Chemical composition and antifungal activity of essential oil ofHyssopus officinalisL. from Bulgaria against clinical isolates ofCandidaspecies

The Genus Hyssopus: Traditional Use, Phytochemicals and Pharmacological Properties

According to modern concepts, the genus Hyssopus L. includes seven plant species (Hyssopus ambiguus (Trautv.) Iljin ex Prochorov. & Lebel; Hyssopus cuspidatus Boriss; Hyssopus latilabiatus C.Y.Wu & H.W. Li; Hyssopus macranthus Boriss.; Hyssopus officinalis L.; Hyssopus seravschanicus (Dubj.) Pazij; Hyssopus subulifolius (Rech.f.) Rech.f.). The plants are rich in various groups of biologically active substances with a wide spectrum of pharmacological action. This review presents a modern comprehensive overview of the botanical research, extraction methods, chemical composition and pharmacological activity of plants of the genus Hyssopus L. As a result of the review, it was established that the chemical composition of plant extracts of the genus Hyssopus L. depends on various factors (place of growth, weather conditions, chemotypes, extraction methods, etc.). For the further use of the plants, the extraction methods and low-molecular metabolites isolated from them (mono- and sesquiterpenoids, flavonoids, alkaloids, etc.) are discussed. The data from the review provide an assessment of the relevance.

Iranian Traditional Medicine (ITM) and Natural Remedies for Treatment of the Common Cold and Flu

Traditional Iranian medicine is usually used for both prevention and relief of cold and flu symptoms in China, Iran, and many other Asian countries all over the world. There are 4 kinds of influenza viruses. Unlike type B, which may cause seasonal epidemics, type A viruses can cause pandemics, and influenza C may lead to mild human infection with little public health effects. A literature review was done by using multiple databases such as ISI Web of knowledge, PubMed, Science Direct and Google Scholar. The most notable antiviral medicinal plants for flu and cold are honeysuckle flowers, thyme leaf, green chiretta, andrographis, peppermint oil and leaf and calendula. The most important expectorant medicinal plants for cold and flu are snake root, tulsi, licorice root, slippery elm, clove, and sage leaf. Recommended immunostimulant medicinal plants for cold and flu are eucalyptus, Echinacea root, ginseng, garlic, slippery elm, marshmallow, Usnea lichen, Isatis root, ginger root, and myrrh resin. Iranian traditional medicine, which is one of the oldest schools of traditional medicine, is one of the main concepts of disease and health, and it can be considered as an important complementary and alternative medicine, as in some cases, modern medicine has many side effects, low efficiency, and high costs. Medicinal plants and herbs, which are included in many traditional systems, have significant and promising bioactive components in organic life.

RNA-Seq-Based Transcriptomics and GC-MS Quantitative Analysis Reveal Antifungal Mechanisms of Essential Oil of Clausena lansium (Lour.) Skeels Seeds against Candida albicans

Infections caused by Candida albicans (C. albicans) and increasing resistance to commonly used drugs lead to a variety of mucosal diseases and systemic infectious diseases. We previously confirmed that the essential oil of Clausena lansium (Lour.) Skeels seeds (CSEO) had antifungal activity against C. albicans, but the detailed mechanism between the chemical components and antifungal activity is unclear. In this study, a quantitative analysis of five volatile components of CSEO, including sabinene, α-phellandrene, β-phellandrene, 4-terpineol, and β-caryophyllene, was carried out using the gas chromatography-mass spectrometry (GC-MS) method. Both the broth dilution and kinetic growth methods proved that the antifungal activity of CSEO against fluconazole-resistant C. albicans was better than that of its main components (sabinene and 4-terpineol). To further investigate the inhibitory mechanism, the transcriptional responses of C. albicans to CSEO, sabinene, and 4-terpineol treatment were determined based on RNA-seq. The Venn diagram and clustering analysis pattern of differential expression genes showed the mechanism of CSEO and 4-terpineol's anti-C. albicans activity might be similar from the perspective of the genes. Functional enrichment analysis suggested that CSEO regulated adherence-, hyphae-, and biofilm-formation-related genes, which may be CSEO's active mechanism of inhibiting the growth of fluconazole-resistant C. albicans. Overall, we preliminarily revealed the molecular mechanism between the chemical components and the antifungal activity of CSEO against C. albicans. This study provides new insights to overcome the azole resistance of C. albicans and promote the development and application of C. lansium (Lour.) Skeels seeds.

