FIGURE 1.

In vitro UGT1A regulation by coffee and different coffee ingredients. A UGT1A3 reporter gene construct was tested for inducibility by green coffee (a), coffee aromatics, trigonelline (b), and coffee acids (c) in KYSE70 cells. Different UGT1A reporter gene constructs were induced by coffee and a combination of caffeic acid (CA) and caffeic acid phenylethyl ester (CAPE) in KYSE70 cells (d) and HepG2 cells (e). Columns represent mean ± SD from five independent experiments analysing one treatment group consisting of three individual cell culture wells (in total 15 wells). Significance was determined in relation to basic control vector. *P < 0.05; n.s., non‐significant