The changes of blood platelet reactivity in the presence of Elaeagnus rhamnoides (L.) A. Nelson leaves and twig extract in whole blood.

Uncontrolled blood platelet activation is an important risk factor of cardiovascular disease (CVDs). Various studies on phenolic compounds indicate that they have a protective effect on the cardiovascular system through different mechanisms, including the reduction of blood platelet activation. One of the plants that is particularly rich in phenolic compounds is sea buckthorn (Elaeagnus rhamnoides (L.) A. Nelson). The aim of the present study in vitro was to determine the anti-platelet properties of crude extracts isolated from leaves and twigs of E. rhamnoides (L.) A. Nelson in whole blood using flow cytometric and total thrombus-formation analysis system (T-TAS). In addition, the aim of our study was also analyze of blood platelet proteomes in the presence of different sea buckthorn extracts. A significant new finding is a decrease surface exposition of P-selectin on blood platelets stimulated by 10 µM ADP and 10 µg/mL collagen, and a decrease surface exposition of GPIIb/IIIa active complex on non-activated platelets and platelets stimulated by 10 µM ADP and 10 µg/mL collagen in the presence of sea buckthorn leaf extract (especially at the concentration 50 µg/mL). The twig extract also displayed antiplatelet potential. However, this activity was higher in the leaf extract than in the twig extract in whole blood. In addition, our present findings clearly demonstrate that investigated plant extracts have anticoagulant properties (measured by T-TAS). Therefore, the two tested extracts may be promising candidates for the natural anti-platelet and anticoagulant supplements.

Hippophae rhamnoides L. leaf and twig extracts as rich sources of nutrients and bioactive compounds with antioxidant activity.

Plants have served for centuries as sources of compounds useful for human health such as antioxidant, anti-diabetic and antitumor agents. They are also rich in nutrients that improve the human diet. Growing demands for these compounds make it important to seek new sources for them. Hippophae rhamnoides L. is known as a plant with health-promoting properties. In this study we investigated the chemical composition and biological properties of bioactive components of ethanol extracts from leaves and twigs of H. rhamnoides L. Chemical components such as the total content of phenolic compounds, vitamins and amino acids and the antioxidant activities of these compounds in cellular and cell-free systems were assessed. The results suggest that the studied extracts are rich in bioactive compounds with potent antioxidant properties. Cytotoxicity and hemotoxicity assays showed that the extracts had low toxicity on human cells over the range of concentrations tested. Interaction with human serum albumin was investigated and conformational changes were observed. Our results indicate that leaf and twig extracts of H. rhamnoides L. should be considered as a non-toxic source of bioactive compounds which may be of interest to the food, pharmaceutical and cosmetic industries.

Preparations from selected cucurbit vegetables as antiplatelet agents.

Increased blood platelet activation plays an important role in cardiovascular diseases (CVDs). Recent experiments indicate that certain fruits and vegetables, including onion, garlic, and beetroot, have anti-platelet potential and therefore may reduce the likelihood of CVDs. While vegetables from the Cucuritaceae family are known to exerting beneficial antioxidant and anti-inflammatory effects, their effects on blood platelet activation are poorly understood. Therefore, the aim of the present study was to determine the effect on platelet adhesion of preparations from selected cucurbits: pumpkin (Cucurbita pepo; fruit without seeds), zucchini (Cucurbita pepo convar. giromontina; fruit with seeds), cucumber (Cucumis sativus; fruit with seeds), white pattypan squash (Cucurbita pepo var. patisoniana; fruit without seeds) and yellow pattypan squash (Cucurbita pepo var. patisoniana, fruit without seeds). It also evaluates the activity of these preparations on enzymatic lipid peroxidation in thrombin-activated washed blood platelets by TBARS assay. The study also determines the anti-platelet properties of these five cucurbit preparations in whole blood by flow cytometry and with the total thrombus-formation analysis system (T-TAS) and evaluates the cytotoxicity of the tested preparations against platelets based on LDH activity. The results indicate that the yellow Cucurbita pepo var. patisoniana preparation demonstrated stronger anti-platelet properties than the other tested preparations, reducing the adhesion of thrombin-activated platelets to collagen/fibrinogen, and inhibiting arachidonic acid metabolism and GPIIb/IIIa expression on 10 µM ADP-activated platelets. None of the preparations was found to cause platelet lysis. Our findings provide new information on the anti-platelet activity of the tested cucurbit preparations and their potential for treating CVDs associated with platelet hyperactivity.

