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Investigation of the chemical composition-antibacterial activity relationship of essential oils by chemometric methods
Abstract
The antibacterial effects of Thymus vulgaris (Lamiaceae), Lavandula angustifolia (Lamiaceae), and Calamintha nepeta (Lamiaceae) Savi subsp. nepeta var. subisodonda (Borb.) Hayek essential oils on five different bacteria were estimated. Laboratory control strain and clinical isolates from different pathogenic media were researched by broth microdilution method, with an emphasis on a chemical composition-antibacterial activity relationship. The main constituents of thyme oil were thymol (59.95%) and p-cymene (18.34%). Linalool acetate (38.23%) and beta-linalool (35.01%) were main compounds in lavender oil. C. nepeta essential oil was characterized by a high percentage of piperitone oxide (59.07%) and limonene (9.05%). Essential oils have been found to have antimicrobial activity against all tested microorganisms. Classification and comparison of essential oils on the basis of their chemical composition and antibacterial activity were made by utilization of appropriate chemometric methods. The chemical principal component analysis (PCA) and hierachical cluster analysis (HCA) separated essential oils into two groups and two sub-groups. Thyme essential oil forms separate chemical HCA group and exhibits highest antibacterial activity, similar to tetracycline. Essential oils of lavender and C. nepeta in the same chemical HCA group were classified in different groups, within antibacterial PCA and HCA analyses. Lavender oil exhibits higher antibacterial ability in comparison with C. nepeta essential oil, probably based on the concept of synergistic activity of essential oil components.
... CN is well-known for its medicinal uses as a stimulant, tonic, antiseptic and antispasmodic [11,13,26,36,44,45]. The chemical composition of its EO has been thoroughly investigated [13,[44][45][46][47][48][49][50][51][52], as well as EO antioxidant [11,17,53,54], antimicrobial [11,17,27,51,[55][56][57][58][59], and anti-inflammatory activities [11,53]. In the folk medicine of different countries of the world, CN has also been widely used against insomnia, depression, convulsion and cramps [36,60] and for the treatment of respiratory and gastroenteric diseases [11,61]. ...
... The material from Serbia was rich in PUL (75.5%), piperitenone oxide (6%), menthone (5.3%) and menthol (4.3%) [33], while another study showed the predominance of piperitone oxide (59.09%), with limonene (9.05%), cis-sabinene hydrate (4.45%) and 4-terpineol (4.77%) among others [59]. ...
... However, due to indiscriminate use of antimicrobial synthetic chemicals in their treatment, both human and plant pathogenic microorganisms have developed resistance to multiple drugs/chemical substances. In addition, these chemical compounds can cause undesirable effects on environment because of their slow biodegradation and serious side effects on mammalian health because of toxic residues in agricultural products [59,84,101,102]. Consequently, there is an increased interest in developing new antimicrobial drugs from various natural sources, especially aromatic and medicinal plants. ...
Medicinal plants play an important role in the treatment of a wide range of diseases, even if their chemical constituents are not always completely recognized. Observations on their use and efficacy significantly contribute to the disclosure of their therapeutic properties. Calamintha nepeta (L.) Savi is an aromatic herb with a mint-oregano flavor, used in the Mediterranean areas as a traditional medicine. It has an extensive range of biological activities, including antimicrobial, antioxidant and anti-inflammatory, as well as anti-ulcer and insecticidal properties. This study aims to review the scientific findings and research reported to date on Calamintha nepeta (L.) Savi that prove many of the remarkable various biological actions, effects and some uses of this species as a source of bioactive natural compounds. On the other hand, pulegone, the major chemical constituent of Calamintha nepeta (L.) Savi essential oil, has been reported to exhibit numerous bioactivities in cells and animals. Thus, this integrated overview also surveys and interprets the present knowledge of chemistry and analysis of this oxygenated monoterpene, as well as its beneficial bioactivities. Areas for future research are suggested.
... In practice, a concurrent consideration of essential oils and their activities is common but only for small number of aromatic plants (maximum three) of closely related or similar taxa [10]. In scientific literature, examples of comparative studies of more plants classified in different genera (e.g., Mentha, Melissa, Ocimum, and Oregano) or in different families (Lamiaceae, Asteracceae, and Apiaceae) are very rare because of overly complex relationships between the activity and chemical composition of the samples studied [11][12][13][14]. ...
... The studied data were organized in the data matrix X(10 × 48), where rows correspond to 10 studied Lamiaceae representatives (Table I), whereas columns represent chemical composition (parameter numbers 1-8), antioxidant activity (parameter numbers 9 and 10), antifungal (parameter numbers [11][12][13][14][15][16][17][18][19][20][21][22], and antibacterial activity (parameter numbers 23-48) of the essential oils, listed in Table II. The comparison of the studied Lamiaceae species was performed for centered and standardized data X c (10 × 48) using MATLAB software, version 6.1.0.450. ...
... Namely, M. aquatica (object number 4) differs from S. nemorosa, S. officinalis, and Or. vulgare (object numbers 1, 3, and 8) mainly because of its low content of sesquiterpene hydrocarbons and oxygenated sesquiterpenes, as well as because both the antifungal activities of essential oils (parameter numbers 5, 6, and[11][12][13][14][15][16][17][18][19][20][21][22], and the lowest antibacterial activities of essential oils against Gram-negative Salmonella typhi (IPH-MR, 20%), and Gram-positive strains: Sarcina lutea (ATCC 9341, 20%), Micrococcus flavus (ATCC 10240, 20%), Staphylococcus epidermidis (ATCC 12228, 20%), Sa. typhi (IPH-MR, 20%), St. epidermidis (ATCC 12228, 50%) (parameter numbers 29, 31, 32, 34, 42, and 47, respectively). ...
The application of chemometric approaches in the comparison of the activity and the chemical composition of essential oils of 10 aromatic Lamiaceae species (Melissa officinalis, Mentha piperita, Mentha aquatica, Mentha longifolia, Ocimum basilicum, Origanum vulgare, Rosmarinus officinalis, Salvia officinalis, Salvia nemorosa, and Thymus vulgaris) is reported in this paper. The standard methodology of principal component analysis needs too many principal components (PCs) to effectively describe the relationships between studied samples. PC1 explains only 47.58% of the total variance reflecting the most significant differences between essential oils of S. nemorosa and Or. vulgare. PC2 explains 19.77% of the total variance and shows the most significant differences between the essential oils of M. aquatica compared with those of S. nemorosa, S. officinalis and Or. vulgare. Efficient compression of the data was possible by hierarchical clustering analysis (HCA) complemented with a color map. HCA shows that essential oils of both investigated representatives of genus Salvia are characterized by a high content of oxygenated sesquiterpenes and remarkable antifungal activities, but low antibacterial and antioxidant activity, particularly for the S. officinalis. Unlike sage, the essential oils of oregano and thyme have high content of aromatic oxygenated monoterpenes and low antifungal but pronounced antibacterial activity. Peppermint, basil, rosemary, and lemon balm are characterized by high content of oxygenated monoterpenes and aliphatic components as well as by high antioxidant 2,2-diphenyl-1-picrylhydrazil activity of essential oils. Copyright
... The genus Thymus contains about 350 species, most commonly used in traditional medicine as antibacterial and antifungal remedies (Miladinović et al., 2012b). The Serbian flora recognizes 30 species of the Thymus genus (Diklić, 1974). ...
... To eliminate any kind of subjective analysis, interpretations and discussions of the results, presented by tables or/and graphics, the chemometric methods: principal component analysis and hierarchical cluster analysis were employed. Furthermore, the use of chemometric methods allows the maximum number of experimental results to be obtained, and moreover is also easier to detect connections, similarities and differences among variables in the researched experimental system (Miladinović et al., 2012b). ...
... Obviously thymol exhibits a higher antibacterial activity than geraniol (Gallucci et al., 2010). However, the synergism of the components of an essential oil should not be ignored (Miladinović et al., 2012b). ...
... Cette différence de diversité est due à l'état physiologique de la plante hôte en étant affectée par la saison (en raison de facteurs tels que l'eau, la période d'éclairage, la température, etc.), l'emplacement et l'âge [20]. Cette variation a été également constatée par Li et al. [21] [26], qui ont confirmé l'utilisation de l'huile de lavande comme un agent antibactérien car elle contient des composés oxydants terpènes oxygénés qui ont une activité antimicrobienne, et il a été également prouvé dans la même étude que l'effet des huiles sur les bactéries Gram-positifs diffère de son effet sur les bactéries à Gram négatif. Les huiles essentielles sont trouvées pour affecter les propriétés structurelles et fonctionnelles de membranes artificielles. ...
... Les composants des huiles essentielles ont été montrés pour perméabiliser les membranes, les faisant gonfler, les bactéries à Gram négatif sont généralement plus résistantes aux antiseptiques et désinfectants que les bactéries à Grampositif. La membrane externe des bactéries à Gram négatif agit comme une barrière qui limite l'entrée de nombreux types d'agents antibactériens sans rapport chimique [26]. Bachiri et al. [27], ont avancé quant au mode d'action des HEs sur les cellules bactériennes, il semble plus probable que l'activité antimicrobienne résulte de l'association conjointe de plusieurs mécanismes sur différentes cibles cellulaires. ...
Description du sujet : La plante médicinale Lavandula officinilis est intéressante de connaitre sa vertu thérapeutique, afin de remplacer les produits synthétiques par des molécules bioactives qui sont à base de plantes. Objectifs : L'objectif de cette étude est l'isolement et l'identification des champignons endophytes plus l'extraction de l'huile essentielle de la plante médicinale L. officinilis, collectée de la région de Constantine (Algérie). Puis d'évaluer et comparer l'activité antibactérienne et antifongique de ces champignons et l'huile essentielle contre trois bactéries pathogènes : deux à Gram positif ; Bacillus sp., Staphylococcus aureus, et une à Gram négatif ; Pseudomonas fluorescence, ainsi que le champignon pathogène Fusarium oxysporum. Méthodes : L'extraction de l'huile essentielle a été effectuée par hydro distillation. La méthode de diffusion sur milieu gélosé et la méthode de la double culture ont permis de mettre en évidence le pouvoir antibactérien et antifongique, respectivement, de l'huile essentielle et des champignons endophytes, vis-à-vis les souches bactériennes testées par déterminer les diamètres des zones d'inhibition. Résultats : Le pourcentage de colonisation était 40,55%. La purification et l'étude microscopique des souches isolées ont donné la possibilité d'identifier 5 genres de moisissures à savoir Fusarium, Penicillium, Alternaria, Aspergillus ainsi qu'un Mycélium stérile. L'extraction de l'huile essentielle de la plante a été réalisée par hydro distillation, où le rendement a été estimé à 1,5%. En utilisant la méthode de diffusion sur milieu solide, il a été constaté que certains champignons endophytes ont une activité antimicrobienne sur au moins un microorganisme pathogène, où les zones d'inhibition variaient entre 0-39,5 mm, cette dernière a été obtenu par l'isolat Mycélium stérile, et Aspergillus niger avec 28,5mm, contre Bacillus sp., Toutefois, l'huile essentielle avait une activité contre toutes les bactéries pathogènes testées. Quant au test d'activité antifongique par la méthode de la double culture, il a été constaté que les deux champignons endophytes Aspergillus niger et Penicillium sp. ont un effet inhibiteur sur le champignon pathogène testé, où le pourcentage d'inhibition a été estimé à 61,55% , 41% respectivement. Alors que l'huile essentielle était moins efficace 12 mm. Conclusion : Les champignons endophytes ont une activité antifongique plus élevée par rapport à l'huile essentielle qui a une meilleure activité antibactérienne. Par conséquent, la plante médicinale et les champignons endophytes pourraient être une source prometteuse de composés bioactifs. L'ensemble de ces résultats obtenus ne constitue qu'une première étape dans la recherche des molécules d'origine naturelle biologiquement actives Mots clés : Lavandula officinalis ; champignons endophytes ; huile essentielle ; activité antibactérienne ; activité antifongique. Abstract Description of the subject: The medicinal plant Lavandula officinalis is interesting to know its therapeutic virtues, to replace the synthetic products by bioactive substances, which are with plants. Objective: Isolation and identification of endophytic fungi, and the extraction of essentielle oil from the medicinal plant L. officinilis, collected from the region of Constantine (Algeria). Then to evaluate and compare their antibacterial and antifungal activities against three pathogenic bacteria: two Gram-positive; Bacillus sp., Staphylococcus aureus, and one Gram-negative; Pseudomonas fluorescence, as well as the pathogenic fungus Fusarium oxysporum. Methods: The extraction of the essential oil was carried out by hydro distillation. The method of diffusion on agar medium and the method of double culture allowed highlighting the antibacterial and antifungal activities, respectively, of the essential oil and the endophytic fungi against the bacterial strains tested by determining the diameters of the inhibition zones. Results: The percentage of colonization was 40.55%. The purification and microscopic study of the isolated strains gave the possibility of identifying five genera, which are Fusarium, Penicillium, Alternaria, Aspergillus as well as a sterile Mycelium. The extraction of the essential oil from the plant was carried out by hydro distillation, where the yield was estimated at 1.5%. It was found that some endophytic fungi have antimicrobial activity on at least one pathogenic microorganism, where the zones of inhibition ranged between 0-39.5 mm, the latter was obtained by the sterile Mycelium isolate, and Aspergillus niger with 28.5mm, against Bacillus sp., however, the essential oil had activity against all pathogenic bacteria tested. As for the antifungal activity test by the double culture method, it was found that the two endophytic fungi Aspergillus niger and Penicillium sp. have an inhibitory effect on the tested pathogenic fungus, where the percentage of inhibition was estimated at 61.55%, 41% respectively. While essential oil was less effective (12 mm). Conclusion: Endophytic fungi have higher antifungal activity compared to essential oil, which has better antibacterial activity. Therefore, the medicinal plant and endophytic fungi could be a promising source of bioactive compounds. All of these results obtained constitute only a first step in the research for biologically active molecules of natural origin.
