Phytochemical investigation of Volutaria lippii and evaluation of the antioxidant activity

Volutaria lippii (L.) Cass. ex Maire, syn. Centaurea lippii (L.), (Asteraceae) is a plant from the central region of Algeria, considerably distributed in all Mediterranean areas. Herein, the antioxidant activity of the three derived fractions [chloroform (CHCl3), ethyl acetate (EtOAc) and n-butanol (n-BuOH)] of the 70% methanol extract of the aerial parts (leaves and flowers), was assessed by using CUPRAC, ABTS, DPPH free radical scavenging, and β-carotene bleaching methods. The results obtained allowed to guide the fractionation of EtOAc and n-BuOH fractions by CC followed by purification by TLC and reverse phase HPLC. A guaianolide glucoside, 3β-hydroxy-11β,13-dihydrodehydrocostuslactone 8α-O-(6'-acetyl-β-glucopyranoside) (1), never reported in the literature, was isolated together with other known compounds (2-14). Their structures were elucidated by the extensive use of 1 D- and 2 D-NMR experiments along with ESI-MS analyses and with comparison with literature data.

A potential antiviral against COVID-19 obtained from Byrsonima coccolobifolia leaves extract

In this study, we specifically focused on the crude methanolic leaf extract of Byrsonima coccolobifolia, investigating its antifungal potential against human pathogenic fungi and its antiviral activity against COVID-19. Through the use of high-performance liquid chromatography coupled with electrospray ionization ion trap tandem mass spectrometry, direct infusion electrospray ionization ion trap tandem mass spectrometry, and chromatographic dereplication procedures, we identified galloyl quinic acid derivatives, catechin derivatives, proanthocyanidins, and flavonoid glycosides. The broth dilution assay revealed that the methanolic leaf extract of B. coccolobifolia exhibits antifungal activity against Cryptococcus neoformans (IC50 = 4 μg/mL). Additionally, docking studies were conducted to elucidate the interactions between the identified compounds and the central residues at the binding site of biological targets associated with COVID-19. Furthermore, the extract demonstrated an in vitro half-maximum effective concentration (EC50 = 7 μg/mL) and exhibited significant selectivity (>90%) toward SARS-CoV-2.

Phytochemical Investigation and Biofilm-Inhibitory Activity of Bachtiari Savory (Satureja bachtiarica Bunge) Aerial Parts

Satureja bachtiarica is an endemic plant from the Lamiaceae family, growing in the Zagros mountain range in Iran. Even if S. bachtiarica is reported to possess many biological activities, little is known about its chemical composition. For this reason, in the present research, a phytochemical investigation of this species was carried out. To have a preliminary metabolite profile of S. bachtiarica, the n-BuOH extract was analyzed using LC-ESI/LTQOrbitrap/MS/MS in negative ion mode, allowing the identification of specialized metabolites belonging to flavonoid, monoterpene, indol, phenylpropanoid, phenolic, lignan, coumarin, biphenyl, and triterpene classes. The LC-MS/MS analysis guided the isolation of compounds, and their structures were characterized using spectroscopic methods including 1D- and 2D-NMR experiments and HRMSn analysis. In this way, a compound never reported before belonging to the biphenyl class was identified. Total flavonoid content of the extract along with the antioxidant activity were assessed. Based on the traditional uses of S. bachtiarica suggesting potential antibacterial properties, an evaluation of the biofilm inhibitory activity of the extract and isolated compounds against mature biofilms of Acinetobacter baumannii, Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa, and Staphylococcus aureus, as well as their influence on the metabolism of sessile bacterial cells, was conducted. The results evidenced that some compounds including parmentin B, biphenyls, and 1-(1H-indole-3-carboxylate)-β-D-glucopyranoside might inhibit some changes occurring in the bacterial cells, which increases their virulence. In particular, biphenyl derivatives at a concentration of 80 μg/mL were capable of limiting remarkably the mature biofilms of A. baumannii and L. monocytogenes remarkably at a percentage ranging between 52.76% and 75.02%, and they reached an inhibition percentage of 69.28 % against E. coli. Biphenyl derivatives were also effective in exerting an inhibitory action against the mature biofilm of P. aeruginosa (inhibition ranging from 59.38% to 81.08%) and Staphylococcus aureus (inhibition percentage reached 82.94%). Of note, the biphenyl derivatives resulted in being capable of acting on the metabolism of the cells within the biofilm of all five pathogens.

Metabolite Profiling, through LC-ESI/LTQOrbitrap/MS Analysis, of Antioxidant Extracts from Physalis alkekengi L

Due to the increasing use of Physalis alkekengi L. as a food supplement and starting material for tea preparation, a comprehensive analysis of green extracts was performed. Two different extraction methods were applied to yellow Physalis alkekengi L. fruit and calyx and compared: hydroalcoholic extraction and decoction. Characterization of the metabolome of the calyx and fruit of yellow Physalis alkekengi L. was performed by LC-ESI/LTQOrbitrap/MS followed by LC-ESI/LTQOrbitrap/MS/MS to identify 58 phytocompounds using the two different extraction techniques. Subsequently, through preliminary spectrophotometric assays followed by cell studies, the antioxidant activity of the different Physalis alkekengi L. extracts were evaluated. It was found that Physalis alkekengi L. extracts are a good source of metabolites such as flavonoids, organic acids, phenylpropanoids, physalins and carotenoids, with various biological activities, in particular, antioxidant activity capable of reducing the production of free radicals in intestinal Caco-2 cells. For the first time, an integrated approach (metabolomics approach and antioxidant evaluation) was applied to the study of Physalis alkekengi green extracts and decoctions, the green extraction method mostly used in herbal preparations. An interesting finding was the high antioxidant activity shown by these extracts.

Demethylcalabaxanthone from Garcinia mangostana Exerts Antioxidant Effects through the Activation of the Nrf2 Pathway as Assessed via Molecular Docking and Biological Evaluation

Nuclear factor erythroid 2-related factor 2 (Nrf2) pathway activation promotes the expression of antioxidant enzymes in response to rising oxidative stress, resulting in reactive oxygen species (ROS) detoxification and playing a central role in the maintenance of intracellular redox homeostasis and regulation of inflammation. Moreover, the biological effects of Nrf2 pathway activation contribute to reducing apoptosis and enhancing cell survival. The activity of Nrf2 is negatively regulated by Kelch-like ECH-associated protein 1 (Keap1). Prompted by the recent results reporting the impact of xanthone metabolites on oxidative stress, cancer, and inflammation, the antioxidant properties of xanthones isolated from Garcinia mangostana (γ-mangostin, α-mangostin, 8-deoxygartanin, demethylcalabaxanthone, garcinone D) were assessed. In particular, the capability of these natural products to disrupt the interaction between Kelch-like ECH-associated protein 1 (Keap1) and nuclear factor erythroid 2-related factor 2 (Nrf2), triggering the activation of the Nrf2-mediated pathway, was evaluated using molecular docking experiments and in vitro tests. The modulation of some key Nrf2-related mediators like glutathione (GSH) and lactate dehydrogenase (LDH) to highlight a possible direct antioxidant effect was investigated. Among the tested compounds, demethylcalabaxanthone showed an indirect antioxidant effect, as corroborated by a Western blot assay, displaying a significant increase in the translocated protein upon its administration.

