The evidence for natural therapeutics as potential anti-scarring agents in burn-related scarring

How Thymoquinone from Nigella sativa Accelerates Wound Healing through Multiple Mechanisms and Targets

Wound healing is a multifaceted process necessitating the collaboration of numerous elements to mend damaged tissue. Plant and animal-derived natural compounds have been utilized for wound treatment over the centuries, with many scientific investigations examining these compounds. Those with antioxidant, anti-inflammatory, and antibacterial properties are particularly noteworthy, as they target various wound-healing stages to expedite recovery. Thymoquinone, derived from Nigella sativa (N. sativa)-a medicinal herb with a long history of use in traditional medicine systems such as Unani, Ayurveda, Chinese, and Greco-Arabic and Islamic medicine-has demonstrated a range of therapeutic properties. Thymoquinone exhibits antimicrobial, anti-inflammatory, and antineoplastic activities, positioning it as a potential remedy for skin pathologies. This review examines recent research on how thymoquinone accelerates wound healing and the mechanisms behind its effectiveness. We carried out a comprehensive review of literature and electronic databases, including Google Scholar, PubMed, Science Direct, and MedlinePlus. Our aim was to gather relevant papers published between 2015 and August 2023. The main criteria for inclusion were that the articles had to be peer reviewed, original, written in English, and discuss the wound-healing parameters of thymoquinone in wound repair. Our review focused on the effects of thymoquinone on the cellular and molecular mechanisms involved in wound healing. We also examined the role of cytokines, signal transduction cascades, and clinical trials. We found sufficient evidence to support the effectiveness of thymoquinone in promoting wound healing. However, there is no consensus on the most effective concentrations of these substances. It is therefore essential to determine the optimal treatment doses and the best route of administration. Further research is also needed to investigate potential side effects and the performance of thymoquinone in clinical trials.

From In Silico Simulation between TGF-β Receptors and Quercetin to Clinical Insight of a Medical Device Containing Allium cepa: Its Efficacy and Tolerability on Post-Surgical Scars

(1) Objective: Keloid and hypertrophic scars are a challenge in clinical management, causing functional and psychological discomfort. These pathological scars are caused by a proliferation of dermal tissue following skin injury. The TGF-β/Smad signal pathway in the fibroblasts and myofibroblasts is involved in the scarring process of skin fibrosis. Today, multiple therapeutic strategies that target the TGF-β/Smad signal pathway are evaluated to attenuate aberrant skin scars that are sometimes difficult to manage. We performed a head-to-head, randomized controlled trial evaluating the appearance of the post-surgical scars of 64 subjects after two times daily topical application to compare the effect of a class I pullulan-based medical device containing Allium cepa extract 5% and hyaluronic acid 5% gel versus a class I medical device silicone gel on new post-surgical wounds. (2) Methods: Objective scar assessment using the Vancouver Scar Scale (VSS), POSAS, and other scales were performed after 4, 8, and 12 weeks of treatment and statistical analyses were performed. The trial was registered in clinicalTrials.gov ( NCT05412745). In parallel, molecular docking simulations have been performed to investigate the role of Allium cepa in TGF-β/Smad signal pathway. (3) Results: We showed that VSS, POSAS scale, itching, and redness reduced significantly at week 4 and 8 in the subjects using devices containing Allium cepa and HA. No statistically significant differences in evaluated scores were noted at 12 weeks of treatment. Safety was also evaluated by gathering adverse events related to the application of the gel. Subject compliance and safety with the assigned gel were similar between the two study groups. Molecular docking simulations have shown how Allium cepa could inhibit fibroblasts proliferation and contraction via TGF-β/Smad signal pathway. (4) Conclusions: The topical application of a pullulan-based medical device containing Allium cepa and HA showed a clear reduction in the local inflammation, which might lead to a reduced probability of developing hypertrophic scars or keloids.

