From a traditional medicinal plant to a rational drug: understanding the clinically proven wound healing efficacy of birch bark extract

Tissue engineered multifunctional chitosan-modified polypropylene hernia mesh loaded with bioactive phyto-extracts

Surface modified tissue engineered polypropylene / PP hernia meshes were fabricated by incorporating Bacterial cellulose / BC and chitosan / CS and phytochemical extracts. Under current practice, hernia and other traumatic injuries to the abdominal organs are clinically treated with surgical meshes. Often the foreign body reaction and infections result in relapse in patients which dictates additional reparative surgical procedures and pain. To improve the outcome of clinical restorative procedures new biomaterials with improved characteristics are required. The functionalized meshes were physically and chemically characterized using SEM, mechanical testing, FTIR and XRD. The antimicrobial activity was qualitatively and quantitatively tested using E. coli and S. aureus strains of bacteria. In vitro biocompatibility and wound healing effect of the modified meshes were performed using NIH3T3 fibroblast cell lines. Furthermore, tissue engineering potential of the meshes was evaluated using confocal fluorescent microscopy. In vivo implantation of the meshes was performed in male wistar rats for 21 days. Therefore, PP meshes with sustained drug delivery system augmented with anti-inflammatory and anti-microbial characteristics were developed. The coatings hereby not only increased the tensile strength of meshes but also prevented the modified meshes from causing infection. Current study resulted in CS-BC bioactive PP meshes loaded with phytochemicals which showed anti-inflammatory, antibacterial and wound healing potential. These meshes can be valuable to lessen the post-surgical complications of implanted PP mesh and thus reduce rejection and recurrence.

Beyond the Surface: A Narrative Review Examining the Systemic Impacts of Recessive Dystrophic Epidermolysis Bullosa

Recessive dystrophic epidermolysis bullosa (RDEB) is a rare genetic disease resulting from inadequate type VII collagen (C7). Although recurrent skin blisters and wounds are the most apparent disease features, the impact of C7 loss is not confined to the skin and mucous membranes. RDEB is a systemic disease marred by chronic inflammation, fibrotic changes, pain, itch, and anemia, significantly impacting QOL and survival. In this narrative review, we summarize these systemic features of RDEB and promising research avenues to address them.

Obtaining New Biocompatible Composite Materials with Antibacterial Properties Based on Diatomite and Biologically Active Compounds

This study aimed to create new composite materials based on diatomite-a non-organic porous compound-through its surface modification with bioactive organic compounds, both synthetic and natural. Chloramphenicol, tetrahydroxymethylglycoluril and betulin were used as modifying substances. Composite materials were obtained by covering the diatomite surface with bioactive substance compounds as a solution and material dispersion in it. The materials were characterized by IR spectroscopy, SEM and X-ray photoelectron spectroscopy. For the biocomposites, the hemolytic effect, plasma proteins' adsorption on the surface and the antibacterial activity of the obtained materials were studied. Results show that the obtained materials are promising for medicine and agriculture.

Targeted inhibition of colorectal cancer proliferation: The dual-modulatory role of 2,4-DTBP on anti-apoptotic Bcl-2 and Survivin proteins

The anti-apoptotic proteins, Bcl-2 and Survivin, are consistently overexpressed in numerous human malignancies, notably in colorectal cancer. 2,4-Di-tert-butylphenol (2,4-DTBP) is a naturally occurring phenolic compound known for its diverse biological activities, including anti-cancer properties. The mechanism behind 2,4-DTBP-induced inhibition of cell proliferation and apoptosis in human colorectal cancer cells, specifically regarding Bcl-2 and Survivin, remains to be elucidated. In this study, we employed both in silico and in vitro methodologies to underpin this interaction at the molecular level. Molecular docking demonstrated a substantial binding affinity of 2,4-DTBP towards Bcl-2 (ΔG = -9.8 kcal/mol) and Survivin (ΔG = -5.6 kcal/mol), suggesting a potential inhibitory effect. Further, molecular dynamic simulations complemented by MM-GBSA calculations confirmed the significant binding of 2,4-DTBP with Bcl-2 (dGbind = -54.85 ± 6.79 kcal/mol) and Survivin (dGbind = -32.36 ± 1.29 kcal/mol). In vitro assays using HCT116 colorectal cancer cells revealed that 2,4-DTBP inhibited proliferation and promoted apoptosis in both a dose- and time-dependent manner. Fluorescence imaging and scanning electron microscopy illustrated the classical features associated with apoptosis upon 2,4-DTBP exposure. Cell cycle analysis through flow cytometry highlighted a G1 phase arrest and apoptosis assay demonstrated increased apoptotic cell population. Notably, western blotting results indicated a decreased expression of Bcl-2 and Survivin post-treatment. Considering the cytoprotective roles of Bcl-2 and Survivin through the inhibition of mitochondrial dysfunction, our findings of disrupted mitochondrial bioenergetics, characterized by reduced ATP production and oxygen consumption, further accentuate the functional impairment of these proteins. Overall, the integration of in silico and in vitro data suggests that 2,4-DTBP holds promise as a therapeutic agent targeting Bcl-2 and Survivin in colorectal cancer.

Natural Compounds in Non-Melanoma Skin Cancer: Prevention and Treatment

The elevated occurrence of non-melanoma skin cancer (NMSC) and the adverse effects associated with available treatments adversely impact the quality of life in multiple dimensions. In connection with this, there is a necessity for alternative approaches characterized by increased tolerance and lower side effects. Natural compounds could be employed due to their safety profile and effectiveness for inflammatory and neoplastic skin diseases. These anti-cancer drugs are often derived from natural sources such as marine, zoonotic, and botanical origins. Natural compounds should exhibit anti-carcinogenic actions through various pathways, influencing apoptosis potentiation, cell proliferation inhibition, and metastasis suppression. This review provides an overview of natural compounds used in cancer chemotherapies, chemoprevention, and promotion of skin regeneration, including polyphenolic compounds, flavonoids, vitamins, alkaloids, terpenoids, isothiocyanates, cannabinoids, carotenoids, and ceramides.

Kick-Starting Wound Healing: A Review of Pro-Healing Drugs

Cutaneous wound healing consists of four stages: hemostasis, inflammation, proliferation/repair, and remodeling. While healthy wounds normally heal in four to six weeks, a variety of underlying medical conditions can impair the progression through the stages of wound healing, resulting in the development of chronic, non-healing wounds. Great progress has been made in developing wound dressings and improving surgical techniques, yet challenges remain in finding effective therapeutics that directly promote healing. This review examines the current understanding of the pro-healing effects of targeted pharmaceuticals, re-purposed drugs, natural products, and cell-based therapies on the various cell types present in normal and chronic wounds. Overall, despite several promising studies, there remains only one therapeutic approved by the United States Food and Drug Administration (FDA), Becaplermin, shown to significantly improve wound closure in the clinic. This highlights the need for new approaches aimed at understanding and targeting the underlying mechanisms impeding wound closure and moving the field from the management of chronic wounds towards resolving wounds.

