Time Course Expression Analysis of 1[2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oyl]imidazole Induction of Cytoprotection in Human Endothelial Cells.

1[2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oyl]imidazole (CDDO-Im), a synthetic derivative of oleanolic acid that exhibits antioxidant and anti-inflammatory activity in several animal and in vitro models, has been shown to be beneficial if given after injury. Although induction of heme oxygenase 1 appears to be a major effector of cytoprotection, the mechanism by which the overall effect is mediated is largely unknown. This study evaluated temporal gene expression profiles to better characterize the early transcriptional events and their relationship to the dynamics of the cytoprotective response in human umbilical vein endothelial cells (HUVEC) to CDDO-Im. Time-course gene expression profiling was performed on HUVEC treated with CDDO-Im for 0.5, 1, 3, 6, and 24 hours. More than 10 000 genes were statistically altered in their expression in at least 1 time point across the time course. Large alterations in immediate-early gene expression were readily detectable within 0.5 hour after administration of CDDO-Im

Cytoprotection of human endothelial cells from menadione cytotoxicity by caffeic acid phenethyl ester: the role of heme oxygenase-1

Caffeic acid phenethyl ester (CAPE), derived from various plant sources, has been shown to ameliorate ischemia/reperfusion injury in vivo, and this has been attributed to its ability to reduce oxidative stress. Here we investigated the cytoprotection of CAPE against menadione-induced oxidative stress in human umbilical vein endothelial cells (HUVEC) to evaluate potential gene expression involvement. CAPE exhibited dose-dependent cytoprotection of HUVEC. A gene screen with microarrays was performed to identify the potential cytoprotective gene(s) induced by CAPE. Heme oxygenase-1 (HO-1) was highly upregulated by CAPE and this was confirmed with reverse transcriptase polymerase chain reaction (RT-PCR) and western blotting. Inhibition of HO-1 activity using the HO-1 inhibitor tin protoporphyrin IX (SnPPIX), resulted in loss of cytoprotection. Carbon monoxide, one of HO-1 catabolic products appeared to play a small role in CAPE protection. Caffeic acid, a potential metabolite of CAPE with similar free radical scavenging ability, however, didn\u27t show any cytoprotective effect nor induce HO-1. These findings suggest an important role of HO-1 induction in CAPE cytoprotection against oxidant stress, which may not relate to CAPE structural antioxidant activity nor to its traditional enzymatic activity in decomposing heme but to a yet to be determined activity

Quantitative determination of fluorinated caffeic acid phenethyl ester derivative from rat blood plasma by liquid chromatography-electrospray ionization tandem mass spectrometry

The quantitative determination of caffeic acid phenethyl ester (CAPE) and its fluorinated derivative (FCAPE) from rat plasma using ultra-performance liquid chromatography with electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS) is reported. CAPE and FCAPE were extracted using ethyl acetate in the presence of methyl caffeate (MC) as internal standard. Separation was achieved using a C(18) column (2.1 mm x 50 mm, 1.7 microm) and gradient elution with water and acetonitrile containing 0.2% and 0.1% formic acid, respectively. A non-linear response over a broad concentration range (1-1000 ng/ml, r(2)\u3e0.995 using a quadratic regression model and 1/concentration weighting) was obtained. The inter-day and intra-day variability for CAPE and FCAPE were found to be less than 14.2% and 9.5%, respectively. Data are presented to illustrate the practicality of the method for the pharmacokinetic evaluation of CAPE and FCAPE after intravenous administration to rats

Pharmacokinetics of caffeic acid phenethyl ester and its catechol-ring fluorinated derivative following intravenous administration to rats

The pharmacokinetic profiles of caffeic acid phenethyl ester (CAPE) and its catechol-ring fluorinated derivative (FCAPE) were determined in rats after intravenous administration of 5, 10 or 20 mg/kg for CAPE and 20 mg/kg for FCAPE, respectively. The plasma concentrations of CAPE and FCAPE were measured using a validated liquid chromatography tandem mass spectrometric method. The pharmacokinetic parameters were estimated using non compartmental analysis (NCA) and biexponential fit. The results showed that the area under the plasma concentration-time curve for CAPE treatment increased in a proportion greater than the increase in dose from 5 to 20 mg/kg of CAPE. Total body clearance values for CAPE ranged from 42.1 to 172 ml/min/kg (NCA) and decreased with the increasing dose of CAPE. Similarly, the volume of distribution values for CAPE ranged from 1555 to 5209 ml/kg, decreasing with increasing dose. The elimination half-life for CAPE ranged from 21.2 to 26.7 min and was independent of dose. That FCAPE was distributed extensively into rat tissues and eliminated rapidly was indicated by a high value of volume of distribution and similar short elimination half-life as that of CAPE

Scientific Perspectives on Extending the Provision for Waivers of In vivo Bioavailability and Bioequivalence Studies for Drug Products Containing High Solubility-Low Permeability Drugs (BCS-Class 3)

Recently, there has been increased interest in extending the provision for waivers of in vivo bioavailability and bioequivalence (BA–BE) studies that appeared in the guidance published by the Food and Drug Administration (FDA) (1) to pharmaceutical products containing Class 3 drugs (High solubility–Low Permeability). The extension of the Biopharmaceutics Classification System (BCS) to Class 3 drugs is meritorious because of its impact on public health policy considerations. The rate limiting step in the absorption of Class 3 drugs is the permeability through the intestinal membrane. This commentary will focus its attention on the scientific considerations which need to be examined to assess the risk and the benefit prior to granting a waiver of in vivo bioavailability and/or bioequivalence studies for Class 3 drugs. It will examine the forces affecting the interconnectivity of the neuronal, immunological and hormonal systems in the gastrointestinal tract that may affect its permeability and functionality. It will also challenge the assumption that in vitro dissolution and in vitro permeability studies in tissue cultures in the presence and absence of excipients are good predictors for in vivo dissolution and in vivo permeability which are at the heart of the BCS