Antimicrobial activity of clove and rosemary essential oils alone and in combination

In the present study, the antimicrobial activity of the essential oils from clove (Syzygium aromaticum (L.) Merr. et Perry) and rosemary (Rosmarinus officinalis L.) was tested alone and in combination. The compositions of the oils were analysed by GC/MS. Minimum inhibitory concentrations (MIC) against three Gram-positive bacteria, three Gram-negative bacteria and two fungi were determined for the essential oils and their mixtures. Furthermore, time-kill dynamic processes of clove and rosemary essential oils against Staphylococcus epidermidis, Escherichia coli and Candida albicans were tested. Both essential oils possessed significant antimicrobial effects against all microorganisms tested. The MICs of clove oil ranged from 0.062% to 0.500% (v/v), while the MICs of rosemary oil ranged from 0.125% to 1.000% (v/v). The antimicrobial activity of combinations of the two essential oils indicated their additive, synergistic or antagonistic effects against individual microorganism tests. The time-kill curves of clove and rosemary essential oils towards three strains showed clearly bactericidal and fungicidal processes of (1)/(2) x MIC, MIC, MBC and 2 x MIC.     

The chemical composition and biological activity of clove essential oil, Eugenia caryophyllata (Syzigium aromaticum L. Myrtaceae): a short review

The essential oil extracted from the dried flower buds of clove, Eugenia caryophyllata L. Merr. & Perry (Myrtaceae), is used as a topical application to relieve pain and to promote healing and also finds use in the fragrance and flavouring industries. The main constituents of the essential oil are phenylpropanoids such as carvacrol, thymol, eugenol and cinnamaldehyde. The biological activity of Eugenia caryophyllata has been investigated on several microorganisms and parasites, including pathogenic bacteria, Herpes simplex and hepatitis C viruses. In addition to its antimicrobial, antioxidant, antifungal and antiviral activity, clove essential oil possesses antiinflammatory, cytotoxic, insect repellent and anaesthetic properties. This short review addresses the chemical composition and biological effects of clove essential oil, and includes new results from GC/MS analysis and a study of its antimicrobial activity against a large number of multi-resistant Staphylococcus epidermidis isolated from dialysis biomaterials.     

Activity of essential oils of three Micromeria species (Lamiaceae) against micromycetes and bacteria

The chemical composition of essential oils from three Micromeria species: M. dalmatica Benth., M. albanica (Griceb. ex K. Mal) ?ili? and M. thymifolia (Scop.) Fritsch were investigated by GC and GC‐MS and their antibacterial and antifungal activities against seven fungal and six bacterial species were evaluated. Biological assays showed strong fungitoxicity of oils from all three Micromeria spp., particularly M. albanica, against all fungi tested. Essential oils of these species also exerted antibacterial effect against Streptococcus aureus, Escherichia coli, Bacillus subtilis and Micrococcus luteus at low concentrations. Higher concentrations of essential oil of M. albanica and M. dalmatica were active against Gram‐negative Pseudomonas aeruginosa, which could be due to the high content of piperitenone oxide. Copyright © 2002 John Wiley & Sons, Ltd.     

Insecticidal activity of essential oils on Triatoma infestans

Sixty-three essential oils isolated from Bolivian plants were tested on Triatoma infestans for ovicidal and larvicidal properties. Three types of test were used: topical application on insects, nymphs on impregnated paper and eggs on impregnated paper. Twenty oils showed an interesting activity on nymphs and eggs when the impregnated paper tests were used. These tests proved to be the most sensitive and were therefore chosen for studying the action of a dozen terpenes present in those active essential oils. © 1997 John Wiley & Sons, Ltd.     

The chemical composition of some Lauraceae essential oils and their antifungal activities

The antifungal activity of Aniba rosaeodora, Laurus nobilis, Sassafras albidum and Cinnamomum zeylanicum essential oils were investigated against 17 micromycetes. Among the tested fungal species were food poisoning, spoilage fungi, plant and animal pathogens. In order to determine fungistatic and fungicidal concentrations (MIC and MFC) macrodilution and microdilution tests were used. Linalool was the main component in the essential oil of A. rosaeodora, while 1.8-cineole was dominant in L. nobilis. In sassafras essential oil safrole was the major component and in the oil of C. zeylanicum the main component was trans-cinnamaldehyde. The essential oil of cinnamon showed the strongest antifungal activity.     

