Comprehensive polyoxypregnane glycosides report in Caralluma quadrangula using UPLC-ESI-Q-TOF and their antioxidant effects in human plasma.

ETHNOPHARMACOLOGICAL RELEVANCE: Caralluma quadrangula (Forssk.) N.E.Br. (Syns: = Stapelia quadrangula Forssk. = Monolluma quadrangula Forssk.) is an indigenous member of the genus Caralluma and it is a rather common species on rocky hillsides in the southwestern part of Saudi Arabia. Several members of this genus have found medicinal uses in the treatment of rheumatism, diabetes, leprosy and as antiseptics and disinfectants. All parts are edible but rather more bitter and can cause diarrhea. AIM OF THE STUDY: The present report was tentatively elucidated the structure of acylated and non-acylated polyoxypregnane glycosides from Caralluma quadrangula. MATERIALS AND METHODS: The analyses were performed using an electrospray-ionization quadrupole time-of-flight (ESI-Q-TOF) mass spectrometer in both positive and negative ionization modes to explore fragmentation pathways. The antioxidant and prooxidant properties of the different mobility portions of human plasma were evaluated in vitro using thiobarbituric acid reactive substance assay (TBARS). RESULTS: The analyses showed sixty-five characteristic ion peaks which could be more efficient to assignment the aglycones and fragmentation sequences of sugar moieties. The used ionization modes provided consistent and/or complementary information for most of the pregnane glycosides, their fragmentation sequences, and their aglycones. A DFT Study was performed to elucidate the neutral loss of H2O molecules sequences from aglycones and the esterification linkage. CONCLUSIONS: This report could be useful to reduce material consuming and time in phytochemistry analysis of the different medicinal plants. The two portions significantly depleted TBARS were subjected to autoperoxidation assay in the presence of hydrogen peroxide.

Qualitative and Quantitative Analysis of Secondary Metabolites in Morphological Parts of Paulownia Clon In Vitro 112® and Their Anticoagulant Properties in Whole Human Blood.

It is not easy to find data in the scientific literature on the quantitative content of individual phytochemicals. It is possible to find groups of compounds and even individual compounds rather easily, but it is not known what their concentration is in cultivated or wild plants. Therefore, the subject of this study was to determine the content of individual compounds in the new Paulownia species, Oxytree, developed in a biotechnology laboratory in 2008 at La Mancha University in Spain. Six secondary metabolites were isolated, and their chemical structure was confirmed by spectral methods. An analytical method was developed, which was then used to determine the content of individual compounds in leaves, twigs, flowers and fruits of Paulownia Clon in Vitro 112®. No flavonoids were found in twigs and fruits of Oxytree, while the highest phenylethanoid glycosides were found in twigs. In this study, we also focused on biological properties (anticoagulant or procoagulant) of extract and four fractions (A-D) of different chemical composition from Paulownia Clon in Vitro 112 leaves using whole human blood. These properties were determined based on the thrombus-formation analysis system (T-TAS), which imitates in vivo conditions to assess whole blood thrombogenecity. We observed that three fractions (A, C and D) from leaves decrease AUC10 measured by T-TAS. In addition, fraction D rich in triterpenoids showed the strongest anticoagulant activity. However, in order to clarify the exact mechanism of action of the active substances present in this plant, studies closer to physiological conditions, i.e., in vivo studies, should be performed, which will also allow to determine the effects of their long-term effects.

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.

Electrospray ionization mass spectrometry characterization of ubiquitous minor lipids and oligosaccharides in milk of the camel (Camelus dromedarius) and their inhibition of oxidative stress in human plasma.