Metabolomic Profile of Volatile Organic Compounds from Leaves of Cashew Clones by HS-SPME/GC-MS for the Identification of Candidates for Anthracnose Resistance Markers

Anthracnose caused by Colletotrichum gloeosporioides affects the leaves, inflorescences, nuts, and peduncles of cashew trees (Anacardium occidentale). The use of genetically improved plants and the insertion of dwarf cashew clones that are more resistant to phytopathogens are strategies to minimize the impact of anthracnose on cashew production. However, resistance mechanisms related to the biosynthesis of secondary metabolites remain unknown. Thus, this study promoted the investigation of the profile of volatile organic compounds of resistant cashew clone leaves ('CCP 76', 'BRS 226' and 'BRS 189') and susceptible ('BRS 265') to C. gloeosporioides, in the periods of non-infection and infection of the pathogen in the field (July-December 2019 - Brazil). Seventy-eight compounds were provisionally identified. Chemometric analyses, such as Principal Component Analysis (PCA), Discriminating Partial Least Squares Analysis (PLS-DA), Discriminating Analysis of Orthogonal Partial Least Squares (OPLS-DA), and Hierarchical Cluster Analysis (HCA), separated the samples into different groups, highlighting hexanal, (E)-hex-2-enal, (Z)-hex-2-en-1-ol, (E)-hex-3-en-1-ol, in addition to α-pinene, α-terpinene, γ-terpinene, β-pinene, and δ-3-carene, in the samples of the resistant clones in comparison to the susceptible clone. According to the literature, these metabolites have antimicrobial activity and are therefore chemical marker candidates for resistance to C. gloeosporioides in cashew trees.

Chemical profile, antimicrobial activity, and leaf anatomy of Adenophyllum porophyllum var. cancellatum

Adenophyllum porophyllum var. cancellatum, known as “árnica del monte” in Mexico, is an aromatic annual plant belonging to the Asteraceae family that grows from southern Arizona to central Mexico. The aerial parts of the plant are used in traditional medicine to treat skin diseases such as irritations, infections, and wounds. In this study, the essential oil of this plant was characterized, and its antimicrobial activity was evaluated. This species has large glands in its leaves; therefore, for quality control purposes, an anatomical study of the leaves was performed. The essential oil was isolated from the aerial parts of the plant through hydro-distillation and analyzed using a gas chromatography/mass spectrometry (GC/MS) system. Its anti-yeast activity was evaluated against three Candida species and ten bacterial strains using the disk diffusion technique. The minimum inhibitory concentration (MIC), minimum fungicidal concentration (MFC), and minimum bactericidal concentration (MBC) were determined using broth microdilution. Anatomical study was performed on the middle part of the leaf. A yield of 0.5% of the essential oil was obtained from the herb, and Eighteen compounds in the essential oil were identified, within them trans pinocamphone (29.5%), limonene (24.7%), pinocarvone (21.8%), and cis pinocamphone (8.0%) were the main components. The inhibition zones were between 10 mm and 20 mm, and the MIC and MFC against the three Candida species ranged from 60 to 500 μg/ml. The leaf anatomy showed anisocytic stomata, simple and glandular trichomes of different types, and large and elliptical-shaped lysigenous glands, which can be used for taxonomic identification. The A. porophyllum var. cancellatum essential oil can serve as an alternative source of natural antimicrobial agents as an affordable approach to control infectious diseases. This is the first study that reports the chemical composition and antimicrobial activity of the essential oil, as well as the leaf anatomy of this species.