Macrofungal Mediated Biosynthesis of Silver Nanoparticles and Evaluation of Its Antibacterial and Wound-Healing Efficacy

Recently, the utilization of biological agents in the green synthesis of nanoparticles has been given interest. In this study, silver nanoparticles were synthesized from an aqueous extract of macrofungus (mushroom), namely Phellinus adamantinus, in a dark room using 20 µL of silver nitrate. Biosynthesized silver nanoparticles were confirmed by analyzing them using a UV-Vis (ultraviolet-visible) spectrophotometer. The synthesized silver nanoparticles were optimized at different pH and temperatures with various dosages of AgNO3 (silver nitrate) and fungal extracts. The synthesized AgNPs (silver nanoparticles) were characterized using TEM (transmission electron microscopy) and EDX (energy-dispersive X-ray) analyses, which confirmed the presence of silver nanoparticles. The size of the nanosilver particles was found to be 50 nm with higher stability. The mycosynthesized AgNPs showed effective antibacterial activity against strains of Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (E. coli and Pseudomonas aeruginosa) bacteria. The minimum inhibitory concentration (MIC) was found to be 3.125 μg/mL by MIC assay. The MTT assay (3-[4,5-dimethylthiazol-2-yl] 2,5-diphenyl-2H-tetrazolium bromide) was performed to study cytotoxicity, and reduced cell viability was recorded at 100 μg/mL. Silver-Polygalacturonic acid-Polyvinyl alcohol ((Ag-PGA)-PVA) nanofiber was prepared using the electrospinning method. The in vitro wound scratch assay was demonstrated to study the wound-healing efficacy of the prepared nanofiber. The wound-healing efficacy of the AgNP-incorporated nanofiber was found to be 20% after 24 h. This study will lay a platform to establish a unique route to the development of a novel nanobiomaterial and its application in antibacterial and wound-healing therapy.

Hydrolat of Helichrysum italicum promotes tissue regeneration during wound healing

Wound healing is a dynamic process involving different cell types with distinct roles according to the stages of healing. Fibroblasts and stem cells actively participate in tissue regeneration. A proper stimulation could contribute to enhance wound healing process-es. Helichrysum italicum (H. italicum) is a medical plant well described for its pharmacological, antimicrobial, and anti-inflammatory activities. Aim of the present work was to examine the effect of the hydrolat derivate from H. italicum on stem cells isolated from skin and fibroblasts in vitro in presence or absence of tissue damage. The viability and proliferation of all cell types cultured in dif-ferent conditions were analyzed by MTT and BrdU assays. Cell proliferation after wound was analyzed with scratch test. Also, the expression of the main genes involved in tissue repair was evaluated by RT-qPCR analysis. Here we describe the capability of hy-drolat of H. italicum to promote tissue regeneration after scratch test both in stem cells and in fibroblasts. Moreover, the gene ex-pression analysis revealed that, hydrolat of H. italicum is also able to enhance stemness related. In conclusion our results are en-couraging, highlighting novel regenerative properties of hydrolat of H. italicum and paving the way for future application of this wasting product in accelerating wound healing.

Evaluation of Oleogels Stabilized by Particles of Birch Outer Bark Extract through a Novel Approach

Structuring liquid oils into oleogels using natural and abundant biomass components as gelling agents is of great significance in fields such as foods, pharmaceuticals, and cosmetics. In this work, a more energy-efficient and technologically simpler approach for directly preparing birch outer bark extract particles containing oleogel was used. This method involves introducing birch outer bark extract particles into the oil phase directly from the extract solution, combining both the evaporation of solution and gel formation. As a result, stable oleogels of various vegetable oils (sunflower, almond, olive, and hemp seed) were obtained with birch outer bark extract particle contents of 4-10%. Infrared spectroscopy and particle size analysis confirmed that when increasing the content of extract particles in the oil, increasing self-assembly of extract particles via hydrogen bonding occurs, leading to the formation of a more structured network. This is consistent with gel strength values from rheological tests of oleogels, which also increased with particle concentration. The obtained oleogels showed important properties such as good tolerance to time-dependent deformation, shear thinning, and thermoreversibility.

Complement factor D regulates collagen type I expression and fibroblast migration to enhance human tendon repair and healing outcomes

Introduction

Dense connective tissues (DCTs) such as tendon, ligament, and cartilage are important stabilizers and force transmitters in the musculoskeletal system. The healing processes after DCT injuries are highly variable, often leading to degenerative changes and poor clinical outcome. Biomarkers in relation to repair quality for human DCTs, especially tendon are lacking. This study expands our previous findings and aimed to characterize the mechanisms by which a potential biomarker of good outcomes, complement factor D (CFD), regulates tendon healing.

Methods

Quantitative mass spectrometry (QMS) profiling of tissue biopsies from the inflammatory phase of healing (n = 40 patients) and microdialysates from the proliferative phase of healing (n = 28 patients) were used to identify specific biomarkers for tendon healing. Further bioinformatic and experimental investigations based on primary fibroblasts and fibroblast cell line were used to confirm the identified biomarkers.

Results

The QMS profiling of tissue biopsies from the inflammatory phase of healing identified 769 unique proteins, and microdialysates from the proliferative phase of healing identified 1423 unique proteins in Achilles tendon rupture patients. QMS-profiling showed that CFD expression was higher during the inflammatory- and lower during the proliferative healing phase in the good outcome patients. Further bioinformatic and experimental explorations based on both inflammatory and proliferative fibroblast models demonstrated that CFD potentially improved repair by regulating cell migration and modulating collagen type I (Col1a1) expression. Moreover, it was shown that the enhanced Col1a1 expression, through increased fibroblast migration, was correlated with the validated clinical outcome.

Discussion

The results of the current studies characterized underlying inflammatory- and proliferative healing mechanisms by which CFD potentially improved tendon repair. These findings may lead to improved individualized treatment options, as well the development of effective therapies to promote good long-term clinical outcomes after tendon and other DCT injuries.

Trial registration

http://clinicaltrials.gov, identifiers NCT02318472, NCT01317160.

Birch Bark Extract: A Review in Epidermolysis Bullosa

Birch bark extract (Filsuvez®; also known as the developmental name Oleogel-S10), a topical gel consisting of 10% dry birch bark extract and 90% sunflower oil, is the first therapy approved in the EU and UK for the treatment of partial thickness wounds associated with dystrophic and junctional epidermolysis bullosa (EB) in patients aged ≥ 6 months old. In the pivotal double-blind, randomized, vehicle-controlled, phase III EASE trial in patients with EB, the primary endpoint was met, in which birch bark extract relative to control gel significantly increased the proportion of patients with first complete target wound closure within 45 days. Moreover, patients treated with birch bark extract demonstrated several other positive findings in improving wound burden and wound-associated symptoms. The clinical benefits of birch bark extract were maintained in the 24-month open-label extension period of the EASE trial. Birch bark extract was generally well tolerated in patients with EB, with the tolerability profile being similar to that of control gel. Current evidence indicates that birch bark extract is an effective, emerging treatment option for patients with dystrophic and junctional EB.

Effect of Betulin Colloidal Particles on Proliferation and Cytokine Secretion of Human Skin Fibroblasts

The aim of the study was to obtain untreated and treated betulin colloidal particles and assess their effect on the viability, morphology, proliferation and cytokine secretion of human dermal fibroblasts. To improve bioavailability, betulin treatment was performed by an antisolvent precipitation technique. The average particle size after treatment in the aqueous dispersion decreased from 552.9 ± 11.3 to 278.2 ± 1.6 nm. Treated betulin colloidal particles showed no cytotoxicity up to a concentration of 400 µg·mL-1 in the colorimetric tetrazolium salt viability test (CCK-8). Moreover, the cell morphology was not changed in the presence of betulin colloidal particles at a concentration range from 0.78 to 400 µg·mL-1. The obtained results also show that betulin particles induce the secretion of the proinflammatory and angiogenesis-stimulating cytokine IL-8. However, further studies would be required to clarify the mechanism of IL-8 secretion induction.