Kampo herbal ointments for skin wound healing

The management of skin wound healing problems is a public health issue in which traditional herbal medicines could play a determining role. Kampo medicine, with three traditionally used ointments, provides interesting solutions for these dermatological issues. These ointments named Shiunkō, Chuōkō, and Shinsen taitsukō all have in common a lipophilic base of sesame oil and beeswax from which herbal crude drugs are extracted according to several possible manufacturing protocols. This review article brings together existing data on metabolites involved in the complex wound healing process. Among them are representatives of the botanical genera Angelica, Lithospermum, Curcuma, Phellodendron, Paeonia, Rheum, Rehmannia, Scrophularia, or Cinnamomum. Kampo provides numerous metabolites of interest, whose content in crude drugs is very sensitive to different biotic and abiotic factors and to the different extraction protocols used for these ointments. If Kampo medicine is known for its singular standardization, ointments are not well known, and research on these lipophilic formulas has not been developed due to the analytical difficulties encountered in biological and metabolomic analysis. Further research considering the complexities of these unique herbal ointments could contribute to a rationalization of Kampo's therapeutic uses for wound healing.

Wound Healing Properties of Natural Products: Mechanisms of Action

A wound is the loss of the normal integrity, structure, and functions of the skin due to a physical, chemical, or mechanical agent. Wound repair consists of an orderly and complex process divided into four phases: coagulation, inflammation, proliferation, and remodeling. The potential of natural products in the treatment of wounds has been reported in numerous studies, emphasizing those with antioxidant, anti-inflammatory, and antimicrobial properties, e.g., alkaloids, saponins, terpenes, essential oils, and polyphenols from different plant sources, since these compounds can interact in the various stages of the wound healing process. This review addresses the most current in vitro and in vivo studies on the wound healing potential of natural products, as well as the main mechanisms involved in this activity. We observed sufficient evidence of the activity of these compounds in the treatment of wounds; however, we also found that there is no consensus on the effective concentrations in which the natural products exert this activity. For this reason, it is important to work on establishing optimal treatment doses, as well as an appropriate route of administration. In addition, more research should be carried out to discover the possible side effects and the behavior of natural products in clinical trials.

In Vitro and In Vivo Biocompatible and Controlled Resveratrol Release Performances of HEMA/Alginate and HEMA/Gelatin IPN Hydrogel Scaffolds

Scaffold hydrogel biomaterials designed to have advantageous biofunctional properties, which can be applied for controlled bioactive agent release, represent an important concept in biomedical tissue engineering. Our goal was to create scaffolding materials that mimic living tissue for biomedical utilization. In this study, two novel series of interpenetrating hydrogel networks (IPNs) based on 2-hydroxyethyl methacrylate/gelatin and 2-hydroxyethyl methacrylate/alginate were crosslinked using N-ethyl-N'-(3-dimethyl aminopropyl)carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS). Characterization included examining the effects of crosslinker type and concentration on structure, morphological and mechanical properties, in vitro swelling, hydrophilicity as well as on the in vitro cell viability (fibroblast cells) and in vivo (Caenorhabditis elegans) interactions of novel biomaterials. The engineered IPN hydrogel scaffolds show an interconnected pore morphology and porosity range of 62.36 to 85.20%, favorable in vitro swelling capacity, full hydrophilicity, and Young's modulus values in the range of 1.40 to 7.50 MPa. In vitro assay on healthy human fibroblast (MRC5 cells) by MTT test and in vivo (Caenorhabditis elegans) survival assays show the advantageous biocompatible properties of novel IPN hydrogel scaffolds. Furthermore, in vitro controlled release study of the therapeutic agent resveratrol showed that these novel scaffolding systems are suitable controlled release platforms. The results revealed that the use of EDC and the combination of EDC/NHS crosslinkers can be applied to prepare and tune the properties of the IPN 2-hydroxyethyl methacrylate/alginate and 2-hydroxyethyl methacrylate/gelatin hydrogel scaffolds series, which have shown great potential for biomedical engineering applications.

