Chemical Composition and Anti-inflammatory Activity of Algerian Thymus vulgaris Essential Oil.

This work aims to elucidate the chemical composition of two essential oil (EO) samples obtained from the leaves of Thymus vulgaris L. (Lamiaceae) collected in two regions of Northwestern Algeria (Tlemcen and Mostaganem) and to assess their in vivo acute toxicity and anti-inflammatory activity. Sixty-six compounds could be identified by means of simultaneous GC-FID and GC-MS, accounting for 99.3% of total thyme oil of Mostaganem (EO.TM) and 99.0% of Tlemcen (EO.TT). In both samples, thymol was the major component, amounting to 59.5% (EO.TM) and 67.3% (EO.TT) of the total oil. EO.TT proved to be acutely toxic to mice at a dose of 4500 mg/kg p.o., whereas EO.TM did not show signs of acute toxicity, even at the highest dose tested (5000 mg/kg p.o.). Both EO samples were proven to possess anti-inflammatory activities, significantly reducing carrageenan-induced paw edema in mice (after 6 hours at a dose -of 400 mg/kg p.o) at 58.4% for EO.TT and 50.4% for EO.TM, respectively. In conclusion, it could be demonstrated that EOs of T. vulgaris exhibit a considerable in vivo anti-inflammatory activity at non-toxic doses.

Essential Oils, Part VI: Sandalwood Oil, Ylang-Ylang Oil, and Jasmine Absolute.

In this article, some aspects of sandalwood oil, ylang-ylang oil, and jasmine absolute are discussed including their botanical origin, uses of the plants and the oils and absolute, chemical composition, contact allergy to and allergic contact dermatitis from these essential oils and absolute, and their causative allergenic ingredients.

Essential Oils, Part V: Peppermint Oil, Lavender Oil, and Lemongrass Oil.

Some aspects of peppermint oil, lavender oil, and lemongrass oil are discussed including their botanical origin, uses of the plants and the oils, chemical composition, contact allergy to and allergic contact dermatitis from these essential oils, and causative allergenic ingredients.

Antimicrobial Activity and Chemical Analysis of the Essential Oil of Algerian Juniperus phoenicea.

The essential oils of Juniperus phoenicea L. from Algeria were obtained by hydrodistillation and analyzed by GC-FID and GC-MS. Concerning their chemical composition, 74, 61 and 72 volatile compounds were identified from fresh leaves, dried leaves and berries, representing 88.8%, 91.3% and 94.7% of the total composition, respectively. The main monoterpene in the oils of fresh leaves, dried leaves and berries was a-pinene (29.6% / 55.9% / 56.6%), accompanied by lesser amounts of the sesquiterpenes ß-caryophyllene (2.6% / 1.6% /1.2%) and germacrene D (2.01% / 1.7% / 1.5%), respectively. Antibacterial activity of J. phoenicea essential oils was tested against one Gram-negative and four Gram-positive bacterial strains and the yeast Candida albicans, responsible for nosocomial infections. As references, 14 antibiotics and 5 antifungal agents were evaluated. The berry essential oil was ineffective against all but two of the strains tested, whereas the essential oil of dried leaves significantly inhibited all strains but Pseudomonas aeruginosa, which turned out to be the most resistant strain overall. However, Escherichia coli was the most susceptible to the essential oils tested. The essential oil of dry leaves was highly active against Candida albicans, outclassing even the standard antifungal substances. These promising results could substantiate the use of essential oils in the treatment of hospital-acquired infections.

Essential Oils, Part IV: Contact Allergy.

