In vitro antibiofilm activity of Murraya koenigii essential oil extracted using supercritical fluid CO2 method against Pseudomonas aeruginosa PAO1

The antibiofilm activity of Murraya koenigii essential oil (EO) against Pseudomonas aeruginosa PAO1 was investigated in this study. A decrease in the production of rhamnolipid, extracellular polymeric substance and swarming motility was observed by the EO treatment (0.3% v/v). The static microtitre plate assay revealed 80% reduction in biofilm formation by P. aeruginosa PAO1 on M. koenigii EO treatment. Fluorescence microscopy and scanning electron microscopy analyses confirmed the reduction of biofilm formation in P. aeruginosa PAO1 when treated with M. koenigii EO. Gas chromatography–mass spectrometry analysis of the EO revealed the presence of well-known antibiofilm agents such as spathulenol (5.85%), cinnamaldehyde (0.37%) and linalool (0.04%). Cinnamaldehyde has not been previously reported in M. koenigii EO. The potent antibiofilm properties of M. koenigii EO may be effectively exploited in food and pharmaceutical industries as well as in controlling Pseudomonas biofilms on indwelling medical devices.     

In vitro interactions of Peucedanum officinale essential oil with antibiotics

The chemical composition and antibacterial activity of Peucedanum officinale L. (Apiaceae) essential oil were examined, as well as the association between it and antibiotics: tetracycline, streptomycin and chloramphenicol. The interactions of the essential oil with antibiotics were evaluated using the microdilution checkerboard assay. Monoterpene hydrocarbons, with α-phellandrene as the dominant constituent, were the most abundant compound class of the essential oil of P. officinale. The researched essential oil exhibited slight antibacterial activity against the tested bacterial strains in vitro. On the contrary, essential oil of P. officinale possesses a great synergistic potential with chloramphenicol and tetracycline. Their combinations reduced the minimum effective dose of the antibiotic and, consequently, minimised its adverse side effects. In addition, investigated interactions are especially successful against Gram-negative bacteria, the pharmacological treatment of which is very difficult nowadays.     

Chemical composition and antibacterial activity of Lavandula coronopifolia essential oil against antibiotic-resistant bacteria

The aim of this study was to analyse the composition of the essential oil (EO) of Lavandula coronopifolia from Morocco and to evaluate its in vitro antibacterial activity against antibiotic-resistant bacteria isolated from clinical infections. The antimicrobial activity was assessed by a broth micro-well dilution method using multiresistant clinical isolates of 11 pathogenic bacteria: Klebsiella pneumoniae subsp. pneumoniae, Klebsiella ornithinolytica, Escherichia coli, Enterobacter cloacae, Enterobacter aerogenes, Providencia rettgeri, Citrobacter freundii, Hafnia alvei, Salmonella spp., Acinetobacter baumannii and methicillin-resistant Staphylococcus aureus. The main compounds of the oil were carvacrol (48.9%), E-caryophyllene (10.8%) and caryophyllene oxide (7.7%). The oil showed activity against all tested strains with minimal inhibitory concentration (MIC) values ranging between 1% and 4%. For most of the strains, the MIC value was equivalent to the minimal bactericidal concentration value, indicating a clear bactericidal effect of L. coronopifolia EO.     

Evaluation of the anti-Leishmania major activity of Satureja bakhtiarica essential oil in vitro

Leishmaniasis is a painless chronic skin disease that is caused by the protozoan parasite Leishmania. Due to the importance of this disease and the side effects of chemical drugs, use of drugs of plant origin to treat Leishmaniasis is very important. In the present study, the chemical composition and the anti-Leishmania major activity of the essential oils obtained from Satureja bakhtiarica were evaluated in vitro. The oils were extracted using a Clevenger apparatus and then the chemical composition was analyzed by GC-MS. Promastigotes of L. major were cultured in both N.N.N and RPMI1640 media. GC-MS analysis showed 13 compounds, in which the major components were the phenolic (37.4%) compounds, thymol (22.6%) and p-cymene (19.3%). The essential oil of S. bakhtiarica showed higher activity against L. major than the standard anti-Leishmania drug, glucantime,. Perhaps because of the high concentration of phenolic compounds in the essential oil, all the parasites were killed after 24 hours. The essential oil from S. bakhtiarica is a potential plant drug against leishmaniasis. Further studies are necessary to evaluate this oil in animal models (in vivo) for future drug applications.     

