Showing papers on "Verbascoside published in 2009"

Anti-inflammatory phenylpropanoid glycosides from Clerodendron trichotomum leaves.

Abstract: The chromatographic separation of MeOH extract from Clerodendron trichotomum Thunberg leaves led to the isolation of three phenylpropanoid compounds. Using spectroscopic methods, the structures of these compounds were determined as β-(3′, 4′-dihydroxyphenyl)ethyl-O-α-L-rhamnopyranosyl (1→3)-β-D-(4-O-caffeoyl)-glucopyranoside, acteoside (verbascoside) (1), β-(3′, 4′-dihydroxyphenyl)ethyl-O-α-L-rhamnopyranosyl (1→3)-β-D-(6-O-caffeoyl)-glucopyranoside, isoacteoside (2), β-(3′, 4′-dihydroxyphenyl) ethyl-O-α-L-rhamnopyranosyl (1→3)-β-D-glucopyranoside, and decaffeoylacteoside (3). We measured the anti-inflammatory activity of these three phenylpropanoid compounds both in vitro (DPPH Reduction Assay, TBARS Assay on Cu 2+-induced oxidized LDL, PGE2 assay) and in vivo (acetic acidinduced vascular permeability in mice and carrageenan-induced hind paw edema in rats). 80% methanol fraction and acteoside had the activity.

Chemistry and bioactivity of olive biophenols in some antioxidant and antiproliferative in vitro bioassays.

Abstract: The major biophenols in olives and the crude extract and ethyl acetate fraction from olive mill waste were studied for their ability to counteract different stages of oxidative damage, that is, hydrogen peroxide, superoxide radical (SOR), and hydroxyl radical in vitro. Antiproliferative activity on colon cancer (HT-29) and gastric cancer (AGS) cell lines was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide bioassay. Emphasis was given to how the observed in vitro activity is controlled by the structural feature of biophenols and possible synergism and antagonism. While in some bioassays, for example, 2,2'-diphenyl-1-picrylhydrazyl, the nonphenolic moiety had minimal affect, it had a significant role in the SOR scavenging bioassay. Verbascoside was more active than caffeic acid or hydroxytyrosol evaluated individually or in equimolar mixtures in some bioassays. Mixtures of biophenols were more active than individual biophenols as antiproliferative agents. Overall, the mixture of hydroxytyrosol/caffeic acid and the biophenol extracts were more effective in protecting DNA from oxidative damage and inhibiting the growth of cancer cells.

Impact of sampling parameters on the radical scavenging potential of olive (Olea europaea L.) leaves.

Abstract: The impact of sampling parameters, that is, cultivar, leaf age, and sampling date, on the radical scavenging potential of olive leaf extracts was examined via the DPPH• and other assays. Total phenol content was estimated colorimetrically and by fluorometry, whereas phenol composition was assessed by RP-HPLC coupled with diode array, fluorometric, and MS detection systems. Oleuropein was not always the major leaf constituent. Considerable differences noted in individual phenol levels (hydroxytyrosol, oleuropein and other secoiridoids, verbascoside, and flavonoids) among samples were not reflected either in the total phenol content or in the radical scavenging potential of the extracts. It can be suggested that olive leaf is a robust source of radical scavengers throughout the year and that differentiation in the levels of individual components depends rather on sampling period than on cultivar or age. The latter does not present predictable regularity. Exploitation of all types of leaves expected in an ol...

