Search results for "Iridoid"

A one step enhanced extraction and encapsulation system of cornelian cherry (Cornus mas L.) polyphenols and iridoids with β-cyclodextrin

2021

Abstract The objective of this study was simultaneous extraction and encapsulation of cornelian cherry active principles. As an encapsulating agent, β-cyclodextrin (β-CD) was used to enhance the ultrasound-assisted extraction of cornelian cherry polyphenols and iridoids. Lyophilized cornelian cherry fruit was extracted by four different solvents: pure water, 50% aqueous ethanol (conventional system), 1.5% β-CD water solution and 1.5% β-CD aqueous ethanol solution. The highest enhancement of the extraction efficiency was observed for flavonoids and anthocyanins, especially for cyaniding 3-galactoside and pelargonidin 3-galactoside. Water-ethanolic extract was used to form inclusion complexes…

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…

Halloysite nanotubes as a carrier of cornelian cherry (Cornus mas L.) bioactives

2020

Abstract Cornelian cherry fruit extract rich in anthocyanins and iridoids was encapsulated in the halloysite nanotubes in order to obtain a stable nanoscale system for better delivery and prolonged release of bioactive constituents. The cyclic vacuum technique was used for halloysite nanotubes-cornelian cherry composite preparation and the loading of 8.5 wt% was achieved. Pure cornelian cherry extract exhibited antiproliferative effect on HT-29, MCF7, and MRC-5 cells, pristine halloysite nanotubes affected the growth of MCF7 cells, while halloysite nanotubes-cornelian cherry composites demonstrated proliferative activity in all tested cells. The sustained release of anthocyanins was achieve…

Effects of oleuropein on tumor cell growth and bone remodelling: Potential clinical implications for the prevention and treatment of malignant bone d…

2020

Oleuropein (Ole) is the main bioactive phenolic compound present in olive leaves, fruits and olive oil. This molecule has been shown to exert beneficial effects on several human pathological conditions. In particular, recent preclinical and observational studies have provided evidence that Ole exhibits chemo-preventive effects on different types of human tumors. Studies undertaken to elucidate the specific mechanisms underlying these effects have shown that this molecule may thwart several key steps of malignant progression, including tumor cell proliferation, survival, angiogenesis, invasion and metastasis, by modulating the expression and activity of several growth factors, cytokines, adh…

PTP1B phosphatase as a novel target of oleuropein activity in MCF-7 breast cancer model.

2019

Phosphatase PTP1B has become a therapeutic target for the treatment of type 2-diabetes, whereas recent studies have revealed that PTP1B plays a pivotal role in pathophysiology and development of breast cancer. Oleuropein is a natural, phenolic compound with anticancer activity. The aim of this study was to address the question whether PTP1B constitutes a target for oleuropein in breast cancer MCF-7 cells. The cellular MCF-7 breast cancer model was used in the study. The experiments were performed using cellular viability tests, Elisa assays, immunoprecipitation, flow cytometry analyses and computer modelling. Herein, we evidenced that the reduced activity of phosphatase PTP1B after treatmen…

Chemopreventive effect of oleuropein in colitis-associated colorectal cancer in c57bl/6 mice

2015

Scope The main phenolic secoiridoid oleuropein and active constituent from olive tree (Olea europaea, Oleaceae), has demonstrated anti-inflammatory properties in intestinal inflammation and anti-tumoral effects in different cancer cells. In this study, we evaluated the chemoprevention of oleuropein in a model of azoxymethane (AOM)/Dextran sulfate sodium (DSS)-induced colorectal cancer (CRC) in C57BL/6 mice and the modulatory effect on the Th17 response in DSS acute colitis. Methods and results Oleuropein protected from AOM/DSS-induced CRC by improving clinical symptoms, disease activity index score as well as suppressed the growth and multiplicity of colonic tumors. Treatment with oleuropei…

Potential Uses of Olive Oil Secoiridoids for the Prevention and Treatment of Cancer: A Narrative Review of Preclinical Studies

2021

The Mediterranean diet (MD) is a combination of foods mainly rich in antioxidants and anti-inflammatory nutrients that have been shown to have many health-enhancing effects. Extra-virgin olive oil (EVOO) is an important component of the MD. The importance of EVOO can be attributed to phenolic compounds, represented by phenolic alcohols, hydroxytyrosol, and tyrosol, and to secoiridoids, which include oleocanthal, oleacein, oleuropein, and ligstroside (along with the aglycone and glycosidic derivatives of the latter two). Each secoiridoid has been studied and characterized, and their effects on human health have been documented by several studies. Secoiridoids have antioxidant, anti-inflammat…