Biopharmaceutical Characterization and Bioavailability Study of a Tetrazole Analog of Clofibric Acid in Rat.

In the current investigation, the physicochemical, biopharmaceutical and pharmacokinetic characterization of a new clofibric acid analog (Compound 1) was evaluated. Compound 1 showed affinity by lipophilic phase in 1 to 5 pH interval, indicating that this compound would be absorbed favorably in duodenum or jejunum. Also, Compound 1 possess two ionic species, first above of pH 4.43 and, the second one is present over pH 6.08. The apparent permeability in everted sac rat intestine model was 8.73 × 10-6 cm/s in duodenum and 1.62 × 10-5 cm/s in jejunum, suggesting that Compound 1 has low permeability. Elimination constant after an oral administration of 50 µg/kg in Wistar rat was 1.81 h-1, absorption constant was 3.05 h-1, Cmax was 3.57 µg/mL at 0.33 h, AUC0-α was 956.54 µ/mL·h and distribution volume was 419.4 mL. To IV administration at the same dose, ke was 1.21 h-1, Vd was 399.6 mL and AUC0-α was 747.81 µ/mL·h. No significant differences were observed between pharmacokinetic parameters at every administration route. Bioavailability evaluated was 10.4%. Compound 1 is metabolized to Compound 2 probably by enzymatic hydrolysis, and it showed a half-life of 9.24 h. With these properties, Compound 1 would be considered as a prodrug of Compound 2 with potential as an antidiabetic and anti dyslipidemic agent.

Fibrates for primary prevention of cardiovascular disease events.

BACKGROUND: Fibrates are effective for modifying atherogenic dyslipidaemia, and particularly for lowering serum triglycerides. However, evidence that fibrates reduce mortality and morbidity associated with cardiovascular disease (CVD), or overall mortality and morbidity, in the primary prevention of CVD is lacking. OBJECTIVES: This Cochrane Review and meta-analysis aimed to evaluate the clinical benefits and harms of fibrates versus placebo or usual care or fibrates plus other lipid-modifying drugs versus other lipid-modifying drugs alone for the primary prevention of cardiovascular disease (CVD) morbidity and mortality. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid), Embase (Ovid), CINAHL (EBSCO), and Web of Science (all from inception to 19 May 2016). We searched four clinical trial registers (last searched on 3 August 2016) with the help of an experienced professional librarian. We searched the databases to identify randomised controlled trials (RCTs) evaluating the clinical effects of fibrate therapy in the primary prevention of CVD events. We did not impose any language restrictions. SELECTION CRITERIA: We aimed to include all RCTs comparing the effects of fibrate monotherapy versus placebo or usual care, or fibrates plus other lipid-modifying drugs versus other lipid-modifying drugs alone. Included studies had a follow-up of at least six months for the primary prevention of CVD events. We excluded trials with clofibrate, because it was withdrawn from the market in 2002. DATA COLLECTION AND ANALYSIS: Two review authors independently screened titles and abstracts for potential study inclusion. Two review authors independently retrieved the full-text papers and extracted data. Disagreements were resolved by consensus. We calculated risk ratios (RRs) and accompanying 95% confidence intervals (CIs) for aggregate data on primary and secondary outcomes. We tested for heterogeneity with the Cochrane Q-test and used the I2 statistic to measure inconsistency of treatment effects across studies. Using the GRADE approach, we assessed the quality of the evidence and used the GRADE profiler software (GRADEpro GDT) to import data from Review Manager 5 to create 'Summary of findings' tables. MAIN RESULTS: We identified six eligible trials including 16,135 individuals. The mean age of trial populations varied across trials; between 47.3 and 62.3 years. Four trials included individuals with diabetes mellitus type 2 only. The mean treatment duration and follow-up of participants across trials was 4.8 years. We judged the risks of selection and performance bias to be low; risks of detection bias, attrition bias, and reporting bias were unclear. Reporting of adverse effects by included trials was very limited; that is why we used discontinuation of therapy due to adverse effects as a proxy for adverse effects. Patients treated with fibrates had a reduced risk for the combined primary outcome of CVD death, non-fatal myocardial infarction, or non-fatal stroke compared to patients on placebo (risk ratio (RR) 0.84, 95% confidence interval (CI) 0.74 to 0.96; participants = 16,135; studies = 6; moderate-quality of evidence). For secondary outcomes we found RRs for fibrate therapy compared with placebo of 0.79 for combined coronary heart disease death or non-fatal myocardial infarction (95% CI 0.68 to 0.92; participants = 16,135; studies = 6; moderate-quality of evidence); 1.01 for overall mortality (95% CI 0.81 to 1.26; participants = 8471; studies = 5; low-quality of evidence); 1.01 for non-CVD mortality (95% CI 0.76 to 1.35; participants = 8471; studies = 5; low-quality of evidence); and 1.38 for discontinuation of therapy due to adverse effects (95% CI 0.71 to 2.68; participants = 4805; studies = 3; I2 = 74%; very low-quality of evidence). Data on quality of life were not available from any trial. Trials that evaluated fibrates in the background of statins (2 studies) showed no benefits in preventing cardiovascular events. AUTHORS' CONCLUSIONS: Moderate-quality evidence suggests that fibrates lower the risk for cardiovascular and coronary events in primary prevention, but the absolute treatment effects in the primary prevention setting are modest (absolute risk reductions < 1%). There is low-quality evidence that fibrates have no effect on overall or non-CVD mortality. Very low-quality evidence suggests that fibrates are not associated with increased risk for adverse effects.

