A Double-Blind, Randomized Trial Shows the Role of Zonal Priming and Direct Topical Application of Epigallocatechin-3-Gallate in the Modulation of Cutaneous Scarring in Human Skin

Proteoglycan 4 (PRG4) treatment improves skin wound healing in a porcine model

Proteoglycan 4 (PRG4) is a boundary lubricant originally identified in articular cartilage and has been since shown to have immunomodulation and antifibrotic properties. Previously, we have demonstrated that recombinant human (rh)PRG4 treatment accelerates auricular cartilage injury closure through an inhibition of the fibrotic response, and promotion of tissue regeneration in mice. The purpose of the current study was to examine the effects of rhPRG4 treatment (vs. a DMSO carried control) on full-thickness skin wound healing in a preclinical porcine model. Our findings suggest that while rhPRG4 did not significantly accelerate nor impede full-thickness skin wound closure, it did improve repair quality by decreasing molecular markers of fibrosis and increasing re-vascularization. We also demonstrated that rhPRG4 treatment increased dermal adipose tissue during the healing process specifically by retaining adipocytes in the wound area but did not inhibit lipolysis. Overall, the results of the current study have demonstrated that rhPRG4 acts as antifibrotic agent and regulates dermal adipose tissue during the healing processes resulting in a tissue with a trajectory that more resembles the native skin vs. a fibrotic patch. This study provides strong rationale to examine if rhPRG4 can improve regeneration in human wounds.

Epigallocatechin-3-gallate promotes wound healing response in diabetic mice by activating keratinocytes and promoting re-epithelialization

Type 2 diabetes (T2D) is a metabolic disorder that causes numerous complications including impaired wound healing and poses a significant challenge for the management of diabetic patients. Epigallocatechin-3-gallate (EGCG) is a natural polyphenol that exhibits anti-inflammatory and anti-oxidative benefits in skin wounds, however, the direct effect of EGCG on epidermal keratinocytes, the primary cells required for re-epithelialization in wound healing remains unknown. Our study aims to examine the underlying mechanisms of EGCG's ability to promote re-epithelialization and wound healing in T2D-induced wounds. Murine models of wound healing in T2D were established via feeding high-fat high-fructose diet (HFFD) and the creation of full-thickness wounds. Mice were administered daily with EGCG or vehicle to examine the wound healing response and underlying molecular mechanisms of EGCG's protective effects. Systemic administration of EGCG in T2D mice robustly accelerated the wound healing response following injury. EGCG induced nuclear translocation of nuclear factor erythroid 2-related factor 2 (NRF2) and promoted cytokeratin 16 (K16) expression to activate epidermal keratinocytes and robustly promoted re-epithelialization of wounds in diabetic mice. Further, EGCG demonstrated high binding affinity with Kelch-like ECH-associated protein 1 (KEAP1), thereby inhibiting KEAP1-mediated degradation of NRF2. Our findings provide important evidence that EGCG accelerates the wound healing response in diabetic mice by activating epidermal keratinocytes, thereby promoting re-epithelialization of wounds via K16/NRF2/KEAP1 signaling axis. These mechanistic insights into the protective effects of EGCG further suggest its therapeutic potential as a promising drug for treating chronic wounds in T2D.

Decellularized human amniotic membrane loaded with epigallocatechin-3-gallate accelerated diabetic wound healing

Diabetic wounds, as one of the most important complications of diabetes, face many challenges in treatment. Herein we investigated whether decellularized human amniotic membrane (dAM) loaded with epigallocatechin-3-gallate (EGCG) could promote healing in diabetic rats. Sixty diabetic rats were randomly planned into the untreated group, dAM group, EGCG group, and dAM + EGCG group. On days 7, 14, and 21, five rats from each group were sampled for stereological, molecular, and tensiometrical assessments. Our finding revealed that the wound closure rate, the total volumes of new epidermis and dermis, the numerical densities of fibroblasts, blood vessels, collagen density as well as tensiometrical parameters of the healed wounds were considerably increased in the treated groups than in the untreated group, and these changes were more obvious in the dAM + EGCG ones. Furthermore, the expression of TGF-β, bFGF, and VEGF genes were significantly upregulated in all treated groups compared to the untreated group and were greater in the dAM + EGCG group. This is while expression of TNF-α and IL-1β, as well as cell numerical densities of neutrophils and macrophages decreased more considerably in the dAM + EGCG group in comparison to the other groups. In conclusion, it was found that using both dAM transplantation and EGCG has more effect on diabetic wound healing.

Mast Cell Activation Syndrome Update-A Dermatological Perspective

Mast cells (MCs) are infamous for their role in potentially fatal anaphylaxis reactions. In the last two decades, a more complex picture has emerged, as it has become obvious that MCs are much more than just IgE effectors of anaphylaxis. MCs are defenders against a host of infectious and toxic aggressions (their interactions with other components of the immune system are not yet fully understood) and after the insult has ended, MCs continue to play a role in inflammation regulation and tissue repair. Unfortunately, MC involvement in pathology is also significant. Apart from their role in allergies, MCs can proliferate clonally to produce systemic mastocytosis. They have also been implicated in excessive fibrosis, keloid scaring, graft rejection and chronic inflammation, especially at the level of the skin and gut. In recent years, the term MC activation syndrome (MCAS) was proposed to account for symptoms caused by MC activation, and clear diagnostic criteria have been defined. However, not all authors agree with these criteria, as some find them too restrictive, potentially leaving much of the MC-related pathology unaccounted for. Here, we review the current knowledge on the physiological and pathological roles of MCs, with a dermatological emphasis, and discuss the MCAS classification.

