59 research outputs found

    Interaction of quercetin, cyanidin, and their O-glucosides with planar lipid models: implications for their biological effects

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    Flavonoids are specialized metabolites produced by plants, as free aglycones or as glycosylated derivatives, which are particularly endowed with a variety of beneficial ealth properties. The antioxidant, anti-inflammatory, antimicrobial, anticancer, antifungal, antiviral, anti-Alzheimer’s, anti-obesity, antidiabetic, and antihypertensive effects of flavonoids are now known. These bioactive phytochemicals have been shown to act on different molecular targets in cells including the plasma membrane. Due to their polyhydroxylated structure, lipophilicity, and planar conformation, they can either bind at the bilayer interface or interact with the hydrophobic fatty acid tails of the membrane. The interaction of quercetin, cyanidin, and their O-glucosides with planar lipid membranes (PLMs) similar in composition to those of the intestine was monitored using an electrophysiological approach. The obtained results show that the tested flavonoids interact with PLM and form conductive units. The modality of interaction with the lipids of the bilayer and the alteration of the biophysical parameters of PLMs induced by the tested substances provided information on their location in the membrane, helping to elucidate the mechanism of action which underlies some pharmacological properties of flavonoids. To our knowledge, the interaction of quercetin, cyanidin, and their O-glucosides with PLM surrogates of the intestinal membrane has never been previously monitored

    Nematicidal Potential of Sulla (<i>Hedysarum coronarium</i> L.) against the Root-Knot Nematode <i>Meloidogyne incognita</i>

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    The content of nematicidal metabolites such as saponins, flavonoids and tannins in sulla (Hedysarum coronarium L.) suggests its potential nematicidal activity. In this study, the biocidal activity of 62.5–1000 ÎŒg mL−1 concentrations of flavonoid and tannin fractions from sulla was assessed in in vitro assays on the infective juveniles (J2) of the root-knot nematode (RKN) Meloidogyne incognita, while the suppressive effects of soil amendments with 10–40 g kg−1 soil rates of sulla biomass were investigated on potted tomato infested by M. incognita. The content of total nitrogen, carbon, flavonoids, tannins and saponins of sulla experimental material was also determined. After a 96-h exposure, more than 80% of the M. incognita J2 were killed even by a 125 ”g mL−1 concentration of the flavonoid extract, while mortality peaked at 89% only at the 1000 ”g mL−1 concentration of the tannin solution. Soil incorporation with sulla biomass significantly reduced the M. incognita densities both on tomato roots and in the soil, compared to either the non-treated control and chemical treatment with Fluopyram. The data confirmed the nematicidal potential of sulla, mainly due to its content of flavonoids and tannins, suggesting its suitability as green manure or a soil amendment for sustainable RKN management

    Antioxidant activity and protective effect of the outer scales hydroalcoholic extract of Allium cepa L. var. Tropea on toxicity damage induced by Cadmium in Caco-2 cells

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    The characterization of bioactive metabolites and the protective effects against Cadmium (Cd) of the hydroalcoholic extract from Allium cepa var. Tropea (Tropea red onion) in human Caco-2 colon adenocarcinoma cells and in vitro antioxidant effects were investigated. Tropea red onion extract showed high levels of bioactive compounds and a strong activity as radical scavenger and inhibitor of lipid peroxidation. The most abundant specialized metabolites were quercetin derivatives. In addition, the extract inhibited NO release in a dosedependent manner. Exposure of Cd treated human Caco-2 cells to the Tropea red onion extract resulted in a higher cytoprotection with a significant falloff of cells damage produced by Cd. The effect of Tropea red onion evaluated with the MTT assay and LDH test, was time-dependent and more evident after 24h of treatment. Caco-2 cells treated with the Tropea red onion extract and CdCl2 at 24h showed a significant cytoprotection at concentrations equal to 50 ÎŒg/mL + 25 ÎŒM and 100 ÎŒg/mL + 25 ÎŒM while at 72h at a concentration of 25 ÎŒg/mL + 25 ÎŒM. We observed with MTT and LDH assays that treatment of cells with Tropea red onion extract at 24h was able to significantly prevent Cd-induced cytotoxicity alon

    Relationship between Chemical Composition and Nematicidal Activity of Different Essential Oils