Methods of chromatographic determination of medicines decreasing the level of cholesterol.

With reference to common application of HPLC to routine analytical tests on medicinal products decreasing the level of cholesterol, including three compounds from this group--fenofibrate, bezafibrate and etofibrate, we developed a new method for determining two other compounds--ciprofibrate and gemfibrozil. The developed HPLC method may be used for identification and qualitative determination of selected compounds--derivatives of aryloxyalkylcarboxylic acids as well as it may be used for simultaneous separation and determination of all compounds from the group of fibrates using one column and the same methodology. The results and statistical data indicate good sensitivity and precision. The RSD value presented is equivalent to the newly developed method of determinination of ciprofibrate and gemfibrozil in the substances and medicinal products--capsules and coated tablets.

Peroxisome proliferator-activated receptor alpha agonists enhance cardiomyogenesis of mouse ES cells by utilization of a reactive oxygen species-dependent mechanism.

Peroxisome proliferator-activated receptors (PPARalpha, -beta and -gamma) are nuclear receptors involved in transcriptional regulation of lipid and energy metabolism. Since the energy demand increases when cardiac progenitor cells are developing rhythmic contractile activity, PPAR activation may play a critical role during cardiomyogenesis of embryonic stem (ES) cells. It is shown that ES cells express PPARalpha, -beta, and -gamma mRNA during differentiation of ES cells towards cardiac cells. Treatment with PPARalpha agonists (WY14643, GW7647, and ciprofibrate) significantly increased cardiomyogenesis and expression of the cardiac genes MLC2a, ANP, MHC-beta, MLC2v, and cardiac alpha-actin. Furthermore, WY14643 increased PPARalpha gene expression and the expression of the cardiogenic transcription factors GATA-4, Nkx2.5, DTEF-1, and MEF 2C. In contrast, the PPARalpha antagonist MK886 decreased cardiomyogenesis, whereas the PPARbeta agonist L-165,041 as well as the PPARgamma agonist GW1929 were without effects. Treatment with PPARalpha, but not PPARbeta, and PPARgamma agonists and MK886, resulted in generation of reactive oxygen species (ROS), which was inhibited in the presence of the NADPH oxidase inhibitors diphenylen iodonium (DPI) and apocynin and the free radical scavengers vitamin E and N-(2-mercapto-propionyl)-glycine (NMPG), whereas the mitochondrial complex I inhibitor rotenone was without effects. The effect of PPARalpha agonists on cardiomyogenesis of ES cells was abolished upon preincubation with free radical scavengers and NADPH oxidase inhibitors, indicating involvement of ROS in PPARalpha, mediated cardiac differentiation. In summary, our data indicate that stimulation of PPARalpha but not PPARbeta and -gamma enhances cardiomyogenesis in ES cells using a pathway that involves ROS and NADPH oxidase activity.

