Pharmacokinetic Drug Interaction Between Rosuvastatin and Tanjin in Healthy Volunteers and Rats.

BACKGROUND: Tanjin is an herbal medicine made from the root of salvia miltiorrhiza. It is predominantly given to arteriosclerotic patients as a supplement to ameliorate the clinical symptoms of cardiovascular diseases. In China, tanjin is used frequently in combination treatment for hypercholesterolemia. Thus, there is a high probability of combination of tanjin and statins in these arteriosclerotic patients. This study investigated the interaction between tanjin and rosuvastatin. METHODS: We performed a randomized single-blind, two-period crossover clinical trial on six healthy male volunteers. Volunteers were administered rosuvastatin with placebo or a tanjin-containing drug randomly. The blood samples were collected before drug administration, and at 0.5, 1, 1.5, 2, 4, 8, and 12 hours after administration. Lymphocytes were isolated from blood samples before and 12 hours after drug administration to measure mRNA. As an animal experiment, an in situ intestinal injection with portal vein sampling model was used to examine the interaction between tanjin and rosuvastatin during the absorption phase. Rosuvastatin or rosuvastatin combined with tanjin solution was injected into the intestine. After injection, blood from the portal vein was collected and the concentration of rosuvastatin was measured by LC/MS/MS analysis. A portion of the intestine and liver from the rats was collected and stored at -80°C for mRNA measurement. RESULTS: In the clinical trial, co-administration of tanjin decreased the maximum plasma concentration (Cmax) of rosuvastatin by 26.85% compared with rosuvastatin alone, and also decreased the area under the plasma concentration-time curve of rosuvastatin from 0 to 12 h (AUC0-12) by 19.43%. The relative expression of BCRP and OATP mRNA in human lymphocytes was increased by co-administration of tanjin. In the animal experiment, co-administration of tanjin extract reduced the concentration of rosuvastatin to 84.4, 64.4, and 50.0% at 15, 30, and 45 minutes, respectively. The tanjin-containing drug had a similar effect to tanjin extract. Furthermore, tanjin significantly reduced the absorption of rosuvastatin and the inhibitory effects lasted for at least 24 hours. Tanjin increased the relative expression of BCRP mRNA in the intestine, but it did not change the expression of OATP. Moreover, the concentration of rosuvastatin in the portal vein and systemic blood was reduced. In the liver, tanjin increased both BCRP and OATP mRNA expression, which was consistent with the results from human lymphocytes. CONCLUSION: The clinical trial and animal experiment revealed that tanjin can significantly reduce the absorption of rosuvastatin. This interaction occurred, at least, at the absorption phase in the small intestine due to the enhanced efflux transport. Thus, as tanjin and rosuvastatin were found to interact, their combination needs to be paid attention to.