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    In this study, the relationship between nematicidal activity and chemical composition of ten essential oils (EOs) from different plant species was investigated both in in vitro assays on juveniles (J2) and eggs of the root-knot nematode Meloidogyne incognita and in experiments on tomato in soil infested by M. incognita. Nematode J2 were exposed for 4, 8 or 24 h to 0.78–100 ÎŒg mL−1 concentrations of each EO, whereas 24, 48 or 96 h exposures to 250, 500 and 1000 ÎŒg mL−1 solutions were tested on M. incognita egg masses. Treatments with 50, 100 or 200 ÎŒg kg soil rates of each EO were applied in the experiment on potted tomato. The highest nematicidal potential resulted for the C. verum EO, as highly toxic to both M. incognita J2 and eggs and strongly suppressive on nematode multiplication on tomato roots. The infestation of M. incognita on tomato roots was also strongly reduced by the EOs from E. citriodora and S. aromaticum, both highly toxic to M. incognita J2 but less active on nematode eggs. Adversely, R. graveolens EO strongly inhibited the egg hatch but was limitedly toxic to the infective J2. Chemical composition of the EOs was determined by GC-FID and GC-MS. The ten EOs showed a very different chemical composition in terms of major phytochemicals, with one or two dominant components totally amounting up to 85%. The structure–activity relationship based on the main phytochemicals identified in the assayed EOs and their nematicidal effects on M. incognita was also discussed. Results from this study confirmed that the selection of suitable EO raw materials can lead to the formulation on new effective nematicidal products. Keywords: essential oils; bioactive components; nematicidal activity; Meloidogyne incognita

    Lobularia maritima (L.) Desv. Aerial Parts Methanolic Extract: In Vitro Screening of Biological Activity

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    Abstract: Lobularia maritima (L.) Desv. is a perennial herb growing wild in the Mediterranean basin. The aim of this work was to assess the fatty acid, terpene, phytosterol, and phenolic composition of the methanolic extract and its sub‐fractions using Gas Chromatography‐Mass Spectrometry (GCMS), High‐Performance Liquid Chromathography with Dioide‐Array Detector (HPLC‐DAD), High‐Performance Liquid Chromathography‐High Resolution Mass Spectrometry (HPLC‐HRMS), and Electrospray Ionization Tandem Mass Spectrometry (ESI‐MS/MS). The potential health benefits of this plant species have been investigated as well. The antioxidant activity was determined in vitro by means of 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) and ÎČ‐carotene bleaching tests. The inhibitory potential towards the production of the pro‐inflammatory mediator nitric oxide was verified on lipopolysaccharide (LPS)‐stimulated murine macrophage RAW 264.7 cell line. A remarkable inhibitory activity was observed for the dichloromethane fraction, with an IC50 value equal to 45.86 ± 1.05 ÎŒg/mL, a significant result if compared to indomethacin and the known nitric oxide synthase inhibitor NG‐nitro‐L‐arginine methyl ester (L‐NAME), used as positive controls. Moreover, the ethyl acetate fraction proved to be effective in inhibiting pancreatic lipase, an enzyme that plays a pivotal role in the gastrointestinal digestion of dietary fat, suggesting that this species could potentially be a promising source of useful compounds for the treatment of obesity

    Activity of Saponins from Medicago Species against phytoparasitic nematodes

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    Abstract: Content of bioactive saponins of Medicago species suggests that they may also exert, as previously demonstrated on M. sativa, nematicidal properties exploitable for the formulation of new products for sustainable phytoparasitic nematode management. This study was addressed to highlight the bioactivity of saponins from five dierent Medicago species still poorly known for their biological ecacy, i.e., M. heyniana, M. hybrida, M. lupulina, M. murex and M. truncatula, against the plant parasitic nematodes Meloidogyne incognita, Xiphinema index and Globodera rostochiensis. The bioactivity of the extracts from the five Medicago species was assessed by in vitro assays on the juveniles (J2) and eggs of M. incognita and G. rostochiensis and the adult females of X. index. The suppressiveness to M. incognita of soil treatments with the Medicago plant biomasses was also investigated in a tomato experiment. The nematicidal activity of the five Medicago species was reported and discussed in relation to their phytochemical profile

    Polyphenol content and bioactivity of Achillea moschata from the Italian and Swiss Alps

