Search

Abstract: Arctiin, an important lignan compound in Fructus Arctii, has been reported to possess various kinds of bioactivities. Previous studies on the pharmacokinetic of arctiin after oral administration showed that it had a rapid absorption phase followed by a sharp but lasting disappearance. To gain deep insight into the action mechanism of arctiin, the excretion and metabolism of arctiin in vivo should be further studied. In this paper, three metabolites were isolated and identified in rat feces as (−)-enterolactone (M-1), (−)-arctigenin (M-2) and [(2R,3R)-2-(3′-hydroxybenzyl)-3-(3″,4″-dimethoxybenzyl)-butyrolactone] (M-3). Based on the structures of three metabolites, possible metabolic pathways of arctiin in rats are proposed. At the same time, the cumulative excretion rate of arctiin and its metabolites in rat urine and feces were determined, indicating that arctiin was excreted 19.84% in urine and 1.80% in feces, respectively, enterolactone, the most main metabolite, was excreted 35.80% in feces. These results provide very important information for understanding the metabolism and excretion of arctiin in vivo and speculating its action mechanism, they can provide useful information and reference for further metabolic investigations on arctiin in humans. [Copyright &y& Elsevier]

Abstract: It is difficult to develop injectable sustained delivery systems for herbal medicines because of their composition complexity. Encapsulating various compounds with different physiochemical properties and achieving their synchronized and sustained release seem too hard to realize. In this paper, an injectable nanoparticulate system based on an mPEG–PLGA–mPEG (PELGE) platform was prepared for co-encapsulation and sustained release of four active components (ginkgolides A, B, C and bilobalide) in Ginkgo biloba extract. Different carriers were screened by macrophage uptake experiment for their ability to be long-circulation. Drug loaded nanoparticles were prepared with 10% PEG2000 modified PLGA by a co-precipitation method. The encapsulation efficiency of the total ginkgo terpenes (GT) in the optimal formulation was 78.84±2.06% with a loading dose of 11.90±0.31mg/150mg PELGE. The particles exhibited a spherical shape with a mean diameter of 123.3±44.0nm and zeta potential of −30.86±2.49mV. Sustained and synchronized release of the four components from PELGE nanoparticles was observed both in vitro and in vivo, which was mainly contributed to the long circulation of PEGylated nanoparticles and the slow degradation of PLGA. The half-life time of the four terpenoid compounds were also significantly improved by incorporation into PELGE nanoparticles. The results indicate that a PELGE nanoparticle is a promising carrier system for sustained and synchronized release of herbal medicines containing multiple components. [Copyright &y& Elsevier]