Table . Cytotoxic activity of madecassic acid (2), silybin and their conjugated madecassic acidsilybin derivatives on HepG2 cancer cell lines. a Alcohol on the silybin unit through which conjugation is achieved. b +Ac = acetylation, -H2O = dehydration on 2,3 positions on silybin (S) or 5,6 positions on madecassic acid (M). Ellipticine was used as a positive control and all values were generated using in a 96 hour MTT assay (n ≥ 3 assay repeats).