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Biotransformation of Xenobiotics in Living Systems—Metabolism of Drugs: Partnership of Liver and Gut Microflora
Published in Peter Grunwald, Pharmaceutical Biocatalysis, 2020
The most common outcome of P450 oxidations is the inactivation of drugs, as is the case with caffeine. Caffeine is a naturally occurring stimulant found in coffee, tea, chocolate and used as an adjuvant analgesic in combination with some nonsteroidal anti-inflammatory drugs (NSAIDs). In humans, more than 80% of administered caffeine (1,3,7-trimethylxanthine) is metabolized by 3-demethylation to inactive metabolite paraxanthine (1,7-dimethylxanthine) via liver CYP1A2 (Fig. 6.3), and approximately 16% is converted to theobromine (3,7-dimethylxanthine) and theophylline (1,3-dimethylxanthine) by 1-demethylation and by 7-demethylation, respectively (Mandel, 2002).
Occurrence of Transformation Products of Pharmaceutical and Personal Care Products in the Aquatic Environment
Published in Leo M. L. Nollet, Dimitra A. Lambropoulou, Chromatographic Analysis of the Environment, 2017
Myrsini Papageorgiou, Eleni Evgenidou, Dimitra A. Lambropoulou
The other stimulant, caffeine, is also extensively metabolized (~80%) through the catalytic action of CYP1A2, forming paraxanthine (PARA-XNT), theobromine, and theophylline (Gu et al., 1992). Ghoshdastidar et al. (2015) have reported high concentrations of PARA-XNT in WWTP effluents in Canada reaching 18.2 ng L−1. PARA-XNT was also determined up to 421.4 ng L−1 in surface water (Baker and Kasprzyk-Hordern, 2011), while Barnes et al. (2008) detected PARA-XNT at 57 ng L−1 in groundwater.
Acute caffeine supplementation and live match-play performance in team-sports: A systematic review (2000–2021)
Published in Journal of Sports Sciences, 2022
Adriano Arguedas-Soley, Isobel Townsend, Aaron Hengist, James Betts
Caffeine (1,3,7-trimethylxanthine) is the most widely consumed central nervous system (CNS) stimulant. The pharmacological effects of caffeine include increased wakefulness, decreased reaction times and an increased ability to perform and sustain cognitive and physical activity (Keisler & Armsey, 2006). Mechanisms of action are believed to target a wide range of organ systems, highlighting the potential for caffeine to enhance various inter-related aspects of human performance, including cognition, strength, speed, endurance and skill. Cognitive effects of caffeine relate to central fatigue resistance and effort perception. The competitive binding of caffeine and paraxanthine to adenosine A1 and A2 receptors in the brain inhibits neuro-modulatory actions of adenosine, which upregulate CNS activity and sympathetic neurotransmitter release (e.g., dopamine; Graham & Spriet, 1995). Caffeine also stimulates the secretion of beta-endorphins which, due to their analgesic properties, may reduce the perception of pain (Laurent et al., 2000).
Neuromotor activity inhibition in zebrafish early-life stages after exposure to environmental relevant concentrations of caffeine
Published in Journal of Environmental Science and Health, Part A, 2021
Natália Oliveira de Farias, Thayres de Sousa Andrade, Viviani Lara Santos, Pedro Galvino, Paula Suares-Rocha, Inês Domingues, Cesar Koppe Grisolia, Rhaul Oliveira
Continuous input of CAF in the natural environments is expected due to the discharges of domestic effluents. This compound is readily metabolized and its metabolites (paraxanthine, theophylline, theobromine) may be present in natural ecosystems. Several authors have already reported detectable concentrations of CAF (13 ng/L to 20 µg/L as maximum concentrations) in the aquatic environment, as rivers and surface waters worldwide.[68–71] Since CAF does not occur alone in the environment, its combination with other compounds discharged in the water bodies should be considered, since synergistic or antagonistic effects may be related to these interactions. Disruption of the developmental process by environmental toxins, pharmaceutical drugs, or a mixture of other chemical compounds may have negative long-term consequences. Thus, extensive monitoring of their concentrations in water bodies linked with better control of domestic effluent emissions, including those related to CAF, is essential for the protection of aquatic ecosystems.
Effects of acute ingestion of caffeine on team sports performance: a systematic review and meta-analysis
Published in Research in Sports Medicine, 2019
Juan José Salinero, Beatriz Lara, Juan Del Coso
Perhaps, the most tested research hypothesis to explain the existence of “non-responders to caffeine” is the occurrence of one or various genetic polymorphism that preclude(s) in part the physiological effects derived from acute caffeine ingestion. Specifically, the polymorphisms in the CYP1A2 (-163C>A; rs762551) and ADORA2A genes (1976C>T; rs5751876) have been postulated as modifiers of the ergogenic response to caffeine ingestion. Several investigations, using endurance-like tests to assess performance, have found that AA homozygotes of the CYP1A2 gene obtained inferior ergogenic benefits from acute caffeine intake than C-allele carriers (Guest, Corey, Vescovi, & El-Sohemy, 2018; Rahimi, 2018; Womack et al., 2012), likely due to a faster capacity to metabolize caffeine into paraxanthine (Djordjevic, Ghotbi, Jankovic, & Aklillu, 2010). However, other investigations have found that AA homozygotes have a similar (Pataky et al., 2016) or even a higher ergogenic response to caffeine than C-allele carriers (Algrain et al., 2016; Salinero et al., 2017). A recent investigation carried out with basketball players found that both AA homozygotes and C-allele carriers similarly increased their physical performance in basketball during specific testing and a simulated match after the administration of an acute dose of caffeine (Puente, Abian-Vicen, Del Coso, Lara, & Salinero, 2018). Regarding the ADORA2A gene, it has been found that C-carriers showed a decreased ergogenic response to caffeine in comparison to TT homozygotes (Loy, O’Connor, Lindheimer, & Covert, 2015). While it seems clear that genetics affects the magnitude of the ergogenic effects derived from caffeine supplementation, and contributes to the interindividual differences in response to acute caffeine ingestion, future research should determine which genes unequivocally affect the ergogenicity of caffeine, as well as the mechanisms behind this effect (Southward, Rutherfurd-Markwick, Badenhorst, & Ali, 2018).