Herb-drug interactions with Danshen (Salvia miltiorrhiza): a review on the role of cytochrome P450 enzymes.

Danshen, the dried root and rhizome of Salvia miltiorrhiza Bunge, is a widely used medicinal plant for the treatment of cardiovascular diseases in China and a complementary medicine in the West. Danshen is indexed in the 2010 Chinese Pharmacopoeia, with more than 35 formulations and concoctions containing Danshen water-extracts, ethanolic extracts or their combination, which are rich in phenolic acids and different levels of tanshinones. There are rare reports on the adverse effects of Danshen preparations. It is, however, well-known that Danshen leads the anticoagulation failure of warfarin. The Danshen-warfarin interaction may be mediated via both pharmacodynamic and pharmacokinetic mechanisms. This review does not summarize recent progress, but the effects of Danshen and its active ingredients on the interactions of cytochrome P450 (CYP450) and drug transporters, as well as the analysis of ingredients, and the metabolism and pharmacokinetics that are related to these interactions. Tanshinones play significant roles in the inhibition and induction of several CYP450 isozymes. It can be concluded that precautions should be taken when using Danshen preparations rich in tanshinones for CYP-related herb-drug interactions.