Identification of Beer Bitter Acids Regulating Mechanisms of Gastric Acid Secretion

• Published in: Journal of agricultural and food chemistry Vol. 60; no. 6; pp. 1405 - 1412
• Main Authors: Walker, Jessica, Hell, Johannes, Liszt, Kathrin I, Dresel, Michael, Pignitter, Marc, Hofmann, Thomas, Somoza, Veronika
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 15.02.2012
• Subjects: acetylcholine; Beer - analysis; Beers; Biological and medical sciences; bitter acids; bitterness; Carboxylic Acids - analysis; Carboxylic Acids - pharmacology; Cell Line, Tumor; Chromatography, High Pressure Liquid; citric acid; dyes; ethanol; Ethanol - pharmacology; fermentation; Fermented food industries; Food industries; Fundamental and applied biological sciences. Psychology; gastric acid; Gastric Acid - secretion; gene expression; Gene Expression - drug effects; genes; glucose; histamine; Humans; Hydrogen-Ion Concentration; iso-alpha acids; malic acid; quantitative polymerase chain reaction; Receptor, Muscarinic M1; Receptor, Muscarinic M3 - genetics; Receptors, Muscarinic; secretion; somatostatin; Stomach Neoplasms; succinic acid; Tandem Mass Spectrometry; gastric acid secretion; hop-derived bitter acids; HGT-1 cells; beer; organic acids; Alcoholic beverage; Secretion; Hop; Identification; Cell; Organic acids; Mechanism; Beer
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf204306z

Beer, one of the most consumed beverages worldwide, has been shown to stimulate gastric acid secretion. Although organic acids, formed by fermentation of glucose, are known to be stimulants of gastric acid secretion, very little is known about the effects of different types of beer or the active constituents thereof. In the present study, we compared the effects of different beers on mechanisms of gastric acid secretion. To investigate compound-specific effects on mechanisms of gastric acid secretion, organic acids and bitter compounds were quantified by HPLC-DAD and UPLC-MS/MS and tested in human gastric cancer cells (HGT-1) by means of a pH-sensitive fluorescent dye which determines the intracellular pH as an indicator of proton secretion. The expression of relevant genes, coding the H+/K+-ATPase, ATP4A, the histamine receptor, HRH2, the acetylcholine receptor, CHRM3, and the somatostatin receptor, SSTR2, was determined by qPCR. Ethanol and the organic acids succinic acid, malic acid, and citric acid were demonstrated to contribute to some extent to the effect of beer. The bitter acids comprising α-, β-, and iso-α-acids were identified as potential key components promoting gastric acid secretion and up-regulation of CHRM3 gene expression by a maximum factor of 2.01 compared to that of untreated control cells with a correlation to their respective bitterness.