Chelating properties of beer: Implications on calcium homeostasis in PE/CA-PJ15 cells

Abstract

Beer contains a large variety of different molecules, of which some can chelate Ca2+. Here, we show that in PE/CA-PJ15 cells, an experimental model previously employed to investigate Ca2+ homeostasis, chemical entities with Ca2+-chelating properties can markedly impact intra- and extra-cellular levels of the metal ion. This was consistently shown by commercial beers, as well as aliquots of unfinished product taken during the last step (clarification) of the brewing process. Our data suggest that a large number of molecules with chelating properties, can cross the cell membrane and, thus, potentially lead to important biological effects associated with changes in Ca2+ homeostasis. In this regard, when PE/CA-PJ15 cells were exposed to H2O2 in order to experimentally prompt an oxidative stress, beer antagonized a non-capacitative Ca2+ entry that was otherwise elicited by H2O2 in its absence. Higher Ca2+-chelating activity of stout, as compared to lager beer, suggest that melanoidins, which are generally present in dark malts, are major chelating agents in dark beers. Further, based on dose-response determinations, we report, for the first time, that Ferulic Acid can bind both intra- and extra-cellular Ca2+ and, as one of the most abundant hydroxycinnamic acids in malted barley, largely account for Ca2+ chelation.These results support the notion that beer may be considered a natural source of chemical entities that, based on their binding activity to Ca2+ and, possibly, other metal ions, might be considered as nutritional supplements, detoxification agents, or antibiotics.