... For EO, the yield recorded in our study is higher than that found in the essence of C. nepeta (0.60%) [28], and Calamintha umbrosa Benth oil (0.1%) [29]. The yield of C. nepeta essential oil found by Dragoljub et al. [30] was 1.5%; this value tends to correlate with that found in the present study. ...
... Nevertheless, caryophyllene was also mainly found in C. umbrosa oils originating from India (13.9%) [29], which is higher than that found in the present study (1.02%). Also, C. nepeta essential oils were characterized by a high percentage of piperitone oxide (59.07%) and limonene (9.05%) [30], being higher than that recorded in our study. The composition of the EOs of the studied plant tends to be different compared to that reported by previous studies. ...
Background: Essential oils, infusion and decoction extracts of Calamintha nepeta L. were evaluated for their bioactive substances (polyphenols and essential oils) and antioxidant activities.
Methods: The amounts of phenolic compounds were determined by colorimetric assays and identified by high performance and liquid chromatography coupled with ultraviolet detector (HPLC-UV) method. The chem- ical composition of essential oils was determined by gas-chromatography coupled with mass spectrometry (GC/MS) method. For the evaluation of the antioxidant activity of essential oils and extracts, two different assays (reducing power and DPPH radical scavenging activity) were used.
Results: Infusion extract presented the highest phenolic content, followed by the decoction one, while the lowest amount was observed in essential oils. The amount of flavonoids of the decocted extract was higher than that of the infused one. The phenolic profile of C. nepeta infusion and decoction extracts revealed the presence of 28 and 13 peaks, respectively. Four phenolics compounds were identified in infusion (gallic acid (GA), rosmarinic acid (RA), caffeine (C) and caffeic acid (CA)) and two were identified in decoction (GA and RA). The chemical composition of essential oils revealed the presence of 29 compounds, accounting for the 99.7% of the total oils. Major compounds of essential oil (EO) were trans-menthone (50.06%) and pulegone (33.46%). Infusion and decoction extracts revealed an interesting antioxidant activity which correlates positively with their total phenolic contents.
Conclusions: These results showed that Calamintha nepeta could be considered as a valuable source of phenolics and essential oils with potent antioxidant activity.
... For EO, the yield recorded in our study is higher than that found in the essence of C. nepeta (0.60%) [28], and Calamintha umbrosa Benth oil (0.1%) [29]. The yield of C. nepeta essential oil found by Dragoljub et al. [30] was 1.5%; this value tends to correlate with that found in the present study. ...
... Nevertheless, caryophyllene was also mainly found in C. umbrosa oils originating from India (13.9%) [29], which is higher than that found in the present study (1.02%). Also, C. nepeta essential oils were characterized by a high percentage of piperitone oxide (59.07%) and limonene (9.05%) [30], being higher than that recorded in our study. The composition of the EOs of the studied plant tends to be different compared to that reported by previous studies. ...
Background
Essential oils, infusion and decoction extracts of Calamintha nepeta L. were evaluated for their bioactive substances (polyphenols and essential oils) and antioxidant activities.
Methods
The amounts of phenolic compounds were determined by colorimetric assays and identified by high performance and liquid chromatography coupled with ultraviolet detector (HPLC-UV) method. The chemical composition of essential oils was determined by gas-chromatography coupled with mass spectrometry (GC/MS) method. For the evaluation of the antioxidant activity of essential oils and extracts, two different assays (reducing power and DPPH radical scavenging activity) were used.
Results
Infusion extract presented the highest phenolic content, followed by the decoction one, while the lowest amount was observed in essential oils. The amount of flavonoids of the decocted extract was higher than that of the infused one. The phenolic profile of C. nepeta infusion and decoction extracts revealed the presence of 28 and 13 peaks, respectively. Four phenolics compounds were identified in infusion (gallic acid (GA), rosmarinic acid (RA), caffeine (C) and caffeic acid (CA)) and two were identified in decoction (GA and RA). The chemical composition of essential oils revealed the presence of 29 compounds, accounting for the 99.7% of the total oils. Major compounds of essential oil (EO) were trans-menthone (50.06%) and pulegone (33.46%). Infusion and decoction extracts revealed an interesting antioxidant activity which correlates positively with their total phenolic contents.
Conclusions
These results showed that Calamintha nepeta could be considered as a valuable source of phenolics and essential oils with potent antioxidant activity.
... A significant percentage of antagonistic activity recorded for the geraniol-tetracycline combination can indicate that the presence of trace components in the essential oil could possibly influence the antibacterial activity of the oil-selected antibiotic combination to a significant extent. In this case, changes of varying intensity of the antibacterial activity of the essential oil can be expected, with regard to the dominant component [11]. ...
... The experimental data (FIC values) were analyzed by chemometric methods: principal components analysis (PCA) and hierarchical cluster analysis (HCA), using Mathworks MATLAB [11]. ...
The chemical composition and antibacterial activity of Satureja kitaibelii Wierzb. ex Heuff. (savory) essential oil were examined, as well as the association between it and standard antimicrobials: tetracycline and chloramphenicol. The antibacterial activities of geraniol, the main constituent of S. kitaibelii oil, individually and in combination with standard antimicrobials were also determined. The interactions of the essential oil and geraniol with antimicrobials toward five selected strains were evaluated using the microdilution checkerboard assay in combination with chemometric methods. Oxygenated monoterpenes were the most abundant compound class in the oil (59.7%), with geraniol (50.4%) as the major compound. The essential oil exhibited in vitro antibacterial activity against all tested bacterial strains, but the activities were lower than those of the standard antimicrobials. The combinations savory oil-chloramphenicol, savory oil-tetracycline and geraniol-chloramphenicol produced predominantly synergistic interactions (FIC indices in the range 0.21-0.87) and substantial reductions in the MIC values of antimicrobials against Gram-negative bacteria, the pharmacological treatment of which is very difficult nowadays. In the PCA and HCA analyses these combinations form a separate group.
... The genus Thymus contains about 350 species, most commonly used in traditional medicine as antibacterial and antifungal remedies [4]. The Serbian flora recognizes 30 species of the Thymus genus, with more than 60 varieties [5]. ...
... To eliminate any kind of subjective analysis, interpretations and discussions of the results, presented by tables and/or graphics, and the chemometric methods: principal component analysis, and hierarchical cluster analysis were employed. Furthermore, the use of chemometric methods allows the maximum number of experimental results to be obtained and moreover enables the detection of connections, similarities, and differences among variables in the researched experimental system [4]. ...
The chemical composition and antibacterial activity of Thymus glabrescens Willd. (Lamiaceae) essential oil were examined, as well as the association between it and chloramphenicol. The antibacterial activities of geraniol and thymol, the main constituents of T. glabrescens oil, individually and in combination with chloramphenicol, were also determined. The interactions of the essential oil, geraniol, and thymol with chloramphenicol toward five selected strains were evaluated using the microdilution checkerboard assay in combination with chemometric methods. Oxygenated monoterpenes were the most abundant compound class in the oil, with geraniol (22.33%) as the major compound. The essential oil exhibited in vitro antibacterial activity against all tested bacterial strains, but the activities were lower than those of the standard antibiotic and thymol. A combination of T. glabrescens oil and chloramphenicol produced a strong synergistic interaction (FIC indices in the range 0.21–0.87) and a substantial reduction of the MIC value of chloramphenicol, thus minimizing its adverse side effects. The combinations geraniol-chloramphenicol and thymol-chloramphenicol produced synergistic interaction to a greater extent, compared with essential oil-chloramphenicol association, which may indicate that the activity of the thyme oil could be attributed to the presence of significant concentrations of geraniol and thymol.
... Thus, it is necessary to develop alternative natural and safe methods for controlling infections of human body [1]. A wide variety of essential oils is known to possess antimicrobial properties [2,3]. The type of antimicrobial activity shown by essential oils and their components varies from partial or complete inhibition of growth to bactericidal activity [4]. ...
... Various components of an essential oil may have different modes of antibacterial action and/or that metabolism of some bacteria is able to better adapt to the oil [2]. In our research, aliphatic esters (69.55%) exhibit a weak antibacterial activity, which is in agreement with literature data [9]. ...
The composition and antimicrobial activity of the essential oil of Heracleum sibiricum L. (Apiaceae) was studied. The aerial part of plant was hydro-distilled and chemical composition of the essential oil was analyzed by GC and GC-MS. Forty-six compounds, corresponding to 95.12% of the total oil, were identified. Esters represented the major chemical class (69.55%) while the main constituents were octyl butanoate (36.82%), hexyl butanoate (16.08%), 1-octanol (13.62%) and octyl hexanoate (8.10%). Antibacterial activity of the essential oil and reference antibiotics against nine bacterial strains was tested by the broth microdilution method. The results of the bioassays showed that essential oil had slight antimicrobial activities against all tested microorganisms (MIC and MBC values were in the range of 2431.2 to 9724.8 microg/mL). Reference antibiotics were active in concentrations between 0.5 and 16.0 microg/mL. The results confirm that Gram-positive bacteria were more susceptible to the essential oil of H. sibiricum, in comparison with Gram-negative bacteria.
... These activities may be related to the activity of their terpenoid constituents (Cardia et al., 2018;Generoso et al., 2017;Miladinović et al., 2012;. ...
The natural products extracted from plants are part of traditional medicine and are also therapeutic possibilities for treating many diseases. Recently, its use in the development of new drugs has shown much visibility for its efficiency and few adverse effects. Essential oils extracted from medicinal plants are indicated to treat numerous diseases due to their antimicrobial, antiviral, antimutagenic, anticancer, antioxidant, anti-inflammatory, immunomodulatory, and antiprotozoal properties. Among essential oils, lavender essential oil stands out for having several important pharmacological properties. This review detailed the main studies on essential oils from different species of lavender and obtained a valuable collection on all their pharmacological, medicinal and toxicological potential. In this context, we evaluated lavender essential oil as a promising substance that can help treat several diseases. We provide some evidence and an overview of the potential therapeutic effect of lavender essential oil to guide new research.
... LEOs (primarily Lavandula angustifolia) have been shown to possess an extensive array of biological properties such as analgesic, antimutagenic, anti-inflammatory, anxiolytic, and a range of antimicrobial benefits [26][27][28][29][30]. Furthermore, combinatorial therapies incorporating the use of EOs has been shown by numerous in vitro studies to drastically potentiate the bactericidal effects against the MDR pathogens, which can be potential approaches in mitigating AMR [31,32]. Such strategies can be adopted via a few different combinations: (i) combination of different natural adjuvants (i.e., combining LEO with one or more types of EOs), (ii) incorporation of LEO into conventional antibiotics, (iii) optimization of LEO with inclusion of nanoparticles [33]. EOs (including LEOs) have poor oral bioavailability and are chemically unstable to oxygen and humidity, which may limit their application as potential novel antimicrobial agents [34]. ...