Prospective, Randomized, Double-Blind, Placebo-Controlled Study on Efficacy of Copaiba Oil in Silicone-Based Gel to Reduce Scar Formation

Introduction

Scars are the end result of a biologic and natural process of wound repair after injury, surgery, acne, illness, burns, and infection. When skin is damaged, a fast and coordinated body response is triggered by four highly integrated and overlapping phases including homeostasis, inflammation, proliferation, and tissue remodeling. Healing of a skin wound may result in an abnormal scar if the balance among these four phases is lost during the healing process. Various topical treatments have been used for their ability to reduce unsightly scar formation. Recently, studies have shown improvement in scar appearance after treating with silicone gels containing natural herbal ingredients. The aim of this study is to evaluate the efficacy of a novel silicone-based gel containing copaiba oil (Copaderm) for prevention and/or appearance reduction of different types of abnormal scars.

Methods

This study was designed as a prospective, randomized, double-blind, placebo-controlled trial involving 42 patients with abnormal scars, divided into two groups. Each group received either a topical scar formulation consisting of copaiba oil in silicone gel or a placebo gel twice a day for 84 days. Assessments of the scars were performed at 0, 28, and 84 days following the onset of topical application using three methods: a clinical assessment using the Manchester Scar Scale, a photographic assessment to establish before and after treatment improvements, and at the end of the study period, patients completed a final satisfaction questionnaire.

Results

Of the original 42 patients, 32 completed the evaluation. There was a significant difference with respect to the overall score of the Manchester Scar Scale between the two groups from baseline to 84 days (P < 0.05). All patients with copaiba oil in silicone gel achieved improvement of their scars, based on overall score at 84 days. A visible scar reduction was observed with photographic assessment. Eighty-nine percent of subjects (n = 16) with copaiba oil in silicone gel rated as being satisfied or very satisfied after 84 days of treatment.

Conclusion

Our findings support the hypothesis that copaiba oil in silicone-derivative gel was able obtain significant improvement in color, contour, distortion, and texture for different types of scar through the Manchester Scar Scale analysis. These findings contribute to reducing abnormal scar formation during the healing process.

Marine Polysaccharides for Wound Dressings Application: An Overview

Wound dressings have become a crucial treatment for wound healing due to their convenience, low cost, and prolonged wound management. As cutting-edge biomaterials, marine polysaccharides are divided from most marine organisms. It possesses various bioactivities, which allowing them to be processed into various forms of wound dressings. Therefore, a comprehensive understanding of the application of marine polysaccharides in wound dressings is particularly important for the studies of wound therapy. In this review, we first introduce the wound healing process and describe the characteristics of modern commonly used dressings. Then, the properties of various marine polysaccharides and their application in wound dressing development are outlined. Finally, strategies for developing and enhancing marine polysaccharide wound dressings are described, and an outlook of these dressings is given. The diverse bioactivities of marine polysaccharides including antibacterial, anti-inflammatory, haemostatic properties, etc., providing excellent wound management and accelerate wound healing. Meanwhile, these biomaterials have higher biocompatibility and biodegradability compared to synthetic ones. On the other hand, marine polysaccharides can be combined with copolymers and active substances to prepare various forms of dressings. Among them, emerging types of dressings such as nanofibers, smart hydrogels and injectable hydrogels are at the research frontier of their development. Therefore, marine polysaccharides are essential materials in wound dressings fabrication and have a promising future.

Effectiveness and Tolerability of a Patch Containing Onion Extract and Allantoin for Cesarean Section Scars

Background

The prevention or early treatment of pathological scars is the most appropriate therapeutic approach. Gels and patches containing onion extract and allantoin are safe and effective in patients with scars of various origins and severity. However, no controlled studies have evaluated the effects of the patch formulation in women after Cesarean delivery. This study aimed to investigate the effects of a patch containing Allium cepa and allantoin on Cesarean section (C-section) scars.

