Anti-inflammatory activity of essential oils from Syzygium cumini and Psidium guajava

Abstract

Context: Despite the many biological activities reported for essential oils, their anti-inflammatory ability is relatively underexplored considering the wide variation in plant sources and in their volatile composition. Oils from Syzygium cumini Skells (SC) and Psidium guajava L. (PG) (Myrtaceae) have been described as having diverse pharmacological activities.

Objective: The current study seeks to evaluate the anti-inflammatory activity of the essential oils from the leaves of SC and PG, as well as some of their terpene-enriched fractions (+V?=?more volatile and ?V?=?less volatile) obtained by vacuum distillation. Both the pharmacological responses and chemical compositions were correlated.

Materials and methods: The relative contents of the oils and their fractions were evaluated by gas chromatography. Individual constituents in the oils were characterized by gas chromatography coupled to mass spectrometry. Anti-inflammatory activity was accessed in the lipopolysaccharide-induced pleurisy model, by measuring the inhibition of total leukocyte, neutrophil and eosinophil migration in the mice pleural lavage, after oil treatment with the oils at 100?mg/kg.

Results: Eosinophil migration was inhibited by SC (67%), SC (+V) (63%), PG (76%), PG (+V) (67%) and PG (?V) (74%). This efficacy was correlated with the presence of β-pinene and β-caryophyllene in the oils, a result that was reinforced by evaluating both these pure components (38 and 50% inhibition, respectively). Synergistic effects associated with the presence of α-pinene were speculated.

Discussion and conclusion: Essential oils from SC and PG may be useful to treat inflammatory diseases by mechanisms that include the inhibition of eosinophil migration.     

Development of essential oils as skin permeation enhancers: penetration enhancement effect and mechanism of action

Context: Essential oils (EOs) have shown the potential to reversibly overcome the stratum corneum (SC) barrier to enhance the skin permeation of drugs.

Objective: The effectiveness of turpentine, Angelica, chuanxiong, Cyperus, cinnamon, and clove oils were investigated for the capacity and mechanism to promote skin penetration of ibuprofen.

Materials and methods: Skin permeation studies of ibuprofen across rat abdominal skin with the presence of 3% w/v EOs were carried out; samples were withdrawn from the receptor compartment at 8, 10, 22, 24, 26, 28, 32, 36, and 48?h and analyzed for ibuprofen content by the HPLC method. The mechanisms of penetration enhancement of EOs were further evaluated by attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) analysis and determination of the properties of EOs. Moreover, the toxicities of EOs on skin cells were also measured.

Results: The enhancement ratio (ER) values of turpentine, Angelica, chuanxiong, Cyperus, cinnamon, clove oils and azone were determined to be 2.23, 1.83, 2.60, 2.49, 2.63 and 1.97, respectively. Revealed by ATR-FTIR analysis, a linear relationship (r?=?0.9045) was found between the ER values and the total of the shift of peak position of SC lipids. Furthermore, the results of HaCaT skin cell toxicity evaluation revealed that the natural EOs possessed relatively lower skin irritation potential.

Conclusion: Compared with azone, the investigated EOs possess significantly higher penetration enhancement effect and lower skin toxicity. EOs can promote the skin permeation of ibuprofen mainly by disturbing rather than extracting the SC lipids.     

Chemical Composition of Essential Oils from Leaves and Twigs of Pistacia lentiscus,Pistacia lentiscus var. chia,and Pistacia terebinthus from Turkey

