The Effect of Local Application of Tea Tree Oil Adjunctive to Daily Oral Maintenance and Nonsurgical Periodontal Treatment: A Systematic Review and Meta-Analysis of Randomised Controlled Studies.

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.

An upcycled fraction of Melaleuca alternifolia essential oil regenerates the skin through the skin melatonin pathway and improves sleep quality.

BACKGROUND: Sleep is one of the most important factors affecting overall health. During the night, the skin repairs damage caused by daily stresses. Melatonin plays a key role in this process. Toxins are removed, and cellular repair and growth hormone production are increased. Inter alia, this also decreases signs of intrinsic aging. AIMS: The current study was intended to demonstrate the impact of a unique fraction of Melaleuca alternifolia (FMA) essential oil, on sleep and skin quality. METHODS: The effect of FMA was investigated in vitro on skin cells, evaluating its antioxidant and anti-inflammatory properties, and in an ex-vivo study on human skin biopsies treated with FMA following stress induction. In addition, two clinical studies were performed on volunteers with life-style-related sleep complaints. In one study, sleep was measured using a noncontact monitoring device (SleepScore Labs, Max). A second study was conducted to assess skin anti-aging effects. RESULTS: In vitro application of FMA reduced IL-8 and reactive oxygen species (ROS) generation in skin cells. This was confirmed ex vivo through a decrease in inflammatory markers and an increase in antioxidant enzymes after stress induction. Interestingly, FMA also upregulated melatonin-associated genes. Real-world sleep tracking revealed that FMA significantly improved sleep quality, relative to unscented control. In vivo applications also showed a reduction in signs of aging. CONCLUSION: These results provide initial data to suggest that this unique FMA delivers skin anti-aging benefits via a two-pronged mode of action, improving sleep quality, and reducing skin inflammatory and oxidative stress.

[Retrospective surveys on intoxications with essential oils]. / Enquêtes sur la survenue d'intoxications après l'utilisation d'huiles essentielles, comparaison avec les données du CAP d'Angers (2017­2018).

OBJECTIVES: Non-conventional medicines are not devoid of toxicity and it is relevant to establish an inventory of the general public's knowledge of essential oils. The objective is to identify the profile of the victims of a poisoning, the ways of administration and the symptoms as well as the incriminated essential oils. METHODS: Two surveys, for the general public and health professional, were distributed (January-March 2019). In addition, data from the Angers poison control center for the period 2017-2018 were analyzed and compared with the data from our study. RESULTS: Our surveys gathered 623 and 59 answers. The data of the poison control center of Angers counted 741 intoxications. The precautions for use and contra-indications of essential oils are not well known since 5% of the respondents identified them correctly. Our data show that using a mixture increases the risk of intoxication (P<0.02). The most cited essential oils in case of intoxication are Eucalyptus, Tea tree and Lavender. The symptoms mainly concern a cutaneous application (75%) and remain of short duration and without gravity. Concerning the intoxications referenced to the poison control center in Angers, the same essential oils are involved, the oral route is mostly used (70%) and the symptoms listed for 74% of intoxications concern oropharyngeal, ocular, abdominal and skin pain. CONCLUSION: The delivery of essential oils is not harmless and the data obtained both through our surveys and the processing of data from the poison control center of Angers show that they must be used with caution.

Advantages of using toothpaste containing propolis and plant oils for gingivitis prevention and oral cavity hygiene in cleft lip/palate patients.

BACKGROUND: The anti-inflammatory and antibacterial action of preparations used during oral hygiene procedures is particularly important in patients with oral cleft. Few reports have been published assessing the influence of natural products on the state of the oral cavity in patients with oral cleft. The aim of this study was to assess the effect of toothpaste containing Polish propolis and plant oils on oral cavity health in patients with oral cleft treated orthodontically. MATERIALS AND METHODS: A total of 50 patients aged 9-16 years old (20 females, 23 males) were selected and randomly assigned into two groups. Group (A) received toothpaste with Polish propolis, tea tree oil, menthol, and rosemary oil. Group (B) received toothpaste without active ingredients (placebo). A baseline assessment was followed by an oral hygiene index (OHI, debris OHI-D, and calculus OHI-C component) and gingival bleeding index (GBI) after 35 days. The methodology of the oral condition assessment included the presence of cleft malformation as a dysmorphic of the anterior maxilla segment. RESULTS: In group A, improvement in oral cavity hygiene assessed for incisors and molars was found (OHI-T p = 0.011). For the gingival condition, a decrease in the gingival bleeding index - total (GBI-T p = 0.002), as well as for the incisors (GBI-I p = 0.007) and molars (GBI-M p = 0.017) was found. CONCLUSIONS: This research confirms the biological effectiveness of toothpaste with Polish propolis and plant oils. These results may be clinically useful for improving preventative oral care and for control of oral infectious diseases during orthodontic treatment in patients with oral cleft.

