A study about drug combination therapy of Schisandra sphenanthera extract and Rapamycin in healthy subjects

To assess the effect of the drug combination of Schisandra sphenanthera extract (SchE) and Rapamycin (RAPA), 18 healthy subjects were given oral treatments of RAPA alone and with SchE. Pharmacokinetic investigations and indexes of hepatic and renal functions, as well as other indices of oral RAPA administration (2 mg), were performed both before and after the SchE treatment period. Whole-blood RAPA concentrations were determined by enzyme-linked immunosorbent assay. The research found that the mean whole-blood RAPA AUC(0-infinity), C-max, and t(max) increased almost 2-, 2.1-, and 1.3-fold, respectively, and CL/F (-38.0%) decreased almost 1.6-fold in these subjects when RAPA was administered with SchE compared with oral RAPA administered alone. The results of this study proved that SchE can increase the oral bioavailability of RAPA and will add important information to the interaction area between drugs and herbal products.