Simultaneous determination of puerarin and its active metabolite in human plasma by UPLC-MS/MS: application to a pharmacokinetic study.

A rapid, selective and sensitive ultra-performance liquid chromatography (UPLC)-tandem mass spectrometry method about the simultaneous determination of puerarin and its major active metabolite, daidzein, in human plasma was developed and validated in order to investigate the pharmacokinetics (PKs) of Gegen after the usual oral dose administration to human. Chromatography was carried out on a Kinetex C18 column (2.1mm×50mm, 1.7µm) using 0.05% acetic acid in water and 0.05% acetic acid in methanol as mobile phase with a gradient elution. Liquid-liquid extraction with ethyl acetate in acidic condition could remove the interference and minimize the matrix effect of human plasma. The lower limit of quantification in human plasma was 0.2ng/mL for both of compounds, puerarin and daidzein. The calibration curves for puerarin and daidzein in human plasma were linear over all the concentration range of 0.2-100ng/mL with correlation coefficients greater than 0.998. This assay procedure was successfully applied to the PKs of puerarin and daidzein, after the usual oral dose of Gegen extract powder (2.56g, containing 9.984mg puerarin) in human subjects.

In vitro and in vivo toxicities of sediment and surface water in an area near a major steel industry of Korea: endocrine disruption, reproduction, or survival effects combined with instrumental analysis.

The influence of industrial and/or municipal contaminant inputs on the aquatic environment of Pohang, Korea was investigated, with a focus on bioassay combined with instrumental analysis. Pohang is the most heavily populated city in Gyeongsangbuk-do province of Korea, with more than half a million residents, and also hosts the nation's biggest steel manufacturer and related industries. Sediment (n=15) and surface water samples (n=17) were collected from Hyeongsan River which runs across the Pohang city, in two separate events, i.e., June 2010 and February 2011. Sediment samples were first Soxhlet-extracted (raw extract) and were measured for estrogenicity using H295R cell line, and also analyzed for alkylphenols (APs), bisphenol A (BPA), PAHs, and PCBs. For sediment samples which exhibited greatest effects in the cell line, further fractionation was performed into non-polar, mid-polar, and polar portions. In surface water samples, heavy metals were also analyzed. Among 15 sediment samples, station S2 near the steel industry complex and station M3 near the municipal area showed the greatest sex hormone changes, and these changes were generally explained by the fractions which contained APs and BPA. Principal component analysis (PCA) however suggests that chemicals that were not analyzed in the present study would better explain endocrine disruption capacity of sediments. In water samples, adverse effects on hatchability and growth of Japanese medaka fish, and on Daphnia reproduction were noted following exposure to six water samples collected from stations near industrial and municipal areas. Several heavy metals and nonylphenol (NP) concentrations exceeded surface water quality guidelines, suggesting adverse effects of contamination inputs from both industrial and municipal activities. Observed estrogenicities in stations such as S2 and M3 warrant further investigations on longer term ecosystem impacts near industrial and municipal areas. The levels of major organic chemicals in sediments are quite comparable to those reported in ~10 years ago, emphasizing a need for source control.