Insecticidal activity of essential oils on Aedes aegypti larvae

The insecticidal activity of essential oils from 52 Bolivian plant species has been evaluated on Aedes aegypti larvae. The active components of essential oils showing an interesting larvicidal effect have been studied. The monoterpenes E-anethol and E-nerolidol were found to be the active principles of the most toxic essential oils. The lethal concentrations (LC₅₀ and LC₉₅) of some essential oils, E-anethol, E-nerolidol and a reference insecticide (Temephos) are given. © 1998 John Wiley & Sons, Ltd.     

Chemical composition and antimicrobial activity of the essential oils of different samples of Thymus baeticus boiss

Gas chromatography was used to determine the chemical composition of the essential oil of female and hermaphrodite Thymus baeticus Boiss. collected in Ugijar (province of Granada, Spain). The results were compared with the chemical composition of other samples of the same species, collected in Lanjarón. These comparisons showed some qualitative differences, and more obvious quantitative differences, in the compositions of the essential oils. We also investigated the antimicrobial activity of all samples. This activity, although marked in all samples, was greater in essential oils containing larger amounts of geraniol.     

The antimicrobial activity of essential oils of Hypericum scabrum, Hypericum scabroides and Hypericum triquetrifolium

The essential oils of Hypericum scabrum, Hypericum scabroides and Hypericum triquetrifolium were studied for the first time for their antimicrobial activity against nine organisms. All the essential oils exhibited some broad spectrum antibacterial activity, at a concentration of 80 microg/mL. The essential oils of Hypericum species showed antibacterial activity against the tested organisms and a yeast.     

柱果绿绒蒿挥发油化学成分及其抗氧化活性的研究

目的:分析柱果绿绒蒿挥发油的化学成分并进行抗氧化活性研究.方法:采用水蒸气蒸馏法获得挥发油,运用气相色谱-质谱联用进行成分分析,同时运用紫外分光光度计测定其对羟基自由基的清除能力,用酶标仪测定其对1,1-二苯基-2-三硝基苯肼(DPPH)自由基的清除能力,并与2,6--二叔丁基-4-甲基苯酚(BHT)比较.结果:从柱果绿绒蒿的挥发油中鉴定了47个化合物,占其总量的91.866％;挥发油对羟基自由基和DPPH自由基的清除能力均强于BHT.结论:柱果绿绒蒿挥发油的化学成分复杂,主要为十六烷酸(27.653％)和6,10,14-三甲基-2-十五烷酮(16.330％);其清除自由基的能力显示出良好的抗氧化活性.     

Phytochemical analysis and in vitro antimicrobial activity of two Satureja species essential oils

The phytochemical GC[sol ]MS analysis and in vitro antimicrobial activity of the essential oils of the aerial parts of Satureja montana L. and Satureja cuneifolia Ten., collected in Croatia were performed. The major compound of S. montana oil was the phenolic monoterpene carvacrol (45.7%). Other important compounds were the monoterpenic hydrocarbons p-cymene (12.6%), gamma-terpinene (8.1%) and the oxygen-containing compounds carvacrol methyl ether, borneol, thymol and thymol methyl ether. The volatile oil of S. cuneifolia was characterized as beta-cubebene (8.7%), limonene (8.3%), alpha-pinene (6.9%), spathulenol and beta-caryophyllene. The antimicrobial effects of S. montana and S. cuneifolia oils were found to have a broad spectrum activity against multidrug-resistant pathogens by the broth microdilution method. These oils were active against all the test strains, with the exception of Pseudomonas aeruginosa. Compared with S. cuneifolia, savory oil exhibited greater antimicrobial activity. The maximum activity of savory oil was observed against Escherichia coli, methicillin-resistant Staphylococcus aureus and against the yeast (Candida albicans). The essential oil of S. cuneifolia was also found to inhibit the growth of medically important pathogens such as S. aureus and E. coli. Fungicidal activity for both oils against C. albicans and S. cerevisiae was also observed.     

