The Experts below are selected from a list of 5310 Experts worldwide ranked by ideXlab platform
Thomas V Riley - One of the best experts on this subject based on the ideXlab platform.
-
role of the mexab oprm efflux pump of pseudomonas aeruginosa in tolerance to tea tree Melaleuca alternifolia oil and its monoterpene components terpinen 4 ol 1 8 cineole and α terpineol
Applied and Environmental Microbiology, 2008Co-Authors: Chelsea J Papadopoulos, Christine F Carson, Barbara J Chang, Thomas V RileyAbstract:Using a series of efflux mutants of Pseudomonas aeruginosa, the MexAB-OprM pump was identified as contributing to this organism's tolerance to the antimicrobial agent tea tree (Melaleuca alternifolia) oil and its monoterpene components terpinen-4-ol, 1,8-cineole, and α-terpineol. These data show that a multidrug efflux system of P. aeruginosa can extrude monoterpenes and related alcohols.
-
a review of the toxicity of Melaleuca alternifolia tea tree oil
Food and Chemical Toxicology, 2006Co-Authors: Katherine A Hammer, Christine F Carson, Thomas V Riley, Jesper Bo NielsenAbstract:The essential oil of Melaleuca alternifolia, also known as tea tree or Melaleuca oil, is widely available and has been investigated as an alternative antimicrobial, anti-inflammatory and anti-cancer agent. While these properties are increasingly well characterised, relatively limited data are available on the safety and toxicity of the oil. Anecdotal evidence from almost 80 years of use suggests that the topical use of the oil is relatively safe, and that adverse events are minor, self-limiting and occasional. Published data indicate that TTO is toxic if ingested in higher doses and can also cause skin irritation at higher concentrations. Allergic reactions to TTO occur in predisposed individuals and may be due to the various oxidation products that are formed by exposure of the oil to light and/or air. Adverse reactions may be minimised by avoiding ingestion, applying only diluted oil topically and using oil that has been stored correctly. Data from individual components suggest that TTO has the potential to be developmentally toxic if ingested at higher doses, however, TTO and its components are not genotoxic. The limited ecotoxicity data available indicate that TTO is toxic to some insect species but more studies are required.
-
safety efficacy and provenance of tea tree Melaleuca alternifolia oil
Contact Dermatitis, 2001Co-Authors: Christine F Carson, Thomas V RileyAbstract:The identity, sources and composition of tea tree (Melaleuca alternifolia) oil are discussed, and earlier errors in the literature indicated. Reports of both therapeutic and allergenic effects are reviewed.
-
broth micro dilution method for determining the susceptibility of escherichia coli and staphylococcus aureus to the essential oil of Melaleuca alternifolia tea tree oil
Microbios, 1995Co-Authors: Christine F Carson, Katherine A Hammer, Thomas V RileyAbstract:A broth micro-dilution method was used to examine the susceptibility of Escherichia coli (n = 110) and Staphylococcus aureus (n = 105) to the essential oil of Melaleuca alternifolia (tea tree oil). The detergent Tween 80 was used successfully to enhance the solubility of tea tree oil in the test medium. The MIC90 of tea tree oil for E. coli was 0.25% while for S. aureus it was 0.50%.
-
antimicrobial activity of the essential oil of Melaleuca alternifolia
Letters in Applied Microbiology, 1993Co-Authors: Christine F Carson, Thomas V RileyAbstract:Melaleuca alternifolia has been used for medical purposes since Australia was colonized in 1788. Melaleuca alternifolia is commonly called tea tree, although this vernacular name is also given to many other species in the Leptospermum and Melaleuca genera. A small tree, it grows up to 5 m in height, has papery bark and narrow, tapered leaves up to 20 mm in length and flowers in summer. Melaleuca alternifolia is unique to Australia and its natural habitat is a relatively small area around the Clarence and Richmond rivers in the north‐east coastal area of New South Wales where the terrain is generally low lying and swampy. The essential oil of M. alternifolia, or tea tree oil. has enjoyed increased medicinal use in recent years. It is a pale yellow viscous liquid with a distinctive pungent odour and is composed of a complex mixture of monoterpenes, 1‐terpinen‐4‐ol, cineole and other hydrocarbons (Pena 1962).
Christine F Carson - One of the best experts on this subject based on the ideXlab platform.