Nearly 80 essential oils (including 2 jasmine absolutes) have caused contact allergy. Fifty-five of these have been tested in consecutive patients suspected of contact dermatitis, and nine (laurel, turpentine, orange, tea tree, citronella, ylang-ylang, sandalwood, clove, and costus root) showed greater than 2% positive patch test reactions. Relevance data are generally missing or inadequate. Most reactions are caused by application of pure oils or high-concentration products. The clinical picture depends on the responsible product. Occupational contact dermatitis may occur in professionals performing massages. The (possible) allergens in essential oils are discussed. Several test allergens are available, but patients should preferably be tested with their own products. Co-reactivity with other essential oils and the fragrance mix is frequent, which may partly be explained by common ingredients. Patch test concentrations for essential oils are suggested.

Tea tree oil: contact allergy and chemical composition.

In this article, contact allergy to, and the chemical composition of, tea tree oil (TTO) are reviewed. This essential oil is a popular remedy for many skin diseases, and may be used as neat oil or be present in cosmetics, topical pharmaceuticals and household products. Of all essential oils, TTO has caused most (published) allergic reactions since the first cases were reported in 1991. In routine testing, prevalences of positive patch test reactions have ranged from 0.1% to 3.5%. Nearly 100 allergic patients have been described in case reports and case series. The major constituents of commercial TTO are terpinen-4-ol, γ-terpinene, 1,8-cineole, α-terpinene, α-terpineol, p-cymene, and α-pinene. Fresh TTO is a weak to moderate sensitizer, but oxidation increases its allergenic potency. The major sensitizers appear to be ascaridole, terpinolene, α-terpinene, 1,2,4-trihydroxymenthane, α-phellandrene, and limonene. The clinical picture of allergic contact dermatitis caused by TTO depends on the products used. Most reactions are caused by the application of pure oil; cosmetics are the culprits in a minority of cases. Patch testing may be performed with 5% oxidized TTO. Co-reactivity to turpentine oil is frequent, and there is an overrepresentation of reactions to fragrance mix I, Myroxylon pereirae, colophonium, and other essential oils.

Part II: General Aspects.

In this second article on contact allergy to and chemical composition of essential oils, some general aspects of essential oils are kprovided, including what they are, their applications, their mode of production, factors influencing their chemical composition, analysis of essential oil, and quality aspects.

Analysis and Olfactory Description of Four Essential Oils from Vietnam.

The present study evaluates the chemical composition and olfactory description of the essential oils of Asarum glabrum Merr., Calocedrs macrolepis Kurz, Cunninghamia lanceolata (Lamb.) Hook. and Glyptostrobus pensilis (Stainton ex D.Don) K. Koch. The essential oils were obtained by hydrodistillation in a Clevenger-type apparatus and analyzed by GC-FID and GC-MS. Concerning their chemical composition, 66, 42, 57 and 21 volatile compounds were identified from dried leaves in the case of Asarum glabrum Merr. and wood for the other three, representing 98.7%, 67.2%,,92.0% and 87.5 % of the total composition, respectively. The main compounds of Asarum glabrum oil were safrole (38.1%), apiole (10.8%) and myristicin (8.0%); of Calocedrus macrolepis verbenone (9.3%), piperitone (8.6 %), a-terpineol (6.0%) and (Z)-p-terpineol (5.3%); of Cunninghamia lanceolata oil cedrol (26.3%), a-terpineol (24.1%) and camphor (7.0%); and of Glyptostrobus pensilis oil dihydro-eudesmol isomer (assumed) (18.3%), cedrol (16.4%), occidentalol (13.2%) and elemol (9.0%).

Fatty Acid Methyl Ester Composition of Some Turkish Apiaceae Seed Oils: New Sources for Petroselinic Acid.

