Binary mixture of Satureja hortensis and Origanum vulgare subsp. hirtum essential oils: in vivo therapeutic efficiency against Helicobacter pylori infection.

BACKGROUND: Helicobacter pylori can cause many gastrointestinal and also extra-gastrointestinal disorders and is a major risk factor for gastric carcinoma and MALT lymphoma. Currently, numerous antibiotic-based therapies are available; however, these therapies have numerous drawbacks, mainly due to increasing prevalence of antibiotic resistant strains. Thus, there is an urgent need to develop novel therapeutic agents against H. pylori infections. MATERIALS AND METHODS: In this study, the anti-H. pylori activity of 2:1 mixture of Satureja hortensis and Origanum vulgare subsp. hirtum essential oils (2MIX) was investigated in vivo. After screening in vitro cytotoxicity of 2MIX on mammalian cell lines, the therapeutic efficiency was studied in a mouse model, where changes in H. pylori colonization were detected by PCR and histology of gastric samples. The immune reaction of mice was tested based on cytokine and chemokine production, and the in vivo toxicity of 2MIX was also investigated by measuring ALT and AST enzyme activities and Cyp3a11 and HO-1 mRNA levels in livers of mice. RESULTS: 2MIX had not shown in vitro cytotoxicity against cell lines, only the highest concentration caused significant decrease in their survival rates. In the in vivo experiments, 2MIX successfully eradicated the pathogen in 70% of the mice. We could not detect toxicity or altered cytokine and chemokine balance after in vivo treatments in mice. CONCLUSIONS: These results show that 2MIX is effective in reducing H. pylori colonization suggesting that this essential oil mixture has great potential as a new, effective, and safe therapeutic agent against H. pylori.

Chemical Composition and Immuno-Modulatory Effects of Urtica dioica L. (Stinging Nettle) Extracts.

The purpose of this work was to determine the chemical profile of stinging nettle and to provide an insight into the mechanisms by which it ameliorates the immune response. Qualitative and quantitative liquid chromatography tandem mass spectrometry analyses indicated that phenolic acids (5-O-caffeoylquinic acid as dominant) and flavonol glycosides (rutin, isoquercitrin, and kaempferol 3-O-glucoside) are present in the aerial parts, while lignans (secoisolariciresinol, 9,9'-bisacetyl-neo-olivil and their glucosides) were detected in the root. Herb and root extracts expressed selective inhibition toward cyclooxygenase and lipoxygenase branches in human platelets: root extracts were better at inhibiting thromboxane production, while herb extracts were more specific toward inhibition of 12-lipoxygenase pathway. Stinging nettle extracts mildly increased monocyte chemoattractant protein-1 and growth-related oncogene release from nonstimulated intestinal epithelial cells, stimulating MyD88/NF-κB/p38 signaling, hence preserving the epithelial integrity and enhancing intestinal steady-state defense. Additionally, root extract reduced lipopolysaccharide-induced monocyte chemoattractant protein-1/growth-related oncogene secretion and cyclooxygenase-2 expression in intestinal epithelial cells, thus showing the potential protective effect against tissue damage caused by inflammation processes. These observations suggest that stinging nettle is an interesting candidate for the development of phytopharmaceuticals or dietary supplements for cotreatment of various inflammatory diseases, particularly inflammatory bowel diseases. Copyright © 2017 John Wiley & Sons, Ltd.

Binary and Tertiary Mixtures of Satureja hortensis and Origanum vulgare Essential Oils as Potent Antimicrobial Agents Against Helicobacter pylori.

