Figure 7. Effect of silibinin on mitogen-induced cell signaling pathways. Effect of silibinin on (A) receptor tyrosine kinase (RTK’s) regulated activation of AKT and MAPK1/3 levels; (B) constitutively activated levels of AKT and MAPK1/3, under serum (left panel) and serum starved (middle panel) conditions, and kinase activity of MAPK1/3 and AKT (right panel). (C) Time-dependent effect of silibinin and antioxidants on MAPK1/3 activation under serum conditions. (D) Effect of MAP2K1/2 inhibitor (PD98059) and antioxidant NAC on silibinin-caused or EGF induced activation of MAPK1/3 levels under serum-starved conditions. All experimental procedures and data analysis were performed as detailed in Materials and Methods.