Browsing by Author "Olas, Beata"

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    A Review of the Biological Activity and Structure–Property Relationships of the Main Compounds from Schisandra chinensis
    (Instytut Uprawy Nawożenia i Gleboznawstwa - Państwowy Instytut Badawczy w Puławach, 2025) Skalski, Bartosz; Kuźniak, Elżbieta; Kowalska, Iwona; Sikora, Monika; Olas, Beata
    Schisandra chinensis is a plant from the Schisandraceae family that grows in humid climates, such as forests and mountain slopes. This plant is attracting the attention of an increasing number of scientists around the world, mainly due to its medicinal properties. It contains a variety of bioactive compounds that exhibit significant biological activities, including lignans, flavonoids, phenolic acids, triterpenoids, organic acids and essential oils. This publication is a review of the latest knowledge and research conducted in the field of analysis of biologically active compounds isolated from Schisandra chinensis.
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    Anti-platelet activity of sea buckthorn seeds and its relationship with thermal processing
    (MDPI, 2024-07-29) Sławińska, Natalia; Żuchowski, Jerzy; Stochmal, Anna; Olas, Beata
    Sea buckthorn (Hippophae rhamnoides L.) is a tree or shrub with small, orange berries. Sea buckthorn seeds have shown many properties beneficial to human health, including antioxidant, anti-hypertensive, anti-hyperlipidemic, and retinoprotective activities. Seeds, as a component of food, are often exposed to high temperatures, which can increase or decrease their biological activity. In our previous study, we showed that both raw and roasted sea buckthorn seeds had significant antioxidant activity, which was measured in human plasma in vitro. In this paper, we evaluated the effect of extracts from raw and roasted sea buckthorn seeds on several parameters of hemostasis in vitro, including thrombus formation in full blood (measured by the Total Thrombus formation Analysis System—T-TAS), blood platelet activation (based on the exposition of P-selectin, the active form of GPIIb/IIIa on their surface and platelet-derived microparticles formation), aggregation (measured with impedance aggregometry), adhesion to fibrinogen and collagen, arachidonic acid metabolism in washed platelets stimulated by thrombin, and COX-1 activity. We also measured the levels of free 8-isoprostane in plasma and the total non-enzymatic antioxidant status of plasma. The extract from roasted seeds (50 µg/mL) significantly prolonged the time of occlusion measured by T-TAS—the AUC10 (area under the curve) value was decreased by approximately 18%. Both extracts decreased the exposition of the active form of GPIIb/IIIa on the surface of platelets activated with 10 μM ADP (by 38.4–62.2%) and 20 μM ADP (by 39.7–51.3%). Moreover, the extract from raw seeds decreased the exposition of P-selectin on the surface of platelets stimulated with 20 μM ADP (by 31.2–34.9%). The adhesion of thrombin-stimulated platelets to fibrinogen and collagen was inhibited only by the extract from roasted sea buckthorn seeds (by 20–30%). Moreover, the extract from raw seeds inhibited the level of TBARS (thiobarbituric acid-reactive substances, an indicator of enzymatic peroxidation of arachidonic acid) in washed platelets stimulated with thrombin; the activity of COX-1 was inhibited by both extracts, although the effect of the extract from raw seeds was stronger. These results indicate that sea buckthorn seeds have anti-platelet activity that is not decreased by thermal processing, but more research is needed to determine which exact chemical compounds and mechanisms are responsible for this phenomenon.
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    Comparative phytochemical, antioxidant, and hemostatic studies of fractions from raw and roasted sea buckthorn seeds in vitro
    (Nature, 2024) Sławińska, Natalia; Żuchowski, Jerzy; Stochmal, Anna; Olas, Beata
    Various seeds, including sea buckthorn (Hippophae rhamnoides L.) seeds, are sources of different bioactive compounds. They can show anti-inflammatory, hypoglycemic, anti-hyperlipidemic, antibacterial, antioxidant, or other biological properties in in vitro and in vivo models. Our preliminary in vitro results have demonstrated that the extracts from raw (no thermal processing) and roasted (thermally processed) sea buckthorn seeds have antioxidant potential and anticoagulant activity. However, it was unclear which compounds were responsible for these properties. Therefore, in continuation of our previous study, the extracts were fractionated by C18 chromatography. Phytochemical analysis of three fractions (a, b, and c) from raw sea buckthorn seeds and four fractions (d, e, f, and g) from roasted sea buckthorn seeds were performed. Several in vitro assays were also conducted to determine the antioxidant and procoagulant/anticoagulant potential of the fractions and two of their major constituents—isorhamnetin 3-O-β-glucoside7-O-α-rhamnoside and serotonin. LC–MS analyses showed that serotonin is the dominant constituent of fractions c and f, which was tentatively identified on the basis of its HRMS and UV spectra. Moreover, fractions c and f, as well as b and e, contained different B-type proanthocyanidins. Fractions b and e consisted mainly of numerous glycosides of kaempferol, quercetin, and isorhamnetin. The results of oxidative stress assays (measurements of protein carbonylation, lipid peroxidation, and thiol groups oxidation) showed that out of all the tested fractions, fraction g (isolated from roasted seeds and containing mainly dihexoses, and serotonin) demonstrated the strongest antioxidant properties.
