Article

Pharmacological and antimicrobial studies on different tea-tree oils (Melaleuca alternifolia, Leptospermum scoparium or Manuka and Kunzea ericoides or Kanuka), originating in Australia and New Zealand

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Abstract

Three different species of Myrtaceae growing in Australia and New Zealand are known as 'Tea-tree': the Australian Tea tree (Melaleuca alternifolia), the New Zealand Manuka (Leptospermum scoparium) and Kanuka (Kunzea ericoides). All three essential oils are used by aromatherapists, although only Melaleuca has been tested for toxicity, and its antimicrobial effects studied. The pharmacology and antimicrobial activity of the three 'tea-tree' oils was determined using guinea-pig ileum, skeletal muscle (chick biventer muscle and the rat phrenic nerve diaphragm) and also rat uterus in vitro. Differences were shown between the three essential oils in their action on smooth muscle: Manuka had a spasmolytic action, while Kanuka and Melaleuca had an initial spasmogenic action. Using the diaphragm, Manuka and Melaleuca decreased the tension and caused a delayed contracture; Kanuka had no activity at the same concentration. The action on chick biventer muscle was, however, similar for all three oils, as was the action on the uterus, where they caused a decrease in the force of the spontaneous contractions. The latter action suggests caution in the use of these essential oils during childbirth, as cessation of contractions could put the baby, and mother, at risk. The comparative antimicrobial activity showed greater differences between different samples of Manuka and Kanuka than Melaleuca samples. The antifungal activity of Kanuka was inversely proportional to its strong antibacterial activity, whilst Manuka displayed a stronger antifungal effect, though not as potent as Melaleuca. The antioxidant activity of Manuka samples was more consistent than that of Kanuka, while Melaleuca showed no activity. The variability in the Manuka and Kanuka essential oils suggests caution in their usage, as does the fact that the oils have not been tested for toxicity.

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... The capsules or leaves could also be chewed to relieve dysentery. 4 A decoction formed by boiling the leaves and bark has proven effective for treating breast inflammation, back stiffness, and eye problems. A poultice formed from pounded capsules of the plants was used to dry open wounds or running sores and to treat scald and burn injuries. ...
... Internal and external use of these oils by herbalists and aroma therapists has as well increased in the past twenty years. 4,11 The recent emergence of new strains of bacteria and fungi warrants intensive study of therapeutic agents for their control and eradication. 29,30 Due to the widespread use of tea tree oils for body massage and aromatherapy, in vivo studies have been performed to investigate their pharmacological and antimicrobial activities in guinea pig ileum, rat uterus, rat skeletal muscle, chick biventer muscle, and rat phrenic nerve diaphragm. ...
... 29,30 Due to the widespread use of tea tree oils for body massage and aromatherapy, in vivo studies have been performed to investigate their pharmacological and antimicrobial activities in guinea pig ileum, rat uterus, rat skeletal muscle, chick biventer muscle, and rat phrenic nerve diaphragm. 4 Studies of manuka honey produced by New Zealand tea trees suggested that, whereas the antibacterial properties of honey products are derived from hydrogen peroxide, those of manuka oil are derived through other mechanisms. 31,32 Our data indicate that both oils might possess various properties to inhibit microorganism growth. ...
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Background Diseases caused by infectious and inflammatory microorganisms are among the most common and most severe nosocomial diseases worldwide. Therefore, developing effective agents for treating these illnesses is critical. In this study, essential oils from two tea tree species, kanuka (Kunzea ericoides) and manuka (Leptospermum scoparium), were evaluated for use in treating diseases and inflammation caused by microorganism infection. Methods Isolates of clinically common bacteria and fungi were obtained from American Type Culture Collection and from Kaohsiung Veterans General Hospital. Minimum inhibitory concentrations for Trichosporon mucoides, Malassezia furfur, Candida albicans, and Candida tropicalis were determined by the broth microdilution method with Sabouraud dextrose broth. The antibacterial susceptibility of Staphylococcus aureus, Streptococcus sobrinus, Streptococcus mutans, and Escherichia coli were determined by the broth microdilution method. A human acute monocytic leukemia cell line (THP-1) was cultured to test the effects of the essential oils on the release of the two inflammatory cytokines, tumor necrosis factor-α and interleukin-4. Results Multiple analyses of microorganism growth confirmed that both essential oils significantly inhibited four fungi and the four bacteria. The potent fungicidal properties of the oils were confirmed by minimum inhibitory concentrations ranging from 0.78% to 3.13%. The oils also showed excellent bactericidal qualities with 100% inhibition of the examined bacteria. In THP-1 cells, both oils lowered tumor necrosis factor-α released after lipopolysaccharide stimulation. Finally, the antimicrobial and anti-inflammatory effects of the oils were obtained without adversely affecting the immune system. Conclusion These results indicate that the potent antimicroorganism and anti-inflammation properties of kanuka and manuka essential oils make them strong candidates for use in treating infections and immune-related disease. The data confirm the potential use of kanuka and manuka extracts as pharmaceutical antibiotics, medical cosmetology agents, and food supplements.
... Some of these aromatic species have been used historically by the Australian aborigines as well as by the early European settlers for a variety of infectious-related conditions including urinary tract conditions, intestinal complaints, coughs, colds, skin conditions, burns, scalds, mouth washes, gargles and gum disease (Maddocks-Jennings et al., 2005;Carson et al., 2006). The most popular, commercialised and well-studied tea tree species is undoubtedly M. alternifolia (Carson et al., , 1996(Carson et al., , 2002(Carson et al., , 2006Mann et al., 2000;Hart et al., 2000;Homer et al., 2000;Lis-Balchin et al., 2000;Banes-Marshall et al., 2001;Cox et al., 2001;Christoph et al., 2001;Russel and Southwell, 2003;Hammer et al., 2004). In comparison, research on other tea tree species such as L. petersonii, L. scoparium and K. ericoides have been somewhat neglected. ...
... The essential oil composition of this species has been reported (Douglas et al., 2004), however, monthly variation studies have not been undertaken. Antimicrobial efficacies against selected pathogens such as Candida albicans, Staphylococcus spp., Escherichia coli and Pseudomonas aeruginosa have been investigated (Williams et al., 1998;Porter and Wilkins, 1999;Lis-Balchin et al., 2000). In a detailed review of this species (Stephens et al., 2005), the antimicrobial efficacies were not discussed, possibly due to the lack of anti-infective data known for this species. ...
... Although some chemical data has been published (Penfold et al., 1948;Porter and Wilkins, 1999), no detailed seasonal variation studies have been conducted on this species. Although the antimicrobial activity by disc diffusion has been reported by Lis-Balchin et al. (2000), limited attention has been given to the quantitative antimicrobial evaluation of K. ericoides. ...
Article
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The essential oil composition of three Myrtaceous species (Leptospermum petersonii, Leptospermum scoparium and Kunzea ericoides) belonging to the tea tree group were analysed using gas chromatography coupled to mass spectrometry (GC–MS). The major compounds determined from the mean ± SD of the monthly samples collected for one calendar year in L. petersonii are citronellal (11.4 ± 4.3%), citronellol (17.5 ± 7.1%), neral (19.7 ± 1.6%) and geranial (34.7 ± 3.3%). The major compounds in L. scoparium are eudesma-4(14)-11-diene (11.6 ± 2.4%), α-selinene (10.4 ± 2.3%) and (E)-methyl cinnamate (12.6 ± 3.8%). The major compounds in K. ericoides are α-pinene (37.6 ± 6.3%) and p-cymene (13.5 ± 4.1%). The essential oils show some promising antimicrobial activity against selected micro-organisms when investigated using the minimum inhibitory concentration assay. Highest sensitivities were noted for the Brevibacteria (lowest MIC value of 0.06 mg/ml), a genus associated with foot odour. When the different essential oils were combined in various ratios and tested against Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans, a predominantly additive effect was noted.
... pylori) found mānuka oil to be the seventh most effective antibacterial when diluted in propylene glycol (500 μg/mL after 1 h and 40 μg/mL after 24 h) [46]. Mānuka oil derived from the North Island of New Zealand displayed significant antibacterial activity against 20/20 Listeria monocytogenes strains, whereas more so than that of mānuka oil from the South Island was effective against (0/20 Listeria monocytogenes strains) [28]. Higher levels of β-triketones found in chemotypes growing in the North Island of New Zealand, are likely to be contributory to these differences [11]. ...
... The effect of mānuka oil on Aspergillus niger, A. ochraceous and F. culmorum was assessed in another study, which found wide variation in the antifungal activity depending on the source of mānuka oil; the mānuka oil sample from the South Island of New Zealand had greater antifungal activity against A. ochraceus and F. culmorum than mānuka oil from the North Island [28]. The fungicidal activity of mānuka oil was assessed for a series of human fungal species, Malassezia furfur, Trichosporon mucoides, Candida albicans and C. tropicalis, with a MIC of 1.56% for M. furfur and T. mucoides and 3.13% for both Candida species [37]. ...
... The diluent used in the study by Chen et al. was not specified and this discrepancy could be a result of diluting the lipophilic mānuka oil in aqueous cell culture media. Lis-Balchin et al. (2000) also showed the antioxidant effects of mānuka oil from the North-and Southislands of New Zealand were more consistent in comparison to kanuka oil [28]. ...
Article
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Mānuka oil is an essential oil derived from Leptospermum scoparium, a plant that has been used by the indigenous populations of New Zealand and Australia for centuries. Both the extracted oil and its individual components have been associated with various medicinal properties. Given the rise in resistance to conventional antibiotics, natural products have been targeted for the development of antimicrobials with novel mechanism of action. This review aimed to collate available evidence on the antimicrobial, anti-parasitic and anti-inflammatory activities of mānuka oil and its components. A comprehensive literature search of was conducted using PubMed and Embase (via Scopus) targeting articles from database inception until June 2020. Chemical structures and IUPAC names were sourced from PubChem. Unpublished information from grey literature databases, Google search, targeted websites and Google Patents were also included. The present review found extensive in vitro data supporting the antimicrobial effects of mānuka oil warrants further clinical studies to establish its therapeutic potential. Clinical evidence on its efficacy, safety and dosing guidelines are necessary for its implementation for medical purposes. Further work on regulation, standardization and characterization of the medicinal properties of mānuka oil is required for establishing consistent efficacy of the product.
... Surprisingly, the positive effect of hydrolyzed DNA-RNA was not synergistic in combination with other tested bioactive molecules, such as hyaluronic acid, β-Glucan, allantoin, bisabolol, ruscogenin, and several essential oils ( Table 2). The aforementioned molecules were proven to have anti-inflammatory, antioxidant, and anti-aging activity, helping in wound healing, epithelial regeneration, and extracellular matrix regeneration [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34]. However, a formulation containing these bioactive molecules in addition to hydrolyzed DNA and RNA did not yield a higher protective effect than the formulation containing DNA and RNA alone. ...
... Antibacterial and antifungal activity [32][33][34]. ...
Article
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Background: DNA-RNA compounds have shown promising protection against cell oxidative stress. This study aimed to assess the cytotoxicity, protective, or preventive effect of different experimental formulations on oral epithelia's oxidative stress in vitro. Methods: Reconstituted human oral epithelia (RHOE) were grown air-lifted in a continuous-flow bioreactor. Mouthwashes and gels containing DNA-RNA compounds and other bioactive molecules were tested on a model of oxidative stress generated by hydrogen peroxide treatment. Epithelia viability was evaluated using a biochemical MTT-based assay and confocal microscopy; structural and ultrastructural morphology was evaluated by light microscopy and TEM. Results: DNA-RNA showed non-cytotoxic activity and effectively protected against oxidative stress, but did not help in its prevention. Gel formulations did not express adequate activity compared to the mouthwashes. Excipients played a fundamental role in enhancing or even decreasing the bioactive molecules' effect. Conclusion: A mouthwash formulation with hydrolyzed DNA-RNA effectively protected against oxidative stress without additional enhancement by other bioactive molecules. Active compounds, such as hyaluronic acid, β-Glucan, allantoin, bisabolol, ruscogenin, and essential oils, showed a protective effect against oxidative stress, which was not synergistic with the one of DNA-RNA. Incorporation of surfactant agents showed a reduced, yet significant, cytotoxic effect.
