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The phenotype shifting of vascular smooth muscle cells (VSMCs) was indicated to play a role during the initial stage of atherosclerotic plaque formation by facilitating extracellular matrix deposition. This study was aimed at investigating the involvement of the apoptosis signal-regulating kinase 1 (ASK1) /mitogen-activated protein kinase (MAPK) kinases (MKKs) /p38 MAPK pathway in the advanced glycation end product (AGE) -induced fibrotic response of VSMCs. The effect of the novel ASK1 inhibitor AGI-1067 was also studied.Cultured human coronary smooth muscle cells (HCSMCs) were exposed to AGEs. AGI-1067 and siRNAs silencing mkk3, mkk6, and p38 mapk were used to treat the cells. The activation of MKK3, MKK6, and p38 MAPK was assessed by immunoblotting. Fibrotic response was assessed by the fluorescence immunohistochemistry staining of collagen I and collagen VIII. Activation of immunoprecipitation determined the association of ASK1 and its inhibitor thioredoxin. A kinase assay was used to determine ASK1 activity.AGE incubation significantly activated ASK1, MKK3, and MKK6, which led to activation of p38 MAPK, resulting in upregulated fibrotic response in HCSMCs. However, siRNAs knocking down mkk3, mkk6, and p38 mapk impaired this fibrotic response. AGI-1067 administration not only dramatically inhibited the activation of ASK1/MKKs/p38 MAPK but also suppressed the expression of the downstream proteins, including transforming growth factor-β1, connective tissue growth factor, collagen I, and collagen VIII in HCSMCs exposed to AGEs.The ASK1/MKKs/p38 MAPK pathway was activated by AGEs, leading to the fibrotic response in VSMCs. AGI-1067 reversed this process by maintaining the inactive state of ASK1.

Succinobucol is a phenolic antioxidant with anti-inflammatory and antiplatelet effects. Given the importance of oxidant stress in modulating platelet-platelet and platelet-vessel wall interactions, the aim of this study was to establish if antioxidant activity was responsible for the antiplatelet activity of succinobucol. Platelet aggregation in response to collagen and adenosine diphosphate (ADP) was studied in rabbit whole blood and platelet-rich plasma using impedance aggregometry. The effect of oxidant stress on aggregation, platelet lipid peroxides, and vascular tone was studied by incubating platelets, washed platelets or preconstricted rabbit iliac artery rings respectively with a combination of xanthine and xanthine oxidase (X/XO). To study the effect of succinobucol in vivo, anaesthetized rats were injected with up to 150 mg/kg succinobucol and aggregation measured in blood removed 15 mins later. Succinobucol (10 -5 -10 -4 M) significantly attenuated platelet aggregation to collagen and ADP in whole blood and platelet-rich plasma. X/XO significantly increased aggregation to collagen and platelet lipid peroxides and this was reversed by succinobucol. Addition of X/XO to denuded rabbit iliac arteries caused a dose-dependent relaxation which was significantly inhibited by succinobucol. In vivo administration up to 150 mg/kg had no effect on heart rate or mean arterial blood pressure but significantly inhibited platelet aggregation to collagen ex vivo. In conclusion, succinobucol displays anti-platelet activity in rabbit and rat blood and reverses the increase in platelet aggregation in response to oxidant stress.

Parkinson's disease (PD) is a neurodegenerative disorder characterized by non-motor and motor disabilities. This study investigated whether succinobucol (SUC) could mitigate nigrostriatal injury caused by intranasal 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) administration in mice. Moreover, the effects of SUC against MPTP-induced behavioral impairments and neurochemical changes were also evaluated. The quantification of tyrosine hydroxylase-positive (TH + ) cells was also performed in primary mesencephalic cultures to evaluate the effects of SUC against 1-methyl-4-phenylpyridinium (MPP + ) toxicity in vitro. C57BL/6 mice were treated with SUC (10 mg/kg/day, intragastric (i.g.)) for 30 days, and thereafter, animals received MPTP infusion (1 mg/nostril) and SUC treatment continued for additional 15 days. MPTP-infused animals displayed significant non-motor symptoms including olfactory and short-term memory deficits evaluated in the olfactory discrimination, social recognition, and water maze tasks. These behavioral impairments were accompanied by inhibition of mitochondrial NADH dehydrogenase activity (complex I), as well as significant decrease of TH and dopamine transporter (DAT) immunoreactivity in the substantia nigra pars compacta and striatum. Although SUC treatment did not rescue NADH dehydrogenase activity inhibition, it was able to blunt MPTP-induced behavioral impairments and prevented the decrease in TH and DAT immunoreactivities in substantia nigra (SN) and striatum. SUC also suppressed striatal astroglial activation and increased interleukin-6 levels in MPTP-intoxicated mice. Furthermore, SUC significantly prevented the loss of TH + neurons induced by MPP + in primary mesencephalic cultures. These results provide new evidence that SUC treatment counteracts early non-motor symptoms and neurodegeneration/neuroinflammation in the nigrostriatal pathway induced by intranasal MPTP administration in mice by modulating events downstream to the mitochondrial NADH dehydrogenase inhibition.

