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Mint flavorings are widely used in confections, beverages, and dairy products. For the first time, mint flavoring composition of mint candies and food supplements (n = 45), originating from 16 countries, as well as their antibacterial properties, was analyzed. The flavorings were isolated by Marcussonʼs type micro-apparatus and analyzed by GC-MS. The total content of the mint flavoring hydrodistilled extracts was in the range of 0.01 – 0.9%. The most abundant compounds identified in the extracts were limonene, 1,8-cineole, menthone, menthofuran, isomenthone, menthol and its isomers, menthyl acetate. The antimicrobial activity of 13 reference substances and 10 selected mint flavoring hydrodistilled extracts was tested on Escherichia coli and Staphylococcus aureus by broth dilution method. Linalool acetate and (−)-carvone, as most active against both bacteria, had the lowest MIC90 values. (+)-Menthyl acetate, (−)-menthyl acetate, and limonene showed no antimicrobial activity. Three of the tested extracts had antimicrobial activity against E. coli and 8 extracts against S. aureus. Their summary antimicrobial activity was not always in concordance with the activities of respective reference substances. [ABSTRACT FROM AUTHOR]

In a previous work, we have demonstrated that MINTHOSTACHYS VERTICILLATA essential oil has immunomodulatory effects IN VITRO on cells from allergic patients. Here we characterized main components of M. VERTICILLATA essential oil and also tested if these compounds modulate IN VITRO and IN VIVO the immediate-type allergic reaction. Gas chromatography was used to identify main components of the essential oil. Pulegone (63.4 %), menthone (15.9 %), and limonene (2.1 %) were found as main classes. IL-13 levels were evaluated from lymphocytes cultures stimulated with allergen alone or combined with monoterpenes. All compounds stimulated cell proliferation but, interestingly, promoted a reduction of IL-13 values, limonene and the mixture of the three compounds being the most active. β-Hexosaminidase release was determined from basophils to which essential oil or monoterpenes were added. We observed that, whichever combination of monoterpenes was used, β-hexosaminidase release was diminished in all cases. Obtained values were even lower than those of antiallergic drug desloratadine. Essential oil and limonene inhibited mast cell activation and degranulation in the skin when testing passive cutaneous anaphylaxis, limonene being the most active. In conclusion, limonene was the compound that showed the most potent immunomodulatory activity. This fact suggests that it constitutes a promising natural alternative for a novel treatment of allergic diseases. [ABSTRACT FROM AUTHOR]

Agastache rugosa Kuntze (Lamiaceae; Labiatae), a medicinal and functional herb used to treat gastrointestinal diseases, grows well both on islands and inland areas in South Korea. Thus, we aimed to reveal the morphological and micromorphological differences between A. rugosa grown on island and inland areas and their pharmacological effects on gastritis in an animal model by combining morphological and mass spectrophotometric analyses. Morphological analysis showed that island A. rugosa had slightly smaller plants and leaves than inland plants; however, the density of all types of trichomes on the leaves, petioles, and stems of island A. rugosa was significantly higher than that of inland plants. The essential oil component analysis revealed that pulegone levels were substantially higher in island A. rugosa than in inland A. rugosa. Despite the differences between island and inland A. rugosa , treatment with both island and inland A. rugosa reduced gastric damages by more than 40% compared to the gastritis induction group. In addition, expression of inflammatory protein was reduced by about 30% by treatment of island and inland A. rugosa. The present study demonstrates quantitative differences in morphology and volatile components between island and inland plants; significant differences were not observed between the gastritis-inhibitory effects of island and inland A. rugosa , and the efficacy of island A. rugosa was found to be similar to that of A. rugosa grown in inland areas. [ABSTRACT FROM AUTHOR]