Induction and origin of hepatocytes in rat pancreas.

2-[4(2,2- Dichlorocyclopropyl )phenoxy]2-methyl propionic acid (ciprofibrate), a peroxisome proliferator , induced hepatocytes in the pancreas of adult male F-344 rats when added to their diet at a dosage of 10 mg/kg body weight for 60-72 wk. These cells are morphologically indistinguishable from hepatic hepatocytes and were usually localized adjacent to islets of Langerhans with extensions into surrounding acinar tissue. A significant increase in the volume density of peroxisomes, together with immunochemically detectable amounts of two peroxisome-associated enzymes, was observed in pancreas with hepatocytes of rats maintained on ciprofibrate. Uricase-containing crystalloid nucleoids, specific for rat hepatocyte peroxisomes, were present in pancreatic hepatocytes. These structures facilitated the identification of cells with hybrid cytoplasmic features characteristic of pancreatic acinar and endocrine cells and hepatocytes. Such cells are presumed to represent a transitional state in which pancreas specific genes are being repressed while liver specific ones are simultaneously expressed. The presence of exocrine and/or endocrine secretory granules in transitional cells indicates that acinar/intermediate cells represent the precursor cell from which pancreatic hepatocytes are derived.

Subacute exposure to N-ethyl perfluorooctanesulfonamidoethanol results in the formation of perfluorooctanesulfonate and alters superoxide dismutase activity in female rats.

Perfluorooctanesulfonamides, such as N-ethyl perfluorooctanesulfonamidoethanol (N-EtFOSE), are large scale industrial chemicals but their disposition and toxicity are poorly understood despite significant human exposure. The hypothesis that subacute exposure to N-EtFOSE, a weak peroxisome proliferator, causes a redox imbalance in vivo was tested using the known peroxisome proliferator, ciprofibrate, as a positive control. Female Sprague-Dawley rats were treated orally with N-EtFOSE, ciprofibrate or corn oil (vehicle) for 21 days, and levels of N-EtFOSE and its metabolites as well as markers of peroxisome proliferation and oxidative stress were assessed in serum, liver and/or uterus. The N-EtFOSE metabolite profile in liver and serum was in good agreement with reported in vitro biotransformation pathways in rats and the metabolite levels decreasing in the order perfluorooctanesulfonate >> perfluorooctanesulfonamide ~ N-ethyl perfluorooctanesulfonamidoacetate >> perfluorooctanesulfonamidoethanol approximately N-EtFOSE. Although N-EtFOSE treatment significantly decreased the growth rate, increased relative liver weight and activity of superoxide dismutases (SOD) in liver and uterus (total SOD, CuZnSOD and MnSOD), a metabolic study revealed no differences in the metabolome in serum from N-EtFOSE-treated and control animals. Ciprofibrate treatment increased liver weight and peroxisomal acyl Co-A oxidase activity in the liver and altered antioxidant enzyme activities in the uterus and liver. According to NMR metabolomic studies, ciprofibrate treated animals had altered serum lipid profiles compared to N-EtFOSE-treated and control animals, whereas putative markers of peroxisome proliferation in serum were not affected. Overall, this study demonstrates the biotransformation of N-EtFOSE to PFOS in rats that is accompanied by N-EtFOSE-induced alterations in antioxidant enzyme activity.

Ciprofibrate increases cholesteryl ester transfer protein gene expression and the indirect reverse cholesterol transport to the liver.