Essential oils possess strong antimicrobial activity, even against multiresistant Helicobacter pylori. Available therapies against H. pylori infection have multiple disadvantages, indicating a great need for a development of new therapeutics. The purpose of this study was to develop a potent natural product based anti-H. pylori formulation. First, anti-H. pylori activity of nine essential oils was determined, after which the most active oils were mixed in various ratios for further testing. Satureja hortensis, Origanum vulgare subsp. vulgare and O. vulgare subsp. hirtum essential oils expressed the highest activity (MIC = 2 µL mL(-1)). Their binary and ternary mixtures exhibited notably higher antimicrobial activity (MIC ≤ 2 µL mL(-1)). The most active was the mixture of S. hortensis and O. vulgare subsp. hirtum oils in volume ratio 2:1, which expressed 4 times higher activity than individual oils (MIC = 0.5 µL mL(-1)). According to GC-MS, both oils in the mixture were characterized by high content of phenols (48-73%), with carvacrol as the main carrier of antimicrobial activity. Presented in vitro study pointed out binary mixture of S. hortensis and O. vulgare subsp. hirtum essential oils in volume ratio 2:1 as promising candidate for further in vivo studies targeting H. pylori infection.

Effect of Allium flavum L. and Allium melanantherum Panc. Extracts on Oxidative DNA Damage and Antioxidative Enzymes Superoxide Dismutase and Catalase.

Allium flavum L. and Allium melanantherum Panc. are wild growing plants used in traditional diet in Balkan region. While chemical composition and some biological activities of A. flavum have been reported, A. melanantherum, as an endemic in the Balkan Peninsula, has never been comprehensively examined. After chemical characterization of A. melanantherum, we examined the protective effect of methanol extracts of both species against t-butyl hydro-peroxide (t-BOOH)-induced DNA damage and mutagenesis. The bacterial reverse mutation assay was performed on Escherichia coli WP2 oxyR strain. DNA damage was monitored in human fetal lung fibroblasts (MRC-5) with alkaline comet assay. Obtained results indicated that extracts reduced t-BOOH-induced DNA damage up to 70 and 72% for A. flavum and A. melanantherum extract, respectively, and showed no effect on t-BOOH-induced mutagenesis. Since the results indicated modulatory effect on cell-mediated antioxidative defense, the effect of extracts on total protein content, and superoxide dismutase (SOD) and catalase (CAT) amounts and activities were monitored. Both extracts increased total protein content, while the increase of enzyme amount and activity was obtained only with A. melanantherum extract and restricted to CAT. The activity of CuZnSOD family was not affected, while SOD1 and SOD2 amounts were significantly decreased, indicating potential involvement of extracellular CuZnSOD. Obtained results strongly support the traditional use of A. flavum and A. melanantherum in nutrition and recommend them for further study.

Beyond Mortality: Exploring the Influence of Plant Phenolics on Modulating Ferroptosis-A Systematic Review.

Ferroptosis is a recently discovered type of programmed cell death that is mechanistically different from other types of programmed cell death such as apoptosis, necroptosis, and autophagy. It is characterized by the accumulation of intracellular iron, overproduction of reactive oxygen species, depletion of glutathione, and extensive lipid peroxidation of lipids in the cell membrane. It was discovered that ferroptosis is interconnected with many diseases, such as neurodegenerative diseases, ischemia/reperfusion injury, cancer, and chronic kidney disease. Polyphenols, plant secondary metabolites known for many bioactivities, are being extensively researched in the context of their influence on ferroptosis which resulted in a great number of publications showing the need for a systematic review. In this review, an extensive literature search was performed. Databases (Scopus, Web of Science, PubMed, ScienceDirect, Springer) were searched in the time span from 2017 to November 2023, using the keyword "ferroptosis" alone and in combination with "flavonoid", "phenolic acid", "stilbene", "coumarin", "anthraquinone", and "chalcone"; after the selection of studies, we had 311 papers and 143 phenolic compounds. In total, 53 compounds showed the ability to induce ferroptosis, and 110 compounds were able to inhibit ferroptosis, and out of those compounds, 20 showed both abilities depending on the model system. The most researched compounds are shikonin, curcumin, quercetin, resveratrol, and baicalin. The most common modes of action are in the modulation of the Nrf2/GPX4 and Nrf2/HO-1 axis and the modulation of iron metabolism.

