Yucca Schidigera Bark Research Articles

Comparison of biological activity of phenolic fraction from roots of Alhagi maurorum with properties of commercial phenolic extracts and resveratrol

Phenolic compounds have different biological properties, including antioxidative activities, but they may also be prooxidants. The effect of phenolic fraction from roots of Alhagi maurorum on oxidative protein/lipid damages (determined by such parameters as levels of protein thiol groups and the concentration of thiobarbituric acid reactive species – TBARS) in human blood platelets and human plasma after treatment with hydrogen peroxide – H2O2 (which is the strong biologic oxidant and inflammatory mediator) was studied in vitro. We also studied the effect of A. maurorum extract on blood platelet activation corresponding to thrombin-induced arachidonic acid pathway. Moreover, the present work was designed to study the effect of A. maurorum extract on selected physiological function of blood platelets – adhesion of blood platelets to collagen in vitro. The action of phenolic fraction from A. maurorum was compared with the selected commercial phenolic extracts: extract from berries of Aronia melanocarpa (Aronox®), extract from bark of Yucca schidigera and monomeric polyphenol–resveratrol (3,4′,5-trihydroxystilbene). Exposure of blood platelets or plasma to H2O2 resulted in a decrease of the level of thiol groups in proteins, and an increase of TBARS. In the presence of phenolic fraction from A. maurorum (0.5–50 µg/ml), a reduction of thiol groups oxidation together with the decrease of autoperoxidation of lipids and lipid peroxidation caused by H2O2 or thrombin was observed. The inhibitory, concentration-dependent effects of A. maurorum extract on adhesion of thrombin-activated platelets to collagen were also found. The phenolic fraction from A. maurorum acts as an antioxidant and can be useful as the natural factor protecting against diseases associated with oxidative stress. Tested fraction from A. maurorum has more effective antioxidative activity and antiplatelet properties than aronia extract or other commercial extract, however differences between their actions are not statistically significant.

Qualitative and Quantitative Analysis of Steroidal Saponins in Crude Extract and Bark Powder ofYucca schidigeraRoezl.

Steroidal saponins in commercial stem syrup and in extract of a bark of Yucca schidigera were identified with high-performance liquid chromatography ion trap mass spectrometry and quantitated using ultraperformance liquid chromatography with quadrupole mass spectrometric detection. Fragmentation patterns of yucca saponins were generated using collision-induced dissociation and compared with fragmentation of authentic standards as well as with published spectrometric information. In addition to detection of twelve saponins known to occur in Y. schidigera, collected fragmentation data led to tentative identifications of seven new saponins. A quantitation method for all 19 detected compounds was developed and validated. Samples derived from the syrup and the bark of yucca were quantitatively measured and compared. Obtained results indicate that yucca bark accumulates polar, bidesmosidic saponins, while in the stem steroidal glycosides with middle- and short-length saccharide chains are predominant. The newly developed method provides an opportunity to evaluate the composition of yucca products available on the market.

Influence of Phenolic Constituents from Yucca schidigera Bark on Arachidonate Metabolism in Vitro

Yucca schidigera Roezl. (Agavaceae) has been traditionally used to treat a variety of diseases including arthritis and rheumatism. Phenolic constituents isolated from yucca bark, such as resveratrol, trans-3,3',5,5'-tetrahydroxy-4'-methoxystilbene, and the yuccaols, have been shown to possess various activities in vitro, such as antioxidant, radical scavenging, iNOS expression inhibitory, and platelet aggregation inhibitory effects. In the present study, the influence of a phenolic-rich fraction from yucca bark and of its main phenolic constituents on key enzymes of arachidonate metabolism was investigated. The fraction and the pure phenolics were shown to inhibit COX-1, COX-2, and LTB 4 formation by 5-LOX in vitro to different extents. The degree of COX-1 inhibition was found to be strongly dependent on the substitution pattern of ring B of the stilbenic moiety. The same trend was observed for the COX-2 inhibitory potential, which was, however, in general much lower for the yuccaols as compared with resveratrol. Resveratrol was also the only compound possessing an LTB 4 formation inhibitory activity. The inhibitory activity on key enzymes of arachidonate metabolism observed in this study might contribute to the explanation of the anti-inflammatory and antiplatelet effects observed for Y. schidigera and its phenolic constituents.