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    Abstract: Achillea moschata Wulfen, which grows in the Alps, is extensively used by local people for its medicinal properties. Two studied samples were collected, at the flowering stage, in Val Mustair (Switzerland) and Valchiavenna (Italy), respectively. The aerial parts were defatted with petroleum ether (PET) and successively extracted with dichloromethane (DCM) and methanol (MeOH). High-performance liquid chromatography and electrospray ionization-tandem mass spectrometry analyses of the methanolic extracts evidenced that flavonoids were the predominant compounds compared to phenolic acids in both samples (89.5 vs. 33.0 ÎŒg/mg DW in A. moschata Valchiavenna and 82.5 vs. 40.0 ÎŒg/mg DW in A. moschata Val Mustair). Among flavonoid derivatives, luteolin and apigenin were the predominant aglycones, free and glycosilated. The A. moschata Valchiavenna extract was characterized by apigenin as the main compound (60.4 ÎŒg/mg DW), while A. moschata Val Mustair was characterized by its derivative apigenin 7-O-glucoside (44.7 ÎŒg/mg DW). The antioxidant activity of all the obtained extracts was tested by the DPPH (2,2-diphenyl-picryl hydrazyl) and ABTS (2,21-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) methods, which showed their increasing scavenger capacity in relation to extract polarity (PET extract &lt; DCM extract &lt; MeOH extract). The extracts were also investigated against three Gram-positive (Bacillus cereus, Enterococcus faecalis and Staphylococcus aureus) and three Gram-negative (Escherichia coli, Proteus mirabilis and Pseudomonas aeruginosa) bacterial species using the disc diffusion assay. DMC and PET were the most active extracts (inhibition diameter: ≄12 mm)

    Nematicidal activity of Echinacea species on the root‑knot nematode Meloidogyne incognita

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    Echinacea species are reported for a large content of bioactive compounds, but their effects on phytoparasitic nematodes are still unknown. This study comparatively investigated the in vitro activity of chemically characterized extracts from E. angustifolia, E. pallida and E. purpurea on juveniles and eggs of the root-knot nematode Meloidogyne incognita. Suppressiveness of soil amendments with Echinacea plant biomasses was also investigated against M. incognita on tomato in potting mixes. More than 50% juvenile mortality occurred after a 48-h exposure to a 500 ÎŒg mL−1 solution of all Echinacea extracts, as well as more than 50% of M. incognita eggs did not hatch after a 1-week exposure to the same concentration of E. angustifolia extracts. Nematode multiplication on tomato roots was always significantly reduced in soil amended with all Echinacea biomasses, as well as almost all treatments also resulted in a significant tomato growth increase. Polar compounds such as echinacoside and chicoric acid were the main components of the extracts from Echinacea aerial parts, whereas apolar components as alkamides prevailed in root extracts. Data confirmed the potential of the three Echinacea species, mainly E. angustifolia, for the formulation of new formulates for a sustainable nematode management

    Triterpenic saponins from Medicago marina L.

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    The saponin composition of leaves and roots from Medicago marina L., sea medic, was investigated by a combination of chromatographic, spectroscopic and spectrometric (GC, LC, ESI-MS/MS, NMR) methods. Several compounds were detected and quantified by HPLC using the external standard method. Saponins from this plant species consist of a mixture of high molecular weight bidesmosidic derivatives of medicagenic and zanhic acid, containing up to six sugars in the molecules. Six of the detected saponins were previously isolated and reported as constituents of other Medicago spp.; one saponin was previously described in other plant species; four saponins are undescribed compounds in Medicago and never reported before in other plant species. These are: 3-O-ÎČ-Dglucopyranosyl-( 1→2)-ÎČ-D-glucopyranosylzanhic acid 28-O-ÎČ-D-xylopyranosyl-(1→4)-[ÎČ-D-apiofuranosyl- (1→3)]-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl ester; 3-O-ÎČ-D-glucopyranosyl-(1→2)-ÎČ-D-glucopyranosylzanhic acid 28-O-ÎČ-D-xylopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl ester; 3-O-ÎČ-D-glucopyranosyl-(1→2)-ÎČ-D-glucopyranosylmedicagenic acid 28-O-ÎČ-D-xylopyranosyl-(1→4)-[α-L-arabinopyranosyl-( 1→3)]-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl ester and 3-O-ÎČ-D-glucopyranosylmedicagenic acid 28-O-ÎČ-D-xylopyranosyl-(1→4)-[α-L-arabinopyranosyl-(1→3)]-α-L-rhamnopyranosyl- (1→2)-α-L-arabinopyranosyl ester. The specific saponins synthesized by M. marina may have a role in its tolerance to environment, representing a reservoir of osmolytic sugars
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