Characteristics of Selected Silphium Species as Alternative Plants for Cultivation and Industry with Particular Emphasis on Research Conducted in Poland: A Review

This article reviews the available research results of selected species of the genus Silphium L. (Asteraceae) as alternative plants for crops and industry. Silphium species have valuable qualities across a wide range of uses, which is very important in considering plant resources as a green alternative to a sustainable future. Species of the genus Silphium are tall perennials found in fields, prairies, open forests, and groves in the central and eastern parts of the United States and Canada. Various tribes of Native North American used Silphium for medicinal purposes. The cup plant Silphium perfoliatum L. is the most popular species of the genus Silphium due to its attractive ornamental, honey−giving, healing, and forage qualities. As the literature review shows, species of the genus Silphium are characterized by a high production potential in terms of yields and contain significant amounts of nutrients, i.e., carbohydrates, proteins, and L-ascorbic acid, as well as minerals and biologically active substances, e.g., terpenoids and essential oils, flavonoids, phenolic acids, and oleanosides. In addition, the research confirmed the possibility of using Silphium for fodder, as honeybee forage, phytoremediation plants, for reclamation of degraded land, as plants for energy purposes (biomass, biogas), and as plants that provide components with antimicrobial activity. This review largely takes into account many years of research experience conducted in Poland.

Allelopathic Effects of Essential Oils on Seed Germination of Barley and Wheat

In this study, we evaluated the allelopathic effects of essential oils (EOs) from six different plant species, namely, lavender (Lavandula angustifolia), hyssop (Hyssopus officinalis), English thyme (Thymus vulgaris), lovage (Levisticum officinale), costmary (Chrysanthemum balsamita), and cumin (Cuminum cyminum), on seed germination and seedling growth of barley (Hordeum vulgare) and wheat (Triticum aestivum). The main constituents of the EOs of L. angustifolia were 47.0% linalool acetate and 28.4% linalool; H. officinalis' main constituents were 39.8% cis-pinocamphone, 9.8% trans-pinocamphone, 11.4% β-pinene, and 7.5% β-phellandrene; T. vulgaris' were 38.2% para-cymene, 25.6% thymol, and 13.6% γ-terpinene; L. officinale's were 64.8% α-terpinyl acetate and 14.7% β-phellandrene; C. balsamita's were 43.7% camphor, 32.4% trans-thujone, and 11.6% camphene; C. cyminum's were 49.6% cumin aldehyde, 10.4% para-cymene, 11.6% α-terpinen-7-al, and 9.1% β-pinene. All six EOs exhibited an allelopathic effect and suppressed the seed germination and seedling development of wheat and barley; however, the concentrations that exhibited a suppressing effect were different among the plants. C. cyminum EO completely suppressed both barley and wheat germination at 10-, 30-, and 90-µL application rates, making it the most effective treatment among the tested EOs. C. balsamita's and H. officinalis' EOs at 30 and 90 µL application rates completely suppressed barley and wheat radicles per seed, radicle length (mm), seedling height (mm), and germination (%). L. angustifolia's EOs at 30- and 90-µL and T. vulgaris' EO at 90 µL application rates also completely suppressed barley and wheat radicles per seed, radicle length (mm), seedling height (mm), and germination (%). C. balsamita's, H. officinalis', L. angustifolia's, and T. vulgaris' EOs at a 10 µL application rate reduced barley radicle length, seedling height, and % germination relative to the control. Wheat seed germination % was completely suppressed by the application of L. angustifolia's and T. vulgaris' EOs at 30 and 90 µL, while T. vulgaris' EO at 10 µL rate reduced the germination relative to the control. Interestingly, C. balsamita and H. officinalis at 10 µL did not reduce wheat germination; however, they did reduce the number of radicles per seed, radicle length (mm), seedling height (mm), germination (%), and vigor index. Furthermore, L. officinale's EO reduced the measured indices (radicles per seed, radicle length, seedling height, and vigor index) at the 10, 30, and 90 µL application rates relative to the non-treated control; however, none of the application rates of L. officinale's EO had a suppression effect on wheat germination. This study demonstrated the allelopathic effects of the EOs of six different herbal plant species on seed germination of barley and winter wheat. The results can be utilized in the development of commercial products for controlling pre-harvest sprouting of wheat and barley. Further research is needed to verify the results under field conditions.