In vitro antimicrobial properties and chemical composition of Santolina chamaecyparissus essential oil from Algeria

The chemical composition of the essential oil obtained from the aerial parts of Santolina chamaecyparissus L., growing in Algeria, was investigated by GC-MS analyses. A total of 36 compounds were identified, accounting for 91.7% of the essential oil obtained. Camphor (31.1%) and cubenol (17.0%) were the predominant compounds. The potential of the antimicrobial activity was also investigated and the tested sample proved to be very active against Klebsiella pneumonia and Candida albicans (34.1 +/- 0.02 mm and 35.0 +/- 0.01 mm, respectively). Transverse sections of the leaf and stem of the plant suggest that the essential oil is localized in endogenous and exogenous sites.     

In vitro anti-inflammatory and xanthine oxidase inhibitory activity of Tephrosia purpurea shoot extract

The methanolic extract of Tephrosia purpurea (Leguminosae) shoots was evaluated in-vitro for its anti-inflammatory and xanthine oxidase inhibitory activity. Anti-inflammatory activity was measured by the Diene-conjugate, HET-CAM and beta-glucuronidase methods. The enzyme inhibitory activity was tested against isolated cow milk xanthine oxidase. The average anti-inflammatory activity of T. purpurea shoot extract in the concentration range of 1-2 microg/mL in the reacting system revealed significant anti-inflammatory activities, which, as recorded by the Diene-conjugate, HET-CAM and beta-glucuronidase assay methods, were 45.4, 10.5, and 70.5%, respectively. Screening of the xanthine oxidase inhibitory activity of the extract in terms of kinetic parameters revealed a mixed type of inhibition, wherein the Km and Vmax values in the presence of 25 to 100 microg/mL shoot extract was 0.20 mM/mL and 0.035, 0.026, 0.023 and 0.020 microg/min, while, for the positive control, the Km and Vmax values were 0.21 mM/mL and 0.043 microg/min, respectively. These findings suggest that T. purpurea shoot extract may possess constituents with good medicinal properties that could be exploited to treat the diseases associated with oxidative stress, xanthine oxidase enzyme activity and inflammation.     

Antifungal activity of essential oil from Asteriscus graveolens against postharvest phytopathogenic fungi in apples

The essential oils of the aerial parts of Asteriscus graveolens have been studied using GC and GC-MS. Twenty-eight compounds were identified in the essential oil amounting to 94.9% of the total oil. The aerial part oils showed similar chromatographic profiles and were characterized by having a high content of oxygenated sesquiterpenes with 6-oxocyclonerolidol (66.7% +/- 5.5) and 6-hydroxycyclonerolidol (8.8% +/-1.2) as the major components. The antifungal effect of the essential oil from A. graveolens leaves was evaluated in vitro against three phytopathogenic fungi of apples (Alternaria sp., Penicillium expansum, and Rhizopus stolonifer). The results suggest that this essential oil has fungicidal properties towards Alternaria sp. from direct contact assay at 0.2% (v/v) and to P. expansum from vapor assay tests at 80 microL.     