The composition of the essential oils from the leaves and twigs of Pistacia lentiscus L., Pistacia lentiscus var. chia (L.), and Pistacia terebinthus L. of Turkish origin were analyzed by gas chromatography/mass spectrometry (GC/MS). Seventy-seven constituents were characterized from the essential oil of P. terebinthus leaves with α-cadinol (6.9%), phytol (5.4%), δ-cadinene (5.1%), α-terpineol (5.0%), and bornyl acetate (4.4%) as major constituents. Germacrene D (10%), β-pinene (7.5%), bornyl acetate (6.0%), α-cubebene (5.9%), and cubebol (5.4%) were found to be the main components among the 61 compounds characterized in the essential oil of P. terebinthus twigs. Forty-six compounds were characterized from the essential oil of P. lentiscus twigs with sabinene (23.2%), α-pinene (19.4%), germacrene D (14.1%), limonene (6.9%), β-phellandrene (6.5%), terpinene-4-ol (5.7%), and β-caryophyllene (5.7%) as the main constituents. Terpinene-4-ol (29.2%), β-caryophyllene (29.2%), and p-cymene (7.1%) were identified as the major components among the 64 compounds characterized in the essential oil of P. lentiscus leaves. Sixty-eight compounds were found on the essential oil of P. lentiscus var. chia leaves with germacrene D (20.1%), myrcene (13.9%), β-caryophyllene (10.8%), and α-terpinyl acetate (4.8%) as the major constituents. Myrcene (27.4%), germacrene D (21.7%), and β-caryophyllene (7.2%) were found to be the main components among 50 compounds characterized in the essential oil of P. lentiscus var. chia twigs.     

Anti-inflammatory and gastroprotective potential of leaf essential oil of Cinnamomum glanduliferum in ethanol-induced rat experimental gastritis

Context: Nothing could be found in the literature concerning Cinnamomum glanduliferum (Wall) Meissn (Lauraceae) bark (CG) in Egypt.

Objective: To investigate CG volatile oil chemically and its anti-inflammatory and gastroprotective effects.

Materials and methods: Essential oils were investigated by GC-MS. Leaves oil was assessed at doses of 250, 500 and 1000?mg/kg for its anti-inflammatory effect against carrageenan-induced rat oedema model. Serum inflammation markers were measured. The gastro-protective effect of the same doses of the volatile oil was also tested in ethanol-induced non-ulcerative gastritis model in rats. Stomach oxidative stress markers were examined following 1?h after intragastric ethanol administration.

Results: Twenty-five and 20 compounds were identified from leaf and branch oils, respectively (98.85 and 99.13%). The major ones were: eucalyptol (59.44%; 55.74%), sabinene (14.99%; 7.12%), α-terpineol (6.44%; 9.81%), α-pinene (5.27%; 4.71%). Following 4?h of treatment leaves volatile oil at doses of 250, 500 and 1000?mg/kg significantly reduced paw volume to 94, 82 and 69%, respectively. The same doses significantly reduced COX-2 activity to 73.8, 50.7 and 21.4?nmol/min/mL, respectively. A significant reduction of PGE2 concentration was observed (2.95?±?0.2, 2.45?±?0.15 and 1.75?±?0.015?pg/mL). CG oil exhibited a significant modulatory effect on ethanol-induced gastritis in rats as the level of NO reduced to 32, 37 and 41?μM nitrate/g and also a significant inhibition of lipid peroxidation was observed via reduction of MDA concentration (1.15, 1.11 and 1.04?nmol/g).

Conclusion: CG volatile oil exhibited an anti-inflammatory effect and protected against ethanol-induced non-ulcerative gastritis.     

Inhibition of methicillin-resistant Staphylococcus aureus (MRSA) by antimicrobial peptides (AMPs) and plant essential oils

Context: Drug-resistant bacterial infections cause considerable patient mortality and morbidity. The annual frequency of deaths from methicillin-resistant Staphylococcus aureus (MRSA) has surpassed those caused by human immunodeficiency virus/acquired immune deficiency syndrome. The antimicrobial peptides (AMPs), plant essential oils (EOs) and their combinations have proven to be quite effective in killing a wide selection of bacterial pathogens including MRSA.

Objectives: This review summarizes the studies in the use of AMPs, plant EOs and their combinations for coping with MRSA bacteria, and to formulate new prospects for future studies on this topic.

Methods: The sources of scientific literature such as PubMed, library search, Google Scholar, Science Direct and electronic databases such as ‘The Antimicrobial Peptide Database’, ‘Collection of Anti-Microbial Peptides’ and ‘YADAMP’. Physicochemical data of anti-MRSA peptides were determined by Scientific DataBase Maker software.

Results: Of the 118 peptides, 88 exhibited an activity against MRSA with the highest activity of minimum inhibitory concentration values. Various plant EOs have been effective against MRSA. Remarkably, lemongrass EOs completely inhibited all MRSA growth on the plate. Lemon myrtle, Mountain savory, Cinnamon bark and Melissa EOs showed a significant inhibition.

