Antimicrobial Activity Of Essential Oils Research Articles

Chemical composition and antimicrobial activities of essential oil and ethanol extract of <i>Cyperus fuscus</i> L burs from Turkey

Purpose: To investigate the chemical composition of the essential oil of Cyperus fuscus burs as well as the antimicrobial activities of the ethanol extracts and essential oil.Methods: Fresh burs roots of C. fuscus were collected at the flowering stage in an open area in Güdül (Ankara, Turkey). Preparation of the ethanol extract, hydrodistillation of the essential oil, GC-FID-MS analysis, and agar diffusion and MIC agar dilution assays were performed to determine various parameters for the oil and extracts.Results: The major compounds of the essential oil were dehydroaromadendrene (10.7 %), azulenone (8.5 %), α-selinene (7.5 %), α-ylangene (6.0 %) and β-caryophyllene (5.6 %). The essential oil of Cyperus fuscus exhibited activity against Gram-negative bacteria with minimum ınhibitory concentration (MIC) values ranging from 1000 to 31.25 μl/mL. Similarly, the ethanol extract of the burs showed good antimicrobial activity with the MIC of the ethanol extracts on ranging from 1000 μg/mL (Escherichia coli) to 250 μg/mL (Pseudomonas. Aeruginosa, p < 0.05). However, the ethanol extract was inactive against yeast strains.Conclusion: Thus, the essential oil and ethanol extract of the studied plant can potentially be used as antimicrobial agent.Keywords: Cyperus fuscus, Antimicrobial activity, Chemical composition, Essential oil

Chemical composition and antimicrobial activities of essential oils of Ruta graveolens plants treated with salicylic acid under drought stress conditions

This study aims to investigate the effect of foliar application of 0.0 and 1.5 mM salicylic acid (SA) under normal [100% field capacity (FC)] and reduced irrigation (75 and 50% FC) on the yield, chemical composition and antimicrobial activities of essential oils (EOs) obtained from leaves and flowers of Ruta graveolens L. in field condition. The highest yields of EOs (0.366 and 0.215% v/w for leaves and flowers, respectively) were obtained from plants grown in 50% FC treated with 1.5 mM SA. Similarly, EOs from the flowers of plants maintained under the same conditions provided the highest percentage of long chain methyl ketones (94.2%). Moreover, the percentage of 2-undecanone and 2-nonanone, the two major components of the EOs, varied between 52.52-58.10% and 18.00–25.14% for leaves as well as 70.22–84.57% and 3.00–7.44% for flowers, respectively according to the treatment. On the other hand, the obtained EOs exhibited significant antimicrobial activities with minimum inhibitory concentrations (MIC) of 3.5–7.94 μg/ml for the tested bacterial strains; Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Klebsiella pneumonia, and 1.14–2.5 μg/ml for the tested Candida species. Interestingly, a direct correlation between the percentage of long chain methyl ketones and the antimicrobial efficiency of EOs was observed. Furthermore, the most potent EO exerted concentration-dependent antimicrobial effects against all the bacterial and fungal strains in the killing kinetics studies. It also showed considerable morphological alterations on Candida albicans, including cell surface abnormalities, deformation, disruption, and prevented the germ tube production using scanning electron microscopy and germ tube test.

Seasonality effects on chemical composition, antibacterial activity and essential oil yield of three species of Nectandra.

In this study, we aimed to determine whether seasonality affects the content, chemical composition, and antimicrobial activity of essential oils (EOs) from the leaves of three species of Nectandra (Nectandra megapotamica, Nectandra grandiflora, and Nectandra lanceolata) native to the Atlantic rainforest, Sao Paulo state, Brazil. In addition, we identified the compounds potentially related to the antimicrobial activity. Leaves were randomly collected in the middle of winter (August), spring (November), summer (February), and autumn (May). The influence of seasonality on the content and chemical composition of EOs from the Nectandra species was evident in this study. The EOs from N. lanceolata and N. grandiflora were characterized by similarities in the chemical composition and had a higher relative proportion of oxygenated sesquiterpenes. N. megapotamica presented a different chemical profile, with plenty of monoterpenic and sesquiterpenic hydrocarbons. Changes in the EO chemical profile because of seasonality were shown by the similarities between the EOs obtained in spring and autumn and the differences between the EOs obtained in summer and winter. The EO from the leaves of N. megapotamica harvested in winter and spring showed the highest control of the growth of Escherichia coli, and this antimicrobial action can be related to the monoterpenes α-pinene and β-pinene as well as myrcene and limonene. The minimum inhibitory concentration (MIC) of the EO from the leaves of N. lanceolata harvested in summer and autumn was lower against the gram-positive bacterium Staphylococcus aureus and can be related to the sesquiterpene hydrocarbons isobicyclogermacrenal, epi-zizanone, and germacrene B.