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    Comparative phytochemical, antioxidant, and hemostatic studies of leaf and stem extracts of Rhazya stricta Decne. in human plasma and human peripheral blood mononuclear cells in vitro
    (Frontiers, 2026-05-11) Hamed, Arafa I.; Mohamed, Amal A. A.; Ben Aissa, Mohamed Ali; Kontek, Bogdan; Kluska, Magdalena; Woźniak, Katarzyna; Kowalczyk, Mariusz; Kowalska, Iwona; Oleszek, Wiesław; Olas, Beata
    Introduction: Rhazya stricta Decne. is considered an important medicinal plant that is rich in secondary metabolites containing anticancer alkaloids. Several indole alkaloid classes have been identified from the various parts of R. stricta, but the cytotoxic potentialities of only a few of these metabolites are known.Methods: In this study, an applied analytical method was used to determine the alkaloids in R. stricta from the stem (RS) and leaf (RL) and their extracts.Results and Discussion: This study tentatively elucidated 10 new compounds of indole alkaloids from the various parts of R. stricta. Among them, six alkaloidal glycosides had not been detected in natural resources. This investigation also examined the in vitro protective results of the four R. stricta stem (A–D) and leaf (A′–D′) extracts, each having a different group of compounds—indole alkaloids, against oxidative stress activated by H2O2/Fe2+ in human plasma in vitro. In addition, we estimated the effect of these plant extracts on DNA fragmentation in human peripheral blood mononuclear cells (PBMCs). Another aim of these in vitro experiments was to determine the result of A–D and A′–D′ on selected hemostatic parameters of human plasma, such as the activated partial thromboplastin time, prothrombin time, and thrombin time, and on the viability of PBMCs. Based on our results, we demonstrate for the first time that tested extracts of the leaves and stems of R. stricta containing different indole alkaloid compounds (especially two tested preparations from R. stricta leaf—C′ and D′) are good antioxidant in vitro models, depending on the dosage, and they may have some promising actions in vivo. For example, we observed a significant difference in the level of DNA damage induced by H2O2 in the experiment with A–D and A′–D′. Two tested extracts from R. stricta leaf (C′ and D′, at all concentrations used) were also found to protect plasma against H2O2/Fe2+—induced lipid peroxidation. In addition, preparation C′ does not induce cytotoxicity. The potential of the metabolomics of extract C′ may be correlated to the presence of rhazisidine, secamine, and their derivatives.
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    Extract from Syringa vulgaris L. Flowers—A Special Emphasis on Its Biological Activity: Evaluation of Antioxidant Properties and Modulation of Coagulation Process in Human Plasma In Vitro
    (MDPI, 2026-03-24) Sławińska, Natalia; Żuchowski, Jerzy; Moniuszko-Szajwaj, Barbara; Skalski, Bartosz; Olas, Beata
    Background/Objectives: Syringa vulgaris L. (common lilac) is one of the most popular ornamental plant species. Through the ages, many parts of S. vulgaris, including fruits, flowers, leaves, and branches, have been used in folk medicine due to their beneficial biological activity. Lilac flowers are the basis of many supplements available on the market. Moreover, its petals and flowers are edible and are an aromatic ingredient in preserves and desserts. However, the data about the antioxidant properties of various parts of S. vulgaris is limited only to the in vitro antioxidant capacity of the extracts—so far, the effect of S. vulgaris flower extract on the parameters of oxidative stress in biological materials, including plasma, has not been demonstrated. Therefore, the aim of our study was to investigate the protective effects of the extract from S. vulgaris L. flowers against oxidative stress in human plasma, and its influence on the coagulation process in vitro. Methods: We measured the levels of three parameters of oxidative stress in human plasma treated with H2O2/Fe2+ (the donor of hydroxyl radicals): lipid peroxidation (based on the level of thiobarbituric acid reactive substances (TBARS)), protein carbonylation, and thiol oxidation. Ascorbic acid (vitamin C) was used as a reference antioxidant. In addition, we studied the effect of the extract on three coagulation parameters of human plasma-activated partial thromboplastin time (APTT), prothrombin time (PT), and thrombin time (TT). We also compared the biological properties of the extract from S. vulgaris flowers with the properties of a phenolic extract from Taraxacum officinalis (dandelion) flowers, as they have proven antioxidant activity in both in vitro and in vivo models and can modulate hemostasis in vitro. Results: Our UHPLC-HRMS analyses of S. vulgaris extract led to a tentative identification of 50 compounds, mainly phenolics and secoiridoids. For the first time, the present study demonstrated that the extract from S. vulgaris flowers (at the concentrations of 1–50 µg/mL) significantly reduced plasma lipid peroxidation and protein carbonylation induced by H2O2/Fe2+. Moreover, the concentrations of 1–25 µg/mL significantly reduced the oxidation of thiol groups in plasma treated with H2O2/Fe2+. The anticoagulant tests also demonstrated that S. vulgaris flowers extract, at physiologically relevant concentrations (1–50 µg/mL), did not affect blood clotting times in vitro, suggesting that it is hemostatically safe. Conclusions: Despite the differences in composition, the extracts from lilac flowers and dandelion flowers exhibited similar protective effects against oxidative damage to human plasma components. However, the extract from S. vulgaris flowers had a stronger inhibitory effect on lipid peroxidation than the extract from dandelion flowers.
