The influence of essential oils on the process of wound healing: a review of the current evidence

Mechanistic Wound Healing of Ficus trijuja Leaf Extract and Its Lipid Nanocapsule Supported by Metabolomic Profiling and In Vivo Studies

This study explores the metabolic profile and wound-healing capabilities of Ficus trijuja, a species within the Moraceae family, for the first time. Ficus plants contain a variety of secondary metabolites such as flavonoids, triterpenoids, and alkaloids, known for their antioxidant, anti-inflammatory, and cytotoxic properties. Previous studies demonstrated the effectiveness of Ficus extracts in wound healing, with evidence of improved wound contraction, strength, and faster epithelization. This study shows the impact of F. trijuja extract in a gel base as well as when delivered through a lipid nanocapsules (LNCs) formula, on all phases of wound-healing in rats, by determining the expression levels of their key markers. The results indicated that treatment with F. trijuja extract accelerated wound healing, particularly when applied through lipid nanocapsulation, which shows comparable efficacy to standard treatments like MEBO® with approximately 2.62% improvement in wound healing when compared to MEBO® itself. Understanding these molecular markers offers insights for developing targeted therapies to optimize wound healing and prevent complication development. To unravel the phytochemical composition of F. trijuja extract, LC-HRESIMS analysis was implemented, which revealed 24 secondary metabolites belonging to different classes of flavonoids, terpenoids, and megastigmane. In conclusion, both Ficus trijuja gel and its nanoformulation have proven efficacy in wound healing in vivo and can be further investigated for potential clinical use.

Polymer-Based Wound Dressings Loaded with Essential Oil for the Treatment of Wounds: A Review

Wound healing can result in complex problems, and discovering an effective method to improve the healing process is essential. Polymeric biomaterials have structures similar to those identified in the extracellular matrix of the tissue to be regenerated and also avoid chronic inflammation, and immunological reactions. To obtain smart and effective dressings, bioactive agents, such as essential oils, are also used to promote a wide range of biological properties, which can accelerate the healing process. Therefore, we intend to explore advances in the potential for applying hybrid materials in wound healing. For this, fifty scientific articles dated from 2010 to 2023 were investigated using the Web of Science, Scopus, Science Direct, and PubMed databases. The principles of the healing process, use of polymers, type and properties of essential oils and processing techniques, and characteristics of dressings were identified. Thus, the plants Syzygium romanticum or Eugenia caryophyllata, Origanum vulgare, and Cinnamomum zeylanicum present prospects for application in clinical trials due to their proven effects on wound healing and reducing the incidence of inflammatory cells in the site of injury. The antimicrobial effect of essential oils is mainly due to polyphenols and terpenes such as eugenol, cinnamaldehyde, carvacrol, and thymol.

Multiplicative Effects of Essential Oils and Other Active Components on Skin Tissue and Skin Cancers

Naturally derived essential oils and their active components are known to possess various properties, ranging from anti-oxidant, anti-inflammatory, anti-bacterial, anti-fungal, and anti-cancer activities. Numerous types of essential oils and active components have been discovered, and their permissive roles have been addressed in various fields. In this comprehensive review, we focused on the roles of essential oils and active components in skin diseases and cancers as discovered over the past three decades. In particular, we opted to highlight the effectiveness of essential oils and their active components in developing strategies against various skin diseases and skin cancers and to describe the effects of the identified essential-oil-derived major components from physiological and pathological perspectives. Overall, this review provides a basis for the development of novel therapies for skin diseases and cancers, especially melanoma.

Essential Oils of Some Potential Medicinal Plants and their Wound Healing Activities

The wound has been recognised as a deep cut or tearing of the epidermis, which is also referred to as trauma and harm to the body tissues. Healing of wounds requires a coordinated series of cellular processes, including cell attraction, proliferation, differentiation, and angiogenesis. These processes involve interactions between various cells, such as macrophages, endothelial cells, keratinocytes, fibroblasts, growth hormones, and proteases. The outcome of wounds can be fatal if not treated properly, resulting in chronic wounds, chronic pain, and even death. Wound healing is replacing missing tissue with tissue repairs and regeneration. Some local variables are the presence of tissue maceration, foreign objects, biofilm, hypoxia, ischemia, and wound infection. Sustained growth factor delivery, siRNA delivery, micro-RNA targeting, and stem cell therapy are all emerging possible therapeutic approaches for wound healing. Traditional approaches, such as Ayurveda, Siddha, and Unani medicines, are also being used for treatment. The therapeutic application of nanoformulations in wound infections has shown various beneficial effects. Several herbal medicines, especially essential oils have shown potential wound healing activities, such as lavender, tea tree, sesame, olive, etc. Various nanoparticles and their nanoformulations have been explored in wound healing therapy. The present review article highlights several aspects of essential oils for wound healing activity through a novel drug delivery system. Further, some patents on wound healing through herbal medicine have been listed.

Biochemical and histological insights of 1,4-polyisoprene isolated from Sphenocentrum jollyanum pierre (menispermaceae) stem in wound healing activity in streptozotocin-induced diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Sphenocentrum jollyanum whole stem extract is used traditionally in combination with its leaves to treat chronic wounds and also ameliorate conditions that exacerbate wounds such as diabetes mellitus.

AIM OF THE STUDY

The study isolated the major wound healing bioactive compound from the non-polar fraction of S. jollyanum extract and evaluated the in vivo wound healing activity of a 0.10% w/w 1,4-polyisoprene-based ointment in streptozotocin-induced diabetic rats.

MATERIALS AND METHODS

The major bioactive constituent of S. jollyanum was isolated using a wound healing activity-guided approach and characterized the compound using 1D and 2D-NMR spectroscopic techniques. The wound healing activity study adopted both excision (wound contraction) and incision (biochemical) models.