The seed oils of twenty-six species of Apiaceae belonging to the genera Bunium, Cnidium, Ferula, Ferulago, Heracleum, Hippomarathrum, Malabaila, Myrrhoides, Olymposciadium, Pimpinella, Prangos, Szovitsia, Trigonasciadium, Trinia and Zosima, collected in Turkey, were investigated for their oil content, and amount of petroselinic acid (PA), as well as for the composition of their fatty acid methyl esters (FAMEs) by GC-MS. Seed oil content ranged from 7.1% in Szovitsia callicarpa to 29.3% in Ferda haussknechtii. The results showed that the seed oils of the studied species contained high amounts of PA (1.2-72.2%), followed by significant amounts of linoleic (LA, 13.8-50.8%) and oleic (OA, 4.2-61.6%) acids. PA was found in all the analyzed species, except for Olymposciadium caespitosum, which belongs to a monotypic endemic genus of the family. According to data from our study, PA was found to be predominantly in the seed oils of Hippomarathrum cristatum (72.2%), Trinia glauca (64.9%) and Bunium microcarpum (59.7%) and, therefore these species might be considered as new sources of PA, and represent a potential oleochemical raw material. This is the first extensive study of the composition ofTurkish Apiaceae species. The high amounts of PA may also have chemotaxonomic significance.

Chemical Composition of Vietnamese Essential Oils of Cinnamomum rigidifolium, Dasymaschalon longiusculum, Fissistigma maclurei and Goniothalamus albiflorus.

Cinnamomum rigidifolium, Dasymaschalon longiusculum, Fissistigma maclurei and Goniothalamus albiflorus were collected from different landscapes in Vietnam and hydro distilled to produce essential oils with yields from 0.15 - 0.35%. The oils were analyzed by GC-MS-FID and rechecked by measurements on two different instrumentation configurations. The main components of the studied essential oils were for Cinnamomum rigidifolium linalool (19.4%), α-pinene (13.8%), verbenone (9.9%) and cis-verbenol (8.9%), total identified 90.5%; for Dasymaschalon longiusculum spathulenol (21.4%), caryophyllene oxide (17.6%), a-pinene (5.5%) and ß-pinene (5.2%), total identified 70.1%; for Fissistigma maclurei spathulenol (17.8%), guaia-6,10(14)-diene-40-ol (10.3%), (E)-ß-caryophyllene (7.3%) and caryophyllene oxide (7.0%), total identified 75.3% and for Goniothalamus albiflorus 1,8-cineole (13.2%), α-pinene (10.6%), ledol (7.5%) and caryophyllene oxide (7.3%), total identified 78.0%.

Chemical Composition, Antioxidant, Antimicrobial and Insecticidal Activities of Essential Oil from a Moroccan Endemic Plant: Bubonium imbricatum.

The chemical composition, antioxidant, antimicrobial and insecticidal properties of essential oil obtained by hydro-distillation from Bubonium imbricatum Cav. have been investigated. The essential oil of aerial parts was analyzed by GC-FID and GC-MS. A total of 63 compounds were identified representing more than 82% of the oil. The major components were cis-chrysanthenyl acetate (31.2%) and thymol isobutyrate (3.4%). The antioxidant activity was evaluated by the DPPH and reducing power test. The data showed moderate activity compared with the reference compounds. Our results showed strong activity of the investigated oil against all tested microorganisms. The highest antibacterial activity was observed against Bacillus subtilis (inhibition zone= 18 ± 0.21, MIC= 0.18 mg/mL). In general, Gram-positive bacteria were more susceptible than Gram-negative ones. Candida parapsilosis was the most sensitive among the Candida strains tested. LD50 and LD90 values were 33.1 and 53.1 ppm against 1-d-old larvae of Aedes aegypti L.

Chemical Composition and Biological Activity of Essential Oils from Wild Growing Aromatic Plant Species of Skimmia laureola and Juniperus macropoda from Western Himalaya.

The Himalayan region is very rich in a great variety of medicinal plants. In this investigation the essential oils of two selected species are described for their antimicrobial and larvicidal as well as biting deterrent activities. Additionally, the odors are characterized. Analyzed by simultaneous GC-MS and GC-FID, the essential oils' chemical compositions are given. The main components of Skimmia laureola oil were linalool and linalyl acetate whereas sabinene was found as the main compound for Juniperus macropoda essential oil. Antibacterial testing by agar dilution assay revealed highest activity of S. laureola oil against all tested bacteria, followed by J. macropoda oil. Antifungal activity was evaluated against the strawberry anthracnose causing plant pathogens Colletotrichum acutatum, C. fragariae and C. gloeosporioides. Juniperus macropoda essential oil indicated higher antifungal activity against all three pathogens than S. laureola oil. Both essential oils showed biting deterrent activity above solvent control but low larvicidal activity.