Antimicrobial activity of essential oils against foodborne multidrug-resistant enterococci and aeromonads in planktonic and biofilm state.

The selection and use of natural compounds with antimicrobial activity against foodborne pathogens is of major importance. The present study evaluated the antimicrobial activity of commercial essential oils against multidrug-resistant Enterococcus spp. and Aeromonas spp. Cymbopogon flexuosus and Thymus vulgaris essential oils presented the highest inhibitory zones against both bacterial groups ( p < 0.05). Subsequent determination of the minimum inhibitory concentrations showed values between 0.47 and 1.9 mg/ml for Aeromonas spp. and from 1.9 to 15 mg/ml for Enterococcus spp. The antimicrobial effect of C. flexuosus and T. vulgaris essential oils was also assessed against biofilms. Bacteria in biofilm state were subjected to 30 min or 1 h of exposure to each essential oil and eradication ability estimated by colony counting. Both essential oils exhibited antimicrobial activity against preformed Aeromonas biofilms, but were unable to successfully eradicate biofilms produced by enterococci, in the conditions under investigation. Nonetheless, the presumptive use of essential oils in the food industry should be considered in further investigations.

Antimicrobial Activity of Five Essential Oils against Bacteria and Fungi Responsible for Urinary Tract Infections.

Urinary tract infections are frequently encountered in small animal practice. Escherichia coli and Enterococcus spp. are the most common agents associated to these infections, even though other bacteria and yeasts, such as Candida albicans and Candida famata, may be involved. In view of the increasing problem of the multi-drug resistance, the aim of this study was to investigate the antimicrobial activity of essential oils obtained from star anise (Illicium verum Hook.f.), basil (Ocimum basilicum L.), origanum (Origanum vulgare L.), clary sage (Salvia sclarea L.) and thymus (Thymus vulgaris L.) against multidrug-resistant strains of Escherichia coli, Enterococcus spp., Candida albicans and Candida famata previously isolated from dogs and cats with urinary tract infections. Enterococci were resistant to Illicium verum and Salvia sclarea, such as Candida to Salvia sclarea. Thymus vulgaris and Origanum vulgare essential oils showed the best activity against all the tested pathogens, so they could be proposed for the formulation of external and/or intravesical washes in small animals.

Anti-Biofilm Formation of &lt;i&gt;Streptococcus mutans&lt;/i&gt; by Jasmine Mouthwash

Streptococcus mutans has been reported to be a major causative microorganism for oral biofilm associated with dental caries. Jasmine sambac or Arabian jasmine is a species of jasmine native to tropical and warm temperate regions particularly West and Southeast Asia. The antimicrobial activities of essential oil extracted from the flowers of J. sambac have been shown to attract researchers. Objective: To determine the anti-biofilm formation of S. mutans by mouthwash containing jasmine oil. Materials and Methods: S. mutans KPSK2, the cariogenic strain of oral streptococci was used in the study. The 24-h biofilms of S. mutans were formed on polystyrene plates treated with jasmine mouthwash. The 0.2% chlorhexidine gluconate and phosphate buffer saline mouthwash were used as a positive and negative control respectively. The amount of biofilm was quantified by crystal violet staining and spectrophotometry at an optical density of 595 nm. Results: Jasmine mouthwash showed a significant inhibitory effect on S. mutans biofilm formation by decreasing 43% of biofilm whereas that of chlorhexidine showed 71% reduction. Conclusion: The anti-biofilm formation property of jasmine mouthwash was elucidated; therefore it might be another drug of choice that can be used as an adjunct to control the oral health in the prevention of dental caries.