Characterization of olive-leaf phenolics by ESI-MS and evaluation of their antioxidant capacities by the CAT assay

Abstract: Olive leaves are a very abundant vegetable material containing various phenolic compounds, such as secoiridoids and flavonoids, that are expected to exert strong antioxidant capacity. However, little is known about the variation of olive-leaf phenolic composition during maturation and its influence on antioxidant capacity. To answer this question, young and mature Olea Europaea L. leaves were submitted to successive extraction with dichloromethane, ethyl acetate, and methanol, then characterized by ESI-MS. It appeared that mature olive-leaf extracts contained higher levels of verbascoside isomers and glucosylated forms of luteolin, while young ones presented higher contents of oleuropein, ligstroside, and flavonoid aglycones. Moreover, antioxidant capacity evaluation using our newly developed conjugated autoxidizable triene assay showed that, in a lipid-based emulsified system, this phenolic composition variation leads to a change in the ability of extracts to counteract lipid oxidation. Mature olive-leaf extracts exhibit higher antioxidant capacity than young olive-leaf extracts. This result enables us to hypothesize that two main bioconversion scenarios may occur during maturation of olive leaves, which could explain changes observed in antioxidant capacity: (1) a bioconversion of oleuropein and ligstroside into verbascoside isomers and oleuroside, and (2) a bioconversion of flavonoid aglycones into glucosylated forms of luteolin. Finally, this study leads to a better understanding of the relationship between phenolic profile and antioxidant capacity of olive leaves.

Plant Polyphenols Effectively Protect HaCaT Cells from Ultraviolet C–Triggered Necrosis and Suppress Inflammatory Chemokine Expression

Abstract: Oxidative stress is a common response of epidermal cells to a variety of noxious stimuli such as ultraviolet (UV) radiation from solar light and proinflammatory cytokines from skin-infiltrating leukocytes. Here, we report that two types of plant-derived antioxidants, the phenylpropanoid glycoside verbascoside as well as the flavonoids rutin and quercetin possess protective effects against UVC-induced cell damage and proinflammatory activation. The molecules under investigation were effective against the loss of cell integrity associated with necrosis in doses consistent with their antioxidant activity, whereas they did not significantly oppose UVC-induced proliferation arrest and apoptosis. By contrast, only verbascoside effectively inhibited cytokine-induced release of proinflammatory mediators in a dose-dependent fashion. Verbascoside and its homologue teupolioside dramatically impaired NF-κB and AP-1 DNA binding activity. These results suggest that plant polyphenols with antioxidant properties have distinct mechanisms in the suppression of oxidative stress induced in keratinocytes by different stimuli. Verbascoside and teupolioside are hence of potential interest in the protection of the skin from both environmental and inflammatory insults.

Phenylpropanoid production in callus and cell suspension cultures of Buddleja cordata Kunth

Abstract: Plant tissue cultures represent a potential source for producing secondary metabolites. In this work, Buddleja cordata tissue cultures were established in order to produce phenylpropanoids (verbascoside, linarin and hydroxycinnamic acids), as these metabolites are credited with therapeutic properties. Highest callus induction (76.4–84.3%) was obtained in five treatments containing 2,4-Dichlorophenoxyacetic acid (2,4-d: 0.45–9.05 μM) with Kinetin (KIN: 2.32, 4.65 μM), whereas highest root induction (79.6%) corresponded to the α-Naphthaleneacetic acid (9.05 μM) with KIN (2.32 μM) treatment. Verbascoside was the major phenylpropanoid produced in in vitro cultures (root, white and green callus) [66.24–86.26 mg g−1 dry weight (DW)], while linarin and hydroxycinnamic acid production was low (0.95–3.01 mg g−1 DW). Verbascoside and linarin production were improved in cell suspension culture (116 mg g−1 DW and 8.12 mg g−1 DW, respectively).

Anti-inflammatory properties of the plant Verbascum mallophorum.

