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1.  Effect of Various Essential Oils Isolated from Douglas Fir Needles upon Sheep and Deer Rumen Microbial Activity 
Applied Microbiology  1967;15(4):777-784.
The effects of essential oils isolated from Douglas fir needles on sheep and deer rumen microbial activity were tested by use of an anaerobic manometric technique. Rumen microorganisms were obtained from a sheep which had been fed mainly on alfalfa hay and dried range grass. One deer used in this study had access to Douglas fir trees the year around, whereas the other deer had no access to Douglas fir. All of the monoterpene hydrocarbons isolated from Douglas fir needles—α-pinene, β-pinene, limonene, myrcene, camphene, Δ3-carene, and terpinolene—promoted only slightly or had no effect on deer rumen microbial activity, whereas all of them promoted activity in sheep rumen microbes, except Δ3-carene and terpinolene, which inhibited activity. Of the oxygenated monoterpenes, all monoterpene alcohols—α-terpineol, terpinen-4-ol, linalool, citronellol, and fenchyl alcohol—strongly inhibited the rumen microbial activity of both sheep and deer. Monoterpene esters (bornyl acetate) produced mild inhibition for both sheep and deer microbes, and citronellyl acetate inhibited rumen microbial activity in sheep, whereas it promoted activity in both deer. Monoterpene aldehyde (citronellal) inhibited the activity of rumen microbes from both sheep and deer having no access to Douglas fir from the Hopland Field Station, whereas they produced no effect upon the deer having access to Douglas fir from the Masonite forest. Rumen microbial activity for sheep and deer was promoted slightly with aliphatic ester (ethyl-n-caproate). There was a marked difference between sheep and deer rumen microbes as affected by addition of the various essential oils. The monoterpene hydrocarbons promoted activity more on sheep rumen microbes than on deer, and the monoterpene alcohols inhibited sheep rumen microbial activity more than that of deer. Furthermore, the deer rumen microbes from Hopland Field Station were affected more than the deer from Masonite forest.
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PMCID: PMC547062  PMID: 6049303
2.  Antioxidant and Antibacterial Activities of Crude Extracts and Essential Oils of Syzygium cumini Leaves 
PLoS ONE  2013;8(4):e60269.
This research highlights the chemical composition, antioxidant and antibacterial activities of essential oils and various crude extracts (using methanol and methylene chloride) from Syzygium cumini leaves. Essential oils were analyzed by gas chromatography-mass spectrometry (GC-MS).The abundant constituents of the oils were: α-pinene (32.32%), β-pinene (12.44%), trans-caryophyllene (11.19%), 1, 3, 6-octatriene (8.41%), delta-3-carene (5.55%), α-caryophyllene (4.36%), and α-limonene (3.42%).The antioxidant activities of all extracts were examined using two complementary methods, namely diphenylpicrylhydrazyl (DPPH) and ferric reducing power (FRAP). In both methods, the methanol extract exhibited a higher activity than methylene chloride and essential oil extracts. A higher content of both total phenolics and flavonoids were found in the methanolic extract compared with other extracts. Furthermore, the methanol extract had higher antibacterial activity compared to methylene chloride and the essential oil extracts. Due to their antioxidant and antibacterial properties, the leaf extracts from S. cumini may be used as natural preservative ingredients in food and/or pharmaceutical industries.
doi:10.1371/journal.pone.0060269
PMCID: PMC3625181  PMID: 23593183
3.  Chemical composition and antigenotoxic properties of Lippia alba essential oils 
Genetics and Molecular Biology  2011;34(3):479-488.
The present work evaluated the chemical composition and the DNA protective effect of the essential oils (EOs) from Lippia alba against bleomycin-induced genotoxicity. EO constituents were determined by Gas Chromatography/Mass Spectrometric (GC-MS) analysis. The major compounds encountered being citral (33% geranial and 25% neral), geraniol (7%) and trans-β-caryophyllene (7%) for L. alba specimen COL512077, and carvone (38%), limonene (33%) and bicyclosesquiphellandrene (8%) for the other, COL512078. The genotoxicity and antigenotoxicity of EO and the compounds citral, carvone and limonene, were assayed using the SOS Chromotest in Escherichia coli. The EOs were not genotoxic in the SOS chromotest, but one of the major compound (limonene) showed genotoxicity at doses between 97 and 1549 mM. Both EOs protected bacterial cells against bleomycin-induced genotoxicity. Antigenotoxicity in the two L. alba chemotypes was related to the major compounds, citral and carvone, respectively. The results were discussed in relation to the chemopreventive potential of L. alba EOs and its major compounds.
doi:10.1590/S1415-47572011005000030
PMCID: PMC3168191  PMID: 21931523
Lippia alba; essential oil; antigenotoxicity; bleomycin; SOS chromotest
4.  Chemical Composition, Antioxidant, Anti-Inflammatory and Anti-Proliferative Activities of Essential Oils of Plants from Burkina Faso 
PLoS ONE  2014;9(3):e92122.