Qualitative and quantitative analysis of diosmin content of hyssop (Hyssopus officinalis) in response to salinity stress

Hyssop (Hyssopus officinalis L.) is a perennial subshrub, which is distributed across the eastern Mediterranean region to central Asia. One of the most important bioactive compounds of hyssop is diosmin, a flavone glycoside of diosmetin, with application in the field of cardiovascular therapy. Salinity as one of the most essential environmental stress factors is able to alter secondary metabolite content in plants. Therefore, we aimed to investigate the effect of salinity on the levels of total flavonoid content and diosmin in hyssop. Accordingly, salinity stress was imposed by watering plants with four different concentrations of sodium chloride (NaCl) (50, 100, 150 and 200 mM) for 4 weeks. High-performance liquid chromatography (HPLC) method was used for purification of diosmin from dried leaves and measurement of it in dried shoots. Nuclear magnetic resonance (NMR) spectroscopy was applied for determination of the structure of diosmin. The obtained results showed that high salinity levels lead to a higher amount of total flavonoid and diosmin content in treated plants. Although alteration in diosmin content was not significant in treatments up to 100 mM NaCl, higher amounts of diosmin were observed in 150 and 200 mM NaCl salinity levels. We concluded that the contents of total flavonoid and diosmin were significantly elevated after exposure of hyssop plants to salt stress conditions.

Weather Conditions Influence on Hyssop Essential Oil Quality

This paper is a study of the chemical composition of Hyssopus officinalis ssp. officinalis grown during three years (2017–2019) at the Institute of Field and Vegetable Crops Novi Sad (Vojvodina Province, Serbia). Furthermore, comparisons with ISO standards during the years were also investigated, as well as a prediction model of retention indices of compounds from the essential oils. An essential oil obtained by hydrodistillation and analysed by GC-FID and GC-MS was isopinocamphone chemotype. The gathered information about the volatile compounds from H. officinalis was used to classify the samples using the unrooted cluster tree. The correlation analysis was applied to investigate the similarity of different samples, according to GC-MS data. The quantitative structure–retention relationship (QSRR) was also employed to predict the retention indices of the identified compounds. A total of 74 experimentally obtained retention indices were used to build a prediction model. The coefficient of determination for the training cycle was 0.910, indicating that this model could be used for the prediction of retention indices for H. officinalis essential oil compounds.

Antioxidant, Antigenotoxic and Cytotoxic Activity of Essential Oils and Methanol Extracts of Hyssopus officinalis L. Subsp. aristatus (Godr.) Nyman (Lamiaceae)

Hyssopus officinalis L. is a well-known aromatic plant used in traditional medicine and the food and cosmetics industry. The aim of this study is to assess the antioxidant, genotoxic, antigenotoxic and cytotoxic properties of characterized hyssop essential oils and methanol extracts. Chemical composition was analyzed by gas chromatography - mass spectrometry (GC-MS) and liquid chromatography with diode array detection and mass spectrometry (LC-DAD-MS), respectively. Antioxidant activity was examined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing/antioxidant power (FRAP) tests; genotoxic and antigenotoxic activity were examined by the comet assay, while cytotoxicity was evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide dye (MTT) test against tumor cell lines (SW480, MDA-MB 231, HeLa) and non-transformed human lung fibroblast cell lines (MRC-5). The essential oils were rich in monoterpene hydrocarbons (e.g., limonene; 7.99–23.81%), oxygenated monoterpenes (1,8-cineole; 38.19–67.1%) and phenylpropanoids (methyl eugenol; 0.00–28.33%). In methanol extracts, the most abundant phenolics were chlorogenic and rosmarinic acid (23.35–33.46 and 3.53–17.98 mg/g, respectively). Methanol extracts expressed moderate to weak antioxidant activity (DPPH IC₅₀ = 56.04–199.89 µg/mL, FRAP = 0.667–0.959 mmol Fe²⁺/g). Hyssop preparations significantly reduced DNA damage in human whole blood cells, induced by pretreatment with hydrogen peroxide. Methanol extracts exhibited selective and potent dose- and time-dependent activity against the HeLa cell line. Results of the current study demonstrated notable H. officinalis medicinal potential, which calls for further investigation.

