Pharmacokinetic investigation on nteraction between hydrophilic lithospermic acid B and lipophilic tanshinone IIA in rats: an experimental study

ObjectiveTo elucidate the interaction between hydrophilic lithospermic acid B and lipophilic tanshinone II A in rats.MethodsA reliable high-performance liquid chromatography method was adopted for simultaneous determination of lithospermic acid B and tanshinone II A in rat plasma, through which the pharmacokinetic interaction between lithospermic acid B and tanshinone II A by intravenous injection was investigated.ResultsThe simultaneous intravenous injection of tanshinone II A and lithospermic acid B significantly altered the pharmacokinetic parameters of both compounds when compared with the individual intravenous administration of each compound. The area under the concentration-time curve of tanshinone II A and lithospermic acid B increased by 18.35 and 59.31%, respectively. The mean retention time of tanshinone II A and lithospermic acid B increased, respectively, from 9.3 to 32.8 h and 20.2 to 49.1 h. The concomitant use of tanshinone II A magnified the volume of distribution at steady state (Vss) and time for the drug in the plasma to reduce the highest concentration by half (t1/2) of lithospermic acid B, while at the same time the Vss and t1/2 of tanshinone II A changed significantly in the presence of lithospermic acid B.ConclusionLithospermic acid B and tanshinone II A interact with each other following simultaneous intravenous injection in rats and this observation may expand the clinical use of Danshen (Radix Salviae Miltiorrhizae).