New Garden Rose (Rosa × hybrida) Genotypes with Intensely Colored Flowers as Rich Sources of Bioactive Compounds.

Garden roses, known as Rosa × hybrida, hold a prominent position as one of the most important and economically valuable plants in horticulture. Additionally, their products-essential oil, rose water, concrete, and concentrate-find extensive use in the cosmetic, pharmaceutical, and food industries, due to their specific fragrances and potential health benefits. Rose flowers are rich in biologically active compounds, such as phenolics, flavonoids, anthocyanins, and carotenoids. This study aims to investigate the potential of five new garden rose genotypes with intensely colored flowers to serve as sources of biologically active compounds. Phenolic profile was evaluated by determination of total phenolic (TPC), flavonoid (TFC), and monomeric anthocyanins (TAC) contents and LC-MS/MS analysis of selected compounds. Antioxidant activity was evaluated via DPPH and FRAP assays, neuroprotective potential via acethylcholinesterase inhibition assay, and antidiabetic activity viaα-amylase and α-glucosidase inhibition assays. The flowers of investigated genotypes were rich in phenolics (TPC varied from 148 to 260 mg galic acid eq/g de, TFC from 19.9 to 59.7 mg quercetin eq/g de, and TAC from 2.21 to 13.1 mg cyanidin 3-O-glucoside eq/g de). Four out of five genotypes had higher TPC than extract of R. damascene, the most famous rose cultivar. The dominant flavonoids in all investigated genotypes were glycosides of quercetin and kaempferol. The extracts showed high antioxidant activity comparable to synthetic antioxidant BHT, very high α-glucosidase inhibitory potential, moderate neuroprotective activity, and low potential to inhibit α-amylase.

Recovery of Polyphenols from Rosehip Seed Waste Using Natural Deep Eutectic Solvents and Ultrasonic Waves Simultaneously.

Rosehips are processed and consumed in numerous forms, such as juice, wine, herbal tea, yogurt, preserved fruit, and canned products. The seeds share in fruit is 30-35% and they have recently been recognized as an important source of oil rich in unsaturated fatty acids. However, after defatting, seed waste may still contain some polar polyphenolic compounds, which have been scarcely investigated. The aim of this study was to examine the potential of the defatted seed waste as a source of polyphenols. For the defatting process, supercritical carbon dioxide extraction at 300 bar and 40 °C was applied. The capacity of eight different natural deep eutectic solvents (NADES) for the recovery of phenolics from defatted rosehip seed powder (dRSP) was examined. In the extracts obtained with ultrasound-assisted NADES extraction, twenty-one phenolic compounds were identified with LC-MS/MS, among which the most abundant were quinic acid (22.43 × 103 µg/g dRSP) and catechin (571.93 µg/g dRSP). Ternary NADES formulations based on lactic acid proved to be superior. Potential correlations between identified chemical compounds, solvent polarity and viscosity, as well as the compound distributions across studied solvent combinations in PCA hyperspace, were also investigated. PCA demonstrated that more polar NADES mixtures showed improved extraction potential. The established environmentally friendly process represents an approach of transforming rosehip seed waste into value-added products with the potential to be applied in the food industry and to contribute to sustainable production.

Invitro and in vivo anthelmintic efficacy of peppermint (Mentha x piperita L.) essential oil against gastrointestinal nematodes of sheep.