Conclusion: Several of these AMPs, EOs and their combinations were effective against MRSA. Their activities have implications for the development of new drugs for medical use.     

Differential effects of the essential oils of Lavandula luisieri and Eryngium duriaei subsp. juresianum in cell models of two chronic inflammatory diseases

Abstract

Context: Effective drugs to treat osteoarthritis (OA) and inflammatory bowel disease (IBD) are needed.

Objective: To identify essential oils (EOs) with anti-inflammatory activity in cell models of OA and IBD.

Materials and methods: EOs from Eryngium duriaei subsp. juresianum (M. Laínz) M. Laínz (Apiaceae), Laserpitium eliasii subsp. thalictrifolium Sennen & Pau (Apiaceae), Lavandula luisieri (Rozeira) Rivas-Martínez (Lamiaceae), Othantus maritimus (L.) Hoff. & Link (Asteraceae), and Thapsia villosa L. (Apiaceae) were analyzed by GC and GC/MS. The anti-inflammatory activity of EOs (5–200?μg/mL) was evaluated by measuring inducible nitric oxide synthase (iNOS) and nuclear factor-κB (NF-κB) activation (total and phosphorylated IκB-α), in primary human chondrocytes and the intestinal cell line, C2BBe1, stimulated with interleukin-1β (IL-1β) or interferon-γ (IFN-γ), IL-1β and tumor necrosis factor-α (TNF-α), respectively.

Results: The EO of L. luisieri significantly reduced iNOS (by 54.9 and 81.0%, respectively) and phosphorylated IκB-α (by 87.4% and 62.3%, respectively) in both cell models. The EO of E. duriaei subsp. juresianum caused similar effects in human chondrocytes, but was inactive in intestinal cells, even at higher concentrations. The EOs of L. eliasii subsp. thalictrifolium and O. maritimus decreased iNOS expression by 45.2?±?8.7% and 45.2?±?6.2%, respectively, in C2BBe1 cells and were inactive in chondrocytes. The EO of T. villosa was inactive in both cell types.

Discussion and conclusion: This is the first study showing anti-inflammatory effects of the EOs of L. luisieri and E. duriaei subsp. juresianum. These effects are specific of the cell type and may be valuable to develop new therapies or as sources of active compounds with improved efficacy and selectivity towards OA and IBD.     

Evaluation of different Mediterranean essential oils as prophylactic agents in anisakidosis

Context: Anisakis Dujardin 1845 (Anisakidae) nematodes can cause gastrointestinal and allergic diseases when humans eat raw or undercooked seafood containing larvae. There is currently no drug available in the market against this parasitic disease, and the study of plant-derived molecules could be useful in the discovery of effective compounds.

Objective: This research assesses the biocidal activity of a range of essential oils (EOs) from some Mediterranean plants against larvae found in the musculature of fresh fish.

Materials and methods: EOs composition was analyzed by gas chromatography-mass spectroscopy. All the EOs were diluted at 5% v/v in olive oil to cover the fish with the solutions for 24?h. The larvae that abandoned the muscle and the larvae obtained from the artificial digestion of the fish were collected. Controls were carried out in parallel. Furthermore, Wistar rats were infected with the live larvae collected from the in vitro trials in order to find any larvae that may have penetrated the gastrointestinal wall.

Results: Between 60.8% and 87.6% of parasites treated with EOs abandoned the fish muscle, and the highest in vitro mortality rate was achieved with oregano EO (53.9%). Rats previously treated with oregano, cumin and Spanish lavender EOs showed no detectable lesions in the digestive tract due to the infection with larvae.

Conclusions: Oregano (Origanum vulgare L. Lamiaceae), cumin (Cuminum cyminum L. Apiaceae) and Spanish lavender (Lavender stoechas L. Lamiaceae) EOs could be used as promising ingredients in the development of products for the control of anisakiasis.     

GC-MS Analysis and Antimicrobial Activity of the Essential Oil from the Stem of the Jordanian Toothbrush Tree Salvadora persica.