Avaliação do efeito antimicrobiano, hipotensivo e diurético de extratos de Eugenia uniflora

The genus Eugenia sp. (Myrtaceae) comprises plants with reported antioxidant and antidiarrheal capability among other therapeutic potentials. The aim of this study was to evaluate the antimicrobial activity of essential oil; diuretic and hypotensive activities of aqueous extracts from leaves of Eugenia uniflora. The antimicrobial activity was evaluated . The diuretic and hypotensive activities were evaluated in normotensive Wistar rats by measuring blood pressure and urine flow after received four different concentrations of aqueous extracts (10%, 15%, 20% and 25%). Essential oil inhibited the growth of Candida parapsilosis and Candida albicans with MIC values lower than 14.41 mg/mL, equal to 57.75 mg/mL for Candida krusei. Among antibacterial effect, essential oil inhibited growth with a MIC equals to 153.93 mg/mL for all strains tested, except for Escherichia coli (MIC equals to 307.96 mg/mL. Aqueous extracts showed powerful reductions of the arterial pressure (34% and 31% lower than the control), after administration of 10% and 25% of aqueous extract, respectively. However, the animals that received the aqueous extract at the 15% and 20% concentrations presented a discrete hypotensive effect (20% and 21% lower than control group, respectively) concomitantly to powerful diuretic effect (280% and 91% higher than control group, respectively). These data confirmed the potential biological effect of this species, and represents an important step toward a depth study on the therapeutic properties of this species.

In vitro study on the activity of essential oil and methanolic extract from Algerian Nigella sativa L. Seeds on the growth kinetics of micro-organisms isolated from the buccal cavities of periodontal patients

An in vitro evaluation of the antimicrobial activity of essential oil (EO) and methanol extract (ME) from Algerian Nigella sativa L. seeds against microbial strains isolated from the oral cavities of periodontal patients was performed. Twelve Gram-positive bacteria, eleven Gram-negative bacteria and three microscopic fungi strains were isolated and identified. The antimicrobial activities of EO and ME were tested against Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, Enterococcus faecalis, Klebsiella pneumoniae, Proteus sp., Acinetobacter baumannii/calcoaceticus, Porphyromonas sp., Veillonella sp., Candida sp. and Saccharomyces sp.. The total polyphenol and flavonoids contents of ME were higher than those of EO. Thin layer chromatography showed that catechin, gallic acid and quercetin were most likely present in the extracts. Fourier transform infrared spectrometry analysis (FT-IR) indicated the presence of bands from the CO groups of acids, alcohols, phenols, and ethers and the CO band of aldehydes. Analysis of the antimicrobial activity of N. sativa extracts obtained by the microdilution method showed excellent bactericidal activity of the essential oil and moderate efficiency of the ME against all the microbes tested. Staphylococcus epidermidis and Porphyromonas sp. were the most sensitive to EO (minimum bactericidal concentration (MBC): 16,500 μg/ml) at 48 h of incubation and, 125,000 μg/ml of ME was the most active against all the microbes tested. However, after18 or 24 h, this efficiency was decreased in some strains. In addition, Saccharomyces sp. and Candida albicans were more sensitive to EO than ME during the incubation, while this efficiency was clearly not visible with the agar well method, and most microbes tested presented remarkable resistance to these extracts.

Species-specific antimicrobial activity of essential oils and enhancement by encapsulation in mesoporous silica nanoparticles