Nowadays, the exclusive use of commercial anthelmintics for the treatment of gastrointestinal nematode infections in ruminants is less sustainable due to anthelmintic resistance, as well as the problem of drug residues in animal products and the environment. Therefore, an integrated therapeutic approach is needed, including the search for alternatives to synthetic anthelmintic drugs. The aim of this study was to evaluate the possibility of using the essential oil of peppermint (Mentha x piperita L.) in the control of gastrointestinal nematodes in sheep. For this purpose, the in vitro and in vivo anthelmintic efficacy of this oil and the toxic effects on the hosts were examined. In the in vitro egg hatch test, ovicidal activity varied from 21.0-90.3% depending on the concentration of essential oil used (0.0125, 0.025, 0.049, 0.195, 0.781, 3.125, 12.5, and 50 mg/mL). To some extent, anthelmintic efficacy was confirmed in the in vivo fecal egg count reduction test at a mean dose of 150 mg/kg, with an average reduction of nematode eggs of 26.9 and 46.0% at Days 7 and 14 after treatment, respectively. Furthermore, no toxic effects of applied oil were observed on sheep behavior, kidney, or liver function. The main compounds identified by gas chromatography-mass spectrometry analyzes were menthol (32.6%), menthone (22.0%), menthyl-acetate (10.0%), and isomenthone (9.39%). Due to their complex chemical compositions, numerous bioactive ingredients, and natural origin, herbal formulations represent a potentially valuable alternative for the control of gastrointestinal nematodes in sheep. In this context, the results of the present study showed that peppermint essential oil is one of the promising candidates. Further studies should be performed to collect more data on the safety profile of M. piperita EO in treated animals to find the most appropriate formulation for use in field conditions and to test it against resistant gastrointestinal nematode populations.

Can Polyphenols Inhibit Ferroptosis?

Polyphenols, a diverse group of naturally occurring molecules commonly found in higher plants, have been heavily investigated over the last two decades due to their potent biological activities-among which the most important are their antioxidant, antimicrobial, anticancer, anti-inflammatory and neuroprotective activities. A common route of polyphenol intake in humans is through the diet. Since they are subjected to excessive metabolism in vivo it has been questioned whether their much-proven in vitro bioactivity could be translated to in vivo systems. Ferroptosis is a newly introduced, iron-dependent, regulated mode of oxidative cell death, characterized by increased lipid peroxidation and the accumulation of toxic lipid peroxides, which are considered to be toxic reactive oxygen species. There is a growing body of evidence that ferroptosis is involved in the development of almost all chronic diseases. Thus, ferroptosis is considered a new therapeutic target for offsetting many diseases, and researchers are putting great expectations on this field of research and medicine. The aim of this review is to critically analyse the potential of polyphenols to modulate ferroptosis and whether they can be considered promising compounds for the alleviation of chronic conditions.

Anthelmintic Properties of Essential Oils to Control Gastrointestinal Nematodes in Sheep-In Vitro and In Vivo Studies.

Herbal products such as essential oils may play a promising role in the treatment of infections caused by gastrointestinal nematodes (GINs). The aim of this study was to evaluate the in vitro potential of 11 essential oils (EOs) and one binary combination of isolated EO compounds, as well as the in vivo anthelmintic efficacy of two EO formulations. Four GIN genera were identified in the coproculture examination: Haemonchus, Trichostrongylus, Teladorsagia and Chabertia. The in vitro egg hatch test (EHT) was performed at six different concentrations (50, 12.5, 3.125, 0.781, 0.195 and 0.049 mg/mL) for each EO, whereas in the in vivo faecal egg count reduction test (FECRT), each EO sample was diluted in sunflower oil and orally administrated at a dose of 100 mg/kg to the different group of animals. In the EHT, the EOs of Origanum vulgare, Foeniculum vulgare, Satureja montana, Satureja hortensis and two types of Thymus vulgaris were the most effective. The dominant compounds of these EOs were carvacrol, thymol, anethol, p-cymene and γ-terpinene, indicating their importance for the anthelmintic activity. In the FECRT, both T. vulgaris EO type 1 and linalool:estragole combination show an anthelmintic potential with a mean effect on FECR of approximately 25%. The results suggest the possible role of tested EOs as anthelmintic agents in sheep farms, although further in vivo tests are needed.