Characterization of tea tree oil nanoemulsion and its acute and subchronic toxicity.

Tea tree oil (TTO) is a popular topical use to treat skin infections. However, its poor aqueous solubility and stability have substantially limited its widespread application, including oral administration that might be therapeutic for enteric infections. In this study, mechanical ultrasonic methods were used to prepare TTO nanoemulsion (nanoTTO) with a mean droplet diameter of 161.80 nm ± 3.97, polydispersity index of 0.21 ± 0.01, and zeta potential of -12.33 ± 0.72 mV. The potential toxicity of nanoTTO was assessed by studying the oral median lethal dose (LD50) and repeated 28-day oral toxicity to provide a reference for in vivo application. Results showed that nanoTTO had no phase separation under a centrifugation test and displayed good stability during storage at -20, 4 and 25 °C over 60 days. Repeated-dose 28-day oral toxicity evaluation revealed no significant effects on growth and behavior. Assessments of hematology, clinical biochemistry, and histopathology indicated no obvious adverse effects in mice at 50, 100 and 200 mg/mL. These data suggest that nanoTTO can be considered a potential antimicrobial agent by oral administration due to its inhibitory effect on bacteria and relatively lower toxicity.

Effects of tea tree oil supplementation on growth performance, antioxidant capacity, immune status and microbial community in weaned pigs.

The objective of this study was to determine whether dietary tea tree oil (TTO) supplementation could effectively replace the antibiotics through modulating the antioxidant capacity and intestinal microbiota profile, and then decreasing the diarrhoea incidence and improving the growth performance of weaned pigs. A total of 216 weaned pigs with initial body weights (BW) of 9.19 ± 1.86 kg were randomly allocated to three dietary treatments in a completely randomised design. The dietary treatments included a corn-soybean meal basal diet (CON) without any antibiotics, and two experimental diets formulated by adding 75 mg/kg aureomycin (AGP) or 100 mg/kg TTO into the basal diet, respectively. Pigs fed the TTO diet showed greater gain to feed ratio (p < 0.05) than those fed CON and AGP diets during d 0-14 and d 14-28. Both dietary TTO and AGP supplementation tended to increase the average daily gain of weaned pigs during d 14-28 (p = 0.06) and the overall 28-d period (p = 0.07), and significantly reduced (p < 0.05) the diarrhoea incidence during d 0-14 compared with the CON treatment. In addition, dietary TTO supplementation improved the apparent total tract digestibility of dry matter and ether extract (p < 0.05), and increased (p < 0.05) the propionate and butyrate concentrations in faecal samples of weaned pigs. Moreover, pigs fed the TTO diet showed greater total antioxidant capacity, greater superoxide dismutase and interleukin-10 concentrations, and lower malondialdehyde concentration in serum than those fed the CON diet (p < 0.05). Furthermore, pigs fed the TTO diet demonstrated greater relative abundance of Clostridiaceae_1, while those fed the AGP diet exhibited greater relative abundance of Lactobacillaceae at family level. In conclusion, dietary TTO supplementation could improve growth performance in weaned pigs, which could be mainly attributed to the benefits on nutrient digestibility, antioxidative capacity and microbial community profile.

Evaluation of tea tree oil physicochemical features and its antimicrobial activity against Cutibacterium acnes (Propionibacterium acnes) ATCC 6919 / [Evaluación de las características fisicoquímicas y de la actividad antimicrobiana del aceite del árbol de té contra Cutibacterium acnes (Propionibacterium acnes) ATCC 6919].

