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Tea tree oil reduces histamine-induced skin inflammation
Abstract
Tea tree oil is the essential oil steam-distilled from Melaleuca alternifolia, an Australian native plant. In recent years it has become increasingly popular as an antimicrobial for the treatment of conditions such as tinea pedis and acne.
To investigate the anti-inflammatory properties of tea tree oil on histamine-induced weal and flare.
Twenty-seven volunteers were injected intradermally in each forearm (study and control assigned on an alternating basis) with histamine diphosphate (5 microg in 50 microL). Flare and weal diameters and double skin thickness were measured every 10 min for 1 h to calculate flare area and weal volume. At 20 min, 25 microL of 100% tea tree oil was applied topically to the study forearm of 21 volunteers. For six volunteers, 25 microL paraffin oil was applied instead of tea tree oil.
Application of liquid paraffin had no significant effect on histamine-induced weal and flare. There was also no difference in mean flare area between control arms and those on which tea tree oil was applied. However, mean weal volume significantly decreased after tea tree oil application (10 min after tea tree oil application, P = 0.0004, Mann-Whitney U-test).
This is the first study to show experimentally that tea tree oil can reduce histamine-induced skin inflammation.
... The results are somewhat similar to that of Koh et al. (2002), wherein they investigated the effect of tea tree essential oil on 21 human volunteers who developed weal and flares after being injected with histamine. It was revealed in their study that the diameter of the induced weal has been significantly reduced after applying tea tree oil on it. ...
... It was revealed in their study that the diameter of the induced weal has been significantly reduced after applying tea tree oil on it. This significant result can be attributed to its component, known as Terpinen-4-ol that can quell inflammation by limiting the secretion of monocytes responsible for this allergic symptom (Koh et al., 2002). Another in vitro study by Caldefie-Chézet et al. (2006), says that diluted tea tree essential oil has anti-inflammatory property on human leukocytes. ...
Background: Allergies are one of the most common chronic conditions worldwide. Due to the cost and possible side effects of pharmacologic treatments, aromatherapy, an alternative method in relieving allergies was studied. Objective: This study aimed to determine the effectiveness of Jojoba Oil and 100% Tea Tree Essential Oil combination through topical application as an alternative method for relieving severity and frequency of allergic symptoms triggered by aeroallergens. Methods: A pre-experimental one-group pre-test and post-test research design was used to determine whether the combination of Tea Tree and Jojoba Oil produced an effect to the respondents’ allergic signs and symptoms. A modified 3-part questionnaire was used to gather data from thirty (30) purposively selected college students. Results: It appeared that the combination oil when applied topically resulted to a reduction in the severity and frequency of the allergic symptoms; specifically watery eyes, nasal congestion, runny nose, nasal itching, sneezing, coughing, chest tightness, wheezing, shortness of breath and phlegm production. The observed alleviation of symptoms is deemed significant with P-values less than 0.05, except for the reduction in the frequency of wheezing (P-value=.101>0.05) and shortness of breath (P-value=.053>0.05) nonetheless. Conclusion: Hence, the combination oil composed of Tea Tree essential oil with 2% dilution and Jojoba carrier oil when applied topically to the hot spots of the body reduces allergic symptoms. Nurses and other public healthcare providers can consider aromatherapy in the treatment regimen of individuals who have allergies but prefers to manage it non-pharmacologically or does not have access to anti-allergy medications.
... The results showed that the formulated drug preserved the antimicrobial capacity of pure TTO, which can be attributed to the presence of terpinel-4-ol (Brand et al. 2002;Koh et al. 2002;Hammer 2015), the main component that provides antibacterial (Buldain et al. 2018;Venkitanarayanan et al. 2013;Kamath et al. 2019) and anti-inflammatory (Brand et al. 2002;Koh et al. 2002;Hammer 2015) actions to TTO. However, antifungal (Weseler et al. 2002;Kawakami et al. 2006), repellent (Thomas et al. 2018), and antiparasitic (Grando et al. 2016a(Grando et al. , 2016b actions were also described. ...
... The results showed that the formulated drug preserved the antimicrobial capacity of pure TTO, which can be attributed to the presence of terpinel-4-ol (Brand et al. 2002;Koh et al. 2002;Hammer 2015), the main component that provides antibacterial (Buldain et al. 2018;Venkitanarayanan et al. 2013;Kamath et al. 2019) and anti-inflammatory (Brand et al. 2002;Koh et al. 2002;Hammer 2015) actions to TTO. However, antifungal (Weseler et al. 2002;Kawakami et al. 2006), repellent (Thomas et al. 2018), and antiparasitic (Grando et al. 2016a(Grando et al. , 2016b actions were also described. ...
The effects of intramammary dry cow therapy based on the administration of 5% Melaleuca alternifolia tea tree essential oil (TTO) as an internal teat sealant to Murrah cows were evaluated. A longitudinal prospective and retrospective negative control study was performed using 12 buffaloes from a total of 20 Murrah buffaloes on an organic farm, with the cow used as a control for herself. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) for treatments with pure oil (TTO) and medication containing 5% TTO (O5) were determined. The buffaloes were clinically examined, and the teats were evaluated using thermography and ultrasound. Udder health was monitored during the first 100 days in milk (DIM) using milk somatic cell count (SCC) and California mastitis test (CMT). Laboratory tests against standard strains Staphylococcus aureus ATCC®25,923™, Escherichia coli ATCC®25,922™, and wild bacterial strains showed maximum MIC values of 50 µL/mL for the TTO and O5 treatments. One wild-type S. aureus strain showed no MBC. No adverse effects were observed after the intramammary application of TTO. The CMT and SCC values were similar (P > 0.05) for all observations. The medication containing 5% TTO was effective in vitro and compatible with the intramammary tissue in vivo of Murrah buffaloes. TTO was safe, not inducing inflammatory processes or other modifications of the teat detectable by thermography or ultrasound. It was able to protect buffaloes during the dry period under field conditions, demonstrating potential use as a teat sealant for organic farms.
... It was found to significantly decrease the flare after ten minutes of the administration of the doses. The study concluded that TTO could reduce histamine-induced inflammation (Koh et al., 2002). In another study, TTO at the dose of 0.125% was evaluated in vitro for the examination of human peripheral blood monocytes through the LPS-induced production of TNF-α, IL-1β, IL-8, IL-10, and PGE2 . ...
... Thus, it can be considered as a potential alternative to conventional acne treatment due to its weaker adverse effect (Bassett et al., 1990). The histamine-induced skin inflammation was diminished after using TTO, which could help in treating inflammation arising from acne (Koh et al., 2002) and the antimicrobial action could kill acne causing bacteria (Nenoff et al., 1996). Tinea pedis caused by T. rubrum, T. mentagrophytes, and Epidermophyton floccosum in sweaty toes was reported to be healed by TTO alone and its combination with 1% tolnaftate (10% (mass fraction) TTO cream) . ...
Over the past few decades, complementary and alternative treatments have become increasingly popular worldwide. The purported therapeutic characteristics of natural products have come under increased scrutiny both in vitro and in vivo as part of efforts to legitimize their usage. One such product is tea tree oil (TTO), a volatile essential oil primarily obtained from the native Australian plant, Melaleuca alternifolia, which has diverse traditional and industrial applications such as topical preparations for the treatment of skin infections. Its anti-inflammatory-linked immunomodulatory actions have also been reported. This systematic review focuses on the anti-inflammatory effects of TTO and its main components that have shown strong immunomodulatory potential. An extensive literature search was performed electronically for data curation on worldwide accepted scientific databases, such as Web of Science, Google Scholar, PubMed, ScienceDirect, Scopus, and esteemed publishers such as Elsevier, Springer, Frontiers, and Taylor & Francis. Considering that the majority of pharmacological studies were conducted on crude oils only, the extracted data were critically analyzed to gain further insight into the prospects of TTO being used as a neuroprotective agent by drug formulation or dietary supplement. In addition, the active constituents contributing to the activity of TTO have not been well justified, and the core mechanisms need to be unveiled especially for anti-inflammatory and immunomodulatory effects leading to neuroprotection. Therefore, this review attempts to correlate the anti-inflammatory and immunomodulatory activity of TTO with its neuroprotective mechanisms.
... Cufod. (Acanthaceae) (Fig. 1) is widely distributed in the tropics of Africa [8]. It is a robust, polymorphous shrub that grows up to 2 m long and has a characteristic quadrangular stem and violets on the underside of leaves. ...
... It is a robust, polymorphous shrub that grows up to 2 m long and has a characteristic quadrangular stem and violets on the underside of leaves. It is known in Cameroon as pang nyemshe (red on one side) and in southern Nigeria (Ibibio) as Edem ididot ("golden seal" or "African blood tonic") [8]. In addition Page 3 of 10 Ibok et al. ...
Background
Eremomastax speciosa (Hochst.) Cufod. ( Acanthaceae ) is a renowned medicinal plant used to ease menstrual cramps and treat female infertility, anaemia, dysentery, urinary tract infection and haemorrhoids. Essential oils and their constituents from herbs have also been utilised in the management of a good number of ailments in ethno-medicine. The chemical composition, antioxidant and antimicrobial activities of the stem essential oil are investigated in this study. The essential oil was obtained by hydro-distillation using an all-glass Clevenger apparatus. Identification and characterisation were done using Gas Chromatography–Mass Spectrometry, while antioxidant activity was evaluated with 2, 2-diphenyl-1 picrylhydrazyl radical (DPPH*) method. The antimicrobial property was assessed by the broth dilution method.