A Potential Anthelmintic Phytopharmacological Source of Origanum vulgare (L.) Essential Oil against Gastrointestinal Nematodes of Sheep.

The development of anthelmintic resistance in sheep gastrointestinal nematodes (GINs) requires novel strategies for the sustainable control of these parasites. This study aimed to evaluate the anthelmintic efficacy of the Origanum vulgare (L.) essential oil (EO) against sheep GINs and to evaluate the possibility of its use in control practice. The in vitro egg hatch test was conducted at eight different concentrations (50, 12.5, 3.125, 0.781, 0.195, 0.049, 0.025, and 0.0125 mg/mL) of the tested EO. For the in vivo fecal egg count reduction test, the EO of O. vulgare was administrated orally at a mean single dose of 150 mg/kg to sheep from two farms in Southern Italy, whereby potential toxic effects to the hosts were also evaluated. In the egg hatch test, the inhibition of egg hatchability varied from 71.3% to 93.7%, depending on the concentration used. The high anthelmintic potential was confirmed in the fecal egg count reduction test with an average reduction of nematode eggs in feces of 43.2% and 60.1% on days 7 and 14 after treatment, respectively. In addition, no toxic effects were noticed during the clinical examination of sheep or by observing blood count and liver or kidney function test results. The obtained results suggest the strong activity of the O. vulgare EO against sheep GINs, probably due to a high percentage of carvacrol (76.21%), whereby it can be considered safe for sheep at the dose tested in vivo. Therefore, it is suitable for use in veterinary practice as a part of an integrated strategy for the control of sheep GINs.

Roots of Apium graveolens and Petroselinum crispum-Insight into Phenolic Status against Toxicity Level of Trace Elements.

Celery (Appium graveolens L.) and parsley (Petroselinum crispum (Mill.) Fuss) are herbs utilized in the everyday diet as spices and culinary flavorings, often used in the chemical and medicinal industries. Despite the knowing benefits of different plants from the Apiaceae family, their chemical composition is closely associated with various extrinsic factors. Environmental loading with trace elements (TEs) can modify a plant's metabolic pathways, change bioactive compounds production, cause plant pollution, and consequently provoke human health issues. Therefore, we established this research aiming to unravel the linkage between TEs accumulation and phenolic status in celery and parsley. Higher As, Cd, and Ni levels were observed in celery, which was followed by greater DPPH∙ radical scavenging activity and higher coumarins content. Contrary, parsley accumulated chromium to a greater extent, was richer in flavonoids, apigenin, and its glucosides. No significant difference between species was found in total phenolic contents, where ferulic and chlorogenic acid dominated in both species. A direct relationship between TEs and selected secondary metabolites was proven by the standardized major axis model. Besides abundant bioactive compounds, analyzed plant species showed a moderate hazard index in the children population, since the hazard index was higher than 1. Therefore, future perspectives should be turned towards the production of genotypes with a lower potential for toxic elements accumulation, so the health benefits of plant food will be more prominent.

The antiinflammatory, gastroprotective and antioxidant activities of Hieracium gymnocephalum extract.

The present study investigated the antiinflammatory, gastroprotective and antioxidant activities of a CH(2)Cl(2) extract of western Balkan endemic Hieracium gymnocephalum Griseb. ex Pant. (Compositae). The carrageenan-induced rat paw oedema test was used as an experimental model for screening the antiinflammatory activity. The extract was administrated p.o. in doses of 25, 50, 100 and 200 mg/kg to rats and its effects compared with indomethacin, used p.o. as a reference drug. The results showed that the investigated extract reduced the oedema in a concentration-dependent manner. The obtained antiinflammatory effect was 5.9%, 11.7%, 31.2% and 44.1% at doses of 25, 50, 100 and 200 mg/kg, respectively, being statistically significant at a dose of 100 mg/kg. Indomethacin had a strong antiinflammatory effect of 73.4% at a dose of 8 mg/kg, but caused large gastric lesions. When the plant extract in the highest tested dose (200 mg/kg) was concomitantly given with indomethacin, the antiinflammatory effect was slightly enhanced, but the gastric lesions were significantly reduced. The antioxidant activity of the H. gymnocephalum extract, investigated using DPPH radical assay, OH-radical assay and TBA-test, was not substantial.