Corylus avellana "Nocciola Piemonte": metabolomics focused on polar lipids and phenolic compounds in fresh and roasted hazelnuts

The common hazel plant (Corylus avellana L., Betulaceae) is one of the most popular tree nuts widespread in Europe and Asia. In Italy, there are different cultivars among which the cultivar affording the valuable hazelnut "Tonda Gentile Trilobata," also known as "Tonda Gentile delle Langhe," covered by the Protected Geographical Indication (PGI) label "Nocciola Piemonte" (NP), known for its sweetness, cooked-bread aroma, and the low intensity of the burnt aroma. In order to obtain a detailed and in-depth characterization of the polar fraction of fresh (NPF) and roasted (NPR) kernels of NP the analysis of the n-butanol extracts by liquid chromatography coupled to electrospray ionization and high-resolution mass spectrometry (LC-ESI/HRMS) was carried out. Moreover, to evaluate the quantitative distribution of the most representative polar lipids in NPF and NPR, the analysis by liquid chromatography combined with tandem mass spectrometry (LC-MS/MS) was performed. To unambiguously identify the phenolic compounds highlighted by the LC-ESI/HRMS profiles, they were isolated from the n-butanol extract and characterized by Nuclear Magnetic Resonance (NMR) experiments. Finally, the ability of the isolated compounds to exert radical scavenging activity and to inhibit the lipid peroxidation induced by H2O2 or H2O2/Fe2+ was tested by Trolox Equivalent Antioxidant Capacity (TEAC) and thiobarbituric acid reactive substances (TBARS) assays, respectively. The LC-ESI/HRMS allowed to ascertain the presence of phenolic compounds and multiple classes of polar lipids including phospholipids, glycolipids, sphingolipids, and oxylipins. The quantitative analysis highlighted in NPR fraction a lipid content three times higher than in NPF, evidencing lyso-phospholipids and phospholipids as the most represented lipid classes in both NPF and NPR, together accounting for 94 and 97% of the considered lipids, respectively. Furthermore, phytochemical analysis permitted to identify flavonoid and diarylheptanoid derivatives. In particular, quercetin 3-O-β-D-galactopyranosyl-(1→2)-β-D-glucopyranoside and myricetin-3-O-α-L-rhamnopyranoside showed the highest antioxidant activity, exhibiting TEAC values similar to that of quercetin, used as reference compound (2.00 ± 0.03 and 2.06 ± 0.03 mM vs 2.03 ± 0.03 mM, respectively). Moreover, most of the tested compounds were found to reduce lipid peroxidation induced by H2O2 and H2O2/Fe2+ more than curcumin used as positive control, with myricetin-3-O-α-L-rhamnopyranoside determining 44.4 % and 34.1 % inhibition percentage, respectively.

LC-MS and NMR Based Plant Metabolomics: A Comprehensive Phytochemical Investigation of Symphytum anatolicum

The application of metabolomics to the study of plants is growing because of the current development of analytical techniques. The most commonly used analytical technology driving plant metabolomics studies is Mass Spectrometry (MS) coupled to liquid chromatography (LC). In recent years, Nuclear Magnetic Resonance (NMR) spectroscopy, not requiring a previous chromatographic separation, has been receiving growing attention for metabolite fingerprinting of natural extracts. Herein, an integrated LC-MS and 1H NMR metabolomic approach provided a comprehensive phytochemical characterization of Symphytum anatolicum whole plant, taking into account both primary and specialized metabolites. Moreover, the NMR analyses provided direct quantitative information. Species belonging to the Symphytum genus, known as comfrey, have shown several biological activities including anti-inflammatory, analgesic, hepatoprotective, antifungal, and antibacterial. The LC-MS profile showed the presence of 21 main specialized metabolites, belonging to the classes of flavonoids, phenylpropanoids, salvianols, and oxylipins. The 1H NMR spectrum revealed the occurrence of metabolites including organic acids, phenolics, flavonoids, sugars, and amino acids. A quantitative analysis of these metabolites was performed and their concentration was obtained with respect to the known concentration of TSP, by means of the software package Chenomx which allows quantification of individual components in the NMR spectra. Furthermore, the phenolic content, antioxidant activity, glucosidase, and tyrosinase inhibitory activity of S. anatolicum extract were evaluated. The resulting bioactivity profile suggests how S. anatolicum represents a source of metabolites with health-promoting activity.

Schinus terebinthifolius Raddi (Brazilian pepper) leaves extract: in vitro and in vivo evidence of anti-inflammatory and antioxidant properties

The aim of this work was to evaluate the anti-inflammatory and antioxidant effects of ethyl acetate extract obtained from the leaves of Brazilian peppertree Schinus terebinthifolius Raddi (EAELSt). Total phenols and flavonoids, chemical constituents, in vitro antioxidant activity (DPPH and lipoperoxidation assays), and cytotoxicity in L929 fibroblasts were determined. In vivo anti-inflammatory and antioxidant properties were evaluated using TPA-induced ear inflammation model in mice. Phenol and flavonoid contents were 19.2 ± 0.4 and 93.8 ± 5.2 of gallic acid or quercetin equivalents/g, respectively. LC-MS analysis identified 43 compounds, of which myricetin-O-pentoside and quercetin-O-rhamnoside were major peaks of chromatogram. Incubation with EAELSt decreased the amount of DPPH radical (EC50 of 54.5 ± 2.4 µg/mL) and lipoperoxidation at 200-500 µg/mL. The incubation with EAELSt did not change fibroblast viability up to 100 µg/mL. Topical treatment with EAELSt significantly reduced edema and myeloperoxidase activity at 0.3, 1, and 3 mg/ear when compared to the vehicle-treated group. In addition, EAELSt decreased IL-6 and TNF-α levels and increased IL-10 levels. Besides, it modulated markers of oxidative stress (reduced total hydroperoxides and increased sulfhydryl contents and ferrium reduction potential) and increased the activity of catalase and superoxide dismutase, without altering GPx activity.

Metabolite Profiling for Typization of "Rucola della Piana del Sele" (PGI), Eruca sativa, through UHPLC-Q-Exactive-Orbitrap-MS/MS Analysis

In August 2020, the Eruca sativa cultivar "Rucola della Piana del Sele" obtained from the European Union the prestigious PGI (protected geographical indication) label, which certifies the uniqueness of its characteristics and increases its prestige both nationally and, above all, internationally. This plant is recognized as a product of excellence, with a unique flavor and unmistakable aroma. Therefore, since there are no methods to characterize the PGI product, a metabolomic approach was applied to characterize E. sativa grown in the Piana del Sele and different geographical areas. As E. sativa has very wide cultivation, this study sought to compare the metabolite profiles of rocket grown in Piana del Sele, Bergamo, and Brescia, as well as in Switzerland, making a comparison also with the metabolite profile of E. sativa grown spontaneously. To determine the best procedure to distinguish "Rucola della Piana del Sele" from the others, different extraction procedures were carried out using different solvents and fresh or freeze-dried plant matrices. The different extracts were analyzed by liquid chromatography coupled with high-resolution mass spectrometry experiments, using chemometric analyses to identify biomarker metabolites that characterize the PGI product. The LC-ESI-Q-Exactive-MS/MS profiles of methanol and hydroalcoholic extracts of different cultivars of E. sativa were found to be rich in bioactive compounds such as glucosinolates, glycosylated flavonoids, fatty acids, and lipids. The LCMS data were analyzed by principal component analysis (PCA); the score scatter plot shows significant separation among Eruca samples grown in different geographical areas. In detail, loading the scatter plot revealed Eruca grown in Piana del Sele to be richer than other cultivars in glycosylated quercetin 3,3',4'-O-triglucoside (7), quercetin-3,4'-O-diglucoside-3'-O-(6-sinapoyl-glucoside) (10), and quercetin diglucoside (30). Finally, considering the biological interest in erucin, the myrosinase product of glucoerucin, the latter was quantified in the extracts by LC-ESI/QTrap/MS/MS using the multiple reaction monitoring (MRM) method; E. sativa from Piana del Sele showed the highest content of glucoerucin.

LC-MS- and 1H NMR-Based Metabolomics to Highlight the Impact of Extraction Solvents on Chemical Profile and Antioxidant Activity of Daikon Sprouts (Raphanus sativus L.)

Currently, the interest of consumers towards functional foods as source of bioactive compounds is increasing. The sprouts of Raphanus sativus var longipinnatus (Brassicaceae) are "microgreens" popular, especially in gourmet cuisine, for their appealing aspect and piquant flavour. They represent a functional food due to their high nutritional value and health-promoting effects. Herein, the sprouts of daikon were extracted by different solvent mixtures to highlight how this process can affect the chemical profile and the antioxidant activity. An in-depth investigation based on a preliminary LC-ESI/LTQOrbitrap/MS profiling was carried out, leading to the identification of nineteen compounds, including glucosinolates and hydroxycinnamic acid derivatives. An undescribed compound, 1-O-feruloyl-2-O-sinapoyl-β-D-glucopyranoside, was isolated, and its structure was elucidated by NMR spectroscopy. The phenolic content and radical scavenging activity (DPPH and TEAC assays), along with the ability to activate Nrf2 (Nrf2-mediated luciferase reporter gene assay) of polar extracts, were evaluated. The results showed the highest antioxidant activity for the 70% EtOH/H2O extract with a TEAC value of 1.95 mM and IC50 = 93.97 µg/mL in the DPPH assay. Some 50% and 70% EtOH/H2O extracts showed a pronounced concentration-dependent induction of Nrf2 activity. The extracts of daikon sprouts were submitted to 1H NMR experiments and then analyzed by untargeted and targeted approaches of multivariate data analysis to highlight differences related to extraction solvents.