-
role of the mexab oprm efflux pump of pseudomonas aeruginosa in tolerance to tea tree Melaleuca alternifolia oil and its monoterpene components terpinen 4 ol 1 8 cineole and α terpineol
Applied and Environmental Microbiology, 2008Co-Authors: Chelsea J Papadopoulos, Christine F Carson, Barbara J Chang, Thomas V RileyAbstract:Using a series of efflux mutants of Pseudomonas aeruginosa, the MexAB-OprM pump was identified as contributing to this organism's tolerance to the antimicrobial agent tea tree (Melaleuca alternifolia) oil and its monoterpene components terpinen-4-ol, 1,8-cineole, and α-terpineol. These data show that a multidrug efflux system of P. aeruginosa can extrude monoterpenes and related alcohols.
-
a review of the toxicity of Melaleuca alternifolia tea tree oil
Food and Chemical Toxicology, 2006Co-Authors: Katherine A Hammer, Christine F Carson, Thomas V Riley, Jesper Bo NielsenAbstract:The essential oil of Melaleuca alternifolia, also known as tea tree or Melaleuca oil, is widely available and has been investigated as an alternative antimicrobial, anti-inflammatory and anti-cancer agent. While these properties are increasingly well characterised, relatively limited data are available on the safety and toxicity of the oil. Anecdotal evidence from almost 80 years of use suggests that the topical use of the oil is relatively safe, and that adverse events are minor, self-limiting and occasional. Published data indicate that TTO is toxic if ingested in higher doses and can also cause skin irritation at higher concentrations. Allergic reactions to TTO occur in predisposed individuals and may be due to the various oxidation products that are formed by exposure of the oil to light and/or air. Adverse reactions may be minimised by avoiding ingestion, applying only diluted oil topically and using oil that has been stored correctly. Data from individual components suggest that TTO has the potential to be developmentally toxic if ingested at higher doses, however, TTO and its components are not genotoxic. The limited ecotoxicity data available indicate that TTO is toxic to some insect species but more studies are required.
-
safety efficacy and provenance of tea tree Melaleuca alternifolia oil
Contact Dermatitis, 2001Co-Authors: Christine F Carson, Thomas V RileyAbstract:The identity, sources and composition of tea tree (Melaleuca alternifolia) oil are discussed, and earlier errors in the literature indicated. Reports of both therapeutic and allergenic effects are reviewed.
-
broth micro dilution method for determining the susceptibility of escherichia coli and staphylococcus aureus to the essential oil of Melaleuca alternifolia tea tree oil
Microbios, 1995Co-Authors: Christine F Carson, Katherine A Hammer, Thomas V RileyAbstract:A broth micro-dilution method was used to examine the susceptibility of Escherichia coli (n = 110) and Staphylococcus aureus (n = 105) to the essential oil of Melaleuca alternifolia (tea tree oil). The detergent Tween 80 was used successfully to enhance the solubility of tea tree oil in the test medium. The MIC90 of tea tree oil for E. coli was 0.25% while for S. aureus it was 0.50%.
-
antimicrobial activity of the essential oil of Melaleuca alternifolia
Letters in Applied Microbiology, 1993Co-Authors: Christine F Carson, Thomas V RileyAbstract:Melaleuca alternifolia has been used for medical purposes since Australia was colonized in 1788. Melaleuca alternifolia is commonly called tea tree, although this vernacular name is also given to many other species in the Leptospermum and Melaleuca genera. A small tree, it grows up to 5 m in height, has papery bark and narrow, tapered leaves up to 20 mm in length and flowers in summer. Melaleuca alternifolia is unique to Australia and its natural habitat is a relatively small area around the Clarence and Richmond rivers in the north‐east coastal area of New South Wales where the terrain is generally low lying and swampy. The essential oil of M. alternifolia, or tea tree oil. has enjoyed increased medicinal use in recent years. It is a pale yellow viscous liquid with a distinctive pungent odour and is composed of a complex mixture of monoterpenes, 1‐terpinen‐4‐ol, cineole and other hydrocarbons (Pena 1962).
Ilkwon Park - One of the best experts on this subject based on the ideXlab platform.