The aim of this study was to characterize minor lipids in methanol fraction extracted from raw camel milk after loading it on a water-preconditioned short C18 open column and fractionating with a gradient of methanol/water. The C18 column showed high fractionation efficiency of minor lipids, such as glycosphingolipids, lipopolysaccharides, or oligosaccharides, when compared with other constituents, in particular polysaccharides, proteins, and free fatty acids. Liquid chromatography electrospray ionization tandem mass spectrometry in negative ion mode was used to identify 21 new glycosphingolipids, lipopolysaccharides, and oligosaccharides. Electrospray ionization tandem mass spectrometry was qualified to provide relevant data for recognizing the molecular mass, glycosylation sequences, and structure of saccharide moieties for the revealed compounds. The sequence of combinations of one selected lipopolysaccharide, which was considered the backbone of the remaining lipopolysaccharides, was confirmed in a density functional theory study. The obtained results showed that the tested fraction is a rich source of glycosphingolipids, lipopolysaccharides, and oligosaccharides with antioxidant activity.

The Effect of Hydrogen Sulfide on Different Parameters of Human Plasma in the Presence or Absence of Exogenous Reactive Oxygen Species.

The main aim of the study is to examine the effect of sodium hydrosulfide (NaHS), an H2S donor, on the oxidative stress in human plasma in vitro. It also examined the effects of very high concentrations of exogenous hydrogen sulfide on the hemostatic parameters (coagulation and fibrinolytic activity) of human plasma. Plasma was incubated for 5-30 min with different concentrations of NaHS from 0.01 to 10 mM. Following this, lipid peroxidation was measured as a thiobarbituric acid reactive substance (TBARS) concentration and the oxidation of amino acid residues in proteins was measured by determining the amounts of thiol groups and carbonyl groups. Hydrogen peroxide (H2O2) and the hydroxyl radical generating oxidation system (Fe/H2O2) were used as oxidative stress inducers. Hemostatic factors, such as the maximum velocity of clot formation, fibrin lysis half-time, the activated partial thromboplastin time (APTT), thrombin time (TT), and international normalized ratio (INR), were estimated. Changes in lipid peroxidation, carbonyl group formation, and thiol group oxidation were detected at high concentrations of H2S (0.1-10 mM), and these results indicate that NaHS (as the precursor of H2S) may have pro-oxidative effects in human plasma in vitro. Moreover, considering the data presented in this study, we suggest that the oxidative stress stimulated by NaHS (at high concentrations: 1-10 mM) is not involved in changes of the hemostatic activity of plasma.

Anti-Platelet Properties of Phenolic Extracts from the Leaves and Twigs of Elaeagnus rhamnoides (L.) A. Nelson.

Sea buckthorn (Elaeagnus rhamnoides (L.) A. Nelson) is a small tree or bush. It belongs to the Elaeagnaceae family, and has been used for many years in traditional medicine in both Europe and Asia. However, there is no data on the effect of sea buckthorn leaves and twigs on the properties of blood platelets. The aim of the study was to analyze the biological activity of phenolic extracts from leaves and twigs of sea buckthorn in blood platelets in vitro. Two sets of extracts were used: (1) phenolic compounds from twigs and (2) phenolic compounds from leaves. Their biological effects on human blood platelets were studied by blood platelet adhesion, platelet aggregation, arachidonic acid metabolism and the generation of superoxide anion. Cytotoxicity was also evaluated against platelets. The action of extracts from sea buckthorn twigs and leaves was compared to activities of the phenolic extract (a commercial product from the berries of Aronia melanocarpa (Aronox®) with antioxidative and antiplatelet properties. This study is the first to demonstrate that extracts from sea buckthorn leaves and twigs are a source of bioactive compounds which may be used for the prophylaxis and treatment of cardiovascular pathologies associated with blood platelet hyperactivity. Both leaf and twig extracts were found to display anti-platelet activity in vitro. Moreover, the twig extract (rich in proanthocyanidins) displayed better anti-platelet potential than the leaf extract or aronia extract.

Oxidative Stress and Hemostatic Parameters in Patients With Nephrolithiasis Before and After Ureteroscopic Lithotripsy.