Essential oils are volatile plant compounds that are biologically active and play an important role in natural plant protection. There are currently ∼3000 essential oils known, of which over 300 are commercially important for a variety of industries. In fact, the essential oil global market has been estimated to reach 13.94 billion USD with a demand of over 370,000 tons by 2024. These compounds have a wide variety of applications in agriculture, food and beverage, cosmetics, medicine, amongst other industries. A promising application of essential oils is as antimicrobials to target the vast number of diseases affecting crops. However, their volatile nature limits their effective use as free agents. To overcome this, we have investigated the use of mesoporous silica nanoparticles to protect essential oils from evaporation and degradation and to enhance their antimicrobial activity against bacterial phytopathogens. Silica nanoparticles were used due to their potential to be produced at an industrial scale and their biocompatibility. As a proof of concept, we evaluated 41 essential oils against bacterial phytopathogen Pseudomonas syringae pv. pisi, causative agent of pea bacterial blight. Additionally, we compared the effect of such essential oils against Pectobacterium carotovorum subsp. carotovorum and Pseudomonas fluorescens. Two of the most effective antimicrobials, cinnamon (Cinnamomum zeylanicum) and mustard (Brassica nigra) oils, were able to inhibit bacterial growth after 24 h at a concentration as low as 0.016% (v/v). Besides efficacy, the species-specificity of essential oils was demonstrated with >67% of oils tested displaying specificity towards pathogenic P. syringae pv. pisi over non-pathogenic Pseudomonas fluorescens. Furthermore, the encapsulation of essential oils into mesoporous silica nanoparticles (MSNPs) as a means of extending and improving their antimicrobial effect was found to enable a 10-fold increase in potency compared to the free essential oil. Cinnamaldehyde immobilised onto MSNPs proved to be the most effective antimicrobial, eliminating >99.8%, >99.9%, and >95% bacterial growth of P. fluorescens, P. syringae pv. pisi and P. carotovorum subsp. carotovorum, respectively. This system has the potential to be used to treat and prevent bacterial infections in crops and to enable a more controlled and effective exploitation of volatile compounds as antimicrobials.

Investigation of antioxidant and antimicrobial activity of essential oil from Salvadora Persica (miswak)

Bu çalışmanın amacı; Salvadora persica (misvak) bitkisinden elde edilen uçucu yağın antioksidan ve antimikrobiyal etkilerini araştırmaktır. Bu bitkinin çalışılma sebebi; misvağın uzun zamandır tüm dünyada diş sağlığı ve temizliği alanında kullanılmasıdır. Bu çalışma farklı spektroskobik yöntemler ve GC-MS ile açıklamaya çalışıldı. Bu amaçla 250 gram misvak tozu, hidrodistilasyon yöntemi ile clevenger aparatında yağ ekstraksiyonu yapıldı, susuz Na2SO4 ile su uzaklaştırıldı ve 4 ͦ C buzdolabında yağlar saklandı. Uçucu yağ bileşenleri GC-MS ile tanımlandı. Uçucu yağların antimikrobiyal özellikleri disk difüzyon yöntemi ile Parvathy ve arkadaşları metoduna göre yapıldı. DPPH radikal süpürme ve Hidrojen peroksit süpürme kapasitesi spetkrofotometrik yöntem ile yapıldı. Farklı mineraller ve ağır metalleri ICP-MS ile analiz edildi.

Investigation of antimicrobial activities of some herbs containing essential oils and their mouthwash formulations

The aim of this study was to prepare pharmaceutical formulations of mouthwashes and to examine the antimicrobial activities of essential oils obtained from plants used traditionally in Turkey for oral infections. Essential oils were obtained from herbal drugs using water distillation with Clevenger apparatus. The antimicrobial capacities of mouthwash formulations containing a mixture of essential oils with proportions of 4.5% and 9.0% were examined using disc diffusion and microbroth dilutions. The inhibition zone diameters were determined to vary between 7 and 59 mm. The static and cidal activity was generally 50% and greater than 50% when pure essential oil samples were applied on microorganism specimens. Formulation F2, which contained a mixture of essential oils with proportions of 4.5%, showed 6.25% minimum bactericidal effect on Staphylococcus aureus ATCC 25923, and 3.125% the minimum inhibitory concentration and minimum bactericidal concentration on all other microorganisms. The antimicrobial effect of pure essential oil samples applied on microorganisms was lower than of mouthwashes formulations; the antimicrobial effect of F2, which contained a mixture of essential oils with proportions of 4.5% was higher than formulation F1, which contained a mixture of essential oils with proportions of 9%. The results obtained by these methods allow us to conclude that the essential oils and the prepared F1 and F2 mouthwash formulations exerted activity against microorganisms affecting the oral cavity. The F2 formulation also had significant antimicrobial activity on the tested microorganisms.