Anti-inflammatory Activity of Tanshinone-Related Diterpenes from Perovskia artemisioides Roots

Perovskia artemisioides is a perennial and aromatic plant widely distributed in the Baluchestan region of Iran. Phytochemical analysis of a n-hexane extract of P. artemisioides roots, guided by an analytical approach based on LC-ESI/LTQOrbitrap/MS/MS, yielded six previously undescribed diterpenoid compounds (2, 9-11, 16, and 20), and 19 known diterpenoids, for which the structures were elucidated by 1D and 2D NMR experiments. Some of the isolated compounds showed significant anti-inflammatory activity using J774A.1 macrophage cells stimulated with Escherichia coli lipopolysaccharide. In particular, compounds 6, 8, 17, 18, 20, and 22 significantly inhibited the release of nitric oxide and the expression of related pro-inflammatory enzymes, such as inducible nitric oxide synthase and cycloxygenase-2. Moreover, two compounds that showed the highest activity in reducing nitric oxide release (6 and 18) were tested to evaluate their effects on nitrotyrosine formation and reactive oxygen species release. Both compounds inhibited ROS release and, in particular, compound 6 also inhibited nitrotyrosine formation at all tested concentrations, thus indicating a significant antioxidant potential.

A New Bloody Pulp Selection of Myrobalan (Prunus cerasifera L.): Pomological Traits, Chemical Composition, and Nutraceutical Properties

A new accession of myrobalan (Prunus cerasifera L.) from Sicily (Italy) was studied for the first time for its chemical and nutraceutical properties. A description of the main morphological and pomological traits was created as a tool for characterization for consumers. For this purpose, three different extracts of fresh myrobalan fruits were subjected to different analyses, including the evaluation of total phenol (TPC), flavonoid (TFC), and anthocyanin (TAC) contents. The extracts exhibited a TPC in the range 34.52-97.63 mg gallic acid equivalent (GAE)/100 g fresh weight (FW), a TFC of 0.23-0.96 mg quercetin equivalent (QE)/100 g FW, and a TAC of 20.24-55.33 cyanidine-3-O-glucoside/100 g FW. LC-HRMS analysis evidenced that the compounds mainly belong to the flavonols, flavan-3-ols, proanthocyanidins, anthocyanins, hydroxycinnamic acid derivatives, and organic acids classes. A multitarget approach was used to assess the antioxidant properties by using FRAP, ABTS, DPPH, and β-carotene bleaching tests. Moreover, the myrobalan fruit extracts were tested as inhibitors of the key enzymes related to obesity and metabolic syndrome (α-glucosidase, α-amylase, and lipase). All extracts exhibited an ABTS radical scavenging activity that was higher than the positive control BHT (IC₅₀ value in the range 1.19-2.97 μg/mL). Moreover, all extracts showed iron-reducing activity, with a potency similar to that of BHT (53.01-64.90 vs 3.26 μM Fe(II)/g). The PF extract exhibited a promising lipase inhibitory effect (IC₅₀ value of 29.61 μg/mL).

A Comparative UHPLC-Q-Trap-MS/MS-Based Metabolomics Analysis to Distinguish Foeniculum vulgare Cultivars' Antioxidant Extracts

Among the environmental factors, seasonality is the one which most affects the metabolome of a plant. Depending on the harvest season, the plant may have a variable content of certain metabolites and thus may have different biological properties. Foeniculum vulgare is an annual plant whose cultivation creates large amounts of waste rich in bioactive compounds. The present investigation was performed with the aim of determining the amount of biologically active compounds in F. vulgare wastes obtained from varieties of different seasonality. Ten polyphenolic compounds were quantified in the little stems and leaves of Tiziano, Pegaso, and Preludio cultivars by ultra performance liquid chromatography (UPLC) hyphenated to QTRAP mass spectrometry by using the MRM (multiple reaction monitoring) method. The antioxidant activity of hydroalcoholic extracts was then evaluated using TEAC and DPPH spectrophotometric assays, followed by a multivariate statistical analysis to determine the correlation between metabolite expression and antioxidant activity. The Preludio variety, grown in summer, showed a higher content of bioactive compounds, which guarantees it a better antioxidant power; kaempferol 3-O-glucuronide, quercetin 3-O-glucuronide, and quercetin 3-O-glucoside are the polyphenolic compounds that could be mainly responsible for the antioxidant effect of fennel. The PLS chemometric model, which correlated quantitative data obtained by a sensitive and selective LC-ESI-QTrap-MS/MS analysis of antioxidant activity, resulted in a selective tool to detect the compounds responsible for the activity shown by the extracts in chemical tests.

Sicilian Populations of Capparis spinosa L. and Capparis orientalis Duhamel as Source of the Bioactive Flavonol Quercetin

The genus Capparis is a taxon of difficult delimitation that has several species and ecotypes due to its wide heterogeneity, its extreme phenotypic diversity, and the presence of intermediate forms linked to hybridization phenomena. The Sicilian territory hosts numerous wild and cultivated populations of two spp. Capparis spinosa L. and Capparis orientalis Duhamel, which are ecologically and morphologically distinct. The caper has considerable interest and economic value for its medicinal properties, culinary uses, and cultivation characteristics. It is one of the foods with the highest quercetin content. Quercetin is a flavonol with antioxidant, anti-inflammatory, and immunostimulant properties. Recently, patents and clinical studies have highlighted the inhibitory effect of this compound against several SARS-CoV-2 enzymes (MPro, PLPro, and RdRp). Therefore, the aim of this study was to quantify the amount of quercetin in C. spinosa and C. orientalis by LC-ESI/QTrap/MS/MS and to correlate it with the pedoclimatic features. The results obtained showed that quercetin is more abundant in C. orientalis than in C. spinosa. The highest values of quercetin were recorded in C. orientalis flowers, leaves, and flower buttons of volcanic islands with southwest and east warm exposures. In conclusion, the data acquired can provide a good basis for further scientific investigations to support the identification of possible ecotypes as a source of quercetin for food or pharmaceutical purposes.

Scabiosa atropurpurea: A rich source of iridoids with α-glucosidase inhibitory activity evaluated by in vitro and in silico studies

Scabiosa atropurpurea L. subsp. maritima (L.) Arc. (Caprifoliaceae) is a plant widely distributed in the Mediterranean region and represented by 32 taxa in the flora of Turkey. In the present study, an in-depth phytochemical investigation of S. atropurpurea methanol extract of the whole plant was carried out using a combination of LC-ESI-FT-MS and NMR analysis. This approach allowed the isolation and structural elucidation of 28 compounds: 17 iridoids, 7 flavonoids, and 4 phenolic acids. Among these compounds, three previously unreported iridoids named secologanin-methyl-hemiacetal, atropurpurin A, and atropurpurin B were identified. The methanol extract of S. atropurpurea was assayed for its antioxidant and antihyperglycemic activity, showing a potent α-glucosidase inhibitory activity (IC₅₀ = 100 μg/mL), higher than that exerted by acarbose (IC₅₀ = 196 μg/mL), used as the positive control. Thus, the most abundant iridoids were selected to be tested for their antihyperglycemic activity, and molecular docking experiments were carried out to assess the possibility for selected compounds to form complexes with α-glucosidase enzyme active site.

LC-MS-based metabolite profiling of aqueous extract of Pergularia tomentosa L. and its anti-hyperglycemic effect

Objectives

In this study, to find scientific evidence for the traditional use of Pergularia tomentosa as an anti-diabetic remedy, the effects of its aqueous extract on streptozotocin-induced diabetes mellitus in rats were evaluated.