Chemical composition and antimicrobial activity of Satureja kitaibelii essential oil against pathogenic microbial strains

Plant species Satureja kitaibelii Wierzb. ex Heuff. is used as a spice and as a natural preservative for food and herbal tea, owing to its characteristic scent and flavor as well as high antimicrobial activity. In the present study, the antimicrobial activity of isolated essential oil of S. kitaibelii was tested against a panel of 30 pathogenic microorganisms (foodborne microbes, selected multiresistant bacterial isolates from the patient wounds and dermatophyte isolates). Limonene (15.54%), p-cymene (9.99%), and borneol (8.91%) appeared as the main components in 44 identified compounds representing 98.44% of the oil. Essential oil of S. kitaibelii showed significant activity against a wide spectrum of foodborne microbes (MIC=0.18-25.5 microg mL(-1)) and multiresistant bacterial isolates (MIC=6.25-50.0 microg mL(-1)), as well as against dermatophyte strains (MIC=12.5-50.0 microg mL(-1)). These results demonstrate that S. kitaibelii essential oil could be used as a natural potential antimicrobial agent against pathogenic strains in the treatment of foodborne disease, wound and skin infections.     

“In vitro” activity of Melaleuca cajuputi against mycobacterial species

Abstract

The increasing incidence of resistance in tuberculosis and in atypical mycobacterial infections has prompted the search for alternative agents. We explored the antimycobacterial activity of Melaleuca cajuputi essential oil against tubercular and non tubercular mycobacterials isolates. The good activity observed towards M. cajuputi indicated that this essential oil might represent a promising antimicrobial agents, particularly in the management of microbial resistance.     

Nanoemulsion of Myrtus communis essential oil and evaluation of its larvicidal activity against Anopheles stephensi

PurposeExcessive use of chemical insecticides has caused environmental pollution and vector resistance. Herbal essential oils with larvicidal properties are good alternatives to synthetic insecticides.mIn this study, larvicide properties of Myrtus communis essential oil and its nanoemulsion against Anopheles stephensi were investigated.MethodsComponents of Myrtus communis essential oil were identified by GC–MS. Nanoemulsion of essential oil was made with Tween 80, Span 20, and water. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) determined particle size and morphology of nanoemulsions. The larvicide activity compared with bulk essential oil.ResultsA total of 107 M. communis essential oil compounds were discovered. The morphology of a selected nanoemulsion was spherical. LC₅₀ and LC₉₀ of M. communis essential oil were calculated as 26.1 and 46.2 µg/ml, respectively. The larvicide activity of nanoemulsion increased by 40% compared to the bulk essential oil. The nanoemulsion's larvicide activity (100%) lasted up to 3 days, while the essential oil had larvicide properties only for up to 24 h.ConclusionsMyrtus communis essential oil was found to be an effective larvicide and classified as an active larvicide. The residual efficacy of the nanoformulation of M. communis significantly increased compared with the bulk essential oil.     

Oviposition-stimulatory activity against Ostrinia zealis by essential oil of root part from Cirsium japonicum DC

The essential oil components from root part of Cirsium japonicum and oviposition-stimulatory activity against Ostrinia zealis by root essential oil were investigated. The main component of fresh root essential oil was aplotaxene (75.14%) and of dried root stock was found to be palmitic acid (14.42%). The root oil was significantly more active than the control against O. zealis.     

In vitro anti-tumor activity of the tanshinone IIA against SKOV3 cells

The aim of this study was to determine the anti-tumour activity of tanshinone IIA in SKOV3 cells. Results suggested that tanshinone IIA could significantly inhibit (IC₅₀ value = 19.6 μM) the proliferation and induce apoptosis of SKOV3 cells as demonstrated by flow cytometry analysis. In addition, tanshinone IIA treatment induced G2/M phase cell cycle arrest in SKOV3 cells. The results of Western blotting indicated that tanshinone IIA can suppress the expression of anti-apoptotic protein Bcl-2, increase (0.28 vs. 0.62) the expression of pro-apoptotic protein Bax (0.83 vs. 0.24) in SKOV3 cells. It can be concluded that the tanshinone IIA may be a possible therapeutic candidate having cytotoxic and anti-tumour potential.     