... Surprisingly, the positive effect of hydrolyzed DNA-RNA was not synergistic in combination with other tested bioactive molecules such as hyaluronic acid, β-Glucan, allantoin, bisabolol, ruscogenin, and several essential oils ( Table 2). The aforementioned molecules were proven to have anti-inflammatory, antioxidant, and anti-aging activity, helping in wound healing, epithelial regeneration, and extracellular matrix regeneration [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34]. However, a formulation containing these bioactive molecules in addition to hydrolyzed DNA and RNA did not yield a higher protective effect than the formulation containing hydrolyzed alone. ...
... Antibacterial and antifungal activity [32][33][34]. ...
Preprint
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Background: DNA-RNA compounds have shown promising protection against cell oxidative stress. This study aimed to assess the cytotoxicity, protective, or preventive effect of different experimental formulations on oral epithelia’s oxidative stress in vitro. Methods: Reconstituted human oral epithelia (RHOE) were grown air-lifted in a continuous-flow bioreactor. Mouthwash and gels containing DNA-RNA compounds and other bioactive molecules were tested on a model of oxidative stress generated by hydrogen peroxide treatment. Epithelia viability was evaluated using a biochemical MTT-based assay and confocal microscopy; structural and ultrastructural morphology was evaluated by light microscopy and TEM. Results: DNA-RNA showed non-cytotoxic activity and effectively protected against oxidative stress, but not in its prevention. Gel formulation did not express adequate activity compared to the mouthwash. Excipients played a fundamental role in enhancing or even decreasing the bioactive molecules’ effect. Conclusion: A mouthwash formulation with hydrolyzed DNA-RNA effectively protected against oxidative stress without additional enhancement by other bioactive molecules. Active compounds such as hyaluronic acid, β-Glucan, allantoin, bisabolol, ruscogenin, and essential oils showed a protective effect against oxidative stress, which was not synergistic with the one of DNA-RNA. Surfactant agents showed harmful activity against oral epithelia.
... The essential oil and unique honey produced by this plant has drawn considerable attention for commercial purposes due to their potent antimicrobial properties. The mānuka essential oil has antioxidant effects and inhibits the growth of Bacillus subtilis, a food spoilage organism and Trichophyton mentayrophus, an opportunistic human pathogen that infects skin, nails and hair and causes dermatophytosis [5,6]. Medicinal plants recognised for antimicrobial metabolites may also be a source of endophytes with biocontrol activity or that produce new antimicrobial compounds [7][8][9]. ...
... This is the first study to characterise the structure of mānuka endomicrobiome and to demonstrate the bioactivity of culturable bacteria from that community. Mānuka (Leptospermum scoparium) is a medicinal plant for which the antimicrobial effects of the unique high triketone oil and honey are well recognized [5,[30][31][32]. ...
Article
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Leptospermum scoparium or m?nuka is a New Zealand native medicinal plant that produces an essential oil with antimicrobial properties. This is the first study to investigate the structure and bioactivity of endophytic bacteria in m?nuka by using a combination of cultivation-independent (DGGE) and dependent approaches. A total of 23 plants were sampled across three sites. Plants were considered either immature (3-8 years) or mature (>20 years). The endophyte community structure and richness was affected by plant tissue and bacterial communities became more stable and uniform as plant maturity increased. A total of 192 culturable bacteria were recovered from leaves, stems and roots. Some bacterial isolates showed in vitro biocontrol activity against two fungal pathogens, Ilyonectria liriodendri and Neofusicoccum luteum and a bacterial pathogen, Pseudomonas syringae pv. actinidiae. A high proportion of bacterial endophytes could produce siderophores and solubilise phosphate in vitro. Gammaproteobacteria was the most variable class, representing the majority of cultivated bacteria with bioactivity.
... Another plant secondary metabolite − terpinen-4-ol − a monoterpenoid alcohol found in the essential oil of many reputed medicinal plants, e.g. Alpinia speciose (shellflower), Melaleuca alternifolia (narrow-leaved paperbark), Camellia sinensis (tea plant), Myrtus communis (common myrtle), Laurus nobilis (bay laurel), Croton sonderianus ("quebra-faca") or Eucalyptus globulus (Tasmanian blue gum) de- creased the spontaneous and pharmacologically-induced contractility of rabbit duodenum (Lis- Balchin et al., 2000;Nascimento et al., 2005). Melaleuca alternifolia, another example of a plant able to inhibit methane production ( Durmic et al., 2014), showed initially a spasmogenic action which was then followed by a spasmolytic action towards guinea-pig ileum smooth muscle (Lis- Balchin et al., 2000). ...
... Alpinia speciose (shellflower), Melaleuca alternifolia (narrow-leaved paperbark), Camellia sinensis (tea plant), Myrtus communis (common myrtle), Laurus nobilis (bay laurel), Croton sonderianus ("quebra-faca") or Eucalyptus globulus (Tasmanian blue gum) de- creased the spontaneous and pharmacologically-induced contractility of rabbit duodenum (Lis- Balchin et al., 2000;Nascimento et al., 2005). Melaleuca alternifolia, another example of a plant able to inhibit methane production ( Durmic et al., 2014), showed initially a spasmogenic action which was then followed by a spasmolytic action towards guinea-pig ileum smooth muscle (Lis- Balchin et al., 2000). Analogically, thymol, the major active ingredient of Thymus vulgaris essential oil, induced a dual, spasmogenic followed by spasmolytic, effect on guinea pig isolated stomach smooth muscle (Beer et al., 2007). ...
Article
The increasing requirement for implementing new feed additives in livestock, especially ruminants, results predominantly from two issues: the urgent need of reduction of greenhouse gas emissions and the necessity of finding replacements of antibiotics which must not be preventively used in animals feeding. A group of additives that has gained a progressive interest in recent years consists of plant secondary metabolites and plant-derived extracts. There is extensive knowledge of the effects of phytogenic feed additives on rumen microbial fermentation, rumen methanogenesis and ruminant performance. However, there is little information about their systemic effects. In case of ruminants, the possible impact of employed additives on gut motility should be carefully analyzed due to the special anatomical and physiological features. Therefore, the aim of this review is to present available data on the effects of plant extracts and individual secondary plant metabolites which can be potentially used as feed additives on gastrointestinal motility. The review describes the impact of essential oils, tannins and saponins on gut smooth muscle activity in laboratory animals and livestock, particularly ruminants, under in vivo and in vitro conditions The analysis of gathered data allows to generalize that most essential oils, tannins and saponins which are under consideration as phytogenic feed additives generate myorelaxant effects towards gastrointestinal tissues. Significant antispasmodic effects of plant secondary metabolites can reduce the gastrointestinal smooth muscle basal tone and cause an impaired response of rumen and abomasal muscles to acetylcholine which reflect hypotony and subsequently predispose the animals to some gut disturbances, like abomasal displacement or rotation, and or indigestion. On the other hand, the revealed ability of various plant extracts to reduce acetylcholine-induced contraction could be used to contract gastrointestinal muscle spasm and consequently become beneficial in animals with diarrhea symptoms. Noteworthy, essential oils of numerous plants turned out to act spasmogenic if used in low doses and spasmolytic whenever tested in higher concentrations. This dual character of essential oils should be further analyzed and possible used to treat or prevent hypo- and hypermotility disorders. Bearing in mind, the process of gut microorganisms’ adaptation and their ability to decompose or neutralize various substances, including plant secondary metabolites, the effects of plant-derives substances on gastrointestinal motoric activity are especially expected in a short time after the introduction of a new phytocompound or plant extract to animal feed.
... Manuka (Myrtaceae: Leptospermum scoparium J.R. Forst and G. Forst) also known as "tea tree", is one of the most abundant and widespread indigenous shrub species in New Zealand. Early records report the traditional use of the bark, leaves, sap, and seed capsules from manuka for treatment of various diseases and ailments including fever, cough, mouth and throat sores, running nose, dysentery, diarrhea, colic pain, breast inflammation, back stiffness, eye problems, and scald and burn injuries [9,10]. Essential oil derived from L. scoparium is also used as a strong antimicrobial and antifungal agent in creams, soaps, toothpastes and other preparations [11,12]. ...
... Essential oil derived from L. scoparium is also used as a strong antimicrobial and antifungal agent in creams, soaps, toothpastes and other preparations [11,12]. During World War II, L. scoparium essential oil was provided in the first aid kits of serving Australian soldiers for use as a general antimicrobial agent and insect repellent [10]. Other studies have demonstrated the toxicity of L. scoparium essential oil and some of its fractions against arthropods of economic and medical significance including the spotted wing drosophila Drosophila suzukii Matsumura, itch mite, Sarcoptes scabiei Linnaeus, poultry red mite, Dermanyssus gallinae De Geer, stored food mite, Tyrophagus putrescentiae Schrank, and house dust mites, Dermatophagoides farinae Hughes and D. pteronyssinus Troussart [13][14][15][16]. ...
Article
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Synthetic pesticides are the cornerstone of vector-borne disease control, but alternatives are urgently needed to tackle the growing problem of insecticide resistance and concerns over environmental safety. Leptospermum scoparium J.R. Forst and G. Forst (manuka) essential oil and its four fractions were analyzed for chemical composition and toxicity against Aedes aegypti larvae. The use of bio-based amylose-N-1-hexadecylammonium chloride inclusion complexes (Hex-Am) as an emulsifier for L. scoparium essential oil was also investigated. Fraction 1 was inactive, fractions 2 (LC50 = 12.24 ppm) and 3 (LC50 = 20.58 ppm) were more toxic than the whole essential oil (LC50 = 47.97 ppm), and fraction 4 (LC50 = 35.87 ppm) had similar toxicity as the whole essential oil. Twenty-one chemical constituents were detected in L. scoparium essential oil compared to 16, 5, 19 and 25 chemical constituents in fractions, 1, 2, 3 and 4 respectively. The two most dominant chemical constituents were calamenene (17.78%) and leptospermone (11.86%) for L. scoparium essential oil, calamenene (37.73%) and ledene (10.37%) for fraction 1, leptospermone (56.6%) and isoleptospermone (19.73) for fraction 2, cubenol (24.30%) and caryophyllene oxide (12.38%) for fraction 3, and γ-gurjunene (21.62%) and isoleptospermone (7.88%) for fraction 4. Alpha-pinene, ledene, and aromandendrene were 2–7 times less toxic than the whole essential suggesting that the toxicity of L. scoparium essential oil was either due to other chemical constituents that were not tested or due synergist interactions among chemical constituents. Leptospermum scoparium essential oil-Hex-Am emulsion (LC50 = 29.62) was more toxic than the whole essential oil. These findings suggest that L. scoparium essential oil is a promising source of mosquito larvicide and that Hex-Am is an excellent emulsifier for L. scoparium essential oil for use as a larvicide.
... These compounds have antifungal, antibacterial, and antiinflammatory activity. 67,68 In a randomized placebocontrolled trial study, 19 adult patients used a gargle containing 2 drops of a 1:1 mix of the essential oils of manuka. Overall, the active gargle was well tolerated by patients with no evidence of toxic or side effects relating to its swallowing. ...
... 73 Clinical outcome: Avoid using it during pregnancy because of spasmolytic activity. 68 ...
Article
Oral mucositis is a common side effect of systemic chemotherapy and radiotherapy of head and neck in patients with cancer. Severe oral mucositis is painful and affects oral functions, including intake of food and medications and speech. Prevention of oral mucositis affects the life quality of patients. Recent studies have been focused on natural products to improve or reduce this complication. Many clinical trials have been performed to assess natural products for treatment of mucositis and their results are promising. The authors reviewed the evidence for natural products in the prevention and treatment of oral mucositis induced by radiation therapy and chemotherapy. © The Author(s) 2015.
