The composition and vascular/antioxidant properties of Taraxacum officinale flower water syrup in a normal-fat diet using an obese rat model.

ETHNOPHARMACOLOGICAL RELEVANCE: Taraxacum officinale (L.), commonly called dandelion has been used for centuries as a natural medicine to treat inflammatory diseases including some metabolic alterations associated with obesity. AIM OF THE STUDY: Based on animal experiments this study aims to explore the potential mechanisms of action of T. officinale flower water syrup (TOFS) together with a normal-fat diet in the intervention of obesity. MATERIALS AND METHODS: Obese male albino-Wistar rats (n = 8) at 25 weeks of age were fed with a normal-fat diet with or without added 27.82% TOFS (w/w) for 4 weeks. The reactivity of thoracic aorta and antioxidant capacity were studied. RESULTS: TOFS delivered daily 926.8 µg of L-chicoric acid, 20.19 µg of luteolin and 3.379 ‬g of sucrose. TOFS showed beneficial effects by regulating blood lipids (HDL, x1.11-fold increase), thereby lowering the risk factors for atherosclerosis (TC/HDL, x0.90-fold). The antioxidant status was improved via an increase in plasma superoxide radical scavenging (SOD, x1.6-fold) and a decrease in lipid peroxidation (MDA, x0.81-fold). Moreover, the following were decreased: Cu (x0.53-fold), Zn (x0.72-fold) and the Cu/Zn molar ratio (x0.60-fold). A marker for liver damage/disease was beneficially decreased (ALP, x0.87-fold). TOFS modulated in a significant way COX-depended relaxation to ACh (p = 0.05) but not to CORM-2 (p = 0.1651) in isolated thoracic arteries, by decreased participation of vasoconstrictor prostanoids. The vascular contraction to prostaglandin F2α was also decreased (x0.62-fold). We observed no change in the feed intake, body weight, organ-to-body weight ratio, blood glucose, CAT, FRAP, AST, ALT, TBARS/carbonyls (in heart, liver, kidneys, spleen) and carbonyls (in blood plasma, thoracic arteries); as well as F2-isoprostanes in urine. Vascular response to the vasodilators ACh, SNP, A23187, CORM-2, pinacidil, NS-1619 and to the vasoconstrictors NA, U-46619, ET-1 as well as hyperpolarizing mechanism(s) were not modified. CONCLUSIONS: TOFS possesses beneficial properties by regulating prostanoids and antioxidant status.

Flavonoid Preparations from Taraxacum officinale L. Fruits-A Phytochemical, Antioxidant and Hemostasis Studies.

Dandelion (Taraxacum officinale L.) roots, leaves, and flowers have a long history of use in traditional medicine. Compared to the above organs, dandelion fruits are the least known and used. Hence, the present paper was aimed at the phytochemical analysis of T. officinale fruit extract and estimating its antiradical, antiplatelet, and antioxidant properties related to hemostasis. Methanolic extract of fruits (E1), enriched with polyphenols (188 mg gallic acid equivalents (GAE)/g), was successfully separated into cinnamic acids (E2; 448 mg GAE/g) and flavonoids (E3; 377 mg GAE/g) extracts. Flavonoid extract was further divided into four fractions characterized by individual content: A (luteolin fraction; 880 mg GAE/g), B (philonotisflavone fraction; 516 mg GAE/g), C (flavonolignans fraction; 384 mg GAE/g), and D (flavone aglycones fraction; 632 mg GAE/g). High DPPH radical scavenging activity was evaluated for fractions A and B (A > B > Trolox), medium for extracts (Trolox > E3 > E2 > E1), and low for fractions C and D. No simple correlation between polyphenol content and antiradical activity was observed, indicating a significant influence of qualitative factor, including higher anti-oxidative effect of flavonoids with B-ring catechol system compared to hydroxycinnamic acids. No cytotoxic effect on platelets was observed for any dandelion preparation tested. In experiments on plasma and platelets, using several different parameters (lipid peroxidation, protein carbonylation, oxidation of thiols, and platelet adhesion), the highest antioxidant and antiplatelet potential was demonstrated by three fruit preparations-hydroxycinnamic acids extract (E2), flavonoid extract (E3), and luteolin fraction (A). The results of this paper provide new information on dandelion metabolites, as well as their biological potential and possible use concerning cardiovascular diseases.

