Ocotea quixos Lam. essential oil: In vitro and in vivo investigation on its anti-inflammatory properties

Here we investigated the anti-inflammatory properties of Ocotea quixos essential oil and of its main components, trans-cinnamaldehyde and methyl cinnamate, in in vitro and in vivo models. Ocotea essential oil and trans-cinnamaldehyde but not methyl cinnamate significantly reduced LPS-induced NO release from J774 macrophages at non-toxic concentrations, inhibited LPS-induced COX-2 expression and increased forskolin-induced cAMP production. The essential oil (30–100 mg/kg os) and trans-cinnamaldehyde (10 mg/kg os) in carrageenan-induced rat paw edema showed anti-inflammatory effect without damaging gastric mucosa. In conclusion we provide the first evidence of a significant anti-inflammatory gastro-sparing activity of O.quixos essential oil.     

Plant-derived essential oils affecting settlement and oviposition of Bemisia tabaci (Genn.) biotype B on tomato

The silverleaf whitefly Bemisia tabaci (Genn.) biotype B (Hemiptera: Aleyrodidae) is an economically important pest of tomatoes Solanum lycopersicum (L.), causing irregular ripening on fruits and transmitting several plant pathogenic geminiviruses. The management of this pest is commonly based on repetitive spraying with synthetic pesticides, causing serious environmental damages and increase of resistance by insect population. In the present study, essential oils from the leaves of Artemisia camphorata Vill., Ageratum conyzoides L., Foeniculum vulgare Mill., Lippia alba (Mill.) N. E. Br., Plectranthus neochilus Schltr., and Tagetes erecta L. were investigated for their possible repellent and oviposition-deterrent effects against B. tabaci biotype B on tomato. In a multi-choice assay, P. neochilus essential oil was the most active repellent and oviposition deterrent. Essential oils of A. conyzoides and T. erecta significantly deterred the female B. tabaci biotype B from laying eggs on treated tomato leaflets compared with the control. (E)-Caryophyllene (30.67 %) and the monoterpenes α-pinene (15.02 %) and α-thujene (11.70 %) were identified as the major constituents of the essential oil of P. neochilus. Our findings demonstrated the potential of essential oil of P. neochilus and other oils in the reduction of settlement and oviposition of B. tabaci biotype B on tomato.     

Chemical composition and bioactivities of three Chrysanthemum essential oils against Tribolium confusum (du Val) (Coleoptera: Tenebrionidae)

Essential oils from three species of Chrysanthemum growing in Tunisia (C. coronarium, C. fuscatum, and C. grandiflorum) were first analyzed by gas chromatography (GC) and GC/mass spectrometry (MS) and then evaluated for toxicity and antifeeding action against Tribolium confusum. The essential oils obtained from leaves and flowers shared a similar qualitative composition, but the relative proportions of the constituents were quite different. The essential oil of C. grandiflorum was rich in sesquiterpenoids, while those of C. fuscatum and C. coronarium were rich in monoterpenoids. The main common constituents of all the essential oils were ??-pinene, myrcene, ??-humulene, ??-caryophylene, spathulenol, and caryophyllene oxide. The most effective essential oil was obtained from the leaves of C. grandiflorum, that inhibited the relative growth rate (?0.03?mg/mg/d), efficiency of conversion of ingested food (?50.69%), relative consumption rate, caused an antifeeding effect (66.43%) and a high mortality (80%) of T. confusum larvae. Topical application C. grandiflorum essential oil caused a significant insect mortality that attends 27% after 7?days of treatment. While essential oil from C. coronarium flowers has contact and fumigant toxicity with a mortality of 9 and 13%, respectively. Results analysis highlights a relationship between essential oils composition and insecticidal activity against T. confusum. The study showed that each essential oil has specific chemical composition and act differently according to the nature of attributed test. The use of essential oils from different Chrysanthemum species with different methods helps poor farmers who store small amounts of grains to preserve it against pest infestation.     