Antimicrobial resistance (AMR) has been identified as one of the biggest health threats in the world. Current therapeutic options for common infections are markedly limited due to the emergence of multidrug resistant pathogens in the community and the hospitals. The role of different essential oils (EOs) and their derivatives in exhibiting antimicrobial properties has been widely elucidated with their respective mechanisms of action. Recently, there has been a heightened emphasis on lavender essential oil (LEO)’s antimicrobial properties and wound healing effects. However, to date, there has been no review published examining the antimicrobial benefits of lavender essential oil, specifically. Previous literature has shown that LEO and its constituents act synergistically with different antimicrobial agents to potentiate the antimicrobial activity. For the past decade, encapsulation of EOs with nanoparticles has been widely practiced due to increased antimicrobial effects and greater bioavailability as compared to non-encapsulated oils. Therefore, this review intends to provide an insight into the different aspects of antimicrobial activity exhibited by LEO and its constituents, discuss the synergistic effects displayed by combinatory therapy involving LEO, as well as to explore the significance of nano-encapsulation in boosting the antimicrobial effects of LEO; it is aimed that from the integration of these knowledge areas, combating AMR will be more than just a possibility.
... Lavandula oil has been observed to be dynamic against numerous types of microscopic organisms, including those impervious to anti-microbial, for example, methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE) (Cavanagh and Wilkinson, 2002). The capacity of oil to disturb the porousness membranous structure of cell, in this way interfering with the chemoosmotic control is the most conceivable explanation behind its deadly activity against bacteria (Miladinovic et al., 2012). Due to lavender oil' antifungal property it has medicinal and also plant health benefits by inhibiting the growth of germ tube or control diseases (Cavanagh and Wilkinson, 2005). ...
Lavender plant is perennial flowering aromatic herb that belongs to Lavandula genus native to Northern Africa and the upper hilly regions of Mediterranean for its flowers and extraction of oils. In India, it is cultivated in low rainfall regions and on slopes of Himachal Pradesh and Uttar Pradesh. However, it is successfully grown in Kashmir Valley region. Lavender oil mainly contains 40% linalyl acetate and 30% linalol. One is terpene alcohol and later one is the acetate ester of linalool and both having anti-microbial activities and provide a remarkable value to the lavender. Other constituents of the oil are cineol, pinene, limonene, geraniol, borneol and some tannin. In addition to cosmetic values, lavender has been found successfully a relief from anxiety, insomnia, depression, menstrual pain, headache, healing of wounds, muscle relaxation and pain after surgery. Recent studies by the researchers suggest that the lavender oil is effective in treatment of hair fall, acne and eczema for good skin health and consuming lavender as a tea has shown aromatherapy over can help digestive issues such as vomiting, nausea, intestinal gas, upset stomach, and abdominal swelling.
... This method is highly dependent on water solubility and the ability of test components to diffuse through an agar and inhibits the growth of the test microorganism. Thus, it would be expected that compounds of lower water solubility would show less activity, even if solubility did not affect their activity in other situations [12]. However, since the bacterial growth inhibition does not mean bacterial death, this method cannot https://doi.org ...
The susceptibility of Helicobacter pylori to three essential oils (EOs), 12 naturally occurring monoterpene hydrocarbons, oxygenated and phenolic monoterpenes and three reference antibiotics were studied. Classification and comparison of essential oils and monoterpenes on the basis of their chemical composition and antibacterial activity were made by the utilization of principal component analyses (PCA) and agglomerative hierarchical clustering (AHC). The most abundant compound in the Thymus glabrescens Willd. and Thymus pulegioides L. EOs is geraniol (33.8% and 52.5%), while the main constituent in Satureja kitaibelii Wierzb. ex Heuff. EO is limonene (16,1%). The compound that was the most active against H. pylori was carvacrol. EOs of T. glabrescens and S. kitaibelii exhibit higher antibacterial ability in comparison with all monoterpenes, except carvacrol, probably based on the concept of synergistic activity of essential oil components. PCA separated essential oils based on chemical composition and explain 96.5% of the total variance in the first two principal components. Essential oils, phenolic monoterpenes and two antibiotics were classified in the same sub-cluster within AHC analyses. EOs of T. glabrescens and S. kitaibelii can be used to treat infections caused by H. pylori, as a potentially effective, cheap and safe natural products. Further research of antibacterial activity of selected monoterpenes, essential oils and standard antibiotic combinations, as well as clinical study are required.
... The resulting essential oil is hereafter referred to as thermomechanical pulp turpentine (TMP-T). Essential oils from various sources have previously shown inhibitory or biocidal effects on an array of different organisms: parasites (Izumi et al. 2012), bacteria (Miladinovic et al. 2012), moulds (Akgül and Kivanç 1989), insects (Boulogne et al. 2012) and filamentous fungi (Inouye et al. 1998). Additionally, they are generally considered safe for humans and have found long-term use in drug formulations, food preservation and as flavouring agents (Bakkali et al. 2008;Smith et al. 2005). ...
Synthetic and heavy metal antifungals are frequently used as wood preservatives. However, they exhibit relatively inert biodegradation and toxic properties when leached; this makes their replacement with environmentally degradable yet functional alternatives a key target in the wood protection industry. In this context, distilled fractions of raw thermomechanical pulp turpentine (TMP-T) from Picea abies were assessed for their wood protecting capabilities against wood-decaying fungi. Antifungal bioactivity of fractions and some of their combinations were screened on agar-plates against the brown-rot fungus Coniophora puteana. Addition of TMP-T fractions showed a significant fungal growth rate reduction, while mixtures indicated the presence of synergistic and antagonistic effects. One fraction, obtained after distilling 1 L TMP-T at 111–177 °C at 0.5 mbar, showed complete growth inhibition of Antrodia sinuosa, Serpula lacrymans, Serpula himantioides and significant inhibition of Antrodia serialis, Antrodia xantha, Gloeophyllum sepiarium, Heterobasidion parviporum at a concentration of 1000 ppm. This fraction was further examined for long- and medium-term effects on wood decay in microcosm soil-jar and field experiment, respectively. The known antifungal compounds benzisothiazolinone, 2-octyl-4-isothiazolin-3-one, 3-iodo-2-propynyl N-butylcarbamate and two commercial wood preservatives were used as reference treatments. Commercial preservatives instilled long-term efficacy against C. puteana wood decay in a soil-jar microcosm experiment, but no noticeable protection with antifungal compounds or the present treatments was found. However, a moderate effect by the TMP-T fraction from the in vitro assay was observed and the TMP-turpentine distillation residue showed a similar fungal inhibition effect to the most potent commercial treatment after 29 months in the field.
... Methods of multivariate statistics can evaluate chemical fingerprints to classify samples and predict their quality. Chemometric methods can be used for assessing data relating to the quality of herbal products [100]. Techniques include principal component analysis (PCA), local least square (LLS), linear discriminate analysis (LDA), spectral correlative chromatography (SCC), heuristicevolving latent projections (HELP), information theory (IT), and orthogonal projection analysis (OPA). ...
Thanks to omic disciplines and a systems biology approach, the study of essential oils and phytocomplexes has been lately rolling on a faster track. While metabolomic fingerprinting can provide an effective strategy to characterize essential oil contents, network pharmacology is revealing itself as an adequate, holistic platform to study the collective effects of herbal products and their multi-component and multi-target mediated mechanisms. Multivariate analysis can be applied to analyze the effects of essential oils, possibly overcoming the reductionist limits of bioactivity-guided fractionation and purification of single components. Thanks to the fast evolution of bioinformatics and database availability, disease-target networks relevant to a growing number of phytocomplexes are being developed. With the same potential actionability of pharmacogenomic data, phytogenomics could be performed based on relevant disease-target networks to inform and personalize phytocomplex therapeutic application.
... The LVO has been found to be effective against many species of bacteria, including antibiotic-resistant bacteria such as vancomycinresistant Enterococcus (VRE) and methicillin-resistant Staphylococcus aureus (MRSA) (Cavanagh and Wilkinson, 2002). The ability of LVO to disrupt the permeability of cell membrane structure, thus interrupting the chemiosmotic control is the most possible reason for its lethal action against bacteria (Miladinovic et al., 2012). ...
The antibacterial activity of lavender (Lavendular angustifolia) essential oil (LVO) was tested against five Gram-negative and nine Gram-positive pathogenic bacteria isolated from cultured olive flounder (Paralichthys olivaceus) in Korea. Disc diffusion assay, minimum bactericidal concentration (MBC) and minimum inhibitory concentration (MIC) tests showed that growth of both Gram-negative and Gram-positive bacteria were inhibited by LVO. The inhibition zone diameter (IZD) increased in proportion to the LVO concentration for all of the fish pathogenic bacteria and the maximum effect was found at 100% (V/V) concentration of LVO. Streptococcus iniae was most sensitive to LVO while Edwardsiella tarda was most resistant. LVO was bacteriostatic (MBC/MIC>4) for all strains of S. iniae and bactericidal (MBC/MIC=1-4) for rest of the isolates, except one isoate of E. tarda. The antibiogram pattern indicated that all the bacterial strains excluding three strains of S. iniae (S186, S530 and S131) showed resistance to one or more antibiotics. Since antibacterial activity of LVO was considerably effective against fish pathogenic bacteria, their use could be effectively used to treat bacterial infections in aquaculture.
... In addition, since the outcome of antimicrobial assays can be affected by many factors, including essential oil isolation method, as well as the type of microbes, volume of inoculum, growth phase, culture medium used, pH of the media and incubation time and temperature, comparison of published data is complicated (Burt, 2004). However, in line with recent investigations (Danh et al., 2012;Miladinović et al., 2012;Puškárová et al., 2017;Sienkiewicz et al., 2011), the present study greatly supported antimicrobial efficacy of L. angustifolia essential oil, demonstrating its broad antimicrobial capacity against a number of Gram-negative and Gram-positive bacteria as well as dermatophytes, yeasts and moulds. When compared with referent lavender oil, the essential oil of lavandin 'Budrovka' was mainly found to be more effective or at least to have the same inhibitory effect against those important clinical and food-borne pathogens as well as environmental microorganisms (Tables 2 and 3). ...
... En outre, en comparaison avec les antibiotiques de référence, si l'effet des HE testées reste modéré pour la majorité des concentrations utilisées, il faut noter que vis-à-vis de S. aureus, à partir du traitement « 15 µl », l'action inhibitrice de l'huile essentielle de Lavandula dentata dépasse l'effet de l'antibiotique de référence ; ces résultats corroborent avec ceux mentionnés par d'autres chercheurs (Imelouane et al., 2009),(Miladinovic et al., 2012Benabdelkader et al., 2011). En fin, il a été rapporté que l'huile volatile de Lavandula stoechas L. en provenance de Tunisie a une activité antibactérienne envers six espèces bactériennes parmi lesquelles Staphylococcus aureus est la plus sensible (Bouzouita et al., 2005). ...
The aim of the present work is to compare the chemical composition, antibacterial and antifungal activity of two spontaneous species of lavender "Lavandula stoechas L." and "Lavandula dentata L." in Morocco. A phytochemical screening was performed on the aerial part of invested plants. The qualitative variation was revealed in the secondary metabolites of the species studied. Subsequently, the dosage of the crude organic extracts showed that the polyphenol content was higher in the methanol fraction, with an important yield in L. dentata. Also, the essential oils of the aerial part, obtained by hydrodistillation gave higher yields in L. dentata than L. pedunculata. Finally, tests of the antibacterial and antifungal activity of the essential oils of the two species were performed on four strains of bacterial pathogens (Staphylococcus aureus "Gram+," and Escherichia coli; Klebsiella pneumoniae and Proteus mirabilis which are Gram-), and three phytopathogenic fungi : Rhizopus stolonifer, Aspergillus brasiliensis and Penicillium expansum, The results obtained showed that the essential oil of L. dentata showed a strong antibacterial activity against the studied strains, particularly against S. aureus. While the antifungal activity revealed that L. pedunculata has a remarkable antifungal power against the fungi tested in comparison with L. dentata.
... Since the composition of LO may be varies due to different origin, we examined the major contents of LO using GC-MS [35]. A total of 31 major constituents of the LO were identified and LI accounted for 37.96% as the main component and was similar to previous reports [36,37]. Based on these results, we further investigated the cognitive effect of LO and LI in the D-gal and AlCl 3 treated mice and its related mechanism. ...
