iridoids and echinacoside

Chronic hyperalgesia and allodynia associated with progressive damage of peripheral neurons are the most prevalent complications of diabetes mellitus. Plants belonging to the family of Oleaceae were traditionally used in folk medicine for the management of diabetes.. The aim of this study was to investigate whether an aqueous extract from the leaves of Ligustrum vulgare (common privet) could be useful to target neuropathic pain in a rat streptozotocin (STZ) model of diabetes.. The chemical composition of the aqueous extract from privet leaf was characterized with the UHPLC-DAD-MS method and the analytical quantification of its constituents was performed with HPLC-DAD. Mechanical hyperalgesia and allodynia were evaluated with the Randall-Selitto and von Frey tests.. Our investigation revealed the presence of secoiridoids: oleacein (23.48 ± 0.87 mg/g), oleocanthal (8.44 ± 0.08 mg/g), oleuropein (1.50 ± 0.01 mg/g), as well as phenylpropanoids: echinacoside (6.46 ± 0.07 mg/g), verbascoside (4.03 ± 0.04 mg/g) and p-coumaroyl glucarates in the dried aqueous extract of privet leaves. Behavioral data indicated that chronic intraperitoneal administration of the extract (50-200 mg/kg) for 21 days resulted in a decrease in diabetes-induced hyperalgesia and allodynia. Blood glucose levels remained unaltered, while body weight and water intake decreased significantly.. The aqueous privet leaf extract could serve useful in facilitating treatment of painful diabetic neuropathy. Additionally, the study showed that the antihyperalgesic activity of Ligustrum vulgare leaf extract is not likely related to its antihyperglycemic properties.

Topics: Aldehydes; Animals; Chromatography, High Pressure Liquid; Cyclopentane Monoterpenes; Diabetes Mellitus, Experimental; Diabetic Neuropathies; Glucosides; Glycosides; Hyperalgesia; Iridoid Glucosides; Iridoids; Ligustrum; Male; Neuralgia; Phenols; Plant Extracts; Plant Leaves; Rats; Streptozocin

We report the first analysis in absolute, and in particular, concerning the phytochemical pattern, about an endemic Italian species, Ajuga tenorei C. Presl. The analysis, performed by means of techniques such as Column Chromatography and NMR spectroscopy and Mass spectrometry, led to the isolation and the identification of five compounds namely verbascoside (1), echinacoside (2), ajugoside (3), harpagide (4) and 8-O-acetylharpagide (5). The presence of these compounds is important from both chemotaxonomic and ethno-pharmacological point of view. For what concerns the first point is confirmed the correct botanical classification of the species. The isolated compounds are also known to exert peculiar pharmacological activities and their presence may give a rationale to the historical medicinal properties associated to the Ajuga genus in general, since these plants have a long traditional use in many parts of the world. Such fact might suggest the use of also this species in this sense.

Topics: Ajuga; Glucosides; Glycosides; Iridoid Glycosides; Iridoids; Italy; Mass Spectrometry; Phenols; Plant Components, Aerial; Plant Extracts; Plants, Medicinal; Pyrans

In this study, we report the first phytochemical analysis of polar fraction of Pedicularis kerneri Dalla Torre growing in Dolomites, Italy. Several iridoid glucosides were isolated, namely aucubin (1), monomelittoside (2), plantarenaloside (3), euphroside (4), mussaenosidic acid (5) and 8-epiloganic acid (6), showing a composition in accordance with previous study on this genus. The studied samples, collected from Dolomites, presented a chemotype already recognised in species from North America, characterised by euphroside (4) and aucubin (1) as main components, but the main character was the presence of monomelittoside (2) never reported in this genus. The identification of verbascoside (7), leucosceptoside A (9) and echinacoside (10) complete the systematic framing of this species since is ascertained the co-occurrence of phenylethanoid glycosides with iridoids in Lamiales species.

Topics: Glucosides; Glycosides; Iridoid Glucosides; Iridoids; Italy; Molecular Structure; Pedicularis; Phenols; Plant Extracts

In our continued investigation of plants from the family Oleaceae we have now investigated Picconia azorica endemic to the Azores. Like most species within the family it contains the oleoside-based secoiridoid glucosides ligstroside and oleuropein as the main compounds and in addition verbascoside and echinacoside. As with the previously investigated Picconia excelsa, it also contained the carbocyclic iridoid glucosides involved in the biosynthetic pathway to the oleoside derivatives. However, while P. excelsa contained loganin esterified with some monoterpenoid acids, P. azorica contains similar esters of 7-epi-loganic acid named Picconioside A and B. In addition were found the two 7-O-E/Z-cinnamoyl esters of 7-epi-loganic acid named Picconioside C and D.

Topics: Azores; Glucosides; Glycosides; Iridoid Glucosides; Iridoids; Molecular Structure; Oleaceae; Phenols; Pyrans

The aim of the study was a HPLC evaluation of the lipoxygenase activity inhibiting activity of a water infusion of Ligustrum vulgare L. leaves and selected isolates from it. The antiradical activity of the water infusion was determined using DPPH, ABTS and FRAP tests. Oleuropein and echinacoside concentrations in the water infusion were determined by HPLC. Water infusion, echinacoside and oleuropein were used for an antilipoxygenase activity assay using lipoxygenase isolated from rat lung cytosol fraction. Activity of 8-LOX, 12-LOX and 15-LOX were monitored through formation of 8-HETE, 12-HETE and 15-HETE, respectively. The water infusion exhibited the highest activity against all lipoxygenases, followed by oleuropein. Echinacoside was ineffective against LOXs in lower concentrations, while higher concentration showed similar inhibition on 8-LOX and 12-LOX. 15-LOX was affected more and the presence of echinacoside remarkably decreased its activity.

Topics: Animals; Anti-Inflammatory Agents; Chromatography, High Pressure Liquid; Cytosol; Glycosides; Hydroxyeicosatetraenoic Acids; Iridoid Glucosides; Iridoids; Ligustrum; Lipoxygenase; Lipoxygenase Inhibitors; Lung; Medicine, Traditional; Plant Extracts; Plant Leaves; Pyrans; Rats

A new method based on the inhibitory effects of antioxidants on the oscillations of the hydrogen peroxide, acidic iodate, malonic acid, and Mn(II)-catalyzed system (known as the Briggs-Rauscher reaction), was used for the evaluation of antioxidative capacity. With this method, which works near the pH of the fluids in the stomach (pH approximately 2), a group of natural compounds present in fruits and vegetables or in medicinal plants assumed to have antioxidant capacity, was tested successfully. The aim of the present study is to evaluate the antioxidative properties of some active principles contained in vegetables and aromatic plants, namely, cynarin (from Cynara scolymus), rosmarinic acid (from Rosmarinus officinalis), echinacoside (from Echinacea species), puerarin (from Pueraria lobata), and oleuropein (from Olea europea). Also studied with the Briggs-Rauscher reaction method was the antioxidant activity of cyanidin 3-O-beta-glucopyranoside (from Citrus aurantium) in order to compare the results with those obtained by other methods. The conclusions on the dependency of the antioxidative activity on the pH of the testing system are given.

Topics: Antioxidants; Cinnamates; Cynara; Depsides; Echinacea; Flavonoids; Fruit; Glycosides; Hydrogen Peroxide; Hydrogen-Ion Concentration; Iodates; Iridoid Glucosides; Iridoids; Isoflavones; Malonates; Manganese; Olea; Phenols; Plants, Medicinal; Polymers; Pueraria; Pyrans; Rosmarinic Acid; Rosmarinus; Vegetables