Chemical characterization and bioactivity of the essential oil from Santolina insularis, a Sardinian endemism

Santolina insularis is a Sardinian endemism that is widely used in traditional medicine. The essential oil was obtained with a yield of 2.7% and is mainly characterized by β-phellandrene (22.6%), myrcene (11.4%) and artemisia ketone (7.6%). The oil significantly reduced NO production without affecting macrophages viability. In addition, it substantially inhibited the expression of two key pro-inflammatory enzymes, iNOS and COX-2 (71% and 25% at 0.54 mg/mL). Furthermore, the oil had a promising antifungal activity being Cryptococcus neoformans (MIC = 0.13 mg/mL) and the majority of dermatophytes (MIC = 0.13 mg/mL) the most susceptible fungi. Moreover, it significantly decreased the yeast-to-hypha transition (80% inhibition at 0.13 mg/mL) on C. albicans long before showing inhibitory effects. Overall, these results show that S. insularis could be applied in the treatment of fungal infections and associated inflammatory response.

Chemical composition and in vitro activity of Origanum vulgare L., Satureja hortensis L., Thymus serpyllum L. and Thymus vulgaris L. essential oils towards oral isolates of Candida albicans and Candida glabrata

The purpose of this research was to investigate the chemical composition of essential oils (EOs) from: Origanum vulgare L., Satureja hortensis L., Thymus serpyllum L. and Thymus vulgaris L. (Lamiaceae) cultivated in Poland, and to study their antifungal activity towards clinical isolates of oral Candida spp. The hydrodistilled essential oils were analyzed using the GC-MS method. The antifungal activity was evaluated in vitro against oral isolates and reference strains of Candida albicans and C. glabrata, using the broth microdilution method according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) and Clinical and Laboratory Standards Institute (CLSI) guidelines, allowing for estimation of minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC). GC-MS analysis revealed that carvacrol was the main EO compound in oregano and summer savory, while thymol and linalool were the major ingredients of thyme and wild thyme oils, respectively. The EOs possessed fungicidal activity against C. albicans and C. glabrata, including oral isolates, with MIC = 125 – 2000 mg/L, MFC = 250 – 4000 mg/L and MFC/MIC = 1 – 4, depending on the yeast and plant species. The most active was thyme oil – with MIC = 125 – 500 mg/L, MFC = 250 – 500 mg/L and MFC/MIC = 1 – 2.

Essential Oils of Lamiaceae Family Plants as Antifungals

The incidence of fungal infections has been steadily increasing in recent years. Systemic mycoses are characterized by the highest mortality. At the same time, the frequency of infections caused by drug-resistant strains and new pathogens e.g., Candida auris increases. An alternative to medicines may be essential oils, which can have a broad antimicrobial spectrum. Rich in the essential oils are plants from the Lamiaceae family. In this review are presented antifungal activities of essential oils from 72 Lamiaceae plants. More than half of these have good activity (minimum inhibitory concentrations (MICs) < 1000 µg/mL) against fungi. The best activity (MICs < 100) have essential oils from some species of the genera Clinopodium, Lavandula, Mentha, Thymbra, and Thymus. In some cases were observed significant discrepancies between different studies. In the review are also shown the most important compounds of described essential oils. To the chemical components most commonly found as the main ingredients include β-caryophyllene (41 plants), linalool (27 plants), limonene (26), β-pinene (25), 1,8-cineole (22), carvacrol (21), α-pinene (21), p-cymene (20), γ-terpinene (20), and thymol (20).

