Nifedipine gastrointestinal therapeutic system: an overview of its antiatherosclerotic effects

Pharmacokinetics of Nifedipine-Sustained Release Tablets in Healthy Subjects After a Single Oral Administration: Bioequivalence Analysis and Food Effects

We compared newly developed delayed-release oral tablets (test) of 30-mg nifedipine (NFP) with its marketed counterpart (30 mg; reference) in healthy adult Chinese volunteers to assess the former's bioequivalence. This was a randomized, open-label, four-period, crossover trial study including fasting and fed trials. The participants were randomly administered test or reference formulations (1:1 ratio) throughout each period, with a 7-day washout period. In the next session, they were administered the alternate products. Liquid chromatography-tandem mass spectrometry and WinNonlin software were used to evaluate the bioequivalence of the maximum plasma concentration (Cmax ) of NFP and the area under the concentration-time curve (AUC). In total, 46 and 48 people participated in the fasting and postprandial trials. In both groups, the 90% confidence intervals of geometric mean ratios of Cmax , AUC from time zero to time t, and AUC from time zero to infinity were in the equivalence range (80%-125%). When NFP was administered concomitantly with a high-fat meal, time to maximum concentration was approximately twofold earlier, absorption was approximately 4.8% less, and Cmax exhibited a slight change relative to those under fasting conditions. Moreover, no serious adverse events were recorded in the participants. The present findings confirm the bioequivalence of test and reference formulations of NFP tablets under fasting and postprandial conditions.

Comparison of the effects on maternal endothelial cell activation: an in vitro study of anti-hypertensive drugs clinically used in pre-eclampsia

Endothelial cell dysfunction in pregnancy, which can be induced by placental factors, is the fundamental component of the pathogenesis of pre-eclampsia. The dysfunctional vascular endothelium disrupts the balance of vasodilatory and vasoconstrictive factors, resulting in increasing blood pressure. There is currently no effective treatment for pre-eclampsia and effective control of hypertension may reduce neonatal morbidity and mortality by prolonging gestation, especially in cases of early onset disease. To date methyldopa, labetalol, nifedipine and metoprolol are recommended for controlling blood pressure in pre-eclampsia. All of these drugs have different mechanisms of action. In this in vitro study we investigated whether different types of anti-hypertensive drugs could have different effects on improving maternal endothelial cell dysfunction. Endothelial cells (HMEC-1) were exposed to phorbol-12-myristate-13-acetate (PMA) or pre-eclamptic sera or extracellular vesicles (EVs) derived from pre-eclamptic placentae, in the presence of each of the studied anti-hypertensive drugs (methyldopa, labetalol, nifedipine and metoprolol) or placebo for 24 h. Endothelial cell-surface adhesion molecule (ICAM-1) and monocyte adhesion were measured. The expression of cell-face ICAM-1 by HMEC-1 cells and THP-1 monocyte adherent to HMEC-1 that were exposed to three separate well-known activators of endothelial cells in the presence of four anti-hypertensive drugs was significantly reduced regardless of the dose. However, the effect on the reduction of ICAM-1 expression and monocyte adhesion was not significantly different between the four medications. Our data suggest that the beneficial effect on improving endothelial cell function by these commonly prescribed anti-hypertensive drugs is seemingly independent of the anti-hypertensive mechanisms of the medication.

Differential gene expression profiles in spontaneously hypertensive rats induced by administration of enalapril and nifedipine

Enalapril and nifedipine are used as antihypertensive drugs; however, the therapeutic target molecules regulated by enalapril and nifedipine have yet to be fully identified. The aim of this study was to identify novel target genes that are specifically regulated by enalapril and nifedipine in tissues from spontaneously hypertensive rats (SHR) using DNA microarray analysis. We found that administration of SHR with enalapril and nifedipine differentially regulated 33 genes involved in the pathogenesis of cardiovascular diseases. Furthermore, we identified 16 genes that have not previously been implicated in cardiovascular diseases, including interleukin-24 (IL-24). Among them, exogenous administration of IL-24 attenuated the expression of vascular inflammation and hypertension-related genes induced by H2O2 treatment in mouse vascular smooth muscle (MOVAS) cells. This study provides valuable information for the development of novel antihypertensive drugs. In addition, the genes identified may be of use as biomarkers and therapeutic targets for cardiovascular diseases, including hypertension.

Calcium channel blockers prevent endothelial cell activation in response to necrotic trophoblast debris: possible relevance to pre-eclampsia

AIMS

Pre-eclampsia is characterized by endothelial activation, which is triggered by placental factor(s). One such factor may be trophoblastic debris that is shed into the maternal blood to become trapped against the maternal pulmonary endothelium. Phagocytosis of necrotic trophoblastic debris (NTD) induces endothelial cell activation with increased secretion of interleukin-6 (IL-6) and transforming growth factor β1 (TGFβ1), which may induce systemic endothelial cell activation. In addition to its effects on vascular smooth muscle, evidence suggests that nifedipine may also affect the endothelium, contributing to the therapeutic benefits of the drug. We investigated whether nifedipine could reverse the endothelial cell activation induced by NTD.

METHODS AND RESULTS

Trophoblastic debris was collected from placental explants and exposed to endothelial cells with or without nifedipine, verapamil, or a nitric oxide (NO) donor for 24 h. Endothelial cell activation was measured by cell-surface intracellular adhesion molecule-1 and E-selectin, as well as monocyte adhesion. The activation of endothelial cells exposed to NTD or sera from pre-eclamptic women was significantly reduced by nifedipine or verapamil. In addition, the increases in the levels of IL-6 or TGFβ1 in conditioned media from endothelial cells following phagocytosis of NTD were significantly reduced by nifedipine. These actions of nifedipine were reversed by the NO synthetase inhibitor l-NAME and mimicked by a NO donor.

CONCLUSION

Our results suggest that calcium channel blockers may have a direct effect upon endothelial cells, reducing the endothelial cell activation that is a key pathogenic feature of pre-eclampsia. This action may be mediated, in part, by NO.