RESULTS

In the excision model, the 1,4-polyisoprene caused 99% wound closure and restored the excised wound on day 12. On the 6th and 12th post-wounding days, 1,4-polyisoprene caused a significant (p < 0.001) elevation in the tensile strength (486 g) of the incision wound compared with the control (388 g). The biochemical (hexosamine and hydroxyproline) and antioxidant/inflammatory (ascorbic acid, superoxide dismutase, and glutathione peroxidase) parameters increased significantly while malondialdehyde was down-regulated in the wounds treated with 1,4-polyisoprene compared with control. The histological analysis of tissue sections taken from the edge and center of the wounds at 0-12 days post wounding revealed an increased tissue regeneration, accelerated collagen formation, and epidermal regeneration without edema or inflammation on the 12th day.

CONCLUSION

The major wound healing constituent of S. jollyanum is 1,4-polyisoprene and the study has provided a new class of compounds for further optimization.

Garlic and ginger essential oil-based neomycin nano-emulsions as effective and accelerated treatment for skin wounds' healing and inflammation: In-vivo and in-vitro studies

Skin, largest organ of human, is directly exposed to environment and hence is prone to high rates of injuries and microbial infections. Over the passage of time these microbes have developed resistance to antibiotics making them ineffective especially in lower doses and hence, higher dosages or new drugs are required. The current study deals with designing of nano-emulsion (NE) formulations composed of garlic and ginger oils (0.1 %) with neomycin sulphate used in different ratios (0.001, 0.01 and 0.1 %) and combinations. The resulting NEs were characterized for droplet size (145-304 nm), zetapotential (-3.0-0.9 mV), refractive index (1.331-1.344), viscosity (1.10-1.23cP), transmittance (96-99 %), FT-IR and HPLC and found stable over a period of three months. All NEs were also found effective against both gram positive and negative bacterial strains i.e., B. spizizenii, S. aureus, E. coli and S. enterica as compared to pure neomycin sulphate (NS) used as control with highest activity recorded for NE-2 and NE-4 against all strains showing zone of inhibition in range of 22-30 mm and 21-19 mm, respectively. NEs were also tested using rabbit skin excision wound model which potentiates that all the NEs resulted in early recovery with 86-100 % wound healing achieved in 9 days as compared to NS ointment (71 %). The studies confirmed that essential oils when used in combination with traditional drug can lead to much higher efficacies as compared to pure drugs.

Recent advances in metal-organic frameworks and their composites for the phototherapy of skin wounds

Wound healing is a complex process that greatly affects the normal physiological activities of genes, proteins, signaling pathways, tissues, and organs. Bacterial infection could easily lead to serious tissue damage during wound healing, thus countering wound infections becomes a major challenge for clinicians and nursing professionals. At present, the exploration of highly effective, low toxicity and environment friendly methods for wound healing is attracting considerable interest all over the world. Recently, metal-organic frameworks (MOFs) have presented great potential for treating wound infections due to their unique characteristics of diversified functionality, large specific surface area, and high biocompatibility. These properties endow MOFs/MOF-based composites with an outstanding anti-wound infection effect, which is mainly attributed to the continuously released active components and the exerted catalytic activity with the assistance of phototherapy. In this review, the current progress of MOFs/MOF-based composites for the phototherapy of skin wounds is presented. Firstly, we illustrate the pathophysiological mechanisms, principles of phototherapy and the conventional methods for wound healing. Then, the structures and characteristics of MOFs are systematically summarized. Moreover, the review highlights the recent advances in the application of phototherapy for wound healing (including photodynamic therapy, photothermal therapy, and synergistic therapy) based on various MOFs/MOF-based composites. Finally, the challenges and perspectives are provided for the further development of MOF-based materials for medical application.

Medicinal Herbs from Phyto-informatics: An aid for Skin Burn Management

Skin burn injury is the most common cause of trauma that is still considered a dreadful condition in healthcare emergencies around the globe. Due to the availability of a variety of regimes, their management remains a dynamical challenge for the entire medical and paramedical community. Indeed, skin burn injuries are accompanied by a series of several devastating events that lead to sepsis and multiple organ dysfunction syndromes. Hence the challenge lies in to develop better understanding as well as clear diagnostic criteria and predictive biomarkers which are important in their management. Though there are several regimes available in the market, there are still numerous limitations and challenges in the management. In this review article, we have discussed the various biomarkers that could be targeted for managing skin burn injuries. Instead of focusing on allopathic medication which has its adverse events per se, we have discussed the history, ethnopharmacology properties, and prospects of identified phytomedicines from a well-established herbal informatics model. This review article not only discusses the benefits of scrutinized phytocompounds but also leads to develop novel druggable Phyto-compounds to target skin burn injury at lower cost with no adverse effects.

Therapy of infected wounds: overcoming clinical challenges by advanced drug delivery systems

In recent years, the incidence of infected wounds is steadily increasing, and so is the clinical as well as economic interest in effective therapies. These combine reduction of pathogen load in the wound with general wound management to facilitate the healing process. The success of current therapies is challenged by harsh conditions in the wound microenvironment, chronicity, and biofilm formation, thus impeding adequate concentrations of active antimicrobials at the site of infection. Inadequate dosing accuracy of systemically and topically applied antibiotics is prone to promote development of antibiotic resistance, while in the case of antiseptics, cytotoxicity is a major problem. Advanced drug delivery systems have the potential to enable the tailor-made application of antimicrobials to the side of action, resulting in an effective treatment with negligible side effects. This review provides a comprehensive overview of the current state of treatment options for the therapy of infected wounds. In this context, a special focus is set on delivery systems for antimicrobials ranging from semi-solid and liquid formulations over wound dressings to more advanced carriers such as nano-sized particulate systems, vesicular systems, electrospun fibers, and microneedles, which are discussed regarding their potential for effective therapy of wound infections. Further, established and novel models and analytical techniques for preclinical testing are introduced and a future perspective is provided.