Bradykinesia and hypokinesia represent well-known motor symptoms of Parkinson's disease (PD). While bradykinesia (slow execution of movements) is present in less affected PD patients and aggravates as the disease severity increases, hypokinesia (reduction of movement) seems to emerge prominently only in the more affected patients. Here we developed a model based on the central infusion of low dose (40μg) 6-hydroxydopamine (6-OHDA) in mice in an attempt to discriminate bradykinesia (accessed through forelimb inability) from hypokinesia (accessed through locomotor and exploratory activities). The potential beneficial effects of succinobucol against 6-OHDA-induced forelimb inability were also evaluated. One week after the beginning of treatment with succinobucol (i.p. injections, 10mg/kg/day), mice received a single i.c.v. infusion of 6-OHDA (40μg/site). One week after 6-OHDA infusion, general locomotor/exploratory activities (open field test), muscle strength (grid test), forelimb skill (single pellet task), as well as striatal biochemical parameters related to oxidative stress and cellular homeostasis (glutathione peroxidase, glutathione reductase and NADH dehydrogenases activities, lipid peroxidation and TH levels), were evaluated. 6-OHDA infusions did not change locomotor/exploratory activities and muscle strength, as well as the evaluated striatal biochemical parameters. However, 6-OHDA infusions caused significant reductions (50%) in the single pellet reaching task performance, which detects forelimb skill inability and can be used to experimentally identify bradykinesia. Succinobucol partially protected against 6-OHDA-induced forelimb inability. The decreased forelimb ability with no changes in locomotor/exploratory behavior indicates that our 6-OHDA-based protocol represents a useful tool to mechanistically study the dissociation of bradykinesia and hypokinesia in PD., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Succinobucol (succinyl ester of probucol) is a lipid-lowering compound with anti-inflammatory and antioxidant properties. Recent experimental evidence has highlighted the potential neuroprotective effects of succinobucol. In the present study, cultured neuroblastoma (SH-SY5Y) cells were used to investigate mechanisms mediating the potential protective effect of succinobucol against mitochondrial metabolic impairment and oxidative stress induced by 3-nitropropionic acid (3-NP), a succinate dehydrogenase inhibitor that has been used in experimental models of the Huntington disease (HD). 3-NP decreased cellular viability after 24 h of incubation. This decline in cellular viability was preceded by (i) reduced mitochondrial complex II activity, (ii) increased reactive species generation, (iii) decreased mitochondrial membrane potential (ΔΨm), and (iv) diminished glutathione (GSH) levels. Succinobucol pretreatment (6 days) significantly prevented 3-NP-induced loss of cellular viability, generation of reactive oxygen species, and decrease of ΔΨm. However, succinobucol pretreatment did not protect against 3-NP-induced inhibition of mitochondrial complex II activity, pointing to the mitigation of secondary events resultant from mitochondrial complex II inhibition. Succinobucol pretreatment (6 days) significantly increased (50 %) the levels of GSH in SH-SY5Y cells, and this event was paralleled by significant increases in glutamate cysteine ligase messenger RNA (mRNA) expression and activity (GCL; the first enzyme in the GSH biosynthesis). The present findings are the first to show that succinobucol increases GSH levels via upregulation of GCL activity (possibly through the activation of the nuclear (erythroid-derived 2)-related factor (Nrf2)/antioxidant response element (ARE) pathway), displaying protective effects against mitochondrial dysfunction-derived oxidative stress.

Cancer metastasis is the main cause for the high mortality in breast cancer patients. Herein, we first report succinobucol-loaded pH-responsive wormlike micelles (PWMs) with sequential targeting capability to inhibit lung metastasis of breast cancer. PWMs can in a first step be delivered specifically to the sites of metastases in the lungs and then enable the intracellular pH-stimulus responsive drug release in cancer cells to improve the anti-metastatic effect. PWMs are identified as nanofibrillar assemblies with a diameter of 19.9 ± 1.9 nm and a length within the 50-200 nm range, and exhibited pH-sensitive drug release behavior in response to acidic intracellular environments. Moreover, PWMs can obviously inhibit the migration and invasion abilities of metastatic 4T1 breast cancer cells, and reduce the expression of the metastasis-associated vascular cell adhesion molecule-1 (VCAM-1) at 400 ng mL(-1) of succinobucol. In particular, PWMs can induce a higher specific accumulation in lung and be specifically delivered to the sites of metastases in lung, thereby leading to an 86.6% inhibition on lung metastasis of breast cancer. Therefore, the use of sequentially targeting PWMs can become an encouraging strategy for specific targeting and effective treatment of cancer metastasis., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Cancer metastasis is the leading reason for the high mortality of breast cancer. Herein, we report on a pH-responsive host-guest nanosystem of succinobucol (PHN) with pH-stimuli controlled drug release behavior to improve the therapeutic efficacy on lung metastasis of breast cancer. PHN was composed of the host polymer of β-cyclodextrin linked with multiple arms of N,N-diisopropylethylenediamine (βCD-DPA), the guest polymer of adamantyl end-capped methoxy poly(ethylene glycol) (mPEG-Ad), and the active agent of succinobucol. PHN comprises nanometer-sized homogenous spherical particles, and exhibits specific and rapid drug release in response to the intracellular acidic pH-stimuli. Then, the anti-metastatic efficacy of PHN is measured in metastatic 4T1 breast cancer cells, which effectively confirms the superior inhibitory effects on cell migration and invasion activities, VCAM-1 expression and cell-cell binding of RAW 264.7 to 4T1 cells. Moreover, PHN can be specifically delivered to the sites of metastatic nodules in lungs, and result in an obviously improved therapeutic efficacy on lung metastasis of breast cancer. Thereby, the pH-responsive host-guest nanosystem can be a promising drug delivery platform for effective treatment of cancer metastasis.