The Potential of Flavonoids and Flavonoid Metabolites in the Treatment of Neurodegenerative Pathology in Disorders of Cognitive Decline

Flavonoids are a biodiverse family of dietary compounds that have antioxidant, anti-inflammatory, antiviral, and antibacterial cell protective profiles. They have received considerable attention as potential therapeutic agents in biomedicine and have been widely used in traditional complimentary medicine for generations. Such complimentary medical herbal formulations are extremely complex mixtures of many pharmacologically active compounds that provide a therapeutic outcome through a network pharmacological effects of considerable complexity. Methods are emerging to determine the active components used in complimentary medicine and their therapeutic targets and to decipher the complexities of how network pharmacology provides such therapeutic effects. The gut microbiome has important roles to play in the generation of bioactive flavonoid metabolites retaining or exceeding the antioxidative and anti-inflammatory properties of the intact flavonoid and, in some cases, new antitumor and antineurodegenerative bioactivities. Certain food items have been identified with high prebiotic profiles suggesting that neutraceutical supplementation may be beneficially employed to preserve a healthy population of bacterial symbiont species and minimize the establishment of harmful pathogenic organisms. Gut health is an important consideration effecting the overall health and wellbeing of linked organ systems. Bioconversion of dietary flavonoid components in the gut generates therapeutic metabolites that can also be transported by the vagus nerve and systemic circulation to brain cell populations to exert a beneficial effect. This is particularly important in a number of neurological disorders (autism, bipolar disorder, AD, PD) characterized by effects on moods, resulting in depression and anxiety, impaired motor function, and long-term cognitive decline. Native flavonoids have many beneficial properties in the alleviation of inflammation in tissues, however, concerns have been raised that therapeutic levels of flavonoids may not be achieved, thus allowing them to display optimal therapeutic effects. Dietary manipulation and vagal stimulation have both yielded beneficial responses in the treatment of autism spectrum disorders, depression, and anxiety, establishing the vagal nerve as a route of communication in the gut-brain axis with established roles in disease intervention. While a number of native flavonoids are beneficial in the treatment of neurological disorders and are known to penetrate the blood–brain barrier, microbiome-generated flavonoid metabolites (e.g., protocatechuic acid, urolithins, γ-valerolactones), which retain the antioxidant and anti-inflammatory potency of the native flavonoid in addition to bioactive properties that promote mitochondrial health and cerebrovascular microcapillary function, should also be considered as potential biotherapeutic agents. Studies are warranted to experimentally examine the efficacy of flavonoid metabolites directly, as they emerge as novel therapeutic options.

In Vitro, Ex Vivo, and In Vivo Approaches for Investigation of Skin Scarring: Human and Animal Models

Significance: The cutaneous repair process naturally results in different types of scarring that are classified as normal or pathological. Affected individuals are often affected from an esthetic, physical (functional), and psychosocial perspective. The distinct nature of scarring in humans, particularly the formation of pathological scars, makes the study of skin scarring a challenge for researchers in this area. Several established experimental models exist for studying scar formation. However, the increasing development and validation of newly emerging models have made it possible to carry out studies focused on different variables that influence this unique process. Recent Advances: Experimental models such as in vitro, ex vivo, and in vivo models have obtained different degrees of success in the reproduction of the scar formation in its native milieu and true environment. These models also differ in their ability to elucidate the molecular, cellular, and structural mechanisms involved in scarring, as well as for testing new agents and approaches for therapies. The models reviewed here, including cells derived from human skin and in vivo animal models, have contributed to the advancement of skin scarring research. Critical Issues and Future Directions: The absence of experimental models that faithfully reproduce the typical characteristics of the different types of human skin scars makes the improvement of validated models and the establishment of new ones a critical unmet need. The fields of wound healing research combined with tissue engineering have offered newer alternatives for experimental studies with the potential to provide clinically useful knowledge about scar formation.

Polyphenol-driven facile assembly of a nanosized acid fibroblast growth factor-containing coacervate accelerates the healing of diabetic wounds

Diabetic wounds are challenging to heal due to complex pathogenic abnormalities. Routine treatment with acid fibroblast growth factor (aFGF) is widely used for diabetic wounds but hardly offers a satisfying outcome due to its instability. Despite the emergence of various nanoparticle-based protein delivery approaches, it remains challenging to engineer a versatile delivery system capable of enhancing protein stability without the need for complex preparation. Herein, a polyphenol-driven facile assembly of nanosized coacervates (AE-NPs) composed of aFGF and Epigallocatechin-3-gallate (EGCG) was constructed and applied in the healing of diabetic wounds. First, the binding patterns of EGCG and aFGF were predicted by molecular docking analysis. Then, the characterizations demonstrated that AE-NPs displayed higher stability in hostile conditions than free aFGF by enhancing the binding activity of aFGF to cell surface receptors. Meanwhile, the AE-NPs also had a powerful ability to scavenge reactive oxygen species (ROS) and promote angiogenesis, which significantly accelerated full-thickness excisional wound healing in diabetic mice. Besides, the AE-NPs suppressed the early scar formation by improving collagen remodeling and the mechanism was associated with the TGF-β/Smad signaling pathway. Conclusively, AE-NPs might be a potential and facile strategy for stabilizing protein drugs and achieving the scar-free healing of diabetic wounds. STATEMENT OF SIGNIFICANCE: Diabetic chronic wound is among the serious complications of diabetes that eventually cause the amputation of limbs. Herein, a polyphenol-driven facile assembly of nanosized coacervates (AE-NPs) composed of aFGF and EGCG was constructed. The EGCG not only acted as a carrier but also possessed a therapeutic effect of ROS scavenging. The AE-NPs enhanced the binding activity of aFGF to cell surface receptors on the cell surface, which improved the stability of aFGF in hostile conditions. Moreover, AE-NPs significantly accelerated wound healing and improved collagen remodeling by regulating the TGF-β/Smad signaling pathway. Our results bring new insights into the field of polyphenol-containing nanoparticles, showing their potential as drug delivery systems of macromolecules to treat diabetic wounds.