The Effects of Lavender Essential Oil on Wound Healing: A Review of the Current Evidence

Background: The commercialization of essential oils has expanded their presence in the United States, and emerging studies demonstrate that they may have a place in Western medicine. One oil with a significant body of evidence is lavender essential oil, which may have benefits in wound healing. Objectives: This review aims to present the scientific literature on therapeutic lavender essential oil with the goal of expanding the current repertoire of cost-effective wound healing options available to physicians and patients. Methods: A review was conducted according to PRISMA guidelines in PubMed, Cochrane Library, and Embase from June 2018 through March 2019 to identify articles related to lavender essential oil in the context of wound healing. Results: This search yielded 36 unique studies, 20 of which remained after screening. This review utilizes human clinical trials (n = 7), animal trials (n = 5), in vitro studies (n = 2), and previously conducted reviews (n = 6). Overall, these studies demonstrated a faster rate of wound healing, increased expression of collagen, and enhanced activity of proteins involved in the tissue remodeling process in wounds treated with lavender essential oil. Conclusions: The current body of literature suggests a potential therapeutic benefit of lavender essential oil in wound healing. However, standardization of the chemical composition and additional high-quality human clinical trials are needed to further evaluate the safety and efficacy of lavender essential oil in clinical practice.

Appraisal on the wound healing potential of Melaleuca alternifolia and Rosmarinus officinalis L. essential oil-loaded chitosan topical preparations

The present study investigates the wound healing potential of three chitosan-based topical preparations loaded with either tea tree essential oil, rosemary essential oil or a mixture of both oils in vivo. Essential oils of M. alternifolia and R. officinalis were analyzed using GC/MS. Essential oil-loaded chitosan topical preparations were formulated. Wound healing potential was evaluated in vivo using an excision wound model in rats. GC/MS analysis of M. alternifolia and R. officinalis essential oils revealed richness in oxygenated monoterpenes, representing 51.06% and 69.61% of the total oil composition, respectively. Topical application of chitosan-based formulation loaded with a mixture of tea tree and rosemary oils resulted in a significant increase in wound contraction percentage compared to either group treated with individual essential oils and the untreated group. Histopathological examination revealed that topical application of tea tree and rosemary oil combination demonstrated complete re-epithelialization associated with activated hair follicles. The high percentage of oxygenated monoterpenes in both essential oils play an important role in the antioxidant and wound healing potential observed herein. Incorporation of tea tree and rosemary essential oils in chitosan-based preparations in appropriate combination could efficiently promote different stages of wound healing.

Influence of lavender oil inhalation on vital signs and anxiety: A randomized clinical trial

OBJECTIVE

To investigate the effectiveness of lavender oil (Lavandula angustifolia Mill) inhalation on anxiety, mood, and vital signs (blood pressure, respiratory rate, heart rate, and saturation) of patients undergoing oral surgery. Vital signs were considered as primary outcome measures. Paired anxiety tests were used as secondary outcome measures.

METHODS

Patients who had dental anxiety according to the Dental Anxiety Questionnaire (DAQ) were enrolled in the study. One hundred twenty-six patients who were undergoing wisdom tooth removal under local anaesthesia were randomly assigned to the lavender oil and control groups. Paired anxiety tests (Modified Dental Anxiety Scale and State-Trait Anxiety Inventory-State Scale were performed. Vital signs were noted pre-, intra-, and post-operatively. Visual analogue scale (VAS) results were assessed. The patients' degree of satisfaction was noted.

RESULTS

Pre-operative anxiety levels were similar in both groups. Significant changes in blood pressure were observed in the lavender oil group post-operatively (p < .05). Most (79.4%) of the patients in the lavender oil group enjoyed the scent, 89.68% were satisfied with their experience, and 97.62% of the patients stated that they would prefer the same protocol when needed.

CONCLUSION

Inhalation of lavender oil, which is one of the most powerful anxiolytic essential oils, reduces peri-operative anxiety and can be prospectively considered in future studies for its potential sedative characteristics in patients undergoing surgical procedures under local anaesthesia.

TRIAL REGISTRATION NUMBER

NCT03722771 (Influence of Lavender Oil on Vital Signs in Oral Surgery Patients) https://clinicaltrials.gov/ct2/show/NCT03722771.

Tunisian Clematis flammula Essential Oil Enhances Wound Healing: GC-MS Analysis, Biochemical and Histological Assessment

The aerial part of Clematis flammula (Ranunculaceae) has been traditionally used in the treatment of skin diseases including mycotic infection in the Tunisian traditional medicine. The study was undertaken to extract and determine the essential oil chemical composition of Clematis flammula aerial parts and to assess the potential of anemonin in wound healing on mechanically wounded wistar rats. The essential oil was obtained by hydrodistillation and analyzed by GC-MS. Anemonin was isolated and then incorporated as active in a cream for which the cytotoxicity was evaluated by methyl thiazolyl tetrazolium (MTT)-based colorimetric assay. Then, its potential in wound healing on mechanically wounded wistar rats was assessed. The GC-MS analysis showed that the major compound was protoanemonin (86.74%) which spontaneously dimerised in part to form the anemonin. The wound healing activity of anemonin cream exhibited a non toxic potential of anemonin at a concentration of 25 µg/mL with a cell migration efficiency that reaches more than 80% after 48 hours of treatment. Wound healing efficiency was evaluated by monitoring morphological and skin histological analyses. Comparable wound surface reduction of the group treated by anemonin cream (p ≥ 0.05) when compared to the reference treated group. The skin histological analysis showed the completely wound closure. Antioxidant activity was assessed by the malondialdehyde (MDA) rates and antioxidant enzymes (glutathione peroxidase (GPx) and catalase) determination. The results provided strong support for the effective wound healing activity of anemonin cream, making it a promising candidate as a therapeutic agent in tissue repairing processes.

