Yunnaneic Acid B, a Component of Pulmonaria officinalis Extract, Prevents Peroxynitrite-Induced Oxidative Stress in Vitro

Anti-inflammatory and antioxidant actions of extracts from Rheum rhaponticum and Rheum rhabarbarum in human blood plasma and cells in vitro

Rheum rhaponticum L. (rhapontic rhubarb) and Rheum rhabarbarum L. (garden rhubarb) are edible and medicinal rhubarb species used for many centuries in traditional medicine. This work is focused on the biological activity of extracts from petioles and roots of R. rhaponticum and R. rhabarbarum as well as rhapontigenin and rhaponticin, typical stilbenes present in these rhubarbs, in a context of their effects on blood physiology and cardiovascular health. Anti-inflammatory properties of the examined substances were evaluated in human peripheral blood mononuclear cells (PBMCs) and THP1-ASC-GFP inflammasome reporter cells. Due to the coexistence of inflammation and oxidative stress in cardiovascular diseases, the study design included also antioxidant assays. This part of the work involved the assessment of the protective efficiency of the examined substances against the peroxynitrite-triggered damage to human blood plasma components, including fibrinogen, a protein of critical importance for blood clotting and maintaining the haemostatic balance. Pre-incubation of PBMCs with the examined substances (1-50 μg/mL) considerably decreased the synthesis of prostaglandin E2 as well as the release of pro-inflammatory cytokines (IL-2 and TNF-α) and metalloproteinase-9. A reduced level of secreted apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) specks in the THP-1-ASC-GFP cells was also observed. The examined substances significantly diminished the extent of ONOO‾induced oxidative modifications of blood plasma proteins and lipids and normalized, or even strengthened blood plasma antioxidant capacity. Furthermore, a reduction of oxidative damage to fibrinogen, including modifications of tyrosine and tryptophan residues along with the formation of protein aggregates was found.

Biological Activities and Phytochemicals of Lungworts (Genus Pulmonaria) Focusing on Pulmonaria officinalis

Lungworts (members of genus Pulmonaria), especially Pulmonaria officinalis, have been used as medicinal plants in folk and traditional medicine. The potential biological activities of lungworts, such as antioxidant, anti-inflammatory, anti-neurodegenerative, skin whitening, anticoagulant, antibacterial, anti-anemic, anticonvulsant, and wound-healing properties, have been observed in different studies. More than 90 phytochemicals belonging to pharmacologically active phytochemical classes have been reported for lungworts, which can be considered as one of the important contributors to the biological properties along with micronutrients. However, safety studies and clinical trials are missing for lungworts to establish most of their potential biological properties. Similarly, in vivo studies are lacking for anti-inflammatory and anti-neurodegenerative disorders and more in vivo studies are required to strengthen the knowledge of their antioxidant, anticoagulant, and anti-convulsant properties. A comprehensive compilation of the phytochemicals and biological properties of lungworts is also lacking in the literature, which can provide future direction for further pharmacological research. Hence, an attempt has been made in this study to compile the phytochemicals and biological properties to not only provide the resources for the design of further research to develop the pharmacological application of lungworts, but also to highlight the gaps and provide suggestions for future development.

Comparison of Phenolic Metabolites in Purified Extracts of Three Wild-Growing Herniaria L. Species and Their Antioxidant and Anti-Inflammatory Activities In Vitro