EGCG inhibits hypertrophic scar formation in a rabbit ear model

OBJECTIVE

Hypertrophic scarring is a common skin fibro-proliferative disease, but currently there has no satisfactory drugs for anti-scar treatments. Previous study showed that epigallocatechin gallate (EGCG), the main catechin in green tea, improved wound healing and tissue fibrosis in both rats and mice. In the present study, the therapeutic effects of EGCG on hypertrophic scar were analyzed using a rabbit ear hypertrophic scar model.

MATERIALS

A rabbit ear model of hypertrophic scarring was used. DMSO, 0.5 mg EGCG/wound, 1.0 mg EGCG/wound or triamcinolone were injected subcutaneously once a week for 4 weeks. The scar elevation index (SEI) was measured using HE staining images, the collagen fibers were examined by Masson' trichrome staining images, and the number of capillaries in hypertrophic scar were calculated by CD31 staining images. The mRNA levels in the scar tissues were detected by quantitative real-time polymerase chain reaction (qRT-PCR).

RESULTS

Gross observation and histological evaluation showed the inhibitory effects of EGCG on hypertrophic scar formation at both doses, and decreased scar height and SEI were detected. EGCG also attenuated the mean collagen area fraction and decreased the number of capillaries in scar tissues. qRT-PCR revealed that EGCG significantly inhibited the mRNA expression of TGF-β1, Col I, Col III, α-SMA, and eNOS.

CONCLUSION

EGCG may serve as a useful candidate therapeutic drug for hypertrophic scar via inhibiting fibrotic gene expression and suppressing angiogenesis.

Skin scarring: Latest update on objective assessment and optimal management

Although skin scarring is considered by some to be a minor, unavoidable consequence in response to skin injury, for many patients, cosmetically unsightly scars may cause uncomfortable symptoms and loss of function plus significant psycho-social distress. Despite their high prevalence and commonality, defining skin scars and their optimal management has proven problematic. Therefore, a literature search to assess the current evidence-base for scarring treatment options was conducted, and only those deemed Levels of Evidence 1 or 2 were included. Understanding the spectrum of skin scarring in the first instance is imperative, and is mainly comprised of four distinct endotypes; Stretched (flat), Contracted, Atrophic, and Raised for which the acronym S.C.A.R. may be used. Traditionally, scar assessment and response to therapy has employed the use of subjective scar scales, although these are now being superseded by non-invasive, objective and quantitative measurement devices. Treatment options will vary depending on the specific scar endotype, but fall under one of 3 main categories: (1) Leave alone, (2) Non-invasive, (3) Invasive management. Non-invasive (mostly topical) management of skin scarring remains the most accessible, as many formulations are over-the-counter, and include silicone-based, onion extract-based, and green tea-based, however out of the 52 studies identified, only 28 had statistically significant positive outcomes. Invasive treatment options includes intralesional injections with steroids, 5-FU, PDT, and laser with surgical scar excision as a last resort especially in keloid scar management unless combined with an appropriate adjuvant therapy. In summary, scar management is a rapidly changing field with an unmet need to date for a structured and validated approach.

The potential of functionalized dressing releasing flavonoids facilitates scar-free healing

Scars are pathological marks left after an injury heals that inflict physical and psychological harm, especially the great threat to development and aesthetics posed by oral and maxillofacial scars. The differential expression of genes such as transforming growth factor-β, local adherent plaque kinase, and yes-related transcriptional regulators at infancy or the oral mucosa is thought to be the reason of scarless regenerative capacity after tissue defects. Currently, tissue engineering products for defect repair frequently overlook the management of postoperative scars, and inhibitors of important genes alone have negative consequences for the organism. Natural flavonoids have hemostatic, anti-inflammatory, antioxidant, and antibacterial properties, which promote wound healing and have anti-scar properties by interfering with the transmission of key signaling pathways involved in scar formation. The combination of flavonoid-rich drug dressings provides a platform for clinical translation of compounds that aid in drug disintegration, prolonged release, and targeted delivery. Therefore, we present a review of the mechanisms and effects of flavonoids in promoting scar-free regeneration and the application of flavonoid-laden dressings.

A Green Tea Containing Skincare System Improves Skin Health and Beauty in Adults: An Exploratory Controlled Clinical Study

Skin dryness, fine lines and wrinkles, red spots, red vasculature, and porphyrin count are common indicators of skin health and beauty. The skincare system in this study contains scientifically validated ingredients such as fermented green tea (Camellia sinensis) water, niacinamide, antioxidants, and a variety of natural plant extracts. The purpose of this study was to evaluate the effectiveness of this skincare system in improving facial-skin health and beauty. Twenty-six healthy adults, both female and male, aged 18–54 and of all skin types and tones, were included in the study and participated as either the active or the control group (competitor product) using designated topical products for 30 days. Skin moisture, fine lines and wrinkles, porphyrin count, red spots, and red vasculature count were measured through high-quality photography, Visia® complexion analysis, FitSkin® skin analysis, and survey questions on day 0, day 8, and day 30. Significant improvements were observed in facial moisture, red-spot count, red vasculature count, and porphyrin count on day 30 in comparison with the control group. Non-significant improvements were observed in pores, skin texture, and wrinkles. With extensive well-documented functional ingredients, the studied skincare system used daily may significantly improve key areas of skin health and beauty.