Abstract

Chemical composition of the essential oil of the stem of the toothbrush tree Salvadora persica. L. grown in Jordan was determined by gas chromatography-mass spectrometry (GC-MS). The oil obtained by hydrodistillation (yield: 0.6% w/w) was determined as a mixture of monoterpene hydrocarbons (11%), oxygenated monoterpenes (54%), and sesquiterpene hydrocarbons (21%). The major components identified were 1,8-cineole (eucalyptol) (46%), α-caryophellene (13.4%), β-pinene (6.3%), and 9-epi.-(E.)-caryophellene. The antimicrobial activity of the volatile oils and aqueous and alcohol extracts of the plant has been also evaluated. Among all tested fractions, the volatile oils exhibited potent activity against both sensitive and resistant strains of Pseudomonas aeruginosa. (Schroeter and Migula) and Staphylococcos aureus. (Rosenbach). Moreover, the oil revealed significant inhibition against Candida albicans. (C. P. Robin) and Trichosporon cutaneum. (Beurm, Govgerot and Vaucher).     

Effects of Salvia. Essential Oils on the Chorioallantoic Membrane (CAM) Assay

Abstract

The aerial parts of Salvia hedgeana. Dönmez, Salvia huberi. Hedge, Salvia pisidica. Boiss. & Heldr. ex. Bentham. were subjected to hydrodistillation. The obtained essential oils were analyzed both by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The analyses showed that S. hedgeana. essential oil consisted of β-pinene (30.0%) as a major component, in addition to 65 identified components, representing 89.9% of the total essential oil. The major component of S. huberi. was identified as 1,8-cineole (20.4%), and 76 further components were characterized representing 87.6%. S. pisidica. essential oil revealed the occurrence of camphor (21.7%) as the main constituent among another 59 identified components of 76.8% of the total. Furthermore, the biological properties of the analyzed essential oils were tested using the in vivo. method on the chorioallantoic membrane (CAM) in order to examine the anti-inflammatory and anti-angiogenic activity as well as possible irritant or toxic side effects. All essential oils tested at a concentration of 100 µg/pellet showed no pronounced anti-inflammatory, angiogenic, or membrane-toxic properties.     

Chemical composition,antioxidant and antibacterial activities of essential oils from Ferulago angulata

Context: Ferulago angulata Boiss. (Apiaceae), a perennial aromatic herb, grows wild in Iran. The aerial parts of F. angulata are used as a flavouring in foods, especially dairy foods by indigenous people in western and southwestern Iran.

Objective: This study investigates variation in chemical compositions, antioxidant and antibacterial activities of the essential oils from F. angulata collected from natural habitats in the alpine regions of southwestern Iran.

Materials and Methods: The antimicrobial activity, minimum inhibitory concentration (MIC) and minimum bactericidal (MBC) of the essential oils were evaluated against four bacteria (Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus and Salmonella typhimurium). Antioxidant activity of the oils was determined by DPPH assay.

Results: The essential oils were analyzed by GC-FID and GC/MS, which 49 volatile components were identified. There were significant differences between the various populations for oil yield and some main compounds. The major constituents of the essential oils from F. angulata were α-pinene, and cis-β-ocimene. The MICs of the essential oils were within concentration ranges from 62 to 250?μg/mL and the respective MBCs were 125 to?>?500?μg/mL. Generally, the oils from F. angulata indicated weak to moderate inhibitory activities against bacteria, especially against Listeria monocytogenes. The highest antioxidant activity was obtained from the oil of the Kallar population (IC₅₀ value_?=_?488?μg/mL) and BHT as positive control (IC_50? value =_?321?μg/mL).

Discussion and conclusion: The essential oil of F. angulata could be serving as a potential source of α-pinene and cis-β-ocimene for use in the food, cosmetic and pharmaceutical industries.     

武当玉兰花蕾及其枝条挥发油的化学成分分析和比较

用高效毛细管气相色谱法和气相色谱—质谱考察了武当玉兰花蕾及其枝条挥发油的化学成分,共检出40个组分,鉴定了其中的32个成分,并用峰面积归一法作了测定,其中含量在5%以上的有β-蒎烯、香桧烯、对-缴花烃、乙酸龙脑脂、反-丁香烯、丁香烯氧化物和β-桉油醇。比较结果表明,两者的化学成分有着明显的差别,花蕾挥发油所含倍半萜醇和倍半萜烃较枝条挥发油为多,而含单萜烃则较少。     

Chemical composition and bioactivity of essential oils of Hypericum helianthemoides. Hypericum perforatum and Hypericum scabrum

Context: A number Hypericum species are well known for their therapeutic efficacy and use in traditional medicine. The various species of Hypericum have been traditionally used for the treatment of wounds, eczema, burns, trauma, rheumatism, neuralgia, gastroenteritis, ulcers, hysteria, bedwetting and depression.

