Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:6.3.5.5 (CPS)
 1,262 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An automated column-switching technique coupled to isocratic high-performance liquid chromatography (HPLC) with fluorescence detection was developed for simultaneous determination of dextromethorphan and its three major metabolites, dextrorphan, hydroxymorphinan, and methoxymorphinan. After cleavage of conjugates by incubation with glucuronidasearylsulfatase at 37 degrees C for 15 h, plasma samples were injected directly into the HPLC system. Dextromethorphan and metabolites were retained on a cleanup column (10 x 4.6 mm internal diameter [ID]) filled with cyanopropyl (CN) material (Hypersil CPS, 10-microns article size) while interfering proteins and lipids were washed to waste. After column switching, the drugs were eluted from the cleanup column and separated on Spherisorb CN material (5-microns particle size, column size 250 x 4.6 mm ID). Fluorescence detection was carried out with an excitation wavelength of 220 nm and an emission wavelength of 305 nm. Sample cleanup and HPLC separation were completed within 20 min. Regression analyses found linearity (r > 0.99) between drug concentration and detector response over a wide range-5-220 ng/ml for dextromethorphan, 5-550 ng/ml for dextrorphan, 5-500 ng/ml for hydroxymorphinan, and 5-200 ng/ml for methoxymorphinan. The limit of quantification was approximately 5 ng/ml, and the recovery was > 90% for all compounds. At concentrations of 20-500 ng/ml, the intra- and interassay coefficients of variation ranged from 3.5 to 14.6% and from 7.0 to 14.0%, respectively. The method is suitable for in vivo phenotyping of CYP2D6 activity, which catalyzes the O-demethylation of dextromethorphan to dextrorphan, and is also applicable to pharmacokinetic studies in man.
Ther Drug Monit 1996 Jun
PMID:Automated determination of dextromethorphan and its main metabolites in human plasma by high-performance liquid chromatography and column switching. 873 72

BACKGROUND Although platinum-based chemotherapy is the most effective strategy for esophageal cancer, toxicity and drug resistance limit the dose administration and the application of chemotherapy. Capilliposide C (CPS-C) is isolated from the Chinese herb Lysimachia capillipes Hemsl and is approved to be effective against carcinomas. However, the activity of CPS-C against esophageal cancer remains unclear. The present study was conducted to assess the chemosensitizing effects of CPS-C for enhancing the therapeutic efficacy of oxaliplatin in esophageal squamous carcinoma cells and explore the underlying mechanism. MATERIAL AND METHODS Human esophageal squamous cell carcinoma (ESCC) TE-1 and TE-2 were used. Several in vitro and in vivo analyses were carried out, including MTT, Annexin V/PI, Western blot, and TUNEL and immunohistochemistry in a xenograft model. RESULTS CPS-C significantly enhanced the proliferative inhibition and apoptotic effect of oxaliplatin in ESCC cells. Oxaliplatin combined with CPS-C decreased the expressions of PI3K, phospho-Akt, phospho-mTOR, Bcl-2, and Bcl-XL, and increased the expression of Bax and caspase-3 significantly compared to oxaliplatin-only treatment. Furthermore, in the ESCC xenograft model, CPS-C significantly enhanced the anti-cancer effects and apoptosis of oxaliplatin. CONCLUSIONS The results indicated that CPS-C enhanced the anti-proliferative and apoptotic effect of oxaliplatin by modulating the PI3K/Akt/mTOR pathway on ESCC in vitro and in vivo.
Med Sci Monit 2017 May 02
PMID:Capilliposide C Sensitizes Esophageal Squamous Carcinoma Cells to Oxaliplatin by Inducing Apoptosis Through the PI3K/Akt/mTOR Pathway. 2846 55