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The antibacterial effect of the components of clary sage (Salvia sclarea L.) and spearmint (Mentha spicata L. var. crispa (Bentham) Danert) was investigated by means of high-performance thin-layer chromatography-direct bioautography against the Gram-positive soil bacterium Bacillus subtilis (Bs) and Gram-negative bacteria such as a pepper pathogen Xanthomonas euvesicatoria (Xe), a luminescence gene-tagged Arabidopsis pathogen Pseudomonas syringae pv. maculicola (Psm) and a luminescent marine Aliivibrio fischeri (Af). Sclareol, linalool, and linalyl acetate were identified as active components of clary sage and carvone as the antibacterial substance in spearmint. Sclareol inhibited all tested bacteria, linalool and carvone showed antibacterial effect against all Gram-negative strains tested, while linalyl acetate only against Xe and Af. Some minor components of the clary sage essential oil also gave a zone of inhibition when tested on Gram-negative bacterium strains.

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Acta Biologica Hungarica
Authors: Györgyi Horváth, Julianna Török Jenei, Csaba Vágvölgyi, Andrea Böszörményi, and Judit Krisch

Essential oils (EOs) can be used as alternative or complementary antifungal agents against human pathogenic moulds and yeasts. To reduce the effective dose of antimicrobial agents, EOs are combined which can lead to synergistic or additive effect. In this study the anti-yeast and anti-mould activities of selected EOs were investigated, alone and in combinations, against clinical isolates of Candida albicans, C. parapsilosis, Aspergillus fumigatus, A. terreus, Rhizopus microsporus, Fusarium solani and Lichtheimia corymbifera. Minimum inhibitory concentrations (MICs) were determined for the EOs of cinnamon, citronella, clove, spearmint and thyme. To investigate the combination effect of the EOs, fractional inhibitory concentrations (FICs) were defined by the checkerboard method and the type of interaction was determined by the FIC index (FICI). FIC index below 0.5 was considered as synergism and between 0.5 and 1 as additive effect. Strongest antifungal activity was showed by thyme EO with MIC values below 1.0 mg/ml. Combination of EOs resulted in additive or indifferent effect, with occasional “borderline synergism”. The best combination was cinnamon with clove leading to additive effect in all cases.

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The chemical composition of the oils of four thyme (Lamiaceae) chemotypes ( Thymus vulgaris L., Thymus serpyllum L., Thymus x citriodorus (Pers.) Schreb., and Thymus x citriodorus “Archer’s Gold”) has been determined by gas chromatography (GC). Thymol was the main component of the oils of Thymus vulgaris and Thymus serpyllum , geraniol was the main component of the oil of Thymus x citriodorus , and carvacrol was the main component of the oil of Thymus x citriodorus “Archer’s Gold”. The bioactivity of the volatile oil of Thymus vulgaris and of the three main components of the oils against Gram negative plant pathogenic bacteria was examined by direct bioautography. They had an inhibitory effect on all of the test microorganisms. Two bacterial strains ( Xanthomonas campestris pv. vesicatoria and Pseudomonas syringae pv. phaseolicola ) were most sensitive in the bioautographic system and use of these bacteria would considerably shorten the process of bioautographic detection. The two antibiotics gentamycin and streptomycin were used as controls.

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JPC - Journal of Planar Chromatography - Modern TLC
Authors: Ágnes Móricz, Györgyi Horváth, Péter Molnár, Béla Kocsis, Andrea Böszörményi, Éva Lemberkovics, and Péter Ott

The composition of the essential oil of Thymus vulgaris L. has been determined by GC-FID and GC-MS. Because separation of thymol, carvacrol, and linalool, components of the essential oil, was more efficient by overpressured layer chromatography (OPLC) than by conventional thin-layer chromatography (TLC), the forced flow technique was used before biological detection. All three test compounds had antibacterial effect against the phytopathogenic bacterium Pseudomonas syringae pv. maculicola, in bioautography, although in essential oil thymol was present in sufficient quantity to produce an inhibiting zone in the adsorbent layer. In BioArena investigations, when reduced glutathione as a formaldehyde (HCHO) capturer was dissolved in the cell suspension before bioautographic exposure to the essential oil, the characteristic inhibiting activity of thymol and carvacrol against Bacillus subtilis soil bacteria was reduced, whereas the presence of the HCHO precursors NGmonomethyl-l-arginine or N ɛ-monomethyl-l-lysine enhanced their antibacterial effect. These results suggest that HCHO and its reaction products may be involved in the antibacterial activity of thymol and carvacrol.

