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At least 217 records · Page 12Linked to original sources
PubMed2005

Effects of a topical essential oil-containing formulation on biofilm-forming coagulase-negative staphylococci.

AIMS: To evaluate the antimicrobial effects of Polytoxinol (PT), a topical essential oil-based formulation, against biofilm positive strains of coagulase-negative staphylococci. METHODS AND RESULTS: Using a microtitre plate assay we measured inhibitory effects for PT against a selection of biofilm-forming clinical isolates of coagulase-negative staphylococci. Susceptibility varied considerably (MIC = 0.6-20 000 ppm). For the most tolerant clinical isolate (Staphylococcus warneri) biofilm growth was inhibited by a 32-fold lower PT concentration than planktonic growth. This inhibition of biofilm development, which was not observed with the other test isolates, was related to an inhibition of the initial phase of S. warneri cell adherence to the polystyrene surface. CONCLUSION: The antimicrobial efficacy of PT was verified against clinical isolates of coagulase-negative staphylococci in vitro. PT was able to inhibit biofilm formation in the most tolerant isolate at sub-inhibitory concentrations. SIGNIFICANCE AND IMPACT OF THE STUDY: These observations indicate that an ability to prevent biofilm formation, independently of effects on cell viability may contribute to the in vivo topical efficacy of essential oils.

Anti-Infective Agents, Local↗
PubMed2004

Anti-inflammatory effects of Melaleuca alternifolia essential oil on human polymorphonuclear neutrophils and monocytes.

OBJECTIVE AND DESIGN: The fungicidal and bactericidal actions of the essential oil (EO) of Melaleuca alternifolia seem well established, but their anti-inflammatory and anti-oxidative effects remain unclear. In this study, we investigated in vitro the possible role of whole M. alternifolia EO as a modulator of the oxidative response, i.e. reactive oxygen species (ROS) production, of leukocytes (monocytes and polymorphonuclear neutrophils (PMNs)) in humans. METHODS: Whole blood leukocytes from healthy human volunteers (n = 7), isolated from erythrocytes by haemolytic shock, were incubated for 30 min with M. alternifolia EO (0-0.1%) to determine their ROS production by flow cytometry with or without stimulation of cells. We compared the effects of 3 different stimulating agents acting differently on transductional pathways to stimulate the ROS production: a phorbol ester (PMA), formyl-methionyl-leucyl-phenylalanine (fMLP) and opsonised zymosan (OZ). RESULTS: As attested by the Krüskall-Wallis test, M. alternifolia EO at 0.1% directly stimulated ROS production by PMNs (x 8.7 vs. 0% EO, p < 0.05) and increased the intracellular ROS produced by monocytes. Whichever the stimulating agent used (PMA, fMLP or OZ), M. alternifolia EO decreased the intracellular ROS production at the dilution of 0.1% by PMNs and monocytes, more so with PMNs. CONCLUSION: M. alternifolia EO may be both a direct active mediator of the bactericidal action of the circulating leukocytes and may be efficient in protecting the organism from an excess of ROS, through an anti-oxidant and radical scavenging activity.

Anti-Inflammatory Agents↗
PubMed2001

Flavonoids of Melaleuca quinquenervia.

From the leaves of Melaleuca quinquenervia (Clav.) S. T. Blake, the new flavonoid 5,7,3',4'-tetrahydroxyflavone 2'-O-beta-D-glucopyranuronide, as well as eight known flavonol glycosides have been isolated and characterized. The structures were established by chromatography, chemical degradation and UV spectroscopy and confirmed by ESI-MS and NMR spectroscopy. This is the first report on the isolation and identification of these flavonoids in the genus Melaleuca.

Flavonoids↗
PubMed2003

Monoterpenoid accumulation in 1,8-cineole, terpinolene and terpinen-4-ol chemotypes of Melaleuca alternifolia seedlings.

Individual leaves of the three most common chemotypes of Melaleuca alternifolia were examined both quantitatively and qualitatively for volatile constituents from the emergence of the first true leaves, through to 6-week-old tenth leaf set material. The 1,8-cineole and terpinolene chemotypes were investigated and compared with the recently reported commercial terpinen-4-ol chemotype. The 1,8-cineole chemotype was found to accumulate 1,8-cineole and associated p-menthanes limonene, terpinen-4-ol and alpha-terpineol gradually with increasing leaf set number. As with the terpinen-4-ol variety, higher than expected concentrations of the pinenes and terpinolene were found only in the early leaf sets. The terpinolene variety showed two stages of terpinolene accumulation, the first at leaf sets 2-3 similar to the unexpected biosynthesis of terpinolene in the terpinen-4-ol chemotype and the second at leaf sets 8-9 which is characteristic of the terpinolene variety.