Introduction: Tea tree oil is an essential oil recognized for its antimicrobial properties. Objective: To evaluate the composition, features, and antimicrobial effect at 2% v/v, and its minimal inhibitory concentration (MIC) against Cutibacterium acnes (Propionibacterium acnes). Materials and methods: Three different batches of tea tree oil were evaluated. We characterized its chemotype by gas chromatography and its 2% v/v antimicrobial activity against C. acnes by agar diffusion assay (guide M11-A8 CLSI). Results: The three batches of oil had the chemotypes required by the ISO 4730 standard, which indicates that it is a high-quality product. Additionally, they had 30% to 40% of terpinen-4-ol, a compound that favors its antimicrobial activity. Antimicrobial activity against C. acnes for all batches had a concentration-dependent effect with microbial growth inhibitory activity in all assays at 2% v/v. The MIC obtained against C. acnes for all batches was 0.25% v/v. The antimicrobial activity of tea tree oil against this microorganism has been previously reported with a MIC between 0.05% and 1.25% v/v, a range that covers the one obtained in this study. Conclusion: These results show the high quality of the oil and its capacity as an antibacterial agent against C. acnes. New studies should be conducted to confirm its activity and that of its components in isolates of the microorganism from patients with acne vulgaris.

Introducción. El aceite del árbol de té es un aceite esencial reconocido por sus propiedades antimicrobianas. Objetivos. Evaluar la composición, características y efecto antimicrobiano del aceite al 2 % del árbol de té y su concentración inhibitoria mínima (CIM) contra Cutibacterium acnes (Propionibacterium acnes). Materiales y métodos. Se evaluó el quimiotipo en tres lotes diferentes de este aceite mediante cromatografía de gases, así como su actividad antimicrobiana en concentración al 2 % v/v y la CIM contra C. acnes mediante ensayo de difusión en agar (guía M11-A8 CLSI). Resultados. Los lotes evaluados presentaron los quimiotipos ajustados a la norma ISO 4730, lo que indicó la alta calidad del producto. Los lotes contenían de 30 a 40 % de terpinen-4-ol, compuesto que favorece la actividad antimicrobiana, la cual presentó en todos los lotes un efecto dependiente de la concentración contra C. acnes, con una inhibición del crecimiento microbiano en concentración al 2 % v/v en todas las pruebas. La concentración inhibitoria mínima fue de 0,25 % v/v. La actividad antimicrobiana del aceite del árbol de té contra este microorganismo ya ha sido reportada con una concentración inhibitoria mínima entre 0,05 y 1,25 % v/v, rango que cobija la obtenida en este estudio. Conclusiones. Los resultados evidenciaron la gran calidad de este producto y su capacidad como agente antibacteriano contra C. acnes. Se deben hacer estudios con otros aislamientos del microorganismo provenientes de pacientes con acné vulgar para confirmar su actividad general y la de cada uno de sus componentes.

The effect of tea tree oil on dry eye treatment after phacoemulsification cataract surgery: A randomized clinical trial.

PURPOSE: To evaluate the effect of eyelid scrubbing with eye shampoo containing tea tree oil on dry eye disease following phacoemulsification cataract surgery. METHODS: This prospective triple-blinded randomized clinical trial was performed on 62 eyes of 62 patients. Patients were randomly assigned to two groups-(1) treatment group: for 33 patients in the treatment group, artificial tears, topical steroid drops, and eye shampoos with tea tree oil and (2) for 29 patients in the control group, artificial tears, topical steroids, and eye shampoos without tea tree oil were used. In the first and second (after 1 month) follow-up visits, microscopic Demodex examination, refraction, corrected distance visual acuity, the ocular surface disease index score (by the questionnaire), Schirmer test, tear break-up time test, and osmolarity of tears (by TearLab) were recorded in treatment and control groups. RESULTS: The mean age of patients was 66.37 ± 8.83 (range: 37-82) years, of which 49 (79%) were female and 13 (21%) were male. The results showed a significant improvement in tear break-up time test, corrected distance visual acuity, osmolarity, and ocular surface disease index score in both groups (p < 0.05). However, the number of Demodex decreases significantly only in the treatment group after treatment (p <0.001). Tear break-up time, osmolarity, and ocular surface disease index scores in the treatment group were significantly better than the control group (p < 0.05). However, there was no significant difference between the two groups in the pre- and post-Schirmer test results (p > 0.05). CONCLUSION: Eyelid scrubbing with eye shampoo containing tea tree oil is recommended for dry eye treatment after cataract surgery, especially decrease in the number of Demodex.

The efficacy and safety of permethrin 2.5% with tea tree oil gel on rosacea treatment: A double-blind, controlled clinical trial.