Materials and Methods

Wistar rats were fasted overnight and diabetes mellitus was induced using streptozotocin (50 mg/kg body weight). The rats were randomly and equally divided into four groups (n=5): group I (normoglycaemic control), group II (diabetic rats), group III (diabetic rats treated with 200 mg/kg BW of an aqueous extract of P. tomentosa), group IV (normoglycemic rats treated with 200 mg/kg BW of an aqueous extract of P. tomentosa). Chemical profiling of the aqueous extract was carried out using liquid chromatography coupled with electrospray ionization and multiple-stage linear ion-trap and orbitrap high-resolution mass spectrometry (LC-ESI/LTQOrbitrap/MS/MS). In addition, the quantitative determination of the main cardenolides in the extract was carried out by an analytical approach based on LC coupled to tandem mass spectrometry with ESI source and hybrid triple quadrupole-linear ion trap mass analyzer (LC-ESI/QTrap/MS/MS).

Results

Aqueous extract of P. tomentosa showed a reasonable reduction in blood glucose level. Probably, the P. tomentosa effect on hyperglycemic and hyperlipidemic diabetic animals was associated with antioxidant properties, triglyceride levels, as well as liver enzymes. Meanwhile, LC-ESI/LTQOrbitrap/MS/MS analysis led to identification of double-linked cardenolides along with cardenolides and flavone glycosides as the main bioactive compounds.

Conclusion

The extract decreased the glucose level and induced a beneficial effect on the lipid profile, probably due to the presence of cardenolide glycosides.

Metabolomics Approach to Characterize Green Olive Leaf Extracts Classified Based on Variety and Season

The huge interest in the health-related properties of plant polyphenols to be applied in food and health-related sectors has brought about the development of sensitive analytical methods for metabolomic characterization. Olive leaves constitute a valuable waste rich in polyphenols with functional properties. A (HR)LC-ESI-ORBITRAP-MS analysis with a multivariate statistical analysis approach using PCA and/or PLS-DA projection methods were applied to identify polyphenols in olive leaf extracts of five varieties from the Apulia region (Italy) in two different seasonal times. A total of 26 metabolites were identified, further finding that although metabolites are common among the different cultivars, they differ in the relative intensity of each peak and within each cultivar in the two seasonal periods taken into consideration. The results of the total phenol contents showed the highest content in November for Bambina and Cima di Mola varieties (1816 and 1788 mg/100 g, respectively), followed by Coratina, Leccino, and Cima di Melfi; a similar trend was found for the antioxidant activity and RapidOxy evaluations by reaching in Bambina values of 45 mmol TE/100 g and 85 min of induction time.

The chemical composition of the aerial parts of Stachys spreitzenhoferi (Lamiaceae) growing in Kythira Island (Greece), and their antioxidant, antimicrobial, and antiproliferative properties

The Stachys L. genus has been used in traditional medicine to treat skin inflammations, stomach disorders, and stress. The aim of this study was to investigate the chemical profile and biological activity of the methanolic extract of Stachys spreitzenhoferi Heldr. (Lamiaceae) aerial parts, collected on the island of Kythira, South Greece. The analysis by liquid chromatography coupled with electrospray ionization and high-resolution mass spectrometry [LC-(-)ESI/HRMSⁿ] of the methanol extract revealed the occurrence of thirty-six compounds - flavonoids, phenylethanoid glycosides, iridoids, quinic acid derivatives, aliphatic alcohol glycosides, and oligosaccharides - highlighting the substantial presence, as main peaks, of the iridoid melittoside (2) along with flavonoid compounds such as 4'-O-methylisoscutellarein mono-acetyl-diglycoside/chrysoeriol mono-acetyl-diglycoside (24), trimethoxy- (35) and tetramethoxyflavones (36). This extract was tested for its antimicrobial properties against Gram-positive and negative pathogenic strains. The extract was not active against Gram-negative bacteria tested, but it possessed a good dose-dependent antimicrobial activity towards S. aureus (MIC: 1.0 mg/mL) and L. monocytogenes (MIC: 1.0 mg/mL) Gram-(+) strains. Furthermore, this extract has been tested for its possible antioxidant activity in vitro. In particular, it has been shown that these molecules cause a decrease in DPPH, ABTS, and H₂O₂ radicals. The extract of S. spreitzenhoferi exhibited anti-DPPH activity (IC₅₀: 0.17 mg/mL), anti-H₂O₂ activity (IC₅₀: 0.125 mg/mL), and promising antiradical effect with an IC₅₀ value of 0.18 mg/mL for anti-ABTS activity. S. spreitzenhoferi extract caused a decrease in ROS (at the concentration of 200 μg/mL) and an increase in the activity of the antioxidant enzymes SOD, CAT, and GPX in OZ-stimulated PMNs. Furthermore, it exhibited antiproliferative activity against acute myeloid leukemia (U937 cell), causing 50% of cell death at the 0.75 mg/mL.

Metabolite Profiling of “Green” Extracts of Cynara cardunculus subsp. scolymus, Cultivar “Carciofo di Paestum” PGI by 1H NMR and HRMS-Based Metabolomics

Globe artichoke (Cynara cardunculus L. var. scolymus L.), is a perennial plant widely cultivated in the Mediterranean area, known for its edible part named capitula or heads. Its functional properties are related to its high levels of polyphenolic compounds and inulin. “Carciofo di Paestum”, an Italian traditional cultivar, is a labeled PGI (Protected Geographical Indication) product of the Campania region, representing an important economic resource. So far, a few chemical investigations were performed on this cultivar, mainly focused on the analysis of methanol extracts. Due to the increasing use of food supplements, in this study, a comprehensive analysis of green extracts of “Carciofo di Paestum” PGI heads was performed. EtOH, EtOH: H₂O (80:20, 70:30, 60:40) extracts, as well as infusions and decoctions prepared according to Pharmacopeia XII were analyzed by LC-ESI/QExactive/MS/MS. A total of 17 compounds corresponding to caffeoylquinic acid derivatives, phenolics, flavonoids, and terpenoids were identified. The extracts were further submitted to NMR analysis to highlight the occurrence of primary metabolites. Both LCMS and NMR data were analyzed by Principal Component Analysis (PCA), showing significant differences among the extraction methods. Moreover, 5-caffeoylquinic acid and 1,5-dicaffeoylquinic acid were quantified in the extracts by LC-ESI/QTrap/MS/MS using the Multiple Reaction Monitoring (MRM) method. Furthermore, the phenolic content, antioxidant activity, and α-glucosidase inhibitory activity of C. cardunculus var. scolymus “Carciofo di Paestum” extracts were evaluated.

HR-LC-ESI-Orbitrap-MS-Based Metabolic Profiling Coupled with Chemometrics for the Discrimination of Different Echinops spinosus Organs and Evaluation of Their Antioxidant Activity

This study aimed to assess and correlate the phenolic content and the antioxidant activity of the methanol extracts of the stems, roots, flowers, and leaves of Echinops spinosus L. from north-eastern Algeria. Qualitative analysis was performed by high-resolution mass spectrometry (HR) LC-ESI-Orbitrap-MS and (HR) LC-ESI-Orbitrap-MS/MS). Forty-five compounds were identified in the methanol extracts; some are described for the first time in E. spinosus. Targeted phenolic compounds were quantified by HPLC-DAD and it was shown that caffeoyl quinic derivatives were the most abundant compounds. Chemometric analysis was performed using principal component analysis (PCA) and hierarchical cluster analysis (HCA) based on the qualitative and quantitative LC data. The score plot discriminates different Echinopsis spinosus organs into three distinct clusters, with the stems and flowers allocated in the same cluster, reflecting their resemblance in their secondary metabolites. The antioxidant activities of the methanol extracts were assessed using cupric reducing antioxidant capacity (CUPRAC), ferric reducing antioxidant assay (FRAP), diphenyl picryl hydrazyl radical-scavenging capacity assay (DPPH●), and 2,2’-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS●+). The root extract exhibited the highest antioxidant activity, evidenced by 3.26 and 1.61 mmol Fe2+/g dried residue for CUPRAC and FRAP, respectively, and great free radical-scavenging activities estimated by 0.53 and 0.82 mmol TEAC/g dried residue for DPPH● and ABTS●+, respectively. The methanol extract of the roots demonstrated a significant level of total phenolics (TP: 125.16 mg GAE/g dried residue) and flavonoids (TFI: 25.40 QE/g dried residue TFII: 140 CE/g dried residue). Molecular docking revealed that tricaffeoyl-altraric acid and dicaffeoyl-altraric acid exhibited the best fit within the active sites of NADPH oxidase (NO) and myeloperoxidase (MP). From ADME/TOPAKT analyses, it can be concluded that tricaffeoyl-altraric acid and dicaffeoyl-altraric acid also revealed reasonable pharmacokinetic and pharmacodynamic characteristics with a significant safety profile.

