Effects of flavored mineral waters on AhR–CYP1A1 signaling pathway in primary human hepatocytes and in human hepatic and intestinal cancer cells

Food–drug interaction is an emerging phenomenon, comprising pharmacokinetic or toxicokinetic interactions between food constituents and drugs. The mechanisms include inhibition of enzymes and transporters, and induction of drug metabolizing enzymes. A prominent regulator of drug-metabolizing enzymes is an aryl hydrocarbon receptor (AhR) that transcriptionally regulates CYP1 enzymes, phase II enzymes and many other genes. In the current paper, we have examined the effects of 28 different flavored mineral waters on AhR–CYP1A1 signaling pathway in primary cultures of human hepatocytes and in human cancer cell lines HepG2 (hepatic) and LS174T (intestinal). The techniques of Western blot, RT-PCR and gene reporter assays were employed to determine the expression of CYP1A1 mRNA, protein and activation of AhR, respectively. We have identified four flavored mineral waters which activated AhR and/or induced CYP1A1. These data imply a potential of some flavored mineral waters to cause food–drug interactions. In addition, activation of AhR–CYP1A1 signaling may result in chemically-induced carcinogenesis and alteration of intermediary metabolism.