BACKGROUND: CETP is a plasma protein that modulates atherosclerosis risk through its HDL-cholesterol reducing action. The aim of this work was to examine the effect of the PPARalpha agonist, ciprofibrate, on the CETP gene expression, in the presence and absence of apolipoprotein (apo) CIII induced hypertriglyceridemia, and its impact on the HDL metabolism. RESULTS: Mice expressing apo CIII and/or CETP and non-transgenic littermates (CIII, CIII/CETP, CETP, non-Tg) were treated with ciprofibrate during 3 weeks. Drug treatment reduced plasma triglycerides (30-43%) and non-esterified fatty acids (19-47%) levels. Cholesterol (chol) distribution in plasma lipoprotein responses to ciprofibrate treatment was dependent on the genotypes. Treated CIII expressing mice presented elevation in VLDL-chol and reduction in HDL-chol. Treated CETP expressing mice responded with reduction in LDL-chol whereas in non-Tg mice the LDL-chol increased. In addition, ciprofibrate increased plasma post heparin lipoprotein lipase activity (1.3-2.1 fold) in all groups but hepatic lipase activity decreased in treated CETP and non-Tg mice. Plasma CETP activity and liver CETP mRNA levels were significantly increased in treated CIII/CETP and CETP mice (30-100%). Kinetic studies with 3H-cholesteryl ether (CEt) labelled HDL showed a 50% reduction in the 3H-CEt found in the LDL fraction in ciprofibrate treated compared to non-treated CETP mice. This means that 3H-CEt transferred from HDL to LDL was more efficiently removed from the plasma in the fibrate treated mice. Accordingly, the amount of 3H-CEt recovered in the liver 6 hours after HDL injection was increased by 35%. CONCLUSION: Together these data showed that the PPARalpha agonist ciprofibrate stimulates CETP gene expression and changes the cholesterol flow through the reverse cholesterol transport, increasing plasma cholesterol removal through LDL.

[Efficacy and safety of etofibrate in patients with non-proliferative diabetic retinopathy]. / Wirksamkeit und Sicherheit von Etofibrat bei Patienten mit nicht proliferativer diabetischer Retinopathie.

INTRODUCTION: Diabetic retinopathy is the leading cause of vision loss or blindeness in working-age adults in the developed and developing countries. No curative treatments are available for diabetic retinopathy and the most common symptomatic treatment, laser photocoagulation, provides only partial and temporary relief from the progressive vascular damage caused by this disease. Etofibrate (Lipo-Merz) is an orally-administered treatment for lipid disorders that combines fibrate and nicotinic acid in a slow-release formulation. PATIENTS AND METHODS: This report describes the results of a double-blind, randomised, placebo-controlled study, performed to evaluate the efficacy and safety of etofibrat in patients with type 2 diabetes mellitus and concomitant diabetic retinopathy. They received either placebo or 1000 mg/day etofibrate for up to 12 months. Efficacy analyses were based on visual acuity assessment and blinded expert ratings of ocular fundus pathology, as well as laboratory analyses of serum lipid parameters. RESULTS: The evaluable population comprised 296 patients, 148 in each treatment group, of whom 89% completed the study and 73% completed according to protocol. After 12 months of treatment, a significantly larger population of etofibrate-treated patients than placebo-treated patients showed improvements in ocular pathology (46% versus 32%, respectively, p < 0.001); similar findings were already apparent after 6 months of treatment (43% versus 31%, respectively p < 0.001). Etofibrate treatment also produced significant improvements in total cholesterol, LDL-cholesterol and HDL-cholesterol in comparison to the placebo treatment group. Safety evaluations (adverse events, laboratory parameters) did not reveal any clinically significant adverse effects of etofibrate in comparison to placebo. CONCLUSION: Etofibrate provides a safe and effective treatment for ocular pathology resulting from type 2 diabetes mellitus.

Etofibrate enhances 123I-LDL-binding in human liver.

