate characterization of the collagen structure at the submolecular and supramolecular levels is pivotal to the understanding of the relationships between the nanostructural/microstructural properties of the fabricated scaffold and its macroscopic performance. Several studies also demonstrate that the selected processing, including any crosslinking and/or sterilization treatments, can strongly affect the architecture of collagen at various length scales. The aim of this review is to highlight the most recent findings on the development of collagen-based scaffolds with optimized properties for tissue engineering. The optimization of the scaffolds is particularly related to the modulation of the collagen architecture, which, in turn, impacts on the achieved bioactivity.

Identification and Characterization of Novel Antioxidant Protein Hydrolysates from Kiwicha (Amaranthus caudatus L.)

Kiwicha (Amaranthus caudatus) is considered one of the few multipurpose pseudocereals for its potential use not only as a source of nutrients and fiber but also for its bioactive compounds. In recent years, antioxidant peptides are commonly used as functional ingredient of food. Herein, a kiwicha protein isolate (KPI), obtained from kiwicha defatted flour (KDF), was hydrolyzed by Bioprotease LA 660, a food-grade endoprotease, under specific conditions. The resulting kiwicha protein hydrolysates (KPHs) were chemically characterized and their digestibility and antioxidant capacity were evaluated by in vitro cell-free experiments owing to their measure of capacity to sequester DPPH free radical and reducing power. KPHs showed higher digestibility and antioxidant capacity than intact proteins into KPI. Therefore, the results shown in this study indicate that KPHs could serve as an adequate source of antioxidant peptides, representing an effective alternative to the generation of functional food.

Use of Alcalase in the production of bioactive peptides: A review

This review aims to cover the uses of the commercially available protease Alcalase in the production of biologically active peptides since 2010. Immobilization of Alcalase has also been reviewed, as immobilization of the enzyme may improve the final reaction design enabling the use of more drastic conditions and the reuse of the biocatalyst. That way, this review presents the production, via Alcalase hydrolysis of different proteins, of peptides with antioxidant, angiotensin I-converting enzyme inhibitory, metal binding, antidiabetic, anti-inflammatory and antimicrobial activities (among other bioactivities) and peptides that improve the functional, sensory and nutritional properties of foods. Alcalase has proved to be among the most efficient proteases for this goal, using different protein sources, being especially interesting the use of the protein residues from food industry as feedstock, as this also solves nature pollution problems. Very interestingly, the bioactivities of the protein hydrolysates further improved when Alcalase is used in a combined way with other proteases both in a sequential way or in a simultaneous hydrolysis (something that could be related to the concept of combi-enzymes), as the combination of proteases with different selectivities and specificities enable the production of a larger amount of peptides and of a smaller size.

Identification of chia seed (Salvia hispanica L.) peptides with enzyme inhibition activity towards skin-aging enzymes

Chia (Salvia hispanica) seed peptides have drawn attention because of their antioxidant, antihypertensive and anti-inflammatory activities, making them ideal candidates for development of cosmeceutical skin products. However, there are no preceding reports that address their aging-related enzyme inhibitory activities. The aim of this study was to investigate the in vitro and in silico inhibitory activity of chia seed peptides towards the main aging-related enzymes. Enzyme-inhibition activity of < 3 kDa chia seed peptides towards collagenase, hyaluronidase, tyrosinase, and elastase was evaluated. Further fractions were obtained by size exclusion chromatography (SEC) and re-tested for enzyme inhibitory activity. Peptide sequences were identified from the most effective fraction and used for in silico analysis. The < 3 kDa peptides exhibited inhibitory activities towards elastase (65.32%, IC₅₀ = 0.43 mg/mL), tyrosinase (58.74%, IC₅₀ = 0.66 mg/mL), hyaluronidase (26.96%, IC₅₀ = 1.28 mg/mL), and collagenase (28.90%, IC₅₀ = 1.41 mg/mL). They showed mixed-type inhibition patterns towards elastase and hyaluronidase, while a non-competitive inhibition pattern was observed towards collagenase and tyrosinase. Fraction II obtained by SEC, showed higher enzyme inhibitory activity. Seven peptides were identified in this fraction (APHWYTN, DQNPRSF, GDAHWAY, GDAHWTY, GDAHWVY, GFEWITF, and KKLKRVYV), which according to in silico analysis, possess 19-29 enzyme-peptide pair interactions towards elastase and three peptide sequences shared homology sequence (GDAHW). These results demonstrate that peptides from chia seeds may contribute in the improvement of skin health by offering protection against aging-related enzymes by preventing degradation of the protein matrix on the skin; however, further in vivo studies are needed to evaluate its actual capability.