This research highlights the chemical composition, antioxidant, anti-inflammatory and anti-proliferative activities of essential oils from leaves of Ocimum basilicum, Ocimum americanum, Hyptis spicigera, Lippia multiflora, Ageratum conyzoides, Eucalyptus camaldulensis and Zingiber officinale. Essential oils were analyzed by gas chromatography–mass spectrometry and gas chromatography–flame ionization detector. Major constituents were α-terpineol (59.78%) and β-caryophyllene (10.54%) for Ocimum basilicum; 1, 8-cineol (31.22%), camphor (12.730%), α-pinene (6.87%) and trans α-bergamotene (5.32%) for Ocimum americanum; β-caryophyllene (21%), α-pinene (20.11%), sabinene (10.26%), β-pinene (9.22%) and α-phellandrene (7.03%) for Hyptis spicigera; p-cymene (25.27%), β-caryophyllene (12.70%), thymol (11.88), γ-terpinene (9.17%) and thymyle acetate (7.64%) for Lippia multiflora; precocene (82.10%)for Ageratum conyzoides; eucalyptol (59.55%), α-pinene (9.17%) and limonene (8.76%) for Eucalyptus camaldulensis; arcurcumene (16.67%), camphene (12.70%), zingiberene (8.40%), β-bisabolene (7.83%) and β-sesquiphellandrène (5.34%) for Zingiber officinale. Antioxidant activities were examined using 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) methods. O. basilicum and L. multiflora exhibited the highest antioxidant activity in DPPH and ABTS tests, respectively. Anti-inflammatory properties were evaluated by measuring the inhibition of lipoxygenase activity and essential oil of Z. officinale was the most active. Anti-proliferative effect was assayed by the measurement of MTT on LNCaP and PC-3 prostate cancer cell lines, and SF-763 and SF-767 glioblastoma cell lines. Essential oils from A. conyzoides and L. multiflora were the most active on LNCaP and PC-3 cell lines, respectively. The SF-767 glioblastoma cell line was the most sensitive to O. basilicum and L. multiflora EOs while essential oil of A. conyzoides showed the highest activity on SF-763 cells. Altogether these results justify the use of these plants in traditional medicine in Burkina Faso and open a new field of investigation in the characterization of the molecules involved in anti-proliferative processes.
doi:10.1371/journal.pone.0092122
PMCID: PMC3963878  PMID: 24662935
5.  Some Effects of Douglas Fir Terpenes on Certain Microorganisms 
The Douglas fir terpene α-pinene was shown to inhibit the growth of a variety of bacteria and a yeast. Other terpenes of the Douglas fir, including limonene, camphene, and isobornyl acetate, were also inhibitory to Bacillus thuringiensis. All terpenes were inhibitory at concentrations normally present in the fir needle diet of Douglas fir tussock moth larvae. The presence of such terpenes in the diet of these insects was found to strongly influence the infectivity of B. thuringiensis spores for the Douglas fir tussock moth larvae. The terpene α-pinene destroyed the cellular integrity and modified mitochondrial activity in certain microorganisms.
PMCID: PMC291570  PMID: 16345609
6.  GC-MS analysis of insecticidal essential oil of flowering aerial parts of Saussurea nivea Turcz 
Background
Several species from Saussurea have been used in the traditional medicine, such as S. lappa, S. involucrate, and S. obvallata. There is no report on medicinal use of S. nivea. The aim of this research was to determine chemical composition and insecticidal activity of the essential oil of S. nivea Turcz (Asteraceae) aerial parts against maize weevils (Sitophilus zeamais Motschulsky) for the first time.
Results
Essential oil of S. nivea flowering aerial parts was obtained by hydrodistillation and analyzed by gas chromatography–mass spectrometry (GC-MS). A total of 43 components of the essential oil of S. nivea were identified. The principal compounds in the essential oil were (+)-limonene (15.46%), caryophyllene oxide (7.62%), linalool (7.20%), α-pinene (6.43%), β-pinene (5.66%) and spathulenol (5.02%) followed by β-eudesmoll (4.64%) and eudesma-4,11-dien-2-ol (3.76%). The essential oil of S. nivea exhibited strong contact toxicity against S. zeamais with an LD50 value of 10.56 μg/adult. The essential oil also possessed fumigant toxicity against S. zeamais with an LC50 value of 8.89 mg/L.