Etofibrate, a combination of fibric and nicotinic acid, is successfully used for the treatment of type IIb and IV hyperlipidemia. While an up-regulation of specific low density lipoproteins (LDL) binding sites in human platelets has been demonstrated, action on LDL-binding to the liver in patients and kinetic studies rare. This study aimed to investigate the influence of twice 500mg etofibrate daily given for 6 weeks on the in vivo binding of autologous LDL to the liver in 11 patients, 6 males, 5 females; aged 37-57 years, suffering from mixed hyperlipidemia. Etofibrate enhanced in vivo liver uptake of (123)I-LDL by 16.1% at mean, shortened plasma decay of LDL and improved lipid profile: serum total cholesterol was lowered by 14.9%, LDL-cholesterol was lowered by 22.2% and high-density lipoprotein (HDL)- cholesterol was increased by 10.9%. These findings are documenting a beneficial effect of the drug at the LDL liver receptor level in vivo.

Ciglitazone induces caspase-independent apoptosis via p38-dependent AIF nuclear translocation in renal epithelial cells.

Peroxisome proliferator-activated receptor gamma (PPARgamma) agonists have been reported to induce apoptosis in a variety of cell types including renal proximal epithelial cells. However, the underlying mechanism of cell death induced by PPARgamma agonists has not been clearly defined in renal proximal tubular cells. This study was therefore undertaken to determine the mechanism by which ciglitazone, a synthetic PPARgamma agonist, induces apoptosis in opossum kidney (OK) cells, an established renal epithelial cell line. Ciglitazone treatment induced apoptotic cell death in a dose- and time-dependent manner. Ciglitazone caused a transient activation of ERK and sustained activation of p38 MAP kinase. Ciglitazone-mediated cell death was attenuated by the p38 inhibitor SB203580 and transfection of dominant-negative form of p38, but not by the MEK inhibitor U0126, indicating that p38 MAP kinase activation is involved in the ciglitazone-induced cell death. Although ciglitazone-induced caspase-3 activation, the ciglitazone-mediated cell death was not affected by the caspase-3 inhibitor DEVD-CHO. Ciglitazone-induced mitochondrial membrane depolarization and apoptosis-inducing factor (AIF) nuclear translocation and these effects were prevented by the p38 inhibitor. These results suggest that ciglitazone induces caspase-independent apoptosis through p38 MAP kinase-dependent AIF nuclear translocation in OK renal epithelial cells.

Role of the p50 subunit of NF-kappaB in vitamin E-induced changes in mice treated with the peroxisome proliferator, ciprofibrate.

Peroxisome proliferators (PPs) are a diverse class of chemicals, which cause a dramatic increase in the size and number of hepatic peroxisomes in rodents and eventually lead to the development of hepatic tumors. Nuclear factor-kappaB (NF-kappaB) is a transcription factor activated by reactive oxygen and is involved in cell proliferation and apoptosis. Previously we found that the peroxisome proliferator ciprofibrate (CIP) activates NF-kappaB and that dietary vitamin E decreases CIP-induced NF-kappaB DNA binding. We, therefore, hypothesized that inhibition of NF-kappaB by vitamin E is necessary for effects of vitamin E on CIP-induced cell proliferation and the inhibition of apoptosis by CIP. Sixteen B6129 female mice (p50+/+) and twenty mice deficient in the p50 subunit of NF-kappaB (p50-/-) were fed a purified diet containing 10 or 250mg/kg vitamin E (alpha-tocopherol acetate) for 28 days. At that time, half of the mice were placed on the same diet with 0.01% CIP for 10 days. CIP treatment increased the DNA binding activity of NF-kappaB and cell proliferation, but had no significant effect on apoptosis. Compared to wild-type mice, the p50-/- mice had lower NF-kappaB activation, higher basal levels of cell proliferation and apoptosis, and a lower ratio of reduced glutathione to oxidized glutathione (GSH/GSSG). There was approximately a 60% reduction in cell proliferation in the CIP-treated p50-/- mice fed higher vitamin E in comparison to the p50-/- mice fed lower vitamin E. Dietary vitamin E also inhibited the DNA binding activity of NF-kappaB, increased apoptosis, and increased the GSH/GSSG ratio. This study shows the effects of vitamin E on cell growth parameters do not appear to be solely through decreased NF-kappaB activation, suggesting that vitamin E is acting by other molecular mechanisms.