Composition and Comprehensive Antioxidant Activity of Ginger (Zingiber officinale) Essential Oil from Ecuador.

In the present study, the chemical composition and antioxidant potential of an essential oil of ginger rhizomes from Ecuador was elucidated. The analysis of the essential oil by GC/FID/MS resulted in identification of 71 compounds, of which the main are citral (geranial 10.5% and neral 9.1%), α-zingiberene (17.4%), camphene (7.8%), α-farnesene (6.8%) and ß-sesquiphellandrene (6.7%). The in vitro antioxidant activity of the essential oil expressed by IC50 in descending order is: hydroxyl radical (OH*) scavenging (0.0065 µg/mL) > chelating capacity (0.822 µg/mL) > 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid radical cation (ABTS*+) scavenging (3.94 µg/mL) > xanthine oxidase inhibition (138.0 µg/mL) > oxygen radical (O2*) scavenging (404.0 µg/mL) > 2,2- diphenyl-1-picrylhydrazyl radical (DPPH*) scavenging (675 µg/mL). Lipid peroxidation inhibition of the essential oil was less efficient than butylhydroxytoluol (BHT) in both stages, i.e. hydroperoxide and malondialdehyde formation. In vivo studies in Saccharomyces cerevisiae demonstrated a significant dose-dependent increase in antioxidant marker enzymes, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), blocking the oxidation processes in yeast cells. Moreover, ginger essential oil in concentrations of 1.6 mg/mL increases the viability of cells to oxidative stress induced by H2O2.

Chemical composition and biological activity of essential oils of Dracocephalum heterophyllum and Hyssopus officinalis from Western Himalaya.

The essential oils of two representatives of the Lamiaceae, Dracocephalum heterophyllum Benth. and Hyssopus officinalis L., are described for their antifungal, antibacterial, larvicidal and inect biting deterrent activities. Additionally, the chemical compositions of the essential oils, analyzed by simultaneous GC-MS and GC-FID, and odor descriptions are given. The main components of H. officinalis oil were pinocarvone, cis-pinocamphone, and ß-pinene. Citronellol was found as the main compound of D. heterophyllum essential oil. Antibacterial testing by agar dilution assay revealed greater activity of D. heterophyllum against Staphylococcus aureus compared with H. officinalis. D. heterophyllum essential oil also showed promising antifungal activity against Colletotrichum species and was more toxic to Aedes aegypti larvae in a larvicial bioassay. Both essential oils showed high activity in the biting deterrent bioassay.

Cytotoxic active constituents of essential oils of Curcuma longa and Curcuma zanthorrhiza.

The polar and apolar fractions of Curcuma longa and C. zanthorriza enriched by ar-turmerone, ar-curcumene and xanthorrizol were screened for cytotoxic activity against the HeLa cell line. Actinomycin D and curcumin were used as reference samples, both known for their cytotoxic properties. Amongst all fractions tested, the xanthorrizol fraction (CC50: 26.1 ± 1.9 µM) showed the strongest cytotoxic properties similar to those of curcumin (CC50: 8.1 ± 1.7 µM). Further studies also revealed that the cytotoxic effects of the extracts and pure compounds are caused by apoptosis induction identified by the cleaved form of PARP protein.

Antimicrobial activity of nerolidol and its derivatives against airborne microbes and further biological activities.

