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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.

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.

Extraction of plant secondary metabolites is an essential step in isolation of natural products. Non-optimized extraction conditions can lead to losses, degradation and modification of the biomolecules. In this paper, the influence of different solvent mixtures, solvent amounts, temperature, extraction time, and procedures for defatting on yield and profile of various classes of secondary metabolites was investigated. Rumex alpinus was used for the extraction of anthraquinones, Glycine max for isoflavonoids, Chaerophyllum bulbosum for flavonoids and phenolic acids, Anthriscus sylvestris for lignans and coumarins, alkaloids were extracted from Lupinus albus and sesquiterpene lactones from Artemisia absinthium. Extraction efficiency was evaluated by use of LC-DAD-ESI-MS/MS. The compromise extraction solvent for all of the examined compounds is 80 % methanol, mixed in ratio 13 : 1 with plant material. Maceration should last for six hours, repeated four times with fresh solvent. Defatting of the extracts does not lead to significant losses of the compounds of interest. It is acceptable to use extraction and evaporation temperature of 60?C, while the extracts should be stored in the dark, on -20?C. [Projekat Ministarstva nauke Republike Srbije, br. 172058]

Polygonum maritimum is a traditional herbal remedy that produces abundant flavonoid secondary metabolites. The ethanol extract of P. maritimum aerial parts (POM) was chemically characterized and tested for antimicrobial properties and cytotoxicity. Results of LC-MS/MS analysis showed high contents of gallic acid, epigallocatechin gallate and catechin, and significant amounts of quercetin-3-O-galactoside and quercetin-3-O-glucoside. Evaluation of the antifungal properties revealed that POM induced notable growth inhibition of Alternaria alternata (34.3%), Penicillium spp. (30.6%), Fusarium semitectum (20.2%) and Aspergillus spp. (19.6%). Evaluation of cytotoxicity against human hepatoma HepG2 cells included monitoring the effects of both POM alone and its combination with cytostatic doxorubicin (Dox). Cell viability, apoptosis and cell cycle distribution and the expression of antioxidant enzymes (superoxide-dismutases SOD1 and SOD2 and catalase) were determined. A dose-dependent decrease in cell viability was detected, but a remarkably stronger effect was obtained when POM and Dox were applied in combination as compared to individual treatments. IC 50 values were determined to be 393 μg/mL (POM) and 2.24 μg/mL (Dox) in combination, but 1153 μg/mL (POM) and 12.56 μg/mL (Dox) in a single treatment. The value of the Loewe index, determined for IC 50 , was notably lower than 1 (LI=0.51), clearly indicating synergism of POM and Dox. Additionally, POM and POM +Dox induced early/late apoptosis and G2/M cell cycle arrest. Furthermore, POM increased, while Dox decreased the expression levels of SODs and catalase. The obtained results encourage further examination of the potential use of POM in modern phytotherapy.

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.