Eucalyptus Globulus Essential Oil Research Articles

<i>Eucalyptus globulus</i> Oil Versus Bleach Use as Antiseptic Agents in Podoconiosis Treatment: An Interventional Study in Wolaita Zone, Southern Ethiopia

Eucalyptus globulus essential oil is widely used for medicinal purpose because of its pharmacological constituents. The present study aimed to use water emulsified E. globulus oil as an antiseptic agent in the treatment protocol of podoconiosis (non-filarial elephantiasis) and compare disease improvement upon E. globulus oil versus bleach (usual antiseptic chemical) use in the treatment protocol. An interventional study was conducted from January to March, 2012 to compare disease improvement on podoconiosis upon using water emulsified E. globulus oil versus bleach-water solution as antiseptic agents in podoconiosis treatment. Forty podoconiosis patients purposely selected and randomly allocated into intervention (E. globulus oil) group and comparison (bleach) group with matched clinical stage of podoconiosis. After the baseline data recording, home based treatment was started and follow-up had been undertaken every week for 3-month period. The data were analyzed using SPSS version 16 statistical package. The mean clinical stages of the disease among the study participants were 2.72 for the right and 2.80 for the left legs before the treatment start. Seventeen (32.5%) of patients suffered from the disease for more than 25 years. For all the outcomes measured at the end of study period, the individual treatment effects of eucalyptus oil and bleach antiseptic agents were compared and the result showed no significant difference. Hence, eucalyptus oil emulsified in water can be used as alternative antiseptic agent in podoconiosis treatment protocol.

Extraction and Antibacterial Activity of Essential Oils from Eucalyptus globulus

The essential oil of Eucalyptus globulus obtained by hydrodistillation (Fever tree) was investigated for activity against two bacteria (Staphylococcus aureus and Klebsiella pneumoniae). The oil was extracted using a Clevenger-type apparatus. Separation, identification and determination of percentage composition of compounds present in the oil were carried out by Gas Chromatography Mass Spectrometry. The antibacterial activity was investigated by agar diffusion technique using various concentrations of the essential oil: 100% v/v, 75% v/v, 50% v/v, 25% v/v, 15% v/v. Minimum inhibitory concentration was determined using turbidimetric assay by taking the absorbance with the aid of a spectrophotometer. Minimum bactericidal concentration was by plate assay. Gas Chromatography Mass Spectrometry revealed the presence of seven compounds, all amounting to 90.4% with globulol having the highest percentage composition of 30.1%. The evaluation of sensitivity of the oil revealed the highest activity at 100% v/v against both isolates. Minimum inhibitory concentration was obtained at 25% v/v when assayed against K. pneumoniae with no activity at all against S. aureus at the same concentration. Oil showed no bactericidal activity at all concentrations, suggesting only bacteristatic activity of the oil. Investigation from this work revealed that the essential oil of E. globulus exhibit activity against the tested isolates and can thus be employed in the treatment of infections caused by them.

Antimicrobial activity of essential oil of Eucalyptus globulus against fish pathogenic bacteria.

The antibacterial activities of the essential oil of Eucalyptus globulus (EOEG) was determined against 7 fish pathogenic bacteria (Edwardsiella tarda, Streptococcus iniae, S. parauberis, Lactococcus garviae, Vibrio harveyi, V. ichthyoenteri and Photobacterium damselae) obtained from farmed olive flounder. The inhibitory activity was evaluated by three methods: Disc diffusion method, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). According to the disc diffusion test, as the concentration of EOEG (5-40 µg) rises, the inhibitory zone increases in size. Compared with amoxicillin, tetracycline and chloramphenicol, EOEG showed similar antibacterial activity. The MIC of EOEG ranged from 7.8 to 125 mg/mL and MBC values ranged from 62 to 250 mg/mL. These results show that EOEG has antimicrobial activity against all seven bacteria, but there was no marked difference between each genus. From these results, it is suggested that EOEG can be used as an antimicrobial agent against fish bacterial diseases in the fish industry.

