Accelerated reepithelialization by triterpenes: proof of concept in the healing of surgical skin lesions

Unlocking Therapeutic Potential: Comprehensive Extraction, Profiling, and Pharmacological Evaluation of Bioactive Compounds from Eclipta alba (L.) Hassk. for Dermatological Applications

Herbal medicine has been studied as an alternate approach to modern medicine as it is more cost-effective and accessible via natural sources. Eclipta alba (E. alba, L.) Hassk. is a weed plant abundantly distributed throughout different regions of the world and contains abundant bioactive compounds used for various skin conditions. In this review, we aimed to gather information from the literature about the extraction, separation, and identification of these bioactive compounds and their potential in skin diseases. Relevant studies published before August 2023 were identified and selected from electronic databases, including Scopus, SciFinder, ScienceDirect, Google Scholar, and Wiley Library, using the following keywords: Eclipta alba, Eclipta prostrata, phytochemicals, extraction, separation, isolation, identification, characterization, pharmacological activity, and skin conditions. Up-to-date extraction, separation, and identification methods of bioactive compounds from E. alba and their skin-related pharmacological activities are discussed in this review. As there are limitations regarding extraction, separation, and identification methods, and in-depth mechanistic and human studies of the skin-related pharmacological activities of bioactive compounds, these gaps are areas for future research to expand our understanding and broaden the potential applications of this medicinal weed plant, including the development of cosmeceutical and skincare products, anti-inflammatory agents, and formulations for dermatological treatments.

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.

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.

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.

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.

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).

Contributing to Global Health: Development of a Consensus-Based Whole Systems Research Strategy for Anthroposophic Medicine

Background

Whole medicine and health systems like traditional and complementary medicine systems (T&CM) are part of healthcare around the world. One key feature of T&CM is its focus on patient-centered and multimodal care and the integration of intercultural perspectives in a wide range of settings. It may contribute to good health and well being for people as part of the Sustainable Development Goals of the United Nations. The authentic, rigorous, and fair evaluation of such a medical system, with its inherent complexity and individualization, imposes methodological challenges. Hence, we propose a broad research strategy to test and characterize its possible contribution to health.

Methods

To develop a research strategy for a specific T&CM system, Anthroposophic Medicine (AM), applying multimodal integrative healthcare based on a four-level concept of man, we used a three-phase consensus process with experts and key stakeholders, consisting of (1) premeeting methodological literature and AM research review and interviews to supplement or revise items of the research strategy and tailor them to AM research, (2) face-to-face consensus meetings further developing and tailoring the strategy, and (3) postmeeting feedback and review, followed by finalization.

Results

Currently, AM covers many fields of medical specialties in varied levels of healthcare settings, such as outpatient and inpatient; primary, secondary, and tertiary care; and health education and pedagogy. It is by definition integrated with conventional medicine in the public healthcare system. It applies specific medicines, nursing techniques, arts therapies, eurythmy therapy, rhythmical massage, counseling, and psychotherapy, and it is provided by medical doctors, nurses, therapists, midwives, and nutritionists. A research strategy authentic to this level of complexity should comprise items with a focus on (I) efficacy and effectiveness, divided into (a) evaluation of the multimodal and multidisciplinary medical system as a whole, or of complex multimodal therapy concept, (b) a reasonable amount of methodologically rigorous, confirmatory randomized controlled trials on exemplary pharmacological and nonpharmacological therapies and indications, (c) a wide range of interventions and patient-centered care strategies with less extensive formats like well-conducted small trails, observational studies, and high-quality case reports and series, or subgroup analyses from whole-system studies, or health service research; (II) safety; (III) economics; (IV) evidence synthesis; (V) methodologic issues; (VI) biomedical, physiological, pharmacological, pharmaceutical, psychological, anthropological, and nosological issues as well as innovation and development; (VI) patient perspective and involvement, public needs, and ethics; (VII) educational matters and professionalism; and (IX) disease prevention, health promotion, and public health.

Conclusion

The research strategy extends to and complements the prevailing hierarchical system by introducing a broad “evidence house” approach to evaluation, something many health technology assessment boards today support. It may provide transparent and comprehensive insight into potential benefits or risks of AM. It can serve as a framework for an evidence-informed approach to AM for a variety of stakeholders and collaborating networks with the aim of improving global health.

Betulin wound gel accelerated healing of superficial partial thickness burns: Results of a randomized, intra-individually controlled, phase III trial with 12-months follow-up

OBJECTIVE

Acceleration of wound healing promises advantages for patients and caregivers in reducing the burden of disease, avoiding complications such as wound infections, and improving the long-term outcome. However, medicines that can accelerate wound healing are lacking. The objective of this open, blindly evaluated, randomized, multicenter phase III study was to compare intra-individually the efficacy and tolerability of Oleogel-S10 with fatty gauze dressing versus Octenilin^® wound gel with fatty gauze dressing in accelerating the healing of superficial partial thickness burn wounds.