Lavender essential oil (LO) is a traditional medicine used for the treatment of Alzheimer’s disease (AD). It was extracted from Lavandula angustifolia Mill. This study was designed to investigate the effects of lavender essential oil (LO) and its active component, linalool (LI), against cognitive impairment induced by D-galactose (D-gal) and AlCl 3 in mice and to explore the related mechanisms. Our results revealed that LO (100 mg/kg) or LI (100 mg/kg) significantly protected the cognitive impairments as assessed by the Morris water maze test and step-though test. The mechanisms study demonstrated that LO and LI significantly protected the decreased activity of superoxide dismutase (SOD), glutathione peroxidase (GPX), and protected the increased activity of acetylcholinesterase (AChE) and content of malondialdehyde (MDA). Besides, they protected the suppressed nuclear factor-erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) expression significantly. Moreover, the decreased expression of synapse plasticity-related proteins, calcium-calmodulin-dependent protein kinase II (CaMKII), p-CaMKII, brain-derived neurotrophic factor (BDNF), and TrkB in the hippocampus were increased with drug treatment. In conclusion, LO and its active component LI have protected the oxidative stress, activity of cholinergic function and expression of proteins of Nrf2/HO-1 pathway, and synaptic plasticity. It suggest that LO, especially LI, could be a potential agent for improving cognitive impairment in AD.
... Essential oils, the constituents extracted from plants or spices, have recently gained extensive popularity and scientific interests [6]. They have various bioactivities including antiviral, antiparasitic, antioxidant, and anticancer activities [7,8]. Additionally, these substances have a strong antimicrobial activity against human pathogenic microorganisms and been widely utilized as flavoring and preservation in food industry [9,10]. ...
Thymol (2-isopropyl-5-methylphenol) is a natural ingredient used as flavor or preservative agent in food products. The antibacterial mechanism of thymol against Grampositive, Staphylococcus aureus was investigated in thiswork. A total of 15 membrane fatty acids were identified in S. aureus cells by gas chromatography–mass
spectrometry. Exposure to thymol at low concentrations induced obvious alterations in membrane fatty acid composition, such as decreasing the proportion of branched 12-methyltetradecanoic acid and 14-methylhexadecanoic acid (from 22.4 and 17.3% to 7.9 and
10.3%, respectively). Membrane permeability assay and
morphological image showed that thymol at higher concentrations
disrupted S. aureus cell membrane integrity, which may decrease cell viability. Moreover, the interaction of thymol with genomic DNA was also investigated using multi-spectroscopic techniques, docking and atomic force microscopy. The results indicated that thymol bound to the minor groove of DNA with binding constant (Ka) value of
(1.22 ± 0.14) × 104 M−1, and this binding interaction induced a mild destabilization in the DNA secondary structure, and made DNA molecules to be aggregated.
... Essential oils, the constituents extracted from plants or spices, have recently gained extensive popularity and scientific interests [6]. They have various bioactivities including antiviral, antiparasitic, antioxidant, and anticancer activities [7,8]. Additionally, these substances have a strong antimicrobial activity against human pathogenic microorganisms and been widely utilized as flavoring and preservation in food industry [9,10]. ...
Thymol (2-isopropyl-5-methylphenol) is a natural ingredient used as flavor or preservative agent in food products. The antibacterial mechanism of thymol against Gram-positive, Staphylococcus aureus was investigated in this work. A total of 15 membrane fatty acids were identified in S. aureus cells by gas chromatography–mass spectrometry. Exposure to thymol at low concentrations induced obvious alterations in membrane fatty acid composition, such as decreasing the proportion of branched 12-methyltetradecanoic acid and 14-methylhexadecanoic acid (from 22.4 and 17.3% to 7.9 and 10.3%, respectively). Membrane permeability assay and morphological image showed that thymol at higher concentrations disrupted S. aureus cell membrane integrity, which may decrease cell viability. Moreover, the interaction of thymol with genomic DNA was also investigated using multi-spectroscopic techniques, docking and atomic force microscopy. The results indicated that thymol bound to the minor groove of DNA with binding constant (Ka) value of (1.22 ± 0.14) × 104 M−1, and this binding interaction induced a mild destabilization in the DNA secondary structure, and made DNA molecules to be aggregated. Graphical AbstractThymol exerts its antibacterial effect throught destruction of bacterial cell membrane and binding directly to genomic DNA
... Par ailleurs la partie aérienne de L. dentata dont la richesse en huiles essentielles est démontrée précédemment a une activité très efficace sur les bactéries Gram (+) et plus ou moins modérée sur les Gram (-) ; cette activité inhibitrice dépasse largement l'effet de l'antibiotique de référence à partir du volume 15 µl de l'huile essentielle pour S. aureus. Ces résultats corroborent ceux mentionnés par d'autres chercheurs, notamment Miladinovic et al. (2012) rapportant que les huiles essentielles de certaines lavandes manifestent une activité supérieure aux antibiotiques conventionnels envers S. aureus. Cependant, l'activité antibactérienne de l'huile essentielle de la lavande stoechade s'est avérée moins active par rapport à la lavande dentée contre les bactéries testées. ...
In the present work, the aim is to compare the chemical composition and antibacterial activity of two lavender Species "Lavandula stoechas L." and "Lavandula dentata L.", belonging to wild flora of Morocco. Thus, a phytochemical screening was performed on the aerial part of invested plants, and no qualitative difference was detected between the studied species. Indeed, both contain catechin and gallic tannins, flavonoids (anthocyanins, flavones and catechols), sterols and triterpenes, in addition to combined anthracene compounds (C-glycosides). Whereas, the dosage of crude aqueous extracts showed that the contents of secondary metabolites, such as polyphenols, flavonoids and total and condensed tannins were higher in L. dentata. Also, the essential oils of the aerial part, obtained by hydrodistillation gave higher yields in L. dentata than L. stoechas. Finally, antibacterial activity tests were performed on four strains of bacterial pathogens (Staphylococcus aureus "Gram+," and Escherichia coli; Klebsiella pneumoniae and Proteus mirabilis which are Gram -) with both essential oils and crude aqueous extracts. The results obtained showed that essential oils have a powerful effect, particularly that of L. dentata on S. aureus, with an inhibition diameter about 30 mm. The crude extracts showed moderate antibacterial activity against Gram - and had no effect on Gram +.
... Zistili, že na každú z húb môžu účinne pôsobiť iné zložky EO či zmesi týchto zložiek. Porovnaním antibakteriálnej aktivity EO z tymiánu (Thymus vulgaris), levandule (Lavandula angustifolia) a marulky obyčajnej (Calamintha nepeta) sa zaoberá štúdia MILADINOVIĆ et al. (2012). Antimikrobiálna aktivita EO líšiaca sa hlavnými zložkami (tymián -thymol, levanduľa -linaloon, marulka obyčajnápiperitone oxide) bola vyhodnotená pomocou analýzy hlavných komponentov (PCA). ...
The aim of this study was to prove the use of diluted vapours of essential oils (EO) to protect the bookish fond from the effects of microorganisms. The main aim was to show that the use of EO does not decrease the mechanical and optical properties of lignocellulosic materials. Samples from 5 lignocellulosic materials were exposed to the effect to 6 types of diluted vapours of EO for 30 and 60 days. Dilution of EO vapours was set to 1:9 pieces to clean air with relative humidity of 75%. Change in mechanical properties of samples was measured with deflection curve by tree point method (bending stiffness). Optical properties were evaluated according the changes in ISO brightness and calculation of colour difference ΔE*. The results of the measuring show that the use of EO vapours has insignificant influence on changing of mechanical properties of samples. Change of ISO brightness was minimal by all used OE vapours. Higher colour difference resulted only by one type of sample, the material of groundwood.
... It is obvious that the MIC/MBC concentrations of 1,8cineole were generally greater than those of the oil. Therefore it appears that while 1,8-cineole may be largely responsible for the antimicrobial activity associated with the oil, other minor constituents contribute[9]. Hendry et al.[10] reported similar results for the antimicrobial properties of crude eucalyptus oil and its main component 1,8-cineole. ...
The chemical composition and antibacterial activity of Nepeta nuda (Lamiaceae) essential oil were examined, as well as the association between it and standard antibiotics: tetracycline and streptomycin. The antibacterial activities of 1,8-cineole, the main constituent of N. nuda oil, individually and in combination with standard antibiotics were also determined. The interactions of the essential oil and 1,8-cineole with antibiotics toward five selected strains were evaluated using the microdilution checkerboard assay in combination with chemoinformatics methods. Oxygenated monoterpenes were the most abundant compound class in the oil (57.8%), with 1,8-cineole (46.0%) as the major compound. The essential oil exhibited in vitro antibacterial activity against all tested bacterial strains, but the activities were lower than those of the standard antibiotics. The combinations N. nuda oil-antibiotic and 1,8-cineole-antibiotic produced a predominantly antagonistic interactions. Chemoinformatics survey confirms the antagonistic interactions as a consequence of membrane potential/proton motive force dissipation. These data indicate cytochrome c oxidase as a target for 1.8-cineole toxicity action mechanisms.
... In addition, the study of plant extracts can help in the designing of modern herbal medicinal products. It is important to note that the synergistic, additive or potentiated effects shown by the plant extract, frequently observed in the study of natural products, usually exceed the effects of single compounds, or mixtures of them at equivalent concentrations (24)(25)(26). ...
In this paper we have studied seasonal changes in metal and antioxidant contents of Salvia officinalis L. (sage) from Sićevo gorge Nature Park. Collected leaves were analyzed for iron, copper, zinc and manganese concentrations, quantities of malonyldialdehyde, superoxide and hydroxyl radicals, as well as the activities of antioxidant enzymes (superoxide dismutase, catalase, guaiacol peroxidase). Also, the content of reduced glutathione, caro-tenoids, total flavonoids, soluble proteins, chlorophylls a and b was determined. The examined plant accumulates sufficient content of researched elements during vegetation, except for the iron in the seed-forming stage. A significant effect of growth stage on super-oxide and hydroxyl radicals' accumulation was observed, but there were no significant differences in lipid peroxidation levels during vegetation. Antioxidant enzymes in the low and middle range of activities in leaves of S. officinalis were correlated with protein, chlorophyll a and b contents, except for SOD. On the other hand, contents of non-enzymatic antioxidants varied greatly between different stages of growth, as well as the contents of protected molecules, with which they were positively correlated. Results from the present study suggest that antioxidant defense system of S. officinalis functions fully and protects target molecules of reactive oxygen species. The leaves of sage from Sićevo gorge Nature Park should be considered as an important source of iron, cooper, zinc, manganese and dietary antioxidants. Acta Medica Medianae 2015;54(1):27-33.
... Besides the contents of ginsenosides, the compositions of active components are very important for the bioactivity of ginseng. The two types of ginsenosides play different roles in some bioactivities, and their compositional differences among ginsenosides are a key factor for this [34][35][36]. The optimal combination may provide the strongest bioactivities, that is, the best composition-activity relationship. ...
The aim of this study was to systematically evaluate the effect of the cultivation year on the quality of different ginseng tissues. Qualitative and quantitative analyses of ginsenosides were conducted using a UPLC-UV-MS method. Eight main ginsenosides in three tissues (leaf, rhizome and main root) and four parts (periderm, phloem, cambium and xylem) of ginseng aged from 1 to 13 years were determined using a UPLC-PDA method. Additionally, the antioxidant capacities of ginseng leaves were analyzed by the DPPH, ABTS and HRSA methods. It was found that the contents of ginsenosides increased with cultivation years, causing a sequential content change of ginsenosides in an organ-specific manner: leaf > rhizome > main root. The ratio between protopanaxatriol (PPT, Rg1, Re and RF) and protopanaxadiol (PPD, Rb1, Rb2, RC and Rd) in the main root remained stable (about 1.0), while it increased in leaf from 1.37 to 3.14 and decreased in the rhizome from 0.99 to 0.72. The amount of ginsenosides accumulated in the periderm was 45.48 mg/g, which was more than twice as high compared with the other three parts. Furthermore, the antioxidant activities of ginseng leaves were measured as Trolox equivalents, showing that antioxidant activity increased along with time of cultivation. The results show that the best harvest time for shizhu ginseng is the fifth year of cultivation, and the root and rhizome could be used together within seven planting years for their similar PPT/PPD level. Besides, the quality of the ginseng products would be enhanced with the periderm. The ginseng leaf is rich in ginsenosides and has potential application for its antioxidant capacity.