Phenolic compounds in field horsetail (Equisetum arvense L.) as natural antioxidants.

In this paper, the study of antioxidant activity and phenolic composition of three different extracts (EtOAc, n-BuOH and H(2)O) of field horsetail (Equisetum arvense L.) is presented. The antioxidant activity has been evaluated measuring the total reducing power (expressed by Ascorbate Equivalent Antioxidant Capacity - AEAC), inhibition of lipid peroxidation, and free radical scavenging capacity (RSC) towards 2,2-diphenyl-1-picrylhydrazyl (DPPH radical) and nitric oxide (NO), respectively. In addition, the total flavonoid content (TFC) and phenolic constituents of each extract have been determined. The results obtained show that the highest RSC regarding both DPPH and NO radicals is expressed by EtOAc extract (EC(50)=2.37 microg/mL and EC(50)=90.07 microg/mL, respectively), and the lowest by H(2)O extract (EC(50)=37.2 microg/mL and EC(50)>333.33 microg/mL, respectively). n-BuOH extract showed the highest total reducing power (AEAC=13.40 microg/mL). Differences in the phenolic composition of examined extracts are found comparing the HPLC chemical profiles. Although, isoquercitrin is the main flavonoid in both EtOAc and n-BuOH extracts, a considerable amount of di-E-caffeoyl-meso-tartaric acid was presented in the n-BuOH extract. In H(2)O extract high content of phenolic acids and low percentage of flavonoids were detected.

Chemical composition, antioxidant and antibacterial properties of Achillea collina Becker ex Heimerl s.l. and A. pannonica Scheele essential oils.

The in vitro antioxidant and antimicrobial activities of two Achillea millefolium (Adanson) Koch s.l species essential oils (A. collina Becker ex Heimerl s.l. and A. pannonica Scheele, Asteraceae) originating from the Golija and Radan mountains (Serbia) were investigated. The chemical profiles of the essential oils were evaluated by GC-MS. Antioxidant activity was assessed as free radical scavenging capacity (RSC) towards 2,2-diphenyl-1-picrylhydrazil (DPPH) radicals, together with effects on lipid peroxidation (LP). Antibacterial activity was examined on 21 bacterial strains. Based on the chemical composition of the essential oil, A. collina s.l. from Mount Golija was classified as a chamazulene chemotype (tetraploid). The high percentage of oxygenated monoterpenes and absence of azulene in the essential oil obtained from A. pannonica from Radan pointing that this population is octaploid. Essential oil of A. pannonica expressed stronger antimicrobial activity on almost all tested bacteria. Furthermore, this essential oil expressed higher scavenging effects on DPPH radical (IC(50) = 0.52 comparing to 0.62 mug/mL). Only in the LP evaluation, essential oil of A. collina s.l. from Golija exhibited stronger antioxidant activity (IC(50) = 0.75 comparing to 2.12 mug/mL).

A colorimetric broth microdilution method for assessment of Helicobacter pylori sensitivity to antimicrobial agents.