The work is aimed at phytochemical characterization and In Vitro evaluation of antioxidant actions, anti-inflammatory effects, and cytotoxicity of purified extracts from three rupturewort (Herniaria L.) species, i.e., Herniaria glabra (HG), H. polygama (HP), and H. incana herb (HIh). The total phenolic content established in the purified extracts (PEs) of HIh, HP, and HG was 29.6, 24.0, and 13.0%, respectively. Thirty-eight non-saponin metabolites were identified using LC-HR-QTOF-ESI-MS; however, only 9 were common for the studied Herniaria species. The most abundant phenolic compound in HG-PE was narcissin (7.4%), HP-PE shared 3 major constituents, namely cis-2-hydroxy-4-methoxycinnamic acid 2-O-β-glucoside (cis-GMCA, 5.8%), narcissin (5.4%), and rutin (5.3%). Almost half of HIh phenolic content (14.7%) belonged to oxytroflavoside A (7-O-methylkaempferol-3-O-[3-hydroxy-3-methylglutaryl-(1→6)]-[α-rhamnopyranosyl-(1→2)]-β-galactopyranoside). Antioxidant properties of the Herniaria PEs were evaluated employing an experimental model of human blood plasma, exposed to the peroxynitrite-induced oxidative stress. The assays demonstrated significant reduction of oxidative damage to protein and lipid plasma components (estimated by measurements of 3-nitrotyrosine, protein thiol groups, thiobarbituric acid-reactive substances), and moderate protection of its non-enzymatic antioxidant capacity. Anti-inflammatory properties of the Herniaria PEs were evaluated In Vitro as inhibitory effects against cyclooxygenases (COX-1 and -2) and concanavalin A-induced inflammatory response of the peripheral blood mononuclear cells (PBMCs). None of the studied plants showed inhibitory effects on COXs but all purified extracts partly reduced the release of interleukin 2 (IL-2) and tumor necrosis factor-alpha (TNF-α) from PBMCs, which suggested their prospective ability to up-regulate inflammatory response of the cells. The purified extract from H. glabra turned out to be the most efficient suppressor of PBMCs’ inflammatory response. Additionally, cytotoxicity of purified Herniaria extracts on PBMCs was ruled out based on In Vitro studies.

Potential Activity Mechanisms of Aesculus hippocastanum Bark: Antioxidant Effects in Chemical and Biological In Vitro Models

The bark of Aesculus hippocastanum is an herbal remedy used in conditions connected with vascular insufficiency; however, there is a lack of data concerning its mechanisms of action. The present work is a preliminary investigation into some of the potential directions of the bark activity. The phytochemically (qualitative UHPLC-PDA-MS/MS and quantitative UHPLC-PDA assays) characterized extract and its four main constituents (esculin, fraxin, (‒)-epicatechin and procyanidin A2) were first evaluated in terms of their antioxidant capacity. All analytes demonstrated dose-dependent scavenging potential towards the most common in vivo oxidants, with particularly advantageous capacity of the extract and its flavan-3-ol constituents against peroxynitrite (3.37–13.26 mmol AA/g), hydroxyl radical (5.03–8.91 mmol AA/g) and superoxide radical (3.50–5.50 mmol AA/g). Moreover, even at low concentrations (1–5 µg/mL), they protected components of human plasma against oxidative damage inflicted by peroxynitrite, preventing oxidation of plasma protein thiols and diminishing the tyrosine nitration and lipid peroxidation. High efficiency of the analytes was also demonstrated in preventing the peroxynitrite-induced nitrative changes of fibrinogen (up to 80% inhibition for (‒)-epicatechin at 50 µg/mL), an important protein of coagulation cascade. Additionally, the extract and its constituents had, at most, moderate inhibitory activity towards platelet aggregation induced by ADP and only negligible influence on clotting times. The results show that, among the investigated properties, the antioxidant activity might, to the highest extent, be responsible for the bark efficacy in vascular disorders, thus supporting its application in those conditions; they also indicate the directions for future research that would allow for better understanding of the bark activity.

Phenolic profile, safety assessment, and anti-inflammatory activity of Salvia verbenaca L

ETHNOPHARMACOLOGICAL RELEVANCE

Salvia species are known to have anti-inflammatory properties, and are traditionally used for healing purposes. Salvia verbenaca is an Algerian plant used for healing wounds and ulcers.

AIM OF THE STUDY

This work aims to assess the acute and subacute safety of S. verbenaca and its possible anti-inflammatory activity as a mechanism contributing to its traditional applications.

