Pharmacokinetic interaction between tanshinones and polyphenolic extracts of Salvia miltinorrhiza Bunge after intravenous administration in rats

Abstract

The objective of this study was to investigate the interaction between tanshinones and polyphenolic extracts of Salvia miltiorrhiza BUNGE in rats. The rats in the medium dose groups were given an intravenous administration of 10 mg/kg tanshinones extract-loaded emulsion (equivalent to 4.0 mg/kg tanshinone IIA (TSIIA)), 100 mg/kg polyphenolic extract solution (equivalent to 61.2 mg/kg salvianolic acid B (Sal B)) or mixed extracts-loaded emulsion (equivalent to 4.0 mg/kg TSIIA and 61.2 mg/kg Sal B). The dosage given to the low dose groups was half that of the medium dose groups, while the high dose groups received twice the dosage of the medium dose groups. The areas under the plasma concentration-time curve (AUC) of TSIIA and Sal B were considerably increased (about 2-14 fold) after intravenous administration of mixed extracts-loaded emulsion in comparison with the equivalent dose of the corresponding extract administration. An increase of about 2-fold was observed in both the low and medium dose groups for TSIIA and Sal B, while there was at least a 14- and 5-fold significant increase (p<0.01) for TSIIA and Sal B in the high dose groups, respectively which was due to a significant (p<0.01) reduction in total plasma clearance (CLt). The peak plasma concentrations (C 0.083 h) of TSIIA and Sal B were also both significantly increased (p<0.01). However, no significant differences in the terminal elimination half-life (t1/2) of TSIIA and Sal B in the mixed extracts-loaded emulsion groups were found compared with that of the corresponding extract groups except for the high dose groups of TSIIA (p<0.05). Therefore, a pharmacokinetic interaction occurs between tanshinones and polyphenolic extracts of Salvia miltinorrhiza BUNGE after intravenous administration in rats, which affects the pharmacokinetic process of TSIIA and Sal B in vivo. © 2008 Pharmaceutical Society of Japan.