Nanoencapsulation of Tea Catechins for Enhancing Skin Absorption and Therapeutic Efficacy

Tea catechins are a group of flavonoids that show many bioactivities. Catechins have been extensively reported as a potential treatment for skin disorders, including skin cancers, acne, photoaging, cutaneous wounds, scars, alopecia, psoriasis, atopic dermatitis, and microbial infection. In particular, there has been an increasing interest in the discovery of cosmetic applications using catechins as the active ingredient because of their antioxidant and anti-aging activities. However, active molecules with limited lipophilicity have difficulty penetrating the skin barrier, resulting in low bioavailability. Nevertheless, topical application is a convenient method for delivering catechins into the skin. Nanomedicine offers an opportunity to improve the delivery efficiency of tea catechins and related compounds. The advantages of catechin-loaded nanocarriers for topical application include high catechin loading efficiency, sustained or prolonged release, increased catechin stability, improved bioavailability, and enhanced accumulation or targeting to the nidus. Further, various types of nanoparticles, including liposomes, niosomes, micelles, lipid-based nanoparticles, polymeric nanoparticles, liquid crystalline nanoparticles, and nanocrystals, have been employed for topical catechin delivery. These nanoparticles can improve catechin permeation via close skin contact, increased skin hydration, skin structure disorganization, and follicular uptake. In this review, we describe the catechin skin delivery approaches based on nanomedicine for treating skin disorders. We also provide an in-depth description of how nanoparticles effectively improve the skin absorption of tea catechins and related compounds, such as caffeine. Furthermore, we summarize the possible future applications and the limitations of nanocarriers for topical delivery at the end of this review article.

Amazonian Guarana- and Açai-Conjugated Extracts Improve Scratched Fibroblast Healing and Eisenia fetida Surgical Tail Amputation by Modulating Oxidative Metabolism

Background

Previous studies have suggested that guarana (Paullinia cupana) and açai (Euterpe oleracea) have antioxidant, anti-inflammatory, and proliferative properties, indicating their potential therapeutic action in wound healing. We produced a conjugated guarana-açai (GA) extract and tested its healing action on earthworms (Eisenia fetida) subjected to tail amputation by surgical incision.

Methods

Extract from roasted guarana seeds and fresh açai seed berries was produced. The antioxidant and genoprotective capacity of GA extract was tested. The concentration with the most remarkable healing potential was used in subsequent tests. The last three posterior segments of the clitellate earthworm tail reared under standardized conditions were surgically amputated. Next, topical PBS or GA extract was applied to the surgical wound. The rate of cell migration and tissue regeneration at the local wound site was histologically evaluated after the procedure. Expression of the SOX4 gene that acts in epithelial-to-mesenchymal transition was determined by RT-qPCR.

Results

Sixteen bioactive molecules, including some previously described substances, were identified. All tested concentrations exhibited antioxidant and genoprotective effects. The GA extract accelerated the healing processes as observed through macroscopic and histological analyses and increased expression of SOX4.

Conclusion

The GA extract has a potential role in the healing of surgically induced wounds.

Controlling Inflammation Pre-Emptively or at the Time of Cutaneous Injury Optimises Outcome of Skin Scarring

Inflammation plays an active role during the wound healing process. There is a direct association between the extent of injury as well as inflammation and the amount of subsequent cutaneous scarring. Evidence to date demonstrates that high levels of inflammation are associated with excessive dermal scarring and formation of abnormal pathological scars such as keloids and hypertrophic scars. In view of the multiple important cell types being involved in the inflammatory process and their influence on the extent of scar formation, many scar therapies should aim to target these cells in order to control inflammation and by association help improve scar outcome. However, most current treatment strategies for the management of a newly formed skin scar often adopt a watch-and-wait approach prior to commencing targeted anti-inflammatory therapy. Moreover, most of these therapies have been evaluated in the remodelling phase of wound healing and the evaluation of anti-inflammatory treatments at earlier stages of healing have not been fully explored and remain limited. Taken together, in order to minimise the risk of developing a poor scar outcome, it is clear that adopting an early intervention prior to skin injury would be optimal, however, the concept of pre-emptively priming the skin prior to injury has not yet been thoroughly evaluated. Therefore, the aim of this review was to evaluate the available literature regarding scar therapies that aim to target inflammation which are commenced prior to when a scar is formed or immediately after injury, with a particular focus on the role of pre-emptive priming of skin prior to injury in order to control inflammation for the prevention of poor scarring outcome.

Noninvasive Objective Tools for Quantitative Assessment of Skin Scarring

Significance: Many treatments are utilized in the management of skin scarring; however, difficulties arise due to the high rates of recurrence and the identification of treatment efficacy in each patient, in particular, in the case of raised dermal scarring. Therefore, evaluation of treatments and the provision of objective scar assessment pre-therapy and post-therapy is of paramount importance to identify changes in scar characteristics using noninvasive devices. Recent Advances: There have been a number of emerging noninvasive objective quantitative devices, which assess specific scar parameters such as pliability, volume, color, perfusion, and depth. These can include three-dimensional imaging, optical coherence tomography, in vivo confocal microscopy, full-field laser perfusion imaging, and spectrophotometric intracutaneous analysis. Critical Issues: Clinical assessment and grading scales are most commonly used to assess scarring; however, there is a need for more objective quantitative measures to monitor their maturation and response to therapy. Currently, there is no consensus as to which objective measuring device is most optimal when assessing skin scarring. There is a need for a predictor tool that allows early implementation of treatment and addresses diagnosis, therapy, and prognosis. Future Directions: Validation of noninvasive objective scar assessment tools is essential as well as further development of technologies. There are currently more modalities that assess physical scar characteristics and only few that measure the physiological parameters. Therefore, the development of a technology that quantifies the metabolic and cellular activity in skin scars is necessary to allow for bespoke strategies for each patient.

