Marine fish peptides (collagen peptides) compound intake promotes wound healing in rats after cesarean section

Uterine wound healing after caesarean section: A systematic review

The rate of caesarean section (CS) is increasing worldwide. Defects in uterine healing have a major gynaecological and obstetric impact (uterine rupture, caesarean scar defect, caesarean scar pregnancy, placenta accreta spectrum). The complex process of cellular uterine healing after surgery, and specifically after CS, remains poorly understood in contrast to skin wound healing. This literature review on uterine wound healing was mainly based on histological observations, particularly after CS. The primary objective of the review was to examine the effects of CS on uterine tissue at the cellular level, based on histological observations. The secondary objectives were to describe the biomechanical characteristics and the therapies used to improve scar tissue after CS. This review was performed using PRISMA criteria, and PubMed was the data source. The study included all clinical and animal model studies with CS and histological analysis of the uterine scar area (macroscopic, microscopic, immunohistochemical and biomechanical). Twenty studies were included: 10 human and 10 animal models. In total, 533 female humans and 511 female animals were included. Review articles, meeting abstracts, case series, case reports, and abstracts without access to full-text were excluded. The search was limited to studies published in English. No correlation was found between cutaneous and uterine healing. The histology of uterine scars is characterized by disorganized smooth muscle, fibrosis with collagen fibres and fewer endometrial glands. As for skin healing, the initial inflammation phase and mediation of some growth factors (particularly connective tissue growth factor, vascular endothelial growth factor, platelet-derived growth factor, tumour necrosis factor α and tumour necrosis factor β) seem to be essential. This initial phase has an impact on the subsequent phases of proliferation and maturation. Collagen appears to play a key role in the initial granulation tissue to replace the loss of substance. Subsequent maturation of the scar tissue is essential, with a decrease in collagen and smooth muscle restoration. Unlike skin, the glandular structure of uterine tissue could be responsible for the relatively high incidence of healing defects. Uterine scar defects after CS are characterized by an atrophic disorganized endometrium with atypia and a fibroblastic highly collagenic stromal reaction. Concerning immunohistochemistry, one study found a decrease in tumour necrosis factor β in uterine scar defects. No correlation was found between biomechanical characteristics (particularly uterine strength) and the presence of a collagenous scar after CS. Based on the findings of this review, an illustration of current understanding about uterine healing is provided. There is currently no validated prevention of caesarean scar defects. Various treatments to improve uterine healing after CS have been tested, and appeared to have good efficacy in animal studies: alpha lipoic acid, growth factors, collagen scaffolds and mesenchymal stem cells. Further prospective studies are needed.

In Situ Sodium Chloride Cross-Linked Fish Skin Collagen Scaffolds for Functional Hemostasis Materials

Current fish collagen hemostasis for wound healing products is commonly obtained by electrospinning or artificial cross-linking fish collagen fibers which lacks mechanical properties, and biofunctions. Here, a new bio-active fish skin scaffold (FSS) is shown using in situ cross-linked scaleless freshwater fish skin adding adipose-derived stem cells (ASCs)-produced exosomes for hemostasis and wound healing. The structure, pore size, and the thickness of FSS is studied by swelling test, Fourier-transform infrared (FT-IR) spectra, scanning electron microscope (SEM) images, and histological analysis. The biofunctions of the FSS are also tested in vitro and in vivo. FSS keeps two functional layers: The dermis layer collagen forms a sponge like structure after swelling and in situ cross-linking treatments. The pore size of the FSS is ≈152 ± 23.54 µm, which is suitable for cells growing, angiogenesis and ASCs exosomes accelerate wound healing. The fat-rich epidermis layer can keep the wound moisty and clean before completely healed. In vitro and in vivo experimental results indicate that FSS+Exosomes enhances rat skin cavity wound healing. In situ sodium chloride cross-linked FSS+Exosomes provides a new strategy as functional hemostatic dressing scaffold for wound healing.