Results
The essential oil contained forty-three compounds constituting 62.87% of the total oil composition. It was dominated by non-terpene derivatives, of which (14β)-Pregnane (17.58%) is the most abundant compound. Other significant compounds identified in the essential oil include n -decane (2.3%), norbornane (2.2%), (−)-α-Copaene (1.5%), 10-epizonarene (1.5%), thymol (1.25) and (−)-α-phellandrene (1.12%). The essential oil exhibited significant antioxidant activity (IC 50 0.7296 μg/mL), which is more active than the standards; vitamin C (IC 50 0.8728 μg/mL) and butylated hydroxy anisole (IC 50 0.8729 μg/mL) used for the assay. Also, the oil inhibited significant bacterial and fungal strains at concentrations ranging from 100 to 3.125 μg/mL with a minimum inhibitory concentration between 3.5 and 6.5 μg/mL.
Conclusion
The chemical composition of the stem essential oil of E. speciosa could be responsible for the pharmacological applications of the plant in ethno-medicine and the chemical constituent of the stem essential oil of E. speciosa is reported for the first time.
Graphical Abstract
... It was discovered that TTO has antibacterial, antifungal, antiviral, and antiprotozoal activity [22][23][24][25][26][27]. Numerous studies have shown anti-inflammatory activity of TTO in vitro and in vivo [19,[28][29][30] that can help reduce inflammation of the scalp in the case of SD. Eucalyptol-1,8-cineole (1,3,3-trimethyl-2-oxabicyclo [2.2.2]acetate) is a main monoterpenoid of essential oils obtained from various Eucalyptus species [31] and has a mint-like smell. ...
... Based on the results, the composition was rich in monoterpenes and sesquiterpenes. These biologically active phytoconstituents have a range of activities such as antimicrobial [65], anti-inflammatory [19,[28][29][30][31][32][33], and antibiofilm [34,35,50] properties, skin southing [36], and membrane permeability enhancement [22,66,67]. The relative richness of the composition of the plant-based substance demonstrated complex antibacterial and antifungal activity against ATCC strains chosen in accordance with their involvement in the pathogenesis of SD. ...
Seborrheic dermatitis (SD) is the most prevalent dermatological disease, occurring in up to 50% of newborns, children, and adults around the world. The antibacterial and antifungal resistance contributed to the search for new natural substances and the development of a novel substance based on Melaleuca alternifolia (M. alternifolia) leaf oil (TTO), 1,8-cineole (eucalyptol), and α-(-)-bisabolol. Thus, this work aimed to determine the chemical composition of the novel plant-based substance and to evaluate its antimicrobial activity against standard microorganisms involved in the pathogenesis of SD. Moreover, the chemical composition of the substance was analyzed by gas chromatography coupled with mass spectrometry (GC/MS). Staphylococcus epidermidis (S. epidermidis), Staphylococcus aureus (S. aureus), Micrococcus luteus (M. luteus), and Candida albicans (C. albicans) were used for antimicrobial and antifungal assays by means of the broth microdilution method to determine the minimal inhibitory concentration (MIC). Finally, the substance’s ability to inhibit Malassezia furfur (M. furfur) was evaluated. Eighteen compounds from different chemical groups were identified by GC/MS. The major biologically active compounds of the substance were terpinen-4-ol (20.88%), 1,8-cineole (22.28%), (-)-α-bisabolol (25.73%), and o-cymene (8.16%). The results showed that the substance has a synergistic antimicrobial and antifungal activity, while S. epidermidis and C. albicans strains were the most susceptible. Furthermore, the substance inhibited M. furfur, which is a main pathogen involved in the pathogenesis of SD and clinical manifestations. It can be concluded that the novel plant-based substance has a promising potential against M. furfur and scalp commensal bacteria and may be helpful for the development of new drugs for treatment of dandruff and SD.
... Research has shown that essential oils are capable of acting as antioxidants. Depending on their chemical composition, secondary metabolites with conjugated double bonds and phenolic can be particularly effective antioxidants [6]. Because a lot of products on the market today are detrimental to people's wellbeing. ...
Medicinal plants have been utilised to treat illnesses and maintain good health. Traditionally, Allophylus spicatus Radlk (Sapindaceae) has been used to treat wounds, diarrhoea, cough, colds, dysentery, and various heart conditions. It has strong ethnopharmacological applications. Gas Chromatography-Mass Spectrometry (GC–MS) was used to analyse the essential oils (EOs), which were isolated via hydro-distillation. The 2, 2-diphenyl-1-picrylhydrazyl (DPPH) method was used to assess the antioxidant activities. The essential oils isolated from the leaves, twigs, and roots contained 30, 32, and 21 compounds overall, accounting for 89.5%, 95.8%, and 82.5% of the total compositions, respectively. β-elemene was the major constituent of volatile phytochemicals found in leaves, twigs, and roots, with percentage compositions of 15.2%, 20.5%, and 14.8%, respectively. Compared to α-tocopherol (0.546 mg/mL), a well-known antioxidant utilised as one of the standards at concentrations between 1.0 and 0.0625 mg/mL, the EOs demonstrated greater free radical scavenging activities (IC50 = 0.4746 mg/mL, 0.4172 mg/mL, and 0.4156 mg/mL). EOs from leaves, twigs and roots of A. spicatus and antioxidant activities is studied for the first time.
... Koh et al. performed intradermal injections of HIS diphosphate and topical applications of tea tree oil on the forearms of 27 volunteers. By measuring flare and weal diameters and double skin thickness, they found that tea tree oil significantly inhibits HIS-induced flare and weal, indicating an effective reduction in HIS-induced skin inflammation [78]. Formononetin inhibits HIS release and the secretions of TNF-α, IL-1β, and IL-6 and ameliorates allergic inflammation caused by the release of histamines by mast cells. ...
The incidence of skin sensitivity issues in human populations has increased steadily because of external factors, such as environmental changes and emotional stress. Skin sensitivity refers to a state of skin hyperreactivity that occurs under certain physiological or pathological conditions. Sensitive skin may manifest as redness, itching, and pain and even trigger skin diseases, such as eczema or dermatitis, in severe cases. This review discusses the sensitization mechanisms and characteristics of sensitive skin, with a focus on symptom alleviation through three key strategies: skin-barrier repair, reduction in TRPV1 receptor activity, and anti-inflammatory interventions utilizing active substances. The findings will enhance public knowledge regarding sensitive skin, promote further research and practical prevention and treatment methods, and provide theoretical support for developing soothing cosmetic products for sensitive skin.
... Tea tree oil was the oil of choice and was selected as the oil phase in order to develop synergetic anti-inflammatory and analgesic effects. Tea tree oil has the ability to modulate inflammatory pathways and penetrate the skin effectively [25,26], making it an ideal candidate for targeted drug delivery to inflamed joints, thereby augmenting the bioavailability and therapeutic effects of diclofenac and curcumin in the treatment of RA [27,28]. The oil of choice should possess the capacity to dissolve the requisite dosage of the drug effortlessly. ...
Rheumatoid arthritis, a chronic autoimmune disorder affecting millions worldwide each year, poses a significant threat due to its potential for progressive joint damage and debilitating pain if left untreated. Topical anti-inflammatory and analgesic treatments offer localized relief with reduced systemic side effects compared to conventional oral therapies, making them a promising option for managing rheumatoid arthritis. Therefore, the current study endeavored to formulate a microemulsion gel formulation loaded with diclofenac and curcumin for topical administration in the management of rheumatoid arthritis, utilizing Tea tree oil. The ratio of surfactant and cosurfactant was 4:1, assessed by pseudoternary phase diagram on the basis of the maximum emulsification region. The microemulsion underwent optimization using a Central Composite Rotatable Design (CCRD) with constraints of minimum particle size, polydispersity index, and maximum transmittance. The Curcufenac-T microemulsion had a particle size, polydispersity index (PDI), and transmittance of 151.82 ± 15.9 nm, 0.287 ± 0.021, and −5.78 ± 0.26 mV, respectively. DSC analyses confirmed the stability and compatibility of diclofenac and curcumin within the formulation. The microemulsion was changed into gel form by incorporating 1% carbopol-934. Skin permeation analysis revealed that the percentage of diclofenac permeated at 0.5 h from Curcufenac-T microemugel and the conventional gel was 12.1% and 3.9%, respectively, while at 12 h, the rates were 82.6% and 34.2%, respectively. In vitro permeability demonstrated significant potential for the effective delivery of diclofenac and curcumin to targeted sites, compared to conventional gel. Therefore, it was deduced that the Tea tree oil integrated diclofenac and curcumin microemulsion gel could enhance the effectiveness of diclofenac and serve as a promising vehicle for rheumatoid arthritis treatment.
... In the study by Koh et al. 16 titled "Tea tree oil reduces histamine-induced skin inflammation," the authors investigated the anti-inflammatory properties of tea tree oil on histamine-induced skin inflammation. The study utilized a rat model to evaluate the effects of tea tree oil on inflammatory markers such as edema and myeloperoxidase activity. ...
Background
Photoaging is a process of the architecture of normal skin damaged by ultraviolet radiation. Topical cosmeceuticals have been used to treat this condition. The authors aimed to understand the mechanism and level of evidence of different commonly used cosmeceuticals used to treat photodamaged skin.
Objective
A range of commonly used topical cosmeceuticals (botanicals, peptides, and hydroquinone) has been used in cosmetic medicine for many years to treat photodamaged skin. This review article compares their efficacy and level of evidence.
Material and methods
This study was a systematic review to evaluate the efficacy of different topical cosmeceuticals. Keywords including “Photoaging,” “Azelaic acid,” “Soy,” “Green Tea,” “Chamomile,” “Ginkgo,” “Tea Tree Oil,” “Resveratrol,” “Cucumber,” “Ginseng,” “Centella asiatica,” “Licorice Root,” “Aloe Vera,” “Peptides,” “Argireline,” “Hydroquinone,” were typed on OVID, PUBMED, MEDLINE for relevant studies published on photoaging treatment.