Cyclohexane Monoterpenes↗
PubMed2000

Cooling the burn wound: evaluation of different modalites.

A study was undertaken to investigate the cooling and healing effect of different modalities: Melaleuca Alternifolia Hydrogel (Levtrade International (Pty) Ltd.) was compared with tap water as a coolant following application onto a fresh deep partial thickness hot water burn in a porcine model. Four identical circular scalds were created on the backs of 10 pigs. One wound was not treated and served as a control. The other 3 wounds were either cooled with tap water (15 degrees C) or had Melaleuca Hydrogel dressing applied immediately, or after a 30 min delay. Intradermal temperatures were monitored in all wounds: preburn, during the burn and at regular intervals for 1 h. The wounds were biopsied for histological assessment. These samples were repeated at 24 h and 3 weeks. The mean decrease in final temperature at 1 h was in comparison to the preburn temperature; control +0.44 degrees C (i.e. a temperature increase); water -7.82 degrees C; Melaleuca Hydrogel -3.87 degrees C; Melaleuca Hydrogel after 30 min delay -2.67 degrees C. Clinical and histological assessment at 21 days indicated more rapid healing in both the Melaleuca Hydrogel and water-cooled burns compared with the untreated controls. Effective cooling of the burn wound and an increased rate of wound healing was achieved by both repeated tap water compresses and by immediate or delayed application of Melaleuca Hydrogel. Cooling is an effective means to reduce tissue damage and increase wound healing.

Administration, Topical↗
PubMedDate not supplied

Efficacy of alcohol-based and alcohol-free melaleuca oral solution for the treatment of fluconazole-refractory oropharyngeal candidiasis in patients with AIDS.

PURPOSE: To evaluate the efficacy of alcohol-based and alcohol-free melaleuca oral solution in patients with AIDS and fluconazole-refractory oropharyngeal candidiasis. METHOD: We performed a prospective, single-center, open-label study in a university-based inner city HIV/AIDS clinic. The study included 27 patients with AIDS and oral candidiasis clinically refractory to fluconazole. Patients were randomized 1:1 to receive either alcohol-based or alcohol-free melaleuca oral solution four times daily for 2-4 weeks. Thirteen patients were enrolled into cohort 1, and 14 patients were enrolled into cohort 2. The main outcome measure was resolution of clinical lesions of oral candidiasis. Evaluations were performed at 2 and 4 weeks for clinical signs and symptoms of oral candidiasis and quantitative yeast cultures. RESULTS: All C. albicans isolates showed some degree of in vitro resistance to fluconazole. Overall, using a modified intent-to-treat analysis, 60% of patients demonstrated a clinical response to the melaleuca oral solution (7 patients cured and 8 patients clinically improved) at the 4-week evaluation. CONCLUSION: Both formulations of the melaleuca oral solution appear to be effective alternative regimens for patients with AIDS suffering from oropharyngeal candidiasis refractory to fluconazole.

Acquired Immunodeficiency Syndrome↗
PubMed2003

A yoga teacher with persistent cheilitis.

This is a depiction of an evolving case report right from its presentation to the physician and its documentation and further sharing of it through the net via e-mails and evidence-based-health@jiscmail.ac.uk as well as other colleagues.

Anti-Infective Agents, Local↗
PubMed2005

Recurrent vulvovaginitis candidiasis; an overview of traditional and alternative therapies.

Vulvovaginitis is a common inflammatory condition that can significantly disrupt a woman's life. The term vulvovaginitis actually encompasses a variety of inflammatory lower gential tract disorders that may be secondary to infection, irritation, allergy or systemic disease (Table 1). This article focuses on candida-caused vulvovaginitis, a condition known as vulvovaginitis candidiasis. Approximately 75% of U.S. women expreience vulvovaginitis candidiasis during thier reproductive years. Between 40% and 50% of these women have recurrent episodes, and 5% to 8% experience chronic candida infections. Approximately 3 million women have recurrent candidial infections. The prevalence of vulvovaginitis candiasis is expected to rise due to the growing number of non-C albicans species (which are immune to most antifungal medcationa) and as a result of more widespread antifungal resistance.

Anti-Infective Agents, Local↗
PubMed2001

Adverse and beneficial effects of plant extracts on skin and skin disorders.