Evaluation of Anti-Inflammatory and Atheroprotective Properties of Wheat Gluten Protein Hydrolysates in Primary Human Monocytes

Bioactive protein hydrolysates have been identified in several sources as possible agents in the prevention and treatment of many diseases. A wheat gluten (WG) concentrate was hydrolyzed by Alcalase under specific conditions. The resulting hydrolysates were evaluated by in vitro cell-free experiments leading to the identification of one bioactive WG protein hydrolysate (WGPH), which was used at 50 and 100 μg/mL on primary human monocytes. Reactive oxygen species (ROS) and nitrite levels and RT-qPCR and ELISA techniques were used to analyze the functional activity of WGPH. Our results showed that WGPH hydrolyzed in 45 min (WGPH45A) down-regulated gene expression of Interleukin (IL)-1β, IL-6, IL-17, and Interferon gamma (IFNγ) and reduced cytokine release in lipopolysaccharide (LPS)-stimulated monocytes. In addition, WGPH45A down-regulated gene-related to atherosclerotic onset. Our results suggest that WGPH45A has a potent anti-inflammatory and atheroprotective properties, reducing the expression of gene-related inflammation and atherosclerosis that could be instrumental in maintaining cardiovascular homeostasis.

The Clinical Significance of PPEF1 as a Promising Biomarker and Its Potential Mechanism in Breast Cancer

Background

Breast cancer (BC) is the leading cause of malignancy death in females worldwide. While intense efforts have been made to elucidate the pathogeny, the molecular mechanism of BC remains elusive. Thus, this study aimed to investigate the role of PPEF1 in the progression of BC and further explore the better clinical significance.

Methods

The diagnostic and prognostic values of elevated PPEF1 expression in BC were unveiled via public databases analysis. In addition, Gene Ontology (GO), Gene Set Enrichment Analysis (GSEA) and Protein–protein interaction (PPI) analysis were performed to explore the potential functions and molecular mechanisms of PPEF1 in BC progression. Experimentally, transwell and CCK-8 assays were carried out to estimate the effects of PPEF1 on the BC metastasis. Meanwhile, the differential expressions of PPEF1 in paraffin-embedded tissues and serum samples were, respectively, analyzed by Immunohistochemical (IHC) analysis and enzyme-linked immunosorbent assay (ELISA) kit.

Results

The transcriptional levels of PPEF1 were higher in BC than in normal breast tissues or adjacent normal tissues. Moreover, survival analysis revealed that higher PPEF1 expression was negatively associated with overall survival (OS), all events-free (AE-free) and metastatic recurrence-free (MR-free) survival, and further was an independent risk factor of unfavorable prognosis in BC patients. Additionally, the present study provided the first evidence that PPEF1 participated in multiple biological processes and underly signaling pathways involving in tumorigenesis and development of BC. Furthermore, PPEF1 promotes the BC progression and can be used as a noninvasive diagnostic marker. Noteworthy, the combined determination of serum PPEF1 and traditional tumor markers can enhance diagnostic accuracy thus is of vital importance in the early diagnosis of BC.

Conclusion

PPEF1 exerted a tumorigenic role and involved in molecular mechanism of tumorigenesis in BC which served as a promising biomarker for prognosis and diagnosis.

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

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

Hydrolysed Collagen from Sheepskins as a Source of Functional Peptides with Antioxidant Activity

The extraction and enzymatic hydrolysis of collagen from sheepskins at different times of hydrolysis (0, 10, 15, 20, 30 min, 1, 2, 3 and 4 h) were investigated in terms of amino acid content (hydroxyproline), isoelectric point, molecular weight (Mw) by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) method, viscosity, Fourier-transform infrared (FTIR) spectroscopy, antioxidant capacity by 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays, thermal properties (Differential Scanning Calorimetry) and morphology by scanning electron microscopy (SEM) technique. The kinetics of hydrolysis showed an increase in the protein and hydroxyproline concentration as the hydrolysis time increased to 4 h. FTIR spectra allowed us to identify the functional groups of hydrolysed collagen (HC) in the amide I region for collagen. The isoelectric point shifted to lower values compared to the native collagen precursor. The change in molecular weight and viscosity from time 0 min to 4 h promoted important antioxidant activity in the resulting HC. The lower the Mw, the greater the ability to donate an electron or hydrogen to stabilize radicals. From the SEM images it was evident that HC after 2 h had a porous and spongy structure. These results suggest that HC could be a good alternative to replace HC from typical sources like pigs, cows and fish.

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

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