Conclusion
The study indicates that the essential oil of S. nivea flowering aerial parts has a potential for development into a natural insecticide/fumigant for control of insects in stored grains.
doi:10.1186/2008-2231-20-14
PMCID: PMC3555723  PMID: 23351592
Saussurea nivea; Sitophilus zeamais; Contact toxicity; Fumigant; Essential oil composition
7.  Changes of Peel Essential Oil Composition of Four Tunisian Citrus during Fruit Maturation 
The Scientific World Journal  2012;2012:528593.
The present work investigates the effect of ripening stage on the chemical composition of essential oil extracted from peel of four citrus: bitter orange (Citrus aurantium), lemon (Citrus limon), orange maltaise (Citrus sinensis), and mandarin (Citrus reticulate) and on their antibacterial activity. Essential oils yields varied during ripening from 0.46 to 2.70%, where mandarin was found to be the richest. Forty volatile compounds were identified. Limonene (67.90–90.95%) and 1,8-cineole (tr-14.72%) were the most represented compounds in bitter orange oil while limonene (37.63–69.71%), β-pinene (0.63–31.49%), γ-terpinene (0.04–9.96%), and p-cymene (0.23–9.84%) were the highest ones in lemon. In the case of mandarin, the predominant compounds were limonene (51.81–69.00%), 1,8-cineole (0.01–26.43%), and γ-terpinene (2.53–14.06%). However, results showed that orange peel oil was dominated mainly by limonene (81.52–86.43%) during ripening. The results showed that ripening stage influenced significantly the antibacterial activity of the oils against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. This knowledge could help establish the optimum harvest date ensuring the maximum essential oil, limonene, as well as antibacterial compounds yields of citrus.
doi:10.1100/2012/528593
PMCID: PMC3353483  PMID: 22645427
8.  Liquid/air partition coefficients of four terpenes. 
The liquid/air partition coefficients of four common terpenes, alpha-pinene, beta-pinene, 3-carene, and limonene, have been determined in vitro using head space technique. The liquids used were water, human blood, and olive oil. alpha-Pinene, beta-pinene, and 3-carene were practically insoluble in water and limonene was slightly soluble; all were readily dissolved in olive oil. The oil/air partition coefficients ranged from 2900 to 5700 in the order alpha-pinene, beta-pinene, 3-carene, and limonene. The blood/air partition coefficients ranged from 15 to 42 in the same order as for oil/air.
PMCID: PMC1035097  PMID: 2310709
9.  Chemical composition, antimicrobial and antibiofilm activity of the essential oil and methanol extract of the Mediterranean cypress (Cupressus sempervirens L.) 
Background
Cupressus sempervirens is a medicinal plant traditional, its dried leaves are used in treatment of stomach pain, diabetes, inflammation, toothache, laryngitis and as contraceptive.
Methods
The present study was conducted to evaluate the in vitro antimicrobial, antibiofilm and determination chemical contents of the essential oil (Eo) and methanol extract from Mediterranean C. sempervirens L. The chemical composition of a hydrodistilled Eo of C. sempervirens was analyzed by a GC and GC/MS system.
Results
A total of 20 constituents representing 98.1% of the oil were identified: α-pinene (48.6%), δ-3-carene (22.1%), limonene (4.6%) and α-terpinolene (4.5%) were the main components comprising 79.8% of the oil. The antimicrobial test results showed that the methanol extract of C. sempervirens strongly inhibited the growth of the test bacteria studied, except for yeast species while the Eo had moderate antibacterial, but no anti-candida activity. Klebsiella pneumoniae was proven to be the most susceptible against methanol extract. The exposure time of Eo and methanol extract for complete inhibition of cell viability of K. pneumoniae was found to be 250 μg at 30 min and 500 μg at 120 min, respectively. The antibiofilm potential of the samples was evaluated using methods of PVC microtiter and eradication on biomaterial. Visual results showed visible biofilm eradication from the surface of intravenous infusion tube at 500 μg of Eo and methanol extract.
Conclusions
The results presented here may suggest that the Eo and extracts of C. sempervirens possess antimicrobial and antibiofilm properties, and therefore, can be used as natural preservative ingredients in food and/or pharmaceuticals.
doi:10.1186/1472-6882-14-179
PMCID: PMC4052795  PMID: 24890383
Mediterranean Cupressus sempervirens L; Methanol extract; Essential oil; GC-MS; Antimicrobial activity; Antibiofilm activity
10.  Significant Mean and Extreme Climate Sensitivity of Norway Spruce and Silver Fir at Mid-Elevation Mesic Sites in the Alps 
PLoS ONE  2012;7(11):e50755.
