Nuclear-targeting TAT-PEG-Asp8-doxorubicin polymeric nanoassembly to overcome drug-resistant colon cancer.

AIM: Drug efflux-associated multidrug resistance (MDR) is a main obstacle to effective cancer chemotherapy. Large molecule drugs are not the substrates of P-glycoprotein, and can circumvent drug efflux and be retained inside cells. In this article we report a polymer-drug conjugate nanoparticulate system that can overcome MDR based on size-related exclusion effect. METHODS: Doxorubicin was coupled with the triblock polymeric material cell-penetrating TAT-PEG-poly(aspartic acid). The amphiphilic macromolecules (termed TAT-PEG-Asp8-Dox) could self-assemble into nanoparticles (NPs) in water. The antitumor activity was evaluated in drug-resistant human colon cancer HCT8/ADR cells in vitro and in nude mice bearing HCT8/ADR tumor. RESULTS: The self-assembling TAT-PEG-Asp8-Dox NPs were approximately 150 nm with a narrow particle size distribution, which not only increased the cellular uptake efficiency, but also bypassed P-glycoprotein-mediated drug efflux and improved the intracellular drug retention, thus yielding an enhanced efficacy for killing drug-resistant HCT8/ADR colon cancer cells in vitro. Importantly, the TAT-PEG-Asp8-Dox NPs enhanced the intranuclear disposition of drugs for grater inhibition of DNA/RNA biosynthesis. In nude mice bearing xenografted HCT8/ADR colon cancers, intravenous or peritumoral injection of TAT-PEG-Asp8-Dox NPs for 22 d effectively inhibited tumor growth. CONCLUSION: TAT-PEG-Asp8-Dox NPs can increase cellular drug uptake and intranuclear drug delivery and retain effective drug accumulation inside the cells, thus exhibiting enhanced anticancer activity toward the drug-resistant human colon cancer HCT8/ADR cells.

HepG2 cells biospecific extraction and HPLC-ESI-MS analysis for screening potential antiatherosclerotic active components in Bupeuri radix.

HepG2 cells biospecific extraction method and high performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS) analysis was proposed for screening of potential antiatherosclerotic active components in Bupeuri radix, a well-known Traditional Chinese Medicine (TCM). The hypothesis suggested that when cells are incubated together with the extracts of TCM, the potential bioactive components in the TCM should selectively combine with the receptor or channel of HepG2 cells, then the eluate which contained biospecific component binding to HepG2 cells was identified using HPLC-ESI-MS analysis. The potential bioactive components of Bupeuri radix were investigated using the proposed approach. Five compounds in the saikosaponins of Bupeuri radix were detected as these components selectively combined with HepG2 cells, among these compounds, two potentially bioactive compounds namely saikosaponin b1 and saikosaponin b2 (SSb2) were identified by comparing with the chromatography of the standard sample and analysis of the structural clearance characterization of MS. Then SSb2 was used to assess the uptake of DiI-high density lipoprotein (HDL) in HepG2 cells for antiatherosclerotic activity. The results have showed that SSb2, with indicated concentrations (5, 15, 25, and 40 µM) could remarkably uptake dioctadecylindocarbocyanine labeled- (DiI) -HDL in HepG2 cells (Vs control group, *P<0.01). In conclusion, the application of HepG2 biospecific extraction coupled with HPLC-ESI-MS analysis is a rapid, convenient, and reliable method for screening potential bioactive components in TCM and SSb2 may be a valuable novel drug agent for the treatment of atherosclerosis.

Development of determination of four analytes of Zhi-Shao-San decoction using LC-MS/MS and its application to comparative pharmacokinetics in normal and irritable bowel syndrome rat plasma.

Zhi-Shao-San (ZSS), a traditional Chinese medicinal prescription, has been clinically used for the treatment of irritable bowel syndrome (IBS) for centuries. A comparative study was designed and conducted to compare the pharmacokinetic differences between paeoniflorin naringin, hesperidin and neohesperidin after oral administration of ZSS decoction to normal rats and IBS rats induced by acetic acid and restraint stress. Further, an efficient, sensitive and selective liquid chromatography/tandem mass spectrometry for the simultaneous determination of four analytes of ZSS decoction in rat plasma was developed and validated. The validated method was successfully applied to comparison of pharmacokinetic profiles of analytes in rat plasma. The results showed that the absorptions of naringin, hesperidin and neohesperidin in IBS group were all significantly higher than those in normal group and no obvious difference was seen for paeoniflorin between the two groups, which is helpful for improving clinical therapeutic efficacy and further pharmacological studies of ZSS.

Acute stress show great influences on liver function and the expression of hepatic genes associated with lipid metabolism in rats.

