Phytochemical composition of Cymbopogon citratus and Eucalyptus citriodora essential oils and their anti-inflammatory and analgesic properties on Wistar rats

Cymbopogon citratus and Eucalyptus citriodora are widely used herbs/plants as a source of ethnomedicines in tropical regions of the world. In this work, we studied the anti-inflammatory and gastroprotective effects of C. citratus and E. citriodora essential oils on formol-induced edema, and acetic acid induced abdominal cramps in Wistar rats. To fully understand the chemically induced anti-inflammatory properties of these plants, we first analyzed the chemical composition of the essential oils. A total of 16 chemical constituents accounting for 93.69 % of the oil, were identified in C. citratus among which, Geranial (27.04 %), neral (19.93 %) and myrcene (27.04 %) were the major constituents. For E. citriodora, 19 compounds representing 97.2 % of the extracted oil were identified. The dominant compound of E. citriodora essential oil was citronellal (83.50 %). In vivo analysis and histological assay showed that the two essential oils displayed significant dose dependent edema inhibition effect over time. They displayed strong analgesic and antipyretic properties similar to that induced by 50 mg/kg of acetylsalicylate of lysine. However, the E. citriodora essential oil was more effective than that of C. citratus. We identified significant numbers of aldehyde molecules in both essential oils mediating antioxidant activity that may contribute to the anti-inflammatory effects observed on the rats. Altogether, this work demonstrates the anti-inflammatory property of C. citratus and E. citriodora suggesting their potential role as adjuvant therapeutic alternatives in dealing with inflammatory-related diseases.     

Nematicidal Activity of Plant Essential Oils and Components From Ajowan (Trachyspermum ammi), Allspice (Pimenta dioica) and Litsea (Litsea cubeba) Essential Oils Against Pine Wood Nematode (Bursaphelenchus Xylophilus)

Commercial plant essential oils from 26 plant species were tested for their nematicidal activities against the pinewood nematode, Bursaphelenchus xylophilus. Good nematicidal activity against B. xylophilus was achieved with essential oils of ajowan (Trachyspermum ammi), allspice (Pimenta dioica) and litsea (Litsea cubeba). Analysis by gas chromatography-mass spectrometry led to identification of 12, 6 and 16 major compounds from ajowan, allspice and litsea oils, respectively. These compounds from three plant essential oils were tested individually for their nematicidal activities against the pinewood nematode. LC₅₀ values of geranial, isoeugenol, methyl isoeugenol, eugenol, methyl eugenol and neral against pine wood nematodes were 0.120, 0.200, 0.210, 0.480, 0.517 and 0.525 mg/ml, respectively. The essential oils described herein merit further study as potential nematicides against the pinewood nematode.     

Evaluation of chemical composition and anti-inflammatory,antioxidant, antibacterial activity of essential oil of Sardinian Santolina corsica Jord. & Fourr.

Santolina corsica Jord. & Fourr. Corsican-Sardinian is an endemism almost present all around Corsica; in Sardinia, it can only be found in Monte Albo (calcareous substratum and poor in nutrients). The aim of our study is to investigate the chemical composition of S. corsica essential oils from plants growing in three different stations located at different altitudes and evaluate the biological activity using anti-inflammatory, antioxidant and antimicrobial test. The composition of the essential oils was determined by gas chromatography and gas chromatography/mass spectrometry. The essential oils of the Sardinian-Corsican endemism S. corsica, growing in Monte Albo, showed a great variability, probably due to genetic characters different from the Corsican type. We found three different chemotypes: artemisia ketone-β-fellendrene; myrcene and β-fellandrene-myrcene. Standard microbiological assays demonstrated that the essential oils collected in the selected stations, compared with oil and compound with demonstrated antibacterial activity, don’t have any antibacterial activity. DPPH test carried out on the tree samples, compared with chatechin, demonstrated that the oils don’t have antioxidant activity.Regarding anti-inflammatory activity the study demonstrated that the essential oils have a good anti-inflammatory activity on the bronchial tract.The addition of essential oil make easy the exocytose and the histiocytes can expel the anthracotic pigment into the culture medium, purifying its cytoplasm and restoring its ability to phagocytize more material. With a higher concentration of granulocytes in the sample, the incubation of cells shows a non-specific inflammatory pattern in which the addition of the essential oils has a positive impact on the decrease of granulocytes.More experiments are requested to confirm the data, but on the basis of these first results S. corsica essential oil showed potential activity against respiratory infections.     