Nerolidol and its derivatives, namely cis-nerolidol, O-methyl-nerolidol, O-ethyl-nerolidol, (-)-α-bisabolol, trans,trans-farnesol and its main natural source cabreuva essential oil, were tested for their antimicrobial activity against airborne microbes and antifungal properties against plant pathogens. Among the tested compounds, α-bisabolol was the most effective antimicrobial agent and trans,trans-farnesol showed the best antifungal activity.

Chemical composition and antifungal activity of Aaronsohnia pubescens essential oil from Algeria.

In the present study, the chemical composition of the essential oil obtained from the aerial parts of Aaronsohnia pubescens (Desf.) K.Bremer & Humphries (Asteraceae), a chamomile-like medicinal plant, was studied. Using both GC-MS and GC-FID methods, 58 volatile compounds could be identified representing 96.6% of the total essential oil composition. The main compounds in the essential oil were monoterpene hydrocarbons such as (Z)-ß-ocimene (53.8%), myrcene (15.2%) and α-pinene (7.7%). Moreover, the essential oil of A. pubescens was tested for its antifungal activity against seven strains of phytopathogenic fungi , i.e. Aspergillus niger, A. flavus, Penicillium purpurogenum, P. jensenii, P. expansum, and Fusarium oxysporum f.sp. albedinis, using the disc diffusion method. With the exception of P. jensenii, A. pubescens essential oil demonstrated a considerable antifungal activity against all tested strains. The present results confirm the traditional use of A. pubescens as a food preservative.

Chemical composition and biological effects of Artemisia maritima and Artemisia nilagirica essential oils from wild plants of western Himalaya.

Artemisia species possess pharmacological properties that are used for medical purposes worldwide. In this paper, the essential oils from the aerial parts of Artemisia nilagirica and Artemisia maritima from the western Indian Himalaya region are described. The main compounds analyzed by simultaneous GC/MS and GC/FID were camphor and 1,8-cineole from A. maritima, and camphor and artemisia ketone from A. nilagirica. Additionally, the oils were evaluated for their antibacterial, antifungal, mosquito biting deterrent, and larvicidal activities. A. nilagirica essential oil demonstrated nonselective antifungal activity against plant pathogens Colletotrichum acutatum, Colletotrichum fragariae, and Colletotrichum gloeosporioides, whereas A. maritima did not show antifungal activity. Both Artemisia spp. exhibited considerable mosquito biting deterrence, whereas only A. nilagirica showed larvicidal activity against Aedes aegypti. Antibacterial effects assessed by an agar dilution assay demonstrated greater activity of A. maritima essential oil against Staphylococcus aureus and Pseudomonas aeruginosa compared to A. nilagirica.

Chemical composition, olfactory analysis and antibacterial activity of Thymus vulgaris chemotypes geraniol, 4-thujanol/terpinen-4-ol, thymol and linalool cultivated in southern France.

The essential oils of four chemotypes of Thymus vulgaris L. (Lamiaceae) were analyzed for their composition and antibacterial activity to assess their different properties. GC-MS and GC-FID analyses revealed that the essentials oils can be classified into the chemotypes thymol (41.0% thymol), geraniol (26.4% geraniol), linalool (72.5% linalool) and 4-thujanol/terpinen-4-ol (42.2% cis- and 7.3% trans-sabinene hydrate, 6.5 % terpinen-4-ol). The olfactory examination confirmed the explicit differences between these chemotypes. Furthermore, antibacterial activity was investigated against several strains of two Gram-positive (Brochothrix thermosphacta and Staphylococcus aureus) and four Gram-negative food-borne bacteria (Escherichia coli, Salmonella abony, Pseudomonas aeruginosa and P. fragi). All essential oil samples were demonstrated to be highly effective against Gram-positive strains, whereas the impact on Gram-negative microorganisms was significantly smaller, but still considerable. The results obtained indicate that, despite their different properties, the essential oils of selected T. vulgaris chemotypes are potent antimicrobials to be employed as useful additives in food products as well as for therapeutic applications.