Physical, antioxidant and antimicrobial properties of chitosan films containing Eucalyptus globulus essential oil

Abstract In this work active films from chitosan containing Eucalyptus globulus (EG) essential oil (0, 1, 2, 3 and 4% (v/v)) were developed by casting and solvent-evaporation method. Then, the physical properties, the total phenolic content, the antioxidant and antimicrobial activities of different films were assessed, to define if the chitosan films incorporated with EG essential oil could be used as natural active films for food use. The antioxidant activity was determined with three different analytical assays (DPPH, NO and H2O2). The agar disc diffusion method was used to determine the antimicrobial activity against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans and Candida parapsilosis. In fact, incorporating EG essential oil into chitosan-based films significantly decreases moisture content and water-solubility. These results can be explained by the films microstructure, which was analyzed by scanning electron microscopy. The antioxidant properties proved to be significantly enhanced with increasing EG essential oil concentration. The microbiological assessment confirmed antimicrobial efficiency of chitosan films EG containing essential oil. The mentioned results proved the potential of this original material which could be used as active films due to its excellent antimicrobial and antioxidant activities.

Chemical composition, antibacterial and antioxidant activities of essential oil of Eucalyptus globulus from Algeria

Essential oils are known for their use in various fields such as cosmetic, pharmaceutical and food industries. The aim of this work is to investigate the chemical composition of essential oils from Eucalyptus globulus leaves (E. globulus) by gas-chromatography coupled with mass spectrometry (GC/MS) method, and to evaluate their antioxidant capacity (DPPH radical scavenging effect, reducing power, and inhibition of lipid peroxidation activity) as well as their antibacterial activity, against periodontopathogenic and cariogenic bacterial species, using microdilution method in 96-well microplates. In total, 26 compounds were identified with the predominance of oxygenated monoterpenes (78.58%); 1,8-Cineole (55.29%), Spathulenol (7.44%) and α-Terpineol (5.46%) being the main components. The analyzed oils exhibited a weak antioxidant capacity, but a marked antibacterial activity against Gram negative bacteria, mainly for F. nucleatum ATCC 25586 (MIC=1.14mg/mL) and P. gingivalis ATCC33277 (MIC=0.28mg/mL). Therefore, E. globulus essential oils may have a potential therapeutic application for the treatment of periodontal diseases.

Antimicrobial activity of Eucalyptus globulus oil, xylitol and papain: a pilot study

To evaluate the in vitro antimicrobial activity of the Eucalyptus globulus essential oil, and of the xylitol and papain substances against the following microorganisms: Pseudomonas aeruginosa; Samonella sp.; Staphylococus aureus; Proteus vulgaris; Escherichia coli and Candida albicans. The in vitro antimicrobial evaluation was used by means of the agar diffusion test and evaluation of the inhibition zone diameter of the tested substances. Chlorhexidine 0.5% was used as control. The Eucalyptus globulus oil showed higher inhibition than chlorhexidine when applied to Staphylococcus aureus, and equal inhibition when applied to the following microorganisms: Escherichia coli, Proteus vulgaris and Candida albicans. Papain 10% showed lower antimicrobial effect than chlorhexidine in relation to Candida albicans. Xylitol showed no inhibition of the tested microorganisms. The Eucalyptus globulus oil has antimicrobial activity against different microorganisms and appears to be a viable alternative as germicidal agent hence, further investigation is recommended.

Strategic control of postharvest decay in peach caused byMonilinia fructicolaandColletotrichum gloeosporioides

In this work we report the postharvest control of Monilinia fructicola - causative agents of brown rot and Colletotrichum gloesporioides - causative agents of anthracnose. These fungi contribute significantly to the reduction of the marketing period of peach. The conventional control of these diseases can leave chemical residues on fruits and selecting resistant pathogenic strains. The use of essential oils can be a more appropriate alternative. Essential oil of Eucalyptus globulus, Cinnamomum camphora and Cymbopogum citratus were used in control. The results have demonstrated good control of these diseases manly using C. camphora and C. citratus in vitro and in vivo analysis beyond in vivo simulating cold storage. Our results in these essays indicate the possibility of using environmental-friendly essential oil in postharvest control of peaches and others fruits, without utilization of chemical fungicides.

Quality Assessment of the Essential Oil from <i>Eucalyptus globulus</i> Labill of Blida (Algeria) Origin