Helicobacter pylori is a major infective etiological agent of the upper gastrointestinal tract diseases. The bacterium exhibits resistance to various conventional antibiotics, being usually challenging for eradication. Since there is an urge to consider alternative therapeutic strategies, the aim of the study was to examine selected essential oils of plants belonging to families Cupressaceae (Juniperus communis) and Lamiaceae (Hyssopus officinalis, Salvia officinalis, Melissa officinalis, Lavandula angustifolia, Ocimum basilicum and Thymus serpyllum) against H. pylori, using an improved microdilution broth method. The oils were examined in concentration range from 0.03 to 4 µL/mL. The method comprises Brain-heart infusion broth supplemented with yeast extract, horse serum and IsoVitaleX. After 3 day incubation, an equal volume of double strengthen Christensen's urea was added into each well and incubated for additional 4 h. In wells with present H. pylori, the medium changed color from yellow to purple, allowing MIC determination even without a microtitre plate reader. The microtitre format method is convenient as it is less expensive, easier to perform and requires less amount of an anti-H. pylori agent. The improved method enhances specificity to H. pylori, as fast urease activity is almost an exclusive property of this bacterium. The application of the second step incubation with Christensen's urea decreases the possibility of false positive/negative results due to contaminant growth or commonly poor H. pylori growth. Among the examined oils, J. communis, H. officinalis and O. basilicum were not active with the highest applied concentrations, while the most active was T. serpyllum, with MIC 2.0-4.0 µL/mL. This is the first report on essential oils activity of T. serpyllum and H. officinalis against H. pylori.

Characterization of the volatile composition of essential oils of some lamiaceae spices and the antimicrobial and antioxidant activities of the entire oils.

The essential oils of Ocimum basilicum L., Origanum vulgare L., and Thymus vulgaris L. were analyzed by means of gas chromatography-mass spectrometry and assayed for their antioxidant and antimicrobial activities. The antioxidant activity was evaluated as a free radical scavenging capacity (RSC), together with effects on lipid peroxidation (LP). RSC was assessed measuring the scavenging activity of the essential oils on 2,2-diphenyl-1-picrylhydrazil (DPPH(*)) and OH(*) radicals. Effects on LP were evaluated following the activities of essential oils in Fe(2+)/ascorbate and Fe(2+)/H(2)O(2) systems of induction. Essential oils exhibited very strong RSCs, reducing the DPPH radical formation (IC(50)) in the range from 0.17 (oregano) to 0.39 microg/mL (basil). The essential oil of T. vulgaris exhibited the highest OH radical scavenging activity, although none of the examined essential oils reached 50% of neutralization (IC(50)). All of the tested essential oils strongly inhibited LP, induced either by Fe(2+)/ascorbate or by Fe(2+)/H(2)O(2). The antimicrobial activity was tested against 13 bacterial strains and six fungi. The most effective antibacterial activity was expressed by the essential oil of oregano, even on multiresistant strains of Pseudomonas aeruginosa and Escherichia coli. A significant rate of antifungal activity of all of the examined essential oils was also exhibited.

Antimicrobial activity of Eucalyptus camaldulensis essential oils and their interactions with conventional antimicrobial agents against multi-drug resistant Acinetobacter baumannii.

ETHNOPHARMACOLOGICAL RELEVANCE: Traditional herbal medicine has become an important issue on the global scale during the past decade. Among drugs of natural origin, special place belongs to essential oils, known as strong antimicrobial agents that can be used to combat antibiotic-resistant bacteria. Eucalyptus camaldulensis leaves are traditional herbal remedy used for various purposes, including treatment of infections. The aim of this study was to determine antimicrobial potential of two E. camaldulensis essential oils against multi-drug resistant (MDR) Acinetobacter baumannii wound isolates and to examine possible interactions of essential oils with conventional antimicrobial agents. MATERIALS AND METHODS: Chemical composition of essential oils was determined by gas chromatography-mass spectrometry analysis (GC-MS). MIC values of essential oils against A. baumannii strains were estimated by modified broth microdilution method. The components responsible for antimicrobial activity were detected by bioautographic analysis. The potential synergy between the essential oils and antibiotics (ciprofloxacin, gentamicin and polymyxin B) was examined by checkerboard method and time kill curve. RESULTS: The dominant components of both essential oils were spatulenol, cryptone, p-cimene, 1,8-cineole, terpinen-4-ol and ß-pinene. The detected MICs for the E. camaldulensis essential oils were in range from 0.5 to 2 µl mL(-1). The bioautographic assay confirmed antibacterial activity of polar terpene compounds. In combination with conventional antibiotics (ciprofloxacin, gentamicin and polymyxin B), the examined essential oils showed synergistic antibacterial effect in most of the cases, while in some even re-sensitized MDR A. baumannii strains. The synergistic interaction was confirmed by time-kill curves for E. camaldulensis essential oil and polymyxin B combination which reduced bacterial count under detection limit very fast, i.e. after 6h of incubation. CONCLUSIONS: The detected anti-A. baumannii activity of E. camaldulensis essential oils justifies traditional use of this plant. The proven E. camaldulensis essential oil synergistic interactions with conventional antibiotics could lead to the development of new treatment strategies of infections caused by MDR A. baumannii strains in the term of antibiotic dose reduction.