Pigment epithelium-derived factor is an angiogenesis and lipid regulator that activates peroxisome proliferator-activated receptor alpha.

Pigment epithelium-derived factor (PEDF) is an endogenous antiangiogenic protein that also possesses antitumor activity. The mechanisms by which PEDF exerts its actions remains poorly understood. We sought to understand the role of PEDF in hepatocellular carcinoma (HCC), a hypervascular malignancy that has been shown to upregulate enzymes involved in fatty acid synthesis. PEDF expression occurs in two HCC cell lines and is oxygen dependent. Migration studies confirm PEDF's role as an endogenous inhibitor of angiogenesis in HCC cells. Loss of PEDF in an animal model leads to hepatocyte lipid accumulation, proliferation, and cellular atypia. To investigate potential interactions with transcription factors that are involved in fatty acid metabolism and cellular proliferation, we examined PEDF's interaction with PPARalpha in vitro and its functional activity through transactivation assays. We show that PEDF binds to PPARalpha but minimally to PPARgamma. In the presence of the ligand, ciprofibrate, PEDF binding to PPARalpha decreases whereas the presence of troglitazone does not alter PEDF interactions with PPARgamma. Transfection of the PEDF gene in the presence of the PPARalpha/RXR heterodimer demonstrates transcriptional activation of PPARalpha by PEDF. These data show that PEDF regulates lipid metabolism through activation of the transcription factor PPARalpha.

Administration of ciprofibrate to lactating mothers induces PPARalpha-signaling pathway in the liver and kidney of suckling rats.

It is well known that the hypolipidemic drug ciprofibrate induces peroxisome proliferation in rodent liver, which in turn leads to the oxidative stress, and modifies some parameters related to cell proliferation and apoptosis. The administration of ciprofibrate to rats during the lactating period determined in their pups significant modifications in hepatic peroxisome enzyme activities, induction of the PPARalpha-target gene, Cyp4a10, and perturbation in cell proliferation and apoptosis, which affected the size of the liver. Moreover, this modification was associated to about two-fold induction of mRNA-PPARalpha. On the contrary, in the kidney, although a similar two-fold up-regulation of PPARalpha was detected, the induction of both peroxisomal enzyme activities and Cyp4a10 were weak, and no alterations were detected, neither in cell cycle nor in the size of the tissue. Our results indicate that the response to ciprofibrate is stronger in the liver than in the kidney of newborn rats.

Determination of etofibrate, fenofibrate, and atorvastatin in pharmaceutical preparations and plasma using differential pulse polarographic and square wave voltammetric techniques.

Etofibrate, fenofibrate, and atorvastatin were determined in their pharmaceutical preparations and human plasma using differential pulse polarographic and square wave voltammetric techniques by reduction at a dropping-mercury working electrode versus Ag/AgCl reference electrode. The reversibility of the electrode reactions was tested using cyclic voltammetry, and they were found to be irreversible reduction reactions. Optimum conditions such as pH, scan rate, and pulse amplitude were studied, and validation of the proposed methods was performed. The proposed methods proved to be accurate, precise, robust, and specific for determination of the 3 drugs. The relative standard deviation values were <2%, indicating that these methods are precise. Limits of detection and quantitation were in the ranges of 0.037-0.21 and 0.12-0.71 microg/mL, respectively, indicating high sensitivity.

Substituted tertiary phosphine Ru(II) organometallics: catalytic utility on the hydrolysis of etofibrate in pharmaceuticals.