BACKGROUND: The theory of Chinese medicine believes rage harms normal liver function, namely 'raged impairing liver' in short. The purpose of this study is to investigate the impact of acute stress on liver lipid metabolism in rats. METHODS AND RESULTS: Comparison of liver function indicators, serum lipid level of rats under acute stress and normal rats, as well as detection of liver tissue in the SR - BI, ABCG5 and ABCG8 protein and gene expression changes. Acute stressed rats had shown a lower serum levels of albumin (P<0.01), HDL- cholesterol (P<0.01) than normal rats, with higher serum levels of globulin (P<0.01) and LDL-cholesterol (P<0.05). Acute stressed rat's liver tissue exhibited a lower protein expression of ABCG5 (P<0.05), ABCG8 (P<0.01) and a higher level of SR-BI (P<0.05), compared with to normal rats. Furthermore, liver gene expression of ABCG5 (P<0.01) and ABCG8 (P<0.05) were lower in acute stressed rats than in normal rats, while SR-BI was higher in acute stressed rats than in normal rats (P<0.01). CONCLUSIONS: Acute stress had a direct influence on rat's liver lipid metabolism.

[Application of Doehlert design for compatibility research of Dachengqi decoction].

OBJECTIVE: To study the compatibility of dosage change of Zhishi, Houpo and Mangxiao affecting the yields of Anthraquinone components in Dachengqi decoction. METHOD: Response surface methodology (RSM) with Doehlert design was adopted to evaluate the yields of Anthraquinone components in Dachengqi decoction by dosage change of Zhishi, Houpo and Mangxiao and the analysis time was shorten through a desirability function. RESULT: Results show that Anthraquinone components were got a high yields when the dosage ratio of Dachengqi decoction were compatible as follows: Dahuang-Zhishi-Houpo-Mangxiao (1:4:2. 31:2). CONCLUSION: The Doehlert design with a desirability function, which allow a sequential response methodology, is a good methods, and, of cause, the mathematical model can be further extended and applied to the compatibility research of Chinese material medicine.

[Determination of apparent oil-water partition coefficient of andrographolide and dehydroandrographolide and effect of pH on them].

OBJECTIVE: To determine the apparent n-octanol-water/buffer partition coefficient of andrographolide and dehydroandrographolide. METHODS: The apparent n-octanol-water/buffer partition coefficients of andrographolide and dehydroandrographolide were measured by shaking flask method. The concentrations of andrographolide and dehydroandrographolide were analyzed by HPLC method. RESULTS: The Papp of andrographolide and dehydroandrographolide were 3.90 (log Papp = 0.59) and 19.75 (log Papp = 1. 30) in water at 37 degrees C, respectively. CONCLUSIONS: The apparent n-octanol-buffer partition coefficients of andrographolide and dehydroandrographolide are influenced by pH, and the higher pH may decrease the apparent n-octanol-buffer partition coefficients of them. Andrographolide has the highest partition coefficient in pH6, and dehydroandrogapholide in pH5.

Development and full validation of a sensitive quantitative assay for the determination of clemastine in human plasma by liquid chromatography-tandem mass spectrometry.

A sensitive high-performance liquid chromatography-tandem mass spectrometry (LC/MS/MS) method was developed and validated for the determination of clemastine in human plasma. After having been extracted from plasma samples by ethyl acetate, clemastine and internal standard, diphenhydramine, were separated on a C(18) column. Detection was performed on Thermo Finnigan TSQ Quantum triple quadrupole mass spectrometer by selected reaction monitoring (SRM) mode via electrospray ionization (ESI) source. The method was linear in the concentration range of 5.0-1000.0 pg/ml for clemastine. The intra- and inter-day precisions were within 13.4% and the deviations were between -1.1% and 5.6%. The fully validated LC/ESI-MS/MS method has been successfully applied to the preliminary pharmacokinetic study in healthy male Chinese volunteers.

[Study on the quantitative change of anthraquinonoids of Rhei in the preparation of dachengqi].

OBJECTIVE: To study the scientific evidence of the traditional preparation of Dachengqi: "Boiling Aurantii Immaturus and Magnoliae Officinalis first, and then adding Rhei to decoct together. Discarding the dregs, adding Natrii Sulfas into the decoction and drinking the upper solution when the Natrii Sulfas has dissolved completely". METHOD: The concentrations of free and combined anthraquinonoids(emodin, rhein, chrysophanol, physcion) in different decoctions were determined with HPLC method respectively. RESULT: When Natrii Sulfas, Aurantii Immaturus and Magnolias Officinalis are decocted with Rhei in different schemes, the concentrations of anthraquinonoids were changed regularly. CONCLUSION: The scientific evidence of traditional preparation method greatly increased the concentrations of the active components in Dachengqi.