... Manuka (Leptospermum scoparium) is a shrub of the Myrtaceae family, original of Australia and New Zealand, but cultivated worldwide, mainly for honey production. Several studies have investigated the antimicrobial properties of manuka essential oil (EO), showing its effectiveness on L. monocytogenes and, more often, on S. aureus (Harkenthal et al., 1999;Lis-Balchin, 2000;Van Klink et al., 2005;Fratini et al., 2019). ...
Article
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The activity of manuka (Leptospermum scoparium) essential oil (EO) on biofilms of foodborne Listeria monocytogenes and Staphylococcus aureus has been studied. Seven strains of L. monocytogenes and 7 of S. aureus (5 methicillin-resistant) were tested. EO minimal inhibitory concentration (MIC), EO minimal bactericidal concentration (MBC) and biofilm production quantification were determined for each strain by microtiter methods. Moreover, EO Minimum Biofilm Inhibitory Concentration (MBIC) and Minimum Biofilm Eradicating Concentration (MBEC) were determined on 2 L. monocytogenes and 3 S. aureus that showed the best biofilm production. Finally, on 4 strains out of 5 (2 L. monocytogenes and 2 S. aureus) EO Biofilm Reduction Percentage (BRP) vs. untreated controls was assessed after a treatment with EO subinhibitory concentrations. The chemical composition of manuka essential oil was determined by Gas Chromatography- Electron Impact Mass Spectrometry (GCEIMS). The manuka EO demonstrated good antimicrobial activity: L. monocytogenes MIC and MBC were 0.466 mg/ml and 0.933 mg/ml, respectively, whereas S. aureus MIC and MBC were 0.233 mg/ml and 0.466 mg/ml, respectively. Furthermore, L. monocytogenes showed a MBIC of 0.933 mg/ml and a MBEC in the range of 0.933–1.865 mg/ml, whereas S. aureus had a MBIC in the range of 7.461–14.922 mg/ml and a MBEC of 14.922 mg/ml. L. monocytogenes revealed no significant BRP after the treatment with manuka EO, whereas S. aureus showed a BRP higher than 50% with MIC/2 and MIC/4 EO concentrations. These results provide information for feasible manuka EO applications in food production systems.
... This matches findings of other researchers: aqueous extracts of kinos from 13 Eucalyptus species had activity against the gram-positive bacteria S. aureus and B. subtilis, 13 whilst aqueous extracts of E. olida and E. staigerana also showed activity against S. aureus (MIC 15.6 μg/ml and 125 μg/ml, respectively) although no activity against six other bacteria. 3 The essential oils of M. alternifolia have well documented antibacterial activity against a broad spectrum of bacteria 15,19,24,25 Pharmacognosy Communications, Vol 6, Issue 2, Apr-Jun, 2016 Table 1: Absorbance of bacterial cultures was measured at 600 nm. The level of extract activity was compared to positive (no extract) control: "+++" <10% control absorbance (very inhibitory); "++" 10-49% control absorbance (inhibitory); "+/-" 50-99% control absorbance (neutral); "-" ³100% control absorbance (enhanced growth) Prostanthera species, like many other Australian plants, have been shown to have essential oils with potent antimicrobial activity. ...
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Introduction: Significant effort has been invested in looking at the antimicrobial activity of plant extracts from tropical regions of Australia, with less interest in those from more temperate environments. We sought to redress this imbalance by examining antimicrobial activities of extracts from native plants of Victoria. Methods: Sixteen plant samples were obtained around the Ballarat region of Victoria. Plant material was desiccated, ground and extracted with methanol at room temperature. Methanol extracts were subsequently dissolved in water, filtered and freeze dried. Extracts were dissolved in water and their activity determined against eight bacterial species. Plant extracts that showed appreciable antibacterial activity in the initial antimicrobial screen were examined further with both their MICs and MBCs determined. Results: Ten of the sixteen plant extracts showed antimicrobial activity. Extracts of Eucalyptus, Melaleuca, Prostanthera and Westringia were particularly active with MICs as low as 0.25 mg/ml against organisms including P. aeruginosa and S. aureus. Conclusion: The current study demonstrates the antimicrobial activity of plant extracts from temperate Australia. These may serve as precursors for future chemotherapy agents.
... [3,[8][9][10][11] Its antiviral and antifungal potencies against Trichomonas gallinae, Trypanosoma cruzi and Leishmania amazonensis have been documented by Costa et al., [12] Ibikunle et al., [13] Santos et al. [14] and Rodrigue et al. [15] Thus, Pitanga oil has become an important ingredient in cosmetic, pharmaceutical, food and beverage products. [16][17][18] The choice of extraction methods, such as mechanical pressing, pressurized solvent extraction, Soxhlet extraction, ultra-extraction, aqueous enzymatic oil extraction, microwaves-assisted extraction and CO 2 supercritical, employed to obtain essential and bioactive compounds from most seeds, is influenced by targeted quantity, quality and economic purpose. [4,19,20] Interests in the extraction of essential and bioactive compounds in tree-plants includes other parts, such as roots, stem and leaves, besides the seeds and nuts . ...
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Simplex Centroid Design (SCD) was employed to optimise the mixing of petroleum ether, n-hexane, methanol and ethanol for the extraction of oil (PLO) from Pitanga (Eugenia Uniflora L) leaves, via Soxhlet extraction. Highest yield (54%) of PLO was obtained with 100% ethanol and lowest yield (16%) from the mixture of methanol (33.3 %)/hexane (33.3 %)/ethanol (33.3 %). The coefficient of determination (R²) of the model equation obtained was 0.91 while the Adjusted R² and predicted R² were 0.8729 and 0.951. The saponification value, iodine value, acid value and free fatty acid are 35.34mgKOH/g, 72.97mgI2/g oil, 32.41mgKOH/g and 16.30mgKOH/g, respectively.
... Vrednosti MFC za Aspergillus u većini slučajeva nije bilo moguće odrediti jer su prevazilazile najveću ispitivanu koncentraciju (>50 μL/ mL). Slične rezultate su pokazali Čen (Chen) i saradnici, kao i Liz-Balkin (Lis-Balchin) i saradnici (15,32). ...
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Introduction: Otomycosis is a superficial fungal infection of the external ear canal. One of the therapeutic approaches that became topical in treatment of otomycosis is the application of essential oils, which is shown to have different biological properties, including the antimicrobial effect. Aim: The objective of the research is to examine antimycotic effects of essential oils of lemon balm (Melissa officinalis), manuka (Leptospermum scoparium) and tansy (Tanacetum vulgare) on the causative agents of otomycosis. Materials and Methods: In this study, we investigated the sensitivity of 20 randomly selected strains of Candida spp. and Aspergillus spp. isolated from swabs taken from the external ear canal of patients with signs and symptoms of otitis externa. Antifungal activity of essential oils of lemon balm, manuka and tansy was tested by using the microdilution method by determining the value of the Minimum inhibitory concentration (MIC) and Minimum fungicidal concentration (MFC). Results: MIC values of lemon balm were in the range of 0.39- 50 μl/ml, manuka of 0.39-50 μL/mL and tansy of 1.56-50 μL/mL. The MFC values were 2-4 times higher than the MIC values, except in the case of a strain of Aspergillus niger, which was tolerant of the lemon balm essential oil. Conclusion: The investigation has shown that essential oil activities of lemon balm, manuka and tansy to the strains of Candida spp. and Aspergillus spp, using the microdilution method, have antifungal effect.
... Generally, cytotoxic activity of EOs and components on human cell lines have been studied with a larger proportion of these studies focusing on the effects of tea tree oil (Söderberg et al. 1996;Lis-Balchin et al. 2000;Hammer et al. 2006;Loughlin et al. 2008;Nielsen 2008). Kpoviessi et al. (2014) investigated the cytotoxic activity of lemongrass EO from four Cymbopogon species; C.citratus, C. giganteus, C. nardus and C. schoenantus against a human non-cancer diploid fibroblast cell line (W138) showing moderate toxicity of C. citratus against this W138 cell line. ...
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The aim of this study was to determine the antimicrobial effects of lemongrass essential oil (C. flexuosus) and to determine cytotoxic effects of both test compounds on human dermal fibroblasts. Antimicrobial susceptibility screening was carried out using the disk diffusion method. Antimicrobial resistance was observed in four of five Acinetobacter baumannii strains with two strains confirmed as multi-drug-resistant (MDR). All the strains tested were susceptible to both lemongrass and citral with zones of inhibition varying between 17 to 80 mm. The mean minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of citral (mic—0.14 % and mbc—0.3 % v/v) was lower than that of Lemongrass (mic—0.65 % and mbc—1.1 % v/v) determined using the microtitre plate method. Cell viability using human dermal fibroblasts (HDF; 106-05a) was determined following exposure to both compounds and a control (Grapeseed oil) using the XTT assay and the IC50 determined at 0.095 % (v/v) for citral and 0.126 % (v/v) for lemongrass. Grapeseed oil had no effect on cell viability. Live cell imaging was performed using the LumaScope 500 imaging equipment and changes in HDF cell morphology such as necrotic features and shrinkage were observed. The ability of lemongrass essential oil (EO) and citral to inhibit and kill MDR A. baumannii highlights its potential for use in the management of drug-resistant infections; however, in vitro cytotoxicity does suggest further tests are needed before in vivo or ex vivo human exposure.
... From a phytochemical point of view, it has been ascertained that several Myrtaceae accumulate flavonoids, tannins, and other phenolic derivatives with ethnobotanical significance (Kuskoski et al. 2003;Fischer et al. 2008). More generally, this family represents an important source of EOs with different biological activities, including antibacterial and antifungal properties (Lis-Balchin et al. 2000;Stefanello et al. 2011). ...
Article
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Mosquitoes transmit serious pathogens and parasites to humans and animals, including malaria, dengue, Japanese encephalitis and filariasis. The extensive use of chemical pesticides leads to the development of resistance in mosquito vector populations and serious non-target effects on human health and the environment. Myrtaceae plants can be a useful reservoir of natural products effective against Culicidae young instars. In this research, we evaluated the mosquitocidal potential of the essential oil (EO) from Syzygium zeylanicum leaves against larvae of three mosquitoes of medical and veterinary importance, the malaria vector Anopheles subpictus, the dengue vector Aedes albopictus, and the Japanese encephalitis vector Culex tritaeniorhynchus. The chemical composition of the EO was analyzed by gas chromatography-mass spectroscopy. GC-MS revealed that the S. zeylanicum EO contained at least 18 compounds. The major chemical components were α-humulene (37.8.5 %) and β-elemene (10.7 %). The EO had a significant toxic effect against early third-stage larvae of An. subpictus, Ae. albopictus, and Cx. tritaeniorhynchus, with LC50 values of 83.11, 90.45, and 97.96 μg/ml, respectively. The two major constituents extracted from the S. zeylanicum EO were tested individually for acute toxicity against larvae of the three mosquito vectors. α-Humulene and β-elemene appeared highly effective against An. subpictus (LC50 = 6.19 and 10.26 μg/ml, respectively), followed by Ae. albopictus (LC50 = 6.86 and 11.15 μg/ml) and Cx. tritaeniorhynchus (LC50 = 7.39 and 12.05 μg/ml). Furthermore, the EO and its major components was safe towards the non-target fish Gambusia affinis; LC50 values were 20374.26, 1024.95, and 2073.18 μg/ml, respectively for EO, α-humulene and β-elemene. Overall, this study highlighted that the acute toxicity of S. zeylanicum EO towards mosquito larvae was mainly due to the presence of α-humulene and β-elemene. Furthermore, we pointed out the concrete possibility to exploit these two compounds from S. zeylanicum EO as highly effective larvicides against young instars of An. subpictus, Ae. albopictus, and Cx. tritaeniorhynchus, with little effect on non-target organisms.