Abstract: Verbascum mallophorum is part of a large family of Scrophulariaceae consisting of more than 360 species. Verbascum mallophorums contains diverse polysaccharides, iroid glycosides, flavonoids, saponins, volatile oils and phenylentanoids. Verbascum has been used in popular medicine for treating wounds, chilblains, respiratory ailments, acne and arthritic disturbances. Inducible nitric oxide synthase (iNOS) represents one of the three isoforms that produce nitric oxide using L-arginine as a substrate in response to an increase in superoxide anion activated by NF-kappaB. It is implicated in different pathophysiological events and its expression increases greatly during an inflammatory process due to oxidative stress. In our study we reproduced an inflammatory state by treating THP-1 cells (human myelomonocytic leukaemia) with pro-inflammatory stimuli, such as LPS and IFN-gamma, obtaining an up-regulation both in the expression and in the activity of iNOS. The aim of our work is to investigate the possible antiinflammatory action of verbascoside extract from Verbascum mallophorum using a concentration of 100 muM. Our results show a significant decrease in the expression and activity of iNOS and extracellular O2- when cells were treated with verbascoside. Based on these results we hypothesize that verbascoside extract from Verbascum mallophorum has anti-inflammatory properties since it reduces the production of superoxide radicals and consequently reduces the activity of iNOS.

3,4-Dihydroxyphenylglycol (DHPG): an important phenolic compound present in natural table olives.

Abstract: The presence of 3,4-dihydroxyphenylglycol (DHPG) was studied in 32 samples and 10 different cultivars of natural table olives, using an accurate method to avoid wrong quantification. Hydroxytyrosol (HT), tyrosol, and verbascoside were also quantified, as these four compounds comprise the majority of the chromatographic profile. Analyses were carried out by HPLC-DAD-UV after extraction of all phenolics, and hydroxytyrosol was the major component in nearly all samples. High levels of DHPG (up to 368 mg/kg of dry weight) were found in the pulp of natural black olives independent of cultivar and processing method, similar to its concentration in the brine in almost all of the samples. The presented data for this antioxidant indicate that natural table olives are a rich source of DHPG and hydroxytyrosol, compounds with interesting nutritional and antioxidant properties.

Hastatoside and verbenalin are sleep‐promoting components in Verbena officinalis

Abstract: Herbal tea made from Verbena officinalis (V. officinalis) has traditionally been used for the treatment of insomnia and other nervous conditions. In this study, we examined the sleep-promoting activity of hastatoside, verbenalin, and verbascoside, which are the major iridoids (hastatoside and verbenalin) and polyphenol (verbascoside) components responsible for the pharmacological activity of V. officinalis, by electroencephalographic analysis of rats after oral administration of the compounds. Hastatoside (0.64 mmol/kg of body weight) and verbenalin (1.28 mmol/kg of body weight) increased the total time of non-rapid eye movement sleep during a 9-h period from 23.00 to 08.00 hours by 81% and 42%, respectively, with a lag time of about 3–5 h after the administration at 20.00 hours (lights-off time). Both compounds also increased the delta activity during non-rapid eye movement sleep. However, verbascoside had no effect on the amount of sleep. Therefore, hastatoside and verbenalin are major sleep-promoting components of V. officinalis.

Dolichandroside A, a new α-glucosidase inhibitor and DPPH free-radical scavenger from Dolichandrone falcata Seem.

Abstract: A new phenylpropanoid glycoside, dolichandroside-A, together with seven known compounds α-lapachone, lapachol, aloesaponarin II, 8-hydroxydehydroiso-α-lapachone, β-sitosterol, 3,8-dihydroxydehydroiso-α-lapachone and verbascoside were isolated from the active ethyl acetate soluble extract of heartwood of Dolichandrone falcata. All except for dolichandroside-A are known compounds, but have been isolated for the first time from this plant. The structure of all these compounds was determined on the basis of 1D- and 2D-NMR spectral data. All the isolates were tested for α-glucosidase inhibitory and DPPH radical scavenging activity. This is the first report identifying DPPH scavenging activity and α-glucosidase inhibitory activity in D. falcata. Furthermore, along with a new compound, dolichandroside-A, this study also assigns for the first time α-glucosidase inhibitory activity to verbascoside and aloe saponarin-II. Copyright © 2008 John Wiley & Sons, Ltd.

Verbascoside isolated from Lepechinia speciosa has inhibitory activity against HSV-1 and HSV-2 in vitro.