The prevention and treatment of lung metastasis of breast cancer remain a major challenge. The vascular cell adhesion molecule-1 (VCAM-1) could provide a potential therapeutic target in lung metastasis. Herein, succinobucol (SCB), a water-insoluble potent and selective VCAM-1 inhibitor, was assembled with triblock polymer poloxamer P188 into nanoparticles due to the intermolecular hydrophobic interactions. The experimental results showed that the SCB loaded nanoparticles (SN) could greatly improve the oral delivery and suppress the lung metastasis of breast cancer. The cell migration and invasion abilities of metastatic 4T1 breast cancer cells were obviously inhibited by SN. Moreover, the VCAM-1 expression on 4T1 cells was significantly reduced by SN, and the cell-cell binding ratio of RAW 264.7 cells to 4T1 cells greatly decreased from 47.4% to 3.2%. Furthermore, the oral bioavailability of SCB was greatly improved about 13-fold by SN, and the biodistribution in major organs was evidently enhanced. In particular, in the metastatic breast cancer model, the lung metastasis was notably reduced by SN treatment, and the VCAM-1 expression in lung tissues was significantly inhibited. Thereby, SN could evoke a new effective therapeutic efficacy of SCB on lung metastasis of breast cancer by inhibition of VCAM-1 expression., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Feeding intolerance resulting from delayed gastric emptying is common in premature neonates. Metoclopramide (MCP), the most frequently used prokinetic drug in neonates, enhances gastric muscle contractility through inhibition of dopamine receptors. Although its therapeutic benefit is established in adults, limited data are available to support its clinical use in infants. Hypothesizing that developmentally dependent differences are present, we comparatively evaluated the effect of MCP on fundus muscle contractility in newborn, juvenile, and adult rats. The muscle strips were either contracted with electrical field stimulation (EFS) to induce cholinergic nerve-mediated acetylcholine release or carbachol, a cholinergic agonist acting directly on the muscarinic receptor. Although in adult rats MCP increased EFS-induced contraction by 294 ± 122% of control (P < 0.01), no significant effect was observed in newborn fundic muscle. MCP had no effect on the magnitude of the carbachol-induced and/or bethanechol-induced gastric muscle contraction at any age. In response to dopamine, an 80.7 ± 5.3% relaxation of adult fundic muscle was observed, compared with only a 8.4 ± 8.7% response in newborn tissue (P < 0.01). Dopamine D2 receptor expression was scant in neonates and significantly increased in adult gastric tissue (P < 0.01). In conclusion, the lack of MCP effect on the newborn fundic muscle contraction potential relates to developmental differences in dopamine D2 receptor expression. To the extent that these novel data can be extrapolated to neonates, the therapeutic value of MCP as a prokinetic agent early in life requires further evaluation.

Nearly 285 million people worldwide, with 10% being Americans, suffer from diabetes mellitus and its associated comorbidities. This is projected to increase by 6.5% per year, with 439 million inflicted by year 2030. Both morbidity and mortality from diabetes stem from the consequences of microvascular and macrovascular complications. Of the 285 million with diabetes, over a quarter of a million die per year from related complications, making diabetes the fifth leading cause of death in high-income countries. These startling statistics illustrate the therapeutic failure of current diabetes drugs to retard the progression of diabetes. These statistics further illustrate the continual need for further research and development of alternative drugs with novel mechanisms to slow disease progression and disease complications. The treatment algorithm updated in 2008 by American Diabetes Association and the European Association for the Study of Diabetes currently recommends the traditional medications of metformin, either as monotherapy or in combination with sulfonylurea or insulin, as the preferred choice in the tier 1 option. The algorithm only suggests addition of alternative medications such as pioglitazone and incretin-based drugs as second-line agents in the tier 2 "less well-validated" option. However, these traditional medications have not proven to delay the progressive course of diabetes as evidence of increasing need over time for multiple drug therapy to maintain sufficient glycemic control. Because current diabetes medications have limited efficacy and untoward side effects, the development of diabetes mellitus drugs with newer mechanisms of action continues. This article will review the clinical data on the newly available incretin-based drugs on the market, including glucagon-like peptide agonists and of dipeptidyl peptidase type-4 inhibitors. It will also discuss 2 unique medications: pramlintide, which is indicated for both type and type-2 diabetes, and colesevelam, which is approved by the United States Food and Drug Administration for both type-2 diabetes and hyperlipidemia. It will further review the clinical data on the novel emerging agents of sodium-glucose cotransporter-2 inhibitors, tagatose, and succinobucol, all currently in phase III clinical trials. This review article can serve as an aid for clinicians to identify clinical indications in which these new agents can be applied in the treatment algorithm.