Methods

This is an observational study. Women were consecutively recruited at the University Hospital of Salerno and subdivided into two groups considering the number of C-section. Group A included subjects without and group B with a history of C-section. Scars assessment was made using digital photographs and the Patient and Observer Scar Assessment Scale (POSAS). After 4 weeks, the C-section of the women who had applied a patch containing Allium cepa and allantoin and those of women who had not used any products (controls) were re-evaluated as at baseline. The Observers independently performed the scars assessment at baseline and after 4 weeks. Data are expressed as the difference of the POSAS scores after 4 weeks minus the POSAS scores at baseline. The statistical significance was established at a p value <0.05.

Results

Ninety-three subjects completed the study (47 in group A and 46 in group B). Women who had used a patch showed an improvement in total score by observer scale when compared with controls (p = 0.013). By the patient scale, no significant changes from baseline were found in group A and group B. Group B with patch showed changes in scars’ pigmentation (p = 0.015), relief (p = 0.039), and pliability (p = 0.046) in comparison of controls. Digital photographs confirmed such improvements in women who had already undergone previous C-section, while no significant changes from baseline were found in women without a history of C-section.

Conclusions

Intense treatment of just 4 weeks with a patch containing Alium Cepa extract and allantoin was able to improve pigmentation, relief, and pliability of C-section scars in women with a history of C-section.

Clinical trial registration

ClinicalTrials.gov, identifier NCT04046783.

Resveratrol inhibits hypertrophic scars formation by activating autophagy via the miR-4654/Rheb axis

Hypertrophic scars (HSs) are a type of pathological scar which are induced by surgery, burn injuries or trauma during the healing process. Due to the high recurrence rates and strong invasive properties, HSs have become a major clinical issue. Resveratrol has been identified as a potential agent to suppress scar formation; however, the underlying mechanism of action remains unclear. Therefore, the present study aimed to investigate the effect of resveratrol on HS-derived fibroblasts (HSFBs) in vitro. MTT assay was performed to evaluate cell viability following the resveratrol treatment. Western blot and RT-qPCR analysis was used to identify the expression levels and the relationship among autophagic markers, miR-4654 and resveratrol treatment. Finally, GFP-LC3 stable HSFBs cells were generated to further assess the effect of resveratrol. The results revealed that resveratrol significantly induced cell death in a dose-dependent manner and induced autophagy by downregulating the expression levels of Rheb in HSFBs. Notably, microRNA-4654 (miR-4654) was significantly decreased in the HSFBs and re-upregulated by resveratrol treatment dose-dependently. Through the bioinformatic analysis and luciferase assay, miR-4654 was identified to directly target Rheb. Transfection studies showed that miR-4654 negative correlated with Rheb expression, suggesting that the autophagic process may be altered by the miR-4654/Rheb axis under the control of resveratrol. In conclusion, the results of the present study suggested that resveratrol may promote autophagy by upregulating miR-4654, which in turn may suppress Rheb expression via directly binding to the 3′-untranslated region of Rheb. These findings provided a novel insight into the development of potential therapeutic targets for HSs.

Hepatocyte Growth Factor Secreted from Human Adipose-Derived Stem Cells Inhibits Fibrosis in Hypertrophic Scar Fibroblasts

AIMS

To study the effect of Adipose-derived stem cells (ADSCs) on fibrosis of hypertrophic scar-derived fibroblasts (HSFs) and its concrete mechanism.

BACKGROUND

ADSCs have been reported to reduce collagen production and fibroblast proliferation in co-culture experiments. Conditioned medium from adipose-derived stem cells (ADSCs-CM) has successfully inhibited fibrosis by decreasing the expression of collagen type І (Col1) and α-smooth muscle actin (α-SMA) in rabbit ear scar models. Hepatocyte growth factor (HGF), the primary growth factor in ADSCs-CM, has been shown to reverse fibrosis in various fibrotic diseases.