Toxicity of a 90-day repeated oral dose of a collagen peptide derived from skate (Raja kenojei) skin: a rat model study

Collagen peptides are widely employed as therapeutic materials due to their numerous beneficial properties, including for the following uses: antiaging, antioxidant applications, antibacterial applications, wound healing, tissue engineering, medication delivery, and cosmetics. Although collagen peptides are useful in these applications, to our knowledge, few published studies have been undertaken on their repeated-dose toxicity. We evaluated the possible subchronic toxicity of a collagen peptide derived from skate (Raja kenojei) skin (CPSS) in Sprague-Dawley rats by administering repeated oral doses over 90 days. Rats of both sexes were assigned randomly to one of four experimental groups, respectively receiving 0, 500, 1000, or 2000 mg/kg/day of CPSS. At all doses tested, repeated oral CPSS administration had no treatment-related adverse effects in terms of clinical signs, body weight, food consumption, detailed clinical observation, sensory reactivity, functional assessment, urinalysis, ophthalmic examination, gross pathology, hematology, serum biochemistry, hormone analysis, organ weight, and histopathology. Even though there were some alterations in hematologic parameters, serum biochemistry parameters, organ weight, and histopathological findings, these did not follow a dose-response pattern and were within historical limits for control rats. The oral no-observed-adverse-effect level (NOAEL) of the CPSS was 2000 mg/kg/day for both male and female rats in the applied experimental circumstances, and no target organs were identified.

Food-derived bioactive oligopeptide iron complexes ameliorate iron deficiency anemia and offspring development in pregnant rats

This study aimed to investigate anemia treatment and other potential effects of two food-derived bioactive oligopeptide iron complexes on pregnant rats with iron deficiency anemia (IDA) and their offspring. Rats with IDA were established with a low iron diet and then mated. There were one control group and seven randomly assigned groups of pregnant rats with IDA: Control group [Control, 40 ppm ferrous sulfate (FeSO₄)]; IDA model group (ID, 4 ppm FeSO₄), three high-iron groups (H-FeSO₄, 400 ppm FeSO₄; MCOP-Fe, 400 ppm marine fish oligopeptide iron complex; WCOP-Fe, 400 ppm whey protein oligopeptide iron complex) and three low-iron groups (L-FeSO₄, 40 ppm FeSO₄; MOP-Fe, 40 ppm marine fish oligopeptide iron complex; WOP-Fe, 40 ppm whey protein oligopeptide iron complex). Rats in each group were fed the corresponding special diet during pregnancy until the day of delivery. After different doses of iron supplement, serum hemoglobin, iron, and ferritin levels in rats with IDA were significantly increased to normal levels (P < 0.05). Serum iron levels were significantly lower in two food-derived bioactive oligopeptide low-iron complex groups than in the low FeSO₄ group (P<0.05). Liver malondialdehyde levels were significantly increased in the three high-iron groups compared with the other five groups (P < 0.05), and hemosiderin deposition was observed in liver tissue, indicating that the iron dose was overloaded and aggravated the peroxidative damage in pregnant rats. Liver inflammation was reduced in the three low-iron groups. Tumor necrosis factor α secretion was significantly decreased in all groups with supplemented oligopeptide (P < 0.05), with the concentration of tumor necrosis factor α declining to normal levels in the two whey protein oligopeptide iron complex groups. In the marine fish oligopeptide iron complex groups, body length, tail length, and weight of offspring were significantly increased (P < 0.05) and reached normal levels. Therefore, food-derived bioactive oligopeptide (derived from marine fish skin and milk) iron complexes may be an effective type of iron supplement for pregnancy to improve anemia, as well as reduce the side effects of iron overload, and improve the growth and nutritional status of offspring.