-
fumigant and contact toxicity of myrtaceae plant essential oils and blends of their constituents against adults of german cockroach blattella germanica and their acetylcholinesterase inhibitory activity
Pesticide Biochemistry and Physiology, 2013Co-Authors: Hwajeong Yeom, Jaesoon Kang, Sungwoong Kim, Ilkwon ParkAbstract:Abstract Fumigant and contact toxicities of 11 Myrtaceae plant essential oils and their constituents against adult male and female Blattella germanica were evaluated. Of 11 Myrtaceae plant essential oils, Eucalyptus polybractea, Eucalyptus smithii, Eucalyptus radiata, Eucalyptus dives, Eucalyptus globulus, and Melaleuca uncinata, showed 100% fumigant toxicity against adult male German cockroaches at a concentration of 7.5 mg/liter air concentration. In contact toxicity tests, E. polybractea, E. smithii, E. radiata, E. dives, E. globulus, Melaleuca dissitiflora, and M. uncinata produced strong insecticidal activity against adult male and female German cockroaches. Of the essential oil constituents, terpinolene, α-terpinene, and terpinen-4-ol demonstrated strong fumigant toxicity against adult male and female B. germanica. Eugenol, isoeugenol, methyl eugenol, and terpinen-4-ol showed strong contact toxicity against adult male B. germanica. The toxicity of the constituent blends identified from M. dissitiflora essential oils indicated that terpinen-4-ol were major contributor to the fumigant activity or contact toxicity of the artificial blend. Only isoeugenol exhibited inhibition activity against male acetylcholinesterase. IC50 values of isoeugenol were 0.22 mg/mL against male acetylcholinesterase.
-
larvicidal activity of myrtaceae essential oils and their components against aedes aegypti acute toxicity on daphnia magna and aqueous residue
Journal of Medical Entomology, 2011Co-Authors: Hyemi Park, Junheon Kim, Kyusik Chang, Byungseok Kim, Yujung Yang, Gilhah Kim, Sangchul Shin, Ilkwon ParkAbstract:ABSTRACT The larvicidal activity of 11 Myrtaceae essential oils and their constituents was evaluated against Aedes aegypti L. Of the 11, Melaleuca linariifolia Sm., Melaleuca dissitiflora F. Muell., Melaleuca quinquenervia (Cav.) S. T. Blake, and Eucalyptus globulus Labill oils at 0.1 mg/ml exhibited ≥80% larval mortality. At this same concentration, the individual constituents tested, allyl isothiocyanate, α-terpinene, p-cymene, (+)-limonene, (-)-limonene, γ-terpinene, and (E)-nerolidol, resulted in ≥95% mortality. We also tested the acute toxicity of these four active oils earlier mentioned and their constituents against Daphnia magna Straus. M. linariifolia and allyl isothiocyanate was the most toxic to D. magna. Two days after treatment, residues of M. dissitiflora, M. linariifolia, M. quinquenervia, and E. globulus oils in water were 55.4, 46.6, 32.4, and 14.8%, respectively. Less than 10% of allyl isothiocyanate, α-terpinene, p-cymene, (-) -limonene, (+) -limonene, and γ-terpinene was detected in th...
-
Larvicidal Activity of Myrtaceae Essential Oils and Their Components Against Aedes aegypti, Acute Toxicity on Daphnia magna, and Aqueous Residue
Journal of medical entomology, 2011Co-Authors: Hye-mi Park, Junheon Kim, Kyusik Chang, Byungseok Kim, Gilhah Kim, Yu-jung Yang, Sang-chul Shin, Ilkwon ParkAbstract:The larvicidal activity of 11 Myrtaceae essential oils and their constituents was evaluated against Aedes aegypti L. Of the 11, Melaleuca linariifolia Sm., Melaleuca dissitiflora F. Muell., Melaleuca quinquenervia (Cav.) S. T. Blake, and Eucalyptus globulus Labill oils at 0.1 mg/ml exhibited > or = 80% larval mortality. At this same concentration, the individual constituents tested, allyl isothiocyanate, alpha-terpinene, p-cymene, (+)-limonene, (-)-limonene, gamma-terpinene, and (E)-nerolidol, resulted in > or = 95% mortality. We also tested the acute toxicity of these four active oils earlier mentioned and their constituents against Daphnia magna Straus. M. linariifolia and allyl isothiocyanate was the most toxic to D. magna. Twodays after treatment, residues of M. dissitiflora, M. linariifolia, M. quinquenervia, and E. globulus oils in water were 55.4, 46.6, 32.4, and 14.8%, respectively. Less than 10% of allyl isothiocyanate, alpha-terpinene, p-cymene, (-)-limonene, (+)-limonene, and gamma-terpinene was detected in the water at 2 d after treatment. Our results indicated that oils and their constituents could easily volatilize in water within a few days after application, thus minimizing their effect on the aqueous ecosystem. Therefore, Myrtaceae essential oils and their constituents could be developed as control agents against mosquito larvae.
