Search results for "FFEI"
showing 10 items of 171 documents
Vasodilator Effects of Liriodenine and Norushinsunine, Two Aporphine Alkaloids Isolated from <i>Annona cherimolia,</i>in Rat Aorta
1995
The effect of two aporphines, liriodenine and norushinsunine, isolated from Annona cherimolia, were studied in the rat aorta in order to examine their mechanism of action. Both alkaloids (10–7–10–4 mol/l) showed relaxant effects on the contractions elicited by 10–6 mol/l noradrenaline (NA) or 80 mmol/l KC1, but, while liriodenine showed a nonspecific relaxant action on both spasmogens, norushinsunine was more potent on KC1-induced contraction. In Ca2+-free medium, both alkaloids (0.1 mmol/l) inhibited the responses elicited by NA, but not those elicited by caffeine. This inhibitory action occurred when the alkaloids were present during the release of the Ca2+ internal stores or during the r…
Die Wirkung von Theophyllin, Coffein und Theobromin auf Kontraktionskraft, Erregbarkeit, Refrakt�rzeit und Spontanfrequenz des isolierten Herzmuskels…
1956
In the electrically driven papillary muscle of the cat's right ventricle theophylline, caffeine and theobromine exerted a positive inotropic action. Log. dose-effect regression lines for the three drugs were parallel; the effect of theophylline was significantly greater than those of caffeine and theobromine. The range of concentrations used was 1/32–1/2 mM/1.
Adenosine and memory storage
1999
Rationale: Caffeine is a non-selective A1/A2 adenosine receptor antagonist which is known to improve cognitive performance in humans. This effect of caffeine has been attributed to its antagonism of adenosine receptors. Objective: The present study was devised to identify the role of A1 and A2A adenosine receptors in the facilitation of memory consolidation in mice performing a passive avoidance task. Methods: Adult albino Swiss male mice were used. The mice were trained in a step-through inhibitory avoidance task in which they were punished by a foot-shock (0.4 mA, 5 Hz, for 3 s) delivered through the grid floor. Caffeine (0.1, 0.3, 1.0 and 3.0 mg/kg), SCH 58261 (0.1, 0.3, 1.0 and 3.0 mg/k…
DNA-binding and in vitro cytotoxic activity of platinum(II) complexes of curcumin and caffeine
2019
Abstract Three Pt(II) complexes containing the natural ligands curcumin and caffeine, namely [Pt(curc)(PPh3)2]Cl (1), [PtCl(curc)(DMSO)] (2) (curc = deprotonated curcumin) and trans-[Pt(caffeine)Cl2(DMSO)] (3), were synthesized and fully characterized. The data obtained suggest that, for both 1 and 2, the anion of curcumin is coordinated to the platinum ion via the oxygen atoms of the β-diketonate moiety. Spectroscopic features reveal that in 2 and 3, a DMSO molecule is S-bonded to the metal centre. For 3, all data indicate a square-planar geometry formed by a 9-N bonded caffeine, two trans chloride anions and a DMSO. The three complexes undergo changes in solution upon incubation for 24 h;…
Photocatalytic Isomerization of Caffeic Acid and its Cyclization to Esculetin
2015
tThe photoisomerization of trans-caffeic acid to cis-caffeic acid has been studied in the presence of N2in homogeneous aqueous solutions and in suspensions of various TiO2catalysts. The results supportedthe hypothesis of an energy transfer process from TiO2 to the substrate due to the recombination of the photogenerated electron–hole pairs.
Sex differences in estimation of time intervals and in reaction time are removed by moderate but not high doses of caffeine in coffee
2002
Estimation of the passage of time in the seconds-to-minutes range and reaction time are strongly dependent on a hypothetical internal clock. Dopamine is the neurotransmitter most closely related to the rate of this clock. Caffeine, probably the most consumed drug in the world, leads to an augmentation of dopamine neurotransmission. In this study coffee, which reproduces the conditions under which caffeine is normally ingested, containing 3, 75, 150 or 300 mg of caffeine, was given to healthy male and female volunteers. A computerized time estimation and reaction time test was carried out 50 min after ingestion. Sex differences in placebo control subjects (who took decaffeinated coffee with …
Detection of a plant enzyme exhibiting chlorogenate-dependant caffeoyltransferase activity in methanolic extracts of arbuscular mycorrhizal tomato ro…
2012
When Glomus intraradices-colonised tomato roots were extracted in methanol at 6 degrees C, chlorogenic acid (5-caffeoylquinic acid), naturally present in the extract, was slowly converted by transesterification into methyl caffeate. The progress of the reaction could be monitored by HPLC. The reaction only occurred when the ground roots were left in contact with the hydro-alcoholic extract and required the presence of 15-35% water in the mixture. When the roots were extracted in ethanol, chlorogenic acid was transformed to ethyl caffeate in the same conditions. The reaction was also detected in Glomus mosseae-colonised tomato root extracts. It was also detectable in non-mycorrhizal root ext…
Caffeine as a Gelator
2016
Caffeine (a stimulant) and ethanol (a depressant) may have opposite effects in our body, but under in vitro conditions they can “gel” together. Caffeine, being one of the widely used stimulants, continued to surprise the scientific community with its unprecedented biological, medicinal and physicochemical properties. Here, we disclose the supramolecular self-assembly of anhydrous caffeine in a series of alcoholic and aromatic solvents, rendering a highly entangled microcrystalline network facilitating the encapsulation of the solvents as illustrated using direct imaging, microscopy analysis and NMR studies. Peer reviewed
Therapeutic potential of dietary polyphenols against brain ageing and neurodegenerative disorders
2010
In recent years there has been a growing interest, supported by a large number of experimental and epidemiological studies, in the beneficial effects of some commonly used food-derived products in preventing various age-related pathologic conditions, ranging from cancer to neurodegenerative diseases. Spices and herbs often contain active phenolic substances endowed with potent antioxidative and chemopreventive properties. Curcumin is a phytochemical compound extracted from the rhizome of Curcuma Longa. It is the pigment responsible for the characteristic yellow color of Indian curry. Data from our and other laboratories demonstrated that curcumin, as well as some other polyphenols, strongly…
Release and permeation profiles of spray-dried chitosan microparticles containing caffeic acid
2018
Made available in DSpace on 2018-12-11T17:17:17Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-03-01 Caffeic acid (CA), a phenolic compound found in plants with antioxidant and antimicrobial activity, induces collagen production and prevents premature aging of the skin. The objective of this study was to develop two types of chitosan microparticles (MP) containing CA and to relate the morphology with the release and permeation profiles. One type of MP was prepared from a hydroalcoholic solution (MPI) and the other from an aqueous solution (MPII). Their morphology and size was evaluated by high-resolution scanning electron microscopy. The release profile of CA was evaluated using the…