Climate forcing is the major abiotic driver for forest ecosystem functioning and thus significantly affects the role of forests within the global carbon cycle and related ecosystem services. Annual radial increments of trees are probably the most valuable source of information to link tree growth and climate at long-term time scales, and have been used in a wide variety of investigations worldwide. However, especially in mountainous areas, tree-ring studies have focused on extreme environments where the climate sensitivity is perhaps greatest but are necessarily a biased representation of the forests within a region. We used tree-ring analyses to study two of the most important tree species growing in the Alps: Norway spruce (Picea abies) and silver fir (Abies alba). We developed tree-ring chronologies from 13 mesic mid-elevation sites (203 trees) and then compared them to monthly temperature and precipitation data for the period 1846–1995. Correlation functions, principal component analysis and fuzzy C-means clustering were applied to 1) assess the climate/growth relationships and their stationarity and consistency over time, and 2) extract common modes of variability in the species responses to mean and extreme climate variability. Our results highlight a clear, time-stable, and species-specific response to mean climate conditions. However, during the previous-year's growing season, which shows the strongest correlations, the primary difference between species is in their response to extreme events, not mean conditions. Mesic sites at mid-altitude are commonly underrepresented in tree-ring research; we showed that strong climatic controls of growth may exist even in those areas. Extreme climatic events may play a key role in defining the species-specific responses on climatic sensitivity and, with a global change perspective, specific divergent responses are likely to occur even where current conditions are less limited.
doi:10.1371/journal.pone.0050755
PMCID: PMC3510186  PMID: 23209823
11.  Composition and Antimicrobial Activity of the Essential Oil from Leaves of Curcuma longa L. Kasur Variety 
The essential oil from the leaves of Curcuma longa L. Kasur variety grown in Pakistan was extracted by hydro-distillation. Chemical constituents of the essential oil were identified by gas chromatography/mass spectrometry. The chromatographic analysis of oil showed 25 constituents, out of which nine chemical constituents were identified. The eucalyptol (10.27%) was the major component of the essential oil. α-pinene (1.50%), β-phellandrene (2.49%), β-pinene (3.57%), limonene (2.73%), 1,3,8-p-menthatriene (1.76%), ascaridole epoxide (1.452%), 2-methylisoborneol (2.92%), 5-isopropyl-6-methyl-hepta-3, dien-2-ol (2.07%) were also present in considerable quantity. The antimicrobial properties of leaves of Curcuma longa were tested by disc diffusion method against various human pathogens, including eight fungal and five bacterial strains. Essential oil showed maximum resistance against Fusarium miniformes MAY 3629 followed by Bacillus subtilis ATCC 6633 whereas; it exhibited least resistance against Fusarium oxysporium ATCC 48122. The results of the antimicrobial assay revealed that essential oil showed significant inhibitory activity against the tested organisms.
doi:10.4103/0250-474X.113544
PMCID: PMC3719142  PMID: 23901173
Antimicrobial effects; Curcuma longa L; essential oil; gas chromatography/mass spectrometry; hydro-distillation; leaves
12.  Chemical composition of essential oil of Ferulago macrocarpa (Fenzl) Boiss. fruits 
Water-distilled essential oil of Ferulago macrocarpa (Umbelliferae) fruits was analyzed using GC-MS for the first time. Forty-two components comprising 99.5% of the total oil were identified, of which bornyl acetate (40.8%), 2,3,6-trimethyl benzaldehyde (7.2%), δ-selinene (5.5%), 1,10-di-epi-cubenol (5.1%), germacrene D (3.5%), β-phellandrene (3.5%) and α-pinene (3.4%) were found to be the major components. The oil of F. macrocarpa fruits consisted of 15 monoterpene hydrocarbons (21.4%), 6 oxygenated monoterpenes (42.2%), 17 sesquiterpene hydrocarbons (22.4%) and one oxygenated sesquiterpene (5.1%). Three benzenoid derivatives also comprised 8.4% of the oil. Monoterpenes and sesquiterpenes comprised 63.6% and 27.5% of the F. macrocarpa fruits essential oil respectively; however, bornyl acetate (40.8%) was identified as the most abundant component of the oil.
PMCID: PMC3501929  PMID: 23181098
Ferulago macrocarpa; bornyl acetate; 2; essential oil composition; GC/MS; bornyl acetate; 2,3,6-trimethyl benzaldehyde
13.  Antimicrobial Activity and Chemical Composition of Essential Oil From the Seeds of Artemisia aucheri Boiss 
Background
Artemisia aerial parts are well known for antimicrobial activities including anti malaria.
Objectives
This study was carried out to evaluate the antimicrobial activity and chemical composition of essential oil from the seeds of Artemisia aucheri Boiss (Asteraceae).
Materials and Methods
Essential oil was extracted from the powdered seeds of Artemisia aucheri by hydrodistillation. Antimicrobial activity against five bacterial species was tested using the disc diffusion method, and the chemical composition of the essential oil was analyzed by gas chromatography-mass spectrometry (GC-MS).