Corylus avellana: A Source of Diarylheptanoids With α-Glucosidase Inhibitory Activity Evaluated by in vitro and in silico Studies

Corylus avellana hard shells, green leafy involucres, leaves, and male flowers have shown to be a source of diarylheptanoids, a class of natural products with promising biological activities. Cyclic diarylheptanoids, named giffonins, were isolated from the Italian cultivar "Tonda di Giffoni." Even if many efforts have been made to establish the chemistry of these compounds, little is known about their biological properties. Herein, the inhibitory effects of diarylheptanoids isolated from C. avellana byproducts against α-glucosidase enzyme were evaluated. Molecular docking experiments disclosed the establishment of several key interactions between all the screened diarylheptanoids and the protein counterpart, whose model was built through homology modeling procedure, thus rationalizing the detected inhibitory activities. Specifically, the most active compounds giffonin J (10), K (11), and P (16) were able to make both H-bonds and π-π stacking contacts with different residues belonging to the binding site responsible for the catalytic activity of the investigated enzyme. To highlight the occurrence of the bioactive diarylheptanoids in the extracts of C. avellana byproducts obtained by eco-friendly extractions, their LC-MS profiles were analyzed. LC-MS analysis showed how giffonin J (10), K (11), and P (16) occurred in the ethanol extract of the leaves, while in the extracts of shells and green leafy involucres only giffonin P (16) was evident. Moreover, the quantitative analysis of giffonin J (10), K (11), and P (16) in C. avellana byproducts was carried out by an analytical approach based on LC-ESI/QTrap/MS, using the Multiple Reaction Monitoring (MRM) experiment. These results prompt to evaluate C. avellana byproducts, especially the leaves, as a prospective source of bioactive diarylheptanoids for the development of functional ingredients for the treatment of diabetes.

Mangostanin, a Xanthone Derived from Garcinia mangostana Fruit, Exerts Protective and Reparative Effects on Oxidative Damage in Human Keratinocytes

The fruit of Garcinia mangostana (mangosteen) is known in ancient traditional Asian medicine for its antioxidant, anti-inflammatory, immunomodulatory and anticancer activities. These effects are mainly due to the action of polyphenols known as xanthones, which are contained in the pericarp of the fruit. In recent years, there has been a growing interest from pharmaceutical companies in formulating new topicals based on mangosteen full extracts to prevent skin aging. However, the molecules responsible for these effects and the mechanisms involved have not been investigated so far. Here, the arils and shells of Garcinia mangostana were extracted with chloroform and methanol, and the extracts were further purified to yield 12 xanthone derivatives. Their effects were evaluated using in vitro cultures of human epidermal keratinocytes. After confirming the absence of cytotoxicity, we evaluated the antioxidant potential of these compounds, identifying mangostanin as capable of both protecting and restoring oxidative damage induced by H₂O₂. We showed how mangostanin, by reducing the generation of intracellular reactive oxygen species (ROS), prevents the activation of AKT (protein kinase B), ERK (extracellular signal-regulated kinase), p53, and other cellular pathways underlying cell damage and apoptosis activation. In conclusion, our study is the first to demonstrate that mangostanin is effective in protecting the skin from the action of free radicals, thus preventing skin aging, confirming a potential toward its development in the nutraceutical and cosmeceutical fields.

LC-ESI/HRMS analysis of glucosinolates, oxylipins and phenols in Italian rocket salad (Diplotaxis erucoides subsp. erucoides (L.) DC.) and evaluation of its healthy potential

BACKGROUND

This study investigated the chemical profile and biological activity of Diplotaxis erucoides subsp. erucoides (L.) DC. (Brassicaceae) collected in Sicily (Italy).

RESULTS

Liquid chromatography coupled with electrospray ionization and high-resolution mass spectrometry (LC-ESI/HRMS) analysis of the ethanol extract revealed the presence of 42 compounds - glucosinolates, hydroxycinnamic acids, flavonoids, and oxylipins. The extract was tested for its antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic) acid (ABTS), ferric reducing ability power (FRAP), and β-carotene bleaching tests. Promising protection from lipid peroxidation was observed after 30 min of incubation in a β-carotene bleaching test (IC₅₀ of 3.32 μg mL^-1 ). The inhibition of carbohydrates-hydrolyzing enzymes resulted in IC₅₀ values of 85.18 and 92.36 μg mL^-1 for α-amylase and α-glucosidase, respectively. Significant inhibition against lipase enzyme was observed (IC₅₀ of 61.27 μg mL^-1 ).

CONCLUSION

Diplotaxis erucoides can be considered a potential source of antioxidant, hypoglycemic, and hypolipidemic bioactives. © 2021 Society of Chemical Industry.

Metabolite Profiling of Helichrysum italicum Derived Food Supplements by 1H-NMR-Based Metabolomics

Helichrysum italicum is a medicinal plant from the Mediterranean area, widely used in traditional medicine for its anti-inflammatory, antibacterial and antioxidant properties and for its preventive effects on microcirculation diseases. Due to these properties, it finds large applications in cosmetic, food and pharmaceutical fields. Additionally, hydroalcoholic extracts and mother tinctures based on H. italicum represent products with a high commercial value, widely distributed not only in drug stores but also on on-line markets. The different extraction procedures used can greatly affect the fingerprints of the extracts, resulting in a different qualitative or quantitative profile of the chemical constituents responsible for biological activity. The aim of the present study was to characterize the composition of bioactive compounds present in water-ethanol and glycerol extracts of H. italicum derived food supplements. Metabolite profiles of the extracts were obtained by ¹H NMR experiments and data were processed by multivariate statistical analysis to highlight differences in the extracts and to evidence the extracts with the highest concentrations of bioactive metabolites. In detail, this work highlights how derived food supplements of H. italicum obtained using ethanol-water mixtures ranging from 45% to 20% of ethanol represent the products with the highest amount of both primary (amino acids) and secondary metabolites including 3,4-dicaffeoylquinic acid (9), chlorogenic acid (10), 3,5-dicaffeoylquinic acid (11), and kaempferol 3-O-glucopyranoside (12). Moreover, it is evident that the use of an ethanol-water mixture 20:80 is the most suitable method to afford the highest number of phenolic compounds, while food-derived supplements obtained by glycerol extraction are characterized by a high amount of β-glucose and α-glucose and a low content of phenolic compounds.

Conversion of Organic Dyes into Pigments: Extraction of Flavonoids from Blackberries (Rubus ulmifolius) and Stabilization

The blackberry’s color is composed mainly of natural dyes called anthocyanins. Their color is red–purple, and they can be used as a natural colorant. Anthocyanins are flavonoids, which are products of plants, and their colors range from orange and red to various shades of blue, purple and green, according to pH. In this study, the chemical composition of an extract obtained from blackberries was defined by LC-ESI/LTQOrbitrap/MS in positive and negative ionization mode. Furthermore, we investigated the adsorption process of blackberry extract using several inorganic fillers, such as metakaolin, silica, Lipari pumice, white pozzolan and alumina. The pigments exhibit different colors as a function of their interactions with the fillers. The analysis of the absorption data allowed the estimation of the maximum adsorbing capacity of each individual filler tested. Through thermogravimetric measurements (TGA), the thermal stability and the real adsorption of the organic extract were determined.

LC-ESI/LTQOrbitrap/MS Metabolomic Analysis of Fennel Waste (Foeniculum vulgare Mill.) as a Byproduct Rich in Bioactive Compounds

Food industries produce a high amount of waste every year. These wastes represent a source of bioactive compounds to be used to produce cosmetic and nutraceutical products. In this study, the possibility to retrain food waste as a potential source of bioactive metabolites is evaluated. In particular, metabolite profiles of different parts (bulb, leaves, stems and little stems) of fennel waste were investigated by liquid chromatography coupled with mass spectrometry (LC-ESI/LTQ Orbitrap MS). To discriminate the different plant parts, a Multivariate Data Analysis approach was developed. Metabolomic analysis allowed the identification of different metabolites mainly belonging to hydroxycinnamic acid derivatives, flavonoid glycosides, flavonoid aglycons, phenolic acids, iridoid derivatives and lignans. The identification of compounds was based on retention times, accurate mass measurements, MS/MS data, exploration on specific metabolites database and comparison with data reported in the literature for F. vulgare. Moreover, the presence of different oxylipins was relieved; these metabolites for the first time were identified in fennel. Most of the metabolites identified in F. vulgare possess anti-inflammatory, antioxidant and/or immunomodulatory properties. Considering that polyphenols are described to possess antioxidant activity, spectrophotometric tests were performed to evaluate the antioxidant activity of each part of the fennel.