Classification of Distinct Endotypes in Human Skin Scarring: S.C.A.R.-A Novel Perspective on Dermal Fibrosis

Significance: Skin scarring is a permanent, irreversible end point of cutaneous injury. However, not everyone will acquire the same exact scar type. Skin scarring is generally recognized as complex with significant variability in individuals' scar type and response to treatment. Despite these tangible differences in treatment response, to date there has been no simplified approach in defining spectrum of skin scarring in relation to prediction and outcome post-treatment. Thus, in this study we propose that skin scarring consists of distinct endotypes, which is characterized by their specific pathology. Four distinct scar endotypes can be observed: (1) Stretched (flat), (2) Contracted, (3) Atrophic (depressed), and (4) Raised scarring, which can be abbreviated to S.C.A.R. endotypes. Each of these endotypes can certainly include subphenotypes and each phenotype can be present in more than one endotype. To define these endotypes, we also present a structured approach in assessment of all relevant parameters in skin scar evaluation including clinical (scar symptoms and signs) and nonclinical parameters (device measurements of structural, mechanical, and physiological properties of scars as well as gene and protein laboratory studies). Recent Advances: Scars can be phenotypically characterized based on a multitude of parameters assessed; however, not all scar types will share all the same characteristics. This leads to the question of whether skin scarring is a single disease entity with varying phenotypic characteristics or should be classed as several disease entities that have certain similar parameters. We suggest the latter and propose distinct scarring phenotypes arise mainly owing to genetic and environmental susceptibilities associated with the development of each specific scar endotype. Characteristic features of skin scarring, however, can be objectively and quantitively evaluated and used as an aid in the theranostic goal-directed management of scarring. Critical Issues: The concept of identifying different endotypes is key in formulating personalized treatments with improved outcomes beyond what is achieved with current nonspecific approaches in scar management. This approach has gained interest and significant traction in several other medical conditions including asthma, rheumatoid arthritis, and atopic dermatitis. Future Directions: To begin identifying distinct endotypic features in skin scarring, it is important to have a better understanding of underlying pathological mechanisms leading to further insight into the heterogeneous nature of skin scarring endotypes. This approach may lead to improved theranostic outcomes and further understanding of the pathophysiology of the complex nature of human skin scarring.

Enhanced OXER1 expression is indispensable for human cancer cell migration

OXER1 is a recently identified receptor, binding the arachidonic acid metabolic product 5-oxo-ETE, considered an inflammatory receptor, implicated in chemoattraction of circulating mononuclear cells, Ca²⁺ surge in neutrophils, inflammation and cancer. Recently, we have shown that OXER1 is also a membrane androgen receptor in various cancer tissues. It was reported that the presence of OXER1 in leucocytes and the production and release of 5-oxo-ETE by wounded tissues is a wound sensing mechanism, leading to lymphocyte attraction. In view of the similarity of hallmarks of cancer and wound healing, we have explored the role of OXER1 and its endogenous ligand in the control of cell migration of human cancer epithelial cells (DU-145, T47D and Hep3B), mimicking the activation/migration phase of healing. We show that OXER1 is up-regulated only at the leading edge of the wound and its expression is up-regulated by its ligand 5-oxo-ETE, in a time-related manner. Knock-down of OXER1 or inhibition of 5-oxo-ETE synthesis led to decreased migration of cells and a prolongation of healing, in culture prostate cancer cell monolayers, with a substantial modification of actin cytoskeleton and a decreased filopodia formation. Inhibition of cell migration is a phenomenon mediated by G_βγ OXER1 mediated actions. These results provide a novel mechanism of OXER1 implication in cancer progression and might be of value for the design of novel OXER1 antagonists.

The antimicrobial and immunomodulatory effects of Ionophores for the treatment of human infection

Ionophores are a diverse class of synthetic and naturally occurring ion transporter compounds which demonstrate both direct and in-direct antimicrobial properties against a broad panel of bacterial, fungal, viral and parasitic pathogens. In addition, ionophores can regulate the host-immune response during communicable and non-communicable disease states. Although the clinical use of ionophores such as Amphotericin B, Bedaquiline and Ivermectin highlight the utility of ionophores in modern medicine, for many other ionophore compounds issues surrounding toxicity, bioavailability or lack of in vivo efficacy studies have hindered clinical development. The antimicrobial and immunomodulating properties of a range of compounds with characteristics of ionophores remain largely unexplored. As such, ionophores remain a latent therapeutic avenue to address both the global burden of antimicrobial resistance, and the unmet clinical need for new antimicrobial therapies. This review will provide an overview of the broad-spectrum antimicrobial and immunomodulatory properties of ionophores, and their potential uses in clinical medicine for combatting infection.

Beneficial Effects of Green Tea EGCG on Skin Wound Healing: A Comprehensive Review

Epigallocatechin gallate (EGCG) is associated with various health benefits. In this review, we searched current work about the effects of EGCG and its wound dressings on skin for wound healing. Hydrogels, nanoparticles, micro/nanofiber networks and microneedles are the major types of EGCG-containing wound dressings. The beneficial effects of EGCG and its wound dressings at different stages of skin wound healing (hemostasis, inflammation, proliferation and tissue remodeling) were summarized based on the underlying mechanisms of antioxidant, anti-inflammatory, antimicrobial, angiogenesis and antifibrotic properties. This review expatiates on the rationale of using EGCG to promote skin wound healing and prevent scar formation, which provides a future clinical application direction of EGCG.

Glycosaminoglycans: Sweet as Sugar Targets for Topical Skin Anti-Aging

Glycosaminoglycans (GAGs) are long, linear polysaccharides comprised of repeating disaccharide units with pleiotropic biological functions, with the non-sulfated GAG hyaluronic acid (HA), and sulfated GAGs dermatan sulfate, chondroitin sulfate, heparan sulfate, keratan sulfate, and to a lesser extent heparin all being expressed in skin. Their ability to regulate keratinocyte proliferation and differentiation, inflammatory processes and extracellular matrix composition and quality demonstrates their critical role in regulating skin physiology. Similarly, the water-binding properties of GAGs and structural qualities, particularly for HA, are crucial for maintaining proper skin form and hydration. The biological importance of GAGs, as well as extensive evidence that their properties and functions are altered in both chronological and extrinsic skin aging, makes them highly promising targets to improve cosmetic skin quality. Within the present review, we examine the cutaneous biological activity of GAGs alongside the protein complexes they form called proteoglycans and summarize the age-related changes of these molecules in skin. We also examine current topical interventional approaches to modulate GAGs for improved skin quality such as direct exogenous administration of GAGs, with a particular interest in strategies targeted at potentiating GAG levels in skin through either attenuating GAG degradation or increasing GAG production.