PURPOSE: In patients with nephrolithiasis, oxidative stress, especially lipid peroxidation is observed. Moreover, various invasive methods [including extracorporeal shock wave lithotripsy (ESWL)] for treatment of nephrolithiasis may induce not only the oxidative stress, but they may modulate hemostasis. The study was aimed to evaluate the oxidative damages of lipids and proteins in patients with nephrolithiasis (before and after ureteroscopic lithotripsy - URSL). The aim of the present study was also determine selected parameters of hemostasis in these patients. METHODS: 56 patients with nephrolithiasis and 49 healthy participants were included: 30 men and 26 women (for patient group); 27 men and 22 women (for healthy group). We measured the level of selected typical two biomarkers of oxidative modification of lipids [such as the production of thiobarbituric acid reactive substances (TBARS) and isoprostane concentration (8-isoPGF2α)] and two biomarkers of oxidative damages of proteins (carbonylation and the level of thiol groups) in patients with nephrolithiasis (before and after URSL). The following parameters of hemostasis were measured: blood platelet count, the level of fibrinogen and D-dimer, and coagulation times (the activated partial thromboplastin time (APTT), prothrombin time (PT), and thrombin time (TT) of plasma). RESULTS: Different levels of plasma lipid peroxidation were observed in patients with nephrolithiasis before URSL and after URSL. However, no such difference in the level of oxidative damage to plasma proteins was observed. In addition, the tested hemostasis parameters were not influenced by the presence of nephrolithiasis, nor by treatment with URSL. CONCLUSION: We suggest URSL does not induce the oxidative modifications of plasma proteins and does not change hemostatic parameters in patients with nephrolithiasis.

Biological properties of Elaeagnus rhamnoides (L.) A. Nelson twig and leaf extracts.

BACKGROUND: Sea buckthorn (Elaeagnus rhamnoides (L.) A. Nelson, SBT) is a valuable plant because of its medical and therapeutic potential. Different bioactive compounds in SBT berries are of special interest to various researchers. However, not only sea buckthorn berries, but also leaves of this plant (both fresh and dried) contain a lot of nutrients and bioactive compounds, including phenolic compounds. The present study was carried out in order to investigate antioxidant and anticoagulant properties of sea buckthorn twig and leaf extracts (0.5-50 µg/mL) by using various in vitro models. Moreover, the aim of present experiments was to compare the biological activity of SBT leaf extract and SBT twig extract with selected berry extracts (a rich source of phenolic compounds): SBT berry extract (flavonoids being the dominant components), a commercial extract from the berries of Aronia melanocarpa (Aronox®), and a grape seed extract. METHODS: We determined the effect of plant extracts on the oxidative stress using selected markers of this process, i.e. the level of carbonyl groups in proteins. Additionally, we analysed the potential mechanism of modulation of hemostatic properties of human plasma (using selected coagulation times). RESULTS: SBT twig and leaf extracts were observed to exhibit an antioxidant activity against two strong biological oxidants: hydrogen peroxide (H2O2) and H2O2/Fe (the donor of hydroxyl radicals), which induced human plasma lipid peroxidation and protein carbonylation. Both extracts also showed anticoagulant properties. CONCLUSIONS: Our present results have demonstrated that extracts from different parts of SBT, especially berries and twigs, in comparison to well-known berries (aronia and grape), may also be viewed as a good source of active substances - antioxidants for pharmacological or cosmetic applications. Moreover, it is very important from an economic point of view to know that there is a possibility of obtaining phenolic compounds not only from the berries or leaves, but also from twigs, which constitute a production waste.

Isorhamnetin and its new derivatives isolated from sea buckthorn berries prevent H2O2/Fe - Induced oxidative stress and changes in hemostasis.

The objective of this study is to investigate the biological effects of phenolic compounds extracted from the sea buckthorn berries on oxidative stress and hemostasis. The sea buckthorn (Elaeagnus rhamnoides (L.) A. Nelson) berries are rich in flavonoids and non-polar compounds. In this study, the activity of the phenolic fraction from the sea buckthorn berries was evaluated in vitro in comparison with three phenolic compounds: isorhamnetin (compound 1) and its two new derivatives: compound 2 (isorhamnetin 3-O-beta-glucoside-7-O-alfa-rhamnoside) and compound 3 (isorhamnetin 3-O-beta-glucoside-7-O-alfa-(3"'-isovaleryl)-rhamnoside). The impact of these phenolic compounds and the phenolic fraction against the effect of the donor of hydroxyl radicals - H2O2/Fe on proteins and lipids in human plasma was measured. Additionally, the aim of the study was to determine the effect of these phenolic compounds and the phenolic fraction on various typical hemostasis parameters. Our results show that the used derivatives of isorhamnetin possess different biological properties (e.g. antioxidant, anti-platelet and anticoagulant). The tested compounds can be seen as new natural beneficial compounds to be used in prevention and treatment of cardiovascular diseases.