MATERIALS AND METHODS

Lethal toxicity of S. verbenaca hydromethanolic extract was evaluated against Artemia salina larvae, while acute and subacute toxicity were orally tested on mice. The anti-inflammatory activity was screened ex vivo using membrane stabilization and in vivo using xylene induced ear edema as an acute inflammation model. The antiradical, reducing power and iron chelating activities of S. verbenaca were also investigated in vitro, and phenolic compounds were determined using UHPLC-DAD-ESI-MSⁿ_. RESULTS: Salvia verbenaca extract contained high amounts of phenolic compounds (206 μg GAE/mg extract). The in vitro antioxidant activity showed promising radical scavenging ability, iron chelating (IC₅₀: 189 μg/mL), reducing power and strong anti-lipid-peroxidation effect (IC₅₀: 111 μg/mL). The extract had potential cytotoxic effect against Artemia salina larvae (LC₅₀: 30 μg/mL), but did not exhibit any acute/subacute toxicity effect on mice. Salvia verbenaca inhibited hypotonic and heat induced hemolysis and also reduced 50% of xylene induced ear edema at 600 mg/kg bw. Rosmarinic acid and caffeoylmalic acid were identified as the major compounds.

CONCLUSION

Salvia verbenaca hydromethanolic extract was found to be safe at acute and subacute levels. Its in vitro/in vivo antioxidant activity, membrane stabilizing properties and anti-inflammatory activity may be an important aspect of its wound healing and anti-ulcer traditional use.

Pulmonaria obscura and Pulmonaria officinalis Extracts as Mitigators of Peroxynitrite-Induced Oxidative Stress and Cyclooxygenase-2 Inhibitors-In Vitro and In Silico Studies

The Pulmonaria species (lungwort) are edible plants and traditional remedies for different disorders of the respiratory system. Our work covers a comparative study on biological actions in human blood plasma and cyclooxygenase-2 (COX-2) -inhibitory properties of plant extracts (i.e., phenolic-rich fractions) originated from aerial parts of P. obscura Dumort. and P. officinalis L. Phytochemical profiling demonstrated the abundance of phenolic acids and their derivatives (over 80% of the isolated fractions). Danshensu conjugates with caffeic acid, i.e., rosmarinic, lithospermic, salvianolic, monardic, shimobashiric and yunnaneic acids were identified as predominant components. The examined extracts (1–100 µg/mL) partly prevented harmful effects of the peroxynitrite-induced oxidative stress in blood plasma (decreased oxidative damage to blood plasma components and improved its non-enzymatic antioxidant capacity). The cellular safety of the extracts was confirmed in experimental models of blood platelets and peripheral blood mononuclear cells. COX-2 inhibitor screening evidently suggested a stronger activity of P. officinalis (IC₅₀ of 13.28 and 7.24 µg/mL, in reaction with synthetic chromogen and physiological substrate (arachidonic acid), respectively). In silico studies on interactions of main components of the Pulmonaria extracts with the COX-2 demonstrated the abilities of ten compounds to bind with the enzyme, including rosmarinic acid, menisdaurin, globoidnan A and salvianolic acid H.

Sorbus domestica Leaf Extracts and Their Activity Markers: Antioxidant Potential and Synergy Effects in Scavenging Assays of Multiple Oxidants

Sorbus domestica leaves are a traditionally used herbal medicine recommended for the treatment of oxidative stress-related diseases. Dry leaf extracts (standardized by LC-MS/MS and LC-PDA) and nine model activity markers (polyphenols), were tested in scavenging assays towards six in vivo-relevant oxidants (O2•-, OH•, NO•, H2O2, ONOO-, HClO). Ascorbic acid (AA) and Trolox (TX) were used as positive standards. The most active extracts were the diethyl ether and ethyl acetate fractions with activities in the range of 3.61-20.03 µmol AA equivalents/mg, depending on the assay. Among the model compounds, flavonoids were especially effective in OH• scavenging, while flavan-3-ols were superior in O2•- quenching. The most active constituents were quercetin, (-)-epicatechin, procyanidins B2 and C1 (3.94-24.16 µmol AA/mg), but considering their content in the extracts, isoquercitrin, (-)-epicatechin and chlorogenic acid were indicated as having the greatest influence on extract activity. The analysis of the synergistic effects between those three compounds in an O2•- scavenging assay demonstrated that the combination of chlorogenic acid and isoquercitrin exerts the greatest influence. The results indicate that the extracts possess a strong and broad spectrum of antioxidant capacity and that their complex composition plays a key role, with various constituents acting complementarily and synergistically.

