Search results for " Glycosides"

The problem of misidentification between edible and poisonous wild plants: Reports from the Mediterranean area

2018

Abstract Today, in many European countries, people are looking for wild edible plants to experience new tastes and flavors, by following the new trend of being green and environmentally friendly. Young borage and spinach leaves can be easily confused by inexpert pickers with those of other plants, including poisonous ones, such as Mandragora autumnalis Bertol. (mandrake) or Digitalis purpurea L. (foxglove), common in southern and northern Italy respectively. In the last twenty years, several cases of intoxication by accidental ingestion of mandrake and foxglove have been reported. The purpose of this work was to perform a pharmacognostic characterization of young leaves from borage, mandrak…

Differential performance of a specialist and two generalist herbivores and their parasitoids on Plantago lanceolata

2011

The ability to cope with plant defense chemicals differs between specialist and generalist species. In this study, we examined the effects of the concentration of the two main iridoid glycosides (IGs) in Plantago lanceolata, aucubin and catalpol, on the performance of a specialist and two generalist herbivores and their respective endoparasitoids. Development of the specialist herbivore Melitaea cinxia was unaffected by the total leaf IG concentration in its host plant. By contrast, the generalist herbivores Spodoptera exigua and Chrysodeixis chalcites showed delayed larval and pupal development on plant genotypes with high leaf IG concentrations, respectively. This result is in line with t…

The roles of foraging environment, host species, and host diet for a generalist pupal parasitoid

2018

Performance of secondary parasitoids on chemically defended and undefended hosts

2012

Defensive chemicals produced by plants can travel up the food chain by being sequestered by herbivores, and then in turn being sequestered by their parasitoids. Insect species with wide host ranges are predicted to perform poorly in the face of specific chemical defence. However, a species at a high trophic level is expected to have a wide host range. This creates a conflict for hyperparasitoids, many of which depend on specialized hosts. We studied the performance of two hyperparasitoids, Lysibia nana and Gelis agilis, both of which have wide host ranges, on two host species, one chemically defended and the other not. We predicted that both hyperparasitoids would perform better using the u…

Oviposition Cues for a Specialist Butterfly–Plant Chemistry and Size

2008

The oviposition choice of an insect herbivore is based on a complex set of stimuli and responses. In this study, we examined the effect of plant secondary chemistry (the iridoid glycosides aucubin and catalpol) and aspects of size of the plant Plantago lanceolata, on the oviposition behavior of the specialist butterfly Melitaea cinxia. Iridoid glycosides are known to deter feeding or decrease the growth rate of generalist insect herbivores, but can act as oviposition cues and feeding stimulants for specialized herbivores. In a previous observational study of M. cinxia in the field, oviposition was associated with high levels of aucubin. However, this association could have been the cause (b…

Hepatoprotective Effect of Steroidal Glycosides From Dioscorea villosa on Hydrogen Peroxide-Induced Hepatotoxicity in HepG2 Cells

2018

Dioscorea villosa, commonly known as “Wild Yam” and native to North America, is well documented for its pharmacological properties due to the presence of steroidal glycosides. However, the hepatoprotective potential of these compounds has not been studied so far. The present investigation was aimed to study the hepatoprotective effect of the steroidal glycosides from D. villosa against H2O2, a known hepatotoxin, in human liver cell line (HepG2). Cytotoxicity assessment was carried out in cells exposed to various concentrations (10–50 μM) of compounds for 24 h using MTT assay and morphological changes. All tested compounds were known and among them, spirostans (zingiberensis saponin I, diosc…

Dietary intake and major food sources of polyphenols in people with type 2 diabetes: The TOSCA.IT Study

2018

Purpose: Proper evaluation of polyphenols intake at the population level is a necessary step in order to establish possible associations with health outcomes. Available data are limited, and so far no study has been performed in people with diabetes. The aim of this work was to document the intake of polyphenols and their major food sources in a cohort of people with type 2 diabetes and in socio-demographic subgroups. Methods: We studied 2573 men and women aged 50–75 years. Among others, anthropometry was measured by standard protocol and dietary habits were investigated by food frequency questionnaire (EPIC). The intake of polyphenols was evaluated using US Department of Agriculture and Ph…

Dose-response relationships and plasma concentrations of digitalis glycosides in man.

1978

An inter-individual, randomized, double-blind study of digitoxin (Dt) and β-acetyl digoxin (D) was performed in 120 healthy male volunteers. Groups of 10 persons each received orally D 0, 0.1, 0.2, 0.3, 0.4, 0.5 or 0.6 mg and Dt 0.04, 0.08, 0.12, or 0.16 mg daily for 7 days; Loading doses were given for the first three days. Plasma levels were measured with an86Rb-erythrocyte assay 24 h after the last dose. ECG, carotid artery pulse and phonocardiogram were recorded prior to (b) and 24 h after (a) the last dose. QTc, amplitude of T-waves in V2 to V6, electromechanical systole (QS2c) and left ventricular ejection time (LVETc) were measured. The differences between a and b (Δ-values) reflect …

The effect of cathartic agents on transmucosal electrical potential difference in the human rectum.

1980

Active ion transport in the colon is generating a transmucosal electrical potential difference (PD) of about 40 mV. Cathartic agents inhibit electrolyte and water net-absorption or cause net-secretion which should be reflected in a change of PD. In 83 normal subjects the effect of an isotonic eletrolyte solution (control) and different cathartic agents on rectal PD was tested: Laxatives (bisacodyl, rhein), bile acids (cholic and deoxycholic acid), fatty acids (oleic and ricinoleic acid) and cardiac glycosides (meproscillarin, digitoxin, digoxin). Bisacodyl, deoxycholic acid in high concentration, meproscillarin and digitoxin significantly decreased PD, while the other substances did not. Ca…

Natural Triterpene Glycosides for Antibody Recognition

2016

Multiple sclerosis is an autoimmune disease that affects the central nervous system. The key role of the glycosylation in disease pathogenesis has been previously studied and the synthetic N-glucosylated peptide CSF114(Glc) proved its efficiency in autoantibody recognition in the sera of multiple sclerosis patients. Herein, pure natural triterpene glycosides containing different glycosyl moieties were isolated and tested in multiple sclerosis patientsʼ sera to better understand the role of glycosylation. They were selected taking into account the nature and complexity of their osidic part. Five triterpene glycosides were isolated from several plants with more than 95 % purity. The interacti…