Pharmacological Potential of Betulin as a Multitarget Compound

Betulin is a natural triterpene, usually from birch bark, known for its potential wound-healing properties. Despite having a wide range of pharmacological targets, no studies have proposed betulin as a multitarget compound. Betulin has protective effects against cardiovascular and liver diseases, cancer, diabetes, oxidative stress, and inflammation. It reduces postprandial hyperglycemia by inhibiting α-amylase and α-glucosidase activity, combats tumor cells by inducing apoptosis and inhibiting metastatic proteins, and modulates chronic inflammation by blocking the expression of proinflammatory cytokines via modulation of the NFκB and MAPKs pathways. Given its potential to influence diverse biological networks with high target specificity, it can be hypothesized that betulin may eventually become a new lead for drug development because it can modify a variety of pharmacological targets. The summarized research revealed that the diverse beneficial effects of betulin in various diseases can be attributed, at least in part, to its multitarget anti-inflammatory activity. This review focuses on the natural sources, pharmacokinetics, pharmacological activity of betulin, and the multi-target effects of betulin on signaling pathways such as MAPK, NF-κB, and Nrf2, which are important regulators of the response to oxidative stress and inflammation in the body.

Novel compounds discovery approach based on UPLC-QTOF-MS/MS chemical profile reveals birch bark extract anti-inflammatory, -oxidative, and -proliferative effects

ETHNOPHARMACOLOGICAL RELEVANCE

Betula pendula subsp. Mandshurica (Regel) Ashburner & McAll. Cortex (birch bark) is a globally traditional medicine for treating multiple inflammatory diseases. Its records are included in the Compendium of Materia Medica and other ancient medical literatures. However, uncovering its chemical profile and exploring novel biologically active compounds from birch bark remains a significant challenge.

AIM OF THE STUDY

To uncover the anti-inflammatory, -oxidative, and -proliferative mechanisms and potentially effective compounds of birch bark extract by combing chemical profiling, isolation, identification, together with in vivo, in vitro, and silico evaluation.

MATERIALS AND METHODS

Ultra-performance liquid chromatography coupled to quadrupole time-of-flight tandem mass spectrometry (UPLC-QTOF-MS/MS) was used to obtain the chemical profile of birch bark extract. The new compounds were obtained via column chromatography and analyzed using X-ray diffraction and electronic circular dichroism for absolute configuration confirmation. The zebrafish caudal fin inflammation-induced model, qPCR, and Western blot analysis were used to explore the effects and underlying mechanisms of birch bark extract. In vitro cytotoxicity assays and kinases screening conducted to gain preliminary insight into the anti-proliferative effects of birch bark extract and its isolated compounds. In addition, in-silico molecular docking was performed to investigate the putative mechanism.

RESULTS

UPLC-QTOF-MS/MS chemical profiles revealed 105 compounds in birch bark extract, with 80 of these were first reported in B. pendula subsp. Mandshurica cortex. We selected five compounds speculated as novel and isolated three ones (one triterpenoid derivative and two lupine series triterpenoids) for further analysis. Birch bark extract exerted antioxidative and anti-inflammatory effects on zebrafish, as shown by the downregulated reactive oxygen species levels and COX-2α, IL-1β, and TNF-α expression, which occurred through NF-ĸB signaling pathway activation. The in vitro anti-proliferative effects of birch bark extract and compound 44 were also unveiled. Moreover, the putative anti-tumor mechanism of compound 44 was revealed using kinase screening and in-silico molecular docking.

CONCLUSIONS

This study provided a predictable chemical profile and demonstrated the pharmacological effects of birch bark extract, elucidated the mechanism of this traditional Chinese medicine and suggested it as a novel anti-cancer candidate.

New Data on Anti-Inflammatory and Wound Healing Potential of Transgenic Senna obtusifolia Hairy Roots: In Vitro Studies

Asthma is an inflammatory disease whose etiology remains unclear. Its characteristics encompass a wide range of clinical symptoms, inflammatory processes, and reactions to standard therapies. Plants produce a range of constitutive products and secondary metabolites that may have therapeutic abilities. The aim of this study was to determine the effects of Senna obtusifolia transgenic hairy root extracts on virus-induced airway remodeling conditions. Three cell lines were incubated with extracts from transformed (SOA4) and transgenic (SOPSS2, with overexpression of the gene encoding squalene synthase 1) hairy roots of Senna obtusifolia in cell lines undergoing human rhinovirus-16 (HRV-16) infection. The effects of the extracts on the inflammatory process were determined based on the expression of inflammatory cytokines (IL-8, TNF-α, IL-1α and IFN-γ) and total thiol content. The transgenic Senna obtusifolia root extract reduced virus-induced expression of TNF, IL-8 and IL-1 in WI-38 and NHBE cells. The SOPSS2 extract reduced IL-1 expression only in lung epithelial cells. Both tested extracts significantly increased the concentration of thiol groups in epithelial lung cells. In addition, the SOPPS2 hairy root extract yielded a positive result in the scratch test. SOA4 and SOPPS2 Senna obtusifolia hairy root extracts demonstrated anti-inflammatory effects or wound healing activity. The SOPSS2 extract had stronger biological properties, which may result from a higher content of bioactive secondary metabolites.

Design and evaluation of sodium alginate-based hydrogel dressings containing Betula utilis extract for cutaneous wound healing

Traditional wound dressings have a limited capacity to absorb exudates, are permeable to microbes, and may adhere to wounds, which leads to secondary injuries. Hydrogels are promising alternative dressings to overcome the above challenges. In this study, we developed sodium alginate-based hydrogel films loaded with Betula utilis bark extract. These films were prepared via solvent-casting crosslinking method and evaluated for wound healing activity. Prepared films were 0.05-0.083 mm thick, flexible with folding endurance ranging from 197-203 folds, which indicates good physical properties. Optimized formulations exhibited successful loading of extract in the film matrix without any interaction as confirmed by FTIR. Maximum zone of inhibition against Gram-positive and Gram-negative bacteria was achieved by optimum formulation (B6), i.e., 19 mm and 9 mm, respectively, with > 90% scavenging activity. Furthermore, this optimum formulation (B6) was able to achieve 93% wound contraction in rats. Histograms of the optimized formulation treated group also revealed complete reepithelization of wounds. Conclusively, our extract-loaded hydrogel dressing successfully demonstrated its potential for cutaneous wound healing.

Antioxidative and Antimicrobial Evaluation of Bark Extracts from Common European Trees in Light of Dermal Applications

Plant species have developed effective defense strategies for colonizing diverse habitats and protecting themselves from numerous attacks from a wide range of organisms, including insects, vertebrates, fungi, and bacteria. The bark of trees in particular constitutes a number of components that protect against unwanted intruders. This review focuses on the antioxidative, dermal immunomodulatory, and antimicrobial properties of bark extracts from European common temperate trees in light of various skin pathogens, wound healing, and the maintenance of skin health. The sustainability aspect, achieved by utilizing the bark, which is considered a byproduct in the forest industry, is addressed, as are various extraction methods applied to retrieve extracts from bark.

Pinoresinol stimulates keratinocyte proliferation and downregulates TNF-α secretion in peripheral blood mononuclear cells: An experimental in vitro study

Background and Aims

Natural coniferous resins are used in traditional medicine for the treatment of skin wounds. Coniferous wood resins ("callus" resin) are a mixture of abietic (resin) acids, lignans such as pinoresinol, and p-coumaric acid. The wound-healing properties of resins are thought to be related to their antimicrobial properties, but also to their effects on cell proliferation and inflammation. The purpose of this study was to identify and investigate the effects of novel aqueous dispersions of resin and its main components in the proliferation of human primary keratinocytes in vitro and in the expression of proinflammatory cytokines in human peripheral blood mononuclear cells.

