P2X7-Receptor Pathway Involvement in the Anti-Inflammatory Activity of Medicinal Plants

Medicinal plants used in European folk medicine attached to Lamiales, Gentianales or Asterales orders are used to treat inflammatory disorders. Many targets have been identified but to date, implication of purinergic receptor P2X7 activation has not yet been investigated. We managed to evaluate the protective effect on P2X7 activation by plant extracts used as anti-inflammatory in European folk medicine by the YO-PRO-1 uptake dye in vitro bioassay. Results revealed that among our selected plants, species from Scrophularia and Plantago genus were able to decrease significantly P2X7 activation (>50 % at 0.1 and 1 μg/mL). UPLC/MS, dereplication and metabolomic analysis of Scrophularia extracts, allowed us to identify the cinnamoyl-iridoid harpagoside as putative inhibitor of P2X7 activation. These results open a new research field regarding the anti-inflammatory mechanism of cinnamoyl-iridoids bearing plants, which may involve the P2X7 receptor.

Metabolomic Profiling of Bipolar Disorder by 1H-NMR in Serbian Patients

Bipolar disorder (BD) is a brain disorder that causes changes in a person's mood, energy, and ability to function. It has a prevalence of 60 million people worldwide, and it is among the top 20 diseases with the highest global burden. The complexity of this disease, including diverse genetic, environmental, and biochemical factors, and diagnoses based on the subjective recognition of symptoms without any clinical test of biomarker identification create significant difficulties in understanding and diagnosing BD. A ¹H-NMR-based metabolomic study applying chemometrics of serum samples of Serbian patients with BD (33) and healthy controls (39) was explored, providing the identification of 22 metabolites for this disease. A biomarker set including threonine, aspartate, gamma-aminobutyric acid, 2-hydroxybutyric acid, serine, and mannose was established for the first time in BD serum samples by an NMR-based metabolomics study. Six identified metabolites (3-hydroxybutyric acid, arginine, lysine, tyrosine, phenylalanine, and glycerol) are in agreement with the previously determined NMR-based sets of serum biomarkers in Brazilian and/or Chinese patient samples. The same established metabolites (lactate, alanine, valine, leucine, isoleucine, glutamine, glutamate, glucose, and choline) in three different ethnic and geographic origins (Serbia, Brazil, and China) might have a crucial role in the realization of a universal set of NMR biomarkers for BD.

Identification and Quantification of Selected Benzoxazinoids and Phenolics in Germinated Spelt (Triticum spelta)

In this study, we investigated the effects of germination on the secondary metabolite composition in spelt grains. Germination significantly increased the content of various metabolites in free and bound forms. Benzoxazinoids were the most important compounds in the free fraction of the 96 h germinated grains (MBOA content as the predominant compound was 277.61 ± 15.29 µg/g DW). The majority of phenolic acids were present in the bound fraction, with trans-ferulic acid as the main component, reaching 753.27 ± 95.87 µg/g DW. The often neglected cis-isomers of phenolic acids accounted for about 20% of the total phenolic acids. High levels of apigenin di-C-glycosides were found in spelt grains, and the schaftoside content was most affected by germination, increasing threefold. The accumulation of secondary metabolites significantly increased the antioxidant activity of germinated spelt. According to the results of this study, the content of most bioactive compounds was highest in spelt grains after 96 h of germination. These data suggest that germinated spelt could potentially be valuable for the production of functional foods.

Metabolomics as a Potential Chemotaxonomical Tool: Application on the Selected Euphorbia Species Growing Wild in Serbia

Chemotaxonomy presents various challenges that need to be overcome in order to obtain valid and reliable results. Individual genetic and environmental variations can give a false picture and lead to wrong conclusions. Applying a holistic approach, based on multivariate data analysis, these challenges can be overcome. Thus, a metabolomics approach has to be optimized depending on the subject of research. We used ¹H NMR-based metabolomics as a potential chemotaxonomic tool on the selected Euphorbia species growing wild in Serbia. Principal components analysis (PCA), soft independent modeling by class analogy (SIMCA) and Orthogonal Projections to Latent Structures Discriminant Analysis (OPLS-DA) were used to analyze obtained NMR data in order to reveal chemotaxonomic biomarkers. The standard protocol for plant metabolomics was optimized aiming to extract more specific metabolites, which are characteristic for the Euphorbia genus. The obtained models were validated, which revealed that variables unique for each species were associated with certain classes of molecules according to literature data. In E. salicifolia, acacetin-7-O-glycoside (not found before in the species) was detected, and the structure of the aglycone part was solved based on 2D NMR data. In the presented paper, we have shown that metabolomics can be successfully used in Euphorbia chemotaxonomy.

