Figure 3.

Effect of silymarin on key regulators of cell cycle. Cell cycle progression is controlled by key regulators such as cyclin and their kinase, cyclin-dependent kinase (Cdk). Silymarin and its derivative are able to block tumoral cells in the different phase of the cell cycle through a decrease of cyclins and associated Cdks and to increase the inhibitors proteins that negatively regulate the cell cycle. Furthermore, various antitumoral agents are able to target specific phase of the cell cycle. By this way, silymarin and its derivatives may sensitize cancer cells to these anticancer agents.