Metabolite Profile and In Vitro Beneficial Effects of Black Garlic (Allium sativum L.) Polar Extract

Over the centuries, humans have traditionally used garlic (Allium sativum L.) as a food ingredient (spice) and remedy for many diseases. To confirm this, many extensive studies recognized the therapeutic effects of garlic bulbs. More recently, black garlic (BG), made by heat-ageing white garlic bulbs, has increased its popularity in cuisine and traditional medicine around the world, but there is still limited information on its composition and potential beneficial effects. In this study, the metabolite profile of methanol extract of BG (BGE) was determined by high-performance liquid chromatography coupled to tandem mass spectrometry in high-resolution mode. Results allowed to establish that BGE major components were sulfur derivatives, saccharides, peptides, organic acids, a phenylpropanoid derivative, saponins, and compounds typical of glycerophospholipid metabolism. Characterization of the BGE action in cancer cells revealed that antioxidant, metabolic, and hepatoprotective effects occur upon treatment as well as induction of maturation of acute myeloid leukemia cells. These results are interesting from the impact point of view of BG consumption as a functional food for potential prevention of metabolic and tumor diseases.

Almond (Prunus dulcis cv. Casteltermini) Skin Confectionery By-Products: New Opportunity for the Development of a Functional Blackberry (Rubus ulmifolius Schott) Jam

This work proposes for the first time a model for reusing almond (Prunus dulcis cv. Casteltermini from Sicily, Southern Italy) skin to formulate a new functional blackberry (Rubus ulmifolius Schott) jam. For this purpose, blackberries were analysed fresh and as jam, traditionally prepared with a minimum fruit amount of 80%. Different percentages of almond skin (20, 15, and 10% w/w) were added to jam. The phytochemical profile of enriched jam was investigated by LC-ESI/LTQOrbitrap/MS analyses. Anthocyanins, hydrolysable tannins, and triterpenoids were identified in a blackberry extract, while proanthocyanidins, flavonoids, and oxylipins were identified in an almond extract. The n-hexane extract of P. dulcis skin, investigated by GC-MS, evidenced linoleic, palmitic, and oleic acids as the main abundant compounds. Samples were investigated for their antioxidant activity using DPPH, ABTS, β-carotene, and FRAP tests. The hypoglycaemic and hypolipidemic effects were studied by α-amylase, α-glucosidase, and lipase inhibitory assays. In order to evaluate the effect of thermal process on enriched jam bioactivity, pasteurisation was applied. An increase in activities for all samples was observed, in particular for jam enriched with 20% w/w of almond skin. Based on obtained data, and supported by sensory analysis, we propose enriched jam as a promising source of compounds useful for preventing diseases associated with oxidative stress.

Okra fruit: LC-ESI/LTQOrbitrap/MS/MSn based deep insight on polar lipids and specialized metabolites with evaluation of anti-oxidant and anti-hyperglycemic activity

Okra is a vegetable crop very popular in tropical, subtropical, and warm temperate regions of the world for its edible fruit. Nowadays, this species can be easily found in European local markets, as a basic ingredient in many local and traditional dishes. Considering the extensive and spread use of okra fruits, to achieve deep insight on its chemical composition the analysis of the polar extract by high-performance liquid chromatography coupled to multiple-stage linear ion-trap and orbitrap high-resolution mass spectrometry in negative electrospray ionization mode was carried out. By this approach, 39 metabolites belonging to different polar lipid classes, such as oxylipins, phospholipids, glycolipids, and sphingolipids, were putatively identified for the first time in A. esculentus. Moreover, LC-HRMS/MS analyses guided the isolation and characterization by NMR experiments of 19 specialized metabolites belonging to phenolic acid and flavonoid classes, 8 of them never reported before in A. esculentus. Finally, antioxidant activity and inhibition of α-glucosidase activity were assayed, suggesting a good anti-oxidant anti-hyperglycemic activity for okra fruit.

Giffonins, Antioxidant Diarylheptanoids from Corylus avellana, and Their Ability to Prevent Oxidative Changes in Human Plasma Proteins

With the aim to explore the ability of diarylheptanoids to reduce oxidative changes in human plasma proteins, a phytochemical investigation of the MeOH extract of Corylus avellana leaves was perfomed. Analysis by LC-ESI/LTQOrbitrap/MS/MSⁿ guided the isolation of two new diarylheptanoid derivatives, giffonins W (1) and X (2). The structures 1 and 2 were assigned by analysis of NMR data combined with a QM (quantum mechanical)/NMR approach. The absolute configurations of 1 and 2 were established by analysis of electronic circular dichroism (ECD) spectra compared with the TDDFT-simulated curves. The antioxidant activity of the new and known giffonins was evaluated by inhibition of human plasma lipid peroxidation. Giffonins with the highest inhibitory activity were tested for their ability to reduce oxidation of thiol groups and carbonylation in plasma proteins, and some of them exhibited higher antioxidant activity than curcumin.

Effects of bio-fertilizers on the production of specialized metabolites in Salvia officinalis L. leaves: An analytical approach based on LC-ESI/LTQ-Orbitrap/MS and multivariate data analysis

In recent years, the use of organic substances has been increased to improve the production of specialized metabolites in aromatic and medicinal plants. Salvia officinalis L., known as sage, is an important medicinal and aromatic plant, whose leaves are commonly used as a condiment in food but mainly as a raw material in pharmaceutical and perfumery industries. In this work to define the effects of bio-fertilizers and foliar applications of l-phenylalanine on specialized metabolites production and biochemical characteristics of S. officinalis leaves, an experimental field in 2 years (2016 and 2017) was developed in semiarid climate, South-western, Iran. Experimental treatments included foliar spraying of l-phenylalanine in diverse concentration (0-250 and 500 mg/mL) and different bio-fertilizers [Arbuscular mycorrhizal fungi (AMF), Pseudomonas fluorescens (Pf), both fungi and bacteria (AMF + Pf)]. A metabolomics approach was carried out on the ethanolic extracts of sage leaves obtained by different treatments using Liquid Chromatography coupled with High-Resolution Mass Spectrometry (LC-ESI/LTQ-Orbitrap/MS) followed by multivariate data analysis. A total of 41 specialized metabolites were detected, and 35 of them were identified based on their accurate mass and mass fragmentation, as belonging to organic acids, phenylpropanoids, flavonoids, diterpenes, salvianolic acids and oxylipins. This work highlighted that the foliar application of l-phenylalanine along with the inoculation of Arbuscular mycorrhizal fungi and P. fluorescens can improve the yields of specific metabolites of pharmaceutical interest.

Terpenoid Constituents of Perovskia artemisioides Aerial Parts with Inhibitory Effects on Bacterial Biofilm Growth

Perovskia artemisioides is a perennial and aromatic plant distributed in the Baluchestan region of Iran. In the present work, an n-hexane extract of P. artemisioides aerial parts showed excellent capabilities to both inhibit the formation of biofilms by different Gram-positive and Gram-negative pathogens and block the cell metabolism within microbial biofilms. To correlate the activity of the extract with the biologically active compounds present, first an analytical approach based on LC-HRMS/MSⁿ was carried out. The metabolite profile obtained guided the isolation of 21 compounds, among which two sesquiterpenes (8 and 9) and one diterpene (10) were found to be new. The antimicrobial activity of the isolated compounds was evaluated by determining how they were able not only to reduce the growth of different Gram-positive and Gram-negative human bacteria and phytopathogens but also to inhibit the formation of biofilms by these bacteria and affect the metabolism of microbial cells present within the biofilms. With the aim of correlating the activity exhibited by the extract with the concentration levels of the constituent compounds, a quantitative determination was carried out by an analytical approach based on LC-ESI/QTrap/MS.