Phillip M Altman - One of the best experts on this subject based on the ideXlab platform.
-
an ex vivo assessor blind randomised parallel group comparative efficacy trial of the ovicidal activity of three pediculicides after a single application Melaleuca oil and lavender oil eucalyptus oil and lemon tea tree oil and a suffocation pediculic
BMC Dermatology, 2011Co-Authors: Phillip M AltmanAbstract:There are two components to the clinical efficacy of pediculicides: (i) efficacy against the crawling-stages (lousicidal efficacy); and (ii) efficacy against the eggs (ovicidal efficacy). Lousicidal efficacy and ovicidal efficacy are confounded in clinical trials. Here we report on a trial that was specially designed to rank the clinical ovicidal efficacy of pediculicides. Eggs were collected, pre-treatment and post-treatment, from subjects with different types of hair, different coloured hair and hair of different length. Subjects with at least 20 live eggs of Pediculus capitis (head lice) were randomised to one of three treatment-groups: a Melaleuca oil (commonly called tea tree oil) and lavender oil pediculicide (TTO/LO); a eucalyptus oil and lemon tea tree oil pediculicide (EO/LTTO); or a "suffocation" pediculicide. Pre-treatment: 10 to 22 live eggs were taken from the head by cutting the single hair with the live egg attached, before the treatment (total of 1,062 eggs). Treatment : The subjects then received a single treatment of one of the three pediculicides, according to the manufacturers' instructions. Post-treatment: 10 to 41 treated live eggs were taken from the head by cutting the single hair with the egg attached (total of 1,183 eggs). Eggs were incubated for 14 days. The proportion of eggs that had hatched after 14 days in the pre-treatment group was compared with the proportion of eggs that hatched in the post-treatment group. The primary outcome measure was % ovicidal efficacy for each of the three pediculicides. 722 subjects were examined for the presence of eggs of head lice. 92 of these subjects were recruited and randomly assigned to: the "suffocation" pediculicide (n = 31); the Melaleuca oil and lavender oil pediculicide (n = 31); and the eucalyptus oil and lemon tea tree oil pediculicide (n = 30 subjects). The group treated with eucalyptus oil and lemon tea tree oil had an ovicidal efficacy of 3.3% (SD 16%) whereas the group treated with Melaleuca oil and lavender oil had an ovicidal efficacy of 44.4% (SD 23%) and the group treated with the "suffocation" pediculicide had an ovicidal efficacy of 68.3% (SD 38%). Ovicidal efficacy varied substantially among treatments, from 3.3% to 68.3%. The "suffocation" pediculicide and the Melaleuca oil and lavender oil pediculicide (TTO/LO) were significantly more ovicidal than eucalyptus oil and lemon tea tree oil pediculicide (EO/LTTO) (P < 0.0001). Ranking: 1. "Suffocation" pediculicide (68.3% efficacy against eggs); 2. Melaleuca oil and lavender oil (44.4%) pediculicide; 3. Eucalyptus oil and lemon tea tree oil (3.3%) pediculicide. The "suffocation" pediculicide and TTO/LO are also highly efficacious against the crawling-stages. Thus, the "suffocation" pediculicide and TTO/LO should be recommended as first line treatments. The study was listed at the Australian/New Zealand Clinical Trial Registry (ANZCTR): reg. no. 12609000884202 .
-
a randomised assessor blind parallel group comparative efficacy trial of three products for the treatment of head lice in children Melaleuca oil and lavender oil pyrethrins and piperonyl butoxide and a suffocation product
BMC Dermatology, 2010Co-Authors: Phillip M AltmanAbstract:Background There are many different types of pediculicides available OTC in Australia. In this study we compare the efficacy and safety of three topical pediculicides: a pediculicide containing Melaleuca oil (tea tree oil) and lavender oil (TTO/LO); a head lice "suffocation" product; and a product containing pyrethrins and piperonyl butoxide (P/PB).