Oxidative stress, inflammation, and hyperlipidemia are common factors involved in the pathophysiology of atherosclerosis and type 2 diabetes. We have previously developed multifunctional antidyslipidemic derivatives with antioxidant and antiatherogenic properties. We now report the design, synthesis, and evaluation of two such novel derivatives that incorporate a structural moiety of the antidiabetic agent succinobucol. The new compounds exhibited a much improved in vitro antioxidant and squalene synthase inhibitory activity (at lower micromolar concentrations) as well as a significant antihyperlipidemic effect, reducing plasma total cholesterol, triglycerides, and MDA by 65-90%. Compound 2 also indicated a good anti-inflammatory activity, decreasing edema by 44%, while it was further evaluated for its antidiabetic activity using a type 2 diabetes experimental mouse model. After 7 weeks of administration, it produced a significant antihyperglycemic and antihyperlipidemic activity. In conclusion, rational drug design led to a compound combining improved antioxidant, antidyslipidemic, and antidiabetic action that may serve as a potential therapeutic strategy in metabolic syndrome disorders.

Objective: The aim of this study was to assess the efficacy of stent-based delivery of succinobucol alone and in combination with rapamycin in a porcine coronary model., Background: Current drugs and polymers used to coat coronary stents remain suboptimal in terms of long term efficacy and safety. Succinobucol is a novel derivative of probucol with improved antioxidant and anti-inflammatory properties., Methods: Polymer-free Yukon stents were coated with 1% succinobucol (SucES), 2% rapamycin (RES), or 1% succinobucol plus 2% rapamycin solutions (SucRES) and compared with a bare metal stent (BMS)., Results: The in vivo release profile of SucES indicated drug release up to 28 days (60% drug released at 7 days); 41 stents (BMS, n = 11; SucES, n =10; RES, n = 10; SucRES, n = 10) were implanted in the coronary arteries of 17 pigs. After 28 days, mean neointimal thickness was 0.31 ± 0.14 mm for BMS, 0.51 ± 0.14 mm for SucES, 0.19 ± 0.11 mm for RES, and 0.36 ± 0.17 mm for SucRES (P < 0.05 for SucES vs. BMS). SucES increased inflammation and fibrin deposition compared with BMS (P < 0.05), whereas RES reduced inflammation compared with BMS (P < 0.05)., Conclusion: In this model, stent-based delivery of 1% succinobucol using a polymer-free stent platform increased neointimal formation and inflammation following coronary stenting., (Copyright © 2012 Wiley Periodicals, Inc.)

This study evaluated and compared the potential protective effects of probucol and succinobucol, two lipid-lowering compounds with anti-inflammatory and antioxidant properties, on oxidative stress and mitochondrial dysfunction induced by 3-nitropropionic acid (3-NP, a succinate dehydrogenase (SDH) inhibitor largely used as model of Huntington's disease) in rat brain mitochondria-enriched synaptosomes. 3-NP caused significant inhibition of mitochondrial complex II activity, induced mitochondrial dysfunction and oxidative stress. Probucol and succinobucol prevented oxidative stress, but only succinobucol was able to prevent the mitochondrial dysfunction induced by 3-NP. Succinobucol, which did not recover complex II inhibition, was able to protect against 3-NP-induced decreased of MTT reduction, indicating that SDH is not the only enzyme responsible for MTT reduction. The present findings suggest that succinobucol might be a novel strategy to slow or halt oxidative events in neurodegenerative conditions., (Copyright © 2013 Elsevier B.V. and Mitochondria Research Society. All rights reserved.)

When comparing two treatment groups in a time-to-event analysis, it is common to use a composite event consisting of two or more distinct outcomes. The goal of this paper is to develop a statistical methodology to derive efficiency guidelines for deciding whether to expand a study primary endpoint from E1 (for example, non-fatal myocardial infarction and cardiovascular death) to the composite of E1 and E2 (for example, non-fatal myocardial infarction, cardiovascular death or revascularisation). We investigate this problem by considering the asymptotic relative efficiency of a log-rank test for comparing treatment groups with respect to a primary relevant endpoint E1 versus the composite primary endpoint, say E, of E1 and E2, where E2 is some additional endpoint., (Copyright © 2012 John Wiley & Sons, Ltd.)

Four different polymorphs, A, C, D, and E, of succinobucol were isolated and characterized by means of solid-state nuclear magnetic resonance spectroscopy, single crystal and powder X-ray diffraction, differential scanning calorimetry, thermogravimetry, and attenuated total reflection-infrared spectroscopy. From a number of experiments, the same polymorphs (C, D, and E) and an equilibrium phase mixture B consisting of polymorphs C and D were repeatedly gained using different solvents or their mixtures. Although polymorph A was obtained directly from recrystallization only on few occasions, polymorphs C, D, and E proved to be metastable kinetic polymorphs, which slowly transform to a thermodynamically more stable form A during long-term storage. The single-crystal structures of polymorph C and D were determined by X-ray single-crystal diffraction., (Copyright © 2012 Wiley Periodicals, Inc.)