Triterpene glycosides from Silene odontopetala

Silene species are known for their use in traditional medicine in treating several diseases. To the authors' knowledge there is no report on the chemical composition of S. odontopetala. Therefore, the phytochemical investigation of the methanol extract of S. odontopetala was carried out, leading to the isolation of six undescribed oleanane-type glycosides along with the known saponin azukisaponin IV. Their structures were elucidated by the analysis of 1D and 2D-NMR experiments, along with mass spectrometry analysis. The cytotoxic activity of oleanane-type saponins was evaluated against a small panel of cancer cell lines, including PC-3 (prostate carcinoma cells), MCF-7 (breast cancer cells), A549 (alveolar basal carcinoma cells), and HeLa (cervical carcinoma cells). Furthermore, the activity of isolated compounds against a normal cell line HEK-293, used for assessing their cytotoxicity, was evaluated.

Chemical profiling and biological screening with potential anti-inflammatory activity of Callisia fragrans grown in Egypt

The ethanolic extract of Callisia fragrans aerial parts showed a significant strong in vivo anti-inflammatory and in vitro antioxidant activities with a high in vivo gastrointestinal safety profile and a very low in vitro cytotoxicity on peripheral blood mononuclear cells (PBMCs) with an IC₅₀ > 1000 μg/ml. The alcoholic extract of C. fragrans has been analysed by HPLC coupled to multiple-stage Linear Ion-Trap and Orbitrap High-Resolution mass spectrometry in negative electrospray ionisation mode (LC-ESI/LTQOrbitrap/MS/MSn). By this approach, it was possible to putatively identify 13 compounds, mainly organic acids, flavonoids, one steroid and one hydroxy-coumarin. Luteolin 6-C-glucopyranosyl-7-O-glucopyranoside, luteolin-8-C-glucopyranosyl-7-O-rhamnopyranoside, luteolin-6-C-glucoside and isoorientin 7-O-[6''-feruloyl]-glucoside were detected for the first time in C. fragrans and family Commelinaceae.

Cardenolide-rich fraction of Pergularia tomentosa as a novel Antiangiogenic agent mainly targeting endothelial cell migration

PURPOSE

Angiogenesis related abnormalities underlie several life-threatening disorders. Despite approved therapies, scientists have yet to develop highly efficient, low cost approaches with minimal side effects.

METHODS

We evaluated the antiangiogenic activity of 50% hydroalcoholic extracts of Pergularia tomentosa L. root and aerial parts along with their EtOAc and water fractions, in vivo and in vitro. Transgenic zebrafish line Tg(fli1:EGFP) was used for in vivo assay and human umbilical vein endothelial cell (HUVEC) migration test along with possibility of tube formation were performed as in vitro tests. Furthermore, microvasculature in chicken chorioallantoic membrane (CAM) was assessed under P. tomentosa treatment. The fractionation of the 50% hydroalcoholic extracts was led to the identification of the best active fraction in this study. The metabolite profiling of the active fraction was also carried out using LC-HRESIMS analysis.

RESULTS

Pergularia tomentosa markedly inhibited intersegmental vessel (ISV) formation at 48 h post-fertilization (hpf) embryos in zebrafish. The water fraction of root hydroalcoholic extract (PtR2), showed strong antiangiogenic effect with minimal adverse viability impacts. Over 80% of embryos showed more than 50% inhibition in their ISV development at 20 and 40 μg/mL. PtR2 at 20 μg/mL substantially reduced human umbilical vein endothelial cell (HUVEC) migration up to 40%, considerable destruction of the formed tubes in the tube formation and microvasculature in CAM assays. Immunocytochemistry showed a marked reduction in vascular endothelial cadherin (VE-cadherin) abundance at cell junctions concurrent with substantial reduction of phospho-Akt (p-Akt) and β-catenin protein expressions. Phytochemical profile of PtR2 showed a rich source of cardenolide structures, including ghalakinoside, calactin and calotropin derivatives.

CONCLUSION

Thus, the P. tomentosa cardenolide-rich fraction (PtR2) may hold a considerable promise for an antiangiogenic impact by impairment of endothelial cell (EC) migration and viability. Graphical abstract.

Phytochemical investigation of Scabiosa sicula guided by a preliminary HPLC-ESIMSn profiling

The genus Scabiosa (Caprifoliaceae) is represented by 80 species, widely used as medicinal plants for their positive effects on human diseases. On the basis of the interesting biological activity shown by Scabiosa spp., the phytochemical investigation of Scabiosa sicula L., never investigated before, was carried out. An initial LC-MS profile of the MeOH extract of S. sicula whole plant guided the isolation of 34 compounds, of which the structures were unambiguously elucidated by NMR analysis as phenolic compounds and triterpene saponins, among which eight undescribed compounds. Moreover, the total phenolic content of S. sicula methanol extract has been evaluated. On the basis of the pharmacological activities reported for Scabiosa species the antioxidant activity of the methanol extract was tested by TEAC and DPPH assays. Finally, the α-glucosidase inhibitory activity of the methanol extract was assayed, showing an IC₅₀ value (49 μg/mL) comparable to that exerted by acarbose (90 μg/mL), used as positive control.

Comparative Phytochemical Characterization, Genetic Profile, and Antiproliferative Activity of Polyphenol-Rich Extracts from Pigmented Tubers of Different Solanum tuberosum Varieties

Plants produce a vast array of biomolecules with beneficial effects for human health. In this study, polyphenol and anthocyanin-rich extracts (PAE) from pigmented tubers of Solanum tuberosum L. varieties “Blue Star”, “Magenta Love”, and “Double Fun” in comparison with the more extensively studied “Vitelotte” were evaluated and compared for antiproliferative effects in human leukemia cells, and their phytochemical and genetic profiles were determined. In U937 cells, upon treatment with PAE, it was possible to reveal the expression of specific apoptotic players, such as caspase 8, 9, 3, and poly (ADP-ribose) polymerase (PARP), as well as the induction of monocyte and granulocyte differentiation. A liquid chromatography/electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) investigation revealed the presence of polyphenolic compounds in all the varieties of potatoes analyzed, among which caffeoyl and feruloyl quinic acid derivatives were the most abundant, as well as several acylated anthocyanins. Each pigmented variety was genotyped by DNA-based molecular markers, and flavonoid-related transcription factors were profiled in tubers in order to better characterize these outstanding resources and contribute to their exploitation in breeding. Interesting biological activities were observed for “Blue Star” and “Vitelotte” varieties with respect to the minor or no effect of the “Double Fun” variety.

Detection and comparison of phenolic compounds in different extracts of black currant leaves by liquid chromatography coupled with high-resolution ESI-LTQ-Orbitrap MS and high-sensitivity ESI-Qtrap MS

Liquid preparations such as tinctures and infusion derived from Ribes nigrum L. (black currant) leaves are widely used in Europe. Despite the various uses reported for the infusion and hydroalcoholic extracts of the leaves of this species, their chemical profile has not yet been defined. In the present study, the infusion, hydroalcholic and methanolic extracts prepared from R. nigrum leaves were analyzed. LC-MS analyses of these extracts allowed the characterization of 31 phenolic compounds mainly belonging to organic acids, flavonoids, catechins and its oligomers. Quantitative results proved that these preparations are a rich source of polyphenols and flavonoids and among them the infusion presented the highest polyphenol levels. A metabolomics approach was also used for the comparison and evaluation of the chemical composition of the different extracts obtained from R. nigrum leaves.

Garcinol and Related Polyisoprenylated Benzophenones as Topoisomerase II Inhibitors: Biochemical and Molecular Modeling Studies

Garcinol, a polyisoprenylated benzophenone isolated from Garcinia genus, has been reported to inhibit eukaryotic topoisomerase I and topoisomerase II at concentrations comparable to that of etoposide (∼25-100 μM). With the aim to clarify the underlying molecular mechanisms by which garcinol inhibits human topoisomerase IIα and topoisomerase IIβ, biochemical assays along with molecular docking and molecular dynamics studies were carried out on garcinol and six congeners. The biochemical results revealed that garcinol derivatives appear to act as catalytic inhibitors of topoisomerase II and to inhibit ATP hydrolysis by topoisomerase II via some form of mixed inhibition. The computational investigation identified the structural elements responsible for binding to the biological target and also provided information for the eventual design of more selective and potent analogues. Collectively, our data suggest that garcinol-type agents may bind to the DNA binding surface and/or ATP domain of type II topoisomerases to antagonize function.