Antioxidant and anticoagulant effects of phenylpropanoid glycosides isolated from broomrapes (Orobanche caryophyllacea, Phelipanche arenaria, and P. ramosa).

Holoparasitic plants of the Orobanchaceae, including Cistanche, Orobanche, and Phelipanche spp, are known for their richness of phenylpropanoid glycosides (PPGs). Many PPG compounds have been found to possess a wide spectrum of activities, such as antimicrobial, anti-inflammatory, antioxidant, and memory-enhancing. To better explore the bioactivity potential of European broomrapes (O. caryophyllacea - OC, P. arenaria - PA, P. ramosa - PR) and ten single isolated phenylpropanoid constituents, we investigated their antiradical action, protective effect against oxidation in plasma in vitro system, and influence on coagulation parameters. The tested extracts showed a scavenging activity of 50-70% of Trolox's power. The OC extract, rich in acteoside, had over 20% better antiradical potential than PR extract which was the only one containing PPGs lacking a B-ring catechol moiety in the acyl unit. Moreover, it was found that only eight tested PPGs demonstrated antioxidant potential in human plasma treated with H2O2/Fe; however, the three tested PPGs possessed anticoagulant potential in addition to antioxidant properties. It appears that the structure of PPGs, especially the presence of acyl and catechol moieties, is mainly related to their antioxidant properties. The anticoagulant potential of these compounds is also related to their chemical structure. Selected PPGs exhibit the potential for treating cardiovascular diseases associated with oxidative stress.

Anti-Platelet Properties of Phenolic and Nonpolar Fractions Isolated from Various Organs of Elaeagnus rhamnoides (L.) A. Nelson in Whole Blood.

Sea buckthorn (Elaeagnus rhamnoides (L.) A. Nelson) is a shrub growing in coastal areas. Its organs contain a range of bioactive substances including vitamins, fatty acids, various micro and macro elements, as well as phenolic compounds. Numerous studies of sea buckthorn have found it to have anticancer, anti-ulcer, hepatoprotective, antibacterial, and antiviral properties. Some studies suggest that it also affects the hemostasis system. The aim of the study was to determine the effect of six polyphenols rich and triterpenic acids rich fractions (A-F), taken from various organs of sea buckthorn, on the activation of blood platelets using whole blood, and to assess the effect of the tested fractions on platelet proteins: fraction A (polyphenols rich fraction from fruits), fraction B (triterpenic acids rich fraction from fruits), fraction C (polyphenols rich fraction from leaves), fraction D (triterpenic acids rich fraction from leaves), fraction E (polyphenols rich fraction from twigs), and fraction F (triterpenic acids rich fraction from twigs). Hemostasis parameters were determined using flow cytometry and T-TAS (Total Thrombus-formation Analysis System). Additionally, electrophoresis was performed under reducing and non-reducing conditions. Although all tested fractions inhibit platelet activation, the greatest anti-platelet activity was demonstrated by fraction A, which was rich in flavonol glycosides. In addition, none of the tested fractions (A-F) caused any changes in the platelet proteome, and their anti-platelet potential is not dependent on the P2Y12 receptor.

Multidirectional effects of saponin fraction isolated from the leaves of sea buckthorn Elaeagnus rhamnoides (L.) A. Nelson.