...  Manuka oil has a consistently high antioxidant activity and a marked antifungal effect (Balchin, 2000). ...
Conference Paper
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Disk diffusion assay results and MICs,MBCs determinants showed a marked inhibitory activity of Leptospermum scoparium) essential oil against Gram-positive bacteria, including MRSA, M. phlei and B. Subtilis, and showed a moderate inhibitory effect Against Gram-negative bacteria (S. marcescens and E .coli) . The mechanism of this antibacterial action was further investigated by Time-Kill and electron microscopy studies, Escherichia coli and Methicillin-resistant Staphylococcus aureus (MRS A) were used as Gram negative and Gram positive bacterial models, respectively. Time-Kill and electron microscopy observation confirmed the remarkable inhibitory activity of manuka essential oil against Gram-positive bacteria and the temperate inhibitory effect against Gram-negative bacteria. Manuka oil - MRSA treated cells showed considerable .rnorphological alterations including seriously damaged cells, marked cellular .lysis and free cellular contents while Manuka oil - E. coli treated cells .appeared shortened and distorted shapes and had some lose of their integrity. When manuka oil was added to exponentially growing Methicillin-resistant Staphylococcus aureus (MRSA) ~d E. coli a significant reduction in the MRSA cells viability was observed where.a less effect in E.coli was noticed.
... Tea tree oil is considered as the strongest aromatherapeutic antimicrobial agent. It is used in the treatment of respiratory diseases, persistent gynecological infections, and dermatology inter alia [7,21]. Tea tree oil strongly inhibits the proliferation of Gram-positive and Gram-negative bacteria, including those particularly resistant to antibiotics such as Pseudomonas aeruginosa. ...
Article
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Volatile or essential oils - aetherolea are secondary plant metabolites containing different compounds. The oils have wide therapeutic action. Strong antiseptic activity of essential oils has been known all over the world for many centuries. A large number of essential oils and their constituents have been investigated for their microbial properties against some bacteria, fungi, viruses and protozoa. G-positive bacteria are generally more susceptible to essential oils than G-negative ones. So far there been no reports on growing resistance of bacterial strains to oils. The antimicrobial and immunostimulatory activity of essential oils is strictly connected to their chemical composition. Essential oils of thyme, oregano, cinnamon, tea tree, eucalyptus, lavender, salvia and mint, were found to possess the strongest antibacterial and antifungal properties. Essential oils show high activity against even in the methycillin-resistant staphylococci, vancomycin-resistant streptococci and against Gram-negative ones. Thyme and eucalyptus oils have been the most inhibiting against respiratory tract pathogens. Oregano oil appears to have a wide spectrum of antibiotic activity against microflora and this is recommended in fighting intrahospital infections. The article clearly demonstrate that essential oils presents a great potential for medical procedures and for pharmaceutical industries.
... Their folk wisdom has been passed down for generations, and TTO antimicrobial activity is now being validated through an extensive scientific research Mondello et al., 2003Mondello et al., , 2006. More recently, the European Medicine Agency has recognized its traditional use (Lis-Balchin et al., 2000;Saller et al., 1998) and edited a community herbal monograph on Melaleuca aetheroleum (EMA, 2013); TTO has been used worldwide for herbalist or pharmaceutical products (SCCP, 2008) including suppositories for the treatment of vaginal candidiasis. However, there is still little evidence that TTO-based preparations could be safe and efficacious for clinical use in a complex microbial environment such as the vaginal one. ...
Article
The aim of this work is to evaluate the in vitro microbicidal activity of vaginal suppositories (VS) containing tea tree oil (TTO-VS) towards Candida spp. and vaginal probiotics. A total of 20 Candida spp. strains, taken from patients with vaginitis and from an established type collection, including reference strains, were analysed by using the CLSI microdilution method. To study the action of VS towards the beneficial vaginal microbiota, the sensitivity of Bifidobacterium animalis subsp. lactis (DSM 10140) and Lactobacillus spp. (Lactobacillus casei R-215 and Lactobacillus acidophilus R-52) was tested. Both TTO-VS and TTO showed fungicidal activity against all strains of Candida spp. whereas placebo-VS or the Aloe gel used as controls were ineffective. The study of fractional fungicidal concentrations (FFC) showed synergistic interaction with the association between Amphotericin B and TTO (0.25 to 0.08 µg/ml, respectively) against Candida albicans. Instead, the probiotics were only affected by TTO concentration ≥ 4% v/v, while, at concentrations < 2% v/v, they remained viable. TTO-VS exhibits, in vitro, a selective fungicidal action, slightly affecting only the Bifidobacteriun animalis strain growth belonging to the vaginal microbiota. In vivo studies are needed to confirm the efficacy to prevent acute or recurrent vaginal candidiasis. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.
... v/v) showed 80% activity on DPPH radicals. However, Lis-Balchin et al.[11]has demonstrated that essential oil of the Australian tea tree (M. alternifolia) showed no antioxidant ...
Article
The essential oil of tea tree (Melaleuca alternifolia) is widely used in traditional Australian medicine for skin lesions and infected injuries. In the present study, we investigated the chemical composition, cytotoxicity and its biological activities. The composition of the oil was analyzed by GC-MS. {\beta}-Terpinene (20.87%), {\alpha}-pinene (17.60%), p-cymene (11.23%), 3-carene (10.40%), trans-anethole (8.47%) and limonene (4.65%) were the major components in the oil. The results tested by MTT assay indicated that the oil showed no cytotoxic effect, at concentrations up to 5%, for less than 3h. The antiradical capacity was evaluated by measuring the scavenging activity of the essential oil on the 2,20-diphenylpicrylhydrazyl (DPPH) and 2,2`-azino-bis 3-ethyl benzothiazoline-6-sulfonic acid (ABTS) radicals. The oil was able to reduce the both radicals dose-dependently, and the concentration required for 50% reduction (RC_{50}) against ABTS radicals (1.6?0.02%) was slightly lower than DPPH radicals (2.6?0.29%). The direct contact and vapor-phase antibacterial activity of the oil were also evaluated using disc diffusion method against Staphylococcus aureus, Streptococcus mutans, Listeria monocytogenes, Acinetobacter baumannii, Escherichia coli, and Vibrio parahaemolyticus. All the Gram-negative bacterial strains tested showed more sensibility to the oil than the Gram-positive strains when compare to the effect of gentamycin. On the other hand, the vapor phase of the essential oil against S. aureus exhibited strongest inhibitory effect.
... Myrtaceae há uma grande variedade de princípios ativos contra microrganismos, incluindo óleos essenciais, flavonóides (SLOWING et al., 1994;LIS-BALCHIN et al., 2000;HERNÁNDEZ et al., 2000) e taninos (SCALBERT, 1991;DJIPA et al., 2000); . ...
Article
Estadual Paulista como parte dos requisitos para a obtenção do título de Doutor em Ciências Biológicas (Área de Concentração: Microbiologia Aplicada).
... They are woody plants with generally entire leathery evergreen leaves with opposite exstipulates, 3 and constitute an important source of essential oils, flavonoids, tannins and other phenolics with biological activities including antibacterial, antifungal or anti-inflammatory properties. 4,5 Many members of this family share similar features and these result in the complexity of their taxonomy and nomenclature and may account for the lack of interest in the study of this plant family in the last decades. The level of specific diversity for the Myrtle family is estimated to have increased by 43% for the last two decades between publication of the first and latest editions of Mabberley. ...
Article
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The Eugenia genus is comprised of about 1011 species which share similar features resulting in the complexity of its taxonomy and nomenclature. E. crassipetala, E. kanakana, E. tinifolia and two undescribed Eugenia species all medicinal and endemic to Mauritius Islands were characterized using their phytochemical, bioactive and molecular profile. Biological activity was assessed using the broth microdi-lution assay and the DPPH assay. Significant minimal inhibitory concentration values of E. crassipetala against E. coli (1.56 mg/mL), E. kanakana against P. mirabilis (0.55 mg/mL) and E. spp (small) against S. aureus (0.43 mg/mL) validates the antibacterial ability of these plant extracts and could be attributed to their high content of antioxidants (flavonoids and phenols). Genetic diversity among these five species was assessed by amplification of genomic DNA using 60 RAPD and 25 ISSR markers. Hierarchical cluster analysis vali-dates the uniqueness of each Eugenia species with E. crassipetala and E. tinifolia forming a separate cluster. Comparative analysis of phy-tochemical composition and bioactivity corre-late with the branching pattern of the species in the dendogram.
... flexuosus and M. alternifolia) has also been evaluated against planktonic cells in some previous studies. Oussalah et al. (2007), for example, found that C. flexuosus EO showed antibacterial effect against L. monocytogenes, E. coli O157: H7, S. aureus and Salmonella Typhimurium; while Lis-Balchin et al. (2000) and Gustafson et al. (1998), respectively, observed that M. alternifolia EO was effective against L. monocytogenes and E. coli. However, it is important to emphasize that this was the first time that the EOs of C. cassia, C. flexuosus and M. alternifolia were tested in combination against bacterial cells. ...
Article
The antibacterial potential of essential oils (EOs) from Cinnamomum cassia bark and Melaleuca alternifolia and Cymbopogon flexuosus leaves was evaluated against planktonic and sessile cells of enteropathogenic Escherichia coli (EPEC) and Listeria monocytogenes. The EOs were tested singly and in different combinations of equal percentages: mixtures of two (1:1 in v/v) and three EOs (1:1:1 in v/v/v). The minimal inhibitory concentrations (MICs) were determined against planktonic cells and the anti-biofilm activity was verified against bacterial cells adhered in the wells of polystyrene microplates. These initial tests indicated the EO of C. cassia as a potential anti-biofilm agent, and their effect was studied against sessile cells of biofilms formed on stainless steel surface under agitation and static conditions. For both bacterial species, a solution containing 2% (v/v) of C. cassia EO was effective against the biofilm formed under static conditions, because the counts obtained were below the detection level of the plate count method employed. Although the biofilm of L. monocytogenes showed a decreased number of adhered cells after formation under agitating conditions (p < 0.05), it was surprisingly more resistant to the EO of C. cassia than the biofilm formed under static conditions (p < 0.05). All of the EOs and combinations tested presented antibacterial activity, almost against planktonic cells; however, the EO of C. cassia showed to be the most effective as a potential agent for the production of sanitizers for biofilm control in the food industries.
... Furthermore, the high level of bioactive compounds in Manuka leaves is responsible for the powerful antibacterial and antifungal activities of Manuka essential oil [4]. This can be proven by the healing properties of Manuka essential oil-containing products to treat various skin disorders such as ringworm, acne, eczema, athlete's foot, nail fungus, seborrheic dermatitis, and Candida Albicans [4][5][6][7][8]. Given all this, it might be of great interest to investigate the extraction of total phenolic compounds from Manuka leaves. ...
Article
Manuka tree (Leptospermum Scoparium) is the most widespread native shrub in New Zealand and has an economic impact as a source of honey and essential oils. In the present study, eight types of DESs based on choline chloride (ChCl) and tetrabutylammonium chloride (TBAC) as hydrogen bond acceptors (HBAs) in combination with different polyalcohols and carboxylic acids as hydrogen bond donors (HBDs) were used to assess the extraction of polyphenolic compounds in terms of total phenolic content (TPC) from dried Manuka leaves. ChCl: ethylene glycol DES showed the highest efficiency in the extraction of the polyphenolic compounds (56.87 mg GAE/g DW) followed by ChCl: lactic acid DES (52.51 mg GAE/g DW) and ChCl: 1, 3-propanediol DES (50.67 mg GAE/g DW). Furthermore, the mentioned DESs revealed a better extraction efficiency for polyphenolic compounds than ethanol as a benchmark solvent. Among the successful DESs, ChCl: lactic acid DES was preferred and studied further for optimization using response surface methodology. The highest TPC (59.82 mg GAE/g DW) was extracted at optimum conditions (extraction temperature 50.00 ℃, biomass % 5.07 and extraction time 1.07 h). Besides, the extracted polyphenolic compounds showed good stability in ChCl: lactic acid DES over eight days of storage. Moreover, after four extraction cycles using the DES, 154.65 mg GAE/g DW of TPC advises a possible scaling up of the potential DES. The antioxidant activity of extracts was evaluated using DPPH and FRAP assay. ChCl: ethylene glycol DES extract showed better free radical scavenging activity (12.78 µg TE/ml) while ChCl: lactic acid DES extracts gave higher ferric reducing power (199.78 µg TE/ml) at the same extract concentration with both being higher than the extract obtained by ethanol.