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    Fractions from Sea Buckthorn Seeds and Their Bioactive Ingredients as Modulators of Human Blood Platelet Response In Vitro: The Role of Thermal Processing
    (MDPI, 2025-09-27) Sławińska, Natalia; Janko, Luiza; Żuchowski, Jerzy; Olas, Beata
    Background: Given the pivotal role of diet in cardiovascular diseases (CVDs), there is a growing demand for new sources of bioactive phytochemicals that can contribute to CVD prevention and treatment. Previous research has unveiled the cardioprotective properties of several parts of sea buckthorn (Hippophae rhamnoides L.). For example, various fractions isolated from raw and roasted sea buckthorn seeds showed antioxidant properties in vitro. In addition, the serotonin-rich fraction obtained from roasted seed extract had the strongest antioxidant activity. However, it was unclear which chemical constituents contribute to the anti-platelet potential of sea buckthorn seeds. Methods: The anti-platelet activity of two fractions (fraction b and fraction c) from raw sea buckthorn seed extract, two fractions (fraction d and fraction g) from roasted sea buckthorn seed extract, and two chemical compounds - isorhamnetin 3-O-β-glucoside-7-O-α-rhamnoside (a major component of fraction b), and serotonin (5-HT, 5-hydroxytryptamine), present in fraction c was estimated in several in vitro assays. Results: Isorhamnetin 3-O-β-glucoside-7-O-α-rhamnoside significantly inhibited platelet activation. It lowered the exposition of the active form of GPIIb/IIIa on the surface of 20 μM ADP-stimulated platelets by about 26%. It also inhibited the exposition of P-selectin on the surface of 10 and 20 μM ADP-stimulated platelets. In addition, isorhamnetin 3-O-β-glucoside-7-O-α-rhamnoside (at 50 µg/mL) significantly prolonged the time of thrombus formation. The results also indicate that fractions d and g (from roasted seeds) are more effective anti-adhesive factors than fractions from raw sea buckthorn seeds. Conclusions: It can be suggested that sea buckthorn seeds can serve as a new source of anti-platelet compounds (especially derivatives of isorhamnetin) beneficial in CVD prevention and treatment; however, in vivo research is needed to clarify their mechanism of action, physiologically relevant concentrations, and therapeutic potential
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    Phytochemical analysis of the extract from berries of Schisandra chinensis Turcz. (Baill.) and its anti-platelet potential in vitro
    (MDPI, 2025-01-25) Sławińska, Natalia; Kontek, Bogdan; Żuchowski, Jerzy; Moniuszko - Szajwaj, Barbara; Białecki, Jacek; Zakrzewski, Kamil; Bogusz, Paulina; Stochmal, Anna; Olas, Beata
    Schisandra chinensis Turcz. (Baill.) is a dioecious vine belonging to the Schisandraceae family. Its berries show beneficial activities, including cardioprotective, antioxidant, and anti-inflammatory. We examined the chemical content of S. chinensis berry extract and its antiplatelet potential in vitro. The antiplatelet activity assays included measurements of thrombus formation in full blood (with Total Thrombus-formation Analysis System) and platelet activation and adhesion. We also assessed the extract’s effect on coagulation times in human plasma and its cytotoxicity toward blood platelets based on extracellular lactate dehydrogenase activity. The most important constituents of the extract were dibenzocyclooctadiene lignans; schisandrin was the dominant compound. S. chinensis berry extract at the concentration of 50 μg/mL inhibited thrombus formation by approximately 15%. The adhesion of unstimulated and thrombin-activated blood platelets to collagen was inhibited by all used concentrations of the extract (0.5–50 μg/mL), while the adhesion of adenosine diphosphate (ADP)-activated platelets to fibrinogen was inhibited only by the concentrations of 10 and 50 μg/mL. The extract also inhibited the exposition of the active form of GPIIb/IIIa on the surface of platelets stimulated with 10 μM ADP (at 0.5–50 μg/mL) and 20 μM ADP (at 50 μg/mL). The exposition of P-selectin was inhibited only by the extract at the concentrations of 5–50 μg/mL in platelets stimulated with 10 μg/mL collagen. Moreover, the extract was not cytotoxic toward blood platelets. This indicates that S. chinensis berries hold promise as new antiplatelet agents, but more studies are needed to determine their mechanisms of action and in vivo efficiency.