Results
Most of the evidence behind cosmeceuticals is of high‐quality ranging from Level I to Level II. In particular, the evidence base behind peptides is the strongest with most studies achieving Level Ib status in the evidence hierarchy.
Conclusion
Topical cosmeceuticals like botanicals, peptides and hydroquinone can effectively treat photodamaged skin
... Tea tree oil decreased the histamine reactivity of weal and flare in humans. After 10 minutes, topical applications of 100 percent tea tree oil can decrease the irritation caused by histamine diphosphate (Koh et al., 2002). Non cytotoxic doses of essential oils have been shown to have an antiinflammatory effect via boosting interleukin-10 production, according to existing evidence on different essential oils (Murbach et al., 2014). ...
Aromatherapy, a form of alternative medicine that uses essential oils and aromatic compounds for the purpose of altering a person's mind, mood and to get relief from numerous ailments like depression, indigestion, headache, insomnia, muscular pain, respiratory problems etc. The main motto of aromatherapy is the absorption and penetration of the essential oils to the human skin surface through inhalation and local application as the name signifies essential oils are much essential on one hand and friendlier on the other hand. The phytochemicals gets absorbed through skin or nose and lungs, ultimately reaches the limbic system-the nerve network in brain that controls emotion and instinct. It is medically proven that aromatherapy can lower cortisol level, heart rate, inflammation, depression or anxiety and alleviation from different problems like cerebral pain, stomach ache, conjunctivitis, mononucleosis, indigestion, arthritis, skin allergies, respiratory problems, cardiovascular disorders and urine associated diseases. This review probes the particulars present in the literature regarding the functioning of aromatherapy, its classification, different medicinal plants used, pharmacological actions and safety issues.
... Essential oils are essentially produced by plants to protect them from predators, attract pollinating agents, prevent seed germination, and communicate between different plants (1). The oils also possess a wide range of biological activities viz antipyretic, antibacterial, antifungal, anti-inflammatory, antispasmodic, antiseptic, anticholesterolemic, anthelmintic, cancer chemoprotective, antioxidant, carminative, sedative, expectorant, disinfectant, insecticidal (1,(3)(4)(5)(6)(7). Therefore, researchers across the globe are looking for useful plants which yield essential oils as they are the feedstock for many industrial applications. ...
... Tea tree oil reduced the histamine reactivity of flare and weal in people. 100% tea tree oil applied topically after 10 minutes can decrease the irritation caused by histamine diphosphate [28]. ...
This book series invites all the Specialists, Professors, Doctors, Scientists, Academicians, Healthcare professionals, Nurses, Students, Researchers, Business Delegates, and Industrialists across the globe to publish their insights and convey recent developments in the field of Nursing, Pharmaceutical Research and Innovations in Pharma Industry. Book series on Pharmacy and Nursing covers research work in a set of clinical sciences and medicine.
... The active ingredients of TTO are 1,8-cineole and terinen-4-ol, which exhibit antibacterial, antioxidant and anti-inflammatory activity. 5,26,27 Groppo et al 14 reported that TTO showed antimicrobial activity against mutans streptococci and other oral microorganisms. Mohammed et al 31 indicated that Melaleuca alternifolia extract may be useful for preventing P. gingivalis infection. ...
Purpose:
To evaluate the efficacy of the adjunctive use of tea tree oil (TTO) for dental plaque control and nonsurgical periodontal treatment (NSPT).
Materials and methods:
Three electronic databases were searched from 2003. The reference lists of the included articles and relevant reviews were also manually searched. Randomised controlled trials reporting the clinical outcomes of the topical use of TTO as an adjunct to daily oral hygiene or scaling and root planing (SRP) were included. Regarding the use of TTO as an adjunctive to daily oral hygiene, the primary outcome was plaque index (PI) reduction. Regarding the use of TTO as an adjunctive to SRP, probing pocket depth (PPD) reduction and clinical attachment level (CAL) gain were the primary outcomes. The secondary outcomes were adverse events.
Results:
Eleven studies were included for qualitative analysis, 9 studies were included for quantitative analysis, and 6 studies were included to examine the application of TTO mouthwash as an adjunctive to daily oral hygiene. In addition, three studies were included to analyse the subgingival use of TTO adjunctive to SRP at selected sites. The results indicated a nonsignificant improvement in PI reduction in the TTO mouthwash group compared with placebo. The incidence of adverse events was statistically significantly greater in the CHX group than in the TTO group. For subgingival use of TTO adjunctive to SRP, beneficial effects were observed in the TTO group compared with SRP alone in terms of PPD and CAL at both three and six months post-treatment. However, an unpleasant taste was reported in three out of four studies.
Conclusion:
There is a lack of strong evidence to support the beneficial effects of TTO. Studies with larger sample sizes and standardised evaluation criteria are needed to further demonstrate the clinical relevance of TTO.
... To our knowledge, this is the first report of a relationship between this bacterium and acne, which utilizes histidine decarboxylation as its sole source of energy, and is a histamine-producing bacterium (Garner et al., 2002). Histamine can cause vasodilation and increase vascular permeability, as well as modulate immune cell activity and inflammatory factor release (Koh et al., 2002). We hypothesized that the bacterium may play a proinflammatory role in the development of acne-associated inflammation by releasing histamine, but this hypothesis needs to be confirmed by further studies. ...
Background
Gut microbiota has been associated with dermatological problems in earlier observational studies. However, it is unclear whether gut microbiota has a causal function in dermatological diseases.
Methods
Thirteen dermatological diseases were the subject of bidirectional Mendelian randomization (MR) research aimed at identifying potential causal links between gut microbiota and these diseases. Summary statistics for the Genome-Wide Association Study (GWAS) of gut microbiota and dermatological diseases were obtained from public datasets. With the goal of evaluating the causal estimates, five acknowledged MR approaches were utilized along with multiple testing corrections, with inverse variance weighted (IVW) regression serving as the main methodology. Regarding the taxa that were causally linked with dermatological diseases in the forward MR analysis, reverse MR was performed. A series of sensitivity analyses were conducted to test the robustness of the causal estimates.
Results
The combined results of the five MR methods and sensitivity analysis showed 94 suggestive and five significant causal relationships. In particular, the genus Eubacterium_fissicatena_group increased the risk of developing psoriasis vulgaris (odds ratio [OR] = 1.32, pFDR = 4.36 × 10⁻³), family Bacteroidaceae (OR = 2.25, pFDR = 4.39 × 10⁻³), genus Allisonella (OR = 1.42, pFDR = 1.29 × 10⁻²), and genus Bacteroides (OR = 2.25, pFDR = 1.29 × 10⁻²) increased the risk of developing acne; and the genus Intestinibacter increased the risk of urticaria (OR = 1.30, pFDR = 9.13 × 10⁻³). A reverse MR study revealed insufficient evidence for a significant causal relationship. In addition, there was no discernible horizontal pleiotropy or heterogeneity.
Conclusion
This study provides novel insights into the causality of gut microbiota in dermatological diseases and therapeutic or preventive paradigms for cutaneous conditions.
... The antioxidant potential of organic substances mainly depends on their chemical composition. Phenolics and some other secondary metabolite compounds are linked by double bonds, which are responsible for the intrinsic antioxidant activity of EO [77]. Essential oils extracted from traditional plants are rich sources of oxygenated monoterpenes. ...
The production of safe food with high quality is one of the most important topics nowadays. The researchers have been looking for innovative approaches to the preparation of a new generation of emulsified products that can serve as a matrix carrier for the incorporation of valuable components with high functional potential. New products may have the capacity to prevent cardiovascular and central nervous system diseases, oncological diseases, and atherosclerosis. Finding and identifying new properties and applications of medicinal plants containing biologically active ingredients is of great importance in the future. Medicinal plants and their secondary metabolites are subject of interest in the pharmaceutical and food industries. In the article, the three valuable species of herbs: hawthorn fruit (Crataegus monogyna), thistle (Onopordum acanthium L.), thyme (Thymus callieri) and their potential for incorporation in food emulsions are reviewed. One hundred seventy-three literary sources were studied-studies of various scientific groups around the world. The research covers a significant range of results concerning plants as a source of biologically active substances, and the integration of plant extracts into food products. The antioxidant potential and chemical composition of plants as a bio-component for food matrices have been studied. A thorough characterization of the chemical composition, pharmacological activities, and biological potential of three plants distributed in the Republic of Bulgaria-hawthorn fruit (Crataegus monogyna), thistle (Onopordum acanthium L.), and thyme (Thymus callieri) was made. Their application in the food industry was studied. The potential possibilities for the preparation of food emulsion systems with the addition of plant sources have been examined. A broad overview of the innovative modern approaches for obtaining a new generation of emulsion products was made. The present review evaluates the possibilities of enhancing the biological potential and health effects of edible emulsion dispersion systems by incorporating plant extracts of medicinal plants into them.
... Its ability to mitigate inflammatory processes provides valuable insights into the design of more effective and targeted anti-inflammatory therapies. Koh et al. conducted the first experimental trials demonstrating TTOʹs ability to reduce histamine-induced skin inflammation [49]. Brand et al. postulated the ability of T-4-ol (0.013%) in mitigating inflammatory responses through suppression of superoxide radical production in human neutrophils and monocytes that were chemically (N-formyl-methionyl-leucyl-phenylalanine) and biologically (lipopolysaccharide) activated in vitro [50]. ...