Objective: This study evaluated the in vitro antioxidant, antibacterial and phytochemical properties of essential oils of Hypericum helianthemoides (Spach) Boiss., Hypericum perforatum L. and Hypericum scabrum L. (Hypericaceae) collected from alpine region of Southwest Iran.

Materials and methods: The essential oils obtained from dried flowering aerial parts of three Hypericum species were analyzed by gas chromatography and gas chromatography/mass spectrometry to determine chemical compositions. The antibacterial activity of essential oils within concentration ranges from 16 to 500?µg/mL was individually evaluated against Bacillus cereus, Listeria monocytogenes. Proteus vulgaris and Salmonella typhimurium. The 1,1-diphenyl-2-picrilhydrazyl (DPPH) radical scavenging activity of essential oils was determined using DPPH assay.

Results: Essential oil yield of H. helianthemoides. H. scabrum and H. perforatum were 0.12, 0.20 and 0.21?mL/100?g dried material, respectively. The major constituents of the essential oils were α-pinene (12.52–49.96%), β-pinene (6.34–9.70%), (E)-β-ocimene (4.44–12.54%), β-caryophyllene (1.19–5.67%), and germacrene-D (2.34–6.92%). The essential oils of three Hypericum species indicated moderate-to-good inhibitory activities against four bacteria, especially against L. monocytogenes.

Discussion and conclusion: The essential oils of the three studied Hypericum species sourced in alpine region of West Iran were rich in monoterpene and sesquiterpenes hydrocarbons. Among the three tested species, the essential oil of H. scabrum showed the highest antibacterial and antioxidant activities.     

Essential oil from fruit of Xylopia langsdorffiana: antitumour activity and toxicity

Context: The genus Xylopia L. (Annonaceae) includes aromatic plants that have both nutritional and medicinal uses. Essential oils of Xylopia species have antitumour effects. However, the efficacy of the essential oil from the fruit of Xylopia langsdorffiana St. Hil & Tul. (EOX) has not been examined.

Objective: EOX was evaluated to determine its chemical composition, antitumour activity and toxicity.

Materials and methods: EOX was obtained from fresh fruits of X. langsdorffiana subjected to hydrodistillation, and gas chromatography-mass spectrometry was used to characterize the chemical composition of EOX. The toxicity of EOX was evaluated using haemolysis, acute toxicity and micronucleus assays. The in vitro antitumour activity of EOX was investigated using the sulforhodamine B assay. The sarcoma 180 murine tumour model was used to evaluate the in vivo antitumour activity and toxicity of EOX (50 and 100?mg/kg) after 7 d of treatment.

Results: The major components of EOX were α-pinene (34.57%) and limonene (31.75%). The HC₅₀ (concentration producing 50% haemolysis) was 293.6?μg/ml. EOX showed greater selectivity for the leukaemia cell line K562, with total growth inhibition (TGI) (concentration producing TGI) of 1.8?μg/ml, and for multidrug-resistant ovarian tumour cell line NCI/ADR-RES (TGI of 45.4?μg/ml). The LD₅₀ was approximately 351.09?mg/kg. At doses of 50 and 100?mg/kg, EOX inhibited the in vivo growth of sarcoma 180 by 38.67 and 54.32%, respectively. EOX displayed minor hepatic alterations characteristic of acute hepatitis and induced no genotoxicity.

Conclusion: EOX showed in vitro and in vivo antitumour activity and low toxicity, which warrants further pharmacological studies.     

Chemical composition,antimicrobial, and cytotoxicity studies on S. erianthum and S. macranthum essential oils

Context: Solanum erianthum D. Don and Solanum macranthum Dunal (Solanaceae) are widely used in traditional medicine. The leaves act as an abortifacient and in particular to treat leucorrhoea, sores, and skin irritations.

Objective: This study was undertaken to characterize the volatile constituents of the leaf and fruit essential oils of S. erianthum and S. macranthum; their antimicrobial and in vitro cytotoxic bioassay against human breast and prostate tumor cells.