Evaluation of antioxidant activity of extracts from the roots and shoots of Scutellaria alpina L. and S. altissima L. in selected blood cells.

BACKGROUND: It is widely known that reactive oxygen species (ROS) can cause oxidative damage in cells and have been linked to the pathogenesis of oxidative diseases, such as atherosclerosis, ischemia, neurodegenerative disease, diabetes, or cancer. Recently, much attention has been focused on preventive strategies for oxidative stress and related diseases. Plants represent a source of bioactive compounds whose antioxidant activity may be useful in protecting against pro-oxidative reactions. OBJECTIVES: The study determines the in vitro biological activity of the ethanolic extracts from the shoots and roots of Scutellaria species (S. altissima and S. alpina) in selected blood cells (blood platelets and lymphocytes). MATERIAL AND METHODS: Platelet activity, both resting and after thrombin stimulation, was used to indicate the ability of the plant extracts to inhibit the production of superoxide anion radicals (O2 •-) and platelet lipid peroxidation. The generation of superoxide anion radicals was measured by cytochrome c reduction. Lipid peroxidation in blood platelets was measured by the level of thiobarbituric acid reactive substances (TBARS). The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay was used to determine the protective effect of Scutellaria extracts on lymphocyte cells against oxidative damage induced by hydroxyl radicals. RESULTS: Extracts (5-50 µg/mL) containing phenolic compounds from both Scutellaria species distinctly reduced nonenzymatic lipid peroxidation and arachidonic acid metabolism by blood platelets in vitro. When given at the tested concentration, the extracts reduced the generation of O2 •- in resting blood platelets and platelets activated by thrombin in vitro. All Scutellaria extracts (10 µg/mL) containing phenolic compounds also protected human lymphocytes against oxidative stress induced by hydrogen peroxide (H2O2). CONCLUSIONS: The present study suggests that the natural extracts from S. altissima and S. alpina have antioxidant properties and, therefore, may be beneficial in the prevention of diseases in which blood platelets and lymphocytes are involved, i.e., cancer or inflammatory and infective diseases.

The lipid peroxidation in patients with nephrolithiasis before and after extracorporeal shock wave lithotripsy.

AIM: To evaluate the level of lipid peroxidation in patients with nephrolithiasis before and after extracorporeal shock wave lithotripsy (ESWL). MATERIALS & METHODS: Isoprostane concentration (8-isoPGF2α) was measured in urine, and thiobarbituric acid reactive substance production in serum and erythrocytes. In addition, the concentrations of selected compounds (uric acid, glucose and creatinine) were measured in serum. RESULTS: The patients (before and after ESWL) demonstrated significantly higher levels of two different biomarkers of lipid peroxidation compared with the control group. A correlation was identified between increased amounts of uric acid and biomarkers of lipid peroxidation in patients with nephrolithiasis, both before and after ESWL. CONCLUSION: Uric acid may be associated with lipid peroxidation in patients with nephrolithiasis.

Phenolic fraction and nonpolar fraction from sea buckthorn leaves and twigs: chemical profile and biological activity.