Antimicrobial and antioxidant activities of Melissa officinalis L. (Lamiaceae) essential oil.

The present study describes antimicrobial and free radical scavenging capacity (RSC) together with the effects on lipid peroxidation (LP) of Melissa officinalis essential oil. The chemical profile of essential oil was evaluated by the means of gas chromatography-mass spectrometry (GC-MS) and thin-layer chromatography (TLC). RSC was assessed measuring the scavenging activity of essential oil on the 2,2-diphenyl-1-picrylhydrazyl (DPPH(*)) and OH(*) radicals. The effect on LP was evaluated following the activities on Fe(2+)/ascorbate and Fe(2+)/H(2)O(2) systems of induction. The antimicrobial activity was tested against 13 bacterial strains and six fungi. The examined essential oil exhibited very strong RSC, reducing the DPPH radical formation (IC(50) = 7.58 microg/mL) and OH radical generation (IC(50) = 1.74 microg/mL) in a dose-dependent manner. According to the GC-MS and TLC (dot-blot techniques), the most powerful scavenging compounds were monoterpene aldehydes and ketones (neral/geranial, citronellal, isomenthone, and menthone) and mono- and sesquiterpene hydrocarbons (E-caryophyllene). Very strong inhibition of LP, particularly in the Fe(2+)/H(2)O(2) system of induction (94.59% for 2.13 microg/mL), was observed in both cases, also in a dose-dependent manner. The most effective antibacterial activity was expressed on a multiresistant strain of Shigella sonei. A significant rate of antifungal activity was exhibited on Trichophyton species.

Erythropoietin in amniotic fluid as a potential marker in distinction between growth restricted and constitutionally small fetuses.

OBJECTIVE: To determine if there is any difference in amniotic fluid erythropoietin (EPO) concentration between fetuses small for gestational age (SGA) and appropriate for gestational age (AGA), and between the constitutionally small (CSF) and growth-restricted (GRF) fetuses. METHODS: EPO concentrations in the amniotic fluid samples were determined by EpoELISA test in 38 pregnancies with SGA and 15 pregnancies with AGA fetuses. In the SGA group we measured Ponderal index (PI) and skin-fold thickness (SFT). If PI and/or SFT were below 10th percentile the neonate was GRF. If both PI and SFT were above 10th percentile the neonate was CSF. RESULTS: Higher levels of EPO were detected in the SGA in comparison to the AGA fetuses (p < 0.01). EPO concentration was higher in GRF compared to CSF (p < 0.05). The EPO cut-off level between SGA and AGA was 6.81 IU/L (sensitivity 92.3%; specificity 73.3%), and between GRF and CSF was 9.8 IU/L (sensitivity 81%; specificity 80%). CONCLUSION: The preliminary results of this study suggest that amniotic fluid erythropoietin concentration is elevated in growth-restricted fetuses and could potentially be used for distinction between growth restricted and constitutionally small fetuses. Confirmation of these results on a larger group of pregnant women is needed.