BACKGROUND: Rosacea is a chronic skin condition that typically affects the face and it results in redness and inflammation. The main risk factors of this disease are Demodex folliculorum, living in the pilosebaceous units. AIMS: To evaluate the efficacy and safty of permethrin 2.5% in combination with tea tree oil (TTO) topical gel versus placebo on Demodex density (Dd) and clinical manifestation using standard skin surface biopsy (SSSB) in rosacea patients. PATIENT/METHODS: In this double-blind, randomized clinical trial, 47 papulopustular rosacea patients were enrolled, with 35 patients finishing the 12 weeks of treatment. Each patient used permethrin 2.5% with TTO on one side of the face and a placebo on the other, twice daily for 12 weeks. SSSB, photography and clinical rosacea scores according to National Rosacea Society, as well as adverse drug reaction (ADRs) were reported at the baseline, 2nd, 5th, 8th, and 12th weeks. RESULTS: A total of 47 patients were enrolled with papulopustular rosacea, and 35 patients finished the study. The effects of permethrin 2.5% with TTO gel on mite density were significant at week 5, 8, 12 (P value = .001). Clinical features and global assessments showed papules, pustules and nontransient erythema had improvement in drug group after 12 weeks (P values <.05). The improvement of burning and stinging and dry appearance was greater than the placebo gel (P value <.05). Itching in placebo group was significantly more than other group (P value = .002). CONCLUSION: Administration of permethrin 2.5% with TTO gel demonstrated good efficacy and safety in rosacea. This topical gel inhibited the inflammatory effects of rosacea and reduced Demodex mite.

Essential oil-incorporated carbon nanotubes filters for bacterial removal and inactivation.

In this study, essential oils (EO)-incorporated multi-walled carbon nanotubes (MWCNTs) filters were developed for achieving dual functions in effective removing bacteria from aqueous solutions and inactivating bacteria cells captured on the filters. Tea tree essential oil (TTO), lemon essential oil (LEO), and TTO-LEO-mixture were coated on MWCNTs filters with different MWCNTs loadings ranging from 3 mg to 6 mg. MWCNTs filters with 6.0 mg MWCNTs showed complete removal (100%) of E. coli cells from PBS buffer with 6.35 log10 decrease of cell numbers. TTO, LEO, and TTO/LEO Mix (1:1) coatings at the volume of 50 µL on MWCNTs filters achieved bacterial removal rates of >98%, and highly effective inactivation efficiency. TTO coatings had the highest antimicrobial efficacies than LEO and Mix coatings, MWCNTs filters with 50 µL TTO coating showed 100% inhibitory rate of the captured bacteria on the filter surfaces. Those captured but survived cells on filters with less TTO coating (20µL) significantly reduced their salt tolerances to 30 and 40 g/L NaCl in LB agar, and became less salt tolerance with longer incubation time on the filters. The developed TTO-MWCNTs filters had much higher antimicrobial efficacies than the filters with dual functions developed previously.

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.

Melaleuca alternifolia essential oil abrogates hepatic oxidative damage in silver catfish (Rhamdia quelen) fed with an aflatoxin-contaminated diet.

Mycotoxins are secondary metabolites produced by varieties of fungi that contaminate food and feed resources and are capable of inducing a wide range of toxicity. This problem is extensively aggravated due to the increasing replacement of fish meal by plant-derived proteins. Among the mycotoxins, aflatoxins have received a great deal of attention owing to their great prevalence in plant feedstuffs and to the detrimental effects on animals. The objective of this study was to evaluate whether dietary supplementation with tea tree (Melaleuca alternifolia) oil (TTO) would avoid or minimize the negative impacts on silver catfish (Rhamdia quelen) fed with aflatoxins-contaminated diets. Four treatments were tested: control (fish fed with a control diet); AFB (fish fed with a mycotoxin-contaminated diet - 1893 µg kg-1 of AFB1 and 52.2 µg kg-1 AFB2); TTO (fish fed with a control diet + 1 mL kg-1 of TTO), and TTO + AFB (fish fed with a mycotoxin contaminated diet - 2324 µg kg-1 of AFB1 and 43.5 µg kg-1 AFB2 + 1 mL kg-1 of TTO). Diets were tested in three replications and analyzed at days 5 and 10 of dietary intake. Significantly reduced antioxidant enzymes (SOD, GPx, and GST) and increased lipid peroxidation (LOOH) and protein carbonyl (PC) content in plasma and liver, with 16.6% mortality occurrence, were observed in the group fed aflatoxin-contaminated diet. Furthermore, aflatoxins also significantly increased plasmatic and hepatic ROS levels and decreased hepatic antioxidant capacity against peroxyl radical (ACAP) levels. Plasma cortisol levels were not altered by aflatoxicosis, but the intoxication induced hepatose. Notwithstanding, addition of TTO to the groups receiving aflatoxins showed a protective effect, avoiding the increase of ROS, LOOH, and PC levels in plasma and liver. Moreover, TTO treatment ameliorated the aflatoxin-associated liver damage. Thus, TTO supplementation at concentration of 1 mL kg-1 in feed may be used in fish to increase antioxidant status and reduce the negative effects caused by aflatoxins toxicity.