Effects of essential oil inhalation on objective and subjective sleep quality in healthy university students

Aromatherapy with essential oils is one of the most popular complementary medical tools for improving sleep quality. However, only a few reports have objectively measured the effects of essential oils on sleep. Here, we used objective and subjective measures to analyze the effects of the essential oils of lavender (Lavandula angustifolia) and sweet orange (Citrus sinensis) on the sleep quality of healthy university students. The participants were monitored for 15 consecutive nights as they inhaled lavender oil and sweet orange oil, in a crossover design. Their sleep was monitored objectively by actigraphy, and total sleep time (TST), sleep efficiency, sleep latency, and wake after sleep onset (WASO) were analyzed. Their sleep was analyzed subjectively using Oguri–Shirakawa–Azumi (OSA) sleep inventory scores. Inhalation of an essential oil improved sleep measures only in participant whose sleep quality was poor in the control condition. Lavender seemed more effective than sweet orange in objective measures, especially in improving sleep latency. In the subjective sleep analysis, the essential oils improved sleep maintenance, dreaming, and sleep length in subjects who had poor sleep quality. Sweet orange seemed more effective than lavender in the subjective sleep measures. The difference between the two oils suggests that expectancy bias had little effect on the hypnotic effect of lavender on objective sleep. Although no obvious effect was observed in good sleepers, the inhalation of lavender oil could be effective for helping poor sleepers improve objective sleep quality.

     

Essential oils and its bioactive compounds modulating cytokines: A systematic review on anti-asthmatic and immunomodulatory properties

BackgroundAsthma, the main inflammatory chronic condition affecting the respiratory system, is characterized by hyperresponsiveness and reversible airway obstruction, recruitment of inflammatory cells and excessive production of mucus. Cytokines as biochemical messengers of immune cells, play an important role in the regulation of allergic inflammatory and infectious airway processes. Essential oils of plant origin are complex mixtures of volatile and semi volatile organic compounds that determine the specific aroma of plants and are categorized by their biological activities.PurposeWe reviewed whether essential oils and their bioactive compounds of plant origin could modulate cytokines’ immune responses and improve asthma therapy in experimental systems in vitro and in vivo.MethodsElectronic and manual search of articles in English available from inception up to November 2018 reporting the immunomodulatory activity of essential oils and their bioactive compounds for the management of asthma. We used PubMed, EMBASE, Scopus and Web of Science. Publications reporting preclinical experiments where cytokines were examined to evaluate the consequence of anti-asthmatic therapy were included.Results914 publications were identified and 13 were included in the systematic review. Four articles described the role of essential oils and their bioactive compounds on bronchial asthma using cell lines; nine in vivo studies evaluated the anti-inflammatory efficacy and immunomodulating effects of essential oil and their secondary metabolites on cytokines production and inflammatory responses. The most important immunopharmacological mechanisms reported were the regulation of cytokine production, inhibition of reactive oxygen species accumulation, inactivation of eosinophil migration and remodeling of the airways and lung tissue, modulation of FOXP3 gene expression, regulation of inflammatory cells in the airways and decreasing inflammatory mediator expression levels.ConclusionPlant derived essential oils and related active compounds have potential therapeutic activity for the treatment of asthma by modulating the release of pro-inflammatory (TNF-α, IL-1β, IL-8), Th17 (IL-17), anti-inflammatory (IL-10), Th1 (IFN-γ, IL-2, IL-12) and Th2 (IL-4, IL-5, IL-6, IL-13) cytokines and the suppression of inflammatory cell accumulation.     