Methods

The proliferation studies were performed under low and high calcium conditions with or without added growth stimulators at the time points of 2 and 6 days using AlamarBlue Cell Viability Reagent. The cytokine release assay was carried out by incubating the cells with the test articles for 18 h, after which the levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-6, and IL-8 were measured in the supernatant by enzyme-linked immunosorbent assay.

Results

Resin and the purified lignan PINO, but not p-coumaric acid or abietic acid (industrial tall oil rosin), enhanced the proliferation of human keratinocytes in vitro and inhibited the expression of TNF-α, and to a lesser extent the expression of IL-1β in peripheral blood mononuclear cells.

Conclusions

In this study, novel aqueous dispersions of spruce resin were used to investigate the effects of main resin components on keratinocyte proliferation and on the expression of key proinflammatory cytokines known to be associated with chronic wounds. The observations suggest that lignans, such as PINO, but not resin acids, are the components of resins that mediate the proliferative and TNF-α-suppressing effects. Lignans including PINO were identified as novel potential compounds in the treatment of chronic skin ulcers.

Inhibition of a broad range of SARS-CoV-2 variants by antiviral phytochemicals in hACE2 mice

Although several vaccines and antiviral drugs against SARS-CoV-2 are currently available, control and prevention of COVID-19 through these interventions is limited due to inaccessibility and economic issues in some regions and countries. Moreover, incomplete viral clearance by ineffective therapeutics may lead to rapid genetic evolution, resulting in the emergence of new SARS-CoV-2 variants that may escape the host immune system as well as currently available COVID-19 vaccines. Here, we report that phytochemicals extracted from Chlorella spp. and Psidium guajava possess broad-spectrum antiviral activity against a range of SARS-CoV-2 variants. Through chromatography-based screening, we identified four bioactive compounds and subsequently demonstrated their potential antiviral activities in vivo. Interestingly, in hACE2 mice, treatment with these compounds significantly attenuates SARS-CoV-2-induced proinflammatory responses, demonstrating their potential anti-inflammatory activity. Collectively, our study suggests that phytochemicals from edible plants may be readily available therapeutics and prophylactics against multiple SARS-CoV-2 strains and variants.

Botanical Drugs in Traditional Chinese Medicine With Wound Healing Properties

Chronic and unhealed wound is a serious public problem, which brings severe economic burdens and psychological pressure to patients. Various botanical drugs in traditional Chinese medicine have been used for the treatment of wounds since ancient time. Nowadays, multiple wound healing therapeutics derived from botanical drugs are commercially available worldwide. An increasing number of investigations have been conducted to elucidate the wound healing activities and the potential mechanisms of botanical drugs in recent years. The aim of this review is to summarize the botanical drugs in traditional Chinese medicine with wound healing properties and the underlying mechanisms of them, which can contribute to the research of wound healing and drug development. Taken together, five botanical drugs that have been developed into commercially available products, and 24 botanical drugs with excellent wound healing activities and several multiherbal preparations are reviewed in this article.

A clickable photoaffinity probe of betulinic acid identifies tropomyosin as a target

Target identification of bioactive compounds is important for understanding their mechanisms of action and provides critical insights into their therapeutic utility. While it remains a challenge, unbiased chemoproteomics strategy using clickable photoaffinity probes is a useful and validated approach for target identification. One major limitation of this approach is the efficient synthesis of appropriately substituted clickable photoaffinity probes. Herein, we describe an efficient and consistent method to prepare such probes. We further employed this method to prepare a highly stereo-congested probe based on naturally occurring triterpenoid betulinic acid. With this photoaffinity probe, we identified tropomyosin as a novel target for betulinic acid that can account for the unique biological phenotype on cellular cytoskeleton induced by betulinic acid.

Antimicrobial Activity and Wound-Healing Capacity of Birch, Beech and Larch Bark Extracts

Bark is a major by-product of woodworking industries. The contents of several wood species are known to harbor antimicrobial, antiviral, anti-inflammatory and wound-healing capacities. The aim of this work was to identify beneficial properties of Austrian larch, birch and beech bark extracts for their potential usage as additives or active ingredients in dermatological applications. Bacterial agar diffusion assay and resazurin-based broth microdilution assay were used to evaluate anti-bacterial activity. To gain more insight into the cellular response to bark extracts, viability-, scratch-assays and ELISAs were performed. Birch and beech extracts showed strong antimicrobial activities against Gram-positive bacteria, including Cutibacterium acnes, Staphylococcus epidermidis and MRSA. Wound closure was enhanced with birch and beech extracts as compared to controls in the scratch-assays. Whereas beneficial properties of birch bark components have previously been described, the similar effects of beech extracts are novel. The combined positive effect on wound-healing and antimicrobial activity has great potential for the treatment of various skin diseases, including acne in future dermal applications.

The Activity of Combination of Ethanol Extract of Artocarpus lacucha Buch.-Ham and Anredera cordifolia Steenis Leaves to Increase Wound Healing Process on NIH-3T3 Cell Line

AIM: This study aims to determine the effect of the combination of ethanol extract of Artocarpus lacucha Buch.-Ham and Anredera cordifolia Steenis leaves to increase cell proliferation and increase VEGFR-2 expression of NIH-3T3. METHODS: The samples used were Artocarpus lacucha Buch.-Ham and Anredera cordifilia Steenis leaves. The powder of simples was extracted using ethanol 80% with maceration method. The effect of extract combination on proliferation was evaluated using the MTT method. Wound healing assay was established by a cell migration method, and VEGFR-2 expression was determined using RT-PCR. RESULTS: The effect of combination of ethanol extract of Artocarpus lacucha leaves (EEALL) and ethanol extract of Anredera cordifolia leaves (EEACL) on cell proliferation after 24h, 48h and 72h incubation found as viable cells were showed (124.33 ± 0.32%; 128.52 ± 0.41%; 118.35 ± 0.22%). Percent of wound closed after 24 h and 48 h incubation are 64.88 ± 0.90% and 100.00 ± 0.00%, and expression of VEGFR-2 increased from 1 (control) to 1.58 ± 0.02. CONCLUSION: The results suggest that a combination of EEALL and EEACL (37.5 μg/mL−37.5 μg/mL) is effective in increasing cells proliferation and hence wound healing process.

Wound closure, angiogenesis and antibacterial behaviors of tetracalcium phosphate/hydroxyethyl cellulose/hyaluronic acid/gelatin composite dermal scaffolds

Polymeric and tetracalcium phosphate (TTCP)-containing polymeric scaffolds were fabricated using a freeze-drying technique, with a homogenous solution of hydroxyethyl cellulose (HEC)/hyaluronic acid (HA)/gelatin (G) or suspension of 15 or 20% TTCP) particles in HEC/HA/G solution. The morphology, phase composition, chemical bands, and swelling behavior of the scaffold were determined. In vitro fibroblast cell viability and migration potential of the scaffolds were determined by MTT, live/dead staining, and scratch assay for wound healing. The in vivo chick embryo angiogenesis test was also carried out. Finally, the initial antibacterial activity of the scaffolds was determined using Staphylococcus aureus. The scaffolds exhibited an enormous porous structure in which the size of pores increased by the presence of TTCP particles. While the polymeric scaffold was amorphous, the formation of low crystalline hydroxyapatite phase and the initial TTCP particles was determined in the composition of TTCP-added scaffolds. TTCP increased swelling behavior of the polymeric scaffold in PBS. The results demonstrated that the amount of TTCP was a crucial factor in cell life. A high concentration of TTCP could restrict cell viability, although all the scaffolds were nontoxic. The scratch assessments determined better cell migration and wound closure in treating with TTCP-containing scaffolds so that after 24 h, a wound closure of 100% was observed. Furthermore, TTCP-incorporated scaffolds significantly improved the angiogenesis, in the chick embryo test. The presence of TTCP had a significant effect on reducing the bacterial activity and 20% TTCP-containing scaffold exhibited better antibacterial activity than the others.