Metabolomics study of the desiccation and recovery process in the resurrection plants Ramonda serbica and R. nathaliae

INTRODUCTION

Ramonda serbica and R. nathaliae are resurrection plants that have the remarkable ability to survive the complete desiccation of their vegetative organs (i.e. leaves, stem, roots) during periods of drought and rapidly revive when rewatered and rehydrated.

OBJECTIVE

To investigate metabolic changes in R. serbica and R. nathaliae during their desiccation and recovery process METHODS: Proton nuclear magnetic resonance (¹ H-NMR) and gas chromatography-mass spectrometry (GC-MS)-based metabolomics approach coupled with multivariate data analysis was utilised to identify the metabolomes of the plants from 90 biological replicates.

RESULTS

Sucrose and the polyphenolic glycoside myconoside were predominant in almost equal amounts in all samples studied, regardless of their water content at sampling. During the dehydration process, a decrease in the relative content of fructose, galactose, and galactinol was observed while the contents of those metabolites were preserved in the partially rehydrated plants. Raffinose and myo-inositol were accumulated in dry samples.

CONCLUSION

Using ¹ H-NMR and GC-MS as two complementary analytical platforms provided a more complete picture of the metabolite composition for investigation of the desiccation and recovery process in resurrection plants.

Latex Metabolome of Euphorbia Species: Geographical and Inter-Species Variation and its Proposed Role in Plant Defense against Herbivores and Pathogens

Based on the hypothesis that the variation of the metabolomes of latex is a response to selective pressure and should thus be affected differently from other organs, their variation could provide an insight into the defensive chemical selection of plants. Metabolic profiling was used to compare tissues of three Euphorbia species collected in diverse regions. The metabolic variation of latexes was much more limited than that of other organs. In all the species, the levels of polyisoprenes and terpenes were found to be much higher in latexes than in leaves and roots of the corresponding plants. Polyisoprenes were observed to physically delay the contact of pathogens with plant tissues and their growth. A secondary barrier composed of terpenes in latex and in particular, 24-methylenecycloartanol, exhibited antifungal activity. These results added to the well-known role of enzymes also present in latexes, show that these are part of a cooperative defense system comprising biochemical and physical elements.

Integration of dry-column flash chromatography with NMR and FTIR metabolomics to reveal cytotoxic metabolites from Amphoricarpos autariatus

Metabolomics generate a profile of small molecules from plant extracts, which could be directly responsible for bioactivity effects. Using dry-column flash chromatography enabled a rapid and inexpensive method for the very efficient separation of plant extract with a high resolution. This separation method coupled to NMR and FTIR-based metabolomics is applied to identify bioactive natural products. OPLS multivariate analysis method, was used for correlation the chemical composition of the plant extracts, Amphoricarpos autariatus, with the results of cytotoxic activity against Human cervical adenocarcinoma cell line (HeLa) and epithelial lung cancer cell line (A549). In this way, the highest contribution to the cytotoxic activity was recorded for the guaianolide sesquiterpene lactones named amphoricarpolides. The compounds indicated as bioactive after metabolomics analysis were tested, and their cytotoxic activity were confirmed.

Metabolic Profiling of Saponin-Rich Ophiopogon japonicus Roots Based on 1H NMR and HPTLC Platforms

Ideally, metabolomics should deal with all the metabolites that are found within cells and biological systems. The most common technologies for metabolomics include mass spectrometry, and in most cases, hyphenated to chromatographic separations (liquid chromatography- or gas chromatography-mass spectrometry) and nuclear magnetic resonance spectroscopy. However, limitations such as low sensitivity and highly congested spectra in nuclear magnetic resonance spectroscopy and relatively low signal reproducibility in mass spectrometry impede the progression of these techniques from being universal metabolomics tools. These disadvantages are more notorious in studies of certain plant secondary metabolites, such as saponins, which are difficult to analyse, but have a great biological importance in organisms. In this study, high-performance thin-layer chromatography was used as a supplementary tool for metabolomics. A method consisting of coupling ¹H nuclear magnetic resonance spectroscopy and high-performance thin-layer chromatography was applied to distinguish between Ophiopogon japonicus roots that were collected from two growth locations and were of different ages. The results allowed the root samples from the two growth locations to be clearly distinguished. The difficulties encountered in the identification of the marker compounds by ¹H nuclear magnetic resonance spectroscopy was overcome using high-performance thin-layer chromatography to separate and isolate the compounds. The saponins, ophiojaponin C or ophiopogonin D, were found to be marker metabolites in the root samples and proved to be greatly influenced by plant growth location, but barely by age variation. The procedure used in this study is fully described with the purpose of making a valuable contribution to the quality control of saponin-rich herbal drugs using high-performance thin-layer chromatography as a supplementary analytical tool for metabolomics research.