Comparative anti-platelet and antioxidant properties of polyphenol-rich extracts from: berries of Aronia melanocarpa, seeds of grape and bark of Yucca schidigera in vitro

The aim of the present study was to investigate and compare the anti-platelet action of extracts from three different plants: bark of Yucca schidigera, seeds of grape and berries of Aronia melanocarpa (chokeberry). Anti-platelet action of tested extracts was compared with action of well characterized antioxidative and anti-platelet commercial monomeric polyphenol–resveratrol. The effects of extracts on platelet adhesion to collagen, collagen–induced platelet aggregation and on the production of in resting platelets and platelets stimulated by a strong platelet agonist–thrombin were studied. The in vitro experiments have shown that all three tested extracts (5–50 µg/ml) rich in polyphenols reduce platelet adhesion, aggregation and generation of in blood platelets. Comparative studies indicate that all three plant extracts were found to be more reactive in reduction of platelet processes than the solution of pure resveratrol. The tested extracts due to their anti-platelet effects may play an important role as components of human diet in prevention of cardiovascular or inflammatory diseases, where blood platelets are involved.

Comparative studies of the antioxidant effects of a naturally occurring resveratrol analogue – trans-3,3′,5,5′-tetrahydroxy-4′-methoxystilbene and resveratrol – against oxidation and nitration of biomolecules in blood platelets

The action of two phenolic compounds isolated from the bark of Yucca schidigera: trans-3,3',5,5'-tetrahydroxy-4'-methoxystilbene and its analogue -- resveratrol (trans-3,4',5-trihydroxystilbene, present also in grapes and wine) on oxidative/nitrative stress induced by peroxynitrite (ONOO(-), which is strong physiological oxidant and inflammatory mediator) in human blood platelets was compared. The trans-3,3',5,5'-tetrahydroxy-4'-methoxystilbene, like resveratrol, significantly inhibited protein carbonylation and nitration (measured by enzyme-linked immunosorbent assay method) in the blood platelets treated with peroxynitrite (0.1 mM) and markedly reduced an oxidation of thiol groups of proteins (estimated with 5,5'-dithio-bis(2-nitro-benzoic acid)] or glutathione (measured by high performance liquid chromatography method) in these cells. The trans-3,3',5,5'-tetrahydroxy-4'-methoxystilbene, like resveratrol, also caused a distinct reduction of platelet lipid peroxidation induced by peroxynitrite. The obtained results indicate that in vitro trans-3,3',5,5'-tetrahydroxy-4'-methoxystilbene and resveratrol have very similar protective effects against peroxynitrite-induced oxidative/nitrative damage to the human platelet proteins and lipids. Moreover, trans-3,3',5,5'-tetrahydroxy-4'-methoxystilbene proved to be even more potent than resveratrol in antioxidative tests. We conclude that the novel tested phenolic compound -- trans-3,3',5,5'-tetrahydroxy-4'-methoxystilbene isolated from Y. schidigera bark possessing Generally Recognized As Safe label given by the Food and Drug Administration and allows their human dietary use -- seems to be a promising candidate for future evaluations of its antioxidative activity and may be a good candidate for scavenging peroxynitrite.

Antioxidant properties of trans-3,3′,5,5′-tetrahydroxy-4′-methoxystilbene against modification of variety of biomolecules in human blood cells treated with platinum compounds