The Study of Essentials Oils Obtained from Thymus pannonicus L. - Microbiological Aspects

Abstract Essentials oils have been used over time in the food and cosmetics industry, but also in the medical and pharmaceutical industry. Environmental factors such as temperature, radiation and photoperiod play an extremely important role in the quantity and quality of volatile oils. It is also known that the vegetation stage can play an important role in the chemical composition of volatile oils. The purpose of this paper is to establish the antibacterial and antifungal activity of volatile oils of Thymus pannonicus, taking into account the ontogenetic stage in which the plants were collected, highlighting the compounds of therapeutic importance. To test the antimicrobial activity of essential oils two methods of work were used: Kirby-Bauer disc diffusion method and microplate method. The essential oils studies were tested on Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922 and Candida albicans. It was find that all essential oils tested have antimicrobial activity at all stages of development tested. The maximum antimicrobial activity has been recorded for the oils extracted from individuals collected at the anthesis stage.

The in vitro antimicrobial evaluation of commercially essential oils and their combinations against acne.

The study investigated the efficacy of commercial essential oil combinations against the two pathogens responsible for acne with the aim to identify synergy and favourable oils to possibly use in a blend. Antimicrobial activity was assessed using the minimum inhibitory concentration (MIC) assay against Staphylococcus epidermidis (ATCC 2223) and Propionibacterium acnes (ATCC 11827), and the fractional inhibitory concentration index (ΣFIC) was calculated. Combinations displaying synergistic interactions were further investigated at varied ratios and the results plotted on isobolograms. From the 408 combinations investigated, 167 combinations were identified as displaying noteworthy antimicrobial activity (MIC value ≤1.00 mg mL-1 ). Thirteen synergistic interactions were observed against S. epidermidis, and three synergistic combinations were observed against P. acnes. It was found that not one of the synergistic interactions identified were based on the combinations recommended in the layman's aroma-therapeutic literature. Synergy was evident rather from leads based on antimicrobial activity from previous studies, thus emphasizing the importance of scientific validation. Leptospermum scoparium J.R.Forst. and G.Forst (manuka) was the essential oil mostly involved in synergistic interactions (four) against S. epidermidis. Cananga odorata (Lam.) Hook.f. and Thomson (ylang ylang) essential oil was also frequently involved in synergy where synergistic interactions could be observed against both pathogens. The combination with the lowest MIC value against both acne pathogens was Vetiveria zizanioides Stapf (vetiver) with Cinnamomum verum J.Presl (cinnamon bark) (MIC values 0.19-0.25 mg mL-1 ). Pogostemon patchouli Benth. (patchouli), V. zizanioides, C. verum and Santalum spp. (sandalwood) could be identified as the oils that contributed the most noteworthy antimicrobial activity towards the combinations. The different chemotypes of the essential oils used in the combinations predominantly resulted in similar antimicrobial activity. The investigated essential oil combinations resulted in at least 50% of the combinations displaying noteworthy antimicrobial activity. Most of the synergistic interactions do not necessarily correspond to the recommended layman's aroma-therapeutic literature, which highlights a need for scientific validation of essential oil antimicrobial activity. No antagonism was observed.

Antioxidant properties and anti-quorum sensing potential of Carum copticum essential oil and phenolics against Chromobacterium violaceum

The chemical composition, antimicrobial and antioxidant properties of Carum copticum essential oil and its methanolic extract were investigated. Thirteen compounds were identified representing 99.3% of the total oil composition. Oxygenated monoterpenes (53.0%) dominated the C. copticum essential oil with high contents of thymol (51.7 ± 1.51%), p-cymene (26.9 ± 1.11%), γ-terpinene (16.7 ± 0.76%), and β-pinene (1.6 ± 0.15%). In the methanolic extract, the caffeic, gallic, chlorogenic, coumaric and ferulic acids, flavan-3-ols (catechin), flavone (hyperoside), and the flavonol quercetin were identified. Antimicrobial activity of essential oil and the organic extract was tested by disk diffusion and broth microdilution method. The essential oil was effective against the tested bacteria and yeast strains with the highest activity and the MICs and MBCs values were lower as compared to the methanolic extract. The essential oil showed anti-quorum sensing activity against Chromobacterium violaceum, and the IC50 value for violacein inhibition was 0.23mg/ml. Both the essential oil and the methanolic extract also showed antioxidant activities. The results obtained highlight the potential use of C. copticum as a possible source of antimicrobial and antioxidant compounds to be used both as food flavor and as a broad spectrum antibiotic.