Despite the reputation earned by aromatic and medicinal plants of Algeria, the chemical constituents of Eucalyptus globulus essential oil (EGEO) of Blida origin has not previously been investigated. Thus, the present study has been conducted for the determination of chemical constituents and different physico-chemical properties of the EGEO. Chemical composition of the EGEO, grown in Algeria, was analysed by Gas Chromatography-Mass Spectrometry. The chemical components were identified on the basis of Retention Time and comparing with mass spectral database of standard compounds. Relative amounts of detected compounds were calculated on the basis of GC peak areas. Fresh leaves of E. globulus on steam distillation yielded 0.96 % (v/w) of essential oil whereas the analysis resulted in the identification of a total of 11 constituents, 1.8 cineole (85.8 %), α-pinene (7.2 %), and β-myrcene (1.5 %) being the main components. Other notable compounds identified in the oil were β-pinene, limonene, α-phellandrene, γ-terpinene, linalool, pinocarveol, terpinen-4-ol, and α-terpineol. The physical properties such as specific gravity, refractive index and optical rotation and the chemical properties such as saponification value, acid number and iodine number of the EGEO were examined. The oil extracted has been analyzed to have 1.4602 - 1.4623 refractive index value, 0.918 - 0.919 specific gravity (sp.gr.), +9 - +10 optical rotation that satisfy the standards stipulated by European Pharmacopeia. All the physical and chemical parameters were in the range indicated by the ISO standards. Our findings will help to access the quality of the Eucalyptus oil which is important in the production of high value essential oils that will help to improve the economic condition of the community as well as the nation.

Quality Assessment of the Essential Oil from <i>Eucalyptus globulus</i> Labill of Blida (Algeria) Origin

Despite the reputation earned by aromatic and medicinal plants of Algeria, the chemical constituents of Eucalyptus globulus essential oil (EGEO) of Blida origin has not previously been investigated. Thus, the present study has been conducted for the determination of chemical constituents and different physico-chemical properties of the EGEO. Chemical composition of the EGEO, grown in Algeria, was analysed by Gas Chromatography-Mass Spectrometry. The chemical components were identified on the basis of Retention Time and comparing with mass spectral database of standard compounds. Relative amounts of detected compounds were calculated on the basis of GC peak areas. Fresh leaves of E. globulus on steam distillation yielded 0.96 % (v/w) of essential oil whereas the analysis resulted in the identification of a total of 11 constituents, 1.8 cineole (85.8 %), α-pinene (7.2 %), and β-myrcene (1.5 %) being the main components. Other notable compounds identified in the oil were β-pinene, limonene, α-phellandrene, γ-terpinene, linalool, pinocarveol, terpinen-4-ol, and α-terpineol. The physical properties such as specific gravity, refractive index and optical rotation and the chemical properties such as saponification value, acid number and iodine number of the EGEO were examined. The oil extracted has been analyzed to have 1.4602 - 1.4623 refractive index value, 0.918 - 0.919 specific gravity (sp.gr.), +9 - +10 optical rotation that satisfy the standards stipulated by European Pharmacopeia. All the physical and chemical parameters were in the range indicated by the ISO standards. Our findings will help to access the quality of the Eucalyptus oil which is important in the production of high value essential oils that will help to improve the economic condition of the community as well as the nation.

Potential use of Eucalyptus globulus essential oil against Phytophthora colocasiae the causal agent of taro leaf blight

This study was carried out to determine the antimicrobial activity of essential oil derived from leaves of eucalyptus (Eucalyptus globulus) against Phytophthora colocasiae, the causal agent of taro leaf blight (TLB). Essential oil was obtained by Clevenger-type water distillation. The major compounds in this essential oil were identified using gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC/MS). Antimicrobial activity of the essential oil was tested in vitro against mycelial growth, sporangia and zoospores germination of P. colocasiae. Additionally, in situ tests were conducted on detached healthy taro leaves discs and evaluating necrosis symptoms of TLB were assessed. Results of the chemical composition of the essential oil analysis showed that, 1.8-cineole (26.4 %), α-pinene (14.1 %) and p-cymene (10.2 %) are the most abundant compounds. In addition, four components could be identified in noticeable amounts (18.1 % in the total): regulator G1/G2 and its derivatives as well as flavesone, a regulator G3 derivative. G is a generic term for a family of 2,3-dioxabicyclo[4,4,0] decane system growth regulators. Here, G-regulators and derivatives are described for the first time in E. globulus. Antimicrobial activity of the essential oil was recorded with total inhibition of mycelia growth and sporangia germination at 0.625 mg/ml, while the complete inhibition of zoospores germination was recorded at 0.156 mg/ml. In situ results showed that essential oil completely inhibited the appearance of disease symptoms, necrosis development and sporulation at 3.5 mg/ml. These results demonstrated that, the essential oil of Eucalyptus globulus has high ability to inhibit the development of P. colocasiae, and might be used for controlling TLB.