Results
The essential oil of Artemisia aucheri seed showed activity against Escherichia coli, Staphylococcus aureus, and Listeria monocytogenes. The essential oil constituents identified by GC-MS were as follows: decane, ρ-cymene, 1,8-cineole, linalool, ρ-mentha-8-ol, triene, borneol, lavandulol, bornyl acetate, chrysanthenyl acetate, dehydro aromadenderene, and caryophyllene oxide. Most of these compounds are also found in the aerial parts of Artemisia aucheri.
Conclusions
Variation in the compositions of essential oils from Artemisia aucheri, and thus variation in the antimicrobial activity of these oils, may be due to the plant parts used for essential oil prepration.
PMCID: PMC3941861  PMID: 24624145
Artemisia aucheri; Essential Oil; Antimicrobial Activity; Seed; Chemical Composition
14.  Cambial activity related to tree size in a mature silver-fir plantation 
Annals of Botany  2011;108(3):429-438.
Background and Aims
Our knowledge about the influences of environmental factors on tree growth is principally based on the study of dominant trees. However, tree social status may influence intra-annual dynamics of growth, leading to differential responses to environmental conditions. The aim was to determine whether within-stand differences in stem diameters of trees belonging to different crown classes resulted from variations in the length of the growing period or in the rate of cell production.
Methods
Cambial activity was monitored weekly in 2006 for three crown classes in a 40-year-old silver-fir (Abies alba) plantation near Nancy (France). Timings, duration and rate of tracheid production were assessed from anatomical observations of the developing xylem.
Key Results
Cambial activity started earlier, stopped later and lasted longer in dominant trees than in intermediate and suppressed ones. The onset of cambial activity was estimated to have taken 3 weeks to spread to 90 % of the trees in the stand, while the cessation needed 6 weeks. Cambial activity was more intense in dominant trees than in intermediate and suppressed ones. It was estimated that about 75 % of tree-ring width variability was attributable to the rate of cell production and only 25 % to its duration. Moreover, growth duration was correlated to tree height, while growth rate was better correlated to crown area.
Conclusions
These results show that, in a closed conifer forest, stem diameter variations resulted principally from differences in the rate of xylem cell production rather than in its duration. Tree size interacts with environmental factors to control the timings, duration and rate of cambial activity through functional processes involving source–sink relationships principally, but also hormonal controls.
doi:10.1093/aob/mcr168
PMCID: PMC3158687  PMID: 21816842
Cambial activity; forest-stand structure; silver fir (Abies alba); tree-ring formation; tree-to-tree competition; social status; wood anatomy; xylem cell differentiation
15.  Rosmarinus officinalis essential oil: antiproliferative, antioxidant and antibacterial activities 
Brazilian Journal of Microbiology  2010;41(4):1070-1078.
The aim of this work was to investigate and compare the antiproliferative, antioxidant and antibacterial activities of Rosmarinus officinalis essential oil, native to Pakistan. The essential oil content from the leaves of R. officinalis was 0.93 g 100g-1. The GC and GC-MS analysis revealed that the major components determined in R. officinalis essential oil were 1,8-cineol (38.5%), camphor (17.1%), α-pinene (12.3%), limonene (6.23%), camphene (6.00%) and linalool (5.70%). The antiproliferative activity was tested against two cancer (MCF-7 and LNCaP) and one fibroblast cell line (NIH-3T3) using the MTT assay, while, the antioxidant activity was evaluated by the reduction of 2, 2-diphenyl-1-picryl hydrazyl (DPPH) and measuring percent inhibition of peroxidation in linoleic acid system. The disc diffusion and modified resazurin microtitre-plate assays were used to evaluate the inhibition zones (IZ) and minimum inhibitory concentration (MIC) of R. officinalis essential oil, respectively. It is concluded from the results that Rosmarinus officinalis essential oil exhibited antiproliferative, antioxidant and antibacterial activities.
doi:10.1590/S1517-838220100004000027
PMCID: PMC3769777  PMID: 24031588
Antibacterial; Antioxidant; antiproliferative; 1,8-cienol; Resazurin assay
16.  Analysis of antimicrobial, antifungal and antioxidant activities of Juniperus excelsa M. B subsp. Polycarpos (K. Koch) Takhtajan essential oil 
Pharmacognosy Research  2010;2(3):128-131.