Cytotoxicity and antimicrobial action of selected phytochemicals against planktonic and sessile Streptococcus mutans

Background

Dental caries remains the most prevalent and costly oral infectious disease worldwide, encouraging the search for new and more effective antimicrobials. Therefore, the aim of this work was to study the antimicrobial action of selected phytochemicals (eugenol, citronellol, sabinene hydrate, trans-cinnamaldehyde, terpineol and cinnamic acid) against Streptococcus mutans in planktonic and biofilm states as well as the cytotoxicity of these compounds.

Methods

The antibacterial activity of the selected compounds was evaluated by the determination of the minimal bactericidal concentration. The resazurin assay was used to assess the metabolic activity of sessile S. mutans. The cytotoxicity was determined using a fibroblast cell line.

Results

Among the tested phytochemicals, citronellol, cinnamic acid and trans-cinnamaldehyde were the most effective against both planktonic and sessile S. mutans, an effect apparently related to their hydrophobic character. Additionally, these three compounds did not compromise fibroblasts cell viability.

Discussion

Citronellol, cinnamic acid and trans-cinnamaldehyde demonstrated significant antimicrobial activity and low cytotoxicity proposing their potential as a novel group of therapeutic compounds to control oral infectious diseases. Moreover, their effects are particularly relevant when benchmarked against eugenol, a phytochemical commonly used for prosthodontic applications in dentistry.

Tea tree oil presents in vitro antitumor activity on breast cancer cells without cytotoxic effects on fibroblasts and on peripheral blood mononuclear cells

The purpose of this study was to investigate some possible mechanisms underlying the in vitro antitumor activity of tea tree oil (TTO) on human and mouse breast cancer cells (MCF-7 and 4T1, respectively) and its cytotoxicity on fibroblasts (HFF-1) and on peripheral blood mononuclear cells (PBMCs). TTO High-Resolution Gas Chromatography (HRGC) showed seventeen main constituents, such as Terpinen-4-ol, γ-Terpinene, and α-Terpinene. High TTO concentrations (≥ 600 μg/mL) showed a remarkable antitumor activity, decreasing cell viability and cell proliferation of MCF-7 and 4T1 cells. TTO at 300 μg/mL increased the number of MCF-7 cells in the early stages of apoptosis and increased the BAX/BCL-2 genes ratio. TTO, mainly at 300 μg/mL, decreased cell growth and arrested MCF-7 cells in the S phase of the cell cycle. Lower antitumor concentrations (≤300 μg/mL) evaluated in MCF-7 and 4T1 cells were not cytotoxic to PBMCs and HFF-1. Also, TTO (300 μg/mL) was able to induce cell proliferation in fibroblasts after 72 h, indicating non-cytotoxic effect in these cells. TTO exhibited in vitro antitumor effect on MCF-7 and 4T1 cells by decreasing cell viability and modulating apoptotic pathways and cell cycle arrestment of MCF-7 cells. In this sense, our study provides new perspectives on the potential use of TTO for the development of new alternative therapies to treat topically locally advanced breast cancer (LABC).

Microbiota of Chronic Diabetic Wounds: Ecology, Impact, and Potential for Innovative Treatment Strategies

World Health Organization considered diabetes as one of the 20th century epidemics, estimating that over 10% of the world population is diabetic or at high risk. Self-assessment studies indicate that diabetic patients consider chronic wounds to affect their quality of life more dramatically than vision loss or renal failure. In addition to being the main reason for diabetic patients' hospitalization, the economic burden of diabetic chronic wounds is close to 1% of United Kingdom and United States health systems budgets, which exceeds the funds allocated to the treatment of some types of cancer in both countries. Among the factors preceding the emergence of chronic diabetic wounds, also designated diabetic foot ulcers (DFUs), hygiene and pressure in specific areas are under patient control, while others are still far from being understood. A triple impairment in the innervation, immune responses, and vascularization associated to DFU has been extensively studied by the scientific community. However, the skin natural microbiota has only recently emerged as having a tremendous impact on DFU emergence and evolution to chronicity. Despite the great inter- and intra-variability of microbial colonizers, ongoing efforts are now focused on deciphering the impact of commensal and pathogenic microbiota on DFU etiology, as well as the mechanisms of interkingdom microbial-host communication. This review summarizes recent work in this context and offers new microbiological perspectives that may hold potential in the prevention and treatment of chronic diabetic wounds.

Randomized, controlled study of innovative spray formulation containing ozonated oil and α-bisabolol in the topical treatment of chronic venous leg ulcers

OBJECTIVE

Ozone therapy has a large clinical application in many therapeutic areas because of its well-known antimicrobial, immunological, and oxygenating properties. Recently, interest has grown regarding the application of ozonated oil for vascular leg ulcer treatment. The efficacy of an innovative spray formulation of ozonated oil and α-bisabolol combination in the topical treatment of chronic venous leg ulcers was evaluated compared with standard epithelialization cream.

DESIGN

A randomized controlled trial was conducted.

SETTING

A total of 29 patients older than 18 years with chronic venous leg ulcers for less than 2 years' duration were assessed.

PATIENTS

Patients were randomized to receive daily application of both ozonated oil and α-bisabolol or the control cream (vitamin A, vitamin E, talc, and zinc oxide) for 30 days.