... Endophytic bacteria are promising biocontrol agents (Berg et al., 2005) because they occupy internal living tissues of plants and may be in close proximity to plant pathogens, Medicinal plants harbour endophytic bacteria that can produce unique bioactive compounds and can be used as biocontrol candidates (Köberl et al., 2013;Li et al., 2014;Abdallah et al., 2016). Leptospermum scoparium (Myrtaceae) is a New Zealand medicinal plant that produces essential oils with antimicrobial properties against the food spoilage bacterium, Bacillus subtilis and the methicillin-resistant and human pathogenic bacterium Staphylococcus aureus (Lis-Balchin et al., 2000;van Klink et al., 2005). Although, the biocontrol potential of bacterial endophytes in L. scoparium has not been studied, parallels with international research suggest that L. scoparium is likely to harbour endophytic bacteria that can resist the antimicrobial compounds in the host plant vascular system and perhaps contribute to the protection against plant bacterial pathogens. ...
Article
Pseudomonas syringae pv. actinidiae (Psa) is the causal agent of bacterial canker in kiwifruit (Actinidia deliciosa). Mānuka (Leptospermum scoparium) is a New Zealand medicinal shrub that produces essential oils with antimicrobial properties. The aim of this study was to determine whether endophytes from L. scoparium could be transferred to A. deliciosa and maintain their biocontrol activity. Five endophytic bacteria showed antagonism against Psa in vitro. The endophytic bacteria possessed multiple antibiotic producing genes, such as phenazine, 2,4-DAPG, and hydrogen cyanide, compounds that are known to inhibit growth of bacterial plant pathogens. Spontaneous chloramphenicol mutants and BOX-PCR fingerprinting were used to monitor endophytic colonisation of antagonistic bacteria in planta. Three endophytic bacteria were transmissible to A. deliciosa by wound inoculation where they inhibited colonisation by Psa and reduced disease severity in two different commercial cultivars.
... Eucalyptose oil is used as an anti-microbial element in different kinds of cream, soap and toothpaste (17). (18) showed in his study that the volatile oil of the medicinal plant Eucalybtus austral have antifungal effect against Candida albicans and refer to the content of this volatile oil that it is composed mainly of oxygenated monoterpenes. ...
Article
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The present study was designed to evaluate the inhibitory effect of the different concentration (200, 400, 800) mg/ml from local plant ethanolic extract leaf (Eucalybtus austral) against the growth of Candida albicans in culture media by using of agar well diffusion method, it which take from supargingival plaques gum and effect of age, sex and smoker state. The result showed that the extract (Eucalybtus austral) was more effective concentration 800mg/ml, comparative with effect other concentration from of( Nystatin and Clotrimazole). The statistical analysis by using Chi- squired test at level (P<0.05) showed that the sex and smoker state were a significantly preeminence
... 21 Moreover, in previous studies all of these EOs, employed alone, showed effective activity against Listeria monocytogenes. 13,[22][23][24] To the best of our knowledge no studies are available in the literature that have focused on the evaluation of the synergistic activity of the three EOs. For this reason, the main goal of our research was to test the three EOs combined together against Listeria monocytogenes and, secondly, to compare their activities with those obtained by employing binary combinations (mixtures of two EOs) and those obtained with the individual EOs on their own. ...
Article
Essential oils (EOs) are categorized as having antimicrobial, insecticidal, and antioxidant activities. For their antibacterial activity, EOs are widely studied as alternatives to antibiotics in human and veterinary medicines. The inhibitory and bactericidal activities of three EOs (Cinnamomum zeylanicum, Leptospermum scoparium, and Satureja montana) were determined against Listeria monocytogenes ATCC 7644. The chemical compositions of the EOs were determined through gas chromatography mass spectrometry (GC‐MS). Essential oils were tested alone or in binary and ternary combinations for both their inhibitory and their bactericidal activities. Binary and ternary mixtures were tested through a chequerboard assay, and thus fractional inhibitory and fractional bactericidal concentration indices were obtained in relation to the activity of each EO alone. The chemical composition of each EO had different percentages of the main classes of compounds. EOs showed high levels of monoterpenes (hydrocarbons and oxygenated), sesquiterpenes (hydrocarbons and oxygenated), and phenylpropanoids for winter savory, manuka, and cinnamon, respectively. Several synergistic activities against Listeria monocytogenes were demonstrated in binary and ternary mixtures of the EOs. Mixtures of the EOs tested showed potential for use as antibacterial products; moreover, because of the synergistic activities the mixtures could be used in lower quantities than individual EOs on their own. Essential oils are often effective antimicrobial agents. Their combination amplifies their effects. This investigation sheds light on the synergistic activity of binary and ternary mixtures of essential oils against Listeria monocytogenes.
... and MBC:0.12% vs. MRSA [109,114,117,121,122]; and MIC: 1 mg/mL vs S. pyogenes [120]. Apart from its antibacterial effects, MO possesses good anti-inflammatory and antioxidant properties that could potentially offer value when treating skin infections [108,123,124]. ...
Article
Full-text available
Impetigo (school sores) is a common superficial bacterial skin infection affecting around 162 million children worldwide, with the highest burden in Australian Aboriginal children. While impetigo itself is treatable, if left untreated, it can lead to life-threatening conditions, such as chronic heart and kidney diseases. Topical antibiotics are often considered the treatment of choice for impetigo, but the clinical efficacy of these treatments is declining at an alarming rate due to the rapid emergence and spread of resistant bacteria. In remote settings in Australia, topical antibiotics are no longer used for impetigo due to the troubling rise of antimicrobial resistance, demanding the use of oral and injectable antibiotic therapies. However, widespread use of these agents not only contributes to existing resistance, but also associated with adverse consequences for individuals and communities. These underscore the urgent need to reinvigorate the antibiotic discovery and alternative impetigo therapies in these settings. This review discusses the current impetigo treatment challenges in endemic settings in Australia and explores potential alternative antimicrobial therapies. The goals are to promote intensified research programs to facilitate effective use of currently available treatments, as well as developing new alternatives for impetigo.
... From some of the tested EOs, we could have expected a greater effectiveness in antibacterial action in view of the data reported in literature; however, the differences among the compounds are probably linked to their different biological activities [46]. Hence, mixtures of the EOs could also be considered to determine their potential synergistic action. ...
Article
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This study aimed to test in vitro the antimicrobial activity of 11 essential oils (EOs) against four methicillin-resistant Staphylococcus pseudintermedius (MRSP) and four methicillin-susceptible S. pseudintermedius (MSSP) clinical isolates. The obtained findings demonstrated a clear in vitro efficacy of some tested EOs against both MRSP and MSSP strains. Particularly, modal minimum inhibitory concentration (MIC) values ranging from 1:2048 v/v for Melissa officinalis against an MSSP strain to 1:256 v/v for Cymbopogoncitratus against all MRSP strains were observed. The best results, highlighting a modal MIC value of 1:1024 v/v for all tested isolates, was provided by Cinnamomum zeylanicum. Intriguingly, Cinnamomum zeylanicum showed, in many cases, a correspondence between minimum bactericidal concentration (MBC) and MIC values, indicating that the inhibiting dose is also often bactericidal. Moreover, a mild antibacterial and bactericidal activity against both MRSP and MSSP isolates was detected for the other tested EOs. Considering the zoonotic potential of S. pseudintermedius and the increased dissemination of multidrug-resistant strains, the employment of EOs could be useful for the treatment of canine pyoderma. Since antibiotic resistance has become the most urgent issue, from the perspective of the One Health initiative, alternative therapeutic approaches are desirable to limit the use of antibiotics or to improve the efficacy of conventional therapies.
... The antifungal activity of C. deodara oils may be mainly attributed due to its richness of monoterpenes, whereas wide variety of essential oils are known to possess antifungal properties and in many cases, this activity is due to the presence of active constituents, such as monoterpenes, sesquiterpenes, and related alcohols, hydrocarbons, and phenols [35]. Additionally, monoterpenes diffuse into pathogens and damage cell membrane structures resulting in its death [36,37]. ...
Article
Full-text available
A focus on evaluation of in vitro antifungal activity of essential oil of Cedrus deodara (bark), against fungus Curvularia lunata was studied. In this study, the essential oil was extracted via hydro distillation method, further chemical compositions were identified by GC–MS and antifungal potential was assessed against three pathogenic fungal strains viz., Alternaria alternata, Curvularia lunata and Bipolaris spicifera through poison food technique. The essential oil showed strong antifungal potential against Curvularia lunata, further leading to isolation of antifungal fraction using TLC bioautography against Curvularia lunata, the identification revealed the presence of ten molecules in antifungal fraction identified through GC–MS. Additionally, molecular docking study was applied to validate antifungal activity and results predicts strong binding affinity of isolated antifungal molecules with an important virulence factor of Curvularia lunata, a melanin biosynthetic enzyme trihydroxy naphthalene reductase (PDB ID-1YBV) confirming it antifungal potential. Thus, obtained results suggested the importance of essential oil from Cedrus deodara (bark) as a beneficial native source of the compounds with antifungal properties.
... As an antidote to a wide range of microorganisms. This activity is mainly attributed to the most important chemical compounds such as the presence of cinnamaldehyde and Eugenol compounds (5), as well as volatile oils that used as antimicrobial and antifungal agents in creams, toothpaste, and soaps (6). Recently many studies are shown the possible effects of two compounds isolated from C. cassia against myocardial ischemia, aldehyde cinnamic and cinnamic acid (7), indicating that cinnamon also has the adequacy to be used to treat cardiovascular disease. ...
Article
Aqueous and ethanolic extracts of ginger )Zingier officinale) and (Cinnamomum zeylanicum) were used to investigate an antifungal activity against food spoilage fungal pathogens. Study of the inhibitory effect of these extract was done separately against Aspergillus niger and Penicillium notatum isolated from (tomato pasts, cheese) the samples were cultured on Sabouraud's dextrose agar (SDA) at pH 5.6 and 28°C. In this study, results had shown that the extracts of Both plant demonstrated antifungal activity. When compare extracts of the two plants, C. zeylanicum extracts showed higher inhibition activity than (Zingiber officinale) extracts significantly. Ethanolic extracts of these tow plants gives significantly inhabitation in the mycelia growth of fungi more than their aqueous extracts (16-22), (19-25)mm, P. noitatum and A. niger respectively while the inhibitory observed by the aqueous extract (5-6) mm against A. niger for (6-8) mm. Against P. notatum was the most affected by all extracts while A. niger was the least susceptible. There was a significant difference (P=0.05) between groups in the antifungal activities of tested fungi, and the effectiveness of ethanolic extracts was increased with increase in their concentrations. The ability of these extracts to inhibit the growth of the two fungi must take into consideration an indication of the antifungal potency of cinnamon and Zingiber officinale, that makes them the candidate for the production of antifungal agents.
...  Manuka oil has a consistently high antioxidant activity and a marked antifungal effect (Balchin, 2000). ...
... Kunzea from Aotearoa New Zealand) include phloroglucinols (Bloor 1992) and terpenes (Perry et al. 1997;Porter and Wilkins 1999). Kānuka essential oils and/or purified compounds have activity against bacteria (Lis-Balchin et al. 2000;Chen et al. 2016;Prosser et al. 2016), viruses (Bloor 1992) and fungi (Chen et al. 2016). However, we are the first to report anti-Phytophthora activity of kānuka, and this also seems to be the first report of flavanones from a New Zealand species of Kunzea. ...