Seborrheic dermatitis is a chronic inflammatory disease caused by Malassezia yeast species that affects the regions of the body where the sebaceous glands are present. The combined use of different essential oils (EOs) can increase their spectrum of action. Thus, the present study aimed to evaluate the action of EOs alone and in combination with each other on M. furfur , in planktonic and biofilm form, and their anti-inflammatory and mutagenic potential, in addition to the effects on the viability of cells lines. Of the 40 evaluated EOs, 22 showed activity against M. furfur at 0.5 – 2.0 mg/mL concentrations. Among the most active species, a blend of essential oils (BEOs) composed of Cymbopogon martini (Roxb.) Will. Watson (MIC = 0.5 mg/mL) and Mentha × piperita L. (MIC = 1.0 mg/mL) was selected, which showed a synergistic effect against yeast when evaluated through the checkerboard assay. The fungicidal activity was maintained by the addition of anti-inflammatory oil from Varronia curassavica Jacq. to BEOs. The BEOs also showed activity in the inhibition of biofilm formation and in the eradication of the biofilm formed by M. furfur , being superior to the action of fluconazole. Furthermore, it did not show mutagenic potential and did not interfere with the cell viability of both evaluated cell lines (HaCaT and BMDMs). TNF- α levels were reduced only by C. martini ; however, this property was maintained when evaluating BEOs. BEOs had no effect on IL-8 levels. Thus, the BEOs may be indicated for alternative treatments against seborrheic dermatitis. [ABSTRACT FROM AUTHOR]

A key point in the biosynthesis of the antimalarial drug artemisinin is the formation of dihydroartemisinic aldehyde which represents the key difference between chemotype specific pathways. This key intermediate is the substrate for several competing enzymes, some of which increase the metabolic flux towards artemisinin, and some of which – as we show in the present study – may have a negative impact on artemisinin production. In an effort to understand the biosynthetic network of artemisinin biosynthesis, extracts of A.�annua flowers were investigated and found to contain an enzyme activity competing in a negative sense with artemisinin biosynthesis. The enzyme Red1 is a broad substrate oxidoreductase belonging to the short chain dehydrogenase/reductase family with high affinity for dihydroartemisinic aldehyde and valuable monoterpenoids. Spatial and temporal analysis of cDNA revealed Red1 to be trichome specific. The relevance of Red1 to artemisinin biosynthesis is discussed. [ABSTRACT FROM AUTHOR]

Administration of essential oils as natural plant products with antimicrobial activity might be an alternative to antibiotic treatment of bovine respiratory disease. The aim of this study was to analyse the in vitro antimicrobial activity of 11 essential oils against Pasteurella multocida isolated from the respiratory tract of calves using microdilution with determination of minimum inhibitory and bactericidal concentration as well as agar disc diffusion. Additionally, antimicrobial activity against Mannheimia haemolytica and bacteria in the Mannheimia clade was assessed by agar disc diffusion. Seven essential oil mixtures were also tested against all bacterial isolates. P. multocida was strongly inhibited by cinnamon cassia and lemongrass oil followed by coriander, winter savory, thyme, clove, and peppermint oil in the microdilution assays. Eucalyptus, wintergreen, spruce, and star anise oil showed lower activity. Comparison of both methods revealed an underestimation of cinnamon cassia oil activity by agar disc diffusion and conflicting results for wintergreen oil in microdilution, which precipitated in broth. Cinnamon cassia, thyme, wintergreen, lemongrass, and winter savory oil all showed strong antimicrobial activity against M. haemolytica. Bacteria in the Mannheimia clade were mostly inhibited by cinnamon cassia and thyme oil. Pasteurella isolates were more susceptible to inhibition by essential oils than Mannheimia isolates. Essential oil mixtures did not show stronger antibacterial activity than single essential oils. In conclusion, cinnamon cassia and lemongrass as well as coriander, winter savory, and thyme oil are promising candidates for treatment of P. multocida -associated bovine respiratory infections. [ABSTRACT FROM AUTHOR]