POTENTIAL ANTIFUNGAL ACTIVITY OF ESSENTIAL OILS AND THEIR APPLICATION IN FOOD PRESERVATION

The quality of food is highly affected by different types of biological, chemical, and physical contaminants. Microbial contaminations that are transferred through direct or indirect pathways such as through saliva, pest droppings, blood, or fecal matter affect the quality of food worldwide. Food can be spoiled by bacteria as well as fungus. The fungal microbes secrete toxins to intoxicate the food material rendering it unfit for consumption. The objective of the present review is to explore the application of essential oil (EO) as potent antifungal agent and thus good sources of food preservative. We have reviewed previously published papers on antimicrobial activity of EOs. The antimicrobial activity of these natural plant products has been assayed by different approaches. Apart from their activity against microbes, the other beneficial effects of these plant products such as antioxidant activity and enhancing the food quality are also observed by various groups of scientists all over the globe. On the basis of results obtained by different researchers worldwide, the EOs can be authenticated as a food preservative. For the preservation of food, several chemicals are being used by different food industries at large scale; however, they have some limitations. Recently much attention has been directed toward the development of less or negligibly toxic ethno-products which may be utilized for human use for several purposes such as food preservatives, in cosmetics, and medicines. The plant-based volatile EOs and non-volatile secondary metabolites have wide applications in dietary supplements, food flavoring and preservation, folk medicine, and fragrance industry. Several reports have confirmed the antioxidant efficacy of plant-based EOs in vitro and in vivo. Application of plant materials as dietary supplements and preservatives is mainly due to their antioxidant, antimicrobial, and other biological as well as pharmaceutical potentials. Nowadays, EOs and their components are gaining increased attention because of their relatively safe status, their wide acceptance by consumers and the possibility of their exploitation for potential multipurpose uses. It will be relevant to extract EOs, since these extracted oils may have antimicrobial potential which can be utilized for their possible roles against food spoilage microbes.

Solid lipid nanoparticles carrying Eugenia caryophyllata essential oil: the novel nanoparticulate systems with broad-spectrum antimicrobial activity.

Microbial resistance to antibiotics is a major problem in the treatment of diseases. Therefore, overcoming antimicrobial resistance is an urgent need. Drug delivery via nanoparticles and applying natural products are promising approaches to reduce microbial resistance. This study is designed to evaluate the antimicrobial activity of solid lipid nanoparticles (SLN) containing Eugenia caryophyllata essential oil (EO) against human pathogens. The results indicated that the antimicrobial activity of EO was remarkably enhanced when encapsulated in SLN.

The study of essential oil on antimicrobial activity and their composition towards microorganism

In the course of the research, the microorganisms that often caused disease for animals were used, according to the literature, were genetically predisposed to resistance to traditional antibiotics and needed to find new effective means to combat them. It was used different antibiotic substances benzalkonium chloride, silver nanoparticles, and promising in this direction, essential oils of plants: fir, eucalyptus. The article provides information on the selection and study of the efficacy of substances, components with essential oils necessary for the development of complex bactericidal agents and the study of their antimicrobial activity against microorganisms. In determining the antimicrobial activity of essential oils, test cultures were used: Microccoccus luteus ATCC9341, Microccoccus lisogenicus, B. subtilis AATCC6633, B.cereus ATCC6633, S. aureus 209-P, S. zooepidemicus, Clebsiella spp, Salmonella cholerae suis, Pasterella multocida from the museum of State Scientific and Control Institute of Biotechnology and strains of microorganisms. The determination of fungicidal acity was performed on microscopic molds of Penicillium citrinum, Penicillium urticae, Aspergillus flavus, Aspergillus ochraceus. In experiments with Staphilococcus aureus, Streptococcus zooepidemicus, Pasteurella multocida, the antibiotic action of essential oils of eucalyptus and puff was confirmed and the possibility of its enhancement by the addition of quaternary ammonium compounds was confirmed. According to the results, the use as an alternative to antibiotics and disinfectants of preparations based on vegetable essential oils in the form of aerosols not only improves the number of animals from respiratory infections of bacterial origin, but also significantly improves the ecological conditions of the work of personnel in livestock buildings, promotes treatment and prevention respiratory diseases. The investigations have proved the expediency of using vegetable essential oils for the design of highly effective drugs and the possibility of enhancing their antimicrobial activity by quaternary ammonium compounds and silver nanoparticles, as well as a complex preparation «Asept» for aerosol application in the presence of animals.