Probucol inhibits the proliferation of vascular smooth muscle cells in vitro and in vivo, and the drug reduces intimal hyperplasia and atherosclerosis in animals via induction of heme oxygenase-1 (HO-1). Because the succinyl ester of probucol, succinobucol, recently failed as an antiatherogenic drug in humans, we investigated its effects on smooth muscle cell proliferation. Succinobucol and probucol induced HO-1 and decreased cell proliferation in rat aortic smooth muscle cells. However, whereas inhibition of HO-1 reversed the antiproliferative effects of probucol, this was not observed with succinobucol. Instead, succinobucol but not probucol induced caspase activity and apoptosis, and it increased mitochondrial oxidation of hydroethidine to ethidium, suggestive of the participation of H(2)O(2) and cytochrome c. Also, succinobucol but not probucol converted cytochrome c into a peroxidase in the presence of H(2)O(2), and succinobucol-induced apoptosis was decreased in cells that lacked cytochrome c or a functional mitochondrial complex II. In addition, succinobucol increased apoptosis of vascular smooth muscle cells in vivo after balloon angioplasty-mediated vascular injury. Our results suggest that succinobucol induces apoptosis via a pathway involving mitochondrial complex II, H(2)O(2), and cytochrome c. These unexpected results are discussed in light of the failure of succinobucol as an antiatherogenic drug in humans., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Synthesis, detailed structural characterization (X-ray, NMR, MS, IR, elemental analysis), and studies of toxicity, antioxidant activity and bioavailability of unique potent anti-atherosclerotic succinobucol-steroid conjugates are reported. The conjugates consist of, on one side, the therapeutically important drug succinobucol ([4-{2,6-di-tert-butyl-4-[(1-{[3-tert-butyl-4-hydroxy-5-(propan-2-yl)phenyl]sulfanyl}ethyl)sulfanyl]phenoxy}-4-oxo-butanoic acid]) possessing an antioxidant and anti-inflammatory activity, and on the other side, plant stanol/sterols (stigmastanol, β-sitosterol and stigmasterol) possessing an ability to lower the blood cholesterol level. A cholesterol-succinobucol prodrug was also prepared in order to enhance the absorption of succinobucol through the intestinal membrane into the organism and to target the drug into the place of lipid metabolism-The enterohepatic circulation system. Their low toxicity towards mice fibroblasts at maximal concentrations, their antioxidant activity, comparable or even higher than that of ascorbic acid as determined by direct quenching of the DPPH radical, and their potential for significantly altering total and LDL cholesterol levels, suggest that these conjugates merit further studies in the treatment of cardiovascular or other related diseases. A brief discussion of succinobucol's ability to quench the radicals, supported with a computational model of the electrostatic potential mapped on the electron density surface of the drug, is also presented.

How to manage residual atherosclerosis risk after the statin therapy is a major concern in cardiovascular medicine. In addition to life-style modifications, new drugs against atherosclerotic and inflammatory vascular diseases are expected. In current clinical trials, phospholipase A2 inhibitors(darapladib, varespladib), RVX-208, D-4F, CETP inhibitors (anacetrapib, dalcetrapib), succinobucol are investigated. Some has been failed, but others are still promising. On molecular target basis of PAF-AH, CETP, PON, ABC transporters of A1 and G1, SR-BI, HO-1, potential benefits and side effects are discussed.

The antioxidant and anti-inflammatory compound AGI-1067 (succinobucol) has potential as an oral anti-diabetic agent. AGI-1067 reduces H(b)A1c, improves fasting plasma glucose, and reduces new-onset diabetes. We investigated AGI-1067 for possible effects on mouse pancreatic islets in vitro. Pretreatment with 10 microM AGI-1067 increased glucose-stimulated insulin secretion (11 mM) without affecting secretion in basal (3 mM) glucose. AGI-1067 enhanced the intracellular calcium response to glucose stimulation in 7 mM and 11 mM glucose, but had no effect in 28 mM or basal glucose. AGI-1067-pretreated islets also showed enhanced calcium responses to methyl pyruvate and alpha-ketoisocaproate at low doses, but not high doses. The AGI-1067-mediated effects on glucose-stimulated calcium were maintained during continuous diazoxide exposure, suggesting effects on the K(ATP)-channel-independent pathway. AGI-1067 also reduced cytokine-induced islet cell death and expression of iNOS, a key component in cytokine signaling. This is the first report of direct stimulatory and protective effects of a first-in-class potential anti-diabetic agent on pancreatic islets., (2010 Elsevier Ireland Ltd. All rights reserved.)

Cardiovascular diseases remain a major cause of morbidity and mortality worldwide, regardless of the recent advances in medical and surgical treatment, for as life expectancy in the developed countries increases, cardiovascular conditions affecting the elderly also rises. Atherosclerosis and cardiovascular diseases take a huge toll on the society, making them the leading cause of death in developed countries. Phenomenal advances in the pathophysiology of cardiovascular disease and the molecular signaling pathways has revealed the role of endothelial dysfunction involved therein and thus has raised the possibility of novel therapeutic targets. Such potential cellular targets include the vascular smooth muscle cells, monocyte/macrophage cell lines, platelets, and endothelial cells. Certain studies affirm that antiplatelet agents, antioxidant therapies, amino acid supplementation, angiotensin converting enzyme inhibitors, and angiotensin receptor blockers may prevent or slow the progression of the disease process. The race is on for new medicines that can treat and prevent heart attacks and strokes, arising out of atherosclerosis, which kills nearly 1 million people a year in the U.S.A alone.

