Figure 4.

Boxplots showing the extracellular lactate dehydrogenase (LDH) activity of hepatocyte—non-parenchymal cells in 2D (Study 1: (A) and Study 2: (B)) and 3D (Study 1: (C) and Study 2: (D)) co-cultures as indicated by enzyme kinetic assay (n_{study 1} = 6/group, n_{study 2} = 5/group). Relative changes in absorbances were calculated by considering the mean value of control cultures as 1. The “CTR” refers to control cells that received none of the treatments. The treatments were: LPS10 and LPS50 = 10 and 50 µg/mL lipopolysaccharide (LPS) from Escherichia coli, LTA10 and LTA50 = 10 and 50 µg/mL lipoteichoic acid (LTA) from Staphylococcus aureus, ETxB-1 and -2 = 20 and 50 µg/mL subunit B of heat-labile enterotoxin of Escherichia coli, Flag-1 and -2 = 100 and 250 ng/mL flagellin from Salmonella Typhimurium, PMA-1 and -2 = 100 and 1000 ng/mL phorbol myristate acetate (PMA), poly-IC-1 and -2= 50 and 100 µg/mL polyinosinic polycytidylic acid (poly I:C). Asterisks over the boxes refer to significant differences compared to “CTR” cells within the same cell culture model and the same study. * p < 0.05, ** p < 0.01.