Comparing the in vitro effects of MGO™ Manuka honey and tea tree oil on ocular Demodex viability.

PURPOSE: To compare the in vitro antiparasitic effects of MGO™ Manuka honey and tea tree oil against ocular Demodex. METHODS: Fifty-two viable Demodex mites were acquired from the epilated eyelashes of 9 participants with blepharitis and symptomatic dry eye. Viable mites were randomised to one of five treatment groups: cyclodextrin-complexed and uncomplexed Manuka Honey, 100% and 50% tea tree oil, and no treatment. Following treatment application, mite viability was assessed for 240 min, based on limb and body movement and/or the development of a crenated/translucent appearance. Kaplan-Meier survival analysis was then performed. RESULTS: The log-rank test demonstrated a significant treatment effect on the survival distribution of Demodex mites (p < 0.001). Bonferroni-corrected post-hoc pairwise analysis showed that all treatments except for uncomplexed honey effected lower survival probabilities than the untreated group (all p < 0.001). Among the four treatments, survival probabilities were lowest with 100% tea tree oil (all p < 0.001), and highest with uncomplexed honey (all p ≤ 0.001). No difference was observed between complexed honey and 50% tea tree oil (p = 0.81). CONCLUSIONS: The in vitro efficacy of cyclodextrin-complexed Manuka honey was comparable with 50% tea tree oil, an established treatment for ocular Demodex. The findings support future clinical trials investigating the therapeutic effects of complexed honey in demodectic blepharitis patients.

Delivery of adapalene using a novel topical gel based on tea tree oil nano-emulsion: Permeation, antibacterial and safety assessments.

The aim of present study was to design and optimize 0.1% adapalene loaded nano-emulsion to improve the drug efficacy and increase its user compliance. Effect of type and concentration of surfactants was studied on size of 0.1% adapalene loaded nano-emulsion. Optimized formulation was then evaluated for particle size, polydispersity index, morphology, viscosity, and pH. Subsequently, 1% carbopol® 934 was incorporated to the optimized formulation for preparation of its gel form. The efficacy and safety of 0.1% adapalene loaded nano-emulsion gel was assessed compared to marketed gel containing 0.1% adapalene. In-vitro studies showed that adapalene permeation through the skin was negligible in both adapalene loaded nano-emulsion gel and adapalene marketed gel. Furthermore, drug distribution studies in skin indicated higher retention of adapalene in the dermis in adapalene loaded nano-emulsion gel compared with adapalene marketed gel. Antibacterial activity against Propionibacterium acnes showed that adapalene loaded nano-emulsion is effective in reducing minimum inhibitory concentration of the formulation in comparison with tea tree oil nano-emulsion, and pure tea tree oil. In vivo skin irritation studies showed absence of irritancy for adapalene loaded nano-emulsion gel. Also, blood and liver absorption of the drug, histological analysis of liver and liver enzyme activity of rats after 90 days' treatment were investigated. No drug was detected in blood/liver which in addition to an absence of any adverse effect on liver and enzymes showed the potential of adapalene loaded nano-emulsion gel as a novel carrier for topical delivery of adapalene.

Promising Antibacterial Effects of Silver Nanoparticle-Loaded Tea Tree Oil Nanoemulsion: a Synergistic Combination Against Resistance Threat.

