title: Cytochrome P450-dependent metabolism of caffeine in Drosophila melanogaster.
abstract: Caffeine (1, 3, 7-trimethylxanthine), an alkaloid produced by plants, has antioxidant and insecticide properties that can affect metabolism and cognition. In vertebrates, the metabolites derived from caffeine have been identified, and their functions have been characterized. However, the metabolites of caffeine in insects remain unknown. Thus, using radiolabelled caffeine, we have identified some of the primary caffeine metabolites produced in the body of Drosophila melanogaster males, including theobromine, paraxanthine and theophylline. In contrast to mammals, theobromine was the predominant metabolite (paraxanthine in humans; theophylline in monkeys; 1, 3, 7-trimethyluric acid in rodents). A transcriptomic screen of Drosophila flies exposed to caffeine revealed the coordinated variation of a large set of genes that encode xenobiotic-metabolizing proteins, including several cytochromes P450s (CYPs) that were highly overexpressed. Flies treated with metyrapone--an inhibitor of CYP enzymes--showed dramatically decreased caffeine metabolism, indicating that CYPs are involved in this process. Using interference RNA genetic silencing, we measured the metabolic and transcriptomic effect of three candidate CYPs. Silencing of CYP6d5 completely abolished theobromine synthesis, whereas CYP6a8 and CYP12d1 silencing induced different consequences on metabolism and gene expression. Therefore, we characterized several metabolic products and some enzymes potentially involved in the degradation of caffeine. In conclusion, this pioneer approach to caffeine metabolism in insects opens novel perspectives for the investigation of the physiological effects of caffeine metabolites. It also indicates that caffeine could be used as a biomarker to evaluate CYP phenotypes in Drosophila and other insects.
authors: CNRS 6265, INRA 1324, Université de Bourgogne, Centre des Sciences du Goût et de l'Alimentation, F-21000, Dijon, France.
authors: Alexandra
authors: A
authors: Coelho
authors: CNRS 6265, INRA 1324, Université de Bourgogne, Centre des Sciences du Goût et de l'Alimentation, F-21000, Dijon, France.
authors: Stephane
authors: S
authors: Fraichard
authors: INRA, CNRS, UNSA, UMR 1355, Institut Sophia Agrobiotech, F-06903, Sophia Antipolis, France.
authors: Gaëlle
authors: G
authors: Le Goff
authors: CNRS 6265, INRA 1324, Université de Bourgogne, Centre des Sciences du Goût et de l'Alimentation, F-21000, Dijon, France.
authors: Philippe
authors: P
authors: Faure
authors: CNRS 6265, INRA 1324, Université de Bourgogne, Centre des Sciences du Goût et de l'Alimentation, F-21000, Dijon, France.
authors: Yves
authors: Y
authors: Artur
authors: CNRS 6265, INRA 1324, Université de Bourgogne, Centre des Sciences du Goût et de l'Alimentation, F-21000, Dijon, France.
authors: Jean-François
authors: JF
authors: Ferveur
authors: CNRS 6265, INRA 1324, Université de Bourgogne, Centre des Sciences du Goût et de l'Alimentation, F-21000, Dijon, France.
authors: Jean-Marie
authors: JM
authors: Heydel
mesh_terms: D000818:Animals; D002110:Caffeine / Q000378:metabolism* / Q000494:pharmacology; D003577:Cytochrome P-450 Enzyme System / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D020868:Gene Silencing; D008297:Male; D015262:Xenobiotics / Q000378:metabolism / Q000494:pharmacology
chemical_list: D015262:Xenobiotics; D002110:Caffeine; D003577:Cytochrome P-450 Enzyme System