Dietary supplementation with copper nanoparticles influences the markers of oxidative stress and modulates vasodilation of thoracic arteries in young Wistar rats.

We aimed to study the physiological effects of diet supplemented with copper (Cu) nanoparticles (NPs). During the eight weeks of the experiment, young Wistar rats (at seven weeks of age, n = 9) were supplemented with 6.5 mg of Cu either as NPs or carbonate salt (Cu6.5). A diet that was not supplemented with Cu served as a negative control (Cu0). The impact of nano Cu supplementation on lipid (reflected as thiobarbituric acid reactive substances-TBARS) and protein peroxidation (thiol and carbonyl groups) in blood plasma as well as the influence on the vasodilatory mechanism(s) of isolated rat thoracic arteries were studied. Supplementation with Cu enhanced lipid peroxidation (TBARS) in NP6.5 (x2.4) and in Cu6.5 (x1.9) compared to the negative control. Significant increase in TBARS was also observed in NP6.5 (x1.3) compared to the Cu6.5 group. The level of thiol groups increased in NP6.5 (x1.6) compared to Cu6.5. Meanwhile, significant (x0.6) decrease was observed in the Cu6.5 group compared to the negative control. Another marker of protein oxidation, carbonyl groups increased in NP6.5 (x1.4) and Cu6.5 (x2.3) compared to the negative control. However significant difference (x0.6) was observed between NP6.5 and Cu6.5. Arteries from Cu supplemented rats exhibited an enhanced vasodilation to gasotransmitters: nitric oxide (NO) and carbon monoxide (CO). An enhanced vasodilation to NO was reflected in the increased response to acetylcholine (ACh) and calcium ionophore A23187. The observed responses to ACh and CO releasing molecule (CORM-2) were more pronounced in NP6.5. The activator of cGMP-dependent protein kinases (8-bromo-cGMP) induced similar vasodilation of thoracic arteries in NP6.5 and Cu0 groups, while an increased response was observed in the Cu6.5 group. Preincubation with the inducible nitric oxide (iNOS) synthase inhibitor- 1400W, decreased the ACh-induced vasodilation in NP6.5, exclusively. Meanwhile the eicosanoid metabolite of arachidonic acid (20-HETE) synthesis inhibitor-HET0016, enhanced vasodilation of arteries from Cu0 group. In conclusion, this study demonstrates that supplementation with nano Cu influences oxidative stress, which further has modified the vascular response.

Phenolic Fractions from Dandelion Leaves and Petals as Modulators of the Antioxidant Status and Lipid Profile in an In Vivo Study.

Alcoholic leaf and petal fractions of Taraxacum officinale (dandelion) were previously demonstrated to exert in vitro antioxidant and antithrombotic activities in blood plasma and platelets. Eight-week-old male Wistar rats (n = 6) were supplemented for four weeks with dandelion fractions (694 mg/kg of diet = 11.9 ± 0.6 mg daily). Dandelion leaf and petal fractions, which delivered daily 4.10 ± 0.05 and 1.41 ± 0.07 mg l-chicoric acid, respectively, were shown to exert antioxidative actions, measured as decreased levels of thiobarbituric acid-reactive substances (TBARS) in the spleen (≈0.8-fold, leaves and petals), brain (0.53-fold, leaves) and thoracic arteries (0.59-fold, petals). Moreover, petal fraction increased thiols in the blood plasma (1.58-fold), while leaf fraction decreased protein carbonylation levels (0.59-fold). Additionally, dandelion leaf fractions modified the lipid profile: decreased triglyceride (0.44-fold), total cholesterol (0.73-fold), lipoprotein combine index (0.32-fold) and the atherogenic index of plasma (0.62-fold). Dandelion fractions showed a beneficial decrease effect in the participation of cyclooxygenase products in the noradrenaline-induced vascular contractions of thoracic arteries. Meanwhile, only the dandelion leaf fraction augmented acetylcholine-induced vasodilation and upregulated KATP channels. The heart rate and blood pressure were not modified. Dandelion leaf and petal phenolic fractions, enriched with l-chicoric acid, are promising plant materials that may exert in vivo beneficial antioxidant effects.