In vitro activity of Melaleuca alternifolia (Tea tree) and Eucalyptus globulus essential oils on oral Candida biofilm formation on polymethylmethacrylate

Melaleuca alternifolia and Eucalyptus globulus essential oils are known for their antifungal activities and efficacy in the treatment of oral candidiasis. Candida biofilm increased resistance to antifungal agents that have activity against their planktonic cells. The aim of this study was to evaluate the potential role of M. alternifolia and E. globulus essential oils in the inhibition of Candida biofilm formation on polymethylmethacrylate (PMMA). The antifungal activity of M. alternifolia and E. globulus essential oils and adhesion and biofilm on PMMA inhibition capacity were tested on two oral Candida isolates and two reference type strains. The biofilm formation by Candida strains was quantified by colorimetric method based on the reduction of the 2, 3-bis (2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenyl amino) carbonyl]-2H-tetrazolium hydroxide (XTT). M. alternifolia and E. globulus essential oils were active against clinical and reference Candida albicans and Candida glabratastrains in their planktonic and adherent phases. In fact, both minimum inhibition concentration (MIC) and 1/2 MIC values of these two plants essential oils can inhibit adhesion and biofilm formation of clinical and reference strains of Candida on PMMA. Also,E. globulus essential oil was more active on Candida biofilm formation on PMMA. M. alternifolia and E. globulus essential oils can inhibit Candida biofilm formation on PMMA. This may contribute to the use of these plants as alternative products for oral Candidabiofilm prevention, control and treatment. Key words: Candida, biofilm, polymethylmethacrylate, Melaleuca alternifolia, Eucalyptus globulus.

Compositional analysis and insecticidal activity of Eucalyptus globulus (family: Myrtaceae) essential oil against housefly (Musca domestica)

The essential oil of Eucalyptus globulus (Myrtales: Myrtaceae) was evaluated for its chemical composition and insecticidal activity against the housefly, Musca domestica L. (Diptera: Muscidae). Chemical composition of E. globulus oil revealed 1,8-cineole (33.6%), α-pinene (14.2%) and d-limonene (10.1%) as major constituents, while vapour profile of E. globulus oil determined through solid phase microextraction (SPME) analysis showed 1,8-cineole (56.5%), α-pinene (16.9%), d-limonene (5.5%) and linalool acetate (3.4%) as principal components. Vapour phase of the oil showed increase in the contents of oxygenated monoterpenes. Insecticidal activity of E. globulus oil was assessed against larvae and pupae of housefly, through two different bioassays: contact toxicity and fumigation. Contact toxicity assay with larva showed lethal concentration, LC50, between 2.73 and 0.60μl/cm2 for different observation days while lethal time, LT50, varied between 6.0 and 1.7 days. In fumigant assay for housefly larvae, LC50 values of 66.1 and 50.1μl/l were obtained in 24h and 48h, respectively. Oil treated larvae showed surface shrinkage, spinous cells proliferation and bleb formation in scanning electron microscopy (SEM) observation. Pupicidal effectivity was measured in terms of percentage inhibition rate (PIR) which was 36.0–93.0% for contact toxicity and 67.9–100% for fumigation toxicity assay. Considerable activity of E. globulus oil against larvae and pupae of housefly demonstrates its potentiality as a viable option for the development of eco-friendly product for housefly control.

Chemical composition, antioxidant and antifungal potential of Melaleuca alternifolia (tea tree) and Eucalyptus globulus essential oils against oralCandida species

Eucalyptus globulus and Melaleuca alternifolia essential oils has been of interest to researchers because they are traditionally used for the treatment of fungal infections and especially candidiasis. The chemical composition of hydrodistilled essential oils were analyzed by gas chromatography-mass spectrometry (GC-MS), and their antifungal activity was tested against 32 Candida strains including 15 species. The antioxidant activities (DPPH, reducing power, and superoxide anion radical-scavenging activity) were also investigated. Tea tree essential oil was particularly rich on terpinen-4-ol (40.44%), gamma terpinene (19.54%) and 1,8-cineole (95.61%) and alpha-pinene (1.5%) for the E. globulus oil. E. globulus oil was more efficient and had the best antifungal effect on oral Candida albicans and Candida glabratastrains comparing to the results obtained with Amphotericin B. Even at low concentrations, these oils drastically impair the maximum yield and growth rate of both C. albicans and C. glabrata on YPD medium. The Tea Tree essential oil displayed the highest DPPH scavenging ability with the lowest IC50 value (IC50, 12.5 µg/ml), the greater reducing power and bleaching of β-carotene (EC50, 24 µgml-1 and IC50, 42 µgml-1, respectively) as compared to E. globulusoil and BHT. These findings support the interest of E. globulus and M. alternifolia essential oilsas an efficient oral hygiene tool (anti-Candida spp.) and as a source of antioxidant compounds. Key words: Candida, Melaleuca alternifolia, Eucalyptus globulus, gas chromatography-mass spectrometry, antioxidant, antifungal activities.