In vitro evaluation of the effects of some plant essential oils on Ascosphaera apis,the causative agent of Chalkbrood disease

Ascosphaera apis is one of the major fungal pathogens of honey bee broods and the causative agent of Chalkbrood disease. The factors responsible for the pathogenesis of Chalkbrood disease are still not fully understood, and the increasing resistance of A. apis to commonly used antifungal agents necessitates a search for new agents to control this disease. The in vitro antifungal activities of 27 plant essential oils against two isolates of A. apis (Aksu-4 and Aksu-9) were evaluated. Out of the 27 plant essential oils tested, 21 were found to be effective in killing both isolates of A. apis. Based on their minimum fungicidal concentration (MFC) values, the effective oils were grouped into three categories: highly effective, moderately effective and minimally effective. Mountain pepper oil, Kala Bhangra oil, spearmint oil, babuna oil, betel leaf oil, carrot seed oil, cumin seed oil and clove bud oil were highly effective, with MBC values between 50.0 μg/mL and 600.0 μg/mL. Mountain pepper was the most effective essential oil, with an MBC value of 50.0 μg/mL. Citral and caryophyllene containing oils were the most effective with MIC 50 ppm. The essential oils tested exhibited significant antimicrobial activities against both strains of A. apis, and they may contain compounds that could play an important role in the treatment or prevention of Chalkbrood disease of honeybee.     

Fumigant toxicity of Apiaceae essential oils and their constituents against Sitophilus oryzae and their acetylcholinesterase inhibitory activity

We evaluated the insecticidal and acetylcholinesterase (AChE) inhibition activities of the essential oils and their constituents of 10 Apiaceae on the adult rice weevil, Sitophilus oryzae. Of the 10 species tested, dill (Anethum graveolens), caraway (Carum carvi), and cumin (Cuminum cyminum) essential oils showed strong fumigant toxicity against adult S. oryzae. LC₅₀ values of caraway, dill, and cumin essential oils were 2.45, 3.29, and 4.75 mg/L air, respectively. Among the test compounds, (+)-carvone, (?)-carvone, cuminaldehyde, dihydrocarvone, linalool oxide, carveol, trans-anethole, and neral demonstrated strong fumigant toxicity against adult S. oryzae with LC₅₀ values of 0.61, 0.84, 1.12, 2.92, 3.76, 4.29, 5.02, and 6.60 mg/L air, respectively. α-Pinene showed the strongest AChE inhibition activity followed by β-pinene and limonene. The measured toxicity of the artificial blends of the constituents identified in dill and cumin oils indicated that (+)-carvone and cuminaldehyde were major contributors to the fumigant toxicity of the artificial blend.     

Chemical composition and antimicrobial activity of Citrus essences on honeybee bacterial pathogen <Emphasis Type="Italic">Paenibacillus larvae</Emphasis>, the causal agent of American foulbrood

Antimicrobial properties and chemical composition of four citrus fruit essential oils to control Paenibacillus larvae, the causal agent of American foulbrood disease (AFB) were determined. This honeybee larvae disease occurs throughout the world and is found in many beekeeping areas of Argentina. Citrus fruit essential oils tested were those from grapefruit (Citrus paradisi), sweet orange (Citrus sinensis), mandarin (Citrus nobilis) and lemon (Citrus limon). The components of the essential oils were identified by SPME-GC/MS analysis. The antimicrobial activity of the oils against P. larvae were determined by the broth microdilution method. Two way ANOVA tests for minimum inhibitory concentrations (MICs) data and minimal bactericide concentrations (MBCs) data, indicated significant differences between the strains and the oils tested. The antimicrobial assays showed that the oil of C. paradisi inhibited the bacterial strains at the lowest concentrations tested, MICs and MBCs averages of 385.0 mg/l and 770.0 mg/l, respectively. This property could be attributed to the kind and percentage of the volatile components of the oil, like limonene (69.9%) and myrcene (9.6%). The use of essential oils or their specific volatile components individually against pests related to food provision may represent an alternative scope for the control of this serious disease because it does not leave toxic chemical residues in honey nor in its by products.     