METHODS

Acute superficial partial thickness burn wounds in adults caused by fire, heat burn or scalding were divided into 2 halves and randomly assigned to treatment with Oleogel-S10 or Octenilin^® wound gel. Photos for observer-blinded analysis of wound healing were taken at each wound dressing change. Percentages of reepithelialization were assessed at defined intervals. Efficacy and tolerability were evaluated based on a 5-point Likert scale.

RESULTS

Of 61 patients that were enrolled, 57 received the allocated intervention and 48 completed treatment. The percentage of patients with earlier wound healing was significantly higher for Oleogel-S10 (85.7%, n=30) compared to Octenilin^® wound gel (14.3%, n=5, p<0.0001). The mean intra-individual difference in time to wound closure was -1.0 day in favour of Oleogel-S10 (-1.4, -0.6; 95% CI, p<0.0001). Most investigators (87.0%) and patients (84.8%) evaluated the efficacy of Oleogel-S10 to be 'better' or 'much better' than that of Octenilin^® wound gel. Long-term outcome 3 months and 12 months post injury was improved in some patients.

CONCLUSIONS

Oleogel-S10 (Episalvan) significantly accelerated the healing of superficial partial thickness burn wounds. It was safe and well tolerated.

Betulin-Based Oleogel to Improve Wound Healing in Dystrophic Epidermolysis Bullosa: A Prospective Controlled Proof-of-Concept Study

Introduction

Skin fragility and recurrent wounds are hallmarks of hereditary epidermolysis bullosa (EB). Treatment options to accelerate wound healing are urgently needed. Oleogel-S10 contains a betulin-rich triterpene extract from birch bark. In this study, we tested the wound healing properties of topical Oleogel-S10 in patients with dystrophic EB.

Methods

We conducted an open, blindly evaluated, controlled, prospective phase II pilot trial in patients with dystrophic EB (EudraCT number 2010-019945-24). Healing of wounds treated with and without topical Oleogel-S10 was compared. Primary efficacy variable was faster reepithelialization as determined by 2 blinded experts. The main secondary outcome variable of the study was percentage of wound epithelialization.

Results

Twelve wound pairs of 10 patients with dystrophic EB were evaluated. In 5 of 12 cases, both blinded reviewers considered epithelialization of the intervention wounds as superior. In 3 cases, only one reviewer considered Oleogel-S10 as superior and the other one as equal to control. Measurements of wound size showed a trend towards accelerated wound healing with the intervention but without reaching statistical significance.

Conclusion

Our results indicate a potential for faster reepithelialization of wounds in patients with dystrophic EB when treated with Oleogel-S10 but larger studies are needed to confirm significance.

Comparison of In-Vitro and Ex-Vivo Wound Healing Assays for the Investigation of Diabetic Wound Healing and Demonstration of a Beneficial Effect of a Triterpene Extract

Diabetes mellitus is a frequent cause for chronic, difficult-to-treat wounds. New therapies for diabetic wounds are urgently needed and in-vitro or ex-vivo test systems are essential for the initial identification of new active molecules. The aim of this study is to compare in-vitro and ex-vivo test systems for their usability for early drug screening and to investigate the efficacy of a birch bark triterpene extract (TE) that has been proven ex-vivo and clinically to accelerate non-diabetic wound healing (WH), in a diabetic context. We investigated in-vitro models for diabetic WH, i.e. scratch assays with human keratinocytes from diabetic donors or cultured under hyperglycaemic conditions and a newly developed porcine ex-vivo hyperglycaemic WH model for their potential to mimic delayed diabetic WH and for the influence of TE in these test systems. We show that keratinocytes from diabetic donors often fail to exhibit significantly delayed WH. For cells under hyperglycaemic conditions significant decrease is observed but is influenced by choice of medium and presence of supplements. Also, donor age plays a role. Interestingly, hyperglycaemic effects are mainly hyperosmolaric effects in scratch assays. Ex-vivo models under hyperglycaemic conditions show a clear and substantial decrease of WH, and here both glucose and hyperosmolarity effects are involved. Finally, we provide evidence that TE is also beneficial for ex-vivo hyperglycaemic WH, resulting in significantly increased length of regenerated epidermis to 188±16% and 183±11% (SEM; p<0.05) compared to controls when using two different TE formulations. In conclusion, our results suggest that microenvironmental influences are important in WH test systems and that therefore the more complex hyperglycaemic ex-vivo model is more suitable for early drug screening. Limitations of the in-vitro and ex-vivo models are discussed. Furthermore our data recommend TE as a promising candidate for in-vivo testings in diabetic wounds.