Chemical composition of Eucalyptus erythrocorys essential oils and evaluation of their herbicidal and antifungal activities

The chemical composition of essential oil isolated by hydrodistillation from the leaves of Tunisian Eucalyptus erythrocorys Linn. was analyzed by gas chromatography (GC) and gas chromatography–mass spectrometry (GC/MS). Fifteen compounds were identified, representing 97 % of total oil, which was found to be rich in oxygenated monoterpenes (66.7 %), particularly in 1,8-cineole (54.8 %). The yield and the physico-chemical properties of oil were determined. The study of antifungal activity revealed that E. erythrocorys essential oil significantly inhibited the growth of five plant pathogenic fungi especially Bipolaris sorikiniana and Botritys cinerea. Moreover, herbicidal properties of the oil, tested on Sinapis arvensis L. and Phalaris canariensis L. indicated that the E. erythrocorys oil completely inhibited the seed germination at high concentration (1.5 μl/ml), while at low doses (0.25, 0.5, 0.75, 1 μl/ml) the oil acted by decreasing and delaying the germination and inhibiting the seedling growth of all tested weeds.     

Toxicity and antitermite activity of the essential oils from Cinnamomum camphora, Cymbopogon nardus, Melaleuca cajuputi and Dipterocarpus sp. against Coptotermes curvignathus

Efficacy of four different essential oils against the subterranean termite, Coptotermes curvignathus Holmgren, was assessed in various bioassays. Laboratory results indicate that the highest termite mortality was found in Dipterocarpus sp. essential oil after 24 h (LC₅₀ = 1.62 %) and the lowest in Melaleuca cajuputi (LC₅₀ = 4.60 %). The wood consumption in the filter paper treated with Dipterocarpus sp. oil is also smaller than for the other three essential oils tested. However, the other three essential oils also inhibited termite susceptibility of the specimens. Dipterocarpus sp. (keruing oil) was the most effective insect antifeedant and repellent against C. curvignathus. The results suggest that essential oils might have some beneficial activity of economic value and are considered good candidates for the development of new chemicals (repellents or antifeedants) for termite control.     

Neuropharmacological activities of fruit essential oil from Litsea cubeba Persoon

Litsea cubeba (Lauraceae) is woody plant endemic to Taiwan that is traditionally used as a spice. In the current study, several behavioral analyses were performed to evaluate the neuropharmacological activity of the essential fruit oil of L. cubeba in ICR mice. Oral administration of 100, 300 and 500?mg/kg of L. cubeba fruit oil significantly prolonged pentobarbitone-induced mouse sleeping time by 20.0, 110.8, and 159.6?%, respectively. In addition, after administration of L. cubeba oil, mice significantly increased the time spent in the open arms and number of entries into the open arms of an elevated plus maze compared to saline-treated mice suggesting that L. cubeba oil has anxiolytic activity. A tail-flick test conducted after treatment of mice with 500?mg/kg L. cubeba fruit oil also suggested that this oil has potent analgetic activity. According to GC/MS analyses, the essential fruit oil of L. cubeba oil consists of 23 compounds. The main components are geranial (37.16?%), neral (28.29?%), and d-limonene (22.90?%). We conclude that L. cubeba oil has a potent effect on the central nervous system of mice.     

Essential oil of Lindera neesiana fruit: Chemical analysis and its potential use in topical applications

The composition of the essential oil of Lindera neesiana Kurz fruit was examined by GC-MS, ¹H, ¹³C and bidimensional NMR techniques (HMQC, HMBC, COSY, TOCSY). Forty compounds were identified, representing approximately 86% of the oil: Z-citral (15.08%), E-citral (11.89%), eucalyptol (8.75%), citronellal (6.72%), α-pinene (6.63%) and β-pinene (5.61%) were the major components. The essential oil of L. neesiana fruit showed significant antimicrobial activity against Staphylococcus aureus and Candida albicans at non-cytotoxic doses in human keratinocytes, suggesting possible topical applications.     

Composition and antimicrobial activity of <Emphasis Type="Italic">Cistus munbyi</Emphasis> essential oil: an endemic plant from Algeria

The chemical composition and antimicrobial potential of Cistus munbyi essential oil were studied for the first time. GC and GC–MS analysis revealed 48 compounds representing 96.98% of the oil. Terpinen-4-ol (23.75%), meta-Cymene (17.30%), and Sabinene (12.38%) were the major constituents. Antimicrobial activity was evaluated against nine pathogens using the disc diffusion and broth micro-dilution methods. Results show that C. munbyi essential oil possesses strong antimicrobial activity against all strains, regardless if Gram-positive or Gram-negative bacteria, or yeast, with MICs values not exceeding 10 (mg/ml). In addition to its efficacy, C. munbyi essential oil has an unusual antimicrobial potency which is attributed to its specific chemical composition. Thus, findings presented here suggest that endemic C. munbyi contains a very interesting essential oil that may be valuable in several areas.     