Juniperus excelsa M.B subsp. Polycarpos (K.Koch), collected from south of Iran, was subjected to hydrodistillation using clevenger apparatus to obtain essential oil. The essential was analyzed by gas chromatography/mass spectrometry (GC/MS) and studied for antimicrobial, antifungal and antioxidant activities. The results indicated α-pinene (67.71%) as the major compound and α-cedral (11.5%), δ3-carene (5.19%) and limonene (4.41%) in moderate amounts. Antimicrobial tests were carried out using disk diffusion method, followed by the measurement of minimum inhibitory concentration (MIC). All the Gram positive and Gram negative bacteria were susceptible to essential oil. The oil showed radical scavenging and antioxidant effects.
doi:10.4103/0974-8490.65505
PMCID: PMC3141302  PMID: 21808554
Antimicrobial activity; antioxidant activity; essential oil; Juniperus excelsa; thin layer chromatography autographic assay
17.  α-Pinene Rich Volatile Constituents of Cupressus torulosa D. Don from Uttarakhand Himalaya 
The aim of the present study was to investigate the various chemical components present in the volatile oil of the leaf of Cupressus torulosa and to find variation of essential oil components among the populations. Twenty-two, 17 and 20 compounds were identified with 95.45, 95.45 and 91.45% in Kalsi, Joshimath and Jeharikhal, respectively were identified by gas chromatography-mass spectrometry and quantify by gas chromatography and flame ionization detector (GC-FID). The major compound identified was α-pinene in all the populations and it varied between 30.30 and 34.26%. Results of the study stated that α-pinene, δ- 3-carene, limonene and sabinene components were detected in high concentration, thus competent for use in related industries and as a favourite ornamental aromatic tree.
doi:10.4103/0250-474X.106078
PMCID: PMC3574543  PMID: 23440249
α-pinene gas chromatography; Cupressus torulosa; gas chromatography-mass spectrometry; variation; volatile oil
18.  Essential Oils from Different Plant Parts of Eucalyptus cinerea F. Muell. ex Benth. (Myrtaceae) as a Source of 1,8-Cineole and Their Bioactivities 
Pharmaceuticals  2011;4(12):1535-1550.
Eucalyptus cinerea, known as silver dollar tree, has few descriptions in traditional medicine. Chemical composition and antimicrobial properties of the essential oils of leaves, flowers and fruits, collected seasonally, were determined by GC/MS and disk diffusion/MIC, respectively. 1,8-Cineole was the main compound, particularly in fresh leaves—Spring (74.98%), dried leaves—Spring (85.32%), flowers—Winter (78.76%) and fruits—Winter (80.97%). Other compounds were found in the aerial parts in all seasons: α-pinene (2.41% to 10.13%), limonene (1.46% to 4.43%), α-terpineol (1.73% to 11.72%), and α-terpinyl acetate (3.04% to 20.44%). The essential oils showed antimicrobial activities against bacteria and yeasts, with the best results being found for the dried autumn and winter leaves oils (MIC < 0.39 mg/mL) against Streptococcus pyogenes. For the other tested microorganisms the following MIC results were found: Staphylococcus aureus— Dried leaves oil from summer (0.78 mg/mL), Pseudomonas aeruginosa—Flowers oil from autumn and fruits oil from winter (1.56 mg/mL) and Candida albicans—Flowers oil from autumn and fruits oils from winter and spring (0.78 mg/mL).
doi:10.3390/ph4121535
PMCID: PMC4060100
Eucalyptus cinerea; essential oil; 1,8-cineole; seasonal variation; antimicrobial properties
19.  Antioxidant Activity of the Essential Oil and Methanolic Extract of Teucrium orientale (L.) subsp. taylori (Boiss.) Rech. f. 
This study was designed to examine the chemical composition and in-vitro antioxidant activity of the essential oil and methanolic extract of Teucrium orientale subsp. taylori. The GC and GC–MS analysis of the essential oil resulted in determination of 40 components representing 96.4% of the oil. The major constituents of the oil were linalool (28.6%), caryophyllene oxide (15.6%), 1,8-cineol (4.5%), β-pinene (8.7%), 3-octanol (9.5%), β-caryophyllene (7.3%), and germacrene-D (4.1%). Antioxidant activities of the samples were determined by two different tests, namely DPPH and β-carotene- linoleic acid assay. In DPPH system, the weakest radical scavenging activity was exhibited by the non-polar sub fraction of methanolic extract (237.40 ± 2.1 μg/mL). Antioxidant activity of the polar sub fraction of methanolic extract was superior to all samples tested, showing an EC50 value of 61.45 ± 0.5 μg/ mL. The inhibition capacity (%) of the polar sub fraction of methanolic extract (95.21% ± 1.3) was found to be the strongest and almost equal to the inhibition capacity of the positive control BHT (94.9% ± 1.1). The amount of the total phenolics was the highest in the polar subfraction, i.e. 370 μg/mg of the dry extract (37%). A positive correlation was observed between the antioxidant activity and the total phenolics of the extracts.