Exudates of Picea abies, Pinus nigra, and Larix decidua: Chromatographic Comparison and Pro-Migratory Effects on Keratinocytes In Vitro

Balms and resins of Picea abies, Larix decidua, and Pinus nigra are traditionally used to treat wounds. Three chromatographic techniques differing in separation capacity and technical demands were employed to distinguish among these plant exudates. A TLC method was established for fingerprint comparison, providing a quick overview of a large number of samples at low cost. HPLC-DAD (RP18) and UHPSFC-DAD (Torus 2-Picolylamin), hyphenated to ESI-MS, represented orthogonal chromatographic systems with high separation performance. The developed methods allow for the separation and detection of major and minor constituents belonging to different compound classes (phenyl carboxylic acids, lignans, diterpene resin acids). The qualitative compositions of the diterpene resin acids, the main compounds in the exudates, were comparable in all three genera. Differences were detected in the distribution of hydroxylated diterpene resin acids, pinoresinol, and hydroxycinnamic acids. The three tested chromatographic systems with varying demands on lab equipment offer appropriate tools for the quality assessment of Picea abies, Larix decidua, and Pinus nigra. The extracts were furthermore tested at three different concentrations (10 µg/mL, 3 µg/mL, and 1 µg/mL) for boosted re-epithelialization, a crucial step in the wound-healing process, in an in vitro HaCaT keratinocyte-based scratch assay. Lysophosphatidic acid (LPA, 10 µM) and extracts of several medicinal plants well known for their wound-healing properties (birch, marigold, St. John's wort, manuka honey) were used as positive controls. Picea abies and Pinus nigra showed concentration dependency; significant activity was measured for Larix decidua at 3 µg/mL.

Plant-based Natural Products for Wound Healing: A Critical Review

Wound healing is an intricate process consisting of four overlapping phases, namely hemostasis, inflammation, proliferation, and remodelling. Effective treatment of wounds depends upon the interaction of appropriate cell types, cell surface receptors, and the extracellular matrix with the therapeutic agents. Several approaches currently used for treating wounds, such as advanced wound dressing, growth factor therapy, stem cell therapy, and gene therapy, are not very effective and lead to impaired healing. Further, repeated use of antibiotics to treat open wounds leads to multi- drug resistance. Today there is considerable interest in plant-based drugs as they are believed to be safe, inexpensive, and more suitable for chronic wounds. For example, a large number of plant- based extracts and their bioactive compounds have been investigated for wound healing. In recent years the structural and mechanistic diversity of natural products have become central players in the search for newer therapeutic agents. In the present review, a thorough critical survey of the traditionally used plant-based drugs used worldwide for wound healing with special reference to the natural products/bioactive compounds isolated and screened is presented. It is hoped that this review will attract the attention of the research community involved in newer drug design and development for wound healing.

Lecithin-based nanoemulsions of traditional herbal wound healing agents and their effect on human skin cells

In previous studies, lecithin-based nanoemulsions (NEs) have been shown to be skin friendly drug carrier systems. Due to their nontoxic properties, NEs might also be suitable as wound healing agents. Hence, different O/W NEs based on lecithin Lipoid® S 75 and plant oils or medium chain triglycerides were produced and characterised. Two lipophilic natural wound healing agents, a betulin-enriched extract from birch bark (BET) and a purified spruce balm (PSB), were successfully incorporated and their effects on primary human skin cells were studied in vitro. MTT, BrdU and scratch assays uncovered the positive influence of the drug-loaded NEs on cell viability, proliferation and potential wound closure. Compared to control formulations, the NEs loaded with either BET or PSB led to higher cell viability rates of fibroblasts and keratinocytes. Higher proliferative activity of keratinocytes and fibroblasts was observed after the treatment, which is a prerequisite for wound closure. Indeed, in scratch assays NEs with PSB and notably BET showed significantly ameliorated wound closure rates than the negative control (unloaded NEs) and the positive control (NEs with dexpanthenol). Our findings suggest that BET and PSB are outstanding wound healing drugs and their incorporation into lecithin-based NEs may represent a valid strategy for wound care.

Transcriptome analysis of North American sweet birch (Betula lenta) revealed a higher expression of genes involved in the biosynthesis of secondary metabolites than European silver birch (B. pendula)

The North American Betula lenta L. (sweet birch) has been used for medicinal reasons for centuries by native Americans. Although sophisticated technologies have rapidly been developed, a large information gap has been observed regarding genetic regulators of medicinally important compounds in sweet birch. Very little is known on the different genes involved in secondary metabolic biosynthesis in sweet birch. To gain a deeper insight into genetic factors, we performed a transcriptome analysis of each three biological samples from different independent trees of sweet and European silver birch (B. pendula Roth). This allowed us to precisely quantify the transcripts of about 24,000 expressed genes including 29 prominent candidate genes putatively involved in the biosynthesis of secondary metabolites like terpenoids, and aromatic benzoic acids. A total number of 597 genes were differentially expressed between B. lenta and B. pendula, while 264 and 210 genes showed upregulation in the bark and leaf of B. lenta, respectively. Moreover, we identified 39 transcriptional regulatory elements, involved in secondary metabolite biosynthesis, upregulated in B. lenta. Our study demonstrated the potential of RNA sequencing to identify candidate genes interacting in secondary metabolite biosynthesis in sweet birch. The candidate genes identified in this study could be subjected to genetic engineering to functionally characterize them in sweet birch. This knowledge can be beneficial to the increase of therapeutically important compounds.

Synthesis of erythrodiol C-ring derivatives and their activity against Chlamydia trachomatis

To develop new potential agents against Chlamydia trachomatis among oleanane type triterpenoids the synthesis, spectral and X-ray analysis as well as antimicrobial screening of C-12 oxygen and nitrogen derivatives of erythrodiol is presented. The reduction of methyl 3β-acetoxy-12-oxo-oleanoate with LiAlH₄ led to isomeric erythrodiol 12β- and 12α-hydroxy-derivatives, their stereochemistry with respect to the position of hydroxyl-group at C-12 was determined based on the multiplets splitting patterns, the magnitude of the spin-spin interaction, and NOESY interactions. Methyl 3β-acetoxy-12-oxo-oleanoate was transformed to 12E-hydroxyimino- and 12E-methoxyimino-derivatives by the interaction with NH₂OH∙HCl or CH₃ONH₂∙HCl, respectively. By Beckmann rearrangement with SOCl₂ in dioxane 12E-oxime was converted to C-lactame and its following reduction with LiAlH₄ in THF or dioxane led to erythrodiol C-azepanone or C-azepane derivatives. The structure 3-O,12-N-bis-acetyl-derivative of C-azepane-erythrodiol was confirmed by the single crystal X-ray analysis. Erythrodiol 12β-hydroxy- and C-azepane derivatives were found to be lead compounds with significant activity against C. trachomatis with MIC 1.56 and 3.125 μg/mL. Molecular docking was employed to suggest potential binding interaction, the tested compounds are likely to act as Cdu1 protein inhibitors while 12β-hydroxy-erythrodiol exhibited the highest affinity towards this respective target protein. These results indicated that C-ring oxygen and nitrogen erythrodiol derivatives might be considered for further research in the design of antibacterial agents against Chlamydia trachomatis.

