Fig. 1. Increase in NK cytotoxicity through high secretion of granzyme (Grz)-B from NK cell to target cell.

(A) NK cell viability on various concentration of apigenin using CCK-8 assay. (B) cytotoxicity and (C) granzyme B secreted from NK cells cocultured with HCC cells with or without treatment with CoCl₂ (250 μM) and apigenin (50 μM). All data were presented as means ± SD from three independent experiments. *p < 0.05 vs non-treated; **p < 0.05 vs CoCl₂.