OBJECTIVE

To test the hypothesis that ADSCs inhibit fibrosis of HSFs through the secretion of HGF.

METHODS

HSFs were treated with DMEM containing 0%, 10%, 50% and 100% concentration of ADSCs-CM. The effect of ADSCs-CM on the viability was determined by cell viability assay, and the collagen production in HSFs was examined by Sirius red staining. Expression and secretion of fibrosis and degradation proteins were detected separately. After measuring the concentration of HGF in ADSCs-CM, the same number of HSFs were treated with 50% ADSCs-CM or HGF. HGF activity in ADSCs-CM was neutralized with a goat anti-human HGF antibody.

RESULTS

The results demonstrated that ADSCs-CM dose-dependently decreased cell viability, expression of fibrosis molecules, and tissue inhibitor of metalloproteinases-1 (TIMP-1), and significantly increased matrix metalloproteinase-1 (MMP-1) expression in HSFs. Collagen production and the ratio of collagen type І and type III (Col1/Col3) were also suppressed by ADSCs-CM in a dose-dependent manner. When HSFs were cultured with either 50% ADSCs-CM or HGF (1 ng/ml), a similar trend was observed in gene expression and protein secretion. Adding an HGF antibody to both groups returned protein expression and secretion to basal levels but did not significantly affect the fibrosis factors in the control group.

CONCLUSION

Our findings revealed that adipose-derived stem cell-secreted HGF effectively inhibits fibrosis-related factors and regulates extracellular matrix (ECM) remodeling in hypertrophic scar fibroblasts.

Resveratrol inhibits proliferation and promotes apoptosis of keloid fibroblasts by targeting HIF-1α

A keloid is characterized by red, tickling, hard, and irregular raised tissues, and it tends to outgrow its origin. It frequently occurs in young adults and appears to be refractory to prevailing therapies. Resveratrol is a new drug that has anti-proliferative effect. In this study, keloid-derived fibroblasts were cultured under hypoxia environment and was treated by resveratrol. CCK-8 assay and Annexin V-FITC were used to evaluate cell activity and apoptosis level. Western blot and RT-qPCR were also used to assess the expression of HIF-α, Collagen I and Collagen III. Besides, siRNA was also used to explore the mechanisms of resveratrol's effect. In this study, hypoxia promotes proliferation and inhibits apoptosis of keloid fibroblasts. These findings highlight the potential obstacle in treating keloids. Furthermore, we demonstrated that resveratrol could reverse the effect of hypoxia on keloids through down-regulation of HIF-1α. Moreover, collagen synthesis in keloid fibroblasts was also inhibited by resveratrol, which corresponded with HIF-1α suppression. These results provide evidence for resveratrol's treatment effect against keloids through inhibiting cell proliferation and promoting cell apoptosis, while, HIF-1α may play the key role in this process.

Resveratrol-loaded peptide-hydrogels inhibit scar formation in wound healing through suppressing inflammation

Scar formation seriously affects the repair of damaged skin especially in adults and the excessive inflammation has been considered as the reason. The self-assembled peptide-hydrogels are ideal biomaterials for skin wound healing due to their similar nanostructure to natural extracellular matrix, hydration environment and serving as drug delivery systems. In our study, resveratrol, a polyphenol compound with anti-inflammatory effect, is loaded into peptide-hydrogel (Fmoc-FFGGRGD) to form a wound dressing (Pep/RES). Resveratrol is slowly released from the hydrogel in situ, and the release amount is controlled by the loading amount. The in vitro cell experiments demonstrate that the Pep/RES has no cytotoxicity and can inhibit the production of pro-inflammatory cytokines of macrophages. The Pep/RES hydrogels are used as wound dressings in rat skin damage model. The results suggest that the Pep/RES dressing can accelerate wound healing rate, exhibit well-organized collagen deposition, reduce inflammation and eventually prevent scar formation. The Pep/RES hydrogels supply a potential product to develop new skin wound dressings for the therapy of skin damage.