AIM: The main objective of our studies was to determine the chemical composition and biological activities (antioxidant and anticoagulant properties) of two standardized phenolic fractions from sea buckthorn twig and leaf, and two standardized nonpolar fractions from twig and leaf in human plasma in vitro. MATERIAL & METHODS: Appropriately prepared extracts from sea buckthorn twigs and leaves were used. Markers of oxidative stress and hemostasis were determined in this work. RESULTS: The reduction of plasma lipid peroxidation induced by H2O2/Fe was observed for two fractions from twig. Analysis of the effect on the coagulation properties of plasma demonstrated that the nonpolar fraction from twig and the phenolic fraction from leaf, significantly prolonged the activated partial thromboplastin time and the prothrombin time, respectively. CONCLUSION: Sea buckthorn twig and leaf are new promising plant materials in the prophylaxis and treatment of cardiovascular disorders.

Comparative chemical composition, antioxidant and anticoagulant properties of phenolic fraction (a rich in non-acylated and acylated flavonoids and non-polar compounds) and non-polar fraction from Elaeagnus rhamnoides (L.) A. Nelson fruits.

This study focuses on two fractions from sea buckthorn (Elaeagnus rhamnoides (L.) A. Nelson) fruits: the phenolic fraction (rich in non-acylated and acylated flavonoids and non-polar compounds) and the non-polar fraction. The objective was to investigate both the chemical composition of these fractions, as well as their biological activities in vitro. The tested fractions of sea buckthorn inhibited lipid peroxidation induced by H2O2, however, the non-polar fraction reduced more powerfully the process induced by H2O2/Fe as compared to the phenolic fraction. The tested fractions of sea buckthorn fruits also inhibited carbonylation stimulated by H2O2/Fe. Moreover, the action of the phenolic fraction and non-polar fraction on hemostatic parameters of plasma was also compared to activities of other phenolic fraction, in which flavonoids were the dominant compounds. Our results indicate that sea buckthorn fruits are a rich source of different secondary metabolites, i.e. triterpenes and their derivates, which possess not only antioxidant properties, but may also display anticoagulant attributes.

Evaluation of hemostasis parameters and the role of the oxidative damage to plasma proteins in the modulation of hemostasis in patients with nephrolithiasis before and after extracorporeal shock wave lithotripsy.

PURPOSE: Extracorporeal shock wave lithotripsy (ESWL) is a commonly-used method in urology, which may modulate hemostasis and may induce lipid peroxidation in patients with nephrolithiasis. However, previous studies only examine changes occurring in patients 30-240 min after ESWL. The main aim of the present study was to determine whether oxidative stress may modulate the hemostatic activity of plasma in patients with nephrolithiasis before ESWL and the day after treatment ESWL. This will be performed by measuring selected parameters of hemostasis in these patients, both before ESWL and the following day, and assessing the level of oxidative damage to plasma proteins in these patients by measuring two biomarkers. METHODS: Twelve patients with nephrolithiasis and 10 healthy participants were included. The following parameters of hemostasis were measured: the activated partial thromboplastin time (APTT), prothrombin time (PT), and thrombin time (TT) of plasma, the level of fibrinogen, the level of D-dimer and blood platelet count. In addition, two selected biomarkers of oxidative stress were measured: protein carbonylation level and the number of protein thiol groups. RESULTS: No difference was observed between patients with nephrolithiasis before and after ESWL and healthy controls with regard to PT, TT or APTT. Fibrinogen concentration and blood platelet count were lower in the nephrolithiasis patients in the period after ESWL than before ESWL. The nephrolithiasis patients demonstrated elevated D-dimer concentration after ESWL. However, although oxidative damage was observed in the plasma proteins in the nephrolithiasis patients, this was not influenced by ESWL. CONCLUSION: Oxidative stress may induce changes of hemostasis in patients with nephrolithiasis, both before and after ESWL. In addition, changes of hemostasis parameters such as fibrinogen, blood platelet count and D-dimer level can be observed in these patients, especially after ESWL, and this may suggest that ESWL modulates hemostasis. By having a better understanding of the influence of ESWL on hemostasis, this could lead to modifying patient care for those patients at increased risk of bleeding.

Cyclic Diarylheptanoids from Corylus avellana Green Leafy Covers: Determination of Their Absolute Configurations and Evaluation of Their Antioxidant and Antimicrobial Activities.