Some new organometallics of ruthenium(II) of the type [RuCl2(COD)(CO)L] (1a-f) and [RuCl2(COD)L2] (2a-f) (where L is substituted tertiary phosphines), have been synthesized by using precursors [RuCl2(COD)(CO)(CH3CN)] (1) and [RuCl2(COD)(CH3CN)2] (2) with the substituted tertiary phosphine ligands in 1:1 and 1:2 molar ratio. The organometallics (2a-f) have been further reacted with carbonmonoxide to produce compounds of the type [RuCl2(CO)L2] (3a-f). These compounds were characterized by elemental analysis, IR, NMR (1H, 13C and 31P), mass and electronic spectral data. The catalytic activity of all these organometallics were studied and found that they are efficient catalysts for hydrolysis of etofibrate. The hydrolyzed product was separated by column chromatography and the percent yields are found in the range of 98.6-99.1%.

High performance liquid chromatographic determination of etofibrate and its hydrolysis products.

High performance liquid chromatographic (HPLC) method is presented for the determination of etofibrate (EF) and its hydrolysis products. The method was based on HPLC separation of EF from its hydrolysis products using cyanopropyl column at ambient temperature with mobile phase consisting of acetonitrile-10 mM potassium dihydrogen phosphate, pH was adjusted to 4.1 using phosphoric acid (50:50, v/v). Quantitation was achieved with UV detection at 221 nm based on peak area. The flow rate was 1.5 ml min(-1). The proposed method was used to investigate the kinetics of acidic hydrolysis process of EF at different temperatures and the apparent pseudo first-order rate constant, half-life and activation energy were calculated. The kinetics of alkaline hydrolysis process of EF using 0.01 M sodium hydroxide at different temperatures cannot be studied as the drug is rapidly hydrolyzed in alkaline medium. The pH-rate profile of hydrolysis of EF in Britton-Robinson buffer solutions within the pH range 2-10 were studied.

Effects of ciprofibrate on testicular and adrenal steroidogenic enzymes in the rat.

Testicular and adrenal steroidogenic enzymes were measured radiometrically following oral dosing of rats with ciprofibrate (2-[4-(2,2-dichlorocyclopropyl) phenoxyl]-2-methylpropinoic acid), a peroxisome proliferator. Six-week-old male Fisher 344 rats were fed a diet containing ciprofibrate (0.025%, w/w) for 3, 7, 14, 28, 56, 84, 112 or 140 days leading to a daily ciprofibrate intake of approximately 15 mg/kg body weight/day. Ciprofibrate caused a marked inhibition of testicular 3beta-hydroxysteroid dehydrogenase-isomerase (3beta-HSD) activity that was significant after 3 days and subsequently decreased to 40% of control level. Ciprofibrate treatment also reduced 17beta-hydroxysteroid dehydrogenase (17beta-HSD) activity to a lesser extent but had no effect on 17-hydroxylase (17-OHase) activity. Immunoblot analyses indicated that ciprofibrate treatment did not alter enzyme protein levels and semi-quantitative RT-PCR analysis also revealed no significant changes in testicular 3beta-HSD mRNA levels. Furthermore, in addition to the enzyme-specific effect of ciprofibrate on 3beta-HSD in the testes, a tissue-specific effect was also evident, since no significant effects of ciprofibrate were seen on the activities of 3beta-HSD or 21-OHase in the adrenal glands from the same animals.

Separation of fibrate-type antihyperlipidemic drugs by capillary electrophoresis and their quantitation in pharmaceuticals.