Novel pharmacotherapy for burn wounds: what are the advancements

INTRODUCTION

The prognosis for severe burns has improved significantly over the past 50 years. Meanwhile, burns have become an affliction mainly affecting the less well-developed regions of the world. Early excision and skin grafting has led to major improvements in therapeutic outcomes.

AREAS COVERED

The purpose of this article is to survey the use of pharmacotherapy to treat different pathophysiological complications of burn injury. The author, herein, discusses the use of drug treatments for a number of systemic metabolic disturbances including hyperglycemia, elevated catabolism, and gluconeogenesis.

EXPERT OPINION

Advancements in personalized and molecular medicine will make an impact on burn therapy. Similarities between severe burns and other critically ill patients will lead to cross-fertilization between different medical specialties. Furthermore, advances in stem cells and tissue regeneration will lead to improved healing and less lifelong disability. Indeed, research in new drug therapy for burns is actively progressing for many different complications.

A Randomized, Placebo-Controlled, Double-Blind, Prospective Clinical Trial of Botulinum Toxin Type A in Prevention of Hypertrophic Scar Development in Median Sternotomy Wound

BACKGROUND

Linear hypertrophic scar is a common surgical problem that can be difficult to manage, especially for the median sternotomy scar. Botulinum toxin type A (BTA) is widely used in cosmetic surgery and has been shown to improve scar quality recently. The aim of this study was to evaluate the efficacy of BTA injected in the early postoperative of median sternotomy on preventing scar formation.

METHODS

In this prospective randomized controlled trial, 19 consecutive patients who underwent median sternotomy were enrolled. The median sternotomy wound in each patient was divided into the upper half and the lower half. Both halves of the wound were randomized to receive the treatment with either BTA or normal saline. At 6-month follow-up, scars were assessed using the Vancouver Scar Scale, scar widths were measured, and patients were asked to evaluate their overall satisfaction.

RESULTS

Seventeen patients with median sternotomy wounds completed the entire study. At 6-month follow-up, the mean Vancouver Scar Scale score for the BTA-treated group was 3.44 ± 1.68 and for the normal saline control group was 6.29 ± 2.39, and there was a statistically significant difference between the two groups (P < 0.05). There were also significant improvements in scar width and patient satisfaction for the BTA-treated halves of the wounds (P < 0.05).

CONCLUSIONS

The study demonstrates that early postoperative BTA injection can decrease scar formation and reduce scar width in median sternotomy wounds, and the overall appearance is more satisfactory.

LEVEL OF EVIDENCE I

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Bioprinting of skin constructs for wound healing

Extensive burns and full-thickness skin wounds are difficult to repair. Autologous split-thickness skin graft (ASSG) is still used as the gold standard in the clinic. However, the shortage of donor skin tissues is a serious problem. A potential solution to this problem is to fabricate skin constructs using biomaterial scaffolds with or without cells. Bioprinting is being applied to address the need for skin tissues suitable for transplantation, and can lead to the development of skin equivalents for wound healing therapy. Here, we summarize strategies of bioprinting and review current advances of bioprinting of skin constructs. There will be challenges on the way of 3D bioprinting for skin regeneration, but we still believe bioprinting will be potential skills for wounds healing in the foreseeable future.

From Inflammation to Current and Alternative Therapies Involved in Wound Healing

Wound healing is a complex event that develops in three overlapping phases: inflammatory, proliferative, and remodeling. These phases are distinct in function and histological characteristics. However, they depend on the interaction of cytokines, growth factors, chemokines, and chemical mediators from cells to perform regulatory events. In this article, we will review the pathway in the skin healing cascade, relating the major chemical inflammatory mediators, cellular and molecular, as well as demonstrating the local and systemic factors that interfere in healing and disorders associated with tissue repair deficiency. Finally, we will discuss the current therapeutic interventions in the wounds treatment, and the alternative therapies used as promising results in the development of new products with healing potential.