Transcriptomic Repositioning Analysis Identifies mTOR Inhibitor as Potential Therapy for Epidermolysis Bullosa Simplex

Expression-based systematic drug repositioning has been explored to predict novel treatments for a number of skin disorders. In this study, we utilize this approach to identify, to our knowledge, previously unreported therapies for epidermolysis bullosa simplex (EBS). RNA sequencing analysis was performed on skin biopsies of acute blisters (<1 week old) (n = 9) and nonblistered epidermis (n = 11) obtained from 11 patients with EBS. Transcriptomic analysis of blistered epidermis in patients with EBS revealed a set of 1,276 genes dysregulated in EBS blisters. The IL-6, IL-8, and IL-10 pathways were upregulated in the epidermis from EBS. Consistent with this, predicted upstream regulators included TNF-α, IL-1β, IL-2, IL-6, phosphatidylinositol 3-kinase, and mTOR. The 1,276 gene EBS blister signature was integrated with molecular signatures from cell lines treated with 2,423 drugs using the Connectivity Map CLUE platform. The mTOR inhibitors and phosphatidylinositol 3-kinase inhibitors most opposed the EBS signature. To determine whether mTOR inhibitors could be used clinically in EBS, we conducted an independent pilot study of two patients with EBS treated with topical sirolimus for painful plantar keratoderma due to chronic blistering. Both individuals experienced marked clinical improvement and a notable reduction of keratoderma. In summary, a computational drug repositioning analysis successfully identified, to our knowledge, previously unreported targets in the treatment of EBS.

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.

Preparation and Characterization of Electrospun Polylactic Acid (PLA) Fiber Loaded with Birch Bark Triterpene Extract for Wound Dressing

Drug-loaded electrospun fibers have attracted increasing attention as a promising wound dressing material due to their capability of preventing from infections and inflammation and maintaining an appropriate environment for wound healing. In this study, polylactic acid (PLA), which is widely used in wound management, was chosen as electrospinnable polymer. A triterpene extract (TE) from the outer bark of birch known for its anti-inflammatory, antiviral, antibacterial, and wound healing effects was chosen to produce TE-loaded PLA electrospun fibers for wound dressing. A binary solvent system of dichloromethane (DCM) and dimethyl sulfoxide (DMSO) was employed, and the ratio of the solvents was optimized for preparing smooth and uniform fibers. The morphology of TE-loaded PLA electrospun fibers was investigated by scanning electron microscopy (SEM). The entrapment of TE in PLA fibers was confirmed by confocal laser scanning microscopy (CLSM). Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) were used to analyze the solid state of TE in PLA fibers. The release behavior of TE was assayed by a shaking flask method for a period of 96 h. The results revealed that TE-loaded electrospun PLA microfibers could be reliably prepared and are promising future candidates in wound therapy.

The Effect of the New Lupeol Derivatives on Human Skin Cells as Potential Agents in the Treatment of Wound Healing

Skin barrier damage can be the result of various external factors including heat, radiation, chemicals and many others. Any interruption of the skin barrier integrity causes the exposure of the organism to harmful environmental factors. Therefore, there is an urgent need to develop novel therapeutics characterized by high bioavailability and effectiveness in skin damage recovery. Birch bark is known as a clinically proven, traditional medicinal remedy to accelerate wound healing. Lupeol, one of the main birch bark ingredients, shows a wide range of biological activity beneficial to the skin. The purpose of the research was to determine the influence of new lupeol derivatives on keratinocyte and fibroblast migration and proliferation, as well as to investigate various mechanisms of their antioxidant activity. The chemical modification of lupeol structure was intended to obtain more effective therapeutics characterized by higher bioavailability, permeability and safety of use. The novel triterpenes presented in this study were evaluated as the potential active ingredients preventing skin tissue degradation. Lupeol esters influence skin cells' motility and proliferation. Importantly, they are able to reduce reactive oxygen species and act indirectly by protecting the skin protein structure from being oxidized by free radicals.

Plant Products as Inhibitors of Coronavirus 3CL Protease

Background: The ongoing COVID-19 pandemic has created an alarming situation due to extensive loss of human lives and economy, posing enormous threat to global health security. Till date, no antiviral drug or vaccine against SARS-CoV-2 has reached the market, although a number of clinical trials are under way. The viral 3-chymotrypsin-like cysteine protease (3CLpro), playing pivotal roles in coronavirus replication and polyprotein processing, is essential for its life cycle. In fact, 3CLpro is already a proven drug discovery target for SARS- and MERS-CoVs. This underlines the importance of 3CL protease in the design of potent drugs against COVID-19. Methods: We have collected one hundred twenty-seven relevant literatures to prepare the review article. PubMed, Google Scholar and other scientific search engines were used to collect the literature based on keywords, like "SARS-CoVs-3CL protease," "medicinal plant and anti-SARS-CoVs-3CL protease" published during 2003-2020. However, earlier publications related to this topic are also cited for necessary illustration and discussion. Repetitive articles and non-English studies were excluded. Results: From the literature search, we have enlisted medicinal plants reported to inhibit coronavirus 3CL protease. Some of the plants like Isatis tinctoria L. (syn. Isatis indigotica Fort.), Torreya nucifera (L.) Siebold and Zucc., Psoralea corylifolia L., and Rheum palmatum L. have exhibited strong anti-3CLpro activity. We have also discussed about the phytochemicals with encouraging antiviral activity, such as, bavachinin, psoralidin, betulinic acid, curcumin and hinokinin, isolated from traditional medicinal plants. Conclusion: Currently, searching for a plant-derived novel drug with better therapeutic index is highly desirable due to lack of specific treatment for SARS-CoV-2. It is expected that in-depth evaluation of medicinally important plants would reveal new molecules with significant potential to inhibit coronavirus 3CL protease for development into approved antiviral drug against COVID-19 in future.

The Phospholipid Research Center: Current Research in Phospholipids and Their Use in Drug Delivery

This review summarizes the research on phospholipids and their use for drug delivery related to the Phospholipid Research Center Heidelberg (PRC). The focus is on projects that have been approved by the PRC since 2017 and are currently still ongoing or have recently been completed. The different projects cover all facets of phospholipid research, from basic to applied research, including the use of phospholipids in different administration forms such as liposomes, mixed micelles, emulsions, and extrudates, up to industrial application-oriented research. These projects also include all routes of administration, namely parenteral, oral, and topical. With this review we would like to highlight possible future research directions, including a short introduction into the world of phospholipids.

Tetracyclic and Pentacyclic Triterpenes with High Therapeutic Efficiency in Wound Healing Approaches

Wounds are among the most common skin conditions, displaying a large etiological diversity and being characterized by different degrees of severity. Wound healing is a complex process that involves multiple steps such as inflammation, proliferation and maturation and ends with scar formation. Since ancient times, a widely used option for treating skin wounds are plant- based treatments which currently have become the subject of modern pharmaceutical formulations. Triterpenes with tetracyclic and pentacyclic structure are extensively studied for their implication in wound healing as well as to determine their molecular mechanisms of action. The current review aims to summarize the main results of in vitro, in vivo and clinical studies conducted on lupane, ursane, oleanane, dammarane, lanostane and cycloartane type triterpenes as potential wound healing treatments.

