Polyphenolic profile and in vitro biological activity of Serbian orange (skin fermented white) wines.

Orange wines are made from white grapes, but with prolonged skin contact during fermentation. Available data on their composition and potential health benefits are limited, so polyphenolic profile (HPLC analysis) and in vitro biological activities (enzyme inhibition, antioxidant, and anti-inflammatory) of 24 Serbian orange wines were analyzed, including the correlation between determined composition and bioactivities. The wines displayed distinct polyphenolic profiles, enabling partial differentiation based on overall polyphenol content, including dominant components (catechin, gallic and caffeic acids), along with occasional occurrences of anthocyanins. However, no discernible distinctions were noted based on grape varieties, vintage, or producer. All twenty-four orange wines showed a reasonable inhibition of digestive enzymes and lipid peroxidation, twenty-one samples reduced ROS generation in the cell-based assay, but only two suppressed both PGE2 and TXA2 production in U937 cells, implicating possible functional food properties. No significant correlation between polyphenolic profile and determined biological activities was noticed.

In Vitro Study of Two Edible Polygonoideae Plants: Phenolic Profile, Cytotoxicity, and Modulation of Keap1-Nrf2 Gene Expression.

Polygonum aviculare and Persicaria amphibia (subfam. Polygonoideae) are used in traditional cuisines and folk medicine in various cultures. Previous studies indicated that phytochemicals obtained from Polygonoideae plants could sensitize chemoresistant cancer cells and enhance the efficacy of some cytostatics. Here, the cytotoxic properties of chemically characterized ethanol extracts obtained from P. aviculare and P. amphibia, individually and in combination with doxorubicin (D), were determined against hepatocarcinoma HepG2 cells. Phenolic composition, cell viability, cell cycle, apoptosis, and the expression of Keap1 and Nrf2 were examined by following methods: LC-MS/MS, LC-DAD-MS, MTT, flow cytometry, and qRT-PCR. Extracts were rich in dietary polyphenolics. Synergistic cytotoxicity was detected for extracts combined with D. The observed synergisms are linked to the interference with apoptosis, cell cycle, and expression of Keap1-Nrf2 genes involved in cytoprotection. The combined approach of extracts and D could emerge as a potential pathway of chemotherapy improvement.

Anti-Virulence Potential and In Vivo Toxicity of Persicaria maculosa and Bistorta officinalis Extracts.

Many traditional remedies represent potential candidates for integration with modern medical practice, but credible data on their activities are often scarce. For the first time, the anti-virulence potential and the safety for human use of the ethanol extracts of two medicinal plants, Persicaria maculosa (PEM) and Bistorta officinalis (BIO), have been addressed. Ethanol extracts of both plants exhibited anti-virulence activity against the medically important opportunistic pathogen Pseudomonas aeruginosa. At the subinhibitory concentration of 50 µg/mL, the extracts demonstrated a maximal inhibitory effect (approx. 50%) against biofilm formation, the highest reduction of pyocyanin production (47% for PEM and 59% for BIO) and completely halted the swarming motility of P. aeruginosa. Both extracts demonstrated better anti-quorum sensing and antibiofilm activities, and a better ability to interfere with LasR receptor, than the tested dominant extracts' constituents. The bioactive concentrations of the extracts were not toxic in the zebrafish model system. This study represents an initial step towards the integration of P. maculosa and B. officinalis for use in the treatment of Pseudomonas infections.

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.

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.

Quantitative determination of plant phenolics in Urtica dioica extracts by high-performance liquid chromatography coupled with tandem mass spectrometric detection.

A method for quantification of 45 plant phenolics (including benzoic acids, cinnamic acids, flavonoid aglycones, C- and O-glycosides, coumarins, and lignans) in plant extracts was developed, based on reversed phase HPLC separation of extract components, followed by tandem mass spectrometric detection. The phenolic profile of 80% MeOH extracts of the stinging nettle (Urtica dioica L.) herb, root, stem, leaf and inflorescence was obtained by using this method. Twenty-one of the investigated compounds were present at levels above the reliable quantification limit, with 5-O-caffeoylquinic acid, rutin and isoquercitrin as the most abundant. The inflorescence extracts were by far the richest in phenolics, with the investigated compounds amounting 2.5-5.1% by weight. As opposed to this, the root extracts were poor in phenolics, with only several acids and derivatives being present in significant amounts. The results obtained by the developed method represent the most detailed U. dioica chemical profile so far.