Objective: Induction of heme oxygenase-1 (HO-1) protects against atherosclerotic disease in part by promoting reendothelialization. As endothelial progenitor cells (EPCs) contribute to reendothelialization, we examined the role of HO-1 on bone marrow and circulating EPCs., Methods and Results: In a rabbit model of aortic balloon injury, pharmacological induction of HO-1 enhanced reendothelialization at sites with and without adjacent blood vessels, the latter indicative of a contribution by EPCs. Coinciding with maximal HO-1 induction in the injured vessel, plasma concentrations of bilirubin and the numbers of circulating progenitor cells were elevated. Both processes were abolished by cotreatment of the animals with an inhibitor of HO-1. Inducers of HO-1 promoted bone marrow cells to form progenitor cell colonies, and Flk1(+)/Sca-1(+)-cells to adhere to the luminal surface of the injured vessel. In noninjured mice, HO-1 inducers also increased bone marrow and circulating EPCs, and the ability of these cells to differentiate and form colonies. Compared to wild-type mice, bone marrow cells from HO-1(-/-) mice generated fewer endothelial colony-forming cells, and HO-1 inducers failed to promote CFU-Hill colony formation., Conclusions: These findings suggest that HO-1 contributes to vascular repair by increasing circulating EPCs derived from the bone marrow.

Skeletal muscle function is dependent on its highly regular structure. In studies of dystrophic (dy/dy) mice, the proportion of malformed myofibers decreases after prolonged whole muscle stimulation, suggesting that the malformed myofibers are more prone to injury. The aim of this study was to assess morphology and to measure excitation-contraction (EC) coupling (Ca(2+) transients) and susceptibility to osmotic stress (Ca(2+) sparks) of enzymatically isolated muscle fibers of the extensor digitorum longus (EDL) and flexor digitorum brevis (FDB) muscles from young (2-3 mo) and old (8-9 mo) mdx and age-matched control mice (C57BL10). In young mdx EDL, 6% of the myofibers had visible malformations (i.e., interfiber splitting, branched ends, midfiber appendages). In contrast, 65% of myofibers in old mdx EDL contained visible malformations. In the mdx FDB, malformation occurred in only 5% of young myofibers and 11% of old myofibers. Age-matched control mice did not display the altered morphology of mdx muscles. The membrane-associated and cytoplasmic cytoskeletal structures appeared normal in the malformed mdx myofibers. In mdx FDBs with significantly branched ends, an assessment of global, electrically evoked Ca(2+) signals (indo-1PE-AM) revealed an EC coupling deficit in myofibers with significant branching. Interestingly, peak amplitude of electrically evoked Ca(2+) release in the branch of the bifurcated mdx myofiber was significantly decreased compared with the trunk of the same myofiber. No alteration in the basal myoplasmic Ca(2+) concentration (i.e., indo ratio) was seen in malformed vs. normal mdx myofibers. Finally, osmotic stress induced the occurrence of Ca(2+) sparks to a greater extent in the malformed portions of myofibers, which is consistent with deficits in EC coupling control. In summary, our data show that aging mdx myofibers develop morphological malformations. These malformations are not associated with gross disruptions in cytoskeletal or t-tubule structure; however, alterations in myofiber Ca(2+) signaling are evident.

Purpose of Review: New therapies for the management of cardiovascular disease remain highly desirable, yet the recently developed agents, such as the cholesterylester transfer protein inhibitor torcetrapib, the antidiabetic agent rosiglitazone, and anti-inflammatory inhibitors of cyclooxygenase-2, have failed. In this review, the more recent developments in the molecular mechanisms underlying the beneficial activities of probucol and related compounds are described., Recent Findings: In-vivo and in-vitro studies have revealed that several of the protective activities of probucol can be explained by the ability of this drug to induce the enzyme heme oxygenase-1. It is now apparent that the sulfur atoms, rather than the phenol moieties of probucol, are required for its antiatherogenic and antirestenotic activities. Compounds related to probucol that have improved efficacy without the adverse effects offer promise as novel therapies of cardiovascular disease. Recent results suggest these compounds may also be used for the prevention of type-2 diabetes, a disease that is increasing in prevalence and importance worldwide., Summary: The development of derivatives of probucol targeting anti-inflammatory and antioxidant processes, perhaps via induction of heme oxygenase-1, may add to the armamentarium of current agents used in treatment of atherosclerotic disease and diabetes.

Background: Oxidative stress play an important role triggering platelet/endothelial activation. AGI-1067 is a novel, phenolic antioxidant, and vascular protectant which dose-dependently inhibits PEA biomarkers in vitro. Whether treatment with AGI-1067 alters platelets in vivo is not known. We serially assessed release of established PEA biomarkers in subjects treated with AGI-1067 versus placebo in the frame of Assessment of Lipoprotein Profiles Randomized Trial (ALPS)., Methods: Healthy subjects (18-65 years) with multiple risk factors for coronary artery disease were randomized 1:1 to receive 300 mg AGI-1067 (n = 112) or matching placebo (n = 117) daily for 12 weeks. Anticoagulants, aspirin, NSAIDS, and COX inhibitors were not permitted in this study. Plasma samples were collected at baseline, and at week 12 after randomization. Platelet factor 4 (PF4), beta-thromboglobulin (betaTG), P-selectin, thromboxane (TxB2), and prostacyclin (6-keto-PGF1a) were measured by ELISA., Results: Treatment with AGI-1067 was associated with a highly significant reduction of TxB2 release (P < 0.0001) when compared to the placebo. There were no differences in PF4, betaTG, P-selectin, and 6-keto-PGF1a between and within groups. AGI-1067 also inhibits TxB2 release from calcium ionophore (A23187)-stimulated human platelets with the IC50 equals 1 microM; but does not interfere with 6-keto-PGF1alpha release in either A23187-, or TXA2-stimulated human aortic endothelial cells., Conclusion: AGI-1067 selectively reduces TxB(2 )production from stimulated platelets, and diminishes plasma TxB2 levels in ALPS participants. These data support earlier in vitro, and pilot ex vivo experiments suggesting antiplatelet properties of AGI-1067. Lack of 6-keto-PGF1a down regulation may represent an attractive advantage of AGI-1067 over currently available antiplatelet regimens.