Medicinal plants for prophylaxis and therapy of common infectious diseases in poultry have been studied for several years. The goal of this review was to systematically identify plant species and evaluate their potential in prophylaxis and therapy of common diseases in poultry caused by bacteria and gastrointestinal protozoa. The procedure followed the recommendations of the PRISMA statement and the AMSTAR measurement tool. The PICOS scheme was used to design the research questions. Two databases were consulted, and publications were manually selected, according to predefined in- and exclusion criteria. A scoring system was established to evaluate the remaining publications. Initially, 4197 identified publications were found, and 77 publications remained after manual sorting, including 38 publications with 70 experiments on bacterial infections and 39 publications with 78 experiments on gastrointestinal protozoa. In total, 83 plant species from 42 families were identified. Asteraceae and Lamiaceae were the most frequently found families with Artemisia annua being the most frequently found plant, followed by Origanum vulgare. As compared to placebo and positive or negative control groups, antimicrobial effects were found in 46 experiments, prebiotic effects in 19 experiments, and antiprotozoal effects in 47 experiments. In summary, a total of 274 positive effects predominated over 241 zero effects and 37 negative effects. Data indicate that O. vulgare, Coriandrum sativum, A. annua, and Bidens pilosa are promising plant species for prophylaxis and therapy of bacterial and protozoal diseases in poultry. [ABSTRACT FROM AUTHOR]

The present study describes the antimicrobial activity and free radical scavenging capacity (RSC) of essential oils from Mentha aquatica L., Mentha longifolia L., and Mentha piperita L. The chemical profile of each essential oil was determined by GC-MS and TLC. All essential oils exhibited very strong antibacterial activity, in particularly against Esherichia coli strains. The most powerful was M. piperita essential oil, especially towards multiresistant strain of Shigella sonei and Micrococcus flavus ATTC 10 240. All tested oils showed significant fungistatic and fungicidal activity [expressed as minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) values, respectively], that were considerably higher than those of the commercial fungicide bifonazole. The essential oils of M. piperita and M. longifolia were found to be more active than the essential oil of M. aquatica. Especially low MIC (4 μL/mL) and MFC (4 μL/mL) were found with M. piperita oil against Trichophyton tonsurans and Candida albicans (both 8 μL/mL). The RSC was evaluated by measuring the scavenging activity of the essential oils on the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and OH radicals. All examined essential oils were able to reduce DPPH radicals into the neutral DPPH-H form, and this activity was dose-dependent. However, only the M. piperita oil reduced DPPH to 50 % (IC 50 = 2.53 μg/mL). The M. piperita essential oil also exhibited the highest OH radical scavenging activity, reducing OH radical generation in the Fenton reaction by 24 % (pure oil). According to GC-MS and TLC (dot-blot techniques), the most powerful scavenging compounds were monoterpene ketones (menthone and isomenthone) in the essential oils of M. longifolia and M. piperita and 1,8-cineole in the oil of M. aquatica.

The growing use of herbal medicines worldwide requires ensuring their quality, safety, and efficiency to consumers and patients. Quality controls of vegetal extracts are usually undertaken according to pharmacopeial monographs. Analyses may range from simple chemical experiments to more sophisticated but more accurate methods. Nowadays, metabolomic analyses allow a fast characterization of complex mixtures. In the field, besides mass spectrometry (MS), nuclear magnetic resonance spectroscopy (NMR) has gained importance in the direct identification of natural products in complex herbal extracts. For a decade, automated dereplication processes based on13 C-NMR have been emerging to efficiently identify known major compounds in mixtures. Though less sensitive than MS,13 C-NMR has the advantage of being appropriate to discriminate stereoisomers. Since NMR spectrometers nowadays provide useful datasets in a reasonable time frame, we have recently made available MixONat, a software that processes13 C as well as distortionless enhancement by polarization transfer (DEPT)-135 and -90 data, allowing carbon multiplicity (i.e., CH3 , CH2 , CH, and C) filtering as a critical step. MixONat requires experimental or predicted chemical shifts (δ C) databases and displays interactive results that can be refined based on the userʼs phytochemical knowledge. The present article provides step-by-step instructions to use MixONat starting from database creation with freely available and/or marketed δ C datasets. Then, for training purposes, the reader is led through a 30 – 60 min procedure consisting of the13 C-NMR based dereplication of a peppermint essential oil. [ABSTRACT FROM AUTHOR]