Owing to their extensive biological potential, essential oils (EOs) and their bioactive phytochemicals have gained attention from the scientific community. Within this domain, Terpinen-4-ol (T-4-ol), a bioactive monoterpene alcohol and the major constituent of tea tree oil (TTO), has made its way into translational research. Recent literature on T-4-ol strongly indicates its diverse pharmacological properties, including but not limited to antimicrobial, antivirulent, antioxidant, anti-inflammatory, anti-hypertensive, and anti-cancer effects. Hence, this review provides a comprehensive overview of the multifaceted biological activities exhibited by T-4-ol, emphasizing its medicinal potential for widescale application. The antibacterial and antifungal effectiveness of T-4-ol has been discussed encompassing its role in combating a broad spectrum of bacterial and fungal pathogens, respectively. The review delves into the antivirulent prospects of T-4-ol, shedding light on its ability to attenuate virulence and mitigate bacterial pathogenesis. Scientific literature on the antioxidant and anti-inflammatory activity of T-4-ol highlighting its role in neutralizing reactive oxygen species and modulating inflammatory pathways has also been collated. Furthermore, the review elaborates on the cardioprotective and anti-hypertensive properties of T-4-ol and augments literature on its anti-cancer mechanism against various cancer cell lines. Overall, this review consolidates the existing knowledge on T-4-ol, providing a holistic understanding of its pharmacological abilities. The exploration of these diverse attributes positions T-4-ol as a promising candidate for further research and therapeutic repurposing in various biomedical applications.
... (2002) yaptıkları çalışmada, çay ağacı yağının deriye topikal uygulanmasının histamin kadar olmamakla birlikte ödemi azalttığını bildirmişlerdir. 26 Ayrıca farelerde ağızdan verilen çay ağacı yağının belirgin şekilde ödem ve damar geçirgenliğini azalttığı bulunmuştur. 27 Melaleuca alternifolia, mikrobiyal dental plak ve diş eti iltihabının kontrolünde ve periodontitiste lokal irrigasyona yardımcı bir ajan olarak da kullanılmaktadır. ...
... The chemical composition of medicinal and aromatic essential oils, in particular, affects their antioxidant capacity. Phenols and other secondary metabolites are linked by double bonds responsible for the massive antioxidant activity of the important oils (Koh, et al. 2002). ...
... There is also evidence that TTO can reduce histamine-induced skin inflammation through the intradermal injection of histamine diphosphate (5 µg in 50 µL), according to Kho et al. [122] who, for the first time, assayed the application of TTO (25 µL of pure oil) on injected histamine-induced weal and flare in the arms of more than twenty volunteers. The results showed that the mean weal volume significantly decreased 10 min after TTO application when compared to the control group in which liquid paraffin had been applied. ...
Acne vulgaris is an inflammatory dermatological pathology that affects mostly young people. However, it can also appear in adulthood, mainly in women. It has a high psychosocial impact, not only at the time of active lesions but also due to the consequences of lesions such as scarring and hyperpigmentation. Several factors are involved in the physiopathology of acne and the constant search for active ingredients is a reality, namely phytotherapeutic ingredients. Tea tree oil is an essential oil extracted from Melaleuca alternifolia (Maiden & Betch) Cheel with known antibacterial, anti-inflammatory, and antioxidant properties, making it a candidate for the treatment of acne. This review aims to describe the various properties of tea tree oil that make it a possible ingredient to use in the treatment of acne and to present several human studies that have evaluated the efficacy and safety of using tea tree oil in the treatment of acne. It can be concluded that tea tree oil has good antibacterial, anti-inflammatory, and antioxidant properties that result in a decrease in the number of inflammatory lesions, mainly papules, and pustules. However, given the diversity of study designs, it is not possible to draw concrete conclusions on the efficacy and safety of this oil in the treatment of acne.
... Terpinen-4-ol has been shown to reduce TNF-, IL-1, IL-8, and PGE2 production. It can also influence vasodilation and plasma extravasation (Koh et al. 2002). In a trial of 27 patients to assess the impact of tea oil on weeping or flare induced by histamine, the volume of mean weeping decreased significantly after 10 min of treatment (Khalil et al. 2004). ...
Psoriasis represents an immune-mediated disease with an unclear cause that’s marked by inflammation triggered by dysfunction in the immune system, which results in inflammation in various parts of the skin. There could be obvious symptoms, such as elevated plaques; these plaques may appear differently depending on the type of skin. This disease can cause inflammation in the elbows, lower back, scalp, knees, or other regions of the body. It can begin at any age, although it most commonly affects individuals between the ages of 50 and 60. Specific cells (such as T cells) have been observed to play an obvious role in the pathogenesis of psoriasis, in addition to specific immunological molecules such as TNF-, IL-12, IL-23, IL-17, and other molecules that can aid in the pathogenesis of psoriasis. So, during the past two decades, biologists have created chemical drugs that target these cells or molecules and therefore prevent the disease from occurring. Alefacept, efalizumab, Adalimumab, Ustekinumab, and Secukinumab are a few examples of chemical drugs. It was discovered that these chemical drugs have long-term side effects that can cause defects in the patient's body, such as the development of the rare but life-threatening disorder progressive multifocal leukoencephalopathy (PCL). Its rapidly progressive infection of the central nervous system caused by the JC virus and other drugs may cause increased production of neutralising anti-drug antibodies (ADA) and the risk of infusion reactions like pruritus, flushing, hypertension, headache, and rash. So, our context intends to talk in our review about natural products or plants that may have therapeutic characteristics for this disease and may have few or no side effects on the patient's body.
... Also, it is used to treat various female genital infections and as an immunity booster and as an antiseptic. It has recently found its various applications is cosmetic and medicinal aromatherapy and is widely utilized around the globe and studied by the researchers (Koh et al., 2002;Pazyar et al., 2013). ...
Essential oils (EOs) are the complex mixture of diverse array of volatile phytoconstituents. These EOs are isolated from every plant part (flowers, leaves, buds, bark, stem, rhizome, and roots) but mainly concentrated in leaves and flowers of the plants. They are primarily produced by specific secretory tissues known as glandular trichomes along with other secretory structures. Different extraction techniques are used for the isolation of EOs, but hydrodistillation and steam distillation are the most employed techniques all around the world. Terpenoids, mainly monoterpenes and sesquiterpenes, low-molecular-weight hydrocarbons, and their oxygenated derivatives, are the key phytoconstituents present in the EOs. Pertaining to the presence of diverse array of bioactive phytoconstituents, EOs are used from the primeval time in different traditional medicinal and healing systems for the cure of variety of ailments. Further, EOs are well known for their variety of biological potential such as antioxidant, cytotoxic, antimicrobial, anticancer, antifungal, antiparasitic, insecticidal, insect repellent, antiinflammatory, pain relievers, mode elevator, etc. Apart from these, now a days, EOs are widely used in various fields and industries like aromatherapy, cosmetics, perfume and fragrance, incense, food preservative, biopesticides, and insecticides industries. Owing to the widespread applications of EOs in day-to-day life, presently the EOs market is growing rapidly. Therefore, the present chapter aimed to discuss the importance of EOs in different fields and current trends in the utilization of EOs particularly in the field of aromatherapy, medicines, and food and nonfood industries.
... The included aroma oils are tea tree oil and lavender oil. Tea tree oil, which is generally known for an anti-infective effect, improves inflammatory skin diseases [42]. Lavender oil is mainly used for AD because it settles pruritus in AD by suppressing immunoglobulin E production [43]. ...
To overcome interruption of skin barrier in transdermal drug delivery, the microneedle (MN) patch penetrates the barrier by punching with its MNs. Setting a needleless patch (NL patch) as the control intervention, this study assessed the efficacy of a biodegradable hyaluronic acid MN patch (BHMN patch) for atopic dermatitis (AD) patients with dry skin. Similar two AD lesions were selected from the extremities of a participant. For one lesion, a BHMN patch was attached for 6–8 h on where an aroma cream was applied (BHMN patch group). Simultaneously, an NL patch was attached on the other lesion as in the BHMN patch group (NL patch group). For 2 weeks, the interventions were conducted 3 times a week. The local scoring AD (L-SCORAD) index, the visual analog scale for pruritus and skin dryness, skin hydration, the transepidermal water loss (TEWL), and safety were assessed. Fifteen participants finished this trial with no dropouts. Both groups improved the L-SCORAD index after 2 weeks (p < 0.05), but the score of the BHMN patch group decreased more than that of the NL patch group (p < 0.05). The other outcomes, except for the TEWL, also showed statistical significance in intragroup comparisons. Nevertheless, none of the other outcomes showed statistical significance in intergroup comparisons. The TEWL showed no statistical significance even in intragroup comparison. Recoverable minor adverse events were reported in three cases. Considering the result of L-SCORAD index, the BHMN patch may be effective for ameliorating AD. However, a large-scale confirmatory trial is necessary to reassess other outcomes.
Trial Registration: This study was registered with the Clinical Research Information Service, Republic of Korea (Submitted date: 04/01/2022, Registered date: 23/02/2022, The first participant enrollment: 01/12/2021, Registration No. KCT0007037).
... TTO has been reported to exhibit antibacterial, antifungal, antiviral, and antiprotozoal activity (Banes-Marshall et al., 2001;Carson et al., 2002;Carson and Riley, 1993;Hammer et al., 1996;Mikus et al., 2000;Nenoff et al., 1996). Numerous studies support the evidence attributing antiinflammatory activity to TTO in vitro and in vivo (Caldefie-Chezet et al., 2004;Hart et al., 2000;Koh et al., 2002;Pearce et al., 2005). ...
Context: Aging is closely related to reactive oxygen species (ROS). ROS increases the collagenase enzyme (MMP-1) levels and collagen degradation that causes skin wrinkling. Secang wood (Caesalpinia sappan L.) containing brazilin and brazilein has been shown to have photoprotective and antioxidant properties.