Pharmacological actions and underlying mechanisms of Catechin: A review

BACKGROUND

Catechin is a phytochemical and is a major component of our daily use beverages, which has shown great potential in improving general health and fighting against several medical conditions. Clinical studies have confirmed its effectiveness in conditions ranging from acute upper respiratory tract infection, neuroprotection, to cardio-protection effects. Though most studies relate their potential to anti-oxidative action and radical scavenging action, still the mechanism of action is not clearly understood.

OBJECTIVE

The present review article is focused on addressing various pharmacological actions and underlying mechanisms of catechin. Additionally, we will try to figure out the major adverse effect and success in trials with catechin and lead to a conclusion for its effectiveness.

METHODS

This review article is based on the recent/ most cited papers of PubMed and Scopus databases.

DESCRIPTION

Catechin can regulate Nrf2 and NFkB pathways in ways that impact oxidative stress and inflammation by influencing gene expression. Other pathways like MAPKs and COMT and receptor tyrosine kinase are also affected by catechin and EGCG that alter their action and barge the cellular activity. This review article explored the structural aspect of catechin and its different isomers and analogs. It also evaluated its various therapeutic and pharmacological arrays .

CONCLUSION

Catechin and its stereo-isomers have shown their effectiveness as anti-inflammatory, anti-diabetic, anti-cancer, anti-neuroprotective, bactericidal, memory enhancer, anti-arthritis, and hepato-protective mainly through its activity to alter the pathway by NF-κB, Nrf-2, TLR4/NF-κB, COMT, and MAPKs.

Perspective on the application of medicinal plants and natural products in wound healing: A mechanistic review

Wound is defined as any injury to the body such as damage to the epidermis of the skin and disturbance to its normal anatomy and function. Since ancient times, the importance of wound healing has been recognized, and many efforts have been made to develop novel wound dressings made of the best material for rapid and effective wound healing. Medicinal plants play a great role in the wound healing process. In recent decades, many studies have focused on the development of novel wound dressings that incorporate medicinal plant extracts or their purified active compounds, which are potential alternatives to conventional wound dressings. Several studies have also investigated the mechanism of action of various herbal medicines in wound healing process. This paper attempts to highlight and review the mechanistic perspective of wound healing mediated by plant-based natural products. The findings showed that herbal medicines act through multiple mechanisms and are involved in various stages of wound healing. Some herbal medicines increase the expression of vascular endothelial growth factor (VEGF) and transforming growth factor-β (TGF-β) which play important role in stimulation of re-epithelialization, angiogenesis, formation of granulation tissue, and collagen fiber deposition. Some other wound dressing containing herbal medicines act as inhibitor of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and inducible nitric oxide synthase (iNOS) protein expression thereby inducing antioxidant and anti-inflammatory properties in various phases of the wound healing process. Besides the growing public interest in traditional and alternative medicine, the use of herbal medicine and natural products for wound healing has many advantages over conventional medicines, including greater effectiveness due to diverse mechanisms of action, antibacterial activity, and safety in long-term wound dressing usage.

Pre-Emptive Priming of Human Skin Improves Cutaneous Scarring and Is Superior to Immediate and Delayed Topical Anti-Scarring Treatment Post-Wounding: A Double-Blind Randomised Placebo-Controlled Clinical Trial

The concept of pre-emptive priming of skin pre-surgery offers a novel approach in optimizing cutaneous scarring outcome. We previously showed an anti-scarring topical (epigallocatechin-3-gallate (EGCG)) is effective in improving skin scarring when applied post-surgery. The objective was to deliver an active compound at the optimal time in order to maximize its impact and improve cutaneous scarring. Therefore, pre-emptive application of anti-scarring topical pre-surgery compared with post-surgery can potentially be superior on scarring outcome. This double-blinded randomized placebo-controlled trial compares the effects of pre-emptive priming of skin with an anti-scarring topical pre-surgery versus post-surgery. Healthy volunteers (n = 40) were split into 4-groups; each undergoing different modes of application versus placebo: Group-1 = priming (7Days) pre-injury, Group-2 = priming (3D) pre-injury, Group-3 = immediate (0D) day-of-injury, Group-4 = delayed application (14D) post-injury. Excisional skin-biopsies in upper-arms were evaluated weekly with multiple quantitative devices over 8-weeks. Histological, immunohistochemical, mRNA sequencing and QRT-PCR studies were performed on tissue-biopsies. EGCG reduced mast cells at weeks-4 and 8 by gene and protein analyses (p < 0.01). Group 1 was superior to other groups (p < 0.01) in both clinical (blood flow) and laboratory parameters (elastin and immune marker expression). Additionally, there was down-regulation of angiogenic-markers by mRNA-sequencing and of CD31 and VEGF-A at weeks-4 and 8 (p < 0.01) by immunohistochemistry and at week-4 (p < 0.05) by QRT-PCR. EGCG increased antioxidant levels (HO-1) at week-4 (p < 0.01) plus elastin at week-8 (p < 0.01). In conclusion, pre-emptive priming of skin pre-injury has significant beneficial effects on surgically induced skin scarring shown by reducing mast cells, blood flow and angiogenesis plus increasing elastin content. This clinical trial was registered with ISRCTN (ISRCTN70155584).