The Pros and Cons of Cystic Fibrosis (CF) Patient Use of Herbal Supplements Containing Pulmonaria officinalis L. Extract: the Evidence from an In Vitro Study on Staphylococcus aureus CF Clinical Isolates

The justification for the use of herbal supplements with Pulmonaria officinalis L. extract (POE) in the case of staphylococcal lung colonization/infections characteristic for cystic fibrosis (CF), was examined in vitro. The impact of POE phenolic-rich fraction on the virulence attributes of CF-associated Staphylococcus aureus (S. aureus) clinical strains has been assessed, including pathogen adhesion, biofilm formation on native and protein-conditioned surfaces (mucin, elastin), mature biofilm eradication, staphylococcal protein A expression, α-toxin release, and S. a. adhesion to A549 cells. Cytotoxicity of the extract to lung epithelial cells was also investigated. It was found that POE has bacteriostatic effects at MIC 1⁻2 mg/mL, recognized as of limited efficacy, but at MIC/subMICs it targeted virulence not viability. It usually decreased S. aureus adhesion and less frequently inhibited biofilm formation on native and protein-conditioned surfaces. Observed effect seems to be related to significant reduction by POE of sortase A activity. However, in some cases POE favored the creation of biofilm by staphylococci and S. aureus adhesion to the lung epithelium was not limited. On the other side POE caused significant decrease of S. a. α-toxin synthesis and slightly weakened the expression of SpA. When used at supraMICs POE eradicated mature biofilm, but in some cases with unsatisfying outcomes. Promisingly, POE has been recognized as a safe product, with no cytotoxicity up to 4 mg/mL. These results reflect the positive, negative or neutral anti-staphylococcal properties of POE. It seems that POE may be beneficial as a prophylactic, but not as a therapeutic or supportive agent in the area of CF-integrative medicine. However, introduction the official recommendations needs further in vivo studies.

The Effect of Standardised Flower Extracts of Sorbus aucuparia L. on Proinflammatory Enzymes, Multiple Oxidants, and Oxidative/Nitrative Damage of Human Plasma Components In Vitro

Polyphenol-rich plant extracts might alleviate the negative impact of oxidative stress and inflammation, but careful phytochemical standardisation and evaluation of various mechanisms are required to fully understand their effects. In this context, flower extracts of Sorbus aucuparia L.-a traditional medicinal plant-were investigated in the present work. The LC-MS/MS profiling of the extracts, obtained by fractionated extraction, led to the identification of 66 constituents, mostly flavonols (quercetin and sexangularetin glycosides with dominating isoquercitrin), pseudodepsides of quinic and shikimic acids (prevailing isomers of chlorogenic acid and cynarin), and flavanols (catechins and proanthocyanidins). Minor extract components of possible chemotaxonomic value were flavalignans (cinchonain I isomers) and phenylamides (spermidine derivatives). As assessed by HPLC-PDA and UV-spectrophotometric studies, the extracts were polyphenol-abundant, with the contents up to 597.6 mg/g dry weight (dw), 333.9 mg/g dw, 382.0 mg/g dw, and 169.0 mg/g dw of total phenolics, flavonoids, proanthocyanidins, and caffeoylquinic acids, respectively. Their biological in vitro effects were phenolic-dependent and the strongest for diethyl ether, ethyl acetate, and n-butanol fractions of the methanol-water (7 : 3, v/v) extract. The extracts showed significant, concentration-dependent ability to scavenge in vivo-relevant radical/oxidant agents (O₂ ^∙-, OH^∙, H₂O₂, ONOO^-, NO^∙, and HClO) with the strongest effects towards OH^∙, ONOO^-, HClO, and O₂ ^∙- (compared to ascorbic acid). Moreover, the extracts efficiently inhibited lipoxygenase and hyaluronidase (compared to indomethacin) but were inactive towards xanthine oxidase. At in vivo-relevant levels (1-5 μg/mL), they also effectively protected human plasma components (proteins and lipids) against ONOO^--induced oxidative damage (reduced the levels of 3-nitrotyrosine, lipid hydroperoxides, and thiobarbituric acid-reactive substances) and normalised/enhanced the total nonenzymatic antioxidant capacity of plasma. In cytotoxicity tests, the extracts did not affect the viability of human PBMCs and might be regarded as safe. The results support the application of the extracts in the treatment of oxidative stress-related pathologies cross-linked with inflammatory changes.