Aims: To evaluate the activity of C. sappan nanoemulgel as antiaging agent against the target protein, matrix metalloproteinases (MMPs), especially MMP-1, MMP-3, and MMP-9 by in silico assay and using in vivo assay through MMP-1 and collagen expression parameter.
Methods: C. sappan nanoemulgel was made by mixing the gel base with C. sappan nanoemulsion from heartwood extract. The C. sappan nanoemulsion was formulated using the Self Nanoemulsifying Drug Delivery System method. In vivo testing was conducted with a post-test-only control group design and used male Wistar rats. MMP-1 expression was examined using immunohistochemical techniques, and the amount of dermal collagen was observed with Picro Sirius Red staining. In silico assay using a computational method with Autodock 4.2 program.
Results: C. sappan nanoemulgel concentrations of 0.0625, 0.125, and 0.25% obstruct the expression of MMP-1 and collagen degradation. The bond energy value to MMP-1, MMP-3, and MMP-9 were -8.04, -10.40, and -8.70 kcal/mol (for brazilin); -8.82; -10.99, and -8.51 kcal/mol (for brazilein).
Conclusions: Nanoemulgel containing C. sappan nanoemulsion has a potential activity as an antiaging agent by repressing MMP-1 expression and dermal collagen degradation. C. sappan nanoemulgel 0.25% showed the best result as antiaging. Brazilin and brazilein from C. sappan inhibit the MMP-1, MMP-3, and MMP-9 by in silico assay.
... TTO has been reported to exhibit antibacterial, antifungal, antiviral, and antiprotozoal activity (Banes-Marshall et al., 2001;Carson et al., 2002;Carson and Riley, 1993;Hammer et al., 1996;Mikus et al., 2000;Nenoff et al., 1996). Numerous studies support the evidence attributing antiinflammatory activity to TTO in vitro and in vivo (Caldefie-Chezet et al., 2004;Hart et al., 2000;Koh et al., 2002;Pearce et al., 2005). ...
Context: The current epidemiological situation causes a new surge of interest to perspective antimicrobial formulations for proper skin hygiene.
Aims: To evaluate in vitro and in vivo the antimicrobial activity of a novel active quadrocomplex (QC) for skin hygiene based on Melaleuca alternifolia essential oil, eucalyptol, (-)-α-bisabolol and silver citrate. In addition, to analyze the phytochemical constituents by gas chromatography-mass spectrometry (GC-MS) and to assess the skin irritant potential after regular washing.
Methods: The phytochemical analysis was performed using GC-MS. The Minimum Inhibitory Concentrations (MICs) were assessed using a colony-counting method with resazurin. The type of pharmacological interaction was investigated using a modern checkerboard assay.
Results: The chemical composition exhibited 18 resolved phytochemicals with the highest concentrations for (-)-α-bisabolol (32.2%) and terpinen-4-ol (31.6%) through the GC-MS analysis. QC agents showed antimicrobial activity against Gram-positive and Gram-negative strains, with MIC values ranging from 1.25 to 40.00 mg/mL. The checkerboard assay demonstrated reduced MIC values for the combinations of QC agents against all reference strains. QC showed significant inhibition of Staphylococcus aureus growth with an average efficiency of 99.91% and Candida albicans 99.94 %. In vivo, the investigation of QC showed higher immediate and prolonged efficiency compared to base formulation (p
... Also, it is used to treat various female genital infections and as an immunity booster and as an antiseptic. It has recently found its various applications is cosmetic and medicinal aromatherapy and is widely utilized around the globe and studied by the researchers (Koh et al., 2002;Pazyar et al., 2013). ...
There are numerous foods and herbal plants that boost the immune system. They stimulate the activity of cells responsible for fighting infections. In fact, over centuries, people have relied on herbs and other plants for treating medical conditions and boosting immunity. Considering the worldwide coronavirus pandemic, natural immune boosters are being sought after in the current war against this viral infection. Most likely, immune-boosting plants help human health by tackling viruses, bacteria, and abnormal cells in the form of prevention, to support and strengthen the body’s natural immune system. In this chapter, we review several terrestrial species and plants from various sources including China, India, Europe, and Africa, which have long folklore use, and we provide information on the chemistry and biological activity where available.KeywordsFolklore medicines from Africa and ChinaImmune boost plantsElderberry (Sambucus nigra)Echinacea spp.
Astragalus
Ganoderma lucidum
India—Astavarga plants
... This is due to the oxidation process can be inhibited by different types of mechanisms and due to the possibility of antioxidant compounds acting in different ways, depending on the type of antioxidant (NAMIKI, 1990). Essential oil antioxidant activities ranging with the chemical compositions (Bhavaniramya et al. 2019;Koh et al. 2002). The antioxidant activity of essential oils possess many ways of acting such as free radical scavenger, initiation prevention and others ( Meat product manufacturers are among industries that suffer from the negative impacts of oxidation reactions . ...
Consumers' interest in food with less and/or free from synthetic additives has increased considerably in recent years. In this context, researchers and industries have concentrated efforts on developing alternatives to these compounds. Replacing synthetic additives in meat products is a challenge, given their importance for sensory characteristics and food safety. Complementary technologies combined with the replacement and/or reduction of synthetic additives (hurdle technologies) has been studied focusing on the protection and extension of the shelf life of meat products. This review reports alternatives for replacing and/or reducing the use of synthetic additives in meat derivatives, aiming at the development of more natural and simpler meat products, familiar to consumers and considered clean labels.
... Tea tree oil (TTO) is a herbal drug that has antimicrobial, anti-inflammatory, antifungal, antiviral, and antioxidant effects (12)(13)(14)(15). Studies showed useful effects of local delivery of this product in the management of periodontal diseases (11,16,17). ...
... show remarkable antioxidant activities due to their phenolic structure which neutralize free radicals and decompose peroxides [40]. Essential oils are also used as potential anti-inflammatory agents in the treatment of arthritis, allergies and rheumatism [41,42]. Moreover, other work studies reported that EO extracted from Melissa officinalis L. [43], Saussurea lappa L. [44], Artemisia herba-alba Asso. ...
Psoriasis is a noncontagious, autoimmune chronic inflammatory disease with an unknown root cause. It is classified as a multifactorial and chronic skin disorder that also affects the immune system and is genetic. Environmental factors such as stress, infections, and injuries all play an important role in the disease's development. Although there is no cure for this disease, topical, oral, and systemic whole‐body treatments are available to relieve symptoms. Several plants and phytochemicals which have been found effective in the management of the psoriasis experimentally (preclinical and clinical). These plants/phytochemicals have applications in topical, oral, and systemic treatments. Traditionally, some of the plants have been utilized as the primary treatment, including their extracts and/or phytochemicals, for individuals with moderate to severe psoriasis (due to fewer side effects), while phototherapy is generally reserved for more advanced cases. This report describes various plants and phytochemicals that have been found to be effective against psoriasis in in vitro, preclinical, and clinical studies. This review summarizes the key findings from experimental studies on various pathological aspects of psoriasis and may be useful, effective, and informative for future research.
Oxidative stress, characterized by an overproduction of reactive oxygen species that overwhelm the body’s physiological defense mechanisms, is a key factor in the progression of parasitic diseases in both humans and animals. Scabies, a highly contagious dermatological condition caused by the mite Sarcoptes scabiei var. hominis, affects millions globally, particularly in developing regions. The infestation leads to severe itching and skin rashes, triggered by allergic reactions to the mites, their eggs, and feces. Conventional scabies treatments typically involve the use of scabicidal agents, which, although effective, are often associated with adverse side effects and the increasing threat of resistance. In light of these limitations, there is growing interest in the use of medicinal plants as alternative therapeutic options. Medicinal plants, rich in bioactive compounds with antioxidant properties, offer a promising, safer, and potentially more effective approach to treatment. This review explores the role of oxidative stress in scabies pathogenesis and highlights how medicinal plants can mitigate this by reducing inflammation and oxidative damage, thereby alleviating symptoms and improving patient outcomes. Through their natural antioxidant potential, these plants may serve as viable alternatives or complementary therapies in the management of scabies, especially in cases where resistance to conventional treatments is emerging.
Psoriasis is a chronic inflammatory disease that affects around 2–3% of the world’s population. The treatment for this autoimmune disease still remains centered around conventional methods using synthetic substances, even though more recent advancements focus on biological therapies. Given the numerous side effects of such treatments, current research involves plant extracts and constituents that could prove useful in treating psoriasis. The aim of this narrative review is to highlight the most known representatives belonging to classes of natural compounds such as polyphenols (e.g., astilbin, curcumin, hesperidin, luteolin, proanthocyanidins, and resveratrol), alkaloids (e.g., berberine, capsaicin, and colchicine), coumarins (psoralen and 8-methoxypsoralen), and terpenoids (e.g., celastrol, centelloids, and ursolic acid), along with plants used in traditional medicine that could present therapeutic potential in psoriasis. The paper also provides an overview of these compounds’ mechanisms of action and current inclusion in clinical studies, as well as an investigation into their potential incorporation in various nanotechnological systems, such as lipid-based nanocarriers or polymeric nanomaterials, that may optimize their efficacy during treatment.
Atopic dermatitis is a widespread and chronic dermatological disorder that affects a significant portion of the global population. The intricate etiology and pathophysiology necessitate multifaceted therapeutic approaches. Although existing treatments provide relief, their high dosage requirements and elevated systemic titer contribute to alarming side effects, often leading to the discontinuation of conventional therapy. To mitigate these side effects, there is a shift of focus from systemic delivery to site-specific delivery, specifically topical delivery. Moreover, the multifaceted role of phytoconstituents proves beneficial in effectively targeting atopic dermatitis without inducing extensive side effects. However, the clinical exploration of phytoconstituents is hindered by their poor physicochemical properties. Therefore, it is intriguing to investigate how newer formulation technologies, such as nanotechnology, can contribute to the success of these phytoconstituents. This review highlights the emerging role of nanotechnology, particularly lipid-based nanotherapies, in optimizing drug delivery and potentially improving atopic dermatitis management. The integration of these lipid-based monotherapies with phytotherapeutics (lipidic phytonanotherapeutics) is explored as a promising avenue for enhanced therapeutic outcomes.