In vitro activity of compounds isolated from Piper crassinervium against Trypanosoma cruzi

This study describes the antichagasic potential of five compounds isolated from leaves of Piper crassinervium (Piperaceae). Two prenylated benzoic acid derivatives, one prenylated hydroquinone and two flavanones, were evaluated. The in vitro trypanocidal activity was determined against epimastigote forms of Trypanosoma cruzi (Y strain), the etiologic agent of Chagas disease. The most active compound was the prenylated hydroquinone [1,4-dihydroxy-2-(3(0),7(0)-dimethyl-1(0)-oxo-2(0)-E,6(0)-octadienyl)benzene] with an IC(50) value of 6.10 microg mL(-1), which was in the same order of activity if compared with the positive control benznidazole (IC(50) = 1.60 microg mL(-1)). This is the first report of trypanocidal activity for prenylated hydroquinone and benzoic acid derivatives.     

Chemical composition and In vitro antioxidant and antidiabetic activities of Eucalyptus Camaldulensis Dehnh. essential oil

The present study was designed to determine the composition of the essential oil of Eucalyptus camaldulensis Dehnh. leaves and to examine its in vitro antioxidant and antidiabetic activities. The chemical composition of the essential oil from Eucalyptus camaldulensis Dehnh. leaves was analyzed by GC/GC-MS, twenty-nine compounds representing 99.10% of the total oil were identified. The major components of the oil were p-cymene (68.43%), 1,8-cineole (13.92%), 1-(S)-α-pinene (3.45%) and R-(+)- limonene (2.84%). The antioxidant features of the essential oil were evaluated using inhibition of 2,2-diphenyl-1-picrylhydrazyl, hydroxyl, and superoxide radicals, inhibition of hydrogen peroxide and lipid peroxidation assays. We also studied α-amylase and α-glucosidase inhibition in vitro to assess the antidiabetic properties of the essential oil. Both α-amylase and α-glucosidase were inhibited by a non-competitive mechanism.     

Efficient separation of Cinnamomum camphora leaf essential oil and in vitro evaluation of its antifungal activity

Cinnamomum camphora leaf essential oil (CEO) was extracted using enzymatic-ultrasound pretreatment followed by microwave assisted extraction (EUP-MAE) method and simultaneously studied as a mycelial growth inhibitor against five important pathogens which cause potato dry rot. The optimum EUP-MAE conditions with a real CEO yield of 19.23 ± 0.12 mg/g were obtained through Plackett–Burman design and Box–Behnken design as follows: 3 % of enzyme dosage, 2 h of pretreatment time, 5 of pH, 210 W of ultrasound power, 50 °C pretreatment temperature, 16 mL/g of water to solid ratio, 30 min of microwave time and 500 W of microwave power. Compared to the reference methods, EUP-MAE possessed a highest CEO yield than these of ultrasound-microwave assisted extraction (U-MAE) and traditional hydrodistillation (HD). Gas chromatography-mass spectrometry (GC–MS) analysis demonstrated that eucalyptol, camphor, and α-terpineol were the three main constituents of CEO. Results from in vitro antifungal activity assay revealed that the mycelial growths of all the five tested Fusarium solani, Fusarium culmorum, Fusarium trichothecioides, Fusarium sporotrioides, and Fusarium avenaceum were apparently affected by CEO. These findings not only provide a potential paradigm for the separation of plant essential oil, but also guarantee a promising utilization of the CEO for potato protection to control the Fusarium spp.     

Comparison of essential oil components and in vitro anticancer activity in wild and cultivated Salvia verbenaca

The objectives of our research were to study the chemical composition and the in vitro anticancer effect of the essential oil of Salvia verbenaca growing in natural sites in comparison with those of cultivated (Sc) plants. The oil from wild (Sw) S. verbenaca presented hexadecanoic acid (23.1%) as the main constituent, while the oil from Sc plants contained high quantities of hexahydrofarnesyl acetone (9.7%), scarce in the natural oil (0.7%). The growth-inhibitory and proapoptotic effects of the essential oils from Sw and Sc S. verbenaca were evaluated in the human melanoma cell line M14, testing cell vitality, cell membrane integrity, genomic DNA fragmentation and caspase-3 activity. Both the essential oils were able to inhibit the growth of the cancer cells examined inducing also apoptotic cell death, but the essential oil from cultivated samples exhibited the major effects.     