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The aim of the present study was the chemical characterization of some medically relevant essential oils (tea tree, clove, cinnamon bark, thyme, and eucalyptus) and the investigation of antibacterial effect of the components of these oils by use of a direct bioautographic method. Thin-layer chromatography (TLC) was combined with biological detection in this process. The chemical composition of the oils was determined by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Eucalyptol (84.2%) was the main component of the essential oil of eucalyptus, eugenol (83.7%) of clove oil, and trans-cinnamic aldehyde (73.2%), thymol (49.9%), and terpinen-4-ol (45.8%) of cinnamon bark, thyme and tea tree oils, respectively. Antibacterial activity of the separated components of these oils as well as of their pure main components (eucalyptol, eugenol, trans-cinnamic aldehyde and thymol) was observed against the Gram-negative luminescence gene-tagged plant pathogenic bacterium Pseudomonas syringae pv. maculicola (Psmlux) and the Gram-negative, naturally luminescent marine bacterium Vibrio fischeri. On the whole, the antibacterial activity of the essential oils could be related to their main components, but the minor constituents may be involved in this process. trans-Cinnamic aldehyde and eugenol were the most active compounds in TLC-bioautography. The sensitivity of TLC-bioautographic method can be improved by using luminescent test bacteria. This method is more cost-effective and provides more reliable results in comparison with conventional microbiological methods, e.g., disc-diffusion technique.

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Acta Biologica Hungarica
Authors: Zsuzsanna Pluhár, Marianna Kocsis, Anett Kuczmog, S. Csete, Hella Simkó, Szilvia Sárosi, P. Molnár, and Györgyi Horváth

Chemical and genetic differences of twenty taxa belonging to four Thymus species were studied in order to determine whether molecular characters and essential oil components could be used as taxonomic markers and to examine the correlation between them. Plant samples, representing different taxa and geographic regions, were collected from experimentally grown populations. Essential oil samples were analysed by GC/MS and cluster analysis of volatile composition resulted in segregation of thymol chemotypes from sesquiterpenic ones. Thymol was characteristic for all the populations of Thymus glabrescens and T. pannonicus as well as for certain taxa belonging to T. praecox and T. pulegioides. Sesquiterpenes occurred in only two taxa of T. glabrescens, in each sample of T. praecox and in three taxa of T. pulegioides. Plant samples were analysed by random amplified polymorphic DNA (RAPD). The obtained dendrogram revealed high gene diversity. The 13 primers resulted 114 polymorphic RAPD bands, and the average percentage of polymorphism was 80.8%. The RAPD dendogram showed separation neither at interspecific nor at interpopulational levels. Therefore, further specific molecular studies involving more taxa are suggested. Partial correlation have been found between molecular and chemical assessments.

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In this study, thin-layer chromatography—direct bioautography (TLC—DB) was used for guiding the isolation and identification of antibacterial constituents of Thymus vulgaris L. ethanol extract. This TLC—bioassay method enables the separation and detection of active components directly on the surface of chromatographic plates. They can be identified by comparison with reference substances or using physicochemical methods, preferably spectroscopic ones (liquid chromatography—tandem mass spectrometry [LC—MS/MS], in the presented paper). The described method belongs to the effect-directed analyses (EDA). Seven bacterial strains were used as test organisms, both pathogenic and nonpathogenic, including methicillin-resistant Staphylococcus aureus as well as luminescent bacteria like Aliivibrio fischeri. Five fractions with the widest antimicrobial spectra were detected using TLC—DB, isolated by semi-preparative TLC and subjected to LC—MS/MS analyses. Finally, two bioactive components were tentatively identified, basing on their fragmentation pattern, as eriodictyol and 4,4′-dihydroxy-5,5′-diisopropyl-2,2′-dimethyl-3,6-bifenylodion.

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Thin-layer chromatography—direct bioautography (TLC—DB) followed by liquid chromatography—tandem mass spectrometry (LC—MS/MS) was used for screening and tentative identification of the antibacterial constituents of Salvia officinalis L. ethanol extract. Seven bacterial strains were used as test organisms, both pathogenic and nonpathogenic, that is, Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), Staphylococcus epidermidis, Micrococcus luteus, Bacillus subtilis, luminescence gene-tagged Pseudomonas syringae pv. maculicola, and naturally luminescent marine bacterium Aliivibrio fischeri. Eight fractions with the widest antimicrobial spectrum were detected using TLC—DB, isolated by semi-preparative TLC, and subjected to LC—MS/MS analyses. Finally, five bioactive components were tentatively identified, based on their fragmentation pattern, such as salvigenin, cirsimaritin, rosmanol, carnosic acid, and 12-O-methyl carnosic acid.

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Agrokémia és Talajtan
Authors: György Heltai, Attila Anton, Sándor Hoffmann, Tibor Szili-Kovács, Katalin Berecz, Györgyi Kampfl, Krisztina Kristóf, Erik Molnár, Márk Horváth, and Ágnes Bálint