Objective A diet rich in natural antioxidants in combination with anticancer therapy is important in reducing morbidity and mortality in addition to diminishing toxicity and side effects of chemotherapeutic agents. Cisplatin ( cis-diamminedichloroplatinum II, cis-Pt) is a common chemotherapeutic agent, but it causes side effects, including hematologic toxicity with changes in the biological function of blood cells. Methods We compared the action of two phenolic compounds isolated from the bark of Yucca schidigera: trans-3,3′,5,5′-tetrahydroxy-4′-methoxystilbene and resveratrol ( trans-3,4′,5 – trihydroxystilbene, present also in grapes and wine) on oxidative stress induced by cisplatin (used in chemotherapy) and selenium-cisplatin conjugate ([NH 3] 2Pt(SeO 3 [Se-Pt], with a slight toxic effect on blood cells) in human blood platelets and peripheral blood lymphocytes. Results The trans-3,3′,5,5′-tetrahydroxy-4′-methoxystilbene, like resveratrol, significantly inhibited protein carbonylation (measured by enzyme-linked immunosorbent assay and western blot analysis) in blood platelets treated with platinum compounds (10 μg/mL) and markedly reduced oxidation of thiol groups of proteins in these cells. The trans-3,3′,5,5′-tetrahydroxy-4′-methoxystilbene, like resveratrol, caused a distinct reduction of platelet lipid peroxidation induced by platinum compounds. The combined action of the tested phenolic compounds with Se-Pt evoked a significant decrease in DNA damage (measured by the comet assay) in lymphocytes compared with cells treated with Se-Pt only. Conclusion We conclude that one promising natural product may be trans-3,3′,5,5′-tetrahydroxy-4′-methoxystilbene, because it is a stronger antioxidant in the tested models in vitro compared with resveratrol ( P < 0.05). The trans-3,3′,5,5′-tetrahydroxy-4′-methoxystilbene can also be useful as a protective factor against platinum compounds during chemotherapy or cancer prophylaxis.

Relative effects of phenolic constituents from Yucca schidigera Roezl. bark on Kaposi's sarcoma cell proliferation, migration, and PAF synthesis

Yuccaols (A, B, C) are phenolic constituents isolated from Yucca schidigera bark characterized by unusual spirostructures made up of a C 15 unit and a stilbenic portion closely related to resveratrol. These novel compounds are of particular interest for their antioxidant and anti-inflammatory properties. However, their effects on cell proliferation, migration, and platelet-activating factor (PAF) biosynthesis remain unknown. PAF, a potent mediator of inflammation, is known to promote angiogenesis and in vitro migration of endothelial cells and Kaposi's sarcoma (KS) cells. The objective of our study was to determine the effect of Yuccaols and resveratrol on the vascular endothelial growth factor (VEGF)-induced proliferation, migration, and PAF biosynthesis in KS cells. The results indicated that Yuccaols (25 μM) were more effective than resveratrol (25 μM) in inhibiting the VEGF-induced KS cell proliferation. Western blot analysis revealed that Yuccaols reduced the VEGF-induced phosphorylation of p38 and p42/44, thus indicating a possible interference with the mechanism underlying the VEGF-stimulated cell proliferation. Furthermore, Yuccaols completely inhibited the VEGF-stimulated PAF biosynthesis catalyzed by the acetyl-CoA:lyso-PAF acetyltransferase and enhanced its degradation through the PAF-dependent CoA-independent transacetylase (250% of control). In addition, Yuccaol C abrogated the PAF-induced cell motility whereas Yuccaol A and Yuccaol B reduced the cell migration from 7.6 μm/h to 6.1 μm/h and 5.6 μm/h, respectively. These results indicate that the anti-inflammatory properties attributed to Yucca schidigera can be ascribed to both resveratrol and Yuccaols and provide the first evidences of the anti-tumor and anti-invasive properties of these novel phenolic compounds.

Yucca schidigera bark: phenolic constituents and antioxidant activity.

Two new phenolic constituents with unusual spirostructures, named yuccaols D (1) and E (2), were isolated from the MeOH extract of Yucca schidigera bark. Their structures were established by spectroscopic (ESIMS and NMR) analysis. The new yuccaols D and E, along with resveratrol (3), trans-3,3',5,5'-tetrahydroxy-4'-methoxystilbene (4), yuccaols A-C (5-7), yuccaone A (8), larixinol (9), the MeOH extract of Yucca schidigera bark, and the phenolic portion of this extract, were assayed for antioxidant activity by measuring the free radical scavenging effects using two different assays, namely, the Trolox Equivalent Antioxidant Capacity (TEAC) assay and the coupled oxidation of beta-carotene and linoleic acid (autoxidation assay). The significant activities exhibited by the phenolic fraction and its constituents in both tests show the potential use of Y. schidigera as a source of antioxidant principles.

