Recent insights into the biological activities and drug delivery systems of tanshinones

Tanshinones, the major lipid-soluble pharmacological constituents of the Chinese medicinal herb Tanshen (Salvia miltiorrhiza), have attracted growing scientific attention because of the prospective biomedical applications of these compounds. Numerous pharmacological activities, including anti-inflammatory, anticancer, and cardio-cerebrovascular protection activities, are exhibited by the three primary bioactive constituents among the tanshinones, ie, tanshinone I (TNI), tanshinone IIA (TNIIA), and cryptotanshinone (CPT). However, due to their poor solubility and low dissolution rate, the clinical applications of TNI, TNIIA, and CPT are limited. To solve these problems, many studies have focused on loading tanshinones into liposomes, nanoparticles, microemulsions, cyclodextrin inclusions, solid dispersions, and so on. In this review, we aim to offer an updated summary of the biological activities and drug delivery systems of tanshinones to provide a reference for these constituents in clinical applications.