Activity of essential oils from Brazilian medicinal plants on Escherichia coli

Essential oils obtained from leaves of 29 medicinal plants commonly used in Brazil were screened against 13 different Escherichia coli serotypes. The oils were obtained by water-distillation using a Clevenger-type system and their minimal inhibitory concentration (MIC) were determined by microdilution method. Essential oil from Cymbopogon martinii exhibited a broad inhibition spectrum, presenting strong activity (MIC between 100 and 500 microg/mL) against 10 out of 13 Escherichia coli serotypes: three enterotoxigenic, two enteropathogenic, three enteroinvasive and two shiga-toxin producers. C. winterianus inhibited strongly two enterotoxigenic, one enteropathogenic, one enteroinvasive and one shiga-toxin producer serotypes. Aloysia triphylla also shows good potential to kill Escherichia coli with moderate to strong inhibition. Other essential oils showed antimicrobial properties, however with a more restricted action against the serotypes studied. Chemical analysis of Cymbopogon martinii essential oil performed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC-MS) showed the presence of compounds with known antimicrobial activity, including geraniol, geranyl acetate and trans-cariophyllene, which tested separately, indicated geraniol as antimicrobial active compound. The significant antibacterial activity of Cymbopogon martinii oil suggests that they could serve as a source for compounds with therapeutic potential.     

超临界CO2萃取苗药大果木姜子果实挥发油化学成分研究

目的研究苗药大果姜子果实挥发油的化学成分并初步探讨其抗心血管活性成分。方法采用了超临界CO_2萃取方法从大果木姜子果实中提取挥发油,运用气相色谱-质谱-计算机联用技术对其化学成分进行鉴定,用面积归一化法测定各化合物在果实挥发油中的相对百分含量。结果共分离鉴定了58个化学成分,占总挥发油成分的51.95%。结论主要成分是古巴烯7.73%、n-癸酸4.68%、桉树脑3.24%、斯巴醇3.20%、β-人参萜烯3.11%,为进一步开发大果木姜子提供科学依据。     

Chemical and biological evaluation of the essential oils of different Melaleuca species

The essential oils of the fresh leaves of M. ericifolia, M. leucadendron, M. armillaris and M. styphelioides were isolated by a hydrodistillation method and analysed by a gas chromatography/mass spectrometry (GC/MS) technique. The essential oil of M. ericifolia contained methyl eugenol (96.84%) as a major constituent, whereas M. leucadendron was rich in 1,8-cineole (64.30%). The essential oil of M. armillaris was rich in 1,8-cineole (33.93%) followed by terpinen-4-ol (18.79%), whereas M. styphelioides was rich in caryophyllene oxide (43.78%) and (-) spathulenol (9.65%). The essential oils of these species possessed antimicrobial and antifungal activities. M. ericifolia exhibited the highest inhibitory effects against Bacillus subtiles and Aspergillus niger. The antiviral activities of the essential oils against Herpes simplex virus type 1 (HSV-1) were studied in African green monkey kidney cells (Vero) by a plaque reduction assay. The volatile oil of M. armillaris was more effective as a virucidal (up to 99%) than that of M. leucadendron (92%) and M. ericifolia (91.5%). The effects of the essential oils on the antioxidant system status in carbon tetrachloride treated animals were studied. The essential oil of M. armillaris exhibited a marked antioxidant effect, it improved vitamin E, vitamin C and superoxide dismutase parameters so it can be used as a free radical suppressor.     

In vitro antimicrobial efficacy of leaf essential oils of Chukrasia tabularis Adr Juss and Melia dubia Cav (Meliaceae)

The essential oils of Chukrasia tabularis and Melia dubia were tested for their antimicrobial activity against ten different pathogenic microorganisms responsible for human pathologies using standard antimicrobial assays. Chukrasia tabularis leaf oil exhibited strong antibiotic activities against Proteus vulgaris and Fusarium oxysporum and did not show any activity against the tested bacteria. Melia dubia leaf essential oil exhibited bacteriostatic and fungistatic activities against Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae and Fusarium oxysporum and Candida albicans respectively. The inhibitory activities of both essential oils are comparable with that of respective standards.     

Antibacterial activity of essential oils from Psidium and Pilocarpus species of plants

The antibacterial activity of six essential oils obtained from the leaves of Pilocarpus and Psidium species of plants have been studied. The leaf oils of Psidium guyanensis, Psidium pohlianum and Pilocarpus spicatus showed the most potent antibacterial activity (MIC 52.5–75.0 μg/mL) against Gram-negative Pseudomonas aeruginosa. Against Gram-positive Staphylococcus aereus, P. guyanensis demonstrated marked activity (MIC 75.0±15.0 μg/mL) followed by P. spicatus and Pilocarpus pauciflorus (MIC 100.0±28.9 μg/mL). The efficacy of some tested oils against P. aeruginosa, the most resistant organism may have significant clinical implication. © 1997 John Wiley & Sons, Ltd.     