Methods: The volatile oils were obtained by hydrodistillation and analyzed for their constituents by gas chromatography-mass spectrometry (GC-MS). Minimum Inhibitory Concentrations (MIC) were determined using the microbroth dilution technique while the cytotoxic potentials were evaluated using the Cell Titre 96^(R) AQ_ueous Non-Radioactive Cell Proliferation Assay method.

Results: Solanum erianthum essential oils were characterized by the abundance of α-terpinolene (17.8%), α-phellandrene (17.5%), p-cymene (15.7%) and β-pinene (11.7%) in the leaves; α-humulene (23.1%), humulene epoxide II (20.0%), caryophyllene oxide (16.5%), methyl salicylate (11.8%) and β-caryophyllene (10.9%) in the fruits. The leaf oil of S. macranthum consisted of (E)-phytol (29.0%), pentadecanal (28.1%) and pentadecane (7.7%) while the major fruit oil constituents were α-humulene (36.5%), β-caryophyllene (17.8%), ethyl palmitate (9.4%), and methyl salicylate (8.2%). Solanum erianthum leaf volatile oil demonstrated potent inhibitory activity against Hs 578T and PC-3 human breast and prostate tumor cells respectively. In addition, the Solanum essential oils exhibited significant antimicrobial activity (19.5–625 µg/mL) on pathogens employed in the assay.

Conclusion: The Solanum essential oils possess strong antimicrobial activity in addition to the potent cytotoxic potential of S. erianthum leaf oil against Hs 578T and PC-3 cells.     

Major selected monoterpenes α-pinene and 1,8-cineole found in Salvia lavandulifolia (Spanish sage) essential oil as regulators of cellular redox balance

Abstract

Context: Salvia lavandulifolia has been employed in folk medicine for the treatment of memory and dementia problems. This specie contains numerous bioactive terpenes which may contribute to its effectiveness.

Objective: To analyze the composition of essential oil of S. lavandulifolia and to investigate the potential in vitro cytoprotective and antioxidant activities of its major compounds, α-pinene and 1,8-cineole, against H₂O₂-induced oxidative stress in the U373-MG cell line.

Materials and methods: Chemical composition was analyzed by gas chromatography; antioxidant capacity was measured using the ORAC assay, and cytoprotective activity was evaluated using the MTT assay (for cell viability) (range of concentrations: 10–400?μM), DCFH-DA assay (for intracellular ROS generation), thiobarbituric acid reactive substances (TBARS) method (for lipid peroxidation), and spectrofometric techniques and Western blot (for enzymatic activity and protein expression, respectively) at 10 and 25?µM.

Results: α-Pinene (18.39%) and 1,8-cineole (19.57%) were identified as major compounds in S. lavandulifolia essential oil. Pretreatments with these monoterpenes protected U373-MG cells against H₂O₂-induced oxidative injury by attenuating the loss of cell viability (IC₅₀ : 79.70?µM to α-pinene and 66.23?µM to 1,8-cineole) and cell morphology, inhibiting ROS production (the most active compound was 1,8-cineole by decreasing the ROS production over 30–45% at 10 and 25?μM) and lipid peroxidation and increasing the endogenous antioxidant status (glutathione levels and CAT, SOD, GR, GPx, and HO-1 activity and protein expression).

Conclusions: These findings demonstrate for the first time the effects of the monoterpenes 1,8-cineole and α-pinene identified in S. lavandulifolia essential oil as regulators of cellular redox balance in astrocytes.     

Antimicrobial and antibiofilm activity of Baccharis psiadioides essential oil against antibiotic-resistant Enterococcus faecalis strains

Context: Baccharis psiadioides (Less.) Joch. Müller (Asteraceae) is considered as a producer of bioactive essential oils and is used in south Brazilian folk medicine for its proprieties as stimulant, antipyretic, anti-inflammatory and as an antidote for snake bites.

Objective: To verify the antimicrobial and antibiofilm activities of the essential oil of B. psiadioides (EOBP) against antibiotic-resistant Enterococcus faecalis.

Materials and methods: The initial evaluation of EOBP activity was conducted by the agar and microdilution methods against 13 antibiotic-resistant E. faecalis strains. The antibiofilm effect was determined by the application of EOBP in the earlier adherent cells or to the stabilized biofilm for 24?h and was evaluated by crystal violet, viability and scanning electron microscopy (SEM) assays. Chemical composition of EOBP was determined by gas chromatography (GC/FID – GC/MS).