Abstract: Verbascoside has been isolated form L. speciosa after several different chromatographic methods. After its purification, the structure has been unequivocally established using modern spectroscopic techniques. As for the antiviral activity, the maximum non toxic concentration has been established and this concentration has been used in the anti herpes assay, in vitro. Mechanism of action for this molecule regarding the anti-herpes activity has been studied encompassing the following assays: virucidal activity, cellular receptor assay, penetration assay and intracellular assay, in order to understand the activity for this natural product.

Assessment of antioxidant activity of natural extracts

Abstract: The aim of this study was investigate and compare the antioxidant activity of extracts from Labiatae and Oleaceae cell cultures and a natural Verbenaceae extract on pig whole blood. The antioxidant activitiy was assessed using the KRL biological test. Extract obtained from Ajuga reptans (Labiatae) cell cultures and titrated at 50% of phenylpropanoids expressed as teupolioside (T), extract obtained from Siringa vulgaris (Oleaceae) cell cultures and titrated at 50% of phenylpropanoids expressed as verbascoside (V), V and T 50/50 mixture and a natural Verbenaceae extract (NE) titrated at 5% of phenylpropanoids, expressed as verbascoside, were tested for their ability to protects pig red blood cells from 2,2’azobis (2-amidinopropane) dihydrochloride (AAPH) induced hemolysis. The protective effect of the compounds was dose-dependent at concentrations of 0.1 to 1g/L. The active principle in the NE shows an antioxidant activity 2.27 times higher (P<0.01) than the cell culture extract V and 5.11 times higher (P<0.01) than the cell culture extract T. Taking into account the total phenylpropanoids content of cell cultures and natural extract, these results clearly indicate a greater antioxidant activity for the natural Verbaneceae extract.

Phenylethanoid and lignan glycosides from polar extracts of Lantana, a genus of verbenaceous plants widely used in traditional herbal therapies.

Abstract: Many references to the use of Lantana spp. can be found in the ethnopharmacological literature from locations around the globe. This study was focused on examining constituents from the polar extracts of Lantana radula Sw. and Lantana canescens Kunth, for which no prior chemical investigations had been reported. A new phenylethanoid glycoside, raduloside, and lignan glycoside, radulignan, were identified along with the known compounds alyssonoside, arenarioside, calceolarioside E, isonuomioside, samioside, and verbascoside.

Polar Lippia extracts as alternatives for the postharvest control of Guazatine®-resistant strains of Penicillium digitatum in citrus.

Abstract: Introduction . Penicillium digitatum is a commercially important postharvest pathogen of citrus that is responsible for significant annual global losses. Strains of the fungus, which exhibit strong resistance to widely used synthetic fungicides, are of major concern to the industry. The aim of the study was to investigate the antifungal activities of polar extracts and compounds from Lippia species, indigenous to South Africa, against a Guazatine® -resistant strain of P. digitatum. Materials and methods . In vitro tests were done by incorporating the compounds and plant extracts into Malt Extract Agar at concentrations ranging from (0.2 to 1.0) mg·mL–1 . An in vivo (curative) assay was conducted using the checkerboard technique on ‘Valencia’ oranges. Results and discussion . A strong correlation between the in vitro and in vivo results was observed. All the compounds and extracts were able to inhibit fungal growth at concentrations above 0.6 mg·mL–1 . Verbascoside was the most active compound, while extracts of Lippia javanica and Lippia rehmannii caused significant inhibition of mycelial growth. The observed activity was largely ascribed to the presence of verbascoside in the plant extracts. Conclusion . Polar extracts of Lippia species have potential as environmentally friendly alternatives for the control of P. digitatum on citrus.

Synergic combination of phenylpropanoids, such as verbascoside or teupolioside, and mesalamine

Abstract: The present invention relates to the synergic combination of mesalamine with phenylpropanoids (verbascoside or teupolioside), obtained from plant cell cultures, and the pharmacological and nutritional use thereof for the prevention and treatment of inflammatory disorders of the digestive apparatus. In particular, the present invention relates to a pharmaceutical composition containing mesalamine and one or more phenylpropanoids, together with pharmaceutically acceptable excipients.