The methanol extract of the leafy covers of Corylus avellana, source of the Italian PGI (protected geographical indication) product "Nocciola di Giffoni", afforded two new cyclic diarylheptanoids, giffonins T and U (2 and 3), along with two known cyclic diarylheptanoids, a quinic acid, flavonoid-, and citric acid derivatives. The structures of giffonins T and U were determined as highly hydroxylated cyclic diarylheptanoids by 1D and 2D NMR experiments. Their relative configurations were assigned by a combined quantum mechanical/NMR approach, comparing the experimental 13C/1H NMR chemical shift data and the related predicted values. The absolute configurations of carpinontriol B (1) and giffonins T and U (2 and 3) were assigned by comparison of their experimental electronic circular dichroism curves with the TDDFT-predicted curves. The ability of the compounds to inhibit the lipid peroxidation induced by H2O2 and H2O2/Fe2+ was determined by measuring the concentration of thiobarbituric acid reactive substances. Furthermore, the antimicrobial activity of the methanol extract of leafy covers of C. avellana and of the isolated compounds against the Gram-positive strains Bacillus cereus and Staphylococcus aureus and the Gram-negative strains Escherichia coli and Pseudomonas aeruginosa was evaluated. Carpinontriol B (1) and giffonin U (3) at 40 µg/disk caused the formation of zones of inhibition.

Evaluation of antioxidant activity of phenolic fractions from the leaves and petals of dandelion in human plasma treated with H2O2 and H2O2/Fe.

Taraxacum officinale (dandelion) is a widespread perennial of the Asteraceae family. Dandelion is a rich source of different bioactive compounds, including phenolic compounds, terpenes, carbohydrates, proteins, fatty acids, vitamin and minerals. However, the content of phenolics in tested extracts by various authors was not always well described. Dandelion is also a commonly available food with a long history of human use and as such poses little risk of harm. In this study, we focused on four different phenolic fractions from leaves and petals of dandelion, which might be of great interest. The objective was to investigate the antioxidant properties of the phenolic fractions from dandelion leaves and petals in vitro. Effects of four different phenolic fractions from dandelion leaves and petals on the production of thiobarbituric acid reactive substances (TBARS, a marker of lipid peroxidation) in human plasma were studied in vitro. Their antioxidant properties against human plasma protein carbonylation and oxidation of protein thiols induced by a strong biological oxidant - hydrogen peroxide (H2O2) or H2O2/Fe (a donor of hydroxyl radicals) were also examined. The tested fractions of dandelion (0.5-50 µg/mL; the incubation time - 30 min) inhibited plasma lipid peroxidation induced by H2O2 or H2O2/Fe. However, their antioxidant properties were not concentration-dependent. All tested samples also inhibited plasma protein carbonylation and oxidation of thiol groups in plasma proteins stimulated by oxidants (H2O2 and OH∙). The obtained results suggest that four tested dandelion fractions, especially phenolic fractions from petals which are recognized as better than leaves source of flavonoids, may be a new and promising source of natural compounds with antioxidant activity beneficial for diseases-associated with oxidative stress, and with changes of hemostasis.

Quali-quantitative analysis of the phenolic fraction of the flowers of Corylus avellana, source of the Italian PGI product "Nocciola di Giffoni": Isolation of antioxidant diarylheptanoids.

There is only limited information available on the chemical composition of the non-edible parts of Corylus avellana, source of the Italian PGI product "Nocciola di Giffoni" (hazelnut). An initial LC-MS profile of the methanolic extract of the male flowers of C. avellana, cultivar 'Tonda di Giffoni' led to the isolation of 12 compounds, of which the structures were elucidated by NMR spectroscopy. These were identified as three previously undescribed diarylheptanoids, named giffonins Q-S, along with nine known compounds. Furthermore, the quantitative determination of the main compounds occurring in the methanolic extract of C. avellana flowers was carried out by an analytical approach based on LC-ESI(QqQ)MS, using the Multiple Reaction Monitoring (MRM) experiment. In order to explore the antioxidant ability of C. avellana flowers, the methanolic extract and the isolated compounds were evaluated for their inhibitory effects on human plasma lipid peroxidation induced by H2O2 and H2O2/Fe(2+), by measuring the concentration of TBARS.