Inhibition of oxidative stress in blood platelets by different phenolics from Yucca schidigera Roezl. bark

Objective We investigated the comparative effects of resveratrol ( trans-3,4′,5-trihydroxystilbene), trans-3,3′,5,5′tetrahydroxy-4′-methoxystilbene, and yuccaols A and C isolated from the bark of Yucca schidigera on oxidative stress in resting blood platelets and blood platelets activated by different agonists (thrombin or thrombin receptor activating peptide). Methods and results Tested phenolics (1–25 μg/mL) reduced, to different degrees, the level of reactive oxygen species measured by the luminol-dependent chemiluminescence and changed the production of O 2 − measured by the reduction of cytochrome c in resting blood platelets. They also inhibited the generation of free radicals in blood platelets activated by thrombin ( P < 0.05) or thrombin receptor activating peptide ( P < 0.05). Treatment of platelets with resveratrol or yuccaols A and C at the concentration of 25 μg/mL increased (statistically non-significant) the level of thiobarbituric acid reactive substances in these cells ( P > 0.05), whereas trans-3,3′,5,5′tetrahydroxy-4′-methoxystilbene and the alcohol yucca extract reduced lipid peroxidation in blood platelets ( P < 0.05). Conclusions Resveratrol and other phenolic compounds from the bark of Yucca schidigera inhibiting free radical generation in blood platelets may be beneficial in protecting against cardiovascular diseases when hyperactivity of platelets is observed.

A Novel Phenolic Spiro Derivative, Yuccaone A, from Yucca schidigera Bark.

A new, very unusual, phenolic constituent based on a spiro benzopyran-4-cyclopentan-3-one system has been isolated from Yucca schidigera bark and its structure has been established by ESI-MS and NMR experiments. In particular the relative configuration of the molecule has been defined combining the NMR data with ab initio conformational studies; the minimum energy conformers for the eight possible diastereomers were compared to the NMR experimental data in order to assess the diastereomer fitting of all the J coupling values and the dipolar values.

A novel phenolic spiro derivative, Yuccaone A, from Yucca schidigera bark

A new, very unusual, phenolic constituent based on a spiro benzopyran-4-cyclopentan-3-one system has been isolated from Yucca schidigera bark and its structure has been established by ESI-MS and NMR experiments. In particular the relative configuration of the molecule has been defined combining the NMR data with ab initio conformational studies; the minimum energy conformers for the eight possible diastereomers were compared to the NMR experimental data in order to assess the diastereomer fitting of all the J coupling values and the dipolar values.

Anti-platelet effects of different phenolic compounds from Yucca schidigera Roezl. Bark

Resveratrol (3,4',5-trihydroxystilbene) has been reported to have a variety of anti-inflammatory, anti-carcinogenic, anti-fungal and anti-platelet effects. It occurs naturally in different medicinal plants. Recently, resveratrol and other related phenolic compounds including trans -3,3',5,5'-tetrahydroxy-4'-methoxystilbene and yuccaols A and C were isolated from the bark of Yucca schidigera . The aim of the present study was to evaluate in vitro the effects of these compounds on platelet aggregation induced by thrombin and ADP. Pretreatment of platelets with resveratrol or other tested phenolics (1-25 w g/ml) slightly reduced platelet aggregation stimulated by 5 w M ADP ( P < 0.05) or 10 w M ADP ( P < 0.005). The comparison of the inhibitory effects of tested compound in thrombin-induced platelet aggregation revealed that phenolic showed even stronger antiplatelet actions than resveratrol. These compounds also had an inhibitory effect on the thrombin-induced enzymatic platelet lipid peroxidation determined as the level of thiobarbituric acid reactive substances.

Resveratrol and Other Phenolics from the Bark ofYuccaschidigeraRoezl.

Five phenolic constituents have been identified in Yucca schidigera bark, and their structures were established by spectral (FABMS and NMR) experiments. These included two known stilbenes, trans-3,4',5-trihydroxystilbene (resveratrol) and trans-3,3',5,5'-tetrahydroxy-4'-methoxystilbene, as well as three novel compounds, yuccaols A, B, and C, with spiro-structures rarely occurring in the plant kingdom. It is suggested that yuccaols A-C are biosynthethized via attachment of a stilbenic derivative to the carbocationic intermediate of the oxidative flavanone-flavonol conversion.