Influence of PVA Molecular Weight and Concentration on Electrospinnability of Birch Bark Extract-Loaded Nanofibrous Scaffolds Intended for Enhanced Wound Healing

Triterpenes from the outer bark of birch (TE) are known for various pharmacological effects including enhanced wound healing. Apart from an already authorized oleogel, electrospun nanofiber mats containing these triterpenes in a polyvinyl alcohol (PVA) matrix appear to be an advantageous application form. The effects of PVA molecular weight and concentration on the fiber morphology have been investigated. Three different molecular weights of PVA ranging from 67 to 186 kDa were used. The concentration of PVA was varied from 5 to 20 wt%. Polymer solutions were blended with colloidal dispersions of birch bark extract at a weight ratio of 60:40 (wt.%). The estimated viscosity of polymer solutions was directly linked to their concentration and molecular weight. In addition, both pure and blended solutions showed viscoelastic properties with a dominant viscous response in the bulk. Fiber morphology was confirmed using scanning electron microscopy (SEM). Both polymer concentration and molecular weight were found to be significant factors affecting the diameter of the fibers. Fiber diameter increased with a higher molecular weight and polymer concentration as more uniform fibers were obtained using PVA of higher molecular weight (146-186 kDa). In vitro drug release and ex vivo permeation studies indicated a faster drug release of betulin from electrospun scaffolds with lower PVA molecular weight. Our research suggests that the fabricated TE-loaded PVA electrospun dressings represent potential delivery systems of TE for wound care applications.

Dietary Erythrodiol Modifies Hepatic Transcriptome in Mice in a Sex and Dose-Dependent Way

Erythrodiol is a terpenic compound found in a large number of plants. To test the hypotheses that its long-term administration may influence hepatic transcriptome and this could be influenced by the presence of APOA1-containing high-density lipoproteins (HDL), Western diets containing 0.01% of erythrodiol (10 mg/kg dose) were provided to Apoe- and Apoa1-deficient mice. Hepatic RNA-sequencing was carried out in male Apoe-deficient mice fed purified Western diets differing in the erythrodiol content. The administration of this compound significantly up- regulated 68 and down-regulated 124 genes at the level of 2-fold change. These genes belonged to detoxification processes, protein metabolism and nucleic acid related metabolites. Gene expression changes of 21 selected transcripts were verified by RT-qPCR. Ccl19-ps2, Cyp2b10, Rbm14-rbm4, Sec61g, Tmem81, Prtn3, Amy2a5, Cyp2b9 and Mup1 showed significant changes by erythrodiol administration. When Cyp2b10, Dmbt1, Cyp2b13, Prtn3 and Cyp2b9 were analyzed in female Apoe-deficient mice, no change was observed. Likewise, no significant variation was observed in Apoa1- or in Apoe-deficient mice receiving doses ranging from 0.5 to 5 mg/kg erythrodiol. Our results give evidence that erythrodiol exerts a hepatic transcriptional role, but this is selective in terms of sex and requires a threshold dose. Furthermore, it requires an APOA1-containing HDL.

Optimized Birch Bark Extract-Loaded Colloidal Dispersion Using Hydrogenated Phospholipids as Stabilizer

This study investigated the formulation and processing of aqueous colloidal dispersions containing a birch bark dry extract (TE) as the active substance and hydrogenated phospholipids (Phospholipon 90H) as stabilizer, which can be used in the preparation of electrospun wound dressings. Colloidal dispersions manufactured using a two-stage homogenization process had a bimodal particle size distribution, which was most significantly (p < 0.0001) affected by the phospholipid content. The size of the single particles decreased from an average particle size of about 4 µm to a particle size of approximately 400 nm. Dynamic interfacial tension studies performed using a profile analysis tensiometer (PAT) showed that the phospholipids strongly declined the interfacial tension, whereas a further decrease was observed when phospholipids were combined with birch bark extract. Interfacial viscoelasticity properties analyzed using the oscillating drop technique resulted in an increase of both interfacial elasticity and viscosity values. These results indicated that the phospholipids are preferentially located at the lipophilic/water interface and a stable film is formed. Furthermore, the results point to a synergistic interaction between phospholipids and TE. Confocal Raman microscopy (CRM) suggested that the TE is predominantly located in the oil phase and the phospholipids at the interface.

Electrospun Bioactive Wound Dressing Containing Colloidal Dispersions of Birch Bark Dry Extract

Novel birch bark dry extract (TE)-loaded polyvinyl alcohol (PVA) fiber mats intended for wound therapy were developed through an electrospinning process. Colloidal dispersions containing TE as the active substance were prepared by the high-pressure homogenization (HPH) technique using hydrogenated phospholipids as stabilizer. Subsequently, the colloidal dispersions were blended with aqueous PVA solutions in the ratio of 60:40 (wt.%) and electrospun to form the nanofiber mats. Fiber morphology examined using scanning electron microscopy (SEM) indicated that fibers were uniform and achieved diameters in the size range of 300–1586 nm. Confocal Raman spectral imaging gave good evidence that triterpenes were encapsulated within the electrospun mats. In vitro drug release and ex vivo permeation studies indicated that the electrospun nanofibers showed a sustained release of betulin, the main component of birch bark dry extract, making the examined dressings highly applicable for several wound care applications. Ex vivo wound healing studies proved that electrospun fiber mats containing TE accelerated wound healing significantly more than TE oleogel, which was comparable to an authorized product that consists of TE and sunflower oil and has proved to enhance wound healing. Therefore, our results conclude that the developed TE-PVA-based dressings show promising potential for wound therapy, an area where effective remedy is needed.

Leading edge: emerging drug, cell, and gene therapies for junctional epidermolysis bullosa

INTRODUCTION

Junctional epidermolysis bullosa (JEB) is a rare inherited genetic disorder with limited treatments beyond palliative care. A major hallmark of JEB is skin blistering caused by functional loss or complete absence of major structural proteins of the skin. Impaired wound healing in patients with JEB gives rise to chronic cutaneous ulcers that require daily care. Wound care and infection control are the current standard of care for this patient population.

AREAS COVERED

This review covers research and clinical implementation of emerging drug, cell, and gene therapies for JEB. Current clinical trials use topical drug delivery to manipulate the inflammation and re-epithelialization phases of wound healing or promote premature stop codon readthrough to accelerate chronic wound closure. Allogeneic cell therapies for JEB have been largely unsuccessful, with autologous skin grafting emerging as a reliable method of resolving the cutaneous manifestations of JEB. Genetic correction and transplant of autologous keratinocytes have demonstrated persistent amelioration of chronic wounds in a subset of patients.

EXPERT OPINION

Emerging therapies address the cutaneous symptoms of JEB but are unable to attend to systemic manifestations of the disease. Investigations into the molecular mechanism(s) underpinning the failure of systemic allogeneic cell therapies are necessary to expand the range of effective JEB therapies.

Fibroblast Proliferation and Migration in Wound Healing by Phytochemicals: Evidence for a Novel Synergic Outcome

Wound-healing is a dynamic skin reparative process that results in a sequence of events, including inflammation, proliferation, and migration of different cell types as fibroblasts. Fibroblasts play a crucial role in repairing processes, from the late inflammatory phase until the fully final epithelization of the injured tissue. Within this context, identifying tools able to implement cell proliferation and migration could improve tissue regeneration. Recently, plants species from all over the world are coming out as novel tools for therapeutic applications thanks to their phytochemicals, which have antioxidant properties and can promote wound healing. In this paper, we aimed at investigating antioxidant activity of waste extracts from different medicinal plants, endemic of the Mediterranean area, on fibroblast proliferation and wound healing. We determined the amount of total phenols and anti-oxidant activity by ABTS assay. We then evaluated the cytotoxicity of the compounds and the proliferative capabilities of fibroblasts by scratch assay. Our results showed that waste extracts retain antioxidant and regenerative properties, inducing tissue re-establishment after environmental stress exposure. Taken together, our findings suggest that waste material could be used in the future also in combinations to stimulate wound healing processes and antioxidant responses in damaged skin.