Paul D Pratt - One of the best experts on this subject based on the ideXlab platform.
-
natural enemies affect the seed and litter fall dynamics of Melaleuca quinquenervia in the wetlands and influence long term species diversity in leaf litter
Wetlands Ecology and Management, 2019Co-Authors: Min B Rayamajhi, Philip W Tipping, Paul D Pratt, Jorge Leidi, Leroy RodgersAbstract:The exotic tree Melaleuca quinquenervia (Melaleuca) has invaded and formed monotypic forest stands in ecologically sensitive wetlands of Florida. We hypothesized that natural-enemy impact would influence Melaleuca’s litter and seed fall dynamics via chronic attacks, and enhance native species diversity, which will be reflected in leaf litter composition. This hypothesis was tested during 1997–2013 by studying Melaleuca stands in occasionally inundated habitats infested by its natural enemies. Results from our study showed: (1) an initial increase in the leaf and seed fall during the first-half of the study period, followed by about 70% decline during remainder of the study period, (2) a positive correlation between the amount of leaf and seed fall, (3) a negative correlation between the proportion of natural-enemy damaged Melaleuca leaf litter and the quantity of fallen seeds, and (4) a slow but steady increase of the non-Melaleuca leaf litter amount by 81% and with a corresponding decrease in Melaleuca leaf litter by 15%. Of the 17 non-Melaleuca species recovered, we recorded two perennials at the onset of the study, which increased to seven during the second half of the study period, one of which was non-native. Cladium and Myrsine species produced significantly more leaf-litter by the end of the study period. Over 80% of the Melaleuca leaf litter manifested natural-enemy damage during the last 7-year of the study period. These results provide evidence of a negative influence of natural enemy attack on Melaleuca leaf and seed fall dynamics and a positive influence on native species diversity in the fallen leaf litter.
-
response of two chemotypes of Melaleuca quinquenervia myrtales myrtaceae saplings to colonization by specialist herbivores
Florida Entomologist, 2016Co-Authors: Philip W Tipping, Melissa R Martin, Paul D Pratt, Gregory S Wheeler, Lyn A GettysAbstract:Abstract Two chemotypes of Melaleuca quinquenervia (Cav.) S. T. Blake (Myrtales: Myrtaceae) saplings were planted in a common garden under 2 water treatments and exposed to either restricted or unrestricted herbivory from 2 insect herbivores. Chemotypes consisted of either a predominately E-nerolidol terpenoid complex or one that consisted primarily of viridiflorol; both types had influenced the performance or preference of both insect herbivores in laboratory studies. The densities of the 2 specialist herbivores Boreioglycaspis Melaleucae Moore (Hemiptera: Psyllidae) and Oxyops vitiosa Pascoe (Coleoptera: Curculionidae) were monitored regularly as they colonized the plantings, as were plant responses like leaf abscission and tree height. Neither the chemotype nor the water treatments influenced the densities of B. Melaleucae and O. vitiosa. Trees subjected to unrestricted herbivory shed more leaf biomass than those protected by insecticides from herbivory. There was no relationship between the amount of ...
-
Biological control of Melaleuca quinquenervia: an Everglades invader
BioControl, 2012Co-Authors: Ted D. Center, Philip W Tipping, Paul D Pratt, Min B Rayamajhi, Matthew F Purcell, Susan A. Wright, F. Allen DrayAbstract:A massive effort is underway to restore the Florida Everglades, mainly by re-engineering hydrology to supply more water to the system at appropriate times of the year. However, correcting water flow patterns alone will not restore the associated plant communities due to habitat-transforming effects of invasive species, in particular the Australian wetland tree Melaleuca quinquenervia (Cav.) S. T. Blake (Myrtales, Myrtaceae), which has invaded vast areas and transformed sawgrass marshes into dense, biologically impoverished, structurally altered forest habitats. To address this threat, an invasive species reduction program was launched that combined mechanical removal and herbicidal control to remove mature trees with the release of specialized insects to suppress seed production and lower seedling survival. Melaleuca has now been removed from most public lands while biological control has limited its ability to regenerate and reinvade from nearby infestations often located on unmanaged privately held lands. This case illustrates how restoration of highly modified ecosystems may require both restoration of physical conditions (water flow), and suppression of high impact or transformative invaders, showing well the need to integrate biological control into conservation biology.