Antibacterial and Antibiofilm Activity of Flavonoid and Saponin Derivatives from Atriplex tatarica against Pseudomonas aeruginosa

A new flavonoid glucoside derivative, patuletin 3 -O-(2- O-feruloyl)-β-d-glucuronopyranosyl-(1→2)-β-d-glucopyranoside, named atriplexin IV (1), and three new triterpenoid saponin derivatives, two sulfonylated, β-d-glucopyranosyl-3 -O-(2- O-sulfo-β-d-galactopyranosyl)-(1→2)-α-l-arabinopyranoside-30-alolean-12-en-28-oate (2), named atriplexogenin I, β-d-glucopyranosyl-3- O-(2- O-sulfo-β-d-galactopyranosyl)-(1→2)-α-l-arabinopyranoside)-30-hydroxyolean-12-en-28-oate (3), named atriplexogenin II, and β-d-glucopyranosyl-3 -O-(β-d-glucopyranosyl-(1→2)-β-d-galactopyranosyl-(1→2)-α-l-arabinopyranoside)-30-alolean-12-en-28-oate (4), named atriplexogenin III, were isolated by silica gel column and semipreparative HPLC chromatography from the n-butanol extract of the salt marsh plant Atriplex tatarica. In addition, two known secondary metabolites, patuletin3 -O-β-d-apiofuranosyl-(1‴→2″)-β-d-glucopyranoside (5) and patuletin 3 -O-5‴- O-feruloyl-β-d-apiofuranosyl-(1‴→2″)-β-d-glucopyranoside (6), were isolated for the first time from A. tatarica. The structures of the isolated compounds were elucidated by 1D and 2D NMR, HRESIMS, IR, and UV data. Antibacterial activity by the microdilution method and antibiofilm activity against P. aeruginosa were assessed. Compound 5 possesses significant antibacterial activity, while the most potent antibiofilm agent is compound 2.

Grape Seed Polyphenols and Fatty Acids of Autochthonous Prokupac Vine Variety from Serbia

Grape pomace (grape skin, seeds, and stems) represents a valuable source of bioactive compounds, thus the interest in making use of these wine waste products is increasing. Prokupac is an autochthonous Serbian variety of black grape with a long tradition in production of red wine. Identification of the superficial polyphenolic compounds by LC/MS revealed presence of 19 compounds including hydroxybenzoic acid derivatives, ellagic acid derivatives, flavan-3-ol monomers, proanthocyanidins, and flavonols. Catechin and epicatechin together with proanthocyanidins were the most abundant compounds and the highest content of phenolic compounds was determined in Prokupac clones 43/1, 40/1, and 40/2. Grape seed oil consisted of dominantly UFA (87-95 %) where methyl linoleate was the most abundant in all samples (69-81 %). Palmitic (3-8 %) and stearic acid (2-4 %) methyl esters were dominant SFA. Prokupac clone 43/3 was the most abundant in UFA (95 %) with the lowest percentage of SFA (5 %), while clones 41/1 and 43/5 had the lowest percentage of UFA (87 %) and the highest content of SFA (13 %). Favorable chemical profile of Prokupac clone seeds implicates its potential to be used as a raw material in further processing and possibility to be included as one of the quality parameters in further selection of the most interesting Prokupac clone.

Metabolomics study of Populus type propolis

Herein, we propose rapid and simple spectroscopic methods to determine the chemical composition of propolis derived from various Populus species using a metabolomics approach. In order to correlate variability in Populus type propolis composition with the altitude of its collection, NMR, IR, and UV spectroscopy followed by OPLS was conducted. The botanical origin of propolis was established by comparing propolis spectral data to those of buds of various Populus species. An O2PLS method was utilized to integrate two blocks of data. According to OPLS and O2PLS, the major compounds in propolis samples, collected from temperate continental climate above 500m, were phenolic glycerides originating from P. tremula buds. Flavonoids were predominant in propolis samples collected below 400m, originating from P. nigra and P. x euramericana buds. Samples collected at 400-500m were of mixed origin, with variable amounts of all detected metabolites.

Metabolic changes in Euphorbia palusrtis latex after fungal infection

The variations of metabolic profile of the latex of wild-growing Euphorbia palustris was carried out using multivariate analysis of ¹H NMR spectral data. One population was infected with fungi Fusarium sporotrichioides, Fusarium proliferatum and Alternaria alternata, while the other consisted of healthy plant species. The non-polar metabolites of latex extracts such as benzoyl ingenol-laurate, amyrin decadienoate esters, cis-1,4-polyisoprene, and 24-methylenecycloartanol were identified using ¹H and 2D NMR spectra. Principal component analysis of ¹H NMR data provided a clear discrimination between the latex of infected and healthy plants. Minimum inhibitory concentration and minimum fungicidal concentration values of the latex extracts of healthy and infected plants were determined. The latex of infected plants was found to contain higher levels of benzoyl ingenol-laurate and 24-methylenecycloartanol, of which concentrations were strongly correlated with the antifungal activities of the latex.