PMCID: PMC3870066  PMID: 24381607
Teucrium orientale subsp. Taylori; Essential oil; Antioxidant activity
20.  In Vitro Control of Post-Harvest Fruit Rot Fungi by Some Plant Essential Oil Components 
Eight substances that are main components of the essential oils from three Mediterranean aromatic plants (Verbena officinalis, Thymus vulgaris and Origanum vulgare), previously found active against some phytopathogenic Fungi and Stramenopila, have been tested in vitro against five etiological agents of post-harvest fruit decay, Botrytis cinerea, Penicillium italicum, P. expansum, Phytophthora citrophthora and Rhizopus stolonifer. The tested compounds were β-fellandrene, β-pinene, camphene, carvacrol, citral, o-cymene, γ-terpinene and thymol. Citral exhibited a fungicidal action against P. citrophthora; carvacrol and thymol showed a fungistatic activity against P. citrophthora and R. stolonifer. Citral and carvacrol at 250 ppm, and thymol at 150 and 250 ppm stopped the growth of B. cinerea. Moreover, thymol showed fungistatic and fungicidal action against P. italicum. Finally, the mycelium growth of P. expansum was inhibited in the presence of 250 ppm of thymol and carvacrol. These results represent an important step toward the goal to use some essential oils or their components as natural preservatives for fruits and foodstuffs, due to their safety for consumer healthy and positive effect on shelf life extension of agricultural fresh products.
doi:10.3390/ijms13022290
PMCID: PMC3292023  PMID: 22408454
fungitoxic activity; monoterpenes; plant essential oils; post-harvest diseases
21.  Enhancement of the antibiotic activity of erythromycin by volatile compounds of Lippia alba (Mill.) N.E. Brown against Staphylococcus aureus 
Pharmacognosy Magazine  2011;7(28):334-337.
Background:
Lippia alba (Mill.) N.E. Brown, popularly known as “erva-cidreira,” is commonly found in northeastern Brazil. The leaves tea is used to treat digestive disturbances, nausea, cough, and bronchitis.
Objective:
This work reports the chemical composition and erythromycin-modifying activity by gaseous contact against Staphylococcus aureus.
Materials and Methods:
The leaves of L. alba were subjected to hydrodistillation, and the essential oil extracted was examined with respect to the chemical composition, by gas chromatography-mass spectrometry (GC-MS), and the essential oil extracted was evaluated for antibacterial and antibiotic-modifying activity by gaseous contact.
Results:
The overall yield of essential oil obtained by hydrodistillation was 0.52%. The GC-MS analysis has led to the identification of the main components: geranial (31.4%) and neral (29.5%). It was verified that the essential oil interfered with erythromycin antibiotic activity against S. aureus ATCC 25923 was enhanced (221.4%) in the presence of 12% essential oil. The 3% essential oil increased the effect against S. aureus ATCC 25923 (41.6%) and S. aureus ATCC 6538 (58.3%). Conclusion: The essential oil of L. alba influences the activity of erythromycin and may be used as an adjuvant in antibiotic therapy against respiratory tract bacterial pathogens.
Conclusion:
The essential oil of L. alba influences the activity of erythromycin and may be used as an adjuvant in antibiotic therapy against respiratory tract bacterial pathogens.
doi:10.4103/0973-1296.90415
PMCID: PMC3261068  PMID: 22262937
Chemical composition; erythromycin; essential oil; Lippia alba; modulatory activity
22.  Participation of the GABAergic system in the anesthetic effect of Lippia alba (Mill.) N.E. Brown essential oil 
The objective of this study was to identify the possible involvement of the GABAergic system in the anesthetic effect of Lippia alba essential oil (EO). We propose a new animal model using silver catfish (Rhamdia quelen) exposed to an anesthetic bath to study the mechanism of action of EO. To observe the induction and potentiation of the anesthetic effect of EO, juvenile silver catfish (9.30 ± 1.85 g; 10.15 ± 0.95 cm; N = 6) were exposed to various concentrations of L. alba EO in the presence or absence of diazepam [an agonist of high-affinity binding sites for benzodiazepinic (BDZ) sites coupled to the GABAA receptor complex]. In another experiment, fish (N = 6) were initially anesthetized with the EO and then transferred to an anesthetic-free aquarium containing flumazenil (a selective antagonist of binding sites for BDZ coupled to the GABAA receptor complex) or water to assess recovery time from the anesthesia. In this case, flumazenil was used to observe the involvement of the GABA-BDZ receptor in the EO mechanism of action. The results showed that diazepam potentiates the anesthetic effect of EO at all concentrations tested. Fish exposed to diazepam and EO showed faster recovery from anesthesia when flumazenil was added to the recovery bath (12.0 ± 0.3 and 7.2 ± 0.7, respectively) than those exposed to water (9.2 ± 0.2 and 3.5 ± 0.3, respectively). In conclusion, the results demonstrated the involvement of the GABAergic system in the anesthetic effect of L. alba EO on silver catfish.