MAIN OUTCOME MEASURES

Patients were evaluated on 4 different visits: at days 0, 7, 14, and 30. At each visit, the wound surfaces were measured. Wound area ratio and the speed of ulcer healing were calculated.

MAIN RESULTS

At the end of treatment, the proportion of patients with complete ulcer healing was higher with ozonated oil and α-bisabolol formulation (25% vs 0%). Furthermore, the changes in ulcer surface area were significant for ozonated oil and α-bisabolol formulation only (P < .05), in particular, observing a significant and progressive reduction of the wound surface by 34%, 59%, and 73%, after 7, 14, and 30 days of treatment, respectively.

CONCLUSION

The innovative spray formulation of ozonated oil and α-bisabolol combination shows promise as an important new therapeutic option in the adjuvant treatment of venous ulcers.

Efficacy of Trans-cinnamaldehyde and Eugenol in Reducing Acinetobacter baumannii Adhesion to and Invasion of Human Keratinocytes and Controlling Wound Infection In Vitro

The study investigated the efficacy of two natural, plant-derived antimicrobials (PDAs), namely trans-cinnamaldehyde (TC), and eugenol (EG) for decreasing Acinetobacter baumannii adhesion to and invasion of human keratinocytes (HEK001). Moreover, the efficacy of two PDAs for inhibiting A. baumannii biofilm formation was determined using an in vitro collagen matrix wound model. Additionally, the effect of TC and EG on A. baumannii biofilm architecture was visualized using confocal scanning microscopy. Further the effect of both PDAs on genes critical for biofilm synthesis was determined using real-time quantitative polymerase chain reaction. Both TC and EG significantly reduced A. baumannii adhesion and invasion to HEK001 by ~2 to 3 log₁₀ CFU/mL (p < 0.05) compared with the controls (p < 0.05). Further, after 24 and 48 h, TC and EG inhibited biofilm formation by ~1.5 to 2 and ~2 to 3.5 log₁₀ CFU/mL, compared with controls (p < 0.05). Confocal microscopy revealed that TC and EG disrupted the biofilm architecture. RT-qPCR results indicated that two phytochemicals significantly down-regulated the transcription of genes associated with A. baumannii biofilm production. The results suggest that both TC and EG could potentially be used to treat A. baumannii wound infections; however, their efficacy in in vivo models needs to be validated. Copyright © 2016 John Wiley & Sons, Ltd.

Wound healing potential of lavender oil by acceleration of granulation and wound contraction through induction of TGF-β in a rat model

Background

Although previous studies have suggested that lavender oil promote wound healing, no study has examined the molecular mechanisms of its effect. In this study, we investigated the effect of lavender oil on various steps of wound healing and its molecular mechanism, focusing on transforming growth factor-β (TGF-β).

Methods

Circular full-thickness skin wounds were produced on rats. Control solution or lavender oil was topically applied to the wounds on alternating days for 14 days.

Results

The area of wounds topically treated with lavender oil was significantly decreased as compared to that of wounds of control rats at 4, 6, 8, and 10 days after wounding. Topical application of lavender oil induced expression of type I and III collagen at 4 days after wounding, accompanied by an increased number of fibroblasts, which synthesize collagen. Induced expression of type III collagen by topical application of lavender oil was reduced to control level at 7 days after wounding although increased expression of type I collagen still continued even at 7 days, suggesting rapid collagen replacement from type III to type I in wounds treated with lavender oil. Importantly, expression of TGF-β in wounds treated with lavender oil was significantly increased as compared to control. Moreover, an increased number of myofibroblasts was observed in wounds treated with lavender oil at 4 days after wounding, suggesting promotion of differentiation of fibroblasts through induction of TGF-β, which is needed for wound contraction.

Conclusion

This study demonstrated that topical application of lavender oil promoted collagen synthesis and differentiation of fibroblasts, accompanied by up-regulation of TGF-β. These data suggest that lavender oil has the potential to promote wound healing in the early phase by acceleration of formation of granulation tissue, tissue remodeling by collagen replacement and wound contraction through up-regulation of TGF-β. The beneficial effect of lavender oil on wound healing may raise the possibility of new approaches as complementary treatment besides conventional therapy.

In vitro activity of Melaleuca alternifolia (tea tree) oil on filamentous fungi and toxicity to human cells

Invasive fungal wound infections (IFIs) are increasingly reported in trauma patients and cause considerable morbidity and mortality despite standard of care treatment in trauma centers by experienced medical personnel. Topical agents such as oil of melaleuca, also known as tea tree oil (TTO), have been proposed for adjunctive treatment of IFIs. We evaluated the activity of TTO against filamentous fungi associated with IFIs by testing 13 clinical isolates representing nine species via time-kill assay with seven concentrations of TTO (100%, 75%, 50%, 25%, 10%, 5%, and 1%). To ascertain the safety of topical application to wounds, cell viability assays were performed in vitro using human fibroblasts, keratinocytes, osteoblasts, and umbilical vein endothelial cells with 10 concentrations of TTO (75%, 50%, 25%, 10%, 5%, and 10-fold serial dilutions from 1 to 0.0001%) at five time points (5, 15, 30, 60, and 180 min). Compatibility of TTO with explanted porcine tissues was also assessed with eight concentrations of TTO (100%, 75%, 50%, 25%, 10%, 5%, 1%, and 0.1%) at the time points used for cellular assays and at 24 h. The time-kill studies showed that fungicidal activity was variable between isolates. The effect of TTO on cell viability was primarily concentration dependent with significant cytotoxicity at concentrations of ≥ 10% and ≥ 50% for cells lines and whole tissue, respectively. Our findings demonstrate that TTO possesses antifungal activity against filamentous fungi associated with IFIs; furthermore that negligible effects on whole tissues, in contrast to individual cells, were observed following exposure to TTO. Collectively, these findings indicate a potential use of TTO as topical treatment of IFIs.