Phenolic Compounds from Atriplex littoralis and Their Radiation-Mitigating Activity

From the aerial parts of Atriplex littoralis, three new flavonoid glycosides named atriplexins I-III (1-3), a known flavonoid glycoside, spinacetin 3-O-β-d-glucopyranoside (4), arbutin (5), and 4-hydroxybenzyl-β-d-glucopyranoside (6) were isolated. Their structures were elucidated on the basis of detailed spectroscopic analysis, including 1D and 2D NMR (COSY, NOESY, TOCSY, HSQC, HMBC) and HRESITOF MS data. The compounds were tested for in vitro protective effects on chromosome aberrations in peripheral human lymphocytes using a cytochalasin-B-blocked micronucleus (MN) assay in a concentration range of 0.8-7.4 μM of final culture solution. Chromosomal damage was induced by 2 Gy of γ-radiation on binucleated human lymphocytes, and the effects of the compounds were tested 2 to 19 h after irradiation. The frequency of micronuclei (MNi) was scored in binucleated cells, and the nuclear proliferation index was calculated. The highest prevention of in vitro biochemical and cytogenetic damage of human lymphocytes induced by γ-radiation was exhibited by 3 (reduction of MN frequency by 31%), followed by 4 and 6.

Chamomile and marigold tea: chemical characterization and evaluation of anticancer activity

With the aim to evaluate the selectivity in the antitumor action, the cytotoxic activity of chamomile and marigold tea was tested against various malignant cell lines and against healthy immunocompetent peripheral blood mononuclear cells (PBMC). Chemical profiles of chamomile and marigold infusions and decoctions were analyzed by liquid chromatography/mass spectrometry; their total phenolic content and radical scavenging activity were determined, too. Results from present research demonstrate that chamomile and marigold tea exert selective dose-dependent cytotoxic action against target cancer cells. It is noteworthy that cytotoxicity of tea prepared from Calendula officinalis is remarkably higher in comparison to that from Matricaria recutita tea. The cytotoxic effect of chamomile tea is very weak to healthy PBMC, while the effect of marigold tea on PBMC is more pronounced. Marigold tea exerts highly selective antitumor effect especially to melanoma Fem-x cells in comparison to the action to normal healthy PBMC. Chemical analyses show that dominant phenolic compounds in examined infusions and decoctions are flavonoid glycosides and hydroxycinnamic acid derivatives. There are no considerable differences in total phenolic content and antioxidant activity between examined infusions. Antitumor potential of chamomile and marigold tea should be further investigated.

Chemical composition of currant seed extracts and their protective effect on human lymphocytes DNA

On the basis of LC/UV/MS analysis, 35 compounds from the extracts of seeds of black, red, and white currants (2 cultivars of each) were identified. Black currants cultivars contained protocatechuic acid and p-hydroxybenzoic acid, and traces of nitril containing phenolic acids. The presence of synapoyl glucoside was characteristic for cv. Malling Jewel. Sesquiterpenoid glycosides and carboxymethylindol glycosides were present mainly in white and red currant cultivars. Blackcurrant seeds contained higher amounts of flavonoids, especially rutin, isoquercetin, and taxifolin. The currant seed extracts were tested for in vitro protective effect on chromosome aberrations in peripheral human lymphocytes using cytochalasin-B blocked micronucleus (CBMN) assay. The frequency of MN was scored in binucleated cells, and the cultivars of black currants showed the best antioxidant potential. At a concentration of only 0.17 mg/mL, extract of the seed cv. Malling Jewel effected a decrease in the frequency of MN of 60% compared with control cell cultures.

PRACTICAL APPLICATION

Our results provide evidence of protective effects of currant seed extracts and isolated pure compounds on cytogenetic damages in human lymphocytes. Thus, currant seed extracts could exert beneficial effects in quite a few diseases, for many of the biological actions have been attributed to their antioxidant properties.

Anti-inflammatory and Gastroprotective Properties of Hypericum Richeri Oil Extracts

Oil extracts of flowering tops of Hypericum richeri Vill. prepared in three different ways were evaluated for chemical composition, and Anti-inflammatory and Gastroprotective activities. An HPLC method was developed for determination of two dominant flavonoids, quercetin and I3,II8-biapigenin. The carrageenan-induced rat paw edema test was used for screening the antiinflammatory activity, while indomethacin-induced rat gastric mucosa damage test was used for evaluation of gastroprotective activity. The oil extract prepared by maceration with 96% ethanol, followed by extraction with sunflower oil by heating on a water bath, exhibited the highest antiinflammatory (38.4 %) and gastroprotective activities (gastric damage score of 0.9). The same oil extract had the highest content of quercetin (49 μg/mL) and I3,II8-biapigenin (60 μg/mL). These results approve the usage of oil extracts of H. richeri as an antiinflammatory and gastroprotective agent.