Pharmacokinetics and bioequivalence of two fenofibrate choline formulations in healthy subjects under fed and fasted condition
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OBJECTIVE: The objective of this study was to evaluate the pharmacokinetics and bioequivalence of two formulations (the original capsule ("reference") and the new tablet ("test") formulations) of 135-mg choline fenofibrate under fed and fasted conditions. MATERIALS AND METHODS: This was an open-label, randomized, single-dose, crossover bioequivalence study in healthy Korean males. A total of 40 individuals were separately enrolled in the high-fat fed and the fasting study, respectively, and were randomized in a 1:1 ratio into two sequences. Serial blood samples were collected over 72 hours after drug administration. Plasma concentrations of fenofibric acid were determined by a validated LC-MS/MS method. Pharmacokinetic (PK) parameters were estimated using noncompartmental methods. RESULTS: Overall, 37 and 35 individuals completed the fed and the fasting study, respectively, as planned. The estimated Cmax, AUC0-∞, and AUC0-last were comparable between the test and the reference formulations in both fed and fasting studies (p > 0.05). The 90% confidence intervals for the geometric mean ratios of Cmax, AUC0-∞, and AUC0-last were 0.92 - 1.06, 0.95 - 1.01, and 0.95 - 1.01 in the fed study; and 0.94 - 1.12, 0.94 - 1.00, and 0.94 - 1.00 in the fasting study, respectively. For both formulations, tmax was significantly prolonged under fed condition compared to fasting condition (p < 0.0001); all other PK parameters were comparable between the fed and the fasting studies (p > 0.05). CONCLUSION: The reference and the test formulations of 135 mg choline fenofibrate show comparable pharmacokinetic profiles of fenofibric acid under both fed and fasted conditions and are considered bioequivalent.
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WISP1 promotes non-alcoholic fatty liver disease and skeletal muscle insulin resistance via TLR4/JNK signaling.

Wnt1-inducible signaling pathway protein-1 (WISP1) is a Cyr61/CTGF/NOV (CCN) family matricellular protein involved in adipogenesis and low-grade inflammation in obesity. However, the roles of WISP1 in hepatic steatosis and insulin resistance in skeletal muscle remain elusive. Mouse primary hepatocytes and differentiated mouse skeletal muscle cells (C2C12) were treated with various concentrations of WISP1 and the functions and signaling pathways were analyzed by Western blot analysis. In vivo transfection for WISP1 knockdown was also performed to examine the effects of WISP1 on hepatic steatosis and skeletal muscle insulin resistance. Knockdown of WISP1 in high-fat diet-fed C57BL/6 mice significantly reduced (0.45-0.5%; p < 0.05) inflammation and JNK phosphorylation (45-50%; P < 0.01) and attenuated hepatic steatosis (approximately 55%; p < 0.001) and skeletal muscle insulin resistance (30-40%; p < 0.05). Treatment with WISP1 significantly induced inflammation (hepatocytes: approximately 500%; p < 0.01, C2C12 cells: approximately 500%; p < 0.01) and JNK phosphorylation (hepatocytes: approximately 200%; p < 0.01, C2C12 cells: approximately 280%; p < 0.01) in mouse primary hepatocytes and C2C12 mouse skeletal muscle cells. Moreover, it increased lipogenesis-associated gene expression (200-300%; p < 0.01) and accumulation of triglycerides (approximately 320%; p < 0.01) in hepatocytes, and suppressed insulin signaling (approximately 50%; p < 0.01) in C2C12 cells. These WISP1-induced effects were significantly abrogated in NFκB-, JNK-, and TLR4-knockdown hepatocytes (p < 0.05) and C2C12 cells (p < 0.05). These results indicate that WISP1 contributes to hepatic steatosis and skeletal muscle insulin resistance through a TLR4-activated inflammation/JNK signaling pathway and could be a useful therapeutic target for treatment of non-alcoholic fatty liver disease and type 2 diabetes.

Phosphatidylcholine Causes Lipolysis and Apoptosis in Adipocytes through the Tumor Necrosis Factor Alpha-Dependent Pathway.