Results: The MIC values for EOBP were at least 1.25% and 4–16% for agar and microdilution assays, respectively. The EOBP reduced the microbial adherence and the viability of the cells, but did not cause the complete disruption of biofilms. SEM images indicate that EOBP influences the adherence of cells to a surface. The monoterpene β-pinene was the major constituent identified in EOBP.

Conclusion: This research shows the ability of EOBP to control resistant E. faecalis strains and to reduce the biofilm amount attached to abiotic surfaces, indicating its role as a promising new natural antimicrobial agent. Moreover, these results further contribute to the growing number of studies of plant natural products which suggest that these compounds can combat resistant microorganisms.     

Biochemical characterization,anti-inflammatory properties and ulcerogenic traits of some cold-pressed oils in experimental animals

Context: Cold-pressed oils (CPO) are commercially available in the market and characterized by their health-promoting properties.

Objective: Clove oil (CLO), coriander seed oil (COO) and black cumin oil (BCO) were evaluated for their bioactive lipids. Pharmacological screening was performed to evaluate acute toxicity, anti-inflammatory and ulcerogenic effects as well as histopathological changes in tissues of albino rats fed with CPO.

Materials and methods: Fatty acids, tocols and total phenolics were analyzed. The acute toxicity test for each CPO was estimated during 14 d. Carrageenan-induced rat paw oedema was used for assessment of anti-inflammatory activity of CPO. Animals were fasted overnight, and via oral gavage given indomethacin (10?mg/kg) or CPO (400?mg/kg) to investigate ulcerogenecity. Histopathological changes in liver, kidney, heart, spleen and stomach were screened.

Results: Amounts of α-, β-, γ- and δ-tocopherols in CLO were 1495, 58, 4177 and 177?mg/kg oil, respectively. In COO, α, β, γ and δ-tocopherols were 10.0, 18.2, 5.1 and 34.8%, respectively. In BCO, β-tocotrienol was the main constituent. CLO, COO and BCO contained 4.6, 4.2 and 3.6?mg GAE/g, respectively. Acute toxicity test determined that 400?mg/kg of CPO to be used. In the carrageenan model of inflammation, pretreatment of rats with indomethacin (10?mg/kg) or CLO (400?mg/kg) induced a significant (p?Conclusions: CPO, particularly CLO, could minimize acute inflammation.     

Essential oils from Schinus terebinthifolius leaves – chemical composition and in vitro cytotoxicity evaluation

Context: In folk medicine, Schinus terebinthifolius Raddi (Anacardiaceae), has been used as a remedy for ulcers, respiratory problems, wounds, rheumatism, gout, diarrhea, skin ailments and arthritis, as well as to treat tumors and leprosy.

Objective: To investigate the chemical composition and cytotoxicity of essential oil from leaves of S. terebinthifolius as well as the identification of active compounds from this oil.

Material and methods: Essential oil from S. terebinthifolius leaves, obtained by hydrodistillation using a Clevenger-type apparatus, was characterized in terms of its chemical composition. Also, the crude oil was subjected to chromatographic separation procedures to afford an active fraction composed of α- and β-pinenes. These compounds, including hydrogenation (pinane) and epoxydation (α-pinene oxide) derivatives from α-pinene, were tested in vitro against murine melanoma cell line (B16F10-Nex2) and human melanoma (A2058), breast adenocarcinoma (MCF7), leukemia (human leukemia (HL-60) and cervical carcinoma (HeLa) cell lines.

Results: Forty-nine constituents were identified in the oil (97.9% of the total), with germacrene D (23.7%), bicyclogermacrene (15.0%), β-pinene (9.1%) and β-longipinene (8.1%) as the main compounds. The crude essential oil showed cytotoxic effects in several cell lines, mainly on leukemia and human cervical carcinoma. Fractions composed mainly of α- and β-pinenes as well as those composed of individually pinenes showed effective activities against all tested cell lines. Aiming to determinate preliminary structure/activity relationships, α-pinene was subjected to epoxydation and hydrogenation procedures whose obtained α-pinene oxide showed an expressive depression in its cytotoxicity effect, similar as observed to pinane derivative.