Phytochemical Investigations of Laurel Fruits (Laurus nobilis)

Bay laurel ( Laurus nobilis L.) is an evergreen tree. The objective of this study was to determine the chemical composition (polyphenols, essential oil [EO], lipid fraction, cellulose, and protein content) of laurel fruits collected from Greece (Mount Athos) and Georgia (the village of Meria), and to evaluate the antimicrobial activity of laurel fruit EOs. The major phenolic acids in the fruits from Greece were p-coumaric acid (free 261.6 µg/g) and vanillic acid (free 253.1 µg/g and conjugated 925.8 µg/g). The major phenolic acids in fruits from Georgia were vanillic acid (free 105.6 µg/g and caffeic acid [conjugated 439.2 µg/g], and syringic acid [conjugated 390.7 µg/g]). The laurel fruit EOs from Greece (1.4% content) and Georgia (1.6%) had distinct composition. Monoterpene hydrocarbons were the dominant group of compounds in the EOs, with 49.7% in the EO from Greece and 68.7% in the EO from Georgia. The major constituents of the fruit EO from Greece were 1,8-cineole (18.2%), α-phellandrene (15.0 %), β-pinene (9.4%), and α -pinene (9.1%), whereas the ones from Georgia were trans-β-ocimene (59.4%) and 1,8-cineole (7.6%). Laurel fruit EO from Greece and Georgia demonstrated low to moderate antimicrobial activity against pathogenic and spoilage microorganisms and the dimorphic yeast Candida albicans. The main fatty acids (FAs) in the lipid fractions were oleic, palmitic, and linoleic; there were differences in FA composition between the shells and the seeds of the fruits from the two countries. γ-Тocopherol predominated in the tocopherol fraction of the lipids from fruits shells and seeds from Greece (65.3% and 54.4%, respectively), whereas β-tocopherol predominated in fruits shells and seeds from Georgia (93.7% and 45.6%, respectively). Currently underutilized, the laurel fruits from both Greece and Georgia contain various valuable compounds that may potentially be used for perfumery, cosmetic, and pharmaceutical applications.

Effects of Ultrasound Technique on the Composition of Different Essential Oils

The objective of the experiment was to investigate the stability of the composition of selected essential oils in the model systems containing methanol and hexane solutions which were treated with ultrasound. Solutions of the oils, with a concentration of 90 mg/ml, were subjected to the effect of ultrasounds with a frequency of 20 kHz and an output power of 200 W for periods of 2 min and 10 min at 50% and 80% power. The experiment has shown no significant effect on the composition of the essential oils resulting from the applied parameters of the process in the tested model systems. The study indicates that the sonication parameters adopted in the experiment can be applied in the case of analogous systems containing essential oils in their composition.

Extraction of Hyssopus officinalis L. essential oil using instant controlled pressure drop process

To determine the optimum condition for the extraction of Hyssopus officinalis L. essential oil (EO) by instant controlled pressure drop (in French: Détente Instantanée Contrôlée or DIC), the influential parameters of pressure, heating time per cycle, number of cycles, mean particle diameter of the herb, and water concentration in the steam generator feed were evaluated using response surface methodology (RSM). The impact of using an ethanol-water mixture to generate the required vapor in the DIC process on EO extraction was investigated. The optimum condition was found to be at pressure = 1 bar, heating time = 100 s, cycles = 12, particle diameter = 1 mm, and water concentration = 80 v%. The addition of ethanol turned out to be more efficient at higher heating times and cycle numbers. The optimum yield in DIC was highest compared with hydrodistillation (HD), ultrasound-assisted extraction (UAE), and Soxhlet (SOX) methods; their values, expressed as total area percentages per internal standard area percentage, were 39.04, 10.98, 1.58, and 7.71, respectively. Comparison of the four methods also indicated that the DIC-EO was of a superior quality. The analysis of the DIC-treated residual herb in the optimum experiment revealed that unlike the low amount of valuable oxygenated monoterpenes, the availability of sesquiterpenes increased, which proved that DIC performs selectively while extracting more valuable EO components. The DIC-EO and its extract were examined for total phenolic content (TPC) and antioxidant activity using Folin-Ciocalteu and DPPH assay, respectively. Comparison of these results with those obtained from HD demonstrated higher TPC and antioxidant activity of the DIC-EO. Moreover, scanning electron microscopy (SEM) of the raw material and residual herb in the optimum experiment showed significant structure modifications induced by the DIC process.