Mechanism and Polyphenols Involved in the Browning Reaction of Olives

Abstract: The purpose of this work was to disclose the mechanisms of the browning reaction produced on the sur - face of the fresh Manzanilla olive cultivar due to the bruises caused during hand or mechanical harvesting. The role played by the different phenols in the browning reaction and the implication of the enzymes present in the olive flesh have also been studied. The reaction was reproduced in model solutions where olive phenol extracts were put into contact with crude enzymatic olive extracts (active or denaturised) in a solution buffered at the same pH of the olive flesh (5.0) added or not with ascorbic acid to prevent oxidation. The proposed mechanism would consist of two steps. First, there is an enzymatic release of hydroxytyrosol, due to the action of the fruits' β-glucosidases and esterases on oleuropein and hydroxytyrosol glucoside; additional hydroxytyrosol can also be produced (in a markedly lower proportion) by the chemical hydrolysis of oleuropein. In a second phase, hydroxytyrosol and verbascoside are oxidised by the fruits' polyphenoloxidase (mainly) and by a chemical reaction, which occurs to a limited extent due to the olive flesh pH 5.0. This hypothesis of the browning reaction mechanism is in agreement with the results in fresh fruits, because oleuropein is the compound that decreased in a higher proportion when the olives were bruised; and the sum of the concentrations of compounds that contain hydroxytyrosol in its molecule is mainly responsible for the decrease in total phenols in olives.

Antifungal activities of lippia extracts and purified compounds against penicillium digitatum

Abstract: Postharvest decay due to a green mould known as Penicillium digitatum is responsible for significant losses in citrus exports from South Africa. Consumer concerns and stricter trade regulations have put pressure on producers to replace synthetic fungicides used commercially to prevent fungal decay with natural products. A strain was found to be resistant to the commercial fungicide Guazitine isolated from Valencia oranges. The objective of this study was to evaluate the abilities of aqueous extracts of Lippia species indigenous to South Africa (L. javanica, L.scaberrima, L.rehmannii and L. wilmsii) and isolated compounds (theviridoside, verbascoside and isoverbascoside), to inhibit the growth of this resistant strain. In vitro and in vivo tests were conducted to confirm the antifungal activity of each extract and compound. All the compounds and extracts showed significant activities in vitro against the pathogen. Although verbascoside exhibited low activity at low concentrations (0.4 mg.ml-1), its activity increased drastically at concentrations above 0.6 mg.ml-1. It was also observed that, the activities of L. rehmannii and L. javanica were the highest in vitro among the plant extracts. The in vivo results showed that L. javanica was the most potent extract at concentrations greater than 0.6 mg.ml-1. Results of the in vitro and preliminary in vivo studies suggest that employing L. javanica aqueous extracts to control P. digitatum strains resistant to Quazitin worthy of further investigation. Acknowledgements: NRF for funding

Chemical Constituents of Paulownia tomentosa (Thunb.) Steud. var. tomentosa Inner Bark

Abstract: To isolate and identify the chemical constituents of 70% acetone extract from the inner bark of Paulownia tomentosa (Thunb.) Steud. var. tomentosa. The compounds were prepared by Sephadex LH-20 column chromatography repurification supervised under TLC and their structures were identified by physiochemical properties and spectral analyses. Five compounds were isolated and their structures were elucidated as ρ-coumaric acid (Ⅰ),caffeic acid (Ⅱ),verbascoside (Ⅲ),isoverbascoside (Ⅳ) and cistanoside F (Ⅴ). Among the obtained compounds,Ⅰand Ⅱwere phenolic acids,Ⅲ～Ⅴwere epimeric phenylpropanoids,Ⅰ,ⅡandⅤwere isolated for the first time from the title species.