Pre-Emptive Priming of Human Skin Improves Cutaneous Scarring and Is Superior to Immediate and Delayed Topical Anti-Scarring Treatment Post-Wounding: A Double-Blind Randomised Placebo-Controlled Clinical Trial

The concept of pre-emptive priming of skin pre-surgery offers a novel approach in optimizing cutaneous scarring outcome. We previously showed an anti-scarring topical (epigallocatechin-3-gallate (EGCG)) is effective in improving skin scarring when applied post-surgery. The objective was to deliver an active compound at the optimal time in order to maximize its impact and improve cutaneous scarring. Therefore, pre-emptive application of anti-scarring topical pre-surgery compared with post-surgery can potentially be superior on scarring outcome. This double-blinded randomized placebo-controlled trial compares the effects of pre-emptive priming of skin with an anti-scarring topical pre-surgery versus post-surgery. Healthy volunteers (n = 40) were split into 4-groups; each undergoing different modes of application versus placebo: Group-1 = priming (7Days) pre-injury, Group-2 = priming (3D) pre-injury, Group-3 = immediate (0D) day-of-injury, Group-4 = delayed application (14D) post-injury. Excisional skin-biopsies in upper-arms were evaluated weekly with multiple quantitative devices over 8-weeks. Histological, immunohistochemical, mRNA sequencing and QRT-PCR studies were performed on tissue-biopsies. EGCG reduced mast cells at weeks-4 and 8 by gene and protein analyses (p < 0.01). Group 1 was superior to other groups (p < 0.01) in both clinical (blood flow) and laboratory parameters (elastin and immune marker expression). Additionally, there was down-regulation of angiogenic-markers by mRNA-sequencing and of CD31 and VEGF-A at weeks-4 and 8 (p < 0.01) by immunohistochemistry and at week-4 (p < 0.05) by QRT-PCR. EGCG increased antioxidant levels (HO-1) at week-4 (p < 0.01) plus elastin at week-8 (p < 0.01). In conclusion, pre-emptive priming of skin pre-injury has significant beneficial effects on surgically induced skin scarring shown by reducing mast cells, blood flow and angiogenesis plus increasing elastin content. This clinical trial was registered with ISRCTN (ISRCTN70155584).

Assessment of Transdermal Delivery of Topical Compounds in Skin Scarring Using a Novel Combined Approach of Raman Spectroscopy and High-Performance Liquid Chromatography

Objective: The goal of any topical formulation is efficient transdermal delivery of its active components. However, delivery of compounds can be problematic with penetration through tough layers of fibrotic dermal scar tissue. Approach: We propose a new approach combining high-performance liquid chromatography (HPLC) and Raman spectroscopy (RS) using a topical of unknown composition against a well-known antiscar topical (as control). Results: Positive detection of compounds within the treatment topical using both techniques was validated with mass spectrometry. RS detected conformational structural changes; the 1,655/1,446 cm^-1 ratio estimating collagen content significantly decreased (p < 0.05) over weeks 4, 12, and 16 compared with day 0. The amide I band, known to represent collagen and protein in skin, shifted from 1,667 to 1,656 cm^-1, which may represent a change from β-sheets in elastin to α-helices in collagen. Confirmatory elastin immunohistochemistry decreased compared with day 0, conversely the collagen I/III ratio increased in the same samples by week 12 (p < 0.05, and p < 0.0001, respectively), in keeping with normal scar formation. Optical coherence tomography attenuation coefficient representing collagen deposition was significantly decreased at week 4 compared with day 0 and increased at week 16 (p < 0.05). Innovation: This study provides a platform for further research on the simultaneous evaluation of the effects of compounds in cutaneous scarring by RS and HPLC, and identifies a role for RS in the therapeutic evaluation and theranostic management of skin scarring. Conclusions: RS can provide noninvasive information on the effects of topicals on scar pathogenesis and structural composition, validated by other analytical techniques.

A Review of the Evidence for and against a Role for Mast Cells in Cutaneous Scarring and Fibrosis

Scars are generated in mature skin as a result of the normal repair process, but the replacement of normal tissue with scar tissue can lead to biomechanical and functional deficiencies in the skin as well as psychological and social issues for patients that negatively affect quality of life. Abnormal scars, such as hypertrophic scars and keloids, and cutaneous fibrosis that develops in diseases such as systemic sclerosis and graft-versus-host disease can be even more challenging for patients. There is a large body of literature suggesting that inflammation promotes the deposition of scar tissue by fibroblasts. Mast cells represent one inflammatory cell type in particular that has been implicated in skin scarring and fibrosis. Most published studies in this area support a pro-fibrotic role for mast cells in the skin, as many mast cell-derived mediators stimulate fibroblast activity and studies generally indicate higher numbers of mast cells and/or mast cell activation in scars and fibrotic skin. However, some studies in mast cell-deficient mice have suggested that these cells may not play a critical role in cutaneous scarring/fibrosis. Here, we will review the data for and against mast cells as key regulators of skin fibrosis and discuss scientific gaps in the field.

Inflammation as an orchestrator of cutaneous scar formation: a review of the literature

Inflammation is a key phase in the cutaneous wound repair process. The activation of inflammatory cells is critical for preventing infection in contaminated wounds and results in the release of an array of mediators, some of which stimulate the activity of keratinocytes, endothelial cells, and fibroblasts to aid in the repair process. However, there is an abundance of data suggesting that the strength of the inflammatory response early in the healing process correlates directly with the amount of scar tissue that will eventually form. This review will summarize the literature related to inflammation and cutaneous scar formation, highlight recent discoveries, and discuss potential treatment modalities that target inflammation to minimize scarring.

Part 1. Evaluation of Epigallocatechin Gallate or Tannic Acid Formulations of Hydrophobic Drugs for Enhanced Dermal and Bladder Uptake or for Local Anesthesia Effects

Epigallocatechin gallate (EGCG) and tannic acid (TA) are known to increase the aqueous solubility and cellular uptake of the hydrophobic drugs docetaxel, paclitaxel, amphotericin B, and curcumin. In this study the practical application of gallate-based solubilization phenomena for the uptake of these drugs into dermal and bladder tissue and of lidocaine for wound healing application was studied. The penetration of all these drugs into pig skin or docetaxel into pig bladder using EGCG or TA formulations was measured. Overall, EGCG and TA particulate or propylene glycol paste formulations of drugs allowed for greatly increased levels of drug uptake into skin as compared to control formulations. EGCG/propylene glycol pastes allowed for rapid lidocaine uptake into skin. EGCG and TA formulations of docetaxel allowed for approximately 10 fold increases in bladder tissue uptake of docetaxel over tween based solutions. Morphologically, both EGCG and TA caused a mild, dose dependent exfoliation of the bladder wall. Both EGCG and TA formed injectable viscous pastes with propylene glycol which solidified in water and degraded and released lidocaine over 2-35 days. These data support the use of EGCG and TA based formulations of certain drugs for improved dermal, bladder and wound applications.