Background: Succinobucol (AGI-1067) was developed as a probucol derivative with anti-inflammatory and antioxidant properties. It has undergone Phase III clinical trials to determine its place in the treatment of atherosclerotic disease., Objective: This paper reviews the available history, pharmacology and preclinical and clinical trial data of succinobucol., Methods: Data were compiled following review of publications indexed in Medline and International Pharmaceutical Abstracts, industry media releases and relevant bibliographies., Results/conclusion: In preclinical studies, succinobucol exhibited antioxidant, anti-inflammatory, antihyperglycemic and antiplatelet properties; however, these effects have not resulted in a reduction in cardiovascular clinical end points in clinical trials. Although proposed antihyperglycemic effects are being investigated, safety concerns and lack of clear cardiovascular benefit may limit its clinical use as an antihyperglycemic agent.

Background: Oxidative stress and inflammation are involved in the pathophysiology of atherosclerosis. Our aim was to assess the effects of the antioxidant succinobucol (AGI-1067) on cardiovascular outcomes in patients with recent acute coronary syndromes already managed with conventional treatments., Methods: After an acute coronary syndrome occurring 14-365 days before recruitment, 6144 patients were randomly assigned with a computer-generated randomisation list, stratified by study site, to receive succinobucol (n=3078) or placebo (n=3066) in addition to standard of care. Enrolment began in July, 2003; this event-driven trial was stopped in August, 2006, after the prespecified number of primary outcome events had occurred. The composite primary endpoint was time to first occurrence of cardiovascular death, resuscitated cardiac arrest, myocardial infarction, stroke, unstable angina, or coronary revascularisation. Efficacy analyses were done by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00066898., Findings: All randomised patients were included in the efficacy analyses. Succinobucol had no effect on the primary endpoint (530 events in succinobucol group vs 529 in placebo group; hazard ratio 1.00, 95% CI 0.89-1.13, p=0.96). The composite secondary endpoint of cardiovascular death, cardiac arrest, myocardial infarction, or stroke occurred in fewer patients in the succinobucol group than in the placebo group (207 vs 252 events; 0.81, 0.68-0.98, p=0.029). The tertiary endpoint of new-onset diabetes developed in fewer patients without diabetes at baseline in the succinobucol group than in such patients in the placebo group (30 of 1923 vs 82 of 1950 patients; 0.37, 0.24-0.56, p<0.0001). New-onset atrial fibrillation occurred more often in the succinobucol group than in the placebo group (107 of 2818 vs 55 of 2787 patients; 1.87, 1.67-2.09, p=0.0002). Although the number of patients who reported any treatment emergent adverse event was much the same in the two groups, more patients in the succinobucol group than in the placebo group reported bleeding episodes or anaemia (32 vs 18 and 37 vs ten, respectively) as serious adverse events. Relative to treatment with placebo, succinobucol increased LDL cholesterol and systolic blood pressure, and decreased HDL cholesterol and glycated haemoglobin (p<0.0001 for all)., Interpretation: Although succinobucol had no effect on the primary endpoint, changes in the rates of other clinical outcomes-both beneficial and harmful-will need to be further assessed before succinobucol is used in patients with atherosclerosis or as an antidiabetic agent.

Background: The antioxidant AGI-1067 was shown to reduce experimental atherosclerosis. The present study originally intended to study restenosis as a primary endpoint but was subsequently modified to primarily investigate the effects of AGI-1067 on coronary atherosclerosis., Methods and Results: This placebo-controlled randomized trial assessed the effects of AGI-1067 280 mg qd started before percutaneous coronary intervention (PCI) and administered for 12 months after PCI on atherosclerosis progression as assessed by coronary intravascular ultrasound (IVUS). Among patients with IVUS examinations considered technically adequate both at baseline and follow-up upon central laboratory assessments (n=232), plaque volume was not significantly modified with placebo (least squares mean change: -0.4mm(3), P=0.85 versus baseline), but was significantly reduced by -4.0mm(3) at end of treatment in the AGI-1067 group (P=0.001 versus baseline, P=0.12 versus placebo). LDL-cholesterol varied by -9% and +4% in the placebo and AGI-1067 groups, respectively (P<0.05 between groups), and HDL-cholesterol was reduced by 1% with placebo and 14% with AGI-1067 (P<0.05 between groups). Plasma myeloperoxidase was reduced by 6% with AGI-1067 (P<0.05) but hs-CRP was not significantly different between groups., Conclusions: Atherosclerosis regression (-4.0mm(3)) was observed in patients treated with AGI-1067, although this was not significantly different from placebo. The anti-inflammatory effect of AGI-1067 is supported by reduced levels of myeloperoxidase.

