Search results for "Catechin"

ADAM10 in Alzheimer's disease: Pharmacological modulation by natural compounds and its role as a peripheral marker.

2019

Abstract Alzheimer’s disease (AD) represents a global burden in the economics of healthcare systems. Amyloid-β (Aβ) peptides are formed by amyloid-β precursor protein (AβPP) cleavage, which can be processed by two pathways. The cleavage by the α-secretase A Disintegrin And Metalloprotease 10 (ADAM10) releases the soluble portion (sAβPPα) and prevents senile plaques. This pathway remains largely unknown and ignored, mainly regarding pharmacological approaches that may act via different signaling cascades and thus stimulate non-amyloidogenic cleavage through ADAM10. This review emphasizes the effects of natural compounds on ADAM10 modulation, which eventuates in a neuroprotective mechanism. M…

Bitterness and astringency of flavan-3-ol monomers, dimers and trimers

1999

Intensity of astringency and bitterness of seven flavonoid compounds was evaluated by a time-intensity (TI) procedure. Eighteen trained judges rated intensity continuously from ingestion, through expectoration at 10 s until extinction of the sensation. The seven stimuli included two flavan-3-ol monomers, (+)-catechin and (−)-epicatechin, three dimers and two trimers synthesised from catechin or epicatechin by condensation with (+)-dihydroquercitin. As the degree of polymerisation increased, maximum bitterness intensity (Imax) and total duration (Ttot) decreased whereas astringency Imax increased. The monomers were significantly higher in bitterness at Imax than the dimers, which were signif…

A hypotensive procyanidin-glycoside from Rhamnus lycioides ssp. lycioides.

1990

A lyophilized hot water extract of the aerial parts of Rhamnus lycioides L. (Rhamnaceae) produced a lowering of systemic arterial blood pressure in normotensive anaesthetized Wistar rats. An activity-guided fractionation of the methanolic extract led to the isolation of a tetrameric procyanidin-glycoside which produced a clear dose-dependent hypotensive response (1.5-6 mg/kg i.v.). This principle was characterized using acid hydrolysis, thiolytic degradation and spectroscopic methods. It consisted of four flavanol units with a 2,3-cis configuration and with a O-beta-d-glucosylpyranoside function on the epicatechin terminal unit. The interflavan linkage was (4-8).

Reactions of Flavonoids with o‑Quinones Interfere with the Spectrophotometric Assay of Tyrosinase Activity

2016

Flavonoids are important food components with antioxidant properties and many of them have been described as tyrosinase inhibitors. Oxidation of quercetin, kaempferol, morin, catechin, and naringenin by mushroom tyrosinase and their influence on the oxidation of l-dopa and l-tyrosine was studied. Reaction rates measured spectrophotometrically and by oxygen consumption differed substantially. All tested flavonoids reacted with 4-tert-butyl-o-benzoquinone and/or 4-methyl-o-benzoquinone, although at different rates. These reactions generated products whose UV-vis spectra either overlapped or did not overlap with the spectrum of dopachrome. They therefore strongly influence the kinetic analysis…

Possible Reduction of Cardiac Risk after Supplementation with Epigallocatechin Gallate and Increase of Ketone Bodies in the Blood in Patients with Mu…

2020

Multiple sclerosis (MS) is a neurodegenerative disease that causes anthropometric changes characterised by functional disability, increase in fat mass, and decrease in lean mass. All these variables are related to a greater cardiac risk. The polyphenol epigallocatechin gallate (EGCG) and an increase in ketone bodies in the blood have been shown to have beneficial effects on anthropometric and biochemical variables related to cardiovascular activity. The aim of this study was to analyse the impact of the intervention with EGCG and ketone bodies on cardiac risk in MS patients. A population of 51 MS patients were randomly assigned to a control group and an intervention group (daily dose of 800…

2012

Cancer is a major cause of death worldwide and angiogenesis is critical in cancer progression. Development of new blood vessels and nutrition of tumor cells are heavily dependent on angiogenesis. Thus, angiogenesis inhibition might be a promising approach for anticancer therapy. Anti-angiogenic small molecule and phytochemicals as a cancer treatment approach are focused in these main points; modes of action, adverse effects, mechanisms of resistance and new developments. Treatment with anti-angiogenic compounds might be advantageous over conventional chemotherapy due to the fact that those compounds mainly act on endothelial cells, which are genetically more stable and homogenous compared t…

Hypotensive Effect ofPistacia lentiscusL

1987

AbstractThe present studies were undertaken to confirm the hypotensive effect of Pistacia lentiscus L. in normotensive urethane anaesthetized Wistar rats. It was shown that lyophilized aqueous extract caused a dose-dependent decreased of the systemic arterial blood pressure. Acute toxicity was also determined. Phytochemical analysis revealed the presence of steroids-triterpenes, catechin tannins, flavonoids, sugars, resins and saponins.

A cross-cultural study using Napping (R): Do Korean and French consumers perceive various green tea products differently?

2013

http://www.elsevier.com/locate/foodres ; WOS:000323239400065; International audience; With the increasing demands of global trading, interests in cross-cultural comparisons have increased to gain understanding in the differences of sensory perception and consumer acceptability. The objective of this study was to compare the differences in perception by Korean and French consumers of green tea produced in Korea, China, and Japan, using Napping (R) followed by ultra flash profile. In addition, overall acceptability was examined in both countries. The results of Napping (R) showed that the Korean consumers were able to discriminate the green teas according to their origins and processing metho…

Evaluating ancient Egyptian prescriptions today: Anti-inflammatory activity of Ziziphus spina-christi.

2015

Abstract Background Ziziphus spina-christi (L.) Desf. (Christ's Thorn Jujube) is a wild tree today found in Jordan, Israel, Egypt, and some parts of Africa, which was already in use as a medicinal plant in Ancient Egypt. In ancient Egyptian prescriptions, it was used in remedies against swellings, pain, and heat, and thus should have anti-inflammatory effects. Nowadays, Z. spina-christi, is used in Egypt (by Bedouins, and Nubians), the Arabian Peninsula, Jordan, Iraq, and Morocco against a wide range of illnesses, most of them associated with inflammation. Pharmacological research undertaken to date suggests that it possesses anti-inflammatory, hypoglycemic, hypotensive and anti-microbial e…

Caratteristiche qualitative dei semi delle varietà ad uva da vino Siciliane

2014

In this study, the phenolic compounds of Sicilian grape seeds were evaluated. Flavan-3-ols content was higher in white and relic than black grape seeds. The greater polyphenol quantity found in white cultivars could be also attributed to lower maturity at harvest. The flavan-3-ols content was linked with seed color. The black cultivar showed the highest degree of seed lignification