Mast Cells in Skin Scarring: A Review of Animal and Human Research

Mast cells (MCs) are an important immune cell type in the skin and play an active role during wound healing. MCs produce mediators that can enhance acute inflammation, stimulate re-epithelialisation as well as angiogenesis, and promote skin scarring. There is also a link between MCs and abnormal pathological cutaneous scarring, with increased numbers of MCs found in hypertrophic scars and keloid disease. However, there has been conflicting data regarding the specific role of MCs in scar formation in both animal and human studies. Whilst animal studies have proved to be valuable in studying the MC phenomenon in wound healing, the appropriate translation of these findings to cutaneous wound healing and scar formation in human subjects remains crucial to elucidate the role of these cells and target treatment effectively. Therefore, this perspective paper will focus on evaluation of the current evidence for the role of MCs in skin scarring in both animals and humans in order to identify common themes and future areas for translational research.

Dietary Flavonoids in p53-Mediated Immune Dysfunctions Linking to Cancer Prevention

The p53 protein plays a central role in mediating immune functioning and determines the fate of the cells. Its role as a tumor suppressor, and in transcriptional regulation and cytokine activity under stress conditions, is well defined. The wild type (WT) p53 functions as a guardian for the genome, while the mutant p53 has oncogenic roles. One of the ways that p53 combats carcinogenesis is by reducing inflammation. WT p53 functions as an anti-inflammatory molecule via cross-talk activity with multiple immunological pathways, such as the major histocompatibility complex I (MHCI) associated pathway, toll-like receptors (TLRs), and immune checkpoints. Due to the multifarious roles of p53 in cancer, it is a potent target for cancer immunotherapy. Plant flavonoids have been gaining recognition over the last two decades to use as a potential therapeutic regimen in ameliorating diseases. Recent studies have shown the ability of flavonoids to suppress chronic inflammation, specifically by modulating p53 responses. Further, the anti-oxidant Keap1/Nrf2/ARE pathway could play a crucial role in mitigating oxidative stress, leading to a reduction of chronic inflammation linked to the prevention of cancer. This review aims to discuss the pharmacological properties of plant flavonoids in response to various oxidative stresses and immune dysfunctions and analyzes the cross-talk between flavonoid-rich dietary intake for potential disease prevention.

Extracellular vesicle-enclosed miR-486-5p mediates wound healing with adipose-derived stem cells by promoting angiogenesis

Adipose‐derived stem cells (ASC) are said to have a pivotal role in wound healing. Specifically, ASC‐secreted extracellular vesicles (EV) carry diverse cargos such as microRNAs (miRNAs) to participate in the ASC‐based therapies. Considering its effects, we aimed to investigate the role of ASC‐EVs in the cutaneous wound healing accompanied with the study on the specific cargo‐medicated effects on wound healing. Two full‐thickness excisional skin wounds were created on mouse dorsum, and wound healing was recorded at the indicated time points followed by histological analysis and immunofluorescence staining for CD31 and α‐SMA. Human skin fibroblasts (HSFs) and human microvascular endothelial cells (HMECs) were co‐cultured with EVs isolated from ASC (ASC‐EVs), respectively, followed by the evaluation of their viability and mobility using CCK‐8, scratch test and transwell migration assays. Matrigel‐based angiogenesis assays were performed to evaluate vessel‐like tube formation by HMECs in vitro. ASC‐EVs accelerated the healing of full‐thickness skin wounds, increased re‐epithelialization and reduced scar thickness whilst enhanced collagen synthesis and angiogenesis in murine models. However, miR‐486‐5p antagomir abrogated the ASC‐EVs‐induced effects. Intriguingly, miR‐486‐5p was found to be highly enriched in ASC‐EVs, exhibiting an increase in viability and mobility of HSFs and HMECs and enhanced the angiogenic activities of HMECs. Notably, we also demonstrated that ASC‐EVs‐secreted miR‐486‐5p achieved the aforesaid effects through its target gene Sp5. Hence, our results suggest that miR‐486‐5p released by ASC‐EVs could be a critical mediator to develop an ASC‐based therapeutic strategy for wound healing.

Great green tea ingredient? A narrative literature review on epigallocatechin gallate and its biophysical properties for topical use in dermatology

The purpose of this review is to examine epigallocatechin-3-gallate (EGCG) regarding its stability in different conditions (pH-value, concentration, temperature), its interactions with common cosmetic ingredients, and its application in the dermatological field. The literature research considered published journal articles (clinical trials and scientific reviews). Studies were identified by searching electronic databases (MEDLINE and PubMed) and reference lists of respective articles. Higher concentrations of EGCG were reported to correlate with better stability and the same can be said for low temperatures and pH values. The interaction between EGCG and hyaluronic acid strengthens its antioxidant activities. Titanium dioxide coated with EGCG proved a suitable ingredient in sunscreens. The polyphenol possesses antioxidant properties, which proved effective in the prevention of UV-induced skin damage and to alleviate the symptoms of Imiquimod-induced psoriasis. The three endpoints of this review not only showed interesting results but also highlighted some limitations of EGCG. Studies show that the molecule is unstable, which may hinder its dermatological and cosmetic applications. The reported interactions with cosmetic ingredients were limited. As the health aspects of EGCG are well-reported, ECGC has become a focus of interest for health professionals trying to treat common dermatological diseases.