Article
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Kauri is an ecologically important and culturally treasured tree species in Aotearoa New Zealand. It is under threat from the pathogenic oomycete Phytophthora agathidicida, which causes kauri dieback disease. We hypothesised that mātauranga Māori (Māori knowledge) of kauri forest health could be used to identify native plants that produce anti-Phytophthora compounds. We tested this hypothesis by using knowledge descended from Te Whare Wananga o Ngāpuhi to select and screen four native plants for activity against P. agathidicida and also P. cinnamomi (a broad host-range pathogen). Extracts of kānuka (Kunzea robusta) were active against various life cycle stages. Bioassay-directed isolation led to three flavanones, previously unreported from New Zealand Kunzea, as the main bioactives. These compounds have not previously been reported as having anti-Phytophthora activities. They inhibited P. agathidicida zoospore germination with IC50 values of 1.4–6.5 µg/mL, making them the most potent inhibitors reported against this stage of the life cycle. The three flavanones also inhibited zoospore motility at 2.5–5.0 µg/mL, and showed some inhibition of mycelial growth at 100 µg/mL. They were generally less active against P. cinnamomi. Overall, the results from this study emphasise the value of using mātauranga Māori in the response to kauri dieback.
... The essential oil of Melaleuca (Melaleuca alternifolia), also called tea tree oil, has in its composition terpinen-4-ol, which has antifungal, bactericidal, antiviral, antiinflammatory, anesthetic, analgesic, antineoplastic, insecticidal, and antiparasitic properties. Several studies addressing traditional medicine and phytopathogen control report the antimicrobial activity of this oil (Lis-Balchin et al., 2000;Hammer et al., 2003;Caldefie-Chezet et al., 2006;Baldissera et al., 2014;Souza et al., 2015). ...
Article
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The fungus Lasiodiplodia theobromae causes black rot in maize seeds, leading to losses in crops production. The fungicides used in the control of black rot are highly toxic, requiring the development of less harmful control techniques. This work evaluates the effect of Melaleuca essential oil against L. theobromae, both under in vitro conditions and on maize seeds. The in vitro experiment compared the growth of the fungus in PDA culture medium containing the oil at 0.25, 0.50, 075, and 1.0%, a negative control, and positive control (Thiram fungicide). The in vivo experiment analyzed the incidence of L. theobromae in maize seeds treated with the essential oil at 0.50, 0.75, and 1.00%, and in the negative and positive controls. After the treatments of seeds, we inoculated them with the fungus and performed sanity tests. In the in vitro test, Melaleuca essential oil inhibited 100% of mycelial growth in the 0.75% concentration. In the in vivo test, the oil at 1.0% concentration reduced the incidence of fungus in the seeds to 45%, being more effective than the synthetic fungicide. Thus, Melaleuca oil has a strong potential as a control agent against fungus L. theobromae in maize seeds.
... (Myrtaceae), is a New Zealand indigenous shrub. Essential oils are produced from foliage of this plant commercially for their antimicrobial properties (Perry et al. 1997;Lis-Balchin et al. 2000). Mānuka from different regions of New Zealand have qualitatively distinct essential oil compositions, i.e. chemotypes which differ greatly in the relative proportions of different compounds (Perry et al. 1997;Porter and Wilkins 1990). ...
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Leptospermum scoparium or mānuka is a New Zealand native medicinal plant that produces essential oils with antimicrobial properties. This study investigated the arbuscular mycorrhizal fungi (AMF) community in mānuka by culture dependent (trap culture) and independent (denaturing gradient gel electrophoresis) approaches. Furthermore, to assess whether mycorrhizal inoculation could alter growth and essential oil composition of mānuka, plants of a single regional chemotype were grown in unsterilized soil and inoculated with five AMF isolates. Leaf essential oil compositions and yields were determined by microscale solvent extraction and gas chromatography-mass spectrometry (GC-MS) analysis. AMF inoculation significantly increased growth compared to uninoculated plants. Qualitative i.e. different relative proportions of compounds, which are distinctive in chemotypes and quantitative (i.e. absolute concentrations of compounds, expressed as mg/g of dry leaf or equivalent) effects of AMF inoculation on mānuka essential oil composition depended on the isolate. AMF inoculation modified the Gammaproteobacterial community on roots and this may have contributed to changes in essential oil composition. Overall, these results demonstrated that AMF can improve the growth of mānuka and affect plant secondary metabolites in leaves, which would be valuable in commercial essential oil production from plantation-grown mānuka.
... Eucalyptus spp. possess strong antimicrobial property (Dikshit and Hussain, 1984;Prassad et al., 1986;Lis-Balchin et al., 2000;Sartorelli et al., 2007). ...
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Ethnopharmacological relevance: Bacterial endometritis is one of the major causes of reproductive disorders including infertility in farm animals. Antibiotics are generally used for treatment of such disorders but now a days residues of antibiotics are of great public health concern, therefore, phytoremediation is being considered as an alternative to use of antibiotics. Aim of the study: Present study was undertaken to investigate the efficacy of Eucalyptus robusta leaves methanolic extract against endometritis along with the possible mechanism of action especially targeting inflammatory biomarkers. Materials and methods: Bacterial endometritis was produced using clinical isolates of E. coli and Staphyloccocus aureus from bovines (cows and buffaloes) endometritis cases. After seven days of inoculation of the mixed bacterial culture, endometritis was confirmed based on the presence of visible pus and edema, thinning of endometrial lining and presence of large number of polymorphonuclear cells and bacterial load in uterine flushing. Female Wistar rats were divided in to five groups namely control, sham-operated, endometritis, endometritis plus Eucalyptus leaves extract and endometritis plus cefixime. Serum specific inflammatory biomarkers (interleukin-1β, interleukin-10, tumor necrosis factor-α, intercellular adhesion molecule-1, serum amyloid A) and myleoperoxidase, toll like receptors-4 and -9, inducible nitric oxide synthase, nitric oxide, cyclooxygenase 1 and 2 were estimated in uterine tissues using ELISA kits. Results: Interleukin-10, serum amyloid A, myleoperoxidase, toll like receptors-4 and-9, cyclooxygenase-2, inducible nitric oxide synthase and nitric oxide were significantly increased while non significant increase in interleukin-1β, cycloxygenase-1 and intercellular adhesion molecule-1 were observed but level of tumor necrosis factor-α was found decreased in rats of endometritis group. Histopathological lesions in uterus showed efficient induction of endometritis by presence of inflammatory cells which are lessened effectively after treatment with Eucalyptus leaves extract. Eucalyptus robusta leaves extract produced curative and protective effect against endometritis and results were comparable to or even better than cefixime. Conclusions: Eucalyptus robusta leaves extract possess promising antibacterial activity and efficacy against experimental endometritis and, therefore, holds promising potential for development of effective formulation for treatment of endometritis in animals.
... 11 Essential manuka oil, obtained from the manuka tree (Leptospermum scoparium), has antibacterial properties against Staphylococcus aureus and other bacteria, as well as antifungal effects. 12 Its components also show antiviral effects against Herpes simplex virus type-1 and 2. 13 Additional studies described a positive effect of manuka oil against UVB radiation-induced premature aging in mice. 14 As mild cleansing agent the botanical cleanser contains for example cocoyl glutamate and sodium cocoyl glutamate derived from coconut oil. ...
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Background Elevated levels of skin sebum are associated with the growth of Propionibacterium acnes. Intensive degreasing of the skin reduces Propionibacterium acnes but also may cause skin irritation. Aims We assessed the degreasing effect and skin tolerability of a botanical face cleanser with hops and willow bark extract and disodium cocoyl glutamate as mild cleansing agent compared to a standard face cleanser with sodium laureth sulfate (SLES). Materials and Methods A total of 21 healthy volunteers with normal to oily skin were enrolled in this study. Both cleansers were applied twice a day on the left or right side of the forehead for 15 days in a standardized manner. Bioengineering measurements were performed on day 8 and 15 and on day 17 after an application break of 48 hours. The sebum level was determined using a Sebumeter®, and skin redness was measured using a Mexameter®. Results The botanical face cleanser significantly reduced the sebum level (P < .01) in the test area on day 17. The SLES containing cleanser showed a statistically relevant degreasing effect already on day 15, but after the application break the sebum level increased again on day 17. None of the cleansers caused skin irritation as determined by skin redness measurements. Conclusions In contrast to the SLES containing cleanser, the botanical skin cleanser with hops and willow bark extract had a continuous degreasing effect without reactive seborrhoe after the treatment break. Skin cleansing without SLES might be advantageous for sensitive skin.
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Preprint
Highly pathogenic avian influenza virus (HPAIV) H5N1 is an endemic disease in Egypt and severe outbreaks have been reported even in vaccinated flocks. Several H5 vaccines have failed to protect birds against Egyptian H5N1 virus. In this study, the antiviral effect of green tea extract (GTE) in combination with inactivated H5N1 vaccine was evaluated. GTE found to be safe at high concentration on Vero cells and decrease the CPE on infected cells. In vivo, specific pathogen free chickens were allocated into four groups, 15 birds each. Negative control group, positive control group, vaccinated group, vaccinated group supplied by GTE in drinking water (5gm/L). Blood samples were collected weekly and tested using (HI) test. Lung tissue specimens collected for histopathology and immunohistochemistry. Interestingly, vaccinated non-treated birds exhibited severe post vaccinal reaction and deaths. GTE in combination with inactivated vaccine increased HI titer one-week post vaccination, and no deaths were recorded in this group. Moreover, treated chickens did not excrete virus in swab samples and minimal antigen and pathological changes were reported in its lungs. The addition of GTE prevent the shedding of the virus and achieve complete protection against HPAI.
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Sustainable stormwater treatment systems remove pollutants using low energy, low maintenance and low cost solutions. Inactivation due to biotic stressors is one of the processes that govern the removal of faecal microorganisms in these systems. One such stress is the possible production of antimicrobial compounds by plants growing in sustainable stormwater treatment systems, potentially enhancing the removal of faecal pathogens. To this end, this study has investigated the antimicrobial potential of 17 Australian native plant species that are suitable for application in these systems but have not been tested for their antimicrobial activity within their seed exudates, seed extracts and/or seedling extracts. The extracts and exudates were tested using the agar well diffusion method. Nine of the selected plant species inhibited the growth of Escherichia coli. Among of the antibacterial plants, Melaleuca ericifolia, which has been previously applied in stormwater treatment systems, can be a suitable candidate for further study as it demonstrated antibacterial activity within all tested components. This species should be utilised in stormwater treatment facilities due to its effective nitrogen uptake, maintenance of hydraulic conductivity, and due to its potential effectiveness at inactivating microbial pathogens.
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A proposta deste estudo foi realizar uma revisão sistemática da literatura, sobre mucosite oral (MO) em pacientes submetidos à radioterapia e quimioterapia para tratamento de tumores na região de cabeça e pescoço, de modo a levantar evidências científicas sobre prevenção e tratamento destas complicações. Os procedimentos metodológicos foram baseados nas recomendações da Cochrane Collaboration. Após a realização da busca nas bases de dados, obteve-se 3203 artigos, destes, 22 foram selecionados. Sete reportaram a terapia com Laser, três artigos avaliaram o uso do Mel, dois sobre o uso de Palifermin®, além de estudos sobre o Actovegin® endovenoso, enxaguatórios bucais a base de calêndula, fenilbutirato, clorexidina e cloreto de cetil-piridino. Outros abordaram o uso da radioterapia pela manhã, a crioterapia, o suco de aloe vera, o papel do Lactobacillus Brevis, do maleato de irsogladina e do fator de crescimento epidérmico. Os resultados obtidos nesta investigação apontam que a terapia com laser de baixa potência ainda é a mais indicada na prevenção e tratamento da mucosite oral. Entretanto, ainda é necessária a continuidade dos estudos que visam responder à temática, visto que, quanto maior for o esforço nessa área, maiores serão as chances de reduzir o número de indivíduos acometidos pela MO.