A phosphatidylcholine (PPC) formulation has been used to treat cellulite; however, its underlying mechanism of action remains unclear. In this study, we demonstrated that PPC induces lipolysis and apoptosis in adipocytes, and evaluated a possible tumor necrosis factor alpha (TNFα)-dependent pathway, whereby PPC exerts these effects. For in vitro study, fully differentiated 3T3-L1 cells, mouse adipocytes were treated with various concentrations of PPC and cell apoptosis and lipolysis were assayed. For in vivo experiments, mice fed on a high-fat diet for 8 weeks were injected twice to abdominal subcutaneous fat tissues of either vehicle or PPC. We found that PPC induced lipolysis and apoptosis dose-dependently in fully differentiated 3T3-L1 cells. In addition, PPC augmented both expression and release of TNFα in a dose-dependent fashion. Induction of TNFα by PPC was associated with the stimulation of nuclear factor kappa B (NFκB)-mediated transcriptional activity. Small interfering RNA (siRNA)-mediated suppression of NFκB abrogated the effect of PPC on TNFα secretion. Suppression of TNFα with specific siRNA abrogated the effects of PPC on lipolysis and apoptosis. Through in vivo experiments, we demonstrated that PPC injection not only stimulated the local lipolysis and apoptosis, resulting in weight loss, but also induced TNFα mRNA expression and neutrophil infiltration. Furthermore, PPC injection prevented lipogenesis and suppressed the mRNA -expression of adipokines (such as adiponectin and leptin), due to the down-sizing of adipocytes. In conclusion, we suggest that PPC induces lipolysis and apoptosis in adipocytes through TNFα-dependent pathways.

Phosphatidylcholine attenuated docetaxel-induced peripheral neurotoxicity in rats.

Docetaxel is a taxane chemotherapeutic agent used in the treatment of breast cancer, prostate cancer and gastric cancer, but several side effects such as peripheral neurotoxicity could occur. The present study was designed to investigate the therapeutic potential of phosphatidylcholine (PC) on docetaxel-induced peripheral neurotoxicity. Rats were randomly divided into three groups and treated for 4 weeks. Behavioral tests were conducted to measure the effects of PC on docetaxel-induced decreases in mechanical & thermal nociceptive threshold. Biochemical tests were conducted to measure the level of oxidative stress on sciatic nerve. Histopathological and immunohistochemical experiments were also conducted to assess neuronal damage and glial activation. PC treatment significantly attenuated docetaxel-induced changes in mechanical & thermal nociceptive response latencies. PC decreased oxidative stress in sciatic nerve by increasing antioxidant levels (glutathione, glutathione peroxidase and superoxide dismutase activity). In immunohistochemical evaluation, PC treatment ameliorated docetaxel-induced neuronal damage and microglial activation in the sciatic nerve and spinal cord. Thus, PC showed protective effects against docetaxel-induced peripheral neurotoxicity. These effects may be attributed to its antioxidant properties and modulation of microglia.

Development and Validation of Simple LC-MS-MS Assay for the Quantitative Determination of Ticagrelor in Human Plasma: its Application to a Bioequivalence Study.

A sensitive, rapid, reproducible and reliable high-performance liquid chromatography-electrospray ionization tandem mass spectrometric method has been developed and fully validated for the determination of ticagrelor in human plasma using ticagrelor-d7 as an internal standard (IS) after one-step liquid-liquid extraction with ethyl acetate. Ticagrelor and IS were detected in the multiple reaction monitoring mode at m/z transition 523.4 > 127.0 and 530.4 > 127.0, respectively. Chromatographic separation was performed on a Phenomenex Luna® C18 column using a mobile phase consisting of 0.1% formic acid in water-acetonitrile (20:80, v/v) at a flow rate of 0.2 mL/min. The retention times of ticagrelor and IS were 1.03 min and 1.02 min, respectively. The calibration curve was linear [correlation coefficient (r) ≥ 0.9991] over the concentration range of 2-1,500 ng/mL. Intra- and inter-day precisions ranged from 1.0% to 4.9% and from 1.8% to 8.7%, and the accuracy ranged from 97.0% to 105.9% and from 97.5% to 102.9%, respectively. The developed method was fully validated with respect to selectivity, linearity, lower limit of quantitation, recovery, matrix effect and stability. This validated method was successfully applied to the bioequivalence study of ticagrelor in 44 healthy Korean male volunteers.

Development of a simple and sensitive HPLC-MS/MS method for determination of diazepam in human plasma and its application to a bioequivalence study.

We developed a simple, sensitive, and effective ultra-performance liquid chromatography/tandem mass spectrometry (HPLC-MS/MS) method with an electrospray ionization (ESI) interface in multiple reaction monitoring (MRM) and positive ion modes to determine diazepam concentrations in human plasma using voriconazole as an internal standard (IS). Diazepam and IS were detected at transition 285.2→193.1 and 350.2→127.1, respectively. After liquid-liquid extraction (LLE) using 1.2 ml of ethyl acetate:n-hexane (80:20, v/v), diazepam and IS were eluted on a Phenomenex Cadenza CD-C18 column (150 × 3.0 mm, 3 µm) with an isocratic mobile phase (10 mM ammonium acetate in water:methanol [5:95, v/v]) at a flow rate of 0.4 mL/min. The peak retention time was 2.32 min for diazepam and 2.01 min for IS, respectively. The lower limit of quantitation (LLOQ) was 0.5 ng/mL (S/N > 10) using 50 µL of plasma, and no interferences were observed in chromatograms. Our analytical method was fully validated and successfully applied to a bioequivalence study of two formulations of diazepam in healthy Korean volunteers.