... Among all Thymus species from Balkan Peninsula, T. vulgaris has been the most studied concerning biological activity of its essential oil (Bozin et al. 2006;Hoferl et al. 2009;Levic et al. 2011;Ivanovic et al. 2012;Lagouri et al. 2011;Lakis et al. 2012;Isopencu and Ferdes 2012). Most of the papers dealing with this subject compared essential oil of Thyme with essential oils of other medicinal aromatic plants, such as Sage, Basil, and Rosemary, where T. vulgaris found to be the most effective in bacterial and fungal growth inhibition (Gyorgy 2010; Ivanovic et al. 2012;Miladinovic et al. 2012;Daferera et al. 2000;Zivkovic et al. 2013). Thymus vulgaris with high content of thymol (47.9 %) revealed high antimicrobial activity against 10 bacteria (Bozin et al. 2006), as well as T. longicaulis with high content of carvacrol (60.8 %), while the same species with p-cymene (Klaric et al. 2007) and geraniol chemotype (Chorianopoulo et al. 2004) showed lower activity but still comparable with antibiotics that are used as control probes. ...
Export Date: 18 October 2014, Article in Press
... Thus, a search for new and more sustainable antibiotics is a necessity. Many studies have shown significant antibacterial activity of essential oils against a wide range of resistant microbial strains (de Mendonc a Rocha et al. 2012;Miladinović et al. 2012;Ilić et al. 2014). To enhance the efficacy of antibacterial drugs and to reduce the required concentration, their combined use with essential oils is one of the promising strategies (Miladinović et al. 2013). ...
The chemical composition and antibacterial activity of Peucedanum officinale L. (Apiaceae) essential oil were examined, as well as the association between it and antibiotics: tetracycline, streptomycin and chloramphenicol. The interactions of the essential oil with antibiotics were evaluated using the microdilution checkerboard assay. Monoterpene hydrocarbons, with α-phellandrene as the dominant constituent, were the most abundant compound class of the essential oil of P. officinale. The researched essential oil exhibited slight antibacterial activity against the tested bacterial strains In vitro. On the contrary, essential oil of P. officinale possesses a great synergistic potential with chloramphenicol and tetracycline. Their combinations reduced the minimum effective dose of the antibiotic and, consequently, minimised its adverse side effects. In addition, investigated interactions are especially successful against Gram-negative bacteria, the pharmacological treatment of which is very difficult nowadays.
... Among all Thymus species from Balkan Peninsula, T. vulgaris has been the most studied concerning biological activity of its essential oil (Bozin et al. 2006;Hoferl et al. 2009;Levic et al. 2011;Ivanovic et al. 2012;Lagouri et al. 2011;Lakis et al. 2012;Isopencu and Ferdes 2012). Most of the papers dealing with this subject compared essential oil of Thyme with essential oils of other medicinal aromatic plants, such as Sage, Basil, and Rosemary, where T. vulgaris found to be the most effective in bacterial and fungal growth inhibition (Gyorgy 2010; Ivanovic et al. 2012;Miladinovic et al. 2012;Daferera et al. 2000;Zivkovic et al. 2013). Thymus vulgaris with high content of thymol (47.9 %) revealed high antimicrobial activity against 10 bacteria (Bozin et al. 2006), as well as T. longicaulis with high content of carvacrol (60.8 %), while the same species with p-cymene (Klaric et al. 2007) and geraniol chemotype (Chorianopoulo et al. 2004) showed lower activity but still comparable with antibiotics that are used as control probes. ...
Thymus L. is one of the most important and polymorphic genera of the Lamiaceae family, comprises ca. 250 species distributed across the Eurasian continent, North and East Africa, and southern Greenland, but the great majority of the indigenous species is found in the area that surrounds the Mediterranean region. Thymus species can potentially be used as the medicinal or aromatic herbs in the pharmaceutical and food industries. The essential oils of Thymus species are characterized by a high chemical variability due to different intrinsic (genetic variation) and extrinsic (ecological and environmental aspects) factors. Despite broad scientific interest in the biology, taxonomy, chemotypes, and related biological activity of secondary metabolites of Thymus species, there is a general lack of information regarding this genus from Balkan. The aim of the present review was to comprise the literature in order to document essential oil constituents that characterize different Thymus species from Balkan Peninsula. Essential oil composition of 45 Thymus taxa from ten countries was summarized. In addition, it discusses the reported biological activities of Thymus species, with particular focus on their antimicrobial and antioxidant properties. Cultivation of rare species, monitoring, and standardization of their essential oils, as well as direct studies on cellular and animal models are needed to assess whole spectrum of biological properties of essential oils of Thymus species.
... To eliminate any kind of subjective analysis, interpretations and discussions of the results, presented by tables and/or graphics, chemometric methods: principal component analysis (PCA) and hierarchical cluster analysis (HCA) were employed. Furthermore, the use of chemometric methods allows the maximum number of experimental results to be obtained and moreover enables the detection of connections, similarities and differences among variables in the researched experimental system [10]. ...
The chemical composition and antibacterial activity were examined of Libanotis montana Crantz subsp. leiocarpa (Heuff.) Soó. (Apiaceae) essential oil. Gas chromatography and gas chromatography/mass spectrometry were used to analyze the chemical composition of the oil. The antibacterial activity was investigated by the broth microdilution method against thirteen bacterial strains. The interactions of the essential oil and three standard antibiotics: tetracycline, streptomycin and chloramphenicol toward five selected strains were evaluated using the microdilution checkerboard assay in combination with chemometric methods: principal components analysis and hierarchical cluster analysis. Sesquiterpene hydrocarbons were the most abundant compound class in the oil (67.2%), with β-elemene (40.4%) as the major compound. The essential oil exhibited slight antibacterial activity against the tested bacterial strains in vitro, but the combinations L. montana oil-chloramphenicol and L. montana oil-tetracycline exhibited mostly either synergistic or additive interactions. These combinations reduced the minimum effective dose of the antibiotics and, consequently, minimized their adverse side effects. In contrast, the association of L. montana essential oil and streptomycin was characterized by strong antagonistic interactions against Escherichia coli ATCC 25922. In the PCA and HCA analyses, streptomycin stood out and formed a separate group.
... Multivariate analysis (principal component analysis -PCA and partial least squares -PLS) has been applied to the classification of preparations from natural sources, e.g. samples of cannabis batches from different sources (Hazekamp and Fischedick, 2012), essential oils with antibacterial activity (Miladinović et al., 2012) and erythropoietin preparations (Taichrib et al., 2012). ...
Teicoplanin is an antibiotic made by fermentation in which a glycopeptide core is substituted by different fatty acids. The chemical structure and proportion of the various components are strictly dependent on the production process (Actinoplanes sp strain, cell culture conditions and downstream process). Thus, a relevant variability can be introduced from different manufacturers. Interchangeability or substitution among the originator and the generic products of teicoplanin injections is under debate with respect to pharmaceutical similarity. In fact, depending on the manufacturer, the six major components of teicoplanin show different quantitative distributions compared to that of the originator. The European Pharmacopoeia fixed an undifferentiated upper limit for the component content. A statistical approach is required for comparing complex products. In this paper the use of Principal Component Analysis (PCA) as a tool for identifying the pharmaceutical equivalence among teicoplanin products from different sources was explored. The results obtained show that PCA can distinguish the differing origin of this biological drug.
... Metabolites isolated from C. nepeta, and especially its volatile fraction, have been found to display anti-inflammatory [6,7], antibacterial, antifungal [5,8,9], and antioxidant [6,7,10] properties. No reports on the possible phytotoxic activity of the secondary metabolites of the plant have been reported. ...
The chemical composition of the essential oil from aerial parts of Calamintha nepeta (L.) Savi, collected in the Campania Region, was obtained by hydrodistillation and analyzed by GC and GC-MS. In all, 42 compounds were identified. The oil was characterized by a prevalence of the sesquiterpenic fraction (80.8%). The main components were 1,10-di-epi-cubenol (18.5%), allo-aromadendrene epoxide (11.4%) and cadalene (5.7%). The essential oil was evaluated for its in vitro potential phytotoxic activity against germination and initial radical growth of Raphanus sativus L., Lepidium sativum L., Sinapis arvensis L., Triticum durum L. and Phalaris canariensis L. seeds. The essential oil showed no antioxidant activity.
The significance of minor constituents of essential oils (EOs) for antibacterial activity by chemometric methods principal component analysis (PCA) and hierarchical clustering analysis (HCA) was researched. In this study, the antibacterial activity of six EOs from Achillea and Artemisia species was evaluated on nine laboratory control bacterial strains. Gas Chromatographic-Mass Spectrometric (GC/MS) data showed that these samples have similar chemical compositions, with highest content of oxygenated monoterpenes and lowest content of oxygenated sesquiterpenes and sesquiterpenes hydrocarbons. The strongest clustering is observed for Achillea millefolium and Achillea crithmifolia EOs. In PCA analysis, these two EOs are located at the considerable distance away from all of the other samples of EOs, indicating that their composition and activity differs significantly from the other samples. All bacteria for assessment of antimicrobial activity are grouped to the left side of the plot, located diametrically opposite to group I. This unique location can be pointed out as a reason for the lowest activity against bacteria, suggesting that the dominant EO components may not determine antibacterial activity. These findings were suggesting that the minor compounds (oxygenated sesquiterpenes and sesquiterpenes hydrocarbons) or a combination thereof were possibly responsible for the complete antibacterial activity of EOs.
Background:
The commercialization of essential oils has expanded their presence in the United States, and emerging studies demonstrate that they may have a place in Western medicine. One oil with a significant body of evidence is lavender essential oil, which may have benefits in wound healing.
Objectives:
This review aims to present the scientific literature on therapeutic lavender essential oil with the goal of expanding the current repertoire of cost-effective wound healing options available to physicians and patients.
Methods:
A review was conducted according to PRISMA guidelines in PubMed, Cochrane Library, and Embase from June 2018 through March 2019 to identify articles related to lavender essential oil in the context of wound healing.
Results:
This search yielded 36 unique studies, 20 of which remained after screening. This review utilizes human clinical trials (n = 7), animal trials (n = 5), in vitro studies (n = 2), and previously conducted reviews (n = 6). Overall, these studies demonstrated a faster rate of wound healing, increased expression of collagen, and enhanced activity of proteins involved in the tissue remodeling process in wounds treated with lavender essential oil.
Conclusions:
The current body of literature suggests a potential therapeutic benefit of lavender essential oil in wound healing. However, standardization of the chemical composition and additional high-quality human clinical trials are needed to further evaluate the safety and efficacy of lavender essential oil in clinical practice.
Veratrum plant contains a family of compounds called steroidal alkaloids which have been previously reported to cause DNA damage and blood pressure decrease in vivo. In this study, the antihypertensive effects and DNA damage in brain cells of 12 steroidal alkaloids separated from Veratrum plant were all evaluated to develop a relationship among chemical structure, antihypertensive activity and neurotoxicity by utilization of chemical principal component analysis (PCA) and hierarchical cluster analysis (HCA). Twelve steroidal alkaloids markedly reduced high blood pressure of hypertensive mice and also similarly induced varying degrees of DNA single‐strand breaks in mouse cerebellum and cerebral cortex after oral administration. On the basis of the PCA and HCA results, it was suggested that the 3‐carboxylic esters and benzene group play a core role in the DNA damage of brain cells, while more hydroxy groups in the A‐ring and B‐ring structure of jervine‐type alkaloid led to stronger antihypertensive activity. The primary structure, activity and neurotoxicity relationship were discussed briefly.
The aim of present chapter is to gather the information about chemical composition, biological activities and possible applications of essential oils from seven different species of Genus Salvia growing in Bulgaria (S. officinalis L., S. sclarea L., S. tomentosa Mill, S. scabiosifolia Lam., S. ringens Sibth. et Sm., S. amplexicaulis Lam. and S. aethiopis L.). The chapter is focused on the variations in chemical composition of the essential oil caused by different climate and agro-industrial factors. Different forms of bioactivities of essential oils from Salvia spp. growing in Bulgaria and their possible applications are also discussed.