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In the present study, the chemical compositions and antimicrobial and antioxidant activities of commercially available essential oils in Korea were investigated. The essential oils were analyzed by gas chromatography-mass spectrometry (GC-MS). The results demonstrated that they exhibit a broad spectrum of antimicrobial activities against gram positive, gram negative, and multidrug resistant (MDR) strains. The antimicrobial activity of five of the essential oils against 40 organisms was assessed using the minimum inhibitory concentration (MIC). The MIC values were in the ranges of 0.0625-0.5% (v/w) for lemongrass and manuka, 0.03125-1.0% (v/w) for tea tree, 0.0625-1.0% (v/w) for thyme, and 1-4% (v/w) for ravensara, depending on the pathogens studied. This study revealed that, among the essential oils tested, lemongrass and thyme oil showed broad antimicrobial activity against infectious bacteria. The antioxidant activities and the reducing power of the essential oils were determined with a 1, 1-diphenyl-2-picrylhydrazyl (DPPH) assay. Thyme oil exhibited the strongest antioxidant activity comparing with ascorbic acid. This is the first report on the chemical compositions and antimicrobial activities of commercially available essential oils against infectious bacteria and MDR strains acquired from Korean hospitals.
Book
The second edition of this book is virtually a new book. It is the only comprehensive text on the safety of essential oils, the first review of essential oil/drug interactions, and it provides detailed essential oil constituent data not found in any other text. Much of the existing text has been re-written, and 80% of the text is completely new. There are 400 comprehensive essential oil profiles and almost 4000 references. There are new chapters on the respiratory system, the cardiovascular system, the urinary system, the digestive system and the nervous system. For each essential oil there is a full breakdown of constituents, and a clear categorization of hazards and risks, with recommended maximum doses and concentrations. There are also 206 Constituent Profiles. There is considerable discussion of carcinogens, the human relevance of some of the animal data, the validity of treating an essential oil as if it was a single chemical, and the arbitrary nature of uncertainty factors. There is a critique of current regulations.
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Leptospermum scoparium (Mānuka) is the source of nectar for Unique Mānuka Factor (UMF) honey. The chemical component of interest to this study is dihydroxyacetone (DHA). DHA is the precursor for the chemical methylglyoxyl which is the main chemical responsible for the UMF activity in Manuka honey. Screening commercially bred plants for increased DHA synthesis in L. scoparium is a critical factor in growing the Manuka Honey industry in New Zealand. FT-Raman spectroscopy, in combination with principal component analysis and partial least squares regression analysis, was investigated as an analytical tool for building a screening model for DHA in the nectar of L. scoparium. Leaf samples of seven cultivars of the species L. scoparium were collected in an attempt to correlate metabolic factors in the plant with DHA synthesis in the nectar. Leaf material was analysed using Fourier transform-raman spectroscopy (FT-Raman). The DHA levels in nectar samples of the same cultivars were measured using standard LC-MS methods. This study showed that the application of multivariate analysis of FT-Raman spectra from leaf material is a useful tool to screen for DHA potential in L. scoparium. The PLS regression shows that we can screen for DHA concentrations in the range of 3300–7600 mg/kg plus or minus 20% standard error and can distinguish low medium and high DHA synthesis in the group of plants studied. The model for predicting DHA concentrations is influenced by a significant contribution from the spectral variance due to beta-carotene and other highly scattering compounds that are not directly correlated with UMF. Copyright © 2014 John Wiley & Sons, Ltd.
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The aim of this study was to characterize the chemical composition and to evaluate the antimicrobial and phytotoxic properties of the essential oils (EOs) obtained from leaves of Leptospermum petersonii chemotype "Variety B" and Eucalyptus gunnii, native to Australia. Geranyl acetate, γ-terpinene, geraniol, terpinolene, α-pinene, p-cimene, and linalool were the main components in L. petersonii EO, confirming also the existence of several chemotypes in such taxa; on the other hand, 1,8-cineole, trans-sabinene hydrate acetate, globulol, longicyclene, terpinolene, and camphene were present in major amounts in the E. gunnii EO. Chemical analysis of L. petersonii revealed that it belongs to the variety "B." E. gunnii EO showed good antibacterial activity, with an MIC of 0.5 and 2 µg/mL against Staphylococcus aureus, and Pectobacterium carotovorum, respectively. The activity of E. gunnii EO was stronger than L. petersonii EO, whose maximum MIC reached 5 µg/mL. E. gunnii and L. petersonii EOs were particularly effective in inhibiting the biofilm formation by S. aureus, already at a concentration of 0.01 µg/mL. The other strains were resistant to both EOs up to a dose of 0.05 µg/mL. The maximum inhibition on biofilm formed by P. carotovorum was recorded for E. gunnii EO, reaching a value of 93.12% at 1.0 µg/mL. This is the first manuscript which studies the biofilm inhibition by EOs and evaluates their effects on biofilm metabolism. Both EOs were more effective against P. carotovorum. In addition, even though L. petersonii EO 0.1 µg/mL was unable to inhibit biofilm formation by Escherichia coli, it decreased the metabolic activity of the biofilm to 78.55% compared to control; furthermore, despite it inducing a relatively low inhibition (66.67%) on biofilm formation, it markedly affected metabolic activity, which decreased to 16.09% with respect to the control. On the contrary, L. petersonii EO 0.5 µg/mL induced a 79.88% inhibition of S. aureus Frontiers in Microbiology | www.frontiersin.org 1 April 2020 | Volume 11 | Article 409 Caputo et al. Biological Activities of Two Essential Oils biofilm, maintaining a high metabolic activity (90.89%) compared to the control. Moreover, this EO showed inhibitory activity against radical elongation of Solanum lycopersicum and the germination of radish. On the contrary, E. gunnii EO showed no phytotoxic activity.
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La diarrhée infectieuse se distingue en trois grandes nosologies selon le germe qui la provoque: diarrhée bactérienne, la diarrhée virale, la diarrhée parasitaire. À celles-ci se rajoute une diarrhée plus ou moins chronique ou récidivante qui est celle de la diarrhée par surinfection d’un état de colopathie fonctionnelle.
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This study was carried out to determine the antimicrobial activities of leptospermone isolated from Leptospermum scoparium and its derivatives against six foodborne bacteria (Listeria monocytogenes, Salmonella typhimurium, Shigella flexneri, Shigella sonnei, Staphylococcus intermedius and Staphylococcus aureus), with a view to developing safer antimicrobial agents. The essential oil of L. scoparium seeds possessed potent antimicrobial activity against six bacterial strains. The antimicrobial compound of L. scoparium was isolated by chromatographic analyses and identified as leptospermone. To investigate the structure–activity relationships, the antimicrobial activities of leptospermone and its derivatives (2-acetyl-1,3-cyclohexanedione, 1,3-cyclohexanedione, 1,2,3-cyclohexanetrione-1,3-dioxime, 5,5-dimethyl-1,3-cyclohexanedione and 2,2,4,4,6,6-hexamethyl-1,3,5-cyclohexanetrione) were examined against six foodborne bacteria. Based on the MIC values, leptospermone (MIC 23.6–69.7 μg/mL), 1,2,3-cyclohexanetrione-1,3-dioxime (MIC 43.9–88.5 μg/mL) and 2,2,4,4,6,6-hexamethyl-1,3,5-cyclohexanetrione (MIC 43.9–88.5 μg/mL) exhibited antimicrobial activities against the six foodborne bacteria. These results indicated that leptospermone and its derivatives could potentially be developed as natural food preservatives, rather than using hazardous synthetic preservatives.
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Materials with antibacterial properties, that can be used as barrier materials, hygiene products, plasters or bandages, have been obtained by applying some systems consisting of essential oils incorporated in beeswax and beeswax/chitosan. The influence of oil, wax and chitosan amounts on emultion stability has been analyzed by optical microscopy. The controlled release of essential oils of Eucalyptus (EEO), Tea Tree (TTEO) and Sage (SEO) incorporated in beeswax and beeswax/chitosan from the treated material was estimated through UV/Visible spectrophotometric analyses. The antibacterial effect of the emulsions and of the materials obtained by treating them with these emulsions have been investigated against the Staphylococcus aureus ATCC 29213 and Escherichia Coli ATCC 25922 bacteria. Comfort performances (air and vapor permeability and hygroscopicity) for the treated materials have also been evaluated. The best antimicrobial activity and the highest amount of essential oil released in vitro were obtained for the treatment variants that contain 7.14 % beeswax and 26.67 % essential oil, and respectively 26.67 % essential oil, 3.33 % beeswax and 3.33 % chitosan. © 2015, The Korean Fiber Society and Springer Science+Business Media Dordrecht.
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Claims of benefits of aromatherapy for cancer patients include reduced anxiety levels and relief of emotional stress, pain, muscular tension and fatigue. The objective of this paper is to provide an updated descriptive, systematic review of evidence from pre-clinical and clinical trials assessing the benefits and safety of aromatherapy for cancer patients. Literature databases such as Medline (via Ovid), the Cochrane database of systematic reviews, Cochrane Central were searched from their inception until October 2010. Only studies on cancer cells or cancer patients were included. There is no long lasting effect of aromatherapy massage, while short term improvements were reported for general well being, anxiety and depression up to 8 weeks after treatment. The reviewed studies indicate short-term effects of aromatherapy on depression, anxiety and overall wellbeing. Specifically, some clinical trials found an increase in patient-identified symptom relief, psychological wellbeing and improved sleep. Furthermore, some found a short-term improvement (up to 2 weeks after treatment) in anxiety and depression scores and better pain control. Although essential oils have generally shown minimal adverse effects, potential risks include ingesting large amounts (intentional misuse); local skin irritation, especially with prolonged skin contact; allergic contact dermatitis; and phototoxicity from reaction to sunlight (some oils). Repeated topical administration of lavender and tea tree oil was associated with reversible prepubertal gynecomastia.
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Many terpenes used therapeutically or as flavor and fragrance materials are chiral compounds. Chiral separations have been advocated for the identification of adulteration of commercial oils as different essential oils and synthetic components contain different proportions of each enantiomer. An alternative method of assessing enantiomeric composition and thereby adulteration was tested using several biological parameters versus the bioactivity of the enantiomers of α-pinene. It was found that 18 out of 25 different bacteria were more affected by the (−) enantiomer of α-pinene; 19 out of 20 different L. monocytogenes strains were affected more by the (+) isomer and two of three filamentous fungi were affected more by the (+) enantiomer. The (−) enantiomer was more spasmogenic on smooth muscle than the (+) enantiomer. This suggests that differing bioactivities can indicate adulteration and also that medicaments containing chiral components should be formulated using the most suitable enantiomeric forms for each particular medical condition.
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Tea tree oil, or the essential oil of Melaleuca alternifolia, is becoming increasingly popular as a naturally occurring antimicrobial agent. The antimicrobial activity of eight components of tea tree oil was evaluated using disc diffusion and broth microdilution methods. Attempts were also made to overcome methodological problems encountered with testing compounds which have limited solubility in aqueous media. After assessing media with and without solubilizing agents, the disc diffusion method was used to determine the susceptibility of a range of micro-organisms to 1,8-cineole, 1-terpinen-4-ol, rho-cymene, linalool, alpha-terpinene, gamma-terpinene, alpha-terpineol and terpinolene. While the disc diffusion method lacked reproducibility, it was considered useful as a procedure for screening for antimicrobial activity. Terpinen-4-ol was active against all the test organisms while rho-cymene demonstrated no antimicrobial activity. Linalool and alpha-terpineol were active against all organisms with the exception of Pseudomonas aeruginosa. Minimum inhibitory and minimum cidal concentrations of each component against Candida albicans, Escherichia coli and Staphylococcus aureus were determined using a broth microdilution method. Modifications to this method overcame solubility and turbidity problems associated with the oil components and allowed the antimicrobial activity of each of the components to be quantified reproducibly. There was reasonable agreement between minimum inhibitory concentrations and zones of inhibition. These results may have significant implications for the future development of tea tree oil as an antimicrobial agent.