Effect of essential oils of some medicinal plants on phytonematodes

The essential oils of four medicinal plants belonging to Lamiaceae were explored for phytonematode control. The four oils inhibited (P<0.05) nematode motility butMentba spicata was generally more effective in reducing the numbers of active nematodes followed byThymus vulgaris, Majorana bortensis andMentba longifolia. The main corresponding compound of each oil, determined by GLC analysis, was carvone (58.14%), P-cymene (40.5%), terpinen-4-ol (41.6%) and carvone (70.36%). Soil stages of the reniform nematode were more affected by the oil than those of the ring and lance nematodes. When transferred to water, the total nematodes that regained their activeness ranged from 12% forT. vulgaris to 60% forM. longifolia. The four 0.1 oil solutions inhibited more than to about 3.5% at the control. The content of oxygenated compounds in these oils ranged from 45.79% to 96.5% and may be partially responsible for the nematicidal effects.     

双斑长跗萤叶甲对几种植物挥发物的触角电位和行为反应

采用触角电位(EAG)、"Y"型嗅觉仪和风洞的方法研究双斑长跗萤叶甲成虫对14种植物挥发物的电生理和行为反应,筛选出对双斑长跗萤叶甲有效的植物挥发物,为该害虫的种群监测和防控提供新技术。研究结果表明:稀释102、103倍的薄荷精油和1 mol.L-1的香叶醇能引发双斑长跗萤叶甲强烈的EAG反应(P<0.01),且嗅觉测试表明,薄荷精油(稀释102倍)对双斑长跗萤叶甲的最大驱避率为(74±5.47)%,香叶醇(1 mol.L-1)对双斑长跗萤叶甲的最大引诱率为(70±10.00)%。风洞行为趋性研究表明:稀释102倍的薄荷精油对双斑长跗萤叶甲的最大驱避率为(72±8.37)%,而1 mol.L-1的香叶醇对双斑长跗萤叶甲的最佳引诱率为(66±8.94)%。     

Chemical composition and anti-inflammatory activity of <Emphasis Type="Italic">Boswellia ovalifoliolata</Emphasis> essential oils from leaf and bark

We isolated the essential oils from Boswellia ovalifoliolata N.P.Balakr and A.N.Henry using hydrodistillation, identified the obtained compounds using gas chromatography–mass spectrometry (GC–MS) and Fourier transform-infrared spectroscopy (FT-IR), and studied the photophysical and electrochemical properties using UV–visible and fluorescence spectroscopy and cyclic voltammetry. On the basis of GC–MS spectra, 38 compounds were identified in the essential oil from leaves and 26 in the oil from bark. The bark oil contained 13.44% β-Farnesene (sesquiterpene), 10.45% caryophyllene oxide (sesquiterpene) and 6.6% spathulenol, (2Z,6E)-(sesquiterpene alcohol); the leaf oil contained 11.1% spathulenol (sesquiterpene alcohol), 9.0% caryophyllene oxide (sesquiterpenoids) and 6.3% decyl acetate (ester). FT-IR spectra confirmed the presence of aliphatic aldehydes and ketones, carboxylic acid, alcohols, esters and ethers in both oil types. UV–visible absorption spectra showed maximum absorbance at 245, 290 and 402 nm for bark oil, and 250, 285 and 325 nm for leaf. Bark oil showed strong emission with maximum emission wavelength at 456 nm was higher than that of leaf oil at 414 nm. The essential oil had significant anti-inflammatory activity, and the reduction potential of the leaf oil was ?0.44 and ?0.56 eV for bark.     

Phytochemical analysis,biological evaluation and micromorphological study of Stachys alopecuros (L.) Benth. subsp. divulsa (Ten.) Grande endemic to central Apennines,Italy

Stachys alopecuros subsp. divulsa (Lamiaceae), a perennial herb endemic to central Italy growing on mountain pastures, was investigated for the first time for the content of secondary metabolites, for the micromorphology and histochemistry of glandular trichomes, and for the biological activity of the volatile oil, namely cytotoxic, antioxidant and antimicrobial. The plant showed the molecular pattern of iridoids, among which a new iridoid diglycoside (4′-O-β-d-galactopyranosyl-teuhircoside) was detected, together with a sterol glucoside and a phenylethanoid glycoside. The essential oil from the flowering aerial parts was characterized by a high proportion of sesquiterpene hydrocarbons (65.1%), with (E)-caryophyllene (33.2%) as the most abundant, while other main components were germacrene D (7.6%), α-humulene (6.4%) and the oxygenated cis-sesquisabinene hydrate (10.2%). Taken together, polar and apolar chemical profiles support the classification of the species within the section Betonica of the genus Stachys. Micromorphological study revealed three types of glandular hairs secreting different classes of compounds, with type A peltate hairs producing the bulk of the essential oil. MTT assay revealed the potential of the volatile oil in inhibiting A375, HCT116 and MDA-MB 231 tumor cells (IC₅₀ values below 20 μg/ml).     