Chemical composition and antimicrobial activity of essential oils of Thymus algeriensis, Eucalyptus globulus and Rosmarinus officinalis from Morocco

The present study reports on the antimicrobial activity and chemical composition of the essential oils (EOs) of Thymus algeriensis, Eucalyptus globulus and Rosmarinus officinalis from Morocco. The composition of these species was analysed by GC-MS, and 65 components were identified. Eucalyptus globulus EO showed a great similarity with EOs from other regions, with 1,8-cineole (79.85%) the major component. Also rich in this constituent was Rosmarinus officinalis (43.99%). However, the chemical profile of Thymus algeriensis was rather different, and for the first time such a high content of borneol (23.48%) has been described in this EO. The antimicrobial activity of these species has also been studied against seven pathogenic and spoiling bacteria of significant importance. According to the results, Thymus algeriensis showed the best bacteriostatic and bactericidal effect, followed by Eucalyptus globulus and Rosmarinus officinalis. As far as we know this is the first time that minimum inhibitory and bactericidal concentration values have been reported for Eucalyptus globulus EO. Our data support the possible use of this EO as well as Thymus algeriensis EO, as potential natural agents in preservatives for food and pharmaceutical products.

Antimicrobial effect of essential oil isolated from Eucalyptus globulus Labill. from Montenegro

Chemical composition of the essential oil of Eucalyptus globulus Labill., grown in Montenegro, was analysed by gas chromatography-mass spectrometry and its antimicrobial activity was evaluated against 17 microorganisms, including food poisoning and spoilage bacteria and human pathogens.The Eucalyptus essential oil yield was 1.8% (w/w) on the fresh weight basis, whereas the analysis resulted in the identification of a total of 11 constituents, 1.8 cineole (85.8%), α-pinene (7.2%), and β-myrcene (1.5%) being the main components. Other compounds identified in the oil were<br />β-pinene, limonene, α-phellandrene, γ-terpinene, linalool, pinocarveol, terpinen-4-ol, and α-terpineol. The results of the antimicrobial activity tests revealed that the essential oil of E. globulus has rather a strong antimicrobial activity, especially against Streptococcus pyogenes, Escherichia coli, Candida albicans, Staphylococcus aureus, Acinetobacter baumannii, and Klebsiella pneumoniae. Minimum inhibitory concentration revealed the lowest activity against Pseudomonas aeruginosa and Salmonela infantis (3.13 mg/ml) while the highest activity was against S. aureus, E. coli, and S. pyogenes (0.09 mg/ml).

Antimicrobial potential and chemical composition of Eucalyptusglobulus oil in liquid and vapour phase against food spoilage microorganisms

The antimicrobial activity of Eucalyptusglobulus essential oil was evaluated against 14 food spoilage microorganisms in liquid and vapour phase using agar dilution/well diffusion method and disc volatilisation method, respectively. The minimum inhibitory concentration (MIC) varied from 2.25 to 9mg/ml for bacterial and fungal strains, and from 1.13 to 2.25mg/ml for yeast strains. Significantly higher antimicrobial activity was observed in the vapour phase. The chemical composition of E. globulus in liquid as well as in the vapour phase was determined by gas chromatography (GC), gas chromatography/mass spectrometry (GC-MS) and solid phase micro extraction-gas chromatography mass spectrometry (SPME GC-MS), respectively. The dominant compounds in E. globulus oil were 1,8-cineole (45.4%), limonene (17.8%), p-cymene (9.5%), γ-terpinene (8.8%), α-pinene (4.2%) and α-terpineol (3.4%), while in the vapour, 1,8-cineole (34.6%), limonene (29.9%), p-cymene (10.5%), γ-terpinene (7.4%), α-pinene (4.0%) and α-phellandrene (2.4%) were identified.