Many studies show that saponins isolated from various plants have a cytotoxic effect on cancer cells inducing apoptosis and autophagy. On the other hand, saponins also exhibit a number of beneficial properties, such as antioxidant properties. Thus, saponins can be considered both in terms of their therapeutic and protective effects during anticancer treatment. In this study, we investigated the effect of the saponin fraction isolated from sea buckthorn (Elaeagnus rhamnoides (L.) A. Nelson) leaves on the viability of HL-60 cancer cells using resazurin assay and its ability to induction of apoptosis with Annexin V-FITC and propidium iodide (PI) double staining. Moreover, we studied its effect on the oxidative stress induced by H2O2, and anti-platelet and anticoagulant potential in whole blood using T-TAS, a microchip-based flow chamber system. We observed that the saponin fraction significantly decreased the viability of HL-60 cells at the concentration above 50 µg/mL and induced apoptosis at the concentration of 100 µg/mL. Moreover, we observed that saponin fraction used at lower concentrations, such as 0.5 and 1 µg/mL, stimulated HL-60 cells and increased their viability. The saponin fraction also decreased the level of free radicals and reduced oxidative DNA damage measured by the comet assay. However, at high concentration of oxidant H2O2 equal 5 mM, we noticed that the saponin fraction at 50 µg/mL increased the level of free radicals in HL-60 cells. We also demonstrated anticoagulant potential of the saponin fraction at the concentration of 50 µg/mL. Our results indicate that the saponin fraction obtained from sea buckthorn leaves can show both chemotherapeutic and chemoprotective potential.

LC/MS Analysis of Saponin Fraction from the Leaves of Elaeagnus rhamnoides (L.) A. Nelson and Its Biological Properties in Different In Vitro Models.

This study focuses on saponin fraction from sea buckthorn (Elaeagnus rhamnoides (L.) A. Nelson) leaves. It has known that for example teas from sea buckthorn leaves have anti-obesity properties. The objective of our present experiments was to investigate both the chemical composition of saponin fraction, as well as their biological properties in different in vitro models (using human plasma, blood platelets, and peripheral blood mononuclear cells (PBMCs)). We observed that saponin fraction reduces plasma lipid peroxidation and protein carbonylation induced by H2O2/Fe. This fraction also decreased DNA oxidative damage induced by H2O2 in PBMCs. Regarding the cytotoxicity of saponin fraction (0.5-50 µg/mL) none was found to cause lysis of blood platelets, and PBMCs. Our results, for the first time indicate that saponin fraction from sea buckthorn leaves may be a new promising source of compounds for prophylaxis and treatment of diseases associated with oxidative stress.

Response of blood platelets to phenolic fraction and non-polar fraction from the leaves and twigs of Elaeagnus rhamnoides (L.) A. Nelson in vitro.

Sea buckthorn (Elaeagnus rhamnoides (L.) A. Nelson) is a shrub with lanceolate leaves and orange fruits. In traditional Chinese medicine, sea buckthorn organs, especially fruits have been used to treat different diseases, for example cardiovascular disorders. In vitro studies indicate that the phenolic-rich fraction of sea buckthorn fruits demonstrates anti-platelet activity. The aim of the present study was therefore to determine the influence of phenolic and non-polar fractions isolated from the leaves and twigs of sea buckthorn on various parameters of human blood platelets in vitro. Plant material consisted of four different fractions: (1) the phenolic fraction isolated from the leaves, (2) the phenolic fraction isolated from the twigs, (3) the non-polar fraction isolated from leaves and (4) the non-polar fraction from twigs. The chemical composition of the tested fractions was determined using reversed phase UHPLC-HRMS/MS. The fractions from twigs were found to have stronger anti-platelet properties than those from leaves, and all tested fractions were found to be safe for the blood platelets. The tested fractions from the sea buckthorn, especially the non-polar fraction from the twigs, may potentially be a source of compounds with antiplatelet activity.

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.

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.

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.