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Theobromine

About: Theobromine is a research topic. Over the lifetime, 1137 publications have been published within this topic receiving 29723 citations. The topic is also known as: 3,7-Dimethylxanthine & Theobromin.


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Journal ArticleDOI
TL;DR: The results confirm that CYP1A2 is the main enzyme catalysing the biotransformation of caffeine, in particular the N3-dem methylation and partly the N1- and N7-demethylation and the results indicate that intake of caffeine during fluvoxamine treatment may lead to caffeine intoxication.
Abstract: The selective serotonin reuptake inhibitor fluvoxamine is a very potent inhibitor of the liver enzyme CYP1A2, which is the major P450 catalysing the biotransformation of caffeine. Thus, a pharmacokinetic study was undertaken with the purpose of documenting a drug-drug interaction between fluvoxamine and caffeine. The study was carried out as a randomized, in vivo, cross-over study including eight healthy volunteers. In Period A of the study, each subject took 200 mg caffeine orally, and in Period B, the subjects took fluvoxamine 50 mg per day for 4 days and 100 mg per day for 8 days. On day 8 in Period B, the subjects again ingested 200 mg caffeine. After caffeine intake, blood and urine were sampled at regular intervals. Caffeine and its three primary demethylated metabolites, paraxanthine, theobromine and theophylline in plasma and the same four compounds plus 11 more metabolites in urine were assayed by HPLC. During fluvoxamine, the median of the total clearance of caffeine decreased from 107 ml min-1 to 21 ml min-1 and the half-life increased from 5 to 31 h. The N3-demethylation clearance of caffeine to paraxanthine decreased from 46 to 9 ml min-1; the N1- and N7-demethylation clearances decreased from 21 to 9 ml min-1 and from 14 to 6 ml min-1, respectively. The results confirm that CYP1A2 is the main enzyme catalysing the biotransformation of caffeine, in particular the N3-demethylation and partly the N1- and N7-demethylation. The results indicate that intake of caffeine during fluvoxamine treatment may lead to caffeine intoxication. Finally, our study provides additional evidence that fluvoxamine can be used to probe CYP1A2 in drug metabolism.

104 citations

Journal ArticleDOI
TL;DR: It was tentatively concluded that caffeine may have more CNS-mediated effects on alertness, while theobromine may be acting primarily via peripheral physiological changes on mood and blood pressure.

104 citations

Journal ArticleDOI
TL;DR: The lack of significant cocoa and interaction effects suggested that theobromine may be the main ingredient responsible for the HDL cholesterol-raising effect.

99 citations

Journal ArticleDOI
TL;DR: Results show that long-term treatment with caffeine in a dose that gives plasma levels of 6-10 microM decreases the effects of NMDA on e.g. seizure susceptibility, and that this effect cannot be ascribed to changes of A1 adenosine receptor density.

97 citations

Journal ArticleDOI
TL;DR: Like the dopamine agonist apomorphine, the methylxanthines caffeine, theophylline and theobromine produced dose-dependent contralateral rotation in rats with unilateral 6-hydroxydopamine denervation, a response considered to be dependent upon dopamine receptors rendered supersensitive.
Abstract: Like the dopamine agonist apomorphine, the methylxanthines caffeine, theophylline and theobromine produced dose-dependent contralateral rotation in rats with unilateral 6-hydroxydopamine denervation, a response considered to be dependent upon dopamine receptors rendered supersensitive. This response was also observed after the injection of the substances into the denervated striatum. Indeed, intrastriatal administration of caffeine into the dopamine denervated striatum produced, dose-dependently (1.0–50.0 μg/μl), contralateral rotation. However, while apomorphine produced ipsilateral rotation in rats with unilateral striatal kainic acid lesions, a response considered to be dependent upon normosensitive dopamine receptors, neither caffeine nor theophylline produced rotational responses. As for apomorphine, the rotational behaviour elicited by caffeine (15.0 mg/kg SC) and theophylline (25.0 mg/kg SC) was inhibited by the dopamine antagonistscis-(Z)flupentixol, haloperidol and sulpiride. Nevertheless, despite the fact thatcis-(Z)flupentixol was the most potent inhibitor of the caffeine response, no more than 50% inhibition was produced with doses as high as 1.0–10.0 mg/kg SC ofcis-(Z)flupentixol. Pretreatment with alpha methyl-p-tyrosine inhibited the rotational response produced by caffeine in 6-OHDA-lesioned animals, but did not significantly modify the apomorphine response. Furthermore, the benzodiazepine diazepam produced a dose-dependent inhibition of the caffeine rotation, but again, the apomorphine response, although qualitatively modified, was not significantly inhibited.

97 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202339
202288
202122
202036
201937
201840