The growing use of herbal medicines worldwide requires ensuring their quality, safety, and efficiency to consumers and patients. Quality controls of vegetal extracts are usually undertaken according to pharmacopeial monographs. Analyses may range from simple chemical experiments to more sophisticated but more accurate methods. Nowadays, metabolomic analyses allow a fast characterization of complex mixtures. In the field, besides mass spectrometry (MS), nuclear magnetic resonance spectroscopy (NMR) has gained importance in the direct identification of natural products in complex herbal extracts. For a decade, automated dereplication processes based on13 C-NMR have been emerging to efficiently identify known major compounds in mixtures. Though less sensitive than MS,13 C-NMR has the advantage of being appropriate to discriminate stereoisomers. Since NMR spectrometers nowadays provide useful datasets in a reasonable time frame, we have recently made available MixONat, a software that processes13 C as well as distortionless enhancement by polarization transfer (DEPT)-135 and -90 data, allowing carbon multiplicity (i.e., CH3 , CH2 , CH, and C) filtering as a critical step. MixONat requires experimental or predicted chemical shifts (δ C) databases and displays interactive results that can be refined based on the userʼs phytochemical knowledge. The present article provides step-by-step instructions to use MixONat starting from database creation with freely available and/or marketed δ C datasets. Then, for training purposes, the reader is led through a 30 – 60 min procedure consisting of the13 C-NMR based dereplication of a peppermint essential oil. [ABSTRACT FROM AUTHOR]

To fight the rising resistance of microorganisms to antibiotics, a strategy followed by several researchers is to focus on natural compounds, such as essential oils, as a source of potent antibacterial compounds. These last decades, hundreds of original papers have been written about microbiological assays that prove the antibacterial activity of essential oils and their use in the medical field. But can we really compare all the data available in the literature when the raw material, the microbiological assays, and/or the strains are different from one article to another? This review will point out the differences and the inadequate practices found in published articles that tested 2 lesser-studied essential oils–Spanish lavender and the ajowan–by the broth dilution method against Staphylococcus aureus , a human pathogenic bacterium. Many pitfalls were found in the literature, for example, a variable chemical composition rarely underlined by the authors, unidentified strains or clinical strains used without a related antibiogram, a lack of quality controls, and the assertion of questionable positive results. At last, some general guidelines that should be followed by every scientific researcher will be discussed. [ABSTRACT FROM AUTHOR]

Plant volatile organic compounds (volatiles) are secondary plant metabolites that play crucial roles in the reproduction, defence, and interactions with other vegetation. They have been shown to exhibit a broad range of biological properties and have been investigated for antimicrobial and anticancer activities. In addition, they are thought be more environmentally friendly than many other synthetic chemicals 1. Despite these facts, their applications in the medical, food, and agricultural fields are considerably restricted due to their volatilities, instabilities, and aqueous insolubilities. Nanoparticle encapsulation of plant volatile organic compounds is regarded as one of the best strategies that could lead to the enhancement of the bioavailability and biological activity of the volatile compounds by overcoming their physical limitations and promoting their controlled release and cellular absorption. In this review, we will discuss the biosynthesis and analysis of plant volatile organic compounds, their biological activities, and limitations. Furthermore, different types of nanoparticle platforms used to encapsulate the volatiles and the biological efficacies of nanoencapsulated volatile organic compounds will be covered. [ABSTRACT FROM AUTHOR]

This review summarizes data on the in vitro antimicrobial effectiveness of volatile agents of plant origin and in vitro methods for evaluating their activity in the vapour phase. As a result of literature analysis, the antimicrobial efficacy of vapours from 122 different plant species and 19 pure compounds examined in 61 studies using different in vitro tests against a broad spectrum of microorganisms was identified and summarized. In addition, 11 different techniques found in the literature are described in detail. An original classification of methods based on the solid and liquid matrix volatilization principle is proposed because carrier medium/matrix selection is crucial for the volatilization of any agents tested. This review should be useful for medicinal, pharmaceutical, food, and agricultural experts working in areas related to the management of infectious diseases (especially respiratory and skin infections), food preservation (active packaging), and protection of agriculture products (controlled atmosphere). It may also stimulate the interest of pharmaceutical, cosmetic, food, and agriculture industries in the research and development of new antimicrobial agents of natural origin. Since several original apparatuses previously developed for antimicrobial susceptibility testing in the vapour phase are described in this review, labware manufacturers may also be interested in this topic. The review also provides specific guidelines and recommendations for researchers studying the antimicrobial activity of volatile agents. The article will therefore appeal to communities of industrial stakeholders, pharmacists, physicians, food experts, agriculturists, and researchers in related areas such as pharmacology, medicinal chemistry, microbiology, natural product chemistry, food preservation and plant protection. [ABSTRACT FROM AUTHOR]

