Pharmacological Actions of Tanshinone IIA with Special Focus on Nrf-2 Signaling Pathway

Salvia miltiorrhiza Bunge, Lamiaceae, widely recognized as “danshen,” Chinese sage, is an important long-established traditional Chinese medication, and tanshinone IIA is a lipophilic component of the root extracts of this perennial plant. Modern research shows that tanshinone IIA possesses a remarkable range of pharmacological properties like antioxidant, cardio-protective, and immunomodulatory properties. It serves a protective function in different disorders ranging from cardiovascular disorders to neurodegenerative disorders. It has also been established that tanshinone IIA can block the progression of carcinoma by destroying tumor cells, encouraging cell differentiation, and triggering apoptosis. Importantly, the anti-inflammatory, anti-thrombotic, and neuroprotective functions of tanshinone IIA are due to its ability to modulate signaling pathways such as TLR/NF-κB and MAPKs/NF-κB pathway. Interestingly, nuclear factor erythroid 2–related factor 2 (Nrf2) controls the expression levels of several genes with cytoprotective effects. In addition, Nrf2 protective function has been observed in preclinical studies of liver diseases, ischemia stroke, cancer, neurodegenerative diseases, and various other brain disorders as Nrf2 activation has been found to inhibit oxidative stress and inflammation. Therefore, Nrf2 can be regarded as a possible therapeutic target for a variety of disorders. The present review aims to provide a summary of diverse in vitro and in vivo research that explored the pharmacological activities of tanshinone IIA via the Nrf-2 pathway to deliver a better understanding of its potential in different disorders. Graphical Abstract