Six antihyperlipidemic agents-bezafibrate, ciprofibrate, clofibrate, clofibric acid, fenofibrate and gemfibrozil were separated by means of capillary electrophoresis, using unmodified fused silica tubing of 75 microm internal diameter and 87 cm length (65 cm to the UV detector at 227 nm). Migration time and selectivity were examined in differing pH of separation buffer, varying separation voltage and differing temperature. Optimal separation was achieved using 1/15 M phosphate buffer pH 10, 240 V/cm at 25 degrees C. The optimal separation conditions were then used to elaborate the method of quantitation of bezafibrate, ciprofibrate and gemfibrozil in Bezamidin, Lipanor and Gemfibral pharmaceuticals. The clofibric acid was used as internal standard. The calibration curve was constructed from 0.2 to 0.8 mg/ml of each compound and 0.5 mg/ml of internal standard. The calibration data were proved to be linear by Mandel and Lack-of-fit tests. Statistical evaluation of results proved proper recovery of elaborated method (102.42, 97.32 and 101.51%, respectively) and good repeatability (9.51, 5.52 and 11.15%, respectively). The linearity of recovery was also tested by analyzing increasing amount of the samples. Three fortified samples of each drug were also analyzed to perform additional accuracy validation.

Peroxisome proliferator-induced hepatocarcinogenesis: histochemical analysis of ciprofibrate-induced preneoplastic and neoplastic lesions for gamma-glutamyl transpeptidase activity.

Previous studies revealed that putative preneoplastic and neoplastic lesions induced in the liver by Wy-14,643, a peroxisome proliferator, were gamma-glutamyl transpeptidase (GGT) negative. For ascertainment as to whether phenotypes of foci and carcinomas induced by all peroxisome proliferators are similarly GGT negative, altered areas (AAs), neoplastic nodules (NNs), and hepatocellular carcinomas (HCCs) induced in the livers of male F344 rats by chronic dietary administration of ciprofibrate (0.025% wt/wt in chow; CAS: 52214-84-3) were analyzed histochemically for GGT activity. Eighty-nine percent of AAs, 91% of NNs, and 91% of HCCs were GGT negative. The GGT-negative property of these various hepatic preneoplastic and neoplastic lesions persisted at 8 weeks after the withdrawal of ciprofibrate treatment. The results of this study indicate that the absence of GGT activity is a common feature in hepatic lesions induced by structurally unrelated peroxisome proliferators and is not related to the drug toxicity. The proposal was made that peroxisome proliferators do not derepress the activity of the GGT gene during hepatocarcinogenesis in the rat.

[Changes in serum lipids, plasma fibrinogen and other haemostatic parameters induced by ciprofibrate action in hyperlipidemic patients with and without coronary artery disease]. / Modificaciones de los lipidos séricos, el fibrinógeno y otros parámetros hemostáticos por acción del ciprofibrato, en pacientes hiperlipidémicos con y sin enfermedad arterial coronaria.

The effects of drugs with hypolipidemic properties in the prevention of the atherothrombotic vascular disease, go further than reducing serum lipids, suggesting that there are other nonlipid-related mechanisms involved; the maintenance of appropriate haemostatic balance being one of them. The objective of this investigation was a drug intervention with ciprofibrat in hyperlipidemic people with high level of plasmatic fibrinogen with the purpose of knowing the effects of the drug over these risk factors and other haemostatic parameters. Forty people, both sexes, 20 of them apparently healthy and the other 20 with clinical and angiographic evidence of coronary artery disease, were randomized to receive 100 mg of ciprofibrat or placebo during an average of 56 weeks. All of them had a clinical exam, EKG and stress test. Laboratory exams included lipid profile, plasma fibrinogen (Fg), VII factor, vonWillebrand factor, protein C (PC) and the tissue plasminogen activator with samples taken every 8 weeks. The Ciprofibrat group showed significant changes of lipids: cholesterol -23%, triglycerides -31%, high-density lipoprotein (HDLc) +24% and very low-density lipoprotein -23%, except low-density lipoprotein -24%. The haemostatic parameters in 40 weeks showed that Fg decreased 21% (p = 0.001), decreasing to 9% at the end of the follow-up. In the placebo group the HDLc showed a 10% increase (p = 0.02), PC reduced to 20% (p = 0.01) and Fg kept blood levels close to basal line, descending 10% at the end of the follow-up. In this study, the use of ciprofibrat in patients with high risk of developing atherothrombotic events, showed efficiency and security in handling hyperlipidemia, such as keeping and appropriate haemostatic balance.