Antimicrobial and miticide activities of Eucalyptus globulus essential oils obtained from different Argentine regions

The biological activity of Eucalyptus globulus essential oils derived from plant material obtained from different geographic areas was analyzed in in vitro experiments on Paenibacillus larvae, Varroa destructor, and Apis mellifera. The physicochemical properties, composition, antimicrobial, and bioactivity of these essential oils were studied. The bioactivity against P. larvae was analyzed by means of two in vitro techniques (tube dilution and bioautography). Mite and bee lethality were estimated using a complete exposure method test with oils at different concentrations. Essential oils differed in their composition, albeit their similar physicochemical properties. The minimal inhibitory concentrations range for E. globulus essential oil lay between 600-700 µg mL–1 for Mar del Plata and 900-1,200 µg mL–1 for Valle de Conlara essential oils against all P. larvae strains. The bioautography method determined that limonene accounted for the greatest antimicrobial activity with respect to the other compounds. The complete exposure method at 24, 48, and 72 h yielded lower LC50 values for mites exposed to E. globulus essential oils from Conlara. LC50 values for acari after 72 h of treatment with E. globulus from Mar del Plata and Conlara were 47.1 and 11.7 µL capsule–1, respectively; whilst those for bees was > 20 µL capsule–1 for both oils. The E. globulus essential oils tested in this study featured high efficiency against V. destructor, yet their antimicrobial activity against P. larvae proved to be lower, and innocuous to bees. The present experience promotes the use of active compounds for American fouldbrood and Varroosis management.

Synergistic properties of the terpenoids aromadendrene and 1,8-cineole from the essential oil of Eucalyptus globulus against antibiotic-susceptible and antibiotic-resistant pathogens

The aim of the present study was to investigate the chemical composition of the essential oil of the fruits of Eucalyptus globulus and to examine the potential application of the fruit oil against multidrug-resistant bacteria. GLC/MS analysis in the fruit oil showed that aromadendrene was the main compound followed by 1,8-cineole and globulol. The three most abundant components of the fruit oil were also tested individually against microorganisms. In addition, the synergistic effects of combinations of the major constituents (aromadendrene and 1,8-cineole) of the fruit oil were also investigated. All Gram-positive bacteria were susceptible to the fruit oil with different degrees of susceptibility as determined by microdilution method. The oil exerted a marked inhibition against multidrug-resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) Enterococcus faecalis. The results indicated that aromadendrene might be responsible for the antimicrobial properties, whereas 1,8-cineole and globulol exhibited low activities. The checkerboard assay demonstrated that combinations of 1,8-cineole and aromadendrene reduce the MIC in most cases in an additive way, whereas the time-kill assay indicates a synergistic effect.

In vitro effect of Melaleuca alternifolia and Eucalyptus globulus essential oils on mycelia formation by oral Candida albicans strains

Several mechanisms can inhibit mycelium formation which is an essential step forCandida albicans virulence. In this study, two essential oils of Melaleuca alternifoliaand Eucalyptus globulus were tested for their ability to inhibit the mycelium formed on Lee medium by oral C. albicans. Lee medium was added with different concentrations of M. alternifolia essential oil ranging from 0.156 to 10 mg/ml and from 0.039 to 10 mg/ml for E. globulus. The results obtained showed that 5/17 of C.albicans strains were strongly mycelium producers, nine strains were moderately mycelium producers and three isolates were unable to form hyphae after 2 h of incubation in the same medium. M. alternifolia essential oil has an antimycelial activity against C. albicans isolates than E. globulus essential oil. In fact, only 1/2 minimum inhibitory concentration (MIC) (0.312 mg/ml) of M. alternifolia was able to inhibit total mycelium in C. albicans isolate while 2 MIC (0.312 mg/ml) of the second essential oil was necessary to inhibit germ tube formation in the same strain. Key words: Candida albicans, Melaleuca alternifolia, Eucalyptus globulus, mycelium, lee medium.

Genotoxic activity of Eucalyptus globulus essential oil in Aspergillus nidulans diploid cells

Eucalyptus globulus essential oil was evaluated for its genotoxic potential using a somatic segregation assay and a diploid strain of the fungus Aspergillus nidulans, heterozygous for nutritional and conidia color markers. The main compounds of the current essential oil sample were eucalyptol (49.0 %), alpha-pinene (8.9), beta-pinene (1.5), globulol (6.9), alpha-eudesmol (1.12), spathulenol (1.42), gamma-cadinene (1.45), trans-beta-elemenone (1.23) and aromandendrene (2.3), totaling 74 % of oil. Oil at 0.12 and 0.25 microL/mL was found to increase the mitotic instability of the original diploid strain and the number of diploid mitotic recombinants of A. nidulans. The genotoxicity of the oil was associated with the induction of mitotic crossing-over or with oil-broken chromosomes.