Highly resistant pathogens may be developed in patients with immune disorders after prolonged exposure to antibiotics, a growing threat worldwide. In order to overcome these problems, this study introduces a new class of engineered nanosystems comprising of tea tree oil nanoemulsion (TTO NE) loaded with Ag nanoparticles (NPs). Silver shows a strong toxicity towards a wide range of microorganisms. Also, TTO NE could be employed as a promising and safe antimicrobial agent for local therapies of bacterial infections. The nanosystem was prepared by low-energy method. Mean droplet size of the NE was found to be 17.7 nm. Results of the antibacterial assays showed promising ability of the designed nanosystem for eradication of Gram-positive and Gram-negative bacteria (95%). Also, it was shown that introducing colloidal Ag NPs to the TTO NE exerted a synergistic effect against Escherichia coli (FIC 0.48) while only an additive effect was observed against Staphylococcus aureus (FIC 0.75). The antibacterial effects of TTO NE+Ag NPs together with their compatibility with human cells can present them as a suitable candidate to fight against the antibacterial resistance threat.

Consumer exposure to certain ingredients of cosmetic products: The case for tea tree oil.

Reliable exposure data are essential to evaluate the safety of ingredients in cosmetics. The study reported here was carried out on behalf of the Australian Tea Tree Industry Association in order to support safety assessment of TTO in consumer cosmetic products. Data regarding the use of TTO-containing cosmetic products were collected through a web-survey among 2535 qualified users of validated TTO-containing cosmetics in 5 European countries. Data regarding the percentage of TTO present in the individual products (TTO-inclusion) were collected from the suppliers of those products. Beyond TTO exposure-measures there were several significant findings: One is a special "TTO-effect" for several categories of TTO-containing cosmetic products showing a positive correlation between consumers' strength of TTO-orientation and frequency of product use, combined with a negative correlation between frequency of product use and amount of product used per application. Another is significant differences regarding the intensity of product use between TTO-containing cosmetics and respective types of products in general. Thus it seems not to be appropriate to evaluate the toxicological safety of certain ingredients of cosmetic products from exposure data on "generic" types of cosmetic products.

Pulmonary delivery of tea tree oil-ß-cyclodextrin inclusion complexes for the treatment of fungal and bacterial pneumonia.

OBJECTIVES: Bacterial pneumonia is a common cause of death worldwide. Tea tree oil (TTO) is a potent antimicrobial natural product, which is formulated in dry powder inhalers (DPIs) for the treatment of fungal and bacterial pneumonia. METHODS: Tea tree oil-ß-cyclodextrin inclusion complexes (TTO-ß-CD) were prepared and characterized. Aerodynamic properties of TTO-ß-CD powders were measured. The rat models of fungal (Candida albicans) and bacterial (Acinetobacter baumannii) pneumonia were prepared. Saline, TTO, TTO-ß-CD and the positive drug (fluconazole or penicillin) were directly delivered to the rat lungs. Pathological and biological assays were conducted. KEY FINDINGS: Tea tree oil-ß-CD powders had an appropriate aerodynamic diameter of 5.59 µm and the fine particle fraction of 51.22%, suitable for pulmonary delivery. TTO-ß-CD showed higher and similar antipneumonic effects on the rat models than fluconazole and penicillin, respectively. The effects of TTO-ß-CD were higher than TTO alone. The antipneumonic mechanisms involved blocking the recruitment of leucocytes and neutrophils, eliminating the microbes, downregulating pro-inflammatory cytokines (including tumour necrosis factor-α, interleukin-1ß and interleukin-6), suppressing cyclooxygenase 2 expression, and further reducing lung injury. CONCLUSIONS: Inhaled TTO-ß-CD powders have the advantages of portability, high stability, self-administration, high lung deposition and good antipneumonic effect. It is a promising DPI for the treatment of fungal and bacterial pneumonia.

Hypolipidemic effect of Youcha in hyperlipidemia rats induced by high-fat diet.