Chemical composition and microbiological evaluation of essential oil from Hyssopus officinalis L. with white and pink flowers

AbstractHyssopus officinalis L. is a common plant that is most usually found in three color forms - f. cyaneus (blue), f. ruber Mill. (purple/pink) and f. albus Alef (white). In the present work, we evaluated the chemical composition and antimicrobial activity of essential oils obtained from Polish-sourced white- and pink-flowered H. officinalis. Gas chromatography-mass spectrometry analysis of the essential oil has shown that both forms of color have a different content of main components. The principle essential oil component of white-flowered H. officinalis L. was pinocamphone (51%), while pink-flowered H. officinalis L. contained almost equal amounts of pinocamphone (28.8%) and isopinocamphone (21.9%). Of note, the essential oil of the pink form was more active against Grampositive bacteria, especially against Bacillus subtilis.

Chemical composition and antimicrobial activities of essential oil from Wedelia urticifolia growing wild in Hunan Province, China

The essential oil obtained from Wedelia urticifolia growing in Hunan Province, China, was analyzed for the first time by capillary GC and GC-MS. A total of 67 constituents, representing 98.68% in essential oil were identified. The major constituents of the oil were: α-pinene (8.85%), limonene (6.38%), carvacrol (6.15%), caryophyllene (6.08%), spathulenol (5.49%), sabinene (5.36%), camphor (4.34%). Antimicrobial potential of oil against bacterial strains (Pseudomonas aeruginosa, Escherichia coli and Bacillus subtilis, and Staphylococcus aureus), yeast strains (Hansenula anomala and Saccharomy cescerevisiae) and molds (Aspergillus niger, Chaetomium globosum, Mucor racemosus, and Monascus anka) was determined by disc diffusion method and broth micro dilution method, respectively. The oil exhibited promising antimicrobial effect as a diameter of zones of inhibition (16.8–24.9 mm). Minimum inhibitory concentration values of oil were ranged 62.5–1000 μg/mL.

Antimicrobial activity and chemical composition of essential oil from Helichrysum microphyllum Cambess. subsp. tyrrhenicum Bacch., Brullo & Giusso collected in South-West Sardinia.

The aim of this study was to evaluate the chemical composition and the antimicrobial activity of essential oils of Helichrysum microphyllum subsp. tyrrhenicum collected in four different stations in South-Western Sardinia.The composition of the essential oils was determined by gas chromatography and gas chromatography/mass spectrometry. The oil samples showed different chromatographic profiles. The oil of the station 4 revealed the presence of significant amount of neryl acetate (33.6%); in oils from stations 1 and 2 we found γ-curcumene (28%) and in station 3 γ-curcumene (12%) and linalool (11%), while there was no trace of neryl acetate. Standard microbiological assays demonstrated that essential oils obtained by plants collected in station 1 and 2, very rich in curcumene, showed an interesting anticandidal activity, dose- and time-dependent, which is enhanced by sub-inhibitory concentrations of chitosan.Our results suggest that the essential oil of Helichrysum microphyllum subsp. tyrrhenicum, associated with chitosan in innovative formulations, could be considered as a therapeutic alternative in the treatment of Candida opportunistic infections. The results of this study shows that the chemotypization of the species examined could lead to their targeted clinical use, in a concept of a rational scientific aromatherapy.