Essential oils and their constituents as skin penetration enhancer for transdermal drug delivery: a review

OBJECTIVES

In this paper, we focused on essential oils and their constituents as skin penetration enhancers for transdermal drug delivery, mechanism of their action as well as their possible toxicity.

KEY FINDINGS

Essential oils and their volatile constituents can penetrate through the skin as well as enhance penetration of different drug from topical formulation into the lower skin layers using different mechanisms of action based on (1) disintegration of the highly ordered intercellular lipid structure between corneocytes in stratum corneum, (2) interaction with intercellular domain of protein, which induces their conformational modification, (3) increase the partitioning of a drug. After application to the skin, essential oils and their components are rapidly metabolized, not accumulated in the organism and fast excreted what strongly suggest that they can be successfully use as safe penetration enhancers.

SUMMARY

Essential oils and their constituents may be preferred over the traditionally used synthetics materials as safe and suitable permeation enhancers to promote the percutaneous absorption of hydrophilic and lipophilic drugs from topical formulation into the lower skin layers.

Plant essential oils and their constituents in coping with multidrug-resistant bacteria

Antibiotic resistance is documented to be a serious problem that affects the choice of appropriate antibiotic therapy and increases the probability of unfavorable infection outcome. One of the proposed methods to cope with multidrug-resistant (MDR) bacteria is the use of alternative antibacterial treatments, which include natural antimicrobial substances such as plant essential oils (EOs). The aim of the present article is to review published studies on the activity of EOs and their constituents against MDR bacteria and to formulate perspectives for the future. In general, published studies indicate that EOs can be used as effective antiseptics against many species, including MDR bacteria, such as methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, resistant isolates of Pseudomonas aeruginosa, Klebsiella pneumoniae and others; certain EOs may potentiate the effectiveness of antibiotics against MDR bacteria; EOs can be synergistic with bacteriophages; and polymeric nanoparticles can be used for delivery of EOs and enhancement of their activity at the site of infection.

Suppression of allergic and inflammatory responses by essential oils derived from herbal plants and citrus fruits

The aim of the present study was to investigate the biological activity of 20 essential oils (EOs) derived from herbal plants and citrus fruits. The in vitro anti-allergic and anti-inflammatory activities of these oils were investigated, and the EO which was found to have the strongest activity of the 20 EOs examined, was investigated further to identify its components and bioactive compounds. The in vitro anti-allergic activity was determined by measuring the release of β-hexosaminidase from rat basophilic leukemia (RBL-2H3) cells treated with the calcium ionophore, A23187. The in vitro anti-inflammatory activity was determined by measuring the production of tumor necrosis factor-α (TNF-α) in RAW264.7 murine macrophages treated with lipopolysaccharide. Among the EOs examined, lemongrass [Cymbopogon citratus (DC.) Stapf] elicited the strongest anti-allergic and anti-inflammatory effects. A principal component of this EO is citral (3,7-dimethyl-2,6-octadien-1-al) (74.5%), a mixture of the stereoisomers, geranial (trans-citral, 40.16%) and neral (cis-citral, 34.24%), as determined by chromatography-mass spectrometry analysis. The activities of citral and geranial are similar to those of lemongrass EO. These compounds elicited significant in vivo anti-allergic and anti-inflammatory effects, suppressing an immunoglobulin E (IgE)-induced passive cutaneous anaphylactic reaction in mice and a 12-O-tetradecanoylphorbol-13-acetate-induced inflammatory mouse ear edema, respectively. Our data demonstrate that lemongrass EO and its constituents, citral and geranial, may be a therapeutic candidate for allergic and inflammatory diseases.

Effect of an Essential Oil Mixture on Skin Reactions in Women Undergoing Radiotherapy for Breast Cancer

Purpose:This pilot study compared the effects of an essential oil mixture versus standard care on skin reactions in breast cancer patients receiving radiation. Method: Using an experimental design, 24 patients were randomized to standard care (i.e., RadiaPlexRx™ ointment) or an essential oil mixture. Products were applied topically three times a day until 1 month postradiation. Weekly skin assessments were recorded and women completed patient satisfaction and quality of life (QOL) instruments at 3-, 6-, and 10-week intervals. Results: No significant differences were found for skin, QOL, or patient satisfaction at interim or follow-up time points. Effect sizes were as follows: skin = .01 to .07 (small-medium effect); QOL = .01 to .04 (small effect); patient satisfaction = .02 (small effect). Conclusion: The essential oil mixture did not provide a better skin protectant effect than standard care. These findings suggest the essential oil mixture is equivalent to RadiaPlexRx, a common product used as standard care since it has been shown to be effective in protecting skin from radiation. Thus, this pilot provides evidence to support botanical or nonpharmaceutical options for women during radiotherapy for breast cancer.

Anti-inflammatory activity of essential oils from Syzygium cumini and Psidium guajava

CONTEXT

Despite the many biological activities reported for essential oils, their anti-inflammatory ability is relatively underexplored considering the wide variation in plant sources and in their volatile composition. Oils from Syzygium cumini Skells (SC) and Psidium guajava L. (PG) (Myrtaceae) have been described as having diverse pharmacological activities.

OBJECTIVE

The current study seeks to evaluate the anti-inflammatory activity of the essential oils from the leaves of SC and PG, as well as some of their terpene-enriched fractions (+V = more volatile and -V = less volatile) obtained by vacuum distillation. Both the pharmacological responses and chemical compositions were correlated.

