Tanshinone IIB, a primary active constituent from Salvia miltiorrhiza, exerts neuroprotective effect via inhibition of neuronal apoptosis in vitro

Tanshinone IIB (TSB) is a major active constituent of the roots of Salvia miltiorrhiza (Danshen) widely used in the treatment of stroke and coronary heart disease in Asian countries. This study investigated the in vitro neuroprotective effects of TSB and the underlying mechanism. Co-treatment with TSB significantly inhibited the cytotoxicity and apoptosis of rat cortical neurons induced by staurosporine in a concentration-dependent manner. Consistently, TSB significantly reduced the DNA laddering caused by staurosporine in a concentration-dependent manner. TSB also suppressed the elevated Bax protein and decreased bcl-2 and caspase-3 proteins induced by staurosporine in rat cortical neurons. These findings indicated that TSB had a neuroprotective effect via inhibition of apoptosis. Further studies are warranted to investigate the role of other apoptosis-related signaling proteins and reperfusion-related mechanisms in the protective effect of TSB on neurons.