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.
Background
In the continuous endeavor to find safe and efficient treatments for Atopic Dermatitis (AD), there remains a considerable focus on dietary adjustments. Nevertheless, the limited availability of research and conflicting findings in the academic literature pose a hurdle in establishing conclusive recommendations.
Method
Mendelian randomization (MR) was applied to the most comprehensive genome‐wide association studies (GWAS) data on tea intake (447 485), green tea intake (n = 64 949), flavored milk intake (n = 64 941), never eat eggs, dairy, wheat, sugar: Wheat products(n = 461 046), never eat eggs, dairy, wheat, sugar: Sugar or foods/drinks containing sugar (n = 461 046), never eat eggs, dairy, wheat, sugar: I eat all of the above (n = 461 046) and atopic dermatitis (n = 218 467). We used the inverse‐variance weighted method (IVW) as the primary method.
Results
The IVW analyses have demonstrated an increased tea intake was genetically associated with a reduced risk of AD (odds ratio [OR]: 0.646, 95% confidence interval [CI]: 0.430–0.968, p = 0.034). Furthermore, green tea intake was significantly negatively associated with AD (IVW OR: 0.986, 95% CI: 0.975–0.998; p = 0.024) in the IVW model. AD risk could be reduced by never eating wheat products (IVW OR: 8.243E‐04, 95% CI: 7.223E‐06–9.408E‐02, p = 0.003). There was no association between never eating eggs, dairy, wheat, sugar: Sugar, or foods/drinks containing sugar, I eat all of the above and AD.
Conclusions
Our MR study suggests a causal relationship between tea intake, green tea intake, and the avoidance of eating wheat products with atopic dermatitis. Our findings recommend that preventing and managing atopic dermatitis may be achieved by never eating wheat products while increasing tea and green tea intake.
Aromatherapy is a medical practice that uses aromatic compounds or essential oils to influence mood and health. Essential oils used in aromatherapy are created from a wide variety of medicinal plants, flowers, herbs, roots, and trees that are found all over the world and have significant, well-documented benefits on enhancing physical, emotional, and spiritual wellbeing.
This book is a comprehensive reference on aromatic compounds present in essential oils and their therapeutic use. Starting from fundamentals of essential oil biosynthesis the book guides the reader through their basic biochemistry, toxicology, profiling, blending and clinical applications. The concluding chapters also present focused information about the therapeutic effects of essential oils on specific physiological systems, plant sources, skin treatment and cancer therapeutics.
The combination of basic and applied knowledge will provide readers with all the necessary information for understanding how to develop preclinical formulations and standard clinical therapies with essential oils. This is an essential reference for anyone interested in aromatherapy and the science of essential oils.
Skin microbiota is an integral part of the human immune system. Staphylococcus aureus is one of the essential components of the normal flora. Approximately 20-30% of healthy individuals are persistently colonized with S. aureus, whereas the remainders are considered low-level intermittent carriers. Despite these natural aspects of existence, S. aureus can be a major opportunistic human pathogen. This versatile microorganism can infect a variety of anatomical sites, causing a broad spectrum of pathologies ranging from superficial to invasive infections. It developed a variety of strategies to adopt to a changing microenvironment. This attributed to the emergence of resistance to antibiotics of different classes during the past six decades. Methicillin-resistant S. aureus (MRSA) was originally confined to health-care settings (health-care-associated MRSA). Later on, community-acquired MRSA was identified as another source of infections. Recent figures indicate that MRSA strains have been associated with approximately 75% of all S. aureus infections worldwide. Several guidelines have been published to establish an adequate treatment of skin and soft tissue infections (SSTIs) caused by MRSA strains. In the first part of this review, we focus on current treatment guidelines with a focus on medical drug therapy, but drug therapy has its own limitations. Recently, the interest in herbal remedies has greatly increased. There is growing evidence of antimicrobial activity of medicinal plants and their extracts. The second part of this review is dedicated to herbal compounds to circumvent antibiotic resistance. Herbal compounds may potentiate the action of antibiotics and restore the activities of antibacterial agents against which S. aureus has developed a drug resistance. Part 2 focuses on the role of S. aureus in pathology of the two major inflammatory skin diseases, i.e., atopic dermatitis (AD) and psoriasis. Finally, Part 3 provides an overview on natural compounds with antimicrobial activity against S. aureus and possible use in the treatment of SSTIs,
Background
Psoriasis is a chronic inflammatory and proliferative skin disorder characterized by redness and elevated patches covered in scaly, silvery-white skin. The National Psoriasis Foundation categorizes psoriasis into mild, moderate, and severe, impacting 2% to 5% of the global population. This article explores the types, development, and severity categories of psoriasis, delving into its pathophysiology. It also reviews both conventional and herbal topical therapies and their marketed formulations.
Aim
The study aimed to contribute to the development of personalized treatment approaches for individuals with psoriasis.
Objectives
This article explores the types, development, and severity categories of psoriasis, delving into its pathophysiology. It also reviews both conventional and herbal topical therapies and their marketed formulations.
Methods
The article relies on a comprehensive review of existing literature and research studies on psoriasis. Information on types, severity categories, pathophysiology, and available treatments, both conventional and herbal, is gathered and analyzed.
Results
The results highlight the potential advantages of incorporating herbal therapies into treatment plans for individuals with psoriasis, especially for those with severe cases.
Conclusion
In conclusion, the article emphasizes the importance of individualized treatment plans for managing psoriasis. Both conventional and herbal topical formulations can be viable options, particularly for severe cases. By considering the safety profiles, side effects, and biological activities associated with these treatments, healthcare experts can collaborate with patients to create personalized and effective strategies for addressing the complexities of psoriasis management.
Aromatherapy, a part of herbology, is one of today's rapid-developing treatments. Fundamental oils are best utilized asback rubs, shower oils, or inward breaths. It is often accounted for that fragrance-based treatment leaves one inclination elevated,animated, empowered, or restored, contingent upon the oil utilized. At the point when breathed in, the different smells infiltratethe circulatory system through the lungs, causing physiologic changes. Aromatherapy is a form of alternative medicine.Aromatherapy is becoming increasingly popular, and there are clear indications that it should be used. It is one of thecomplementary therapies for anxiety reduction. Derived aroma molecules from essential oils contain curative and preventive usesin the medicine department. Although the perception and reaction to essential oils appear to differ significantly between men andwomen, aromatherapy benefits people of all ages. This article mainly focuses on a narrative review of aromatherapy, Derivatives,and uses of essential oils with a widened horizon in Aromatology.
A BSTRACT
The most common sequela of wearing removable dentures is denture stomatitis. This review article uses a Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) format to collect data regarding articles that report on the treatment of denture stomatitis using tissue conditioners modified with antifungal drugs, inorganic compound, and phytomedicines. Their advantages, disadvantages, and mechanism of action are discussed.
The genus Euphorbia includes about 2,000 species commonly widespread in both temperate and tropical zones that contain poisonous milky juice fluid or latex. Many species have been used in traditional and complementary medicine for the treatment of various health issues such as dropsy, paralysis, deafness, wounds, warts on the skin, and amaurosis. The medicinal applications of these species have been attributed to the presence of various compounds, and most studies on Euphorbia species have focused on their latex. In this review, we summarize the current state of knowledge on chemical composition and biological activities of the latex from various species of the genus Euphorbia. Our aim was to explore the applications of latex extracts in the medical field and to evaluate their ethnopharmacological potential. The databases employed for data collection, are obtained through Web of Science, PubMed, Google Scholar, Science Direct and Scopus, from 1983 to 2022. The bibliographic data indicate that terpenoids are the most common secondary metabolites in the latex. Furthermore, the latex has interesting biological properties and pharmacological functions, including antibacterial, antioxidant, free radical scavenger, cytotoxic, tumor, anti-inflammatory, healing, hemostatic, anti-angiogenic, insecticidal, genotoxic, and mutagenic activities. However, the role of other components in the latex, such as phenolic compounds, alkaloids, saponins, and flavonoids, remains unknown, which limits the application of the latex. Future studies are required to optimize the therapeutic use of latex extracts.
