Ethnopharmacological relevance: Polygonum multiflorum is an important traditional Chinese medicine used for health promotion and disease treatment. One major bioactive compound in P. multiflorum is a stilbene glycoside (2,3,5,4'-tetrahydroxystilbene-2-O-β-d-glucoside, PM-SG), which possesses antioxidative, anti-inflammatory and endothelial-protective activities.
Materials and methods: The purpose of the present study was to investigate in vivo pharmacokinetics and tissue distribution of PM-SG after oral administration of Polygonum multiflorum extract to rats by using a reversed-phase high-performance liquid chromatography coupled with liquid-liquid phase extraction. The pharmacokinetic parameters were determined using both compartmental and non-compartmental analyses.
Results: All calibration curves for PM-SG in rat plasma and tissues were linear (all r(2)>0.99) over the range of 0.27-185.00 μg/ml. The intra- and inter-day variations were less than 3% at concentration range of 8.7-131.2 μg/ml and good overall recoveries (97.7-101.5%) were obtained at the same range. The maximum concentration (C(max)) and the time to reach this concentration (T(max)) of PM-SG were 31.9 μg/ml and 40.0 min, respectively. The pharmacokinetic profiles estimated by fitting two-compartment and non-compartment models revealed that PM-SG was rapidly absorbed into the body fluids and widely distributed throughout the body, with great efficiency of utility, followed by quick elimination. The highest PM-SG levels were detected in liver and lungs (90.3 ± 20.8 μg/g and 86.8 ± 9.0 μg/g, respectively) whereas little in brain and testes, indicating PM-SG can hardly penetrate the blood-brain and blood-testicle barriers.
Conclusions: This was the first report on the favorable pharmacokinetic profiles of PM-SG in rat plasma and tissues after oral administration. It may provide a meaningful basis for clinical application of such a bioactive compound of herbal medicines.
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