Youcha is a novel tea drink from the northeast of Guangxi. This study aimed to investigate the hypolipidemic properties of Youcha in high-fat induced hyperlipidemic Sprague-Dawley (SD) rats. After designing the model, rats were randomly divided into six groups (n = 10): normal diet (NMD) group, high-fat diet (HFD) group, Xuezhikang (120 mg kg-1 d-1) (HFD+P) group and Youcha (150, 750 or 1500 mg kg-1 d-1) (HFD+L, HFD+M or HFD+H) groups. Youcha comprises tea polyphenols (1.51 g per 100 g), caffeine (34.80 mg per 100 g) and other functional compounds. To evaluate the lipid-lowering effects of Youcha, weight of the body, liver and fat, fat index, lipid metabolism, antioxidant properties and liver damage indices were examined. In addition, the activities of some enzymes in serum and liver tissue were examined to preliminarily study their possible mechanism. The results reveal that Youcha tends to reduce body weight, liver weight, fat index, total cholesterol (TC) and triglyceride (TG) contents, low-density lipoprotein cholesterol (LDL-C), atherogenic index (AI), malondialdehyde (MDA), aspartate aminotransferase (AST) and alanine aminotransferase (ALT), and increase high-density lipoprotein cholesterol (HDL-C), superoxide dismutase (SOD) and glutathione peroxidase (GPx) relative to the HFD group. The hypolipidemic effect was partly due to the regulation of fatty acid synthetase (FAS) and lipase (LPS) rather than lipoprotein lipase (LPL) to decrease TG markedly. These findings suggest that Youcha could be potentially used to remedy hyperlipidemia and is hence worthy of promotion as a tea drink.

The Effect of Polyhexanide, Octenidine Dihydrochloride, and Tea Tree Oil as Topical Antiseptic Agents on In Vivo Microcirculation of the Human Skin: A Noninvasive Quantitative Analysis.

BACKGROUND: Antiseptics are indispensable for wound management and should focus not only on the efficacy in reducing the bacterial burden but also on how much they interfere in wound healing. In this study, the authors analyzed the direct effect of topical antiseptic agents on the microcirculation of intact human skin. METHODS: The perfusion dynamics were assessed before, and 10 minutes after, the volunteers' fingers of the right hand (n = 20) were immersed in the following solutions - octenidine dihydrochloride, polyhexanide, tea tree oil, and saline solution. The authors used the Oxygen to See (LEA Medizintechnik GmbH, Giessen, Germany) diagnostic device for noninvasive determination of oxygen supply in microcirculation of blood perfused tissues, which combines a laser light to determine blood flow, as well as white light to determine hemoglobin oxygenation and the relative amount of hemoglobin. RESULTS: Tea tree oil (÷19.0%) (B. Braun Melsungen AG, Melsungen, Germany) and polyhexanide (÷12.4%) (Lavanid, Serag Wiessner GmbH, Naila, Germany) caused a significant increase in blood flow compared to the negative control (-25.6%). Octenidine (Octenisept, Schülke & Mayr GmbH, Norderstedt, Germany) showed a nonsignificant trend towards an increase in blood flow (÷7.2%). There were alterations in the values of hemoglobin oxygenation and the relative amount of hemoglobin, but these were not significant. CONCLUSION: Perfusion is an important factor for wound healing. Therefore, it might be advantageous if antiseptic agents would increase blood flow. Tea tree oil and polyhexanide have a positive effect on skin blood flow and can therefore be used especially in critically perfused wounds, provided the adverse reactions and the antimicrobial efficacy are comparable.

Melaleuca alternifolia anthelmintic activity in gerbils experimentally infected by Haemonchus contortus.

Gastrointestinal parasites are one of the biggest health problems faced in sheep, mainly due to their pathogenicity and resistance to drugs used to control these parasites. Thus, the following study aimed to assess the anthelmintic efficacy of Melaleuca alternifolia against Haemonchus contortus in gerbils (Meriones unguiculatus) experimentally infected. Three treatments were tested: M. alternifolia essential oil, popularly known as tea tree oil (TTO), a solid lipid nanocarrier made with essential oil of Melaleuca (nanoTTO), and terpinen-4-ol (terp-4-ol). In vivo studies were performed by determining the mean worm burden of H. contortus in gerbils TTO (0.75 mL/kg); nanoTTO (0.5 mL/kg) and terp-4-ol (0.5 mL l/kg) were able to reduce 46.36%; 48.64%, and 43.18% worm burden, respectively. H. contortus increased alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, as demonstrated by liver injury. It was found that the TTO, nanoTTO, and terp-4-ol were not toxic to liver and kidneys since hepatic and renal functions were not affected. Moreover, terp-4-ol was able to prevent increased levels of seric AST and ALT in infected animals, indicating a hepatoprotective effect. Thus, our results indicate that TTO, nanoTTO, and terp-4-ol are safe and efficient against H. contortus infection in gerbils, and possibly the terp-4-ol may be considered the compound present in the Melaleuca alternifolia responsible for parasitic action against H. contortus.