The aim of the present study is to reveal the mechanism of quercetin compound from M. calabura fruit extract in anti-inflammatory reaction using in silico studies. In silico screening of quercetin against the crucial inflammatory molecular target COX-2 was done using DS 2.1 tool. Maximum binding affinity of −2.583 was exhibited against COX-2. In silico modeling confirms the anti-inflammatory efficacy of quercetin. From the in silico analysis, we infer that quercetin has great efficacy in anti-inflammatory activity which could be used to treat inflammatory diseases.Key words
Muntingia calabura
QuercetinAnti-inflammatoryIn vivoIn silico
Ficus talboti King (Moraceae) is broadly utilized for different diseases, for example, diabetes, diarrhea, leucorrhea, menorrhea, vaginal diseases, and hemostatic, laxative, and nervous disorder. This study aims to investigate the free radical scavenging, antinociceptive and anti-inflammatory capacities of methanol extract of F. talboti stem bark (MEFt). To assess the antinociceptive and anti-inflammatory capacities of the concentrates (petroleum ether, chloroform, acetone, methanol, and hot water), five in vitro test frameworks were utilized, i.e., ABTS, FRAP, phosphomolybdenum, metal chelating limit, and DPPH extremist searching examines. MEFt at doses of 100 and 200 mg/kg body weight, p.o. was to evaluate anti-inflammatory and antinociceptive activity by various models. The total phenolic (78.18 g GAE/100 g remove) content was quantified to be higher in MEFt. In addition, the free radical scavenging capacities of ABTS (6812.22 μM TE/g concentrate) and DPPH (IC50 1.32 μg/mL) models indicated MEFt with higher action. The antinociceptive uncovered that MEFt has higher action at a portion of 200 mg/kg in hot plate test (12.05%), acidic acid-induced writhing test (32.54%), and formalin-initiated paw licking test (75.69%). In addition, the mitigating movement of MEFt additionally appeared by the decrease of paw edema measurement in both carrageenan- and egg albumin-induced paw edema models. Explanatory impacts on cotton pellet-induced granuloma in rodents have demonstrated noteworthy decrease in the weight of granuloma (69.30%) by MEFt at 200 mg/kg. HPLC analysis revealed the presence of bioactive compound quercetin which may be liable for all pharmacological activities. This study shows that MEFt have critical antiradical, antinociceptive, and anti-inflammatory and mitigating action conceivably because of the presence of phenol constituents.Key words
Ficus talboti
AntioxidantAnti-inflammatoryCarrageenanHistamine
Artemisinin is the most potent antimalarial drug obtained from Artemisia annua. However, this metabolite found in low amounts in natural sources has led to its production that is insufficient. Because of the significance of this drug, experts from all over the globe have been researching for new ways to expand its production. The goal of this review is to highlight current advances in plant cell culture production. Selection of high-yielding cell lines, adjustment of culture conditions, plant growth regulators, and elicitation are all described as ways for boosting artemisinin levels in plant cells. Different researchers researching on this topic from across the world are also taken into account. The necessities for continuous and dependable manufacturing systems as well as future prospects are also incorporated to address market demand.Key words
Artemisia annua
ArtemisininCallus cultureSuspension culturePlant growth regulatorsSecondary metabolites
Piliostigma thonningii (Milne-Redhead, Fabaceae) is used for various medicinal purposes in African countries with some pharmacological activities established from the crude extracts including antibacterial, antihelminthic, anti-inflammatory, and antilipidemic activities. In the present study, crude methanolic extract of Piliostigma thonningii was examined for its antioxidant activity and phytochemical constituents. The antioxidant assay was determined by the free radicals scavenging activity measured in terms of hydrogen donation or radical scavenging ability using the stable radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) and determined by UV spectrophotometer at 517 nm. The concentration of the plant crude methanolic extract required for 50% inhibition of DPPH radical scavenging effect (IC50) was recorded as 0.02 mg/ml as against a value of 0.015 mg/ml recorded for vitamin C used as standard. The crude methanolic extract showed potent inhibition of DPPH radical scavenging activity which is quite comparable to that of the Vitamin C standard. Qualitative phytochemical screening of the crude extract showed that it tested positive for saponins, flavonoids, terpenoids, steroids, alkaloids, and phenols indicating the presence of these phytochemicals, while tannins, phlobatannins, glycosides, triterpenoids, carbohydrates, resins, and anthraquinones were absent. Quantitative phytochemical analysis revealed that the crude extract contained 3.2% saponins, 1.6% flavonoids, 1.8% alkaloids, and 0.7% phenols. Bioassay-guided fractionation of the extract yielded five flavonoids which were identified by spectral analysis as piliostigmin (1), myricetin (2), kaempferide-3-O-β-D-glucoside (3), quercetin-3-O-β-glucoside (4), and quercetin-3-O-β-rhamnoside (5). The results of this study shows that extracts of Piliostigma thonningii could be a potent therapeutic agent for various diseases.Key wordsAntioxidantFlavonoid
Piliostigma thonningii
Phytochemical
Objective and Design: To evaluate potential anti-inflammatory properties of tea tree oil, the essential oil steam distilled from the Australian native plant, Melaleuca alternifolia.¶Material and Methods: The ability of tea tree oil to reduce the production in vitro of tumour necrosis factor-α (TNFα), interleukin (IL)-1β, IL-8, IL-10 and prostaglandin E2 (PGE2) by lipopolysaccharide (LPS)-activated human peripheral blood monocytes was examined.¶Results: Tea tree oil emulsified by sonication in a glass tube into culture medium containing 10% fetal calf serum (FCS) was toxic for monocytes at a concentration of 0.016% v/v. However, the water soluble components of tea tree oil at concentrations equivalent to 0.125% significantly suppressed LPS-induced production of TNFα, IL-1β and IL-10 (by approximately 50%) and PGE2 (by approximately 30%) after 40 h. Gas chromatography/ mass spectrometry identified terpinen-4-ol (42%), α-terpineol (3%) and 1,8-cineole (2%, respectively, of tea tree oil) as the water soluble components of tea tree oil. When these components were examined individually, only terpinen-4-ol suppressed the production after 40 h of TNFα, IL-1β, IL-8, IL-10 and PGE2 by LPS-activated monocytes.
Conclusion: The water-soluble components of tea tree oil can suppress pro-inflammatory mediator production by activated human monocytes.
All 66 isolates of Staphylococcus aureus tested were susceptible to the essential oil of Melaleuca alternifolia, or tea tree oil, in disc diffusion and modified broth microdilution methods. Of the isolates tested, 64 were methicillin-resistant
S. aureus (MRSA) and 33 were mupirocin-resistant. The MIC and MBC for 60 Australian isolates were 0·25% and 0·50%, respectively. Comparable results were obtained by co-workers in Britain
using similar methods. These in-vitro results suggest tea tree oil may be useful in the treatment of MRSA carriage.
To evaluate the regulatory properties of the essential oil of Melaleuca alternifolia (tea tree oil) on the production of oxygen derived reactive species by human peripheral blood leukocytes activated in vitro.
The ability of tea tree oil to reduce superoxide production by neutrophils and monocytes stimulated with N-formyl-methionyl-leucyl-phenylalanine (fMLP), lipopolysaccharide (LPS) or phorbol 12-myristate 13-acetate (PMA) was examined.
The water-soluble fraction of tea tree oil had no significant effect on agonist-stimulated superoxide production by neutrophils, but significantly and dose-dependently suppressed agonist-stimulated superoxide production by monocytes. This suppression was not due to cell death. Chemical analysis identified the water-soluble components to be terpinen-4-ol, alpha-terpineol and 1,8-cineole. When examined individually, terpinen-4-ol significantly suppressed fMLP- and LPS- but not PMA-stimulated superoxide production; alpha-terpineol significantly suppressed fMLP-, LPS- and PMA-stimulated superoxide production; 1,8-cineole was without effect.
Tea tree oil components suppress the production of superoxide by monocytes, but not neutrophils, suggesting the potential for selective regulation of cell types by these components during inflammation.
Objective:
To evaluate the safety and efficacy of a chimeric monoclonal antibody to tumor necrosis factor alpha (TNF alpha) in the treatment of patients with rheumatoid arthritis (RA).
Methods:
Twenty patients with active RA were treated with 20 mg/kg of anti-TNF alpha in an open phase I/II trial lasting 8 weeks.
Results:
The treatment was well tolerated, with no serious adverse events. Significant improvements were seen in the Ritchie Articular Index, which fell from a median of 28 at study entry to a median of 6 by week 6 (P < 0.001), the swollen joint count, which fell from 18 to 5 (P < 0.001) over the same period, and in the other major clinical assessments. Serum C-reactive protein levels fell from a median of 39.5 mg/liter at study entry to 8 mg/liter at week 6 (P < 0.001), and significant decreases were also seen in serum amyloid A and interleukin-6 levels.
Conclusion:
Treatment with anti-TNF alpha was safe and well tolerated and resulted in significant clinical and laboratory improvements. These preliminary results support the hypothesis that TNF alpha is an important regulator in RA, and suggest that it may be a useful new therapeutic target in this disease.
S ummary
Tea tree oil (an essential oil derived primarily from the Australian native Melaleuca alternifolia) has been used as a topical antiseptic agent since the early part of this century for a wide variety of skin infections; however, to date, the evidence for its efficacy in fungal infections is still largely anecdotal. One hundred and four patients completed a randomized, double‐blind trial to evaluate the efficacy of 10% w/w tea tree oil cream compared with 1% tolnaftate and placebo creams in the treatment of tinea pedia. Significantly more tolnaftate‐treated patients (85%) than tea tree oil (30%) and placebo‐treated patients (21%) showed conversion to negative culture at the end of therapy (p◂0.001); there was no statistically significant difference between tea tree oil and placebo groups. All three groups demonstrated improvement in clinical condition based on the four clinical parameters of scaling, inflammation, itching and burning. The tea tree oil group (24/37) and the tolnaftate group (19/33) showed significant improvement in clinical condition when compared to the placebo group (14/34; p = 0.022 and p = 0.018 respectively). Tea tree oil cream (10% w/w) appears to reduce the symptomatology of tinea pedis as effectively as tolnaftate 1% but is no more effective than placebo in achieving a mycological cure. This may be the basis for the popular use of tea tree oil in the treatment of tinea pedis.
Tea-tree oil (an essential oil of the Australian native tree Melaleuca alternifolia) has long been regarded as a useful topical antiseptic agent in Australia and has been shown to have a variety of antimicrobial activities; however, only anecdotal evidence exists for its efficacy in the treatment of various skin conditions. We have performed a single-blind, randomised clinical trial on 124 patients to evaluate the efficacy and skin tolerance of 5% tea-tree oil gel in the treatment of mild to moderate acne when compared with 5% benzoyl peroxide lotion. The results of this study showed that both 5% tea-tree oil and 5% benzoyl peroxide had a significant effect in ameliorating the patients' acne by reducing the number of inflamed and non-inflamed lesions (open and closed comedones), although the onset of action in the case of tea-tree oil was slower. Encouragingly, fewer side effects were experienced by patients treated with tea-tree oil.
