Concentration and time effects of degraded and undegraded carrageenan in Caco-2 cell line, as measured by the MTT assay. Caco-2 cells were treated with (A) FGKC, (B) DKC (C) CGKC (D) FGIC and (E) CGIC at concentrations of 62.5 – 2000.0 μg mL−1 and (F) tamoxifen at concentrations of 0.625- 20.000 μg mL−1 for 24 – 72 h. The percentages of cell viability were calculated by comparing the absorbance of treated and untreated cells. Degraded FGKC, DKC and CGKC showed IC50 in Caco-2 cells (black bold line) while IC50 values were not found in undegraded carrageenan treated cells (black dotted line). Each experiment had 3 replicates from 3 independent experiments (n = 3). The results are expressed as the mean ± SE. α: significant difference at 24 h; β: significant difference at 48 h and *: significant difference at 72 h for degraded carrageenan. Significant differences of undegraded carrageenan were in red symbols.