A Keszthelyen 1963-ban beállított „Szerves- és műtrágyák hatását összehasonlító tartamkísérlet” kiválasztott kezeléseiből vett talajokkal beállított tenyészedénykísérletben és ezzel párhuzamosan a szegélyparcellákból kiemelt bolygatatlan talajoszlopokban vizsgáltuk az ásványi- és istállótrágyák, valamint a talajba bedolgozott növényi szerves anyag hatását a talajlevegőben a tenyészidő folyamán felhalmozódó CO2 és N2O gázok képződésének dinamikájára.A CO2-koncentráció a tenyészidő folyamán a kezdeti stagnálás után egy, vagy több maximum elérése után a kezdeti szintre csökkent mindkét kísérleti rendszerben, s a változás jó korrelációt mutatott a napi középhőmérséklet változásával.A N2O képződésének időbeli változása a talajoszlopokban nem mutatott egyértelmű tendenciát, míg a tenyészedényekben csak a vetést követő 6. napig mértünk koncentrációnövekedést.A bolygatatlan talajoszlopokban a felszíntől 40 cm mélységig a CO2-koncentráció szignifikánsan növekedett, 40–60 cm között már nem változott számottevően. Ugyanez a tendencia mutatkozott a N2O-koncentráció mélység szerinti változásában, de a nagyobb mérési bizonytalanság miatt kevésbé egyértelműen. A tenyészedényekben a 20 cm mélyen elhelyezett csapdákban mért CO2-koncentráció értékek nagyságrendileg megegyeztek a talajoszlopban 20 cm mélyen mért értékekkel. A trágyázatlan kezelésekben a növények jelenléte mind a talajoszlopban, mind a tenyészedényekben növelte a CO2- és a N2O-produkciót. A trágyázási kezelések hatására a talajoszlopokban csökkent mindkét gáz produkciója. Szerves trágya alkalmazásakor növény jelenlétében ez a csökkenés kisebb mértékű volt, mint ásványi trágya esetében. A trágyázási kezelések hatására a tenyészedényekben növények jelenlétében növekedett a talajban a CO2 és N2O produkciója. A növekedés a trágyakezelések termésnövelő hatása sorrendjében istállótrágya < ásványi trágya < (istállótrágya+ásványi trágya) fokozódott.Összegezve megállapítható, hogy a CO2 és N2O gázképződés és a talajból történő kilépés feltételei a bolygatatlan és a művelt talajban eltérnek, s e folyamatra jelentős hatással van a növények jelenléte és anyagcseréje. Kísérleteink eredményeként létrehoztunk egy olyan adatbázist, amelyre alapozva megfelelő matematikai modellek alkalmazásával reálisan becsülhető a mezőgazdasági talajok CO2 és N2O emissziója különböző tápanyagellátási és művelési módok esetén.

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Meibom-mirigy-diszfunkció és a száraz szem

Diagnosztikai és kezelési lehetőségek

Meibomian gland dysfunction and dry eye

Diagnosis and treatment
Orvosi Hetilap
Authors: Balázs Kovács, Boglárka Láng, Anna Takácsi-Nagy, Györgyi Horváth, Cecília Czakó, Anita Csorba, Huba Kiss, Irén Szalai, Zoltán Zsolt Nagy, and Illés Kovács

Összefoglaló. A szárazszem-panaszok hátterében gyakran áll Meibom-mirigy-diszfunkció, melynek felismerése kiemelten fontos a hatékony kezelés érdekében. A Meibom-mirigyek kóros működése miatt a termelt lipid nem oszlik el megfelelően a szemfelszínen, így a könnyfilm párolgása fokozódik. A könnytermelési zavar következtében szárazszem-panaszok alakulnak ki, melyek a hagyományos könnypótló kezelésre rendszerint csak átmenetileg javulnak. A Meibom-mirigy-diszfunkciót gyakran kíséri a szemhéjszél Demodex-atka-fertőzése – az atka eradikálása szükséges a mirigyek működésének helyreállításához és ezáltal a panaszok megszüntetéséhez. A Meibom-mirigy-diszfunkció a leggyakrabban enyhe formában jelentkezik; a terápia ilyenkor a beteg által is elvégezhető szemhéjtisztításból áll, míg a gyógyszeres kezelés csak az előrehaladottabb, kifejezett gyulladással járó formákban szükséges. Az összefoglaló áttekinti a Meibom-mirigy-diszfunkció klinikai jeleivel és kezelésével kapcsolatos legfontosabb tudnivalókat, különös tekintettel a Demodex-fertőzés felismerésére és kezelésére vonatkozóan. Orv Hetil. 2021; 162(2): 43–51.

Summary. The onset of dry eye complaints is often a result of Meibomian gland dysfunction and its diagnosis is essential for effective treatment. In the case of Meibomian gland dysfunction, there is an increased evaporation of the tear film due to the abnormal secretion of lipids that cannot spread on the ocular surface. The treatment of dry eye complaints associated with Meibomian gland dysfunction with tear supplementation is usually ineffective and only results in an intermittent relief of complaints. Meibomian gland dysfunction is often associated with Demodex infestation of the eyelids, and eradicating the mites is essential to re-establish normal meibum production and thus, decreasing ocular complaints. In most cases, Meibomian gland dysfunction is mild, and the treatment of these forms is based on ocular hygiene performed by the patient, while only more advanced forms with inflammatory processes require pharmacologic treatment. This review summarizes the most important knowledge on the clinical signs and treatment of Meibomian gland dysfunction with particular attention to the diagnosis and treatment of ocular Demodex infection. Orv Hetil. 2021; 162(2): 43–51.

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