Coompo Research Chemicals

Tanshinone IIB (TSB) is a major active constituent of the roots of Salvia miltiorrhiza. 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.

TSB at 5 and 25 mg/kg by intraperitoneal injection significantly reduced the focal infarct volume, cerebral histological damage and apoptosis in rats subjected to middle cerebral artery occlusion (MCAO) compared to MCAO rats receiving vehicle. This study demonstrated that TSB was effective in reducing stroke-induced brain damage and may represent a novel drug candidate for further development. Further mechanistic studies are needed for the neuron-protective activity of TSB.
TSB significantly inhibited the uptake of digoxin and vinblastine in membrane vesicles containing PgP or MRP1. TSB also moderately stimulated PgP ATPase activity. Taken collectively, our findings indicate that TSB is a substrate for PgP and MRP1 and that drug resistance to TSB therapy and drug interactions may occur through PgP and MRP1 modulation.