Plants are of relevance to dermatology for both their adverse and beneficial effects on skin and skin disorders respectively. Virtually all cultures worldwide have relied historically, or continue to rely on medicinal plants for primary health care. Approximately one-third of all traditional medicines are for treatment of wounds or skin disorders, compared to only 1-3% of modern drugs. The use of such medicinal plant extracts for the treatment of skin disorders arguably has been based largely on historical/anecdotal evidence, since there has been relatively little data available in the scientific literature, particularly with regard to the efficacy of plant extracts in controlled clinical trials. In this article therefore, adverse and beneficial aspects of medicinal plants relating to skin and skin disorders have been reviewed, based on recently available information from the peer-reviewed scientific literature. Beneficial aspects of medicinal plants on skin include: healing of wounds and burn injuries (especially Aloe vera); antifungal, antiviral, antibacterial and acaricidal activity against skin infections such as acne, herpes and scabies (especially tea tree (Melaleuca alternifolia) oil); activity against inflammatory/immune disorders affecting skin (e.g. psoriasis); and anti-tumour promoting activity against skin cancer (identified using chemically-induced two-stage carcinogenesis in mice). Adverse effects of plants on skin reviewed include: irritant contact dermatitis caused mechanically (spines, irritant hairs) or by irritant chemicals in plant sap (especially members of the Ranunculaceae, Euphorbiaceae and Compositae plant families); phytophotodermatitis resulting from skin contamination by plants containing furocoumarins, and subsequent exposure to UV light (notably members of the Umbelliferae and Rutaceae plant families); and immediate (type I) or delayed hypersensitivity contact reactions mediated by the immune system in individuals sensitized to plants or plant products (e.g. peanut allergy, poison ivy (Toxicodendron) poisoning).

Burns↗
PubMed1999

Microsatellite variation and assessment of genetic structure in tea tree (Melaleuca alternifolia-Myrtaceae).

Analysis of five microsatellite loci in 500 Melaleuca alternifolia individuals produced 98 alleles that were useful for population genetic studies. Considerable levels of observed heterozygosity were recorded (HO = 0.724), with approximately 90% of the variability being detected within populations. A low level of selfing (14%) was suggested to be the principal cause of excess homozygosity in a number of populations (overall FIS = 0.073). This study showed low levels of inbreeding in certain populations as well as a significant isolation-by-distance model. Only two groups of populations (Queensland and New South Wales) constituted different genetic provenances as a result of geographical isolation. The M. alternifolia data suggest that microsatellite loci did not always arise by a stepwise mutation process but that larger jumps in allele size may be involved in their evolution.

Australia↗
PubMed1998

A new method for determining the minimum inhibitory concentration of essential oils.

A new microdilution method has been developed for determining the minimum inhibitory concentration (MIC) of oil-based compounds. The redox dye resazurin was used to determine the MIC of a sample of the essential oil of Melaleuca alternifolia (tea tree) for a range of Gram-positive and -negative bacteria. Use of 0.15% (w/v) agar as a stabilizer overcame the problem of adequate contact between the oil and the test bacteria and obviated the need to employ a chemical emulsifier. A rapid version of the assay was also developed for use as a screening method. A comparison of visual and photometric reading of the microtitre plates showed that results could be assessed without instrumentation; moreover, if the rapid assay format was used, rigorous asepsis was not necessary. Accuracy of the resazurin method was confirmed by plate counting from microwells and MIC values were compared with results obtained using an agar dilution assay. The MIC results obtained by the resazurin method were slightly lower than those obtained by agar dilution.

Gram-Negative Bacteria↗
PubMed2000

Natural variation in the essential oil content of Melaleuca alternifolia Cheel (Myrtaceae).

The composition and yield of oil in 615 trees representing the natural populations of Melaleuca alternifolia, or tea tree, was investigated. A sixth distinct oil chemotype was identified. Of the six chemotypes, one chemotype is dominated by terpinen-4-ol, one by 1,8-cineole, one by terpinolene and the remaining three chemotypes are all dominated by 1,8-cineole and differ in either terpinen-4-ol or terpinolene content. Whilst most chemotypes are present throughout the distribution range, a definite correspondence of oil types with geographic location was found. Terpinen-4-ol types predominate in and around the Bungawalbin basin in the Casino area of northern New South Wales (NSW), high 1,8-cineole types predominate toward the southern end of the distribution around Grafton and terpinolene types predominate in southern Queensland. Preliminary formulae have been developed to allow comparisons of oil data obtained by steam distillation with a static headspace gas chromatography method.

Journal Article↗