Discussion and conclusion: The obtained results indicated that the monoterpenes α- and β-pinenes could be responsible to the cytotoxic activity detected in the crude oil from leaves of S. terebinthifolius. In addition, it was possibly inferred that the presence of double bond in their structures, mainly at endocyclic position, is crucial to cytotoxic potential detected in these derivatives.     

Transdermal absorption enhancing effect of the essential oil of Rosmarinus officinalis on percutaneous absorption of Na diclofenac from topical gel

Abstract

Context: Rosemary essential oil has been used topically for several purposes (analgesic, anti acne, and anti-inflammatory) in Iranian traditional medicine.

Objectives: This investigation aimed to study the effect of essential oil of Rosmarinus officinalis L. (Lamiaceae) on the transdermal absorption of Na diclofenac from topical gel.

Material and methods: Diclofenac sodium topical gel was prepared with HPMC K4M and Carbopol 934P as a gelling agent, and several vehicles. The most stable gel was chosen and enhancing effects of the essential oil with different concentrations (0.1, 0.5, and 1.0% w/w) on the permeation of diclofenac were evaluated. The anti-nociceptive effect of preparations was evaluated based on the formalin and tail flick tests in mice.

Results: The major constituents of the essential oil were 1,8-cineol (15.96%), α-pinene (13.38%), camphor (7.87%), bornyl acetate (6.54%), verbenone (5.82%), borneol (5.23%), camphene (4.96%), and (E)-caryophyllene (3.8%). Topical diclofenac containing 0.5% essential oil showed more analgesic effect after 25, 30, and 35?min (p?<?0.001) than the reference drug in the tail flick test. The analgesic effect of preparation containing 1% essential oil was more than reference gel after 15?min (p?<?0.05). This difference was observed after 20, 25, 30, 35, and 40?min (p?<?0.001) too. Rosemary essential oil 1% promoted analgesic effect of drug in comparison with diclofenac gel in the formalin early phase (p?<?0.05). The enhancing effect of rosemary was observed in 0.5 and 1% concentration (p?<?0.05 and p?<?0.001, respectively) in the late phase.

Conclusion: This study proved the enhancing effect of 0.5 and 1% of rosemary essential oil on diclofenac percutaneous absorption.     

The monoamine oxidase inhibitory activity of essential oils obtained from Eryngium species and their chemical composition

Context Monoamine oxidase (MAO) inhibitors are used in the treatment of depression, anxiety disorders, and the symptomatic treatment of Parkinson's disease. Eryngium, the most representative of the Apiaceae family, is well known for the presence of essential oils (EOs), which have already demonstrated MAO inhibitory potential.

Objective The objective of this study is to evaluate the MAO inhibitory capacity of the EOs obtained from Eryngium floribundum Cham. & Schlecht. (EF), E. eriophorum Cham. & Schlecht. (EE), E. nudicaule Lam. (EN), E. horridum Malme (EH), and E. pandanifolium Cham. & Schlecht. (EP).

Materials and methods EOs were obtained from fresh whole plants by hydrodistillation (3?h). Chemical analyses were performed by GC/MS using apolar and polar columns, with oven temperature from 60 to 300?°C at 3?°C/min. The MAO-A and -B activities were evaluated in vitro by an end-point method using kynuramine as the substrate and mitochondrial suspension or human recombinant enzymes as the enzymatic source. DMSO 2%, clorgyline 10^?7 M, and pargyline 10^?6 M were used as controls.

Results and discussion EFEO, EEEO, ENEO, EHEO, and EPEO GC/MS analysis showed (E)-caryophyllene (4.9–10.8%), germacrene D (0.6–35.1%), bicyclogermacrene (10.4–17.2), spathulenol (0.4–36.0%), and globulol (1.4–18.6%) as main constituents. None of the EOs inhibited MAO-A activity (4 and 40?μg/mL). However, EHEO inhibited MAO-B activity with an IC₅₀ value of 5.65?μg/mL (1–200?μg/mL). Pentadecane (10?μM), its major constituent (53.5%), did not display significant MAO-B inhibition.

Conclusion The study demonstrates the promising application of Eryngium species as a source of potential central nervous system bioactive secondary metabolites, specially related to neurodegenerative disorders.