Lavandula species are one of the most useful aromatic and medicinal plants with a great economic value for pharmaceutical, food and flavor industries, cosmetics, perfumery, and aromatherapy. The pleasant fragrance, physiological effects, and commercial significance are due to the their essential oils, with a highly variable composition dependent on the genetic, environmental and processing factors. This paper provides a systematic view on the chemistry of lavender essential oils especially considering the studies in the last 15 years. The review presents the characteristic chemical constituents and chemotypes of seventeen Lavandula species. The intra- and interspecific variability is primarily discussed dependent on the geographic area, onto-and morphogenetic factors, and extraction methods. In addition, biosynthesis of lavender terpenes is presented.
In the present study, the chemical composition and antibacterial activity of Peucedanum longifolium Waldst. & Kit. (Apiaceae) essential oil were examined, as well as the association between it and standard antibiotics. Gas chromatography and gas chromatography/mass spectrometry were used to analyze the chemical composition of the oil. The antibacterial activity of the oil was investigated by the broth microdilution method against thirteen bacterial strains. The interactions of the essential oil with three conventional antibiotics: tetracycline, streptomycin and chloramphenicol toward five selected bacterial strains were evaluated using the microdilution checkerboard assay. Monoterpene hydrocarbons (61.60%), with myrcene (15.88%) as the dominant constituent, were the most abundant compound class of the essential oil of P. longifolium from Serbia. The researched essential oil exhibited slight antibacterial activity against the tested bacterial strains in vitro. On the contrary, essential oil of P. longifolium posseses significant synergistic potential in combination with streptomycin and chloramphenicol (FIC indices in the range 0.21–0.87). Their combinations reduced the minimum effective dose of the antibiotic and, consequently, minimized its adverse side effects. In addition, investigated interactions are especially successful against Gram-negative bacteria, the pharmacological treatment of which is very difficult nowadays. These results indicate a method to enhance the efficacy of antibacterial drugs, especially against resistant bacterial strains.
The chemical composition and antibacterial activity of Thymus glabrescens Willd. (thyme) essential oil were examined, as well as its association with tetracycline. The antibacterial activities of geraniol and thymol, the main constituents of T. glabrescens oil, were also determined. Gas chromatography and gas chromatography/mass spectrometry were used to analyze the chemical composition of the oil. The antibacterial activities of the oil, geraniol, and thymol were investigated by the broth microdilution method. The interactions of the essential oil, geraniol, and thymol with tetracycline, toward five selected strains, were evaluated using the microdilution checkerboard assay. Oxygenated monoterpenes were the most abundant compound class in the oil (57.14%), with geraniol (22.33%) as the major compound. The essential oil exhibited in vitro antibacterial activity against all tested bacterial strains. The combinations, essential oil-tetracycline and thymol-tetracycline, produced synergistic interaction to a greater extent compared with geraniol-tetracycline association. All synergistic combinations reduced the minimum effective dose of the antibiotic and, consequently, minimized its adverse side effects.
Antimicrobial activities of thyme essential oil against selected microorganisms, including Fusarium sp., Armillaria mellea, Bacillus cereus, Staphylococcus aureus, Buttiauxella sp., Klebsiella pneumoniae, Escherichia coli K-12, AmpC-producing E. coli Z, ESBL-producing E. coli strain of KM clonal group ST131, and E. coli 1138 were evaluated. The antimicrobial efficacy of thyme essential oil was determined using agar well diffusion assays. The growth of all tested bacteria was inhibited at thyme essential oil fractions higher than 1 %, while a fraction of 10 % was needed to inhibit the growth of fungi. We demonstrate that thyme essential oil has a promising activity against food spoilage bacteria, and also against multiresistant AmpC-producing and ESBL-producing bacterial strains isolated from food, which have recently been recognised as public health concerns. On the basis of our data, the thyme essential oil has a potential for use as a growth inhibitor of multidrug-resistant bacteria, and food spoilage and pathogenic bacteria and fungi, to replace commonly used semi-synthetic antimicrobial products.
Clostridium perfringens is the causative agent of necrotic enteritis leading to significant losses in the poultry industry. Dichloromethane and n-hexane extracts of aerial parts of Artemisia annua (Asteraceae) exhibited activity against C. perfringens with
minimum inhibitory concentrations (MIC) of 185 and 270 μg/mL, respectively. Bioassay-guided fractionation of the extracts gave several active fractions (MIC between 75 and 600 μg/mL). Investigations of the most active fractions resulted in the isolation and characterization of the polyacetylene
ponticaepoxide (MIC between 100 and 200 μg/mL) and (+)-threo-(5E)-trideca-1,5-dien-7,9,11-triyne-3,4-diol (MIC between 400 and 800 μg/mL), the flavonols chrysosplenol D (MIC between 200 and 400 μg/mL) and casticin (slight inhibition at 800 μg/mL), and 2,4-dihydroxy-6-methoxyacetophenone
(slight inhibition at 800 μg/mL). Also, the coumarin scopoletin and the sesquiterpene lactone artemisinin were isolated from active fractions but showed no inhibition of C. perfringens growth at 800 and 2000 μg/mL, respectively. Fractions containing essential oil components with
camphor constituting >60% did not show inhibition of C. perfringens up to 1600 μg/mL. Extracts and some active fractions showed higher antibacterial effect than individual bioactive compounds, suggesting that synergistic effects may underlie the observed antibacterial effect.
The present study adds new valuable information on the antibacterial effect of A. annua against C. perfringens.
The aim of this study was to research the seasonal changes of antioxidant enzyme activity and total antioxidant capacity in leaves of Astragalus onobrychis L. subsp. chlorocarpus (Griseb.) S. Kozuharov et D.K. Pavlova. Leaves of A. onobrychis were collected during the different stages of growth and analyzed for antioxidant enzyme activity: superoxide dismutase, catalase, guaiacol peroxidase, glutathione peroxidase. Quantities of malonyldialdehyde, superoxide radicals, and hydroxyl radicals were measured as well as the content of soluble proteins. Furthermore, total antioxidant capacity was determined by the inhibition of chemiluminescence activity of blood phagocytes by leaf extracts. Stages of vegetation significantly affected the accumulation of superoxide radicals, but there were no significant differences in hydroxyl radical quantity and lipid peroxidation levels during vegetation. Soluble proteins vary greatly between different stages of growth. Seasonal changes were found to have an effect on enzymatic activities. During the spring season, guaiacol peroxidase showed the highest levels. Catalase and glutathione peroxidase increased their activities in summer, while, during the autumn season, superoxide dismutase showed maximum activity. On the basis of chemiluminescence assay, it can be concluded that leaf extract of A. onobrychis possesses a significant antioxidant capacity thus protecting plants during environmental stress.
A 57-year-old woman named C. B. began experiencing abdominal pain and bloating. She presented to her primary physician with these symptoms, and her physician palpated an adenexal mass on pelvic examination. That prompted a computed tomography (CT) scan of the abdomen and pelvis, which demonstrated omental thickening as well as a mildly enlarged left ovary. After initial consultation with a gynecologic oncologist, C. B. was taken to surgery and a total abdominal hysterectomy bilateral salpingo-oophorectomy omentectomy partial bowel resection, and pelvic and periaortic lymph node dissection were performed. C. B. was diagnosed with stage IV ovarian cancer involving the omentum, pelvic lymph nodes, and bowel wall and was subsequently referred for postoperative chemotherapy.
Many cyclic hydrocarbons, e.g. aromatics, cycloalkanes, and terpenes, are toxic to microorganisms. The primary site of the toxic action is probably the cytoplasmic membrane, but the mechanism of the toxicity is still poorly understood. The effects of cyclic hydrocarbons were studied in liposomes prepared from Escherichia coli phospholipids. The membrane-buffer partition coefficients of the cyclic hydrocarbons revealed that these lipophilic compounds preferentially reside in the membrane. The partition coefficients closely correlated with the partition coefficients of these compounds in a standard octanol-water system. The accumulation of hydro carbon molecules resulted in swelling of the membrane bilayer, as assessed by the release of fluorescence self-quenching of fluorescent fatty acid and phospholipid analogs. Parallel to the expansion of the membrane, an increase in membrane fluidity was observed. These effects on the integrity of the membrane caused an increased passive flux of protons and carboxyfluorescein. In cytochrome c oxidase containing proteoliposomes, both components of the proton motive force, the pH gradient and the electrical potential, were dissipated with increasing concentrations of cyclic hydrocarbons. The dissipating effect was primarily the result of an increased permeability of the membrane for protons (ions). At higher concentrations, cytochrome c oxidase was also inactivated. The effective concentrations of the different cyclic hydrocarbons correlated with their partition coefficients between the membrane and aqueous phase. The impairment of microbial activity by the cyclic hydrocarbons most likely results from hydrophobic interaction with the membrane, which affects the functioning of the membrane and membrane-embedded proteins.
Adams, R. P. 2007. Identification of essential oil components by gas chromatography/ mass spectrometry, 4th Edition. Allured Publ., Carol Stream, IL
Is out of print, but you can obtain a free pdf of it at
www.juniperus.org
The essential oil from flowering Thyme (Thymis vulgaris L.) an aromatic member of the Lamiaceae family, from Morocco, obtained by hydrodistillation, was analysed by GC/FID and GC/MS. The constituents were identified by their mass spectra and Kovats' indices. Forty three compounds consisting 97.85% of the total components were identified from the oil obtained with 1% yield. Among those, camphor (38.54%), camphene (17.19%), α-pinene (9.35%), 1, 8-cineole (5.44%), borneol (4.91%) and β-pinene (3.90%) were the major oil components. Essential oil of Thyme was evaluated for its antibacterial activities against six Gram-positive and Gram negative pathogenic bacteria: Staphylococcus aureus, S. epidermidis, Streptococcus sp., Pantoa sp. and Escherichia coli.
Lavender essential oil is popular as a complementary medicine in its own right and as an additive to many over the counter complementary medicine and cosmetic products¹⁻³. Indeed, products derived from the popular garden herb Lavender (Lavandula spp.) have been used for centuries as a therapeutic agent, with the more ’recent’ addition, the essential oils derived from these plants, being widely used as an antibacterial in World War I1,4. The oil is traditionally believed to have sedative, carminative, anti-depressive and antiinflammatory properties, in addition to its recognised antimicrobial effects.
Many of the activities attributed to lavender oil have not, however, been substantiated in the scientific literature. This is further complicated by the fact that the majority of research into lavender essential oils has been based on oil derived from English lavender (Lavandula angustifolia), with little or no differentiation being made between this and other lavender essential oils. The therapeutic potential of essential oils produced from other varieties, such as L. x intermedia (lavandin), L. stoechas (French lavender) and L. x allardii, have largely been ignored. Although the ethnobotanical uses and major chemical constituents are similar between various lavenders, some differences do occur in both oil composition and in the reported therapeutic uses for different species3,5. The significant scientific interest in recent years into the validity/veracity of the traditional beliefs surrounding lavender oil and their scientific basis, if any, was recently reviewed by Cavanagh & Wilkinson³. In this paper we provide an overview of the use of lavender oil in infectious disease and an update on recent research on alternative uses of lavender oil.
The essential oil content in the inflorescence of lavender (Lavandula angustifolia Mill.) cultivated in the mid hills of Uttarakhand was found to be 2.8 % based on the fresh weight. The oil was analysed by capillary GC and GC– MS. Thirty seven constituents, representing 97.81 % of the oil were identified. The major components of the oil were linalyl acetate (47.56 %), linalool (28.06 %), lavandulyl acetate (4.34 %) and α-terpineol (3.75 %). The quality of lavender oil produced in India was found to be comparable to that produced in Hungary, France, China, Bulgaria, Russia and the USA.
The inhibitory effects of essential oils including clove, laven-der and geranium extracted from Eugenia caryophyllata, Lavandula officinalis and Pelargonium graveolens on multi-drug resistant isolates of Pseudomonas aeruginosa were investigated. The main constituents of clove, lavander and geranium oil were eugenol (80-90%), 1,8-cineol (13%) and citronellol (45%) respectively. Clove had the most effective essential oil against P. aeruginosa. A combination consisting of clove, lavender and geranium oils at a ratio of 3:1:1 showed the most inhibitory effect (32-64 pg/ml) and strong synergy with gentamicin. The essential oils from clove, lavender and geranium exhibited bactericidal activity against multi-drug resistant strains of P. aeruginosa and may be alternatives compounds against these strains in the future.