New Herbal Biomedicines for the Topical Treatment of Dermatological Disorders

Herbal extracts and isolated plant compounds play an increasing role in the treatment of skin disorders and wounds. Several new herbal drugs, medicinal products and cosmetic products for the treatment of various skin conditions have been developed in recent years. In this nonsystematic review, we focus on herbal drugs that were tested in controlled clinical studies or in scientifically sound preclinical studies. The herbal biomedicines are intended to treat atopic dermatitis (St. John's wort, licorice, tormentil, bitter substances, evening primrose), psoriasis (araroba tree, lace flower, barberry bark, indigo, turmeric, olibanum, St. John's wort), actinic keratosis (birch bark, petty spurge), herpes simplex (lemon balm, sage and rhubarb), rosacea (green tea, licorice, tormentil) and acne vulgaris (tea tree oil, green tea, hop), or to improve photo protection (green tea, Dyer's weed, cocoa tree, carotinoids, licorice), aesthetic dermatology (licorice, pine bark, gotu kola) and wound healing (birch bark, onion).

The Activity of Hydrolyzed Virgin Coconut Oil to Increase Proliferation and Cyclooxygenase-2 Expression towards on NIH 3T3 Cell Line in Wound Healing Process

AIM:

This study aims to determine the effect of hydrolysed virgin coconut oil (HVCO) to increase cell proliferation, COX-2 expression of NIH 3T3.

METHODS:

The sample used was Virgin Coconut Oil (VCO). VCO was partially hydrolysed using lipase from Rhizomucor miehei (active on sn-1,3 position) to produce hydrolysed VCO (HVCO) composed of free fatty acids, 2-monoglycerides. Then acid value was determined. The effect of HVCO on proliferation was evaluated using the MTT method. Wound healing assay was established by a cell migration method, and COX-2 expression was determined using RT-PCR.

RESULTS:

Acid value is 135.89 ± 0.12 mg NaOH/g oil and free fatty acids (FFA) is 48.50 ± 0.06%. The effect of HVCO 62.5 µg/mL on cell proliferation after 24h, 48h, and 72h incubation found as viable cells are 109.24 ± 0.52%; 118.26 ± 0.91% and 106.59 ± 0.74%. Percent of wound closed after 24 h and 48 h incubation are 69.94 ± 0.54% and 100.00 ± 0.00%, and expression of COX-2 increased from 1 (control) to 1.83 (HVCO).

CONCLUSION:

The results suggest that HVCO is effective to increase cells proliferation and hence wound healing process.

Mechanism of Oleogel-S10: A triterpene preparation for the treatment of epidermolysis bullosa

Epidermolysis bullosa (EB) is a group of rare heterogeneous, genetic disorders. Currently, there is no effective pharmacological or genetic therapy for all EB subtypes. Dry extract from birch bark and betulin upregulate some pro‐inflammatory mediators and downregulate others. The increase in pro‐inflammatory cytokines is temporary and attenuated over long‐term treatment. This inflammatory stimulus is thought to be prerequisite for a secondary anti‐inflammatory response. Dry extract from birch bark and its active marker substances have also been shown to increase the migration of primary human keratinocytes, accelerate wound closure, and promote differentiation of keratinocytes in vitro and in vivo—processes that are essential for reepithelialization and maintenance of the skin barrier. Comprehensive clinical data are available to support the use of Oleogel‐S10 in the treatment of partial thickness wounds of different etiologies, and a proof‐of‐concept Phase 2 study in patients with dystrophic EB has suggested the potential for faster reepithelialization of wounds treated with Oleogel‐S10.

Oleogel-S10 Phase 3 study "EASE" for epidermolysis bullosa: study design and rationale

Background

Epidermolysis bullosa (EB) is a group of rare, genetic diseases that affect the integrity of epithelial tissues, most notably the skin. Patients experience recurrent skin wounding, with severity depending on type, sub-type, and mutation. Oleogel-S10, a formulation of birch bark extract, has demonstrated efficacy in a Phase 2 trial assessing re-epithelialization of wounds in EB. EASE (NCT03068780, EudraCT 2016–002066-32) is a randomized, Phase 3, placebo-controlled study designed to determine the efficacy of Oleogel-S10 versus placebo in patients with EB.

Methods

EASE is a Phase 3, two-phase study comprising a 90-day, double-blind, randomized, placebo-controlled phase, followed by 24 months of open-label, single-arm follow-up. Patients with junctional EB, dystrophic EB, or Kindler syndrome and target wounds (10 - 50cm²) present for > 21 days and < 9 months, are randomized in a 1:1 ratio to receive wound dressings according to local standard of care with or without Oleogel-S10. Placebo is based on the Oleogel-S10 vehicle, which is sunflower oil formulated to have a consistency indistinguishable from that of the active product. The primary endpoint of the trial, directed by the US health authority according to the required study endpoints for chronic cutaneous ulcer and burn wounds, is to compare the efficacy of Oleogel-S10 versus placebo according to the proportion of patients with complete closure of the target wound within 45 ± 7 days of treatment. Additional EB-focused endpoints include wound burden, patient-reported outcomes, and safety.

Results

Results of the primary endpoint are anticipated to be available by H2 2019.

Trial registration

ClinicalTrials.gov, NCT03068780. EudraCT, 2016–002066-32. Registered on 3 March 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3362-z) contains supplementary material, which is available to authorized users.

Efficacy of mycosynthesised AgNPs from Earliella scabrosa as an in vitro antibacterial and wound healing agent

The silver nanoparticles (AgNPs) with their unique chemical and physical properties are proving as a new therapeutical agent. In the present study, the AgNPs synthesised from an aqueous extract of a macrofungus, Earliella scabrosa, were characterised by field emission scanning electron microscopy (FESEM), energy dispersive X-ray analysis (EDX), high-resolution transmission electron microscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and further evaluate for its in vitro antibacterial and wound healing efficacy. The mycosynthesised AgNPs exhibited the surface plasmon resonance peak at 410 nm with good stability over a period of a month. The FESEM and EDX analyses revealed the spherical-shaped AgNPs of an average size of 20 nm and the presence of elemental Ag, respectively. The XRD pattern showed the crystalline nature of AgNPs. The FTIR spectra confirmed the conversion of Ag+ ions to AgNPs due to reduction by biomolecules of macrofungus extract. The mycosynthesised AgNPs showed effective antibacterial activity against two Gram-positive bacteria, namely Bacillus subtilis and Staphylococcus aureus, and two Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa. The pathogens were highly sensitive to AgNPs, whereas less sensitive to AgNO3. The mycosynthesised AgNPs showed significant wound healing potential with 68.58% of wound closure.

The discovery and development of topical medicines for wound healing

INTRODUCTION

Chronic, nonhealing skin wounds claim >3% of the health-care budget in industrialized countries, and the incidence is rising. Currently, two parallel trends influence innovations within the field of wound healing: the need to reduce spread of antibiotic resistance and the emerging use of health economy and value-based models. Areas covered: This review focuses on the discovery of drug candidates and development of treatments aiming to enhance wound healing in the heterogeneous group of patients with nonhealing wounds. Expert opinion: Nonhealing wounds are multifaceted and recognized as difficult indications. The majority of products currently in use are medical device dressings, or concepts of negative pressure or hyperbaric oxygen treatment. Global best practice guidelines for the treatment of diabetic foot ulcers recommend debridement, redressing, as well as infection control, and are critical to the lack of coherent clinical evidence for many approved products in active wound care. To accelerate wound healing, there is an emerging trend toward biologics, gene therapy, and novel concepts for drug delivery in research and in the pipeline for clinical trials. Scientific delineation of the therapeutic mechanism of action is, in our opinion, vital for clinical trial success and for an increased fraction of medical products in the pharmaceutical pipeline.