title: Time-dependent component-specific regulation of gastric acid secretion-related proteins by roasted coffee constituents.
abstract: Consumption of coffee beverages has been reported to cause gastric irritation in some consumers as a result of increased gastric acid secretion. In the complex mechanisms of gastric acid secretion, the activity and expression of the H+,K+-ATPase is regulated by transmitters, such as histamine, acetylcholine, gastrin, somatostatin, and their corresponding receptors. Here, we report the effect of three coffee constituents, chlorogenic acid, caffeine, and N-methyl pyridinium ions, on the expression of the histamine receptor H2, the acetylcholine receptor M3, the gastrin receptor, the somatostatin receptor, and the H+,K+-ATPase. Human gastric cancer cells were exposed to chlorogenic acid, caffeine, or N-methyl pyridinium in their coffee brew-representative concentrations as well as to physiological stimulators of gastric acid secretion. Gene expression levels of receptor proteins and those of the H+,K+-ATPase were measured at different time points by real-time PCR. Expression of prosecretory receptors significantly increased between one and one-half to twofold after treatment with chlorogenic acid or caffeine compared to control cells at the same time point. Chlorogenic acid and caffeine also increased the H+,K+-ATPase gene expression twofold higher compared to control cells. In contrast, N-methyl pyridinium downregulated the expression of the prosecretory gastrin receptor significantly, by -27%. In conclusion, chlorogenic acid, caffeine, and N-methyl pyridinium impair the expression of gastric acid secretion-related proteins in a time-dependent manner. Future work will be aimed at the elucidation of the cooperative interplay of individual components using recombinates of single coffee constituents.
authors.affiliation: Deutsche Forschungsanstalt für Lebensmittelchemie, Garching, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Rubach
authors.forename: R
authors.initials: R
authors.lastname: Lang
authors.forename: T
authors.initials: T
authors.lastname: Hofmann
authors.forename: V
authors.initials: V
authors.lastname: Somoza
mesh_terms: D001628:Beverages; D002478:Cells, Cultured; D002726:Chlorogenic Acid / Q000494:pharmacology; D003069:Coffee; D003296:Cooking; D005750:Gastric Juice / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D005755:Gastrins / Q000494:pharmacology; D017506:H(+)-K(+)-Exchanging ATPase / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D013004:Somatostatin / Q000494:pharmacology
chemical_list: D003069:Coffee; D005755:Gastrins; D002726:Chlorogenic Acid; D013004:Somatostatin; D017506:H(+)-K(+)-Exchanging ATPase