Cytotoxicity of cucurbitacin E from Citrullus colocynthis against multidrug-resistant cancer cells

BACKGROUND

Cucurbitacin E (CuE) is an oxygenated tetracyclic triterpenoid isolated from the fruits of Citrullus colocynthis (L.) Schrad.

PURPOSE

This study outlines CuE's cytotoxic activity against drug-resistant tumor cell lines. Three members of ABC transporters superfamily, P-glycoprotein (P-gp), breast cancer resistance protein (BCRP) and ABCB5 were investigated, whose overexpression in tumors is tightly linked to multidrug resistance. Further factors of drug resistance studied were the tumor suppressor TP53 and the epidermal growth factor receptor (EGFR).

METHODS

Cytotoxicity assays (resazurin assays) were used to investigate the activity of Citrullus colocynthis and CuE towards multidrug resistant cancer cells. Molecular docking (In silico) has been carried out to explore the CuE's mode of binding to ABC transporters (P-gp, BCRP and ABCB5). The visualization of doxorubicin uptake was done by a Spinning Disc Confocal Microscope. The assessment of proteins expression was done by western blotting analysis. COMPARE and hierarchical cluster analyses were applied to identify, which genes correlate with sensitivity or resistance to cucurbitacins (CuA, CuB, CuE, CuD, CuI, and CuK).

RESULTS

Multidrug-resistant cells overexpressing P-gp or BCRP were cross-resistant to CuE. By contrast, TP53 knock-out cells were sensitive to CuE. Remarkably, resistant cells transfected with oncogenic ΔEGFR or ABCB5 were hypersensitive (collateral sensitive) to CuE. In silico analyses demonstrated that CuE is a substrate for P-gp and BCRP. Immunoblot analyses highlighted that CuE targeted EGFR and silenced its downstream signaling cascades. The most striking result that emerged from the doxorubicin uptake by ABCB5 overexpressing cells is that CuE is an effective inhibitor for ABCB5 transporter when compared with verapamil. The COMPARE analyses of transcriptome-wide expression profiles of tumor cell lines of the NCI identified common genes involved in cell cycle regulation, cellular adhesion and intracellular communication for different cucurbitacins.

CONCLUSION

CuE represents a potential therapeutic candidate for the treatment of certain types of refractory tumors. To best of our knowledge, this is the first time to identify CuE and verapamil as inhibitors for ABCB5 transporter.

Plant Specialized Metabolites in Hazelnut (Corylus avellana) Kernel and Byproducts: An Update on Chemistry, Biological Activity, and Analytical Aspects

Corylus avellana (hazelnut) is one of the most popular tree nuts on a worldwide basis. The main products of C. avellana are kernels, a nutritious food, with a high content of healthy lipids, contained in a hard shell. In recent years, along with the ongoing research carried out on hazelnut kernels, a growing interest has been addressed to the hazelnut byproducts including hazelnut skin, hazelnut hard shell, and hazelnut green leafy cover as well as hazelnut tree leaf. These byproducts deriving from the roasting, cracking, shelling/hulling, and harvesting processes have been found as a source of "phytochemicals" with biological activity. The aim of this review is to provide a comprehensive and critical update on the chemistry and biological activity of specialized metabolites occurring in hazelnut kernels and byproducts. Phenolics are the most abundant phytochemicals not only in the kernels, but also in other processing byproducts. Attention has been also devoted to taxane derivatives isolated from C. avellana leaves. An overview on the biological activity, mainly antioxidant, antiproliferative, and antimicrobial along with less common biological effects, has been provided, contributing to highlight C. avellana as a source of bioactive phytochemicals with the potential to exert beneficial effects on human health. Finally, analytical techniques for the quali-quantitative analysis of specialized metabolites occurring in the different parts of C. avellana have been reviewed.

HR-LC-ESI-Orbitrap-MS based metabolite profiling of Prunus dulcis Mill. (Italian cultivars Toritto and Avola) husks and evaluation of antioxidant activity

INTRODUCTION

Prunus dulcis Mill. is a plant cultivated for the production of its edible seeds, known as sweet almonds. In the last decades almond demand has highly increased due to their wide use in the industrial manufacturing of almond-based foods; this has led to a huge production of waste materials, mainly corresponding to shells and husks.

OBJECTIVE

To achieve a deeper understanding of the chemical composition of almond husks with the aim of exploring these byproducts as a source of bioactives to be used in nutraceutical and cosmetic formulations.

METHODS

Methanol, ethanol and ethanol-water extracts of the almond husks were analysed by high-resolution liquid chromatography electrospray ionisation Orbitrap mass spectrometry (HR-LC-ESI-Orbitrap-MS) in negative ion mode. Tandem mass spectrometry (MS/MS) data were acquired by using the Data-Dependent Scan experiment, allowing the precursor ion to be selected as the most intense peak during LC-MS analyses. Nuclear magnetic resonance (NMR) experiments were performed on a Bruker DRX-600 spectrometer. Folin-Ciocalteu, DPPH^• (2,2-diphenyl-1-picrylhydrazyl) and TEAC (Trolox equivalent antioxidant capacity) assays were employed to determine the total phenolic content and the radical scavenging activity of the extracts.

RESULTS

The LC-MS/MS analysis of the methanol extract guided the isolation of phloroglucinol derivatives, flavonoids and terpenes. Eco-friendly extraction methods showed to be selective in extracting flavonoids while the comparison of the LC-MS profiles of the Italian cultivars Toritto and Avola showed significant differences, confirming how different growing conditions may influence the metabolome of a plant species.

CONCLUSION

This study led to a deeper insight into the chemical constituents of almond husks and showed how the eco-friendly extraction resulted in an effective method to obtain extracts rich in antioxidant sources.

A Symphytum officinale Root Extract Exerts Anti-inflammatory Properties by Affecting Two Distinct Steps of NF-κB Signaling

Symphytum officinale, commonly known as comfrey, constitutes a traditional medicinal plant with a long-standing therapeutic history, and preparations thereof have been widely used for the treatment of painful muscle and joint complaints, wound and bone healing, and inflammation. Today, its topical use is based on its analgesic and anti-inflammatory effects, which have been substantiated by modern clinical trials. However, the molecular basis of its action remained elusive. Here, we show that a hydroalcoholic extract of comfrey root impairs the development of a pro-inflammatory scenario in primary human endothelial cells in a dose-dependent manner. The extract, and especially its mucilage-depleted fraction, impair the interleukin-1 (IL-1) induced expression of pro-inflammatory markers including E-selectin, VCAM1, ICAM1, and COX-2. Both preparations inhibit the activation of NF-κB, a transcription factor of central importance for the expression of these and other pro-inflammatory genes. Furthermore, our biochemical studies provide evidence that comfrey inhibits NF-κB signaling at two stages: it dampens not only the activation of IKK1/2 and the subsequent IκBα degradation, but also interferes with NF-κB p65 nucleo-cytoplasmatic shuttling and transactivation. These results provide a first mechanistic insight into the mode of action of a century-old popular herbal medicine.

Triterpenes from Maytenus macrocarpa and Evaluation of Their Anti-HIV Activity

A set of pentacyclic triterpenes has been isolated from the bark of Maytenus macrocarpa (Celastraceae). It includes two new olean-12-ene derivatives, namely 3β, 22α-dihydroxy-olean-12-en-30-oic acid (1) and 22α-hydroxy-olean-12-en-3-oxo-30-oic acid (2), and the new urs-12-ene derivative 3-(E)-coumaroyluvaol (7), along with 10 known compounds possessing olean-12-ene, urs-12-ene, lupane and friedelane skeletons. The structures have been elucidated by extensive spectroscopic methods including 1D- and 2D-NMR experiments, as well as ESI-MS analysis. All isolated compounds were tested for anti-HIV activity in C8166 cells infected with HIV-1MN. The most active compound was 22α-hydroxy-12-en-3-oxo-29-oic acid (triterpenonic acid A, 4), with an EC50 value of 1 μg/mL and a selectivity index of 35.