In vitro antibacterial activity of some Iranian medicinal plant extracts against Helicobacter pylori

Helicobacter pylori infection causes lifelong chronic gastritis, which can lead to peptic ulcer, mucosa-associated lymphoid tissue (MALT) lymphoma and gastric cancer. The growing problem of antibiotic resistance by the organism demands the search for novel candidates from plant-based sources. In the present study, we evaluated the in vitro anti-H. pylori activity of some selected medicinal plants on clinical isolates of H. pylori. Gastric biopsy samples were obtained from patients presenting with gastroduodenal complications. Helicobacter pylori was isolated from the specimens following standard microbiology procedures. The disc-diffusion method was used to determine the susceptibility of three H. pylori isolates to methanol extracts of 23 Iranian plants. All tests were performed in triplicate. Among them, the extracts of Punica granatum and Juglans regia had remarkable anti-H. pylori activity with mean of inhibition zone diameter of 39 and 16?mm at 100?μg?disc?1, respectively. In view of the results obtained with P. granatum (pomegranate), the peel extracts of nine cultivars of pomegranate (Shirin-e-Pust Sefid, Agha Mohammad Ali-e-Shirin, Sefid-e-Shomal, Sefid-e-Torsh, Shirin-e-Malase, Tabestani-e-Torsh, Shirin-e-Saveh Malase, Alak-e-Shirin, Pust Siyah) were further assayed against the clinical isolates of H. pylori. The results revealed that all Iranian pomegranate cultivars, except for Alak-e-Shirin, showed significant in vitro anti-H. pylori activity against the clinical isolates of H. pylori (mean of inhibition zone diameter ranging from 16 to 40 mm at 50 μg disc?1).     

In vitro antimicrobial activity of Pistacia lentiscus L. edible oil and phenolic extract

Pistacia lentiscus L. is known in some Tunisian forest area by its fixed oil used in traditional medicine as an antiseptic product. This investigation is the first to study the antimicrobial activity of P.lentiscus edible oil and its phenolic extract. Oil was extracted from fruits harvested from six provenances located in Tunisia. The antimicrobial activity was tested using disc diffusion assay and the broth dilution method. Kbouch and Sidi Zid oils were most efficient (p < 0.003) against, respectively, Staphylococcus aureus and Aspergillus niger with an inhibition zone of 9.33 mm. The phenolic extract had the largest spectrum of sensitive microorganisms. The minimum inhibitory concentration and minimum bactericidal concentration results showed that all strains were inhibited by both oil and extract.     

Chemical composition and in vitro antimicrobial activity of the essential oil of the flowers of Tridax procumbens

The essential oil of the flowers of Tridax procumbens L. was obtained by hydro-distillation and analyzed by gas chromatography equipped with a flame ionization detector (GC-FID) and gas chromatography coupled with mass spectrometry (GC/MS). Twenty-six compounds were identified, which comprised 90.6% of the total constituents. The most abundant compound was (Z)-falcarinol (25.9%), followed by alpha-selinene (15.3%), limonene (8.3%) and zerumbone (4.3%). Antimicrobial activity was tested against six Gram-positive and eight Gram-negative bacteria, and three fungi. The oil was active against the tested Gram-positive bacteria at a concentration range of 0.14 +/- 0.03 - 0.57 +/- 0.05 mg/mL, while 0.67 +/- 0.12 - 4.58 +/- 0.41 mg/mL was effective against the studied Gram-negative bacteria. Remarkable antifungal activity was found against the tested fungi at a concentration range of 0.06 +/- 0.008 - 0.10 +/- 0.01 mg/mL.