Tanshinone IIA (TSA) is a major lipophilic component of extracts from the root of S. miltiorrhiza, used widely in Chinese herbal medicine. It has anti-inflammatory activity, inhibiting production of TNF-α, IL-1β, IL-6, NO, INFγ, and expression of iNOS, and IL-12. It blocks human aortic smooth muscle cell migration, inhibits MMP-9 activity, and interferes with PI3K/Akt and ERK1/2 signaling pathways. It is cytotoxic to various cancer cells including A549 lung cancer cells and leukemia cells.Reduction of TSA by NAD(P)H:quinone oxidoreductase (NQO1) generates an unstable intermediate resulting in reactive oxygenase species-mediated apoptotic cell death.