Essential oils of citrus fruit stimulate oviposition in the Mediterranean fruit fly Ceratitis capitata (Diptera: Tephritidae)

Female Mediterranean fruit flies (medfly) Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) perceive both qualitative and quantitative aspects of citrus fruit chemistry. However, the behavioural and biological adjustments of this response remain largely unknown. In the present study, the ovipositional responses of gravid female medflies to essential oils (i.e. the most critical resistance factor to medfly infestation) of various citrus fruits are investigated. In dual‐choice (treatment versus distilled water control) experiments, females lay significantly more eggs into pre‐punctured hollow oviposition hemispheres (domes) provided with 1 µL of citrus peel oil from sweet orange, satsuma mandarin, bitter orange, grapefruit and lemon compared with odourless domes. No‐choice tests show a weak effect of lemon essential oils in stimulating oviposition. The female ovipositional response to sweet orange oil (the most active in eliciting oviposition) is dose‐dependent. Additionally, limonene, the most abundant chemical in all citrus oils, stimulates oviposition, whereas linalool, a representative compound of immature citrus fruit associated with high toxicity against immature stages of fruit flies, has a significant deterrent effect. In further no‐choice tests, females lay approximately 23% fewer eggs in limonene (93%) (amount found in orange oil) and 60% fewer eggs in limonene 93% plus linalool 3% (approximately 10‐fold the amount found in orange oil) mixtures, relative to sweet orange oil. The results suggest that the limonene content accounts largely (but not completely) for the ovipositional responses observed in sweet orange oil, whereas high linalool proportions are capable of significantly masking and/or disrupting its stimulatory effects in citrus oils. The importance and practical implications of these findings with respect to understanding how citrus fruit chemistry influences the ovipositional responses of medfly is discussed.     

Evaluation of the composition and in vitro antimicrobial,antioxidant, and anti-inflammatory activities of Cilantro (Coriandrum sativum L. leaves) cultivated in Saudi Arabia (Al-Kharj)

BackgroundIn the present study, we explored the composition of Cilantro (Coriandrum sativum L. leaves) essential oil (CEO) cultivated in Saudi Arabia (Al-Kharj) and explored its antioxidant, antimicrobial, and anti-inflammatory effects in vitro.MethodsGas chromatography-mass spectroscopy was used to detect the CEO composition. The 2, 2-diphenyl-1-picrylhydrazyl (DPPH)-induced free radical and ferric chloride scavenging methods were used to determine the antioxidant activity. Antimicrobial activity was investigated using the well diffusion method. Anti-inflammatory activity was evaluated using egg albumin and trypsin-induced inflammation methods.ResultsForty-six compounds representing 90.17% of the total aroma were identified in the CEO; the major constituents were found to be 1-decanol (17.85%), decanal (11.04%), trans-2-dodecen-1-ol (7.87%), menthone (6.71%), 2-decen-1-ol, trans- (5.44%), dodecanal (4.76%), trans-tetradec-2-enal (3.14%), sedanolide (3.02), and thymol (3.01%). DPPH-induced free radical and ferric chloride scavenging assays demonstrated low antioxidant effects of CEO, and the antioxidant activity was observed at a high CEO concentration. The antimicrobial activity of CEO was assessed against 5 microorganisms (bacteria and fungi) by using well diffusion methods; CEO was found to possess excellent antimicrobial activity against all microorganisms, except Escherichia coli. Moreover, CEO demonstrated strong anti-inflammatory activity against egg albumin- and trypsin-induced inflammation.ConclusionThe essential oil extracted from C. sativum chemotype grown in Al-Kharj region of Saudi Arabia possesses low antioxidant potential, superior antimicrobial activity, and outstanding anti-inflammatory effects.     