Biosynthesis, Chemistry, and Pharmacology of Polyphenols from Chinese Salvia Species: A Review

Salvia species find widespread application in food and pharmaceutical products owing to their large polyphenol content. The main polyphenols in Chinese Salvia species are phenolic acids and flavonoids, which exhibit anti-oxygenation, anti-ischemia-reperfusion injury, anti-thrombosis, anti-tumour, and other therapeutic effects. However, there are few peer-reviewed studies on polyphenols in Chinese Salvia species, especially flavonoids. This review is a systematic, comprehensive collation of available information on the biosynthesis, chemistry, and pharmacology of Chinese Salvia species. We believe that our study makes a significant contribution to the literature because this review provides a detailed literary resource on the currently available information on various polyphenolic components of Chinese Salvia species, including their bioactivities and structures. In addition, the study provides information that would encourage further investigation of this plant material as a natural resource with potential for a broad range of applications in various industries, such as the food and pharmaceutical industries.

Polyphenol-Rich Extracts from Cotoneaster Leaves Inhibit Pro-Inflammatory Enzymes and Protect Human Plasma Components against Oxidative Stress In Vitro

The present study investigated the phenolic profile and biological activity of dry extracts from leaves of C. bullatus, C. zabelii and C. integerrimus-traditional medicinal and dietary plants-and evaluated their potential in adjunctive therapy of cardiovascular diseases. Complementary UHPLC-PDA-ESI-MS³, HPLC-PDA-fingerprint, Folin-Ciocalteu, and n-butanol/HCl assays of the extracts derived by fractionated extraction confirmed that they are rich in structurally diverse polyphenols (47 analytes, content up to 650.8 mg GAE/g dw) with proanthocyanidins (83.3⁻358.2 mg CYE/g) dominating in C. bullatus and C. zabelii, and flavonoids (53.4⁻147.8 mg/g) in C. integerrimus. In chemical in vitro tests of pro-inflammatory enzymes (lipoxygenase, hyaluronidase) inhibition and antioxidant activity (DPPH, FRAP), the extracts effects were dose-, phenolic- and extraction solvent-dependent. The most promising polyphenolic extracts were demonstrated to be effective antioxidants in a biological model of human blood plasma-at in vivo-relevant levels (1⁻5 µg/mL) they normalized/enhanced the non-enzymatic antioxidant capacity of plasma and effectively prevented peroxynitrite-induced oxidative/nitrative damage of plasma proteins and lipids. As demonstrated in cytotoxicity tests, the extracts were safe-they did not affect viability of human peripheral blood mononuclear cells. In conclusion, Cotoneaster leaves may be useful in development of natural-based products, supporting the treatment of oxidative stress/inflammation-related chronic diseases, including cardiovascular disorders.