Marine-Derived Collagen as Biomaterials for Human Health

Collagen is a kind of biocompatible protein material, which is widely used in medical tissue engineering, drug delivery, cosmetics, food and other fields. Because of its wide source, low extraction cost and good physical and chemical properties, it has attracted the attention of many researchers in recent years. However, the application of collagen derived from terrestrial organisms is limited due to the existence of diseases, religious beliefs and other problems. Therefore, exploring a wider range of sources of collagen has become one of the main topics for researchers. Marine-derived collagen (MDC) stands out because it comes from a variety of sources and avoids issues such as religion. On the one hand, this paper summarized the sources, extraction methods and characteristics of MDC, and on the other hand, it summarized the application of MDC in the above fields. And on the basis of the review, we found that MDC can not only be extracted from marine organisms, but also from the wastes of some marine organisms, such as fish scales. This makes further use of seafood resources and increases the application prospect of MDC.

Formulation and Evaluation of Helichrysum italicum Essential Oil-Based Topical Formulations for Wound Healing in Diabetic Rats

As proper wound management is crucial to reducing morbidity and improving quality of life, this study evaluated for the first time the wound healing potential of H. italicum essential oil (HIEO) prepared in the form of ointment and gel in streptozotocin-induced diabetic wound models in rats. After creating full-thickness cutaneous wounds, forty-eight diabetic rats were divided into six groups: (1) negative control; (2) positive control; (3) ointment base; (4) gel base; (5) 0.5% HIEO ointment (6) 0.5% HIEO gel. Wound healing potential was determined by the percentage of wound contraction, hydroxyproline content, redox status, and histological observation. A significant decrease in the wound size was observed in animals treated with HIEO formulations compared with other groups. The HIEO groups also showed a higher level of total hydroxyproline content, and more pronounced restitution of adnexal structures with only the underlying muscle defect indicating the incision site. Hence, our results legitimate the traditional data of the pro-healing effect of HIEO because HIEO in both formulations such as gel and ointment exhibited the significant wound repairing effect in the incision wound model.

Collagen-Containing Fish Sidestream-Derived Protein Hydrolysates Support Skin Repair via Chemokine Induction

Restoring homeostasis following tissue damage requires a dynamic and tightly orchestrated sequence of molecular and cellular events that ensure repair and healing. It is well established that nutrition directly affects skin homeostasis, while malnutrition causes impaired tissue healing. In this study, we utilized fish sidestream-derived protein hydrolysates including fish collagen as dietary supplements, and investigated their effect on the skin repair process using a murine model of cutaneous wound healing. We explored potential differences in wound closure and histological morphology between diet groups, and analyzed the expression and production of factors that participate in different stages of the repair process. Dietary supplementation with fish sidestream-derived collagen alone (Collagen), or in combination with a protein hydrolysate derived from salmon heads (HSH), resulted in accelerated healing. Chemical analysis of the tested extracts revealed that Collagen had the highest protein content and that HSH contained the great amount of zinc, known to support immune responses. Indeed, tissues from mice fed with collagen-containing supplements exhibited an increase in the expression levels of chemokines, important for the recruitment of immune cells into the damaged wound region. Moreover, expression of a potent angiogenic factor, vascular endothelial growth factor-A (VEGF-A), was elevated followed by enhanced collagen deposition. Our findings suggest that a 5%-supplemented diet with marine collagen-enriched supplements promotes tissue repair in the model of cutaneous wound healing, proposing a novel health-promoting use of fish sidestreams.

Identification of a novel collagen-like peptide by high-throughput screening for effective wound-healing therapy

Tissue regeneration and wound healing are still serious clinical complications globally and lack satisfactory cures. Inspired by the impressive regeneration ability of the post-injury earthworms and their widely accepted medicinal properties, we screened and identified a novel collagen-like peptide from the amputated earthworms using high-throughput techniques, including transcriptomics, proteomics, and mass spectrum. The identified collagen-like peptide col4a1 was cloned and expressed to comprehensively investigate the wound healing effect and underlying mechanism. It exerted significant effects on wound healing both in vitro and in vivo, including enhanced viability, proliferation, migration of fibroblasts, granulation, and collagen deposition. Moreover, the col4a1 functioned via binding with integrin α₂β₁ and upregulating the RAS/MAPK signaling pathway. This work demonstrates that the novel collagen-like peptide col4a1 obtained from the amputated earthworms enables enhanced wound healing and provides new opportunities for wound care.