With the recent development of selective drugs acting on the kinin system and the identification of a kallikrein-like enzyme from psoriatic blister fluid, there is now much interest in the possible role of kinins in psoriasis. We have examined the time-course of the inflammatory (weal and flare) responses to intradermal kallidin (lysbradykinin) and hradykinin in normal volunteers, and have compared the dose–response effect of these agents in normal volunteers and patients with psoriasis.
Initially, normal subjects (n= 5) received coded intradermal injections of 50μl normal saline containing kallidin or bradykinin (0.1, 0.5, 1.0 and 5.0μg). Weal volume, weal area and flare area were calculated at 5, 15, 30 and 60min by measuring two perpendicular diameters and change in skinfold thickness. Weal and flare measurements were subsequently made at 15 and 5 min, respectively.
Patients with psoriasis (n= 9) and normal subjects (n= 10) were given intradermal injections of kallidin (0.1 and 1.0μg) and bradykinin (0.1, 0.5 and 1.0 μg) in clinically normal forearm skin, using histamine and normal saline as controls.
The dose–response effects of kallidin on weal and dare responses in human skin were established in the study and compared with those of bradykinin. There was wide inter-individual variability for both agents and, although mean responses to the highest doses of kallidin and bradykinin were decreased in psoriatic skin, no significant differences were found between the psoriatic and normal group for kallidin, bradykinin or histamine.
Hence, there do not appear to be any obvious altered vascular responses to kallidin or bradykinin in patients with psoriasis, despite the fact that kinins may be generated in psoriatic tissue.
The purpose of this study was to determine the susceptibility of a range of transient and commensal skin flora to the essential oil of Melaleuca alternifolia, or tea tree.
A modified broth microdilution method was used. Polyoxyethylene sorbitan mono-oleate detergent was added to the test medium to enhance solubility of the tea tree oil.
Serratia marcescens had the lowest minimum inhibitory concentration (MIC90) of 0.25%. The highest MIC90 was 3% for Pseudomonas aeruginosa. The lowest minimum bactericidal concentration (MBC90) was 0.25% for S. marcescens and Klebsiella pneumoniae, whereas the highest was 8% for Staphylococcus capitis.
S. aureus and most of the gram-negative bacteria tested were more susceptible to tea tree oil than the coagulase-negative staphylococci and micrococci. These results suggest that tea tree oil may be useful in removing transient skin flora while suppressing but maintaining resident flora.
The in vitro antifungal activity of tea oil, the essential oil of Melaleuca alternifolia, has been evaluated against 26 strains of various dermatophyte species, 54 yeasts, among them 32 strains of Candida albicans and other Candida sp. as well as 22 different Malassezia furfur strains. Minimum inhibitory concentrations (MIC) of tea tree oil were measured by agar dilution technique. Tea tree oil was found to be able to inhibit growth of all clinical fungal isolates. For the investigated dermatophytes MIC values from 1,112.5 to 4,450.0 micrograms/ml with a geometric mean of 1,431.5 micrograms/ml were demonstrated. Both C. albicans strains and the other strains belonging to the genus Candida and Trichosporon appeared to be slightly less susceptible to tea tree oil in vitro. However, their MIC values, which varied from 2,225.0 to 4,450.0 micrograms/ml (geometric mean 4,080 micrograms/ml), indicated moderate susceptibility to the essential oil of M. alternifolia. The lipophilic yeast M. furfur seemed to be most susceptible to tea tree oil. MIC values between 556.2 and 4,450.0 micrograms/ml (geometric mean 1,261.5 micrograms/ml) were found against the tested M. furfur strains. However, when calculated as percentage tea tree oil of the agar, the above-mentioned concentrations correspond to 0.5-0.44% tea tree oil content. These values are far below the usual relatively high therapeutic concentrations of the agent; approximately 5-10% solution or even the concentrated essential oil are used for external treatment. In comparison with tea tree oil, in vitro susceptibility against miconazole, an established topical antifungal, was tested. As expected, very low MIC values for miconazole were found for dermatophytes (geometric mean 0.2 microgram/ml), yeasts (geometric mean 1.0 microgram/ml), and M. furfur (geometric mean 2.34 micrograms/ml). It is suggested that the in vivo effect of tea tree oil ointment in the therapy of fungal infections of the skin and mucous membranes as well as in the treatment of dandruff, a mild form of seborrheic dermatitis, may be at least partly due to an antifungal activity of tea tree oil.
Using reverse transcriptase polymerase chain reaction we showed that freshly plucked human anagen hair expressed both type 1 (80 kD) and type 2 (60 kD) interleukin (IL)-1 receptor mRNAs. The IL-1 receptor type 1 was functional since after in vitro stimulation of plucked hair with IL-1 alpha, we observed the induction of mRNA(s) for the inflammatory cytokines IL-1 beta, tumour necrosis factor alpha and IL-6 as well as for the chemokines monocyte chemotactic and activating factor and IL-8. In addition, the growth of dissected human anagen hairs in culture in vitro was significantly and dose-dependently inhibited by IL-1 alpha as a consequence of hair bulb degradation. These observations, together with those of other authors in IL-1 alpha transgenic mice evidence the inhibitory role of IL-1 on human hair growth. Therefore, in order to identify individuals with high inflammatory potential in their hair follicle environment, we designed a rapid and simple assay to detect variations in the level of IL-1 alpha production in the overnight supernatant of plucked hairs in culture. We observed that 32.7% of the specimens from the volunteers tested (n = 116) could be considered highly inflammatory in terms of IL-1 alpha production. Altogether, these results suggest that in alopecia androgenetica, hair growth might be negatively influenced by IL-1, directly produced by the outer root sheath keratinocytes. Consequently, identifying the "inflammatory alopecic individual' might be of clinical interest to discriminate among individuals for whom anti-IL-1 strategies might be of therapeutic relevance.
Histamine plays an important part in the cutaneous weal and flare response which underlies many allergic skin conditions. It has a direct effect on the local vasculature to promote vasodilatation and increase microvascular permeability and may also initiate the more widely spread neurogenic flare. Quantification of these responses and studies of the mediator mechanisms underlying them have been limited by the lack of appropriate techniques to investigate them. To address this we have used two relatively new techniques, scanning laser Doppler imaging (LDI) and dermal microdialysis to measure changes in skin blood flow and the release of histamine within the weal and flare, following intradermal injection of histamine or bradykinin. These measurements have been made both in the absence and presence of the H1 receptor blockers cetirizine and loratadine. Scanning LDI of the inflammatory response revealed marked differences in both the development and steady state responses to the intradermal injection of histamine (1-3 mumol/L) and bradykinin (1 mumol/L). The development of the flare and the weal response to both histamine and bradykinin was significantly reduced by cetirizine but not by loratadine. The histamine-induced flare area fell by 57 +/- 4% (mean +/- SEM, n = 10, P < 0.001) after cetirizine and the area of the weal fell by 73 +/- 11% (P < 0.009). Bradykinin-induced inflammatory responses were similarly reduced by cetirizine, the weal by 60 +/- 16% (P < 0.02) and the flare by 61 +/- 4% (P < 0.005). Measurement of histamine concentration in skin using microdialysis, in six subjects, confirmed that histamine levels rose in the dialysate collected from the weal to 310 +/- 16 nmol/L following injection of histamine. Histamine levels also rose following bradykinin injection in some subjects (mean 147 +/- 46 nmol/L, range 18-336). Little increase in histamine concentration was seen in the dialysate from the flare following injection of either histamine or bradykinin. The histamine concentration in dialysate from unprovoked skin was 4.19 +/- 0.75 nmol/L. These data reveal differences in the dermal responses to different mediators when assessed using scanning LDI. They confirm that histamine is released within the weal but not the flare response to the intradermal injection of both histamine and bradykinin and that its effects on the local vasculature to cause the oedematous weal and the axon reflex-mediated flare are significantly attenuated by the H1 antagonist cetirizine and to a lesser extent by the H1 antagonist loratadine.
Tea-tree oil (oil of Melaleuca alternifolia) has recently received much attention as a natural remedy for bacterial and fungal infections of the skin and mucosa. As with most naturally occurring agents, claims of effectiveness have been only anecdotal; however, several published studies have recently demonstrated tea-tree oil's antibacterial activity. This study was conducted to determine the activity of tea-tree oil against 58 clinical isolates: Candida albicans (n = 10), Trichophyton rubrum (n = 8), Trichophyton mentagrophytes (n = 9), Trichophyton tonsurans (n = 10), Aspergillus niger (n = 9), Penicillium species (n = 9), Epidermophyton floccosum (n = 2), and Microsporum gypsum (n = 1). Tea-tree oil showed inhibitory activity against all isolates tested except one strain of E floccosum. These in vitro results suggest that tea-tree oil may be useful in the treatment of yeast and fungal mucosal and skin infections.
Tea tree oil (TTO) is immensely popular for various topical applications. In vitro studies have repeatedly demonstrated that it has antibiotic activity. This article is an attempt to systematically review the evidence from randomised clinical trials for or against effectiveness of external TTO in dermatological conditions.
Six electronic databases were searched. Methodological quality was assessed by Jadad score. Data were extracted and validated in a standardised fashion by two independent reviewers.
Only 4 trials were located. They suggest that TTO may be effective as a treatment of acne and fungal infections. The evidence is promising but by no means compelling. The adverse effects of TTO are usually mild and transient. They mainly consist of allergic reactions.
It is concluded that, so far, there is no compelling evidence to show that TTO is efficacious in any dermatological condition. However, in view of promising findings, TTO deserves to be investigated more closely.