Toxicity of citrus essential oils against Ceratitis capitata (Diptera: Tephritidae) larvae

Citrus peel essential oils are considered to constitute the most important resistance factor of citrus fruits against fruit flies. Essential oils were obtained from three sweet orange varieties, one bitter orange and one lemon variety. Yield, chemical composition and toxicity against neonates of the Mediterranean fruit fly were determined. Based on chemical analysis, the toxicity of commercially purchased major and minor components (monoterpenes and sesquiterpenes) of essential oils was determined. In addition, fractions were prepared to evaluate the role of minor components in the toxicity of crude essential oils. Limonene was by far the most abundant ingredient (96.2–97.4%) in all sweet orange varieties and in bitter orange, while the concentration of limonene was much lower in lemon essential oils (74.3%). Orange and bitter orange essential oils were more toxic than lemon essential oils. The toxicity of orange and bitter orange essential oils was similar to that of their major component limonene. In tests of commercially purchased chemicals, the oxygenated components of essential oils were more toxic than hydrocarbons but their low concentration in citrus essential oils could not affect the toxic activity of essential oils. The presence of α-pinene and β-pinene seems to account for the lower toxicity of lemon essential oils in relation to other citrus essential oils. The importance of understanding the toxicity of essential oils in relation to their composition and their role regarding the resistance of citrus fruits to Ceratitis capitata infestation is discussed.     

Design,synthesis, evaluation,and molecular docking of ursolic acid derivatives containing a nitrogen heterocycle as anti-inflammatory agents

Ursolic acid derivatives containing oxadiazole, triazolone, and piperazine moieties were synthesized in an attempt to develop potent anti-inflammatory agents. Structures of the synthesized compounds were elucidated by ¹H NMR, ¹³C NMR, and HRMS. Most of the synthesized compounds showed pronounced anti-inflammatory effects at 100?mg/kg. In particular, compound 11b, which displayed the most potent anti-inflammatory activity of all of the compounds prepared, with 69.76% inhibition after intraperitoneal administration, was more potent than the reference drugs indomethacin and ibuprofen. The cytotoxicity of the compounds was also assessed by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay, and no compounds showed any appreciable cytotoxic activity (IC₅₀ >100?μmol/L). Furthermore, molecular docking studies of the synthesized compounds were performed to rationalize the obtained biological results. Overall, the results indicate that compound 11b could be a therapeutic candidate for the treatment of inflammation.     

In vitro propagation, histochemistry, and analysis of essential oil from conventionally propagated and in vitro-propagated plants of Varronia curassavica Jacq

Varronia curassavica is cultivated for the production of an essential oil useful in the pharmaceutical industry for its strong anti-inflammatory effect. Despite a growing demand, only a few studies have evaluated alternative sources of obtaining plantlets or ways to increase the yield of essential oil from this species. Therefore, this study aimed to optimize the in vitro multiplication rate and analyze the histochemistry and sesquiterpene production potential of conventionally propagated V. curassavica plants, in vitro shoots, and acclimatized plants derived from in vitro shoots. For axillary bud proliferation, Murashige and Skoog medium was supplemented with 6-benzyladenine and thidiazuron alone or in combination with naphthalene acetic acid. Axillary bud proliferation was obtained from culture of nodal or apical segments on medium containing half-strength Murashige and Skoog salts without growth regulators. After 35 d of culture, an average of five buds developed per explant. Elongation and rooting of shoots also occurred in this medium. After the transfer of rooted plants to ex vitro conditions, 100% of the plantlets survived. Histochemical analysis of leaf tissue showed the presence of lipids, acidic lipids, essential oil, phenols, and flavonoids. The essential oils from conventionally propagated and acclimatized plants were extracted by hydrodistillation and analyzed using gas chromatography. The essential oil from acclimatized plants had a similar profile to that from ex vitro plants, but with a higher concentration of the anti-inflammatory compound alpha-humulene.     