Chemical composition and microbiological evaluation of essential oil from Hyssopus officinalis L. with white and pink flowers

Hyssopus officinalis L. is a common plant that is most usually found in three color forms - f. cyaneus (blue), f. ruber Mill. (purple/pink) and f. albus Alef (white). In the present work, we evaluated the chemical composition and antimicrobial activity of essential oils obtained from Polish-sourced white- and pink-flowered H. officinalis. Gas chromatography-mass spectrometry analysis of the essential oil has shown that both forms of color have a different content of main components. The principle essential oil component of white-flowered H. officinalis L. was pinocamphone (51%), while pink-flowered H. officinalis L. contained almost equal amounts of pinocamphone (28.8%) and isopinocamphone (21.9%). Of note, the essential oil of the pink form was more active against Grampositive bacteria, especially against Bacillus subtilis.

The effect of isabelin, a sesquiterpene lactone from Ambrosia artemisiifolia on soil microorganisms and human pathogens

Ambrosia artemisiifolia L. (common ragweed) is an invasive weed, which is well known for the strong allergenic effect of its pollen as well as for its invasiveness and impact in crop fields (e.g. causing yield losses). This species produces a broad range of sesquiterpenoids. In recent years, new bioactive molecules have been discovered in this plant, e.g. isabelin, a sesquiterpene dilactone. The bioactivity of isabelin has been already demonstrated on allergy-related receptors and its inhibitory effect on seeds of various plant species. Isabelin was tested for potential antimicrobial effects by using a selection of soil-borne bacteria and fungi and three human pathogens as model organisms. For the majority of microorganisms tested, no antimicrobial activity of isabelin was observed. However, isabelin revealed strong antimicrobial activity against the Gram-positive soil bacterium Paenibacillus sp. and against the Gram-positive, multidrug-resistant Staphylococcus aureus. The observed inhibitory activity of isabelin can enlighten the importance to study similar compounds for their effect on human pathogens and on soil and rhizosphere microorganisms.

Effect of Plant Essential Oils against Rophalosiphum padi on Wheat and Barley

The aim of the present study was to evaluate the effect of six EOs against Rhopalosiphum padi L. (Homoptera: Aphididae). This aphid is one of the most important cereal pests worldwide. EOs used in this study were from cumin ( Cuminum cyminum L.; Apiaceae), hyssop ( Hyssopus officinalis L.; Lamiaceae), costmary ( Tanacetum balsamita L. syn. Chrysanthemum balsamita L. Baill; Asteraceae), lovage ( Levisticum officinale W.D.J. Koch; Apiaceae), lavander ( Lavandula angustifolia Mill; Lamiaceae) and thyme ( Thymus vulgaris L.; Lamiaceae). Cultivar ORCF-10, a soft white winter wheat ( Triticum aestivum L.) cultivar and barley ( Hordeum vulgare L.) cv. ‘Alba’ were selected for the bioassays. Each EO was diluted with acetone (w/v) at different concentrations ranging from 0.1 % to 1.0 %. Number of R. padi landing on treated or untreated leaves was counted 24 h after the initial aphid transfer. In general, the repellency effect increased as the concentration of EOs increased regardless of treatments with the exception of lovage. Regardless of the substrate and treatment, lower numbers of aphids were observed on treated leaves at higher concentrations compared to the untreated control stressing the repellency effect. This study demonstrated that the EOs of cumin, hyssop, costmary, lavender, and thyme may have potential for aphids control.

Plants from Lamiaceae family as source of antifungal molecules in humane and veterinary medicine

This work aimed to review the main plants of Lamiaceae family with activity against pathogenic fungi of medical and veterinary interest. Published studies in the main international databases between January 2002 and June 2016 showed that 55 botanical species belonging to 27 genus presented antifungal activity in different forms of extractions, mainly essential oils. Pathogenic fungi of Aspergillus spp., Candida spp., Malassezia spp., Cryptococcus spp., Sporothrix spp., Microsporum spp., Trichophyton spp. and Epidermophyton spp. genus were in vitro sensitive to several plants of Lamiaceae family. Chemical molecules isolated were described as promising use as antifungals in mycoses, highlighting estragole, 1,8-cineole, terpineol-4, γ-terpinene, among others. However, it should be alert to need of universal standardization in the laboratories tests with natural products.