Pharmacokinetic synergy from the XXXX extract of Taxus chinensis improves the bioavailability of @entity1311 .

@entity43 @entity137 @entity0 @entity5 @entity1311 @entity4045 @entity3907 @entity98 @entity35
BACKGROUND: Taxus chinensis (Pilger) Rehd is widely distributed in China and the northern hemisphere, and the most popular medicinal component isolated from Taxus chinensis is @entity1311 ( @entity4045 ), which has now become the first-line chemotherapeutic drug for @entity0 and @entity43 . Oral administration of pure @entity4045 as a potential anti- @entity5 agent is compromised by low bioavailability. HYPOTHESIS/PURPOSE: In the clinical practice of traditional Chinese medicine, drug co-administration in the form of mixtures or formula could achieve pharmacokinetic/pharmacodynamic synergies. In this study, we aimed to investigate whether there exist any 'inherent' phytochemical synergy from Taxus chinensis extract that could improve @entity4045 bioavailability. STUDY DESIGN: Pharmacokinetic study of @entity4045 after oral administration of Taxus chinensis extracts or single @entity4045 was performed. In addition, comparative cytotoxic studies were carried out on the MCF-7 @entity0 cell lines. METHODS: The plasma concentrations of @entity4045 were determined using a validated high performance chromatography tandem mass spectrometry method. The @entity137 was compared using the @entity98 assay. RESULTS: Oral administration of @entity3907 fractions isolated from Taxus chinensis (containing 17.2% @entity4045 ) could achieve remarkably higher blood concentration and systemic exposure of @entity4045 in @entity35 , while the retention of @entity4045 was significantly improved. Further tissue distribution analysis revealed that the penetration of @entity4045 into major tissues was drastically increased compared with that of single @entity4045 . In addition, in MCF-7 cells, the co-existing components in @entity3907 mixtures could strengthen the inhibitory effects of @entity4045 on @entity5 cell proliferation. CONCLUSION: Together, these results support that administration of @entity4045 in the form of @entity3907 mixtures may become a novel approach to improve the poor bioavailability of @entity4045 . Moreover, the inherent synergy from Taxus chinensis @entity3907 extracts promises a novel strategy to strengthen @entity4045 efficacy.