In vitro anti-inflammatory and wound healing properties of Andrographis echioides and Andrographis paniculata

Andrographis echioides (L.) is an annual herbaceous plant in the family Acanthaceae. Anti-inflammatory is the property of a substance or treatment that reduces inflammation or swelling. Antioxidants are substances that can prevent or slow damage to cells caused by free radicals, unstable molecules that the body produces as a reaction to environmental and other pressures. They are sometimes called "free-radical scavengers. Therefore, it is of interest to analyse the anti-inflammatory and antioxidant properties of Andrographis echioides and Andrographis paniculata. Protease inhibitor activity was done by bovine serum albumin was added to 100µl of plant sample with increase in concentrations (100-500µg/ml). Invitro antioxidant activity was done by DPPH free radical scavenging assay. 200 µL of 0.1 mM DPPH prepared in methanol was added to 100 µL of the plant extract with increase in concentration. Based on the results from the present study, it can be concluded that A.echioides is found to be a good natural antioxidant source and A. paniculata is found to be a good anti-inflammatory source. However, both the plant A.echioides and A.paniculata have these properties. Data shows that both A.echioides and A. paniculata have potential anti-inflammatory and antioxidant activity which could be due to the presence of bioactive compounds present in the plant extracts.     

Genetic relationships between some Tunisian Citrus species based on their leaf volatile oil constituents

Volatile oil constituents of Tunisian sweet orange (Citrus sinensis Osbeck) cv. Meski (MES), Valencia Late (VAL), Thomson Navel (THN) and Maltaise Blanc (MAB); mandarin (Citrus reticulata Blanco); sour orange (Citrus aurantium L. cv. Amara (AM)) and pummelo (Citrus grandis Osbeck) were obtained by hydrodistillation and analysed by gas chromatography (GC) combined with a flame ionisation detector (FID) and mass spectrometry (MS). A total of 41 components accounting for more than 95% of the total essential oils were identified, and oxygenated monoterpenes (69.5–99.9%) were found as the most prominent fraction in all oil samples. The main constituents were linalool (3.1–73%), isoborneol (0–55.8%) and tepinen-4-ol (1.1–19.2%). A high degree of inter-and intraspecific chemical variability between species and cultivars was found to be genetically determined, and a set of distinctive traits (chemical markers) in the essential oils profile was established. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) of all identified components grouped the oils into two main chemotypes (linalool/isoborneol and isoborneol/linalool).     

Suppression of Powdery Mildew on Flax by Foliar Application of Essential Oils

Six essential oils were evaluated as to their efficiency in controlling powdery mildew (PM) of flax when they were applied as foliar sprays in an outdoor pot experiment. Onion, flax and fenugreek oils did not affect PM severity ratings – that is, they were ineffective in controlling the disease. On the other hand, black cumin, jojoba and coriander oil showed variable levels of efficiency in controlling the disease. Black cumin was moderately effective in controlling the disease because it reduced disease severity by 32.87%, while jojoba and coriander oils were highly effective as they reduced disease severity by 66.24 and 68.64%, respectively. Essential oils did not affect seed weight; however, coriander oil was a notable exception as it reduced seed weight by 55%. Straw weight was not affected by any oil. Foliar application of essential oils resulted in significant changes in the levels of protein, phenols, ascorbic acid and malondialdehyde and in activities of peroxidase and polyphenol oxidase. The lack of significant correlation between levels and activities of these biochemical components and PM severity demonstrate that these components are not involved in the suppression of PM by essential oils. Therefore, direct toxicity of essential oils to the causal pathogen Oidium lini is the most likely explanation for the disease suppression.     

Production of environmentally safe biocides from essential oils having antimicrobial activity

Different liquid formulations of anise, coriander and black cumin essential oils were used for preparing some biocides. The prepared formulations were tested for their antimicrobial activity against some post-harvest pathogenic microorganisms. The tested microorganisms were Fusarium oxysporum (Dray rot of potato), Alternaria alternata (Black rot of tomato), Penicillium italicum, P. digitatum, (Blue and green rot of orange, respectively), Botryitus cinerea (Gray rot of strawberry) and Erwinia carotovora (Soft rot of potato).The results revealed that the different formulations showed a complete inhibition effect on the growth of most of the tested microorganisms. Also, the antimicrobial activity of the formulated essential oils did not affect the formulation process compared with the original oil.     