Free fatty acids (FFAs), which are considered to be closely related with type 2 diabetes mellitus (T2DM), are not only the
main energy source as nutrients, but also signaling molecules in insulin secretion. In this study, gas chromatography–mass
spectrometry (GC–MS) coupled with two chemometric resolution methods, heuristic evolving latent projections (HELP) and selective
ion analysis (SIA), was successfully applied to investigate plasma FFAs profiling of T2DM. Totally, twenty-three FFAs were
identified and quantified. The results showed that HELP and SIA methods could be used to effectively handle overlapping peaks
of GC–MS data and hence improve the qualitative and quantitative accuracy. Furthermore, a newly proposed competitive adaptive
reweighted sampling (CARS) method coupled with partial least squares linear discriminant analysis (PLS-LDA) was introduced
to seek the potential biomarkers. Finally, three fatty acids, oleic acid (OLA C18:1n-9), α-linolenic acid (ALA C18:3n-3),
and eicosapentaenoic acid (EPA C20:5n-3), were identified as the potential biomarkers of T2DM for their powerful discriminant
ability of T2DM patients from healthy controls. The study indicated that GC–MS combining with chemometric methods was a useful
strategy to analyze metabolites and further screen the potential biomarkers of T2DM.
KeywordsFree fatty acids (FFAs)-Type 2 diabetes mellitus (T2DM)-Heuristic evolving latent projections (HELP)-Selective ion analysis (SIA)-Competitive adaptive reweighted sampling (CARS)-Biomarkers
Hydro-distilled essential oil from Satureja biflora (Lamiaceae) growing in Kenya was analysed by gas chromatography mass spectrometry (GC-MS) and also evaluated for antimicrobial activity. Twenty two compounds which constitute 99.29 % of the total oil were identified. The oil was dominated by monoterpenes, which accounted for 62.02 % of the oil. This monoterpene fraction was characterized by a high percentage of linalool (50.60 %) such that this Satureja species can be classified as the linalool chemotype. The other major monoterpenes were α-terpineol (2.80 %), β-ocimene (2.25 %), β-pinene (1.96 %) and cis-linalool oxide (1.91 %). Sesquiterpenes present in fairly good amounts are germacrene D (10.63 %), α-cadinol (4.53 %), β-bourbonene (2.33 %), δ-cadinene (2.19 %), τ-cadinol (2.17 %), endo-1-bourbonanol (2.14 %) and β-caryophyllene (1.98 %). Aliphatic alcohols and acids accounted for 7.23 % of the oil, of which the major one was linoleic acid (4.48 %). The oil was screened for antimicrobial activity against both gram-positive (Staphylococcus aureus, Bacillus ssp. ) and gram-negative (Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, Klebsiella pheumoniae, Proteus mirabilis) bacteria and a pathogenic fungus (Candida albicans). To the best of our knowledge nothing concerning the chemical composition and biological activity of the essential oil of S. biflora has been reported.
The chemical composition and antibacterial activity of essential oils from 10 commonly consumed herbs: Citrus aurantium, C. limon, Lavandula angustifolia, Matricaria chamomilla, Mentha piperita, M. spicata, Ocimum basilicum, Origanum vulgare, Thymus vulgaris and Salvia officinalis have been determined. The antibacterial activity of these oils and their main components; i.e. camphor, carvacrol, 1,8-cineole, linalool, linalyl acetate, limonene, menthol, a-pinene, b-pinene, and thymol were assayed against the human pathogenic bacteria Bacillus subtilis, Enterobacter cloacae, Escherichia coli O157:H7, Micrococcus flavus, Proteus mirabilis, Pseudomonas aeruginosa, Salmonella enteritidis, S. epidermidis, S. typhimurium, and Staphylococcus aureus. The highest and broadest activity was shown by O. vulgare oil. Carvacrol had the highest antibacterial activity among the tested components.
The essential oils of the Osmanthus fragrans tea (OFT), Osmanthus fragrans (OF) and green tea (GT) had been extracted by steam distillation and analyzed by gas chromatography-mass spectrometry (GC-MS) with the help of heuristic evolving latent projections (HELP), an effective chemometric resolution method (CRM). The overlapping peak clusters were resolved into pure chromatograms and pure mass spectra with HELP. The qualitative analysis was performed by similarity searches in the National Institute of Standards and Technology (NIST) mass spectra database with the obtained pure mass spectrum of each component. Identification of some compounds was also assisted by comparison of temperature-programmed retention indices (PTRI) with authentic standards included in our own laboratory database under construction. The quantitative results were obtained by overall volume integration (OVI) method. A total of 67, 73 and 53 components in essential oils of the OFT, OF and GT were identified, accounting for 90.83%, 93.65% and 89.97% total contents of the essential oil of OFT, OF and GT, respectively.
The essential oil content in the inflorescence of lavender (Lavandula angustifolia Mill.) cultivated in the mid hills of Uttarakhand was found to be 2.8 % based on the fresh weight. The oil was analysed by capillary GC and GC–MS. Thirty seven constituents, representing 97.81 % of the oil were identified. The major components of the oil were linalyl acetate (47.56 %), linalool (28.06 %), lavandulyl acetate (4.34 %) and α-terpineol (3.75 %). The quality of lavender oil produced in India was found to be comparable to that produced in Hungary, France, China, Bulgaria, Russia and the USA.
The essential oil of Melaleuca alternifolia (tea tree) exhibits broad-spectrum antimicrobial activity. Its mode of action against the Gram-negative bacterium Escherichia coli AG100, the Gram-positive bacterium Staphylococcus aureus NCTC 8325, and the yeast Candida albicans has been investigated using a range of methods. We report that exposing these organisms to minimum inhibitory and minimum bactericidal/fungicidal concentrations of tea tree oil inhibited respiration and increased the permeability of bacterial cytoplasmic and yeast plasma membranes as indicated by uptake of propidium iodide. In the case of E. coli and Staph. aureus, tea tree oil also caused potassium ion leakage. Differences in the susceptibility of the test organisms to tea tree oil were also observed and these are interpreted in terms of variations in the rate of monoterpene penetration through cell wall and cell membrane structures. The ability of tea tree oil to disrupt the permeability barrier of cell membrane structures and the accompanying loss of chemiosmotic control is the most likely source of its lethal action at minimum inhibitory levels.
The natural antimicrobial compound carvacrol shows a high preference for hydrophobic phases. The partition coefficients of
carvacrol in both octanol-water and liposome-buffer phases were determined (3.64 and 3.26, respectively). Addition of carvacrol
to a liposomal suspension resulted in an expansion of the liposomal membrane. Maximum expansion was observed after the addition
of 0.50 μmol of carvacrol/mg of l-α-phosphatidylethanolamine. Cymene, a biological precursor of carvacrol which lacks a hydroxyl group, was found to have a
higher preference for liposomal membranes, thereby causing more expansion. The effect of cymene on the membrane potential
was less pronounced than the effect of carvacrol. The pH gradient and ATP pools were not affected by cymene. Measurement of
the antimicrobial activities of compounds similar to carvacrol (e.g., thymol, cymene, menthol, and carvacrol methyl ester)
showed that the hydroxyl group of this compound and the presence of a system of delocalized electrons are important for the
antimicrobial activity of carvacrol. Based on this study, we hypothesize that carvacrol destabilizes the cytoplasmic membrane
and, in addition, acts as a proton exchanger, thereby reducing the pH gradient across the cytoplasmic membrane. The resulting
collapse of the proton motive force and depletion of the ATP pool eventually lead to cell death.
The essential oils (EO) of Mentha suaveolens, a wild Labiatae, which grows in several regions in Morocco, were characterized and their antimicrobial activity assessed. The main aromatic constituents of this plant, as characterized by IR, NMR and MS studies, were pulegone, piperitenone oxide (PEO) and piperitone oxide (PO) occurring in different amounts depending on the subspecies. These constituents as well as a series of other aromatic products such as carvone, limonene and menthone, were tested for their antimicrobial activity against 19 bacteria including Gram-positive and Gram-negative and against three fungi, using solid phase and microtitration assays. Pulegone-rich essential oil inhibited efficiently all the micro-organisms tested with MICs ranging between 0.69 and 2.77 ppm. Among the components from Mentha suaveolens EO, pulegone was the most effective against the tested microorganisms, followed by PEO and PO. The structure-activity relationship is discussed on the basis of the activity of the other aromatic derivatives tested such as carvone, limonene, menthone and the profile of the essential oils of Mentha suaveolens was compared with other Mentha species.
Thymus species are wild species mostly found in the arid lands of Portugal. Possible antimicrobial properties of Thymus essential oils have been investigated. The chemical composition of the essential oils and the antimicrobial activity of Thymus mastichina (L) L. subsp. mastichina, T. camphoratus and T. lotocephalus from different regions of Portugal were analysed.
Hydrodistillation was used to isolate the essential oils and the chemical analyses were performed by gas chromatography (GC) and GC coupled to mass spectrometry. The antimicrobial activity was tested by the disc agar diffusion technique against Candida albicans, Escherichia coli, Listeria monocytogenes, Proteus mirabilis, Salmonella spp. and Staphylococcus aureus. Pure linalool, 1,8-cineole and a mixture (1 : 1) of these compounds were included. Linalool, 1,8-cineole or linalool/1,8-cineole and linalool/1,8-cineole/linalyl acetate were the major components of the essential oils, depending on the species or sampling place. The essential oils isolated from the Thymus species studied demonstrated antimicrobial activity but the micro-organisms tested had significantly different sensitivities.
The antimicrobial activity of essential oils may be related to more than one component.
Portuguese endemic species of Thymus can be used for essential oil production for food spoilage control, cosmetics and pharmaceutical use. Further studies will be required to elucidate the cell targets of the essential oil components.
Microbial transformations of cyclic hydrocarbons have received much attention during the past three decades. Interest in the degradation of environmental pollutants as well as in applications of microorganisms in the catalysis of chemical reactions has stimulated research in this area. The metabolic pathways of various aromatics, cycloalkanes, and terpenes in different microorganisms have been elucidated, and the genetics of several of these routes have been clarified. The toxicity of these compounds to microorganisms is very important in the microbial degradation of hydrocarbons, but not many researchers have studied the mechanism of this toxic action. In this review, we present general ideas derived from the various reports mentioning toxic effects. Most importantly, lipophilic hydrocarbons accumulate in the membrane lipid bilayer, affecting the structural and functional properties of these membranes. As a result of accumulated hydrocarbon molecules, the membrane loses its integrity, and an increase in permeability to protons and ions has been observed in several instances. Consequently, dissipation of the proton motive force and impairment of intracellular pH homeostasis occur. In addition to the effects of lipophilic compounds on the lipid part of the membrane, proteins embedded in the membrane are affected. The effects on the membrane-embedded proteins probably result to a large extent from changes in the lipid environment; however, direct effects of lipophilic compounds on membrane proteins have also been observed. Finally, the effectiveness of changes in membrane lipid composition, modification of outer membrane lipopolysaccharide, altered cell wall constituents, and active excretion systems in reducing the membrane concentrations of lipophilic compounds is discussed. Also, the adaptations (e.g., increase in lipid ordering, change in lipid/protein ratio) that compensate for the changes in membrane structure are treated.
The minimum inhibitory concentrations (MIC) of 60 terpenoids against Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus and Candida albicans have been determined. Hierarchical cluster analysis was used to group the compounds into five groups according to their activity patterns against the four microorganisms. K-Means cluster analysis was then used to confirm these groupings and to show the differences in the activity patterns of the groups. Ten molecular properties of the terpenoids, either calculated via molecular modelling or determined by direct measurement, were then used as variables in a forward stepwise discriminant analysis to identify which variables discriminated between groups. Low water solubility of Group IV compounds, mainly hydrocarbons and acetates, was found to be associated with their relative inactivity. The remaining groups, all containing oxygenated terpenoids, showed characteristic but distinct activity patterns towards the four test organisms. Hydrogen bonding parameters were found to be associated with antimicrobial activity in all cases. Activity against Gram-negative E. coli and P. aeruginosa was associated with a combination of a hydrogen bonding and size parameters. This was not found to be the case for the Gram-positive S. aureus or the yeast C. albicans. Copyright © 1999 John Wiley & Sons, Ltd.