MA-chitosan nanogel loaded with Cuminum cyminum essential oil for efficient management of two stored product beetle pests

Natural essential oils have received increased attention as alternatives to synthetic pesticides for pest management of foodstuffs. Recently, microencapsulation and other controlled release techniques are used to increase insecticidal efficiency and persistence of essential oils with slow and controlled release. In this study, the possibility of improving the insecticidal activity of plant essential oils was investigated for effective management of two stored product beetle pests. Self-assembly technique was used to prepare nanogels of myristic acid-chitosan loaded by essential oil extracted from cumin, Cuminum cyminum L. Fumigant toxicity of C. cyminum oil and oil-loaded nanogels (OLNs) were investigated at 4, 7, 10, 13, and 16 µL/L air against the granary weevil Sitophilus granarius L. and 8, 11, 14, 17, and 20 µL/L air for confused flour beetle Tribolium confusum Jacquelin du Val. Experiments were conducted at 27 ± 1 °C and 55 ± 5 % relative humidity in continuous darkness. Insecticidal bioassay revealed that OLNs were more toxic than C. cyminum oil against tested beetle pests. The persistence of the oil and OLNs was also evaluated against two tested species. Results indicated that C. cyminum oil completely lost its insecticidal activity after 12 days, whereas at the same period, the OLNs lost about 60 % of its activity when applied against S. granarius and 15% for T. confusum. Therefore, it could be concluded that encapsulation improved the persistence of the oil.     

Heartwood assessment of natural <Emphasis Type="Italic">Santalum album</Emphasis> populations for agroforestry development in Sri Lanka

Sandalwood (Santalum album) is developing as an important agroforestry crop in Sri Lanka. The value of S. album depends upon the oil content in the heartwood and its composition with reference to sesquiterpene alcohols cis-α-santalol and cis-β-santalol. According to the popular belief in Sri Lanka, certain S. album trees do not produce oil even after maturity. Therefore the present study was conducted to identify the presence and the variation of essential oil, its composition and the variation of growth parameters of nine distinctive S. album populations growing under different agroecological zones in Sri Lanka. According to the results, heartwood content, oil content and its constituents varied within and between the populations. It was interesting to observe that cis-α-santalol and cis-β-santalol were not detected in certain S. album trees though the oil contents of those trees were higher than the average. Heartwood content of the trees did not show a correlation with oil content, dbh and height. However, the oil content was significantly correlated with tree dbh and height. Majority of the trees (62 %) had heartwood essential oil in compliance to ISO standards; only a 31 % of the total sampled trees had the essential oil content above 2 % (w/w). Dry mountainous Badulla district had the highest percentage of trees complying the ISO standards. These findings are vital for identifying suitable sources for agroforestry propagation of S. album.     

Chemical analysis of essential oils of Eupatorium adenophorum and their antimicrobial,antioxidant and phytotoxic properties

Essential oils from inflorescences and roots of Eupatorium adenophorum Spreng (Asteraceae) have been investigated for their antimicrobial, phytotoxic and antioxidant activities. Based on GC–MS, the oil from inflorescences is dominated by sesquiterpenes (55.9 %) with γ-cadinene (18.4 %), γ-muurolene (11.7 %), 3-acetoxyamorpha-4,7(11)-diene-8-one (7.4 %) and bornyl acetate (6.3 %) as the major constituents. The oil obtained from the roots contained both sesquiterpenes (34.3 %) and monoterpenes (32.5 %) in almost equal proportions with E,E-cosmene (19.9 %), γ-muurolene (10.1 %), isothymol (7.5 %), β-cadinene (7.0 %) and α-phellandren-8-ol (5.9 %) as the major constituents. Both oils exhibited significant antifungal activity against five phytopathogenic fungi. The inflorescence oil showed higher antibacterial activity against Klebsiella pneumoniae, while the root oil was more effective against Staphylococcus aureus. The oils strongly inhibited or delayed germination and seedling growth of the weed Phalaris minor in a dose-dependent manner. As evidenced by a DPPH assay, the essential oils also exhibited significant free radical scavenging activity.     