Antifungal Activities of the Leaf Extract of Cassia tora Linn. (Fam. Leguminosae)

The antifungal activity of the dealcoholized extract of leaves of Cassia tora Linn. was determined on five different fungal organisms. The crude leaf extract significantly inhibited the growth of C. albicans, A. niger, S. cerevisiae and T. mentagophytes when tested by turbidity and spore germination methods in a concentration dependent fashion. The effects produced by the extract were compared with a standard antifungal agent griseofulvin.     

Butyryl- and acetyl-cholinesterase inhibitory activities in essential oils of Salvia species and their constituents

Extracts of Salvia (sage) species have been reported to have cholinergic activities relevant to the treatment of Alzheimer's disease. A lack of information on the inhibition of the enzyme butyrylcholinesterase, also considered to be a target in the treatment of the disease, prompted this in vitro investigation of the essential oils of S. fruticosa, S. lavandulaefolia, S. of ficinalis and S. of ficinalis var. purpurea for anti-butyrylcholinesterase activity. Dose-dependent inhibition of human cholinesterases by the extracts and constituents was determined using the method of Ellman. A time dependent increase in the inhibition of butyrylcholinesterase by the oils of S. fruticosa and S. of ficinalis var. purpurea was evident. IC(50) values decreased from 0.15 +/- 0.007 and 0.14 +/- 0.007 mg/mL after 5 min to 0.035 +/- 0.016 and 0.06 +/- 0.018 mg/mL after 90 min incubation time respectively. The slow onset of inhibition of butyrylcholinesterase was also shown by individual constituents, such as 3-carene and beta-pinene. Analyses of the chemical composition of the oils and anti-butyrylcholinesterase activity of their constituents revealed that none of the compounds tested would account for the total activity of the oils and that synergy is likely.     

Chemical composition and antimicrobial activity of the essential oils from two species of Eucalyptus

The leaf-essential oil from Eucalyptus robusta and E. saligna, the latter in two phenologic stages, were analysed by gas chromatography coupled to mass spectrometry (GC-MS). The major constituent in E. robusta oil was the monoterpene alpha-pinene (73.0% of the total amount). The oil composition of the E. saligna was dependent of the phenologic stage. In the vegetative phase, the major constituents were p-cymene (54.2%) and gamma-terpinene (43.8%), while during the blossoming alpha-pinene became the major constituent followed by p-cymene (22.5%). Additionally, the antimicrobial activity for all three oils was evaluated against Staphylococcus aureus, Escherichia coli and Candida albicans. The E. robusta oil presented the highest growth inhibition for all the microorganisms tested.     

Cytostatic activity against HEp-2 cells and antibacterial activity of essential oil from Helichrysum picardii

Different samples of essential oil from Helichrysum picardii Boiss. & Reuter (Compositae) collected at the beginning of each season from the same locality have been tested for their cytostatic and antimicrobial activity. All the oil samples showed a stronger in vitro activity against HEp-2 cells than a 6-mercaptopurine solution used as a positive control. Gram-positive bacteria as well as the fungus Candida albicans were sensitive to the action of the essential oil, whereas none of the samples showed activity against the gram-negative bacteria.     

Effects of Athamanta turbith fruit essential oils on CCl4‐induced hepatic failure in mice and their antioxidant properties

The effects of essential oils isolated from mature fruits of Athamanta turbith ssp. hungarica (Borbás) Tutin and A. turbith ssp. haynaldii (Borbás & Uechtr.) Tutin (Umbelliferae) on some liver biochemical parameters in mice intoxicated with carbon tetrachloride were investigated. Pretreatment with both essential oils extenuated the effects caused by carbon tetrachloride. In order to investigate in vitro antioxidant properties of the oils, three methods were applied: scavenging of both 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) and OH radicals, as well as a test of inhibition of Fe²⁺/ascorbic‐induced lipid peroxidation. Investigated essential oils exhibited modest antioxidant capacity. Therefore, their influence on biochemical parameters in intoxicated animals might be linked to the inhibition of enzymes (cytochrome P450 2E1) involved in metabolic activation of halomethanes. Copyright © 2009 John Wiley & Sons, Ltd.