The chemical composition of essential oil obtained by hydrodistillation from the dried fruits of Chaenomeles speciosa was analyzed by GC–MS. Forty compounds, constituting about 85.13% of the total oil, were identified. The main constituents were β-caryophyllene (12.52%), α-terpineol (5.41%), terpinen-4-ol (4.56%) and 1,8-cineole (4.31%). The antimicrobial activity of the oil was evaluated against 10 microorganisms using disc diffusion and broth microdilution methods. The essential oil was found to show a broad spectrum of antimicrobial activity against all the tested bacterial strains. The essential oil had more sensitivity to gram-positive than gram-negative bacteria.
The chemical composition of 40 samples of essential oil of Calamintha nepeta, growing wild in Corsica, was examined. After a preliminary study on a single plant, which allowed definition of the full blossom as the stable period for harvesting, the existence of three chemotypes was demonstrated. Half of the samples were characterized by a menthone/pulegone chemotype, 13 samples present pulegone as the major component associated with menthone, while piperitone and piperitenone oxides were the main components of the last 11 samples. Copyright © 2000 John Wiley & Sons, Ltd.
In this study the antimicrobial activities of five volatiles, which represent main compounds of several essential oils, were tested. Terpineol, (R)-(–)-linalool, carvacrol, (S)-(–)-perillaldehyde and 1,8-cineole were evaluated for their influence on airborne microbes when vaporized with a room diffuser. In the present investigation terpineol and (S)-(–)-perillaldehyde showed the highest antimicrobial activities. The average reduction of the germ count was 59.4% and 42.3%, respectively, after 5 h of spreading in a testing room. Carvacrol (average germ reduction 37.5%) and (R)-(–)-linalool (29.7%) showed lower results. For 1,8-cineole only, no unambiguous antimicrobial effect was detectable. It has to be considered that the amounts of vapour spread during 5 h of testing time were different, depending on the volatility of the scent used. Nevertheless, four of the investigated volatiles showed satisfying antimicrobial action against airborne microbes. Copyright © 2008 John Wiley & Sons, Ltd.
High-performance liquid chromatography with diode array detection (HPLC––DAD) is used to characterize mixtures from chlorophyll a degradation experiments. Overlapping chromatographic peaks are resolved by means of the heuristic evolving latent projections (HELP) method. The HELP method is a self-modelling curve resolution method. No assumptions are made about spectral and/or chromatographic peak shape. In the first step the method establishes the real noise level in the data by use of the so-called zero-component regions. This information is used to reveal selective chromatographic information and the number of chemical species at every retention time in unresolved chromatographic peaks. Utilising the selective chromatographic regions in combination with the zero-concentration windows, unique resolution into concentration profiles and spectra of the pure chemical species is accomplished. HPLC–DAD data from six chlorophyll a degradation experiments were analysed. Consistent results were obtained even with very similar spectra for six or seven overlapping chemical components.
Carvacrol, a natural antimicrobial compound present in the essential oil fraction of oregano and thyme, is bactericidal towards Bacillus cereus. A decrease of the sensitivity of B. cereus towards carvacrol was observed after growth in the presence of non-lethal carvacrol concentrations. A decrease of the melting temperature (Tm) of membranes from 20.5 C to 12.6 C was the immediate effect of the addition of carvacrol. Cells adapted to 0.4 mM carvacrol showed a lower membrane fluidity than non-adapted cells. Adaptation of 0.4 mM carvacrol increased the Tm from 20.5 C to 28.3 C. The addition of carvacrol to cell suspensions of adapted B. cereus cells decreased Tm again to 19.5 C, approximately the same value as for the non-adapted cells in the absence of carvacrol. During adaptation, changes in the fatty acid composition were observed. The relative amount of iso-C13:0, C14:0 and iso-C15:0 increased and cis-C16:1 and C18:0 decreased. The head-group composition also changed, two additional phospholipids were formed and one phospholipid was lacking in the adapted cells. It could be concluded that B. cereus adapts to carvacrol when present at non-lethal concentrations in the growth medium by lowering its membrane fluidity by changing the fatty acid and head-group composition.
The minimum inhibitory concentrations (MIC) of 60 terpenoids against Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus and Candida albicans have been determined. Hierarchical cluster analysis was used to group the compounds into five groups according to their activity patterns against the four micro-organisms. K-Means cluster analysis was then used to confirm these groupings and to show the differences in the activity patterns of the groups. Ten molecular properties of the terpenoids, either calculated via molecular modelling or determined by direct measurement, were then used as variables in a forward stepwise discriminant analysis to identify which variables discriminated between groups. Low water solubility of Group IV compounds, mainly hydrocarbons and acetates, was found to be associated with their relative inactivity. The remaining groups, all containing oxygenated terpenoids, showed characteristic but distinct activity patterns towards the four test organisms. Hydrogen bonding parameters were found to be associated with antimicrobial activity in all cases. Activity against Gram-negative E. coli and P. aeruginosa was associated with a combination of a hydrogen bonding and size parameters. This was not found to be the case for the Gram-positive S. aureus or the yeast C. albicans.
Aerial parts of wild Calamintha nepeta (L.) Savi subsp. nepeta growing spontaneously on the Mediterranean coast (Sardinia Island, Italy) and on the Atlantic coast (Portugal) were used as a matrix for the supercritical extraction of volatile oil with CO(2). The collected extracts were analysed by GC-FID and GC-MS methods and their compositions were compared with that of the essential oil isolated by hydrodistillation, but the differences were not relevant. A strong chemical variability was observed in the essential oils depending on the origin of the samples. The results showed the presence of two chemotypes of C. nepeta. In all Italian samples, pulegone, piperitenone oxide and piperitenone were the main components (64.4-39.9%; 2.5-19.1%; 6.4-7.7%); conversely, the oil extracted from Portuguese C. nepeta is predominantly composed of isomenthone (35.8-51.3%), 1,8-cineole (21.1-21.4%) and trans-isopulegone (7.8-6.0%). The minimal inhibitory concentration (MIC) and the minimal lethal concentration (MLC) were used to evaluate the antifungal activity of the oils against Candida albicans, Candida tropicalis, Candida krusei, Candida guillermondii, Candida parapsilosis, Cryptococcus neoformans, Trichophyton rubrum, Trichophyton mentagrophytes, Microsporum canis, Microsporum gypseum, Epidermophyton floccosum, Aspergillus niger, Aspergillus fumigatus and Aspergillus flavus. The Italian oil, rich in pulegone, exhibited significant antifungal activity against Aspergillus and dermatophyte strains, with MIC values of 0.32-1.25 µL mL(-1).
Microbial transformations of cyclic hydrocarbons have received much attention during the past three decades. Interest in the degradation of environmental pollutants as well as in applications of microorganisms in the catalysis of chemical reactions has stimulated research in this area. The metabolic pathways of various aromatics, cycloalkanes, and terpenes in different microorganisms have been elucidated, and the genetics of several of these routes have been clarified. The toxicity of these compounds to microorganisms is very important in the microbial degradation of hydrocarbons, but not many researchers have studied the mechanism of this toxic action. In this review, we present general ideas derived from the various reports mentioning toxic effects. Most importantly, lipophilic hydrocarbons accumulate in the membrane lipid bilayer, affecting the structural and functional properties of these membranes. As a result of accumulated hydrocarbon molecules, the membrane loses its integrity, and an increase in permeability to protons and ions has been observed in several instances. Consequently, dissipation of the proton motive force and impairment of intracellular pH homeostasis occur. In addition to the effects of lipophilic compounds on the lipid part of the membrane, proteins embedded in the membrane are affected. The effects on the membrane-embedded proteins probably result to a large extent from changes in the lipid environment; however, direct effects of lipophilic compounds on membrane proteins have also been observed. Finally, the effectiveness of changes in membrane lipid composition, modification of outer membrane lipopolysaccharide, altered cell wall constituents, and active excretion systems in reducing the membrane concentrations of lipophilic compounds is discussed. Also, the adaptations (e.g., increase in lipid ordering, change in lipid/protein ratio) that compensate for the changes in membrane structure are treated.
Many cyclic hydrocarbons, e.g. aromatics, cycloalkanes, and terpenes, are toxic to microorganisms. The primary site of the toxic action is probably the cytoplasmic membrane, but the mechanism of the toxicity is still poorly understood. The effects of cyclic hydrocarbons were studied in liposomes prepared from Escherichia coli phospholipids. The membrane-buffer partition coefficients of the cyclic hydrocarbons revealed that these lipophilic compounds preferentially reside in the membrane. The partition coefficients closely correlated with the partition coefficients of these compounds in a standard octanol-water system. The accumulation of hydrocarbon molecules resulted in swelling of the membrane bilayer, as assessed by the release of fluorescence self-quenching of fluorescent fatty acid and phospholipid analogs. Parallel to the expansion of the membrane, an increase in membrane fluidity was observed. These effects on the integrity of the membrane caused an increased passive flux of protons and carboxyfluorescein. In cytochrome c oxidase containing proteoliposomes, both components of the proton motive force, the pH gradient and the electrical potential, were dissipated with increasing concentrations of cyclic hydrocarbons. The dissipating effect was primarily the result of an increased permeability of the membrane for protons (ions). At higher concentrations, cytochrome c oxidase was also inactivated. The effective concentrations of the different cyclic hydrocarbons correlated with their partition coefficients between the membrane and aqueous phase. The impairment of microbial activity by the cyclic hydrocarbons most likely results from hydrophobic interaction with the membrane, which affects the functioning of the membrane and membrane-embedded proteins.
Essential oils from Satureja montana L., Rosmarinus officinalis L., Thymus vulgaris L., and Calamintha nepeta (L.) Savi, were chemically analysed and their antimicrobial and fungicide activities evaluated on the basis of their minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). All four oils have a biotoxic effect, the most active being those from Calamintha and Thymus.
Antiseptics and disinfectants are extensively used in hospitals and other health care settings for a variety of topical and hard-surface applications. A wide variety of active chemical agents (biocides) are found in these products, many of which have been used for hundreds of years, including alcohols, phenols, iodine, and chlorine. Most of these active agents demonstrate broad-spectrum antimicrobial activity; however, little is known about the mode of action of these agents in comparison to antibiotics. This review considers what is known about the mode of action and spectrum of activity of antiseptics and disinfectants. The widespread use of these products has prompted some speculation on the development of microbial resistance, in particular whether antibiotic resistance is induced by antiseptics or disinfectants. Known mechanisms of microbial resistance (both intrinsic and acquired) to biocides are reviewed, with emphasis on the clinical implications of these reports.
Carvacrol, a naturally occurring compound mainly present in the essential oil fraction of oregano and thyme, was studied for its effect on bioenergetic parameters of vegetative cells of the food-borne pathogen Bacillus cereus. Incubation for 30 min in the presence of 1 to 3 mM carvacrol reduced the viable cell numbers exponentially. Carvacrol (2 mM) significantly depleted the intracellular ATP pool to values close to 0 within 7 min. No proportional increase of the extracellular ATP pool was observed. Depletion of the internal ATP pool was associated with a change of the membrane potential (Deltapsi). At concentrations of 0.01 mM carvacrol and above, a significant reduction of Deltapsi was observed, leading to full dissipation of Deltapsi at concentrations of 0.15 mM and higher. Finally, an increase of the permeability of the cytoplasmic membrane for protons and potassium ions was observed (at 0.25 and 1 mM carvacrol, respectively). From this study, it could be concluded that carvacrol interacts with the membranes of B. cereus by changing its permeability for cations like H(+) and K(+). The dissipation of ion gradients leads to impairment of essential processes in the cell and finally to cell death.
Antibiotics are used as chemotherapeutic drugs, and biocides are used as antiseptics, disinfectants, and preservatives. Several factors affect biocidal activity, notably concentration, period of contact, pH, temperature, the presence of interfering material, and the types, numbers, location, and condition of microorganisms. Bacterial cells as part of natural or artificial (laboratory) biofilm communities are much less susceptible than planktonic cells to antibiotics and biocides. Assessment of biocidal activity by bactericidal testing is more relevant than by determination of minimum inhibitory concentrations. Biocides and antibiotics may show some similarities in their mechanisms of action and common mechanisms of bacterial insusceptibility may apply, but there are also major differences. In the laboratory, bacteria can become less susceptible to some biocides. Decreased resistance may be stable or unstable and may be accompanied by a low-level increase in antibiotic resistance. Laboratory studies are useful for examining stress responses and basic mechanisms of action and of bacterial insusceptibility to antibacterial agents. Translation of such findings to the clinical and environmental situations to provide evidence of a possible relation between biocide use and clinical antibiotic resistance is difficult and should be viewed with caution.