MATERIALS AND METHODS

The relative contents of the oils and their fractions were evaluated by gas chromatography. Individual constituents in the oils were characterized by gas chromatography coupled to mass spectrometry. Anti-inflammatory activity was accessed in the lipopolysaccharide-induced pleurisy model, by measuring the inhibition of total leukocyte, neutrophil and eosinophil migration in the mice pleural lavage, after oil treatment with the oils at 100 mg/kg.

RESULTS

Eosinophil migration was inhibited by SC (67%), SC (+V) (63%), PG (76%), PG (+V) (67%) and PG (-V) (74%). This efficacy was correlated with the presence of β-pinene and β-caryophyllene in the oils, a result that was reinforced by evaluating both these pure components (38 and 50% inhibition, respectively). Synergistic effects associated with the presence of α-pinene were speculated.

DISCUSSION AND CONCLUSION

Essential oils from SC and PG may be useful to treat inflammatory diseases by mechanisms that include the inhibition of eosinophil migration.

Evaluation of anti-bacterial and wound healing activity of the fruits of Amorpha fruticosa L

As the traditional Chinese medicine, the fresh fruits of Amorpha fruticosa L. were applied for the treatment of carbuncle, eczema and burn (Das et al., 2007). However, little is known about the functional roles of the fruits of Amorpha fruticosa L. during wound healing progress. In the present study, we evaluated both antimicrobial potential against a wide range of microorganisms and wound healing activity of the seven compounds isolated from the fruits of Amorpha fruticosa L in vitro and in vivo. Our results showed that compounds I (6a,12a-dehydroamorphin), V (dehydrosermundone) and VI (tephrosin) isolated from the fruits of Amorpha fruticosa L. performed dominant antimicrobial potential against microorganisms. Moreover, these compounds significantly enhanced fibroblasts proliferation and migration, leading to promotion of wound healing. Thus, it could be possible for the therapeutic utilization of Amorpha fruticosa L. for wound healing in the future.

Effects of essential oils from herbal plants and citrus fruits on DNA polymerase inhibitory, cancer cell growth inhibitory, antiallergic, and antioxidant activities

In this study, the biological activity of 20 essential oils (EOs) from herbal plants and citrus fruits were investigated in terms of mammalian DNA polymerase (pol) inhibitory activity, cancer cell (human colon carcinoma, HCT116) growth inhibitory activity, antiallergic activity, as anti-β-hexosaminidase release activity in rat basophilic leukemia RBL-2H3 cells treated with calcium ionophore A23187, and antioxidant activity by a lipophilic-oxygen radical absorbance capacity method. These EOs showed patterns of inhibition of pol α, a DNA replicative pol, similar to their cancer cell growth inhibitory activity, and their inhibitory activity on pol λ, a DNA repair/recombination pol, by the EOs showed correlation with anti-β-hexosaminidase release activity. Among these EOs, chamomile (Matricaria chamomilla L.) was the strongest inhibitor of pols α and λ and showed significant effects on both cancer cell growth and mast cell degranulation. On the basis of these results, chamomile EO can be recommended as a potentially useful, bioactive candidate for therapeutic applications.

Activity of tea tree oil and nerolidol alone or in combination against Pediculus capitis (head lice) and its eggs

Head lice infestation is an emerging social problem in undeveloped and developed countries. Because of louse resistance increasing, several long-used insecticidal compounds have lost their efficacy, and alternatives, such as essential oils, have been proposed to treat this parasitic infestation. The present study investigated the efficacy of two natural substances: tea tree (Melaleuca alternifolia) oil and nerolidol (3,7,11-trimethyl-1,6,10-dodecatrien-3-ol) against lice and its eggs. Products were used alone and in combination (ratio 1:1 and 1:2) from 8 % dilution. The in vitro effect of natural substances at different concentrations were evaluated against 69 head lice (adults and nymphs) and 187 louse eggs collected from school children in Chieti-Pescara (Central Italy) over a 6-month period. The lice mortality was evaluated for 24 h by a stereo light microscope. The ovicidal activity was monitored by microscopic inspections for 15 days. Tea tree oil was more effective than nerolidol against head lice with 100 % mortality at 30 min and 1 % concentration. On the contrary, nerolidol expressed a more pronounced ovicidal activity inducing the failure of 50 % of the eggs to hatch at 1 % concentration after 4 days; the same effect was achieved by using a twice concentration of tea tree oil. The association of the two substances both in ratios 1:1 and 1:2 combined efficaciously their insecticidal and ovicidal effect; in particular, the ratio 1:2 (tea tree oil 0.5 % plus nerolidol 1 %) acted producing both the death of all head lice at 30 min and the abortive effect of louse eggs after 5 days. These results offer new potential application of natural compounds and display a promising scenario in the treatment of pediculosis resistant cases. The development of novel pediculicides containing essential oils could be, in fact, an important tool to control the parasitic infestation.

Natural alternatives to in-feed antibiotics in pig production: can immunomodulators play a role?