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.

Comparative phytochemical, cytotoxicity, antioxidant and haemostatic studies of Taraxacum officinale root preparations.

Although the majority of potentially bioactive components of dandelion root have been described, revealing the presence of hydroxycinnamic acids (HCAs) and sesquiterpene lactones (SLs), new compounds are still being discovered, an example of which are the recently characterized 4-hydroxyphenylacetate inositol esters (PIEs). In this work, the dandelion root was separated into five preparations (A-E) differing in chemical content. A detailed LC-MS and chemical investigation of dandelion fractions allowed the identification of about 100 phytochemicals, including new compounds for the genus Taraxacum, and the plant kingdom, such as amino acid-SL adducts. In the DPPH● test, two preparations characterized by high content of HCAs (D and E) showed the highest free radical scavenging activity, while other demonstrated weaker action. In turn, in blood plasma, the best overall protective effect against oxidation by H2O2/Fe was obtained in the presence of preparations A (SL-amino acid adducts enriched fraction) and C (PIEs enriched fraction). A stronger anticoagulant effect was demonstrated for two preparations enriched with HCAs (D and E). None of dandelion root preparations caused the lysis of blood platelets, at all tested range (0.5-50 µg/mL). Our results demonstrate that dandelion roots are a safe and valuable source of different class natural compounds possessing antioxidant, anticoagulant and anti-platelet activities.

Assessment of effects of phenolic fractions from leaves and petals of dandelion in selected components of hemostasis.

Aerial parts and roots of Taraxacum officinale (dandelion) have been found to be rich sources of polyphenols, including cinnamic acid derivatives, flavonoids and triterpenoids, which exert different biological activities, such as anti-inflammatory, anticancer and antimicrobial. Additionally, the whole plant is recognized as safe and well tolerated by humans, with no reported adverse effects. Nowadays, dandelion is a commonly available dietary supplement and a component of pharmaceutical preparations used for the treatment of bladder, liver, and spleen. Nevertheless, the effect of dandelion on blood platelets and plasma - components of hemostasis involved in the functioning of a cardiovascular system and linked with various cardiovascular diseases, has not been studied yet. Thus, the main objective of our in vitro experiments was to examine the anti-platelet and antioxidant properties of four standardized dandelion phenolic fractions, i.e. leaves 50% and 85% methanol fractions, and petals 50% and 85% methanol fractions, in blood platelets. Additionally, aforementioned plant preparations were investigated for hemostatic activity in plasma, using three selected hemostatic parameters: the activated partial thromboplastin time (APTT), prothrombin time (PT) and thrombin time (TT). None of the studied dandelion fractions, caused the damage of human blood platelets, at the whole tested range. The inhibition of lipid peroxidation in platelets treated with H2O2/Fe (the donor of OH) was observed for two fractions: leaves and petals 50% fractions, both at the dose 50 µg/mL. Analysis of the effect on the coagulation activity of human plasma demonstrated that three fractions: petals 50% fraction, and leaves and petals 85% fractions, significantly prolonged the thrombin time, at the whole tested range. On the contrary, none of the fractions changed the APTT and the PT. The obtained results demonstrate that dandelion preparations, based on aerial parts, especially rich in hydroxycinnamic acid derivatives (leaves and petals 50% fractions) are promising plant materials exerting both antioxidant and anticoagulant activities of the hemostatic system that is beneficial in the prevention and treatment of cardiovascular diseases.

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 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.