doi:10.1590/S0100-879X2012007500052
PMCID: PMC3854290  PMID: 22473320
False-melissa; Silver catfish; Benzodiazepines; Flumazenil; GABA
23.  In Vitro Cytotoxic Potential of Essential Oils of Eucalyptus benthamii and Its Related Terpenes on Tumor Cell Lines 
Eucalyptus L. is traditionally used for many medicinal purposes. In particular, some Eucalyptus species have currently shown cytotoxic properties. Local Brazilian communities have used leaves of E. benthamii as a herbal remedy for various diseases, including cancer. Considering the lack of available data for supporting this cytotoxic effect, the goal of this paper was to study the in vitro cytotoxic potential of the essential oils from young and adult leaves of E. benthamii and some related terpenes (α-pinene, terpinen-4-ol, and γ-terpinene) on Jurkat, J774A.1 and HeLa cells lines. Regarding the cytotoxic activity based on MTT assay, the essential oils showed improved results than α-pinene and γ-terpinene, particularly for Jurkat and HeLa cell lines. Terpinen-4-ol revealed a cytotoxic effect against Jurkat cells similar to that observed for volatile oils. The results of LDH activity indicated that cytotoxic activity of samples against Jurkat cells probably involved cell death by apoptosis. The decrease of cell DNA content was demonstrated due to inhibition of Jurkat cells proliferation by samples as a result of cytotoxicity. In general, the essential oils from young and adult leaves of E. benthamii presented cytotoxicity against the investigated tumor cell lines which confirms their antitumor potential.
doi:10.1155/2012/342652
PMCID: PMC3356891  PMID: 22645627
24.  Effect of Laurus nobilis L. Essential Oil and its Main Components on α-glucosidase and Reactive Oxygen Species Scavenging Activity 
The present study was designed to determine the effects of the essential oil of Laurus nobilis L. (Lauraceae) and its three main components on α-glucosidase and reactive oxygen species scavenging activity. The chemical composition of the essential oil from Laurus nobilis L. leaves was analyzed by GC/GC-MS and resulted in the identification of 29 compounds, representing 99.18% of the total oil. 1,8-cineole (68.82%), 1-(S)-α-pinene (6.94%), and R-(+)- limonene (3.04%) were determined to be the main components. The antioxidant features of the essential oil and its three main components were evaluated using inhibition of 2,2-diphenyl-1- picrylhydrazyl, hydroxyl, and superoxide radicals, inhibition of hydrogen peroxide and lipid peroxidation assays. The results show that the DPPH, hydroxyl, and superoxide radical as well as hydrogen peroxide scavenging activities of the essential oil are greater than the positive controls and the three main components of the oil when tested independently. The inhibition of lipid peroxidation by the oil occurred less frequently than with 1,8-cineole and R-(+)- limonene alone, but the effects were more pronounced than those seen with 1-(S)-α-pinene and the positive controls. An α-glucosidase inhibition assay was applied to evaluate the in-vitro antidiabetic activity of the essential oil. IC50-values were obtained for laurel essential oil, 1, 8-cineole, 1-(S)-α-pinene, and R-(+)-limonene: 1.748 μL/mL, 1.118 μL/mL, 1.420 μL/mL and 1.300 μL/mL, respectively. We also found that laurel essential oil and 1, 8-cineole inhibited the α-glucosidase competitively while 1-(S)-α-pinene and R-(+)-limonene were uncompetitive inhibitors.
PMCID: PMC3813252  PMID: 24250611
α-glucosidase; 1; 8-cineole; 1-(S)-α-pinene; Essential oil; Laurus nobilis L.; R-(+)-limonene
25.  Chemical composition and larvicidal activity of essential oil of Cupressus arizonica E.L. Greene against malaria vector Anopheles stephensi Liston (Diptera: Culicidae) 
Pharmacognosy Research  2011;3(2):135-139.
Background
Using botanical insecticides as an alternative biocontrol technique for vector control is considered by some scientists.
Materials and Methods
Chemical composition of the essential oil was analyzed using gas chromatography–mass spectrometry (GC–MS). In addition, the mosquito larvicidal activity of leaf essential oil of Cupressus arizonica was investigated against fourth instar larvae of laboratory-reared An. stephensi according to the method of the World Health Organization.
Results
Of 46 constituents in the oil, limonene (14.44%), umbellulone (13.25%) and α-pinene (11%) were determined as the main constituents. Cupressus arizonica volatile oil showed significant larvicidal activity against An. stephensi with LC50 and LC90 values 79.30 ppm and 238.89 ppm respectively. Clear dose-response relationships were established with the highest dose of 160 ppm essential oil with almost 100% mortality.
Discussion
The results from this study revealed that C. arizonica essential oil could be considered as a natural larvicide against An. stephensi. However, the field evaluation of the formulation is necessary.
doi:10.4103/0974-8490.81962
PMCID: PMC3129023  PMID: 21772758
Anopheles stephensi; botanical insecticide; Cupressus arizonica; essential oil; Iran; vector control

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