-
initial impacts and field validation of host range for boreioglycaspis Melaleucae moore hemiptera psyllidae a biological control agent of the invasive tree Melaleuca quinquenervia cav blake myrtales myrtaceae leptospermoideae
Environmental Entomology, 2007Co-Authors: Paul D Pratt, Philip W Tipping, Min B Rayamajhi, Thai K Van, Susan A Wineriter, Allen F DrayAbstract:Invasion of south Florida wetlands by the Australian paperbark tree, Melaleuca quinquenervia (Cav.) S.T. Blake (Melaleuca), has caused adverse economic and environmental impacts. The tree's biological attributes and favorable ambient biophysical conditions combine to complicate efforts to restore and maintain south Florida ecosystems. Management requires an integrated strategy that deploys multiple biological control agents to forestall reinvasion and to supplement other control methods, thereby lessening recruitment and regeneration after removal of existing trees. This biological control program began during 1997 when an Australian weevil, Oxyops vitiosa (Pascoe), was released. A second Australian insect, the Melaleuca psyllid (Boreioglycaspis Melaleucae Moore), first introduced during 2002, has also widely established. After inoculation of the psyllid in a field study, only 40% of seedlings survived herbivory treatments compared with 95% survival in controls. The resultant defoliation also reduced growth of the surviving seedlings. A weevil-induced decline at a site comprised mainly of coppicing stumps had slowed after a 70% reduction. Psyllids colonized the site, and 37% of the remaining coppices succumbed within 10 mo. The realized ecological host range of B. Melaleucae was restricted to M. quinquenervia; 18 other nontarget plant species predicted to be suboptimal or nonhosts during laboratory host range testing were unaffected when interspersed with psyllid-infested Melaleuca trees in a common garden study. Evaluations are ongoing, but B. Melaleucae is clearly reducing seedling recruitment and stump regrowth without adversely impacting other plant species. Manifestation of impacts on mature trees will require more time, but initial indications suggest that the psyllid will be an effective supplement to the weevil.
-
field colonization population growth and dispersal of boreioglycaspis Melaleucae moore a biological control agent of the invasive tree Melaleuca quinquenervia cav blake
Biological Control, 2006Co-Authors: Paul D Pratt, Philip W Tipping, Min B Rayamajhi, Thai K Van, Susan A Wineriter, Allen F Dray, Matthew F PurcellAbstract:Abstract Invasion of native plant communities by the Australian paperbark tree (“Melaleuca”), Melaleuca quinquenervia, complicates restoration of the Florida Everglades. Biological control, within the context of a comprehensive management program, offers a means to suppress regeneration of Melaleuca after removal of existing trees and a mechanism to forestall reinvasion. To meet this need, a biological control program commenced in 1997 upon the release of an Australian weevil (Oxyops vitiosa [Pascoe] [Coleoptera: Curculionidae]). Release of a second biological control agent, the Melaleuca psyllid (Boreioglycaspis Melaleucae Moore), followed in February 2002 at field sites containing mixed age-class Melaleuca stands or coppicing stumps. Each site was inoculated with 7000–10,000 adult psyllids, with one exception where 2000 nymphs were released on seedlings the following December. Psyllid populations established everywhere irrespective of colony source, site conditions, or the quantity released, although numbers released and, to a lesser degree, colony age influenced the numbers of colonies produced. Quantity included in the release was the major determinant of the resultant number of colonies, although the duration of their tenure in quarantine culture may have also influenced this. One site, comprised mainly of coppicing stumps, contained 3.3 million psyllids per ha within 3 months after release. Less than 1% of the coppices at a similar site harbored psyllid colonies 2 months after release (May 2002), but this rose to 75% in October then to 100% by December. The census population exceeded 715,000 adults and nearly 11 million nymphs by late January 2003. Psyllid populations dispersed 2.2–10.0 km/year, with the slower rates in dense, continuous Melaleuca stands and faster rates in fragmented stands. Over 1 million psyllids had been redistributed to 100 locations as of December 2005. This species now occurs throughout much of the range of Melaleuca in south Florida due to natural range expansion as well as anthropogenic dissemination.