Novel Phenolic Constituents of Pulmonaria officinalis L. LC-MS/MS Comparison of Spring and Autumn Metabolite Profiles

Lungwort (Pulmonaria officinalis L., Boraginaceae) is considered to possess therapeutic properties and it has been traditionally used as a remedy against various lung disorders in many countries. Nevertheless, very few data concerning its phytochemical composition are available. This research aims to provide a detailed description of specialized metabolites from the aerial parts of lungwort. Nine previously undescribed and 36 known phenolic compounds were detected in the 50% methanolic extract. Following multistep preparative procedures, structures of newly discovered compounds were determined using one- and two-dimensional techniques of NMR spectroscopy. Among the identified compounds were caffeic acid esters with aliphatic hydroxycarboxylic acids, conjugates of dicaffeic acid with rosmarinic acid, and previously unknown isomers of isosalvianolic acid A and yunnaneic acid E, as well as other lignans. Concentrations of all identified phenolic derivatives in the investigated herbal material were estimated using a method based on liquid chromatography with high-resolution mass spectrometry detection. Seasonal changes in the concentration of metabolites were also investigated using targeted and untargeted metabolomics techniques.

γ-Pyrone compounds: flavonoids and maltol glucoside derivatives from Herniaria glabra L. collected in the Ternopil region of the Ukraine

The phytochemical investigation of the whole plant extracts of Herniaria glabra L. (Caryophyllaceae) led to the identification and isolation of four known flavonoids, one known and three undescribed maltol derivatives, and benzyl β-gentiobioside. The structures were established by extensive 1D and 2D NMR spectroscopic analyses, as well as HRESIMS data. For the first time in Herniaria genus, as well as in Caryophylaceae family the presence of apiorutin {quercetin 3-O-[(D-apio-β-d-furanosyl-(1 → 2)-O-[-α-l-rhamnopyranosyl-(1 → 6)]-β-d-glucopyranoside]} and licoagroside B {maltol 3-O-[6-O-(3-hydroxy-3-methylglutaroyl)]-β-d-glucopyranoside} were revealed. Additionally, antioxidant actions of apiorutin, rutin, narcissin (isorhamentin 3-O-β-d-rutinoside) and licoagroside B were assessed in human blood plasma, exposed to the peroxynitrite-induced oxidative stress in vitro. The isolates partly reduced oxidative (oxidation of thiol groups) and nitrative (tyrosine nitration) damage to blood plasma proteins, decreased plasma lipid peroxidation as well as enhanced the non-enzymatic antioxidant capacity of blood plasma. No cytotoxicity of the examined substances towards peripheral blood mononuclear cells was found.

Phenolic fractions from nine Trifolium species modulate the coagulant properties of blood plasma in vitro without cytotoxicity towards blood cells

OBJECTIVE

The study covers an evaluation of the influence of extracts (1-50 μg/ml), isolated from aerial parts of nine Trifolium L. species (i.e. T. alexandrinum, T. fragiferum, T. hybridum, T. incarnatum, T. pallidum, T. pratense, T. resupinatum var. majus, T. resupinatum var. resupinatum and T. scabrum) on haemostatic properties of blood plasma.

METHODS

The clot formation and fibrinolysis assay (CFF), blood clotting times, the extrinsic and intrinsic coagulation pathway-dependent polymerization of plasma fibrin were measured. The effects of plant extracts on amidolytic activity of thrombin were also evaluated and compared with argatroban, an antithrombotic drug. Cytotoxicity was assessed in a model of blood platelets and as the viability of peripheral blood mononuclear cells.

KEY FINDINGS

While no changes in blood clotting times or fibrinolytic properties of blood plasma were found, some fractions impaired the blood plasma coagulation induced by the intrinsic coagulation pathway. Reduction in the maximal velocity of fibrin polymerization was also observed in the clot formation and fibrinolysis assay. No cytotoxicity of Trifolium extracts towards the investigated cells was recorded.

CONCLUSIONS

The most efficient anticoagulant activity in plasma was found for T. fragiferum and T. incarnatum extracts, while the T. alexandrinum fraction was the most effective inhibitor of thrombin amidolytic activity.

A Si-rhodamine-based near-infrared fluorescent probe for visualizing endogenous peroxynitrite in living cells, tissues, and animals

An aromatic tertiary amine-functionalized Si-rhodamine dye has been exploited as a near-infrared fluorescent probe for visualizing endogenous peroxynitrite in living cells, tissues, and mice.