Multiple pro-apoptotic targets of abietane diterpenoids from Salvia species

The genus Salvia contains a large number of biologically active diterpenoids with various skeletons including abietanes, labdanes, clerodanes, pimaranes and icetexanes. Diterpenes of Salvia species showed various biological activities, particularly cytotoxic and anti-proliferative properties. In recent years many studies have been focused on the molecular mechanisms of these diterpenes in cancer cells. It should be noted, however, that anticancer studies on diterpenoids from Salvia species were dominated by tanshinones (a class of abietanes) over the past decades. A large number of targets of diterpenes have been identified in cancer cells including NF-κB, STAT3, Bcl-xL, β-catenin, cytochrome C and caspases. These studies give us deeper insights into the mechanisms of actions and cell signaling pathways of anticancer diterpenoids from Salvia species. This paper reviews protein targets of diterpenoids from Salvia species and highlights the gaps in our knowledge deserving future research.