Pediculosis is a prevalent ectoparasite infestation caused by lice. The head louse (Pediculus humanus capitis) and body louse (Pediculus humanus humanus) are obligatory parasites whose only known hosts are humans. Pediculosis is probably the most common ectoparasitic infestation, affecting up to 80% of the population in several countries, and particularly prevalent in the infant population worldwide. Several treatment options, including shampoos and creams containing insecticides, have been introduced for the treatment of pediculosis. Recently, the use of synthetic chemicals to control human lice has raised concerns pertaining to human health and the environment. Therefore, increasing efforts have been undertaken to develop effective pediculicides with low environmental toxicity and minimal environmental residual activity. In this study, we focus on the essential oils derived from 22 plant genera, their constituents, and the major factors that play important roles in the effectiveness of these oils in the treatment of pediculosis. Furthermore, we discuss the advantages and limitations of the mentioned essential oils, and ultimately suggest those demonstrating the most effective in vitro pediculicidal activities. The genera such as Aloysia, Cinnamomum, Eucalyptus, Eugenia, Lavandula, Melaleuca, Mentha, Myrcianthes, Origanum, Pimpinella , and Thymus appear to be more efficient against lice. These genera are rich in anethole, 1,8-cineole, cinnamaldehyde, p -cymene, eugenol, linalool, limonene, pulegone, terpinen-4-ol, and thymol compounds. [ABSTRACT FROM AUTHOR]

Pathogenic biofilm-associated bacteria that adhere to biological or nonbiological surfaces are a big challenge to the healthcare and food industries. Antibiotics or disinfectants often fail in an attempt to eliminate biofilms from those surfaces. Based on selected experimental research, this review deals with the potential biofilm-inhibiting, virulence factor-reducing, and biofilm-eradicating activities of essential oils and single essential oil compounds using Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa , and Chromobacterium violaceum as model organisms. In addition, for the bacteria reviewed in this overview, different essential oils and essential oil compounds were reported to be able to modulate the expression of genes that are involved in the formation of autoinducer molecules, biofilms, and virulence factors. The anti-quorum sensing activity of some essential oils and single essential oil compounds was demonstrated using the gram-negative bacterium C. violaceum. Reporter strains of this bacterium produce the violet-colored compound violacein whose synthesis is regulated by quorum sensing autoinducer molecules called acylhomeserinlactones. Of great interest was the discovery that enantiomeric monoterpenes affected the quorum sensing regulation system in different ways. While the (+)-enantiomers of carvone, limonene, and borneol increased violacein formation, their (−)-analogues inhibited violacein production. For the successful eradication of biofilms and the bacteria living inside them, it is absolutely necessary that the lipophilic volatile substances can penetrate into the aqueous channels of biofilms. As shown in recent work, hydrophilic nano-delivery systems encapsulating essential oils/essential oil compounds with antibacterial effects may contribute to overcome this problem. [ABSTRACT FROM AUTHOR]

Flowers and leaves were collected for the comparison of the trichome morphometrical data and the oil chemical data between two peppermint notomorphs ( PALLESCENS and RUBESCENS Camus). The counting of the glandular trichomes was undertaken by means of scanning electron microscope (SEM) and the averages were analyzed for variation (F-ratio). The two plants showed differences in density and number of trichomes, superior values being obtained by the M. RUBESCENS notomorph. The leaves showed a positive correlation between the number of trichomes and the oil yielded. The oil, analyzed using GC-MS coupling, showed high percentages of menthol (53.76) in the leaves and of menthol (36.65), menthone (19.71) and menthofuran (17.70) in the M. RUBESCENS flowers. The M. PALLESCENS notomorph showed high percentages of menthyl acetate (28.86) and moderate percentages of menthol (25.75) in the leaves, while in the flowers menthofuran with 21.10% gave the highest value.