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Honey is a traditional remedy for dyspepsia, and is still used for this by some medical practitioners although there is no rational basis for its use. The finding that Helicobacter pylori is probably the causative agent in many cases of dyspepsia has raised the possibility that the therapeutic action of honey may be due to its antibacterial properties. Consequently, the sensitivity of Helicobacter pylori to honey was tested, using isolates from biopsies of gastric ulcers. It was found that all five isolates tested were sensitive to a 20% (v/v) solution of manuka honey in an agar well diffusion assay, but none showed sensitivity to a 40% solution of a honey in which the antibacterial activity was due primarily to its content of hydrogen peroxide. Assessment of the minimum inhibitory concentration by inclusion of manuka honey in the agar showed that all seven isolates tested had visible growth over the incubation period of 72 h prevented completely by the presence of 5% (v/v) honey.
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In view of the folk-medicinal usage of many New Zealand plants, the bioactivity of a number of commercial essential oils produced from local plants was studied in vitro against 25 different bacterial species, 20 different strains of Listeria monocytogenes and 3 filamentous fungi; the anti-oxidant activity was also determined as well as the pharmacological action on guinea-pig ileum. The family Myrtaceae was represented by samples of steam-distilled wood of Manuka (Leptospermum scoparium J.R.et G.Forst) and Kanuka (Kunzea ericoides (A.Rich.) J. Thompson) and Leptospermum petersonii Bailey syn. L. citratum from high altitude sites of South Island and the east coast of North Island had different but usually good antibacterial activity with poor antifungal action except for L. citratum, and variable antioxidant action; strong spasmogenic activity was shown by Kanuka, in contrast to a spasmolytic action of Manuka and L. petersonii. Other oils studied included New Zealand grown Tea tree (Melaleuca alternifolia (Maiden & Betche) Cheel), Totara (Podocarpus totara G. Benn. ex D. Don, Coniferae), which showed good and poor bioactivity respectively, and two species of Eucalyptus which showed variable results. The bioactivity of all these essential oils was compared against that of common herbs, grown locally.
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The pharmacology and antimicrobial action of selected commercial, plant essential oils was studied to relate bioactivity with the chemical components. Spasmogenic action induced by oils on Guinea-pig ileum in vitro was related to a high terpene content, mainly the pinenes, β-cymene, and limonene. Many of the essential oils that induced spasmogenic activity were also strong antibacterial agents. A correlation was observed between spasmogenetic action of essential oils on smooth muscle and stimulating action in man in vivo as measured by contingent negative variation studies. Different samples of the same essential oil often showed differences in the chemical composition as well as bioactivity. Adulteration of essential oils can therefore be shown by bioactivity, which may be more relevant if the essential oils are used for medical or paramedical purposes including aromatherapy using just the aroma or together with body massage.
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Geranium oil is one of the most frequently used oils in aromatherapy. However, there is a large and diverse variation in the composition of commercial geranium oil, which depends only partly on its country of origin. The bioactivity of 16 commercial samples of geranium oils was assessed in vitro against 25 different bacteria, 20 Listeria monocytogenes strains and 3 filamentous fungi; the antioxidant and pharmacological effect was also studied and the results correlated against the chemical composition. The results show that the wide variability in bioactivity between samples cannot be directly correlated with the country of origin nor the main chemical components. This suggests that the many different paramedical effects of geranium oil, which are accredited to geranium oil regardless of its chemical composition, may be due to its action as an odor through the limbic system.
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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 (Peña 1962).
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Tea tree oil, or the essential oil of Melaleuca alternifolia, is becoming increasingly popular as a naturally occurring antimicrobial agent. The antimicrobial activity of eight components of tea tree oil was evaluated using disc diffusion and broth microdilution methods. Attempts were also made to overcome methodological problems encountered with testing compounds which have limited solubility in aqueous media. After assessing media with and without solubilizing agents, the disc diffusion method was used to determine the susceptibility of a range of micro-organisms to 1,8-cineole, 1-terpinen-4-ol, ρ-cymene, linalool, α-terpinene, γ-terpinene, α-terpineol and terpinolene. While the disc diffusion method lacked reproducibility, it was considered useful as a procedure for screening for antimicrobial activity. Terpinen-4-ol was active against all the test organisms while ρ-cymene demonstrated no antimicrobial activity. Linalool and α-terpineol were active against all organisms with the exception of Pseudomonas aeruginosa. Minimum inhibitory and minimum cidal concentrations of each component against Candida albicans, Escherichia coli and Staphylococcus aureus were determined using a broth microdilution method. Modifications to this method overcame solubility and turbidity problems associated with the oil components and allowed the antimicrobial activity of each of the components to be quantified reproducibly. There was reasonable agreement between minimum inhibitory concentrations and zones of inhibition. These results may have significant implications for the future development of tea tree oil as an antimicrobial agent.
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Fifty plant essential oils were examined for their antibacterial properties against 25 genera of bacteria. Four concentrations of each oil were tested using an agar diffusion technique. The ten most inhibitory oils were thyme, cinnamon, bay, clove, almond (bitter), lovage, pimento, marjoram, angelica and nutmeg. The most comprehensively inhibitory extracts were angelica (against 25 genera), bay (24), cinnamon (23), clove (23), thyme (23), almond (bitter) (22), marjoram (22), pimento (22), geranium (21) and lovage (20).
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'Aromatherapy' is one of the most actively growing forms of alternative medicine combining massage together with counselling and a nice odour. Most clients suffer from some kind of stress-related disorder and aromatherapy encourages the healing process largely through relaxation and the relief of stress. Stress is also a major problem in hospitals, hospices and homes for the aged and physically or mentally-challenged. Aromatherapy is welcomed by nurses who want to be closer to their patient and doctors who can refer patients with stress-related disorders who do not respond to conventional medicines. The actual mode of action of essential oils in vivo is still far from known, although there is strong in vitro evidence that essential oils can act as an antimicrobial or antioxidant agent or have a pharmacological effect on various tissues. Studies have shown that essential oils have an effect on brainwaves and can also alter behaviour. It is possible that most of the effect of the oils is probably transmitted through the brain via the olfactory system. Used professionally and safely, aromatherapy can be of great benefit as an adjunct to conventional medicine or used simply as an alternative.
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The concentrations and enantiomeric purity of the major monoterpene constituents in a number of Melaleuca alternifolia (tea tree) oils have been determined by enantioselective gas chromatography. Consistent enantiomeric ratios of 65:35 (+:-) for terpinen-4-ol and 76:24 (+:-) for α-terpineol were observed for the range of oils analyzed. Attempts to validate these ratios in the intact oil by 1H NMR together with chiral lanthanide shift reagents have not yet been successful. 1H NMR was, however, successful in confirming the enantiomeric purity determined by gas chromatography of standard terpinen-4-ol [79:21 (+:-)] and α-terpineol [35:65 (+:-)] samples. Under the correct conditions, a single analysis on a β-cyclodextrin column enables the determination of the quality of the oil as set forth by the Australian standard and provides additional enantiomeric evidence of the authenticity of the oil.
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Four acyl-phloroglucinol derivatives showing antiviral activity have been isolated from Kunzea sinclairii and Kunzea ericoides (Myrtaceae) from New Zealand. The structures of these compounds were deduced from analysis of spectral data. Two of these compounds, 1 and 2, are the isomers of isobutyryl methoxyresorcinol. The two new compounds, 3 and 4, were isolated as a mixture and determined to be 4-cyclohexene-1,3-dioxo-5-hydroxy-2,2,6,6-tetramethyl-4- (1-[2,6-dihydroxy-4- methoxy-3-(3-methyl-1-oxobutyl)phenyl]-3-methylbutyl) and its 2-methyl-1-oxopropyl analogue, respectively.
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To assess the variation in antibacterial activity of honey a survey was carried out on 345 samples of unpasteurized honey obtained from commercial apiarists throughout New Zealand. Most of the honeys were considered to be monofloral, from 26 different floral sources. The honeys were tested against Staphylococcus aureus in an agar well diffusion assay, with reference to phenol as a standard. Antibacterial activity was found to range from the equivalent of less than 2% (w/v) phenol to 58% (w/v) phenol, with a median of 13.6 and a standard deviation of 12.5. Neither the age of the honey samples nor whether they had been processed by the apiarist was associated with lower activity. However, the difference between floral sources in the antibacterial activity was very highly significant. Kanuka (Kunzea ericoides (A. Rich.) J. Thompson. Family: Myrtaceae), manuka (Leptospermum scoparium J. R. et G. Forst. Family: Myrtaceae), ling heather (Calluna vulgaris (L.) Hull. Family: Ericaceae) and kamahi (Weinmannia racemosa Linn. f. Family: Cunoniaceae) were shown to be sources likely to give honey with high antibacterial activity. When antibacterial activity was assayed with catalase added to remove hydrogen peroxide, most of the honeys showed no detectable antibacterial activity. Only manuka and vipers bugloss (Echium vulgare L. Family: Boraginaceae) honeys showed this type of activity in a significant proportion of the samples. The high antibacterial activity of manuka honey was in many cases due entirely to this non-peroxide component.
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The percutaneous absorption of the fragrance diethyl maleate was measured in vivo in human and monkey studies. With the application sites occluded, 54% of the applied dose of the volatile fragrance penetrated human skin in 24 hr compared with 69% absorption in the monkey skin. It was concluded that the monkey is a good model for human skin with regard to the penetration of this fragrance material since no significant difference in the absorption of diethyl maleate was observed. The percutaneous absorption of the fragrances benzyl acetate and five other benzyl derivatives (benzyl alcohol, benzyl benzoate, benzamide, benzoin and benzophenone) was determined in vivo in monkeys. Absorption through occluded skin was high for all compounds (approximately 70% of the applied dose in 24 hr) and no significant differences between the values for the different compounds were observed. No correlations were seen between skin penetration of these compounds and their octanol-water partition coefficients. Under unoccluded conditions skin penetration of the fragrances was reduced and there was great variability between compounds, presumably because of variations in the rates of evaporation from the site of application. The data suggest that humans may have significant systemic exposure to these fragrance materials.
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Ninety-three different commercial essential oils were screened for activity against 20 Listeria monocytogenes strains in vitro and the results correlated against the actual chemical composition of each oil. There was a substantial difference in the activity between different essential oils as expected, but there was also a difference in activity between different samples of the same essential oil. Strong anti-Listeria activity was often correlated with essential oils containing a high percentage of monoterpenes, eugenol, cinnamaldehyde, thymol, and sometimes with citronellol, limonene and geraniol. However, as there was often no correlation between the anti-Listeria activity and the main chemical components, it is possible that either there is a more complex relationship with the chemical composition (which includes the minor components) or that substantial adulteration had occurred in some essential oil samples.
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The two New Zealand tea-tree oils, Manuka (Leptospermum scoparium J.R. et G. Forst) and Kanuka (Kunzea ericoides (A. Rich) J. Thompson), Myrtaceae have been used as folk medicines for treating diarrhoea, colds and inflammation but their pharmacological action has not been investigated. Their mode of action was therefore studied on the field-stimulated guinea-pig ileum. Both Manuka and Kanuka oils induced a spasmolytic effect but Kanuka produced an initial contraction. The spasmolytic action of both oils was the result of a post-synaptic mechanism. Action involving adrenoceptors or cGMP was not considered likely, neither did the oils behave like calcium- or potassium-channel openers. There is some evidence that Manuka acts through cAMP whereas the mode of action of Kanuka is as yet undetermined. The results indicate that the use of these oils as relaxants in aromatherapy might be valid, although their mode of action is not identical.