Ex vivo Skin Permeation of Betulin from Water-in-Oil Foams

Triterpenes of the outer bark of birch are known to improve wound healing. An oleogel with these triterpenes as active principle is approved by the European Medicines Agency. As foams can be applied without touching the skin, they might be an advantageous application form. A comparable wound-healing effect can be expected when the permeation flux of the triterpenes from different types of formulations, namely oleogels, water-in-oil emulsions and water-in-oil foams, is similar. The tested formulations were based on three lipids (medium-chain trigylcerides, sunflower oil and paraffin) which differ in their polarity and solvent power for the triterpenes. Infinite dose permeation experiments were performed using porcine skin which was injured by either tape stripping or skin grafting. The results showed that steady-state permeation flux and lag time depend clearly on the depth of the skin lesion. Moreover, it was substantially affected by the lipid used as basis for the different formulations. In contrast, the different formulation types showed a comparable permeation behaviour leading to the conclusion that all formulation types can be used alike for the treatment of wounds, and the results that have already been obtained with oleogels can be directly translated to the foam with its superior use properties.

Triterpenes for Well-Balanced Scar Formation in Superficial Wounds

Triterpenes are demonstrably effective for accelerating re-epithelialisation of wounds and known to improve scar formation for superficial lesions. Among the variety of triterpenes, betuline is of particular medical interest. Topical betuline gel (TBG) received drug approval in 2016 from the European Commission as the first topical therapeutic agent with the proven clinical benefit of accelerating wound healing. Two self-conducted randomized intra-individual comparison clinical studies with a total of 220 patients involved in TBG treatment of skin graft surgical wounds have been screened for data concerning the aesthetic aspect of wound healing. Three months after surgery wound treatment with TBG resulted in about 30% of cases with more discreet scars, and standard of care in about 10%. Patients themselves appreciate the results of TBG after 3 months even more (about 50%) compared to standard of care (about 10%). One year after surgery, the superiority of TBG counts for about 25% in comparison with about 10%, and from the patients’ point of view, for 25% compared to 4% under standard of care. In the majority of wound treatment cases, there is no difference visible between TBG treatment and standard of care after 1 year of scar formation. However, in comparison, TBG still offers a better chance for discreet scars and therefore happens to be superior in good care of wounds.

Influence of the Oil Phase and Topical Formulation on the Wound Healing Ability of a Birch Bark Dry Extract

Triterpenes from the outer bark of birch are known for various pharmacological effects including enhanced wound healing (WH). A birch bark dry extract (TE) obtained by accelerated solvent extraction showed the ability to form oleogels when it is suspended in oils. Consistency of the oleogels and the dissolved amount of triterpenes varies largely with the used oil. Here we wanted to know to what extent different oils and formulations (oleogel versus o/w emulsion) influence WH. Looking at the plain oils, medium-chain triglycerides (MCT) enhanced WH (ca. 1.4-fold), while e.g. castor oil (ca.0.3-fold) or light liquid paraffin (LLP; ca. 0.5-fold) significantly decreased WH. Concerning the respective oleogels, TE-MCT showed no improvement although the solubility of the TE was high. In contrast, the oleogel of sunflower oil which alone showed a slight tendency to impair WH, enhanced WH significantly (ca. 1.6-fold). These results can be explained by release experiments where the release rate of betulin, the main component of TE, from MCT oleogels was significantly lower than from sunflower oil oleogels. LLP impaired WH as plain oil and even though it released betulin comparable to sunflower oil it still results in an overall negative effect of the oleogel on WH. As a further formulation option also surfactant free o/w emulsions were prepared using MCT, sunflower oil and LLP as a nonpolar oil phase. Depending on the preparation method (suspension or oleogel method) the distribution of the TE varied markedly and affected also release kinetics. However, the released betulin was clearly below the values measured with the respective oleogels. Consequently, none of the emulsions showed a significantly positive effect on WH. In conclusion, our data show that the oil used as a vehicle influences wound healing not only by affecting the release of the extract, but also by having its own vehicle effect on wound healing. This is also of importance for other applications where drugs have to be applied in non-polar vehicles because these solvents likely influence the outcome of the experiment substantially.

Influence of Birch Bark Triterpenes on Keratinocytes and Fibroblasts from Diabetic and Nondiabetic Donors

Impaired wound healing is one of the main risk factors associated with diabetes mellitus. Few options are available to treat diabetic wounds, and therefore efficient remedies are urgently needed. An interesting option might be an extract of birch bark (TE) that has been clinically proven to accelerate acute wound healing. We investigated the effects of TE and its main components betulin and lupeol in cultured normal keratinocytes and dermal fibroblasts from diabetic and nondiabetic donors. These in vitro models can provide insights into possible beneficial effects in wound healing. TE and betulin treatment led to increased mRNA levels of chemokines, pro-inflammatory cytokines, and mediators important in wound healing, e.g., IL-6, TNFα, IL-8, and RANTES. We observed a pronounced upregulation of MIF, IL-8, and RANTES on the protein level. Furthermore, a shape change of the actin cytoskeleton was seen in keratinocytes and fibroblasts, and the Rho-GTPases and p38-MAPK were found to be activated in keratinocytes. On the basis of our results, TE is worthy of further study as a potential option to influence wound-healing processes under diabetic conditions. These first insights need to be confirmed by clinical studies with diabetic patients.