As a result of the European ban of in-feed growth-promoting antibiotics, new strategies are being developed to increase the resistance to disease in farm animals. In pig production, this is of particular importance during the weaning transition when piglets are subjected to major stressful events, making them highly sensitive to digestive disorders. At this time, the development of both innate and adaptive immunity at the mucosal surface is critical in preventing the potential harmful effects of intestinal pathogenic agents. Strategies aiming at stimulating natural host defences through the use of substances able to modulate immune functions have gained increasing interest in animal research, and different bioactive components a priori sharing those properties have been the subject of in vivo nutritional investigations in pig. Among these, yeast derivates (β-glucans and mannans) are able to interact with immune cells, particularly phagocytic cells. However, studies where they have been fed to pigs have shown inconsistent results, suggesting that their ability to target the sensitive immune cells through the oral route is questionable. The plant extracts, which would benefit from a positive image in the public opinion, have also been tested. However, due to a lack of data on the bioactive components of particular plants and the large diversity of species, it has proved difficult to prepare extracts of equivalent potency and thus, the literature on their influence on pig immunity remains inconclusive. In considering piglet immunity and health benefits, the most promising results to date have been obtained with spray-dried animal plasma, whose positive effects would be provided by specific antibodies and non-specific competition of some plasma components with bacteria for intestinal receptors. The major positive effect of spray-dried animal plasma is in reducing the infiltration of gut-associated lymphoid tissue by immune cells, which is likely to be the result of a decreased colonisation by potentially harmful bacteria. This review also highlights the limitations of some of the published in vivo studies on the immunomodulatory activity of certain feed additives. Among those, the lack of standardisation of extracts and the heterogeneity of piglet-rearing conditions (e.g. exposure to pathogens) are likely the most limiting.

A review of applications of tea tree oil in dermatology

Tea tree oil (TTO) is an essential oil, steam-distilled from the Australian native plant, Melaleuca alternifolia. It has a minimum content of terpinen-4-ol and a maximum content of 1, 8-cineole. Terpinen-4-ol is a major TTO component which exhibits strong antimicrobial and anti-inflammatory properties. Tea tree oil exerts antioxidant activity and has been reported to have broad-spectrum antimicrobial activity against bacterial, viral, fungal, and protozoal infections affecting skin and mucosa. Several studies have suggested the uses of TTO for the treatment of acne vulgaris, seborrheic dermatitis, and chronic gingivitis. It also accelerates the wound healing process and exhibits anti-skin cancer activity. This review opens up new horizons for dermatologists in the use of this herbal agent.

Coping with antibiotic resistance: combining nanoparticles with antibiotics and other antimicrobial agents

The worldwide escalation of bacterial resistance to conventional medical antibiotics is a serious concern for modern medicine. High prevalence of multidrug-resistant bacteria among bacteria-based infections decreases effectiveness of current treatments and causes thousands of deaths. New improvements in present methods and novel strategies are urgently needed to cope with this problem. Owing to their antibacterial activities, metallic nanoparticles represent an effective solution for overcoming bacterial resistance. However, metallic nanoparticles are toxic, which causes restrictions in their use. Recent studies have shown that combining nanoparticles with antibiotics not only reduces the toxicity of both agents towards human cells by decreasing the requirement for high dosages but also enhances their bactericidal properties. Combining antibiotics with nanoparticles also restores their ability to destroy bacteria that have acquired resistance to them. Furthermore, nanoparticles tagged with antibiotics have been shown to increase the concentration of antibiotics at the site of bacterium-antibiotic interaction, and to facilitate binding of antibiotics to bacteria. Likewise, combining nanoparticles with antimicrobial peptides and essential oils generates genuine synergy against bacterial resistance. In this article, we aim to summarize recent studies on interactions between nanoparticles and antibiotics, as well as other antibacterial agents to formulate new prospects for future studies. Based on the promising data that demonstrated the synergistic effects of antimicrobial agents with nanoparticles, we believe that this combination is a potential candidate for more research into treatments for antibiotic-resistant bacteria.

Gas gangrene and osteomyelitis of the foot in a diabetic patient treated with tea tree oil

Diabetic foot wounds represent a class of chronic non-healing wounds that can lead to the development of soft tissue infections and osteomyelitis. We reviewed the case of a 44-year-old female with a diabetic foot wound who developed gas gangrene while treating her wound with tea tree oil, a naturally derived antibiotic agent. This case report includes images that represent clinical examination and x-ray findings of a patient who required broad-spectrum antibiotics and emergent surgical consultation. Emergency Department (ED) detection of these complications may prevent loss of life or limb in these patients.

Physical properties of gum karaya-starch-essential oil patches

Essential oils are used in foods, cosmetics, and pharmaceuticals. Despite the recent marketing of novel essential-oil-containing patches, there is no information on their production, constituents, or physical properties. The objectives of this study were to produce essential-oil patches and characterize their physical properties. The essential oil of Lavandula angustifolia (lavender) was included at concentrations of 2.5% to 10% in patches manufactured from the exudate gum karaya, propylene glycol, glycerol, emulsifier, and optionally, potato starch as filler. Inclusion of essential oil reduced patch strength, stiffness, and elasticity relative to patches without essential oil. Inclusion of starch in the essential-oil patches strengthened them, but reduced their elasticity. Patches' adhesion to substrate was examined by both peeling and probe-tack tests: the higher the inclusion of essential oils within the patch, the larger the decrease in its adhesion to substrate. Addition of starch to essential-oil-containing patches increased their adhesion relative to their essential-oil-only counterparts. Scanning electron micrographs of the patches provided evidence of entrapped starch granules. Although inclusion of essential oil reduced both the mechanical properties and adhesion of the patches, a high proportion of essential oil can still be included without losing patch integrity or eliminating its adhesiveness to the skin.

Phytochemical Investigation of Verbesina Turbacensis Kunth: Trypanosome Cysteine Protease Inhibition by (–)-Bornyl Esters

The bark and leaf essential oils of Verbesina turbacensis were obtained by hydrodistillation and analyzed by GC-MS. The bark oil of the plant was composed mainly of monoterpene hydrocarbons (83.5-90.4%), predominately α-pinene, while the leaf oil was composed mainly of sesquiterpene hydrocarbons, dominated by germacrene-D (29.1-36.9%), and δ-elemene (21.7-22.1%). Three bornyl hydroxycinnamic esters isolated from the acetone bark extract were found to inhibit the cysteine protease, rhodesain. Molecular docking analysis to probe the inhibitory interactions of the esters was also carried out.