Design,synthesis and pharmacological evaluation of omeprazole-like agents with anti-inflammatory activity

A new series of novel benzimidazole derivatives containing substituted pyrid-2-yl moiety and polyhydroxy sugar conjugated to the N-benzimidazole moiety has been synthesized and evaluated as orally bioavailable anti-inflammatory agents with anti-ulcerogenic activity. The anti-inflammatory and anti-ulcerogenic activities of these compounds were compared to diclofenac and omeprazole, respectively. In carrageenan-induced paw oedema assay, 2-methyl-N-((3,4-dimethoxypyridin-2-yl)methyl)-1H-benzimidazol-5-amine (12d) and 1-(1,2,3,5-tetrahydroxy-α-d-mannofuranose)-5-(((3,4-dimethoxypyridin-2yl)methyl)amino)-2-methyl-1H-benzimidazole (15d) displayed dose-dependent anti-inflammatory activities by decreasing the inflammation by 62% and 72%, respectively which is comparable to that of diclofenac (73%). In contrast to diclofenac, the anti-inflammatory activity of these compounds was not only free from any side effects on the gastric mucosa but also showed significant anti-ulcerogenic activity in rat pyloric ligation and ethanol-induced gastric ulcer models similar to that of omeprazole. Together, these findings suggest that 12d and 15d are potent anti-inflammatory agents with concurrent anti-ulcerogenic activity and support its clinical promise as a component of therapeutic strategies for inflammation, for which the gastric side effects are always a major limitation.     

Non-Oxygenated Sesquiterpenes in the Essential Oil of Copaifera langsdorffii Desf. Increase during the Day in the Dry Season

The present study aimed to evaluate the effect of seasonal and diurnal events on the chemical profile of the essential oil obtained from the leaves of Copaifera langsdorffii Desf. This study was performed in a Brazilian savanna named Cerrado. We identified the best harvesting period for obtaining the highest amount of compounds used for commercial and industrial purposes. The chemical profile of the essential oils was evaluated by GC-FID and GC-MS, and the results were assessed through multivariate analyses. The data showed that the time of day and seasonal variations affect the quality of the essential oil obtained. Leaves harvested at the end of the day (5:00 pm) in the dry season resulted in richer essential oils with higher amounts of non-oxygenated sesquiterpenes. To the best of our knowledge, environmental conditions induce metabolic responses in the leaves of C. langsdorffii, which changes the patterns of sesquiterpene production. Therefore, these factors need to be considered to obtain better concentrations of bioactive compounds for pharmacological studies.     

Chemical composition,antibacterial and antifungal activities of flowerhead and root essential oils of Santolina chamaecyparissus L., growing wild in Tunisia

The antimicrobial properties of essential oil from various Santolina species have not been investigated enough in the previous studies dealing with the biological activities of medicinal plants. In Tunisia, Santolina chamaecyparissus L. (Asteraceae) is the only Santolina species recorded and is used as vermifuge and emmenagogue. The chemical composition, antibacterial and antifungal properties of essential oils from the flowerheads and roots of spontaneous S. chamaecyparissus growing in Tunisia and the chemical composition which leads to the Tunisian chemotype are investigated here for the first time. Essential oils isolated by hydro distillation from flowerheads and roots of S. chamaecyparissus were analyzed by GC and GC/MS. Two methods served for antimicrobial assays of the essential oils: diffusion in a solid medium and micro-well dilution assay. Antifungal tests were carried out by the agar incorporation method. Sixty-seven constituents were identified from the essential oil of the flowerhead. The major constituents were: 1,8-cineole and β-eudesmol. Two non identified compounds were present at the highest concentration in root oil. Flowerhead oil was characterized by high contents in monoterpenes and sesquiterpenes oxygenated compounds. The flowerhead essential oil demonstrated potent of antibacterial properties against Pseudomonas aeruginosa ATCC and Enterococcus faecalis ATCC, with MIC of 0.625 μg/ml. These findings demonstrate that the flowerhead essential oils of S. chamaecyparissus have excellent antibacterial properties and for this reason they could contribute to decrease the problem of microbial resistance to antibiotics.