Essential oil content and composition of Indian sandalwood (Santalum album) in Sri Lanka

Santalum album (Indian Sandalwood) is found in the mountainous regions of the intermediate zone of Sri Lanka. Few studies have been conducted on sandalwood ecology in this region, and ours is the first recorded study of essential oil content and chemical composition of heartwood. We harvested two trees with State permission and took crosssections for analysis. We demonstrated a difference in the heartwood formation and oil yield of the trees. The composition of the oil was found to be consistent between trees and along the trunk of the tree. Main aromatic compounds were santalols and other compounds are recorded in lesser quantities. Results of this study comply with the other published work on sandalwood elsewhere. This initial study on S. album in Sri Lanka provided promising results for the future of sandalwood agro- forestry.     

Contact,fumigant, and cytotoxic activities of thyme and lemongrass essential oils against larvae and an ovarian cell line of the cabbage looper,Trichoplusia ni

The chemical composition of a plant essential oil can be affected by many environmental and biological factors. Understanding the role of individual constituents as well as their interactions to the overall insecticidal bioactivity is prerequisite to the use of essential oils as an alternative to conventional insecticides. In the present study, the chemical compositions of plant essential oils obtained from Thymus vulgaris (thyme) and Cymbopogon citratus (lemongrass) were analyzed by gas chromatography/mass spectrometry, and the insecticidal and cytotoxic activities of individual constituents were evaluated against third instar larvae and an ovarian cell line of Trichoplusia ni. Thymol was the most abundant compound in thyme oil and the primary active constituent in contact and cytotoxicity tests, whereas p-cymene was the most effective compound for fumigant toxicity. In lemongrass oil, citral was identified as the major active and most abundant constituent. A weak correlation between insecticidal activity and cytotoxicity was observed, indicating limitation of the latter as a screening tool for novel insecticides. Although the evaporation of thymol was enhanced at higher temperatures, its contribution to fumigant activity was limited.     

The aromatic and polyphenolic composition of lemon verbena tea

The chemical composition of the largely used tea from lemon verbena, Aloysia triphylla, was investigated. The qualitative and quantitative composition of the main aromatic and polyphenolic constituents of tea made by infusion from leaves were examined. The results showed that the relative proportions of the active constituents differ from those of the original leaves. The tea contained a large amount of polyphenolic compounds (mean value 675 mg/l; extraction yield 65%) including verbascoside (400 mg/l) and luteolin 7-diglucuronide (100 mg/l). It contained also 42 mg/l of essential oil (extraction yield 51%) with much more citral (77% of the essential oil) than the original leaves (41%).     

Antifungal activity of essential oils isolated from Egyptian plants against wood decay fungi

The essential oils of eighteen Egyptian plants were extracted by hydrodistillation and their chemical compositions were analyzed by GC-MS. The antifungal activity of the isolated oils was evaluated against two wood decay fungi Hexagonia apiaria and Ganoderma lucidum in vitro. The essential oil of Artemisia monosperma showed the highest inhibitory effect against H. apiaria (EC₅₀ = 31 mg L^?1) and G. lucidum (EC₅₀ = 53 mg L^?1). The results of in vitro tests indicated that the essential oils of Cupressus sempervirens, Citrus limon, Thuja occidentalis, Schinus molle, A. monosperma and Pelargonium graveolens were the most potent inhibitors against both fungi. These six oils caused significant reduction of wood mass loss of Scots pine sapwood after 6 weeks of fungal exposure. The oil of C. limon revealed the highest reduction of wood mass loss caused by H. apiaria, while A. monosperma oil displayed the highest reduction of wood loss caused by G. lucidum. These results support the potential use of essential oils for wood protection against decay fungi.     

Cleome hirta essential oil as livestock tick (Rhipicephalus appendiculatus) and maize weevil (Sitophilus zeamais) repellent

The repellency of the essential oil of the shrub Cleome hirta and of three identified constituents (phytol, (+)-cedrol, n-octacosane) was evaluated against the livestock tick, Rhipicephalus appendiculatus and the maize weevil, Sitophillus zeamais. In a tick climbing repellency bioassay, the oil exhibited repellency which, at the highest dose, was comparable to that of the commercial arthropod repellent N,N-diethyltoluamide (DEET). In a Y-tube olfactometer bioassay, the oil showed higher or comparable repellency against S. zeamais relative to DEET at all the doses tested. The potential of C. hirta in livestock tick and maize weevil control is discussed.