ANTIOXIDANT PROPERTIES OF METHANOLIC EXTRACTS FROM THE SHOOTS AND ROOTS OF pRi-TRANSFORMED PLANTS OF REHMANNIA GLUTINOSA LIBOSCH.

The antioxidant activity of methanolic extracts derived from shoots (HR-shoots) and roots (HR-roots) of pRi-transformed Rehmannia glutinosa plants were determined. The activity was indicated by the ability of the plant extracts to inhibit superoxide anion (O2(-·)) generation and thiobarbituric acid reactive substances (TBARS) production in resting blood platelets and platelets activated by thrombin. The strongest activity was exhibited by the HR-shoot extract (50 µg/mL). The present study also examines the antioxidant properties of the plant extracts against human plasma lipid peroxidation induced by strong biological oxidants: hydrogen peroxide (H2O2) and H2O2/Fe. The study shows that extracts from transformed R. glutinosa plants may be a promising source of natural antioxidants, which would be valuable in various cardiovascular diseases. The extracts may also protect lipids against oxidative modifications.

Hippophae rhamnoides L. Fruits Reduce the Oxidative Stress in Human Blood Platelets and Plasma.

Effects of the phenolic fraction from Hippophae rhamnoides fruits on the production of thiobarbituric acid reactive substances (TBARS, a marker of lipid peroxidation) and the generation of superoxide anion (O2 (-∙)) in human blood platelets (resting platelets and platelets stimulated by a strong physiological agonist, thrombin) were studied in vitro. We also examined antioxidant properties of this fraction against human plasma lipid peroxidation and protein carbonylation induced by a strong biological oxidant, hydrogen peroxide (H2O2) or H2O2/Fe (a donor of hydroxyl radicals). The tested fraction of H. rhamnoides (0.5- 50 µg/mL; the incubation time: 15 and 60 min) inhibited lipid peroxidation induced by H2O2 or H2O2/Fe. The H. rhamnoides phenolic fraction inhibited not only plasma lipid peroxidation, but also plasma protein carbonylation stimulated by H2O2 or H2O2/Fe. Moreover, the level of O2 (-∙) in platelets significantly decreased. In comparative experiments, the H. rhamnoides fraction was a more effective antioxidant than aronia extract or grape seed extract (at the highest tested concentration, 50 µg/mL). The obtained results suggest that H. rhamnoides fruits may be a new, promising source of natural compounds with antioxidant and antiplatelet activity beneficial not only for healthy people, but also for those with oxidative stress-associated diseases.

COMMERCIAL EXTRACT FROM ARONIA AS A MODULATOR OF ADHESIVE PROPERTIES OF FIBRINOGEN TREATED WITH HOMOCYSTEINE AND ITS THIOLACTONE IN VITRO.

Research has confirmed the positive effect of berries of Aivnia melanocarpa on the cardiovascular system. The protective effects of polyphenol-rich extract from berries of A. melanocarpa against changes in biological properties of fibrinogen were studied. In in vino model of hyperhomocysteinemia the capability of fibrinogen to interact with human blood platelets was measured by platelet adhesion in the presence of extract fromA. nelanocapa. We induced hyperhomocystenemia using a reduced form of homocysteine (Hey, at a final concentration of 0.01. 0.1 and 1 µM) and the most reactive form of Hey - its cyclic thioester, homocysteine thiolactone (HTL, at a final concentration of 0.1, 0.5 and I µM). It was observed that Hey or HTL-treated fibrinogen, in comparison with untreated molecule, had a distinct capability to mediate blood platelet adhesion. The experiments also indicate that polyphenol-rich extract from black chokeberries (at final concentrations of 2.5-10 pM/mL) reduced the toxic action of Hey and HTL on the adhesive properties of fibrinogen. The possible protection exerted by black chokeberry extract, through restoring the platelet adhesion of Hey or HTL treated fibrinogen, may be important for vascular diseases.