Probucol is a diphenolic compound with anti-oxidant and anti-inflammatory properties that reduces atherosclerosis and restenosis. Unfortunately, adverse effects on blood lipoproteins and cardiac electrophysiology have curtailed its use as a drug. Compounds related to probucol that have improved efficacy without the adverse effects offer promise as novel therapies of cardiovascular disease. Recent results suggest that these compounds may be used for the prevention of type 2 diabetes, a disease that is increasing in prevalence and importance world-wide. In this review, the molecular mechanisms underlying the beneficial activities of probucol and related compounds are described.

The Clinical Trials described in this article were presented at the Hotline and Clinical Trial Update Sessions of the European Society of Cardiology Congress held in September 2007 in Vienna, Austria. The sessions chosen for this article represent the scope of interest of Cardiovascular Drugs and Therapy. The presentations should be considered preliminary, as further analyses could alter the final publication of the results of these studies. PROSPECT evaluated echocardiographic criteria for optimal selection of patients with moderate to severe heart failure who may benefit from cardiac resynchronisation therapy, however concluded that no single echocardiographic measure can be recommended. EVEREST found that tolvaptan, a vasopressin V(2) antagonist, resulted in early weight reduction and improvement of dyspnoea in patients with acute heart failure, but lacked long term improvement. In ARISE, the anti-oxidant succinobucal did not affect the primary outcome in high risk cardiovascular patients, but improved the combination of cardiovascular death, myocardial infarction and stroke, and diabetic control in diabetics. ALOFT showed that the addition of the renin inhibitor aliskiren to an ACE inhibitor or ARB and a beta-blocker leads to favourable effects on neurohormonal actions in heart failure. FINESSE markedly improved coronary patency before PCI with half-dose reteplase/abciximab in STEMI patients, however without significantly improving short-term outcome. The Prague-8 Study evaluated whether routine clopidogrel administered >6 h pre-angiography would be a safe way to achieve therapeutic drug levels in case a follow-up intervention would be considered immediately, but appeared not justified because of bleeding complications. CARESS in MI showed that high risk patients with evolving STEMI who undergo thrombolytic therapy should undergo PCI early after the thrombolysis. Finally, the ACUITY trial found that in moderate or high risk Non ST elevation ACS patients triaged to PCI, coronary artery bypass graft (CABG) surgery, or medical management, bivalirudin, with or without associated GPIIb/IIIa inhibitor therapy, resulted in a marked reduction of bleeding at 30 days whilst preserving the ischemic and mortality benefit at 1 year follow up.

Despite significant advances in technology and technique, coronary restenosis remains the primary limitation of percutaneous transluminal coronary angioplasty (PTCA). Among patients undergoing PTCA, between 20% and 50% of patients who do not receive a stent and 10%-30% of those who do receive a stent develop restenosis within 6 months of the procedure. Drug-eluting stents, which release high local concentrations of antiproliferative or immunosuppressive agents directly into the vessel wall at the site of the lesion, have dramatically reduced the incidence of restenosis in patients undergoing PTCA. However, even with drug-eluting stents, a significant percentage of higher-risk patients develop in-stent restenosis. These data suggest that a role remains for effective, well-tolerated systemic pharmacologic therapies to further reduce the rate of restenosis. To date, the majority of systemic agents tested for restenosis prevention have failed to show significant benefit. Only 2 agents, probucol and cilostazol, have consistently demonstrated efficacy in preventing restenosis. In addition, the investigational agent AGI-1067 has demonstrated promising efficacy in early clinical trials. Together with drug-eluting stents, these therapies may for the first time reduce the rate of restenosis to near zero, even in high-risk patients, such as individuals with diabetes mellitus.

Oxidation-sensitive signals play an important role in platelet activation. AGI-1067 is a novel, phenolic, intra- and extracellular antioxidant that inhibits the expression of a number of proinflammatory genes involved in atherosclerosis. AGI-1067 is the metabolically stable monosuccinic acid ester of probucol, and a potent phenolic antioxidant representing a novel class of orally bioavailable compounds termed vascular protectants. AGI-1067 exhibits antioxidant activity equipotent to probucol. In addition, animal studies have demonstrated dual pharmacological activities of AGI-1067: the ability to block the expression of oxidation-sensitive inflammatory genes including genes that code for vascular cell adhesion molecule-1 and monocyte chemotactic protein-1. Importantly, AGI-1067 also exhibits mild antiplatelet properties inhibiting surface expression of various key platelet receptors, the formation of platelet monocyte microparticles and PAR-1 thrombin receptors. AGI-1067 is currently being tested in the late trials, and if proven to improve clinical outcomes (ARISE trial), the drug will ultimately be used in patients with different manifestations of atherosclerosis and atherothrombosis.

The characterization of the follicular hierarchy and the expression of the mRNA for the inhibin/activin subunits was investigated in the follicles of 2 lines of turkey hens selected for over 40 generations for increased egg production (Egg line) or increased body weight (Growth line). The follicular hierarchies of 6 hens from the Egg and Growth lines were characterized in middle (45 wk of age) and late production (58 wk of age). Relative follicular weights for individual hierarchical follicles (>12 mm), pooled small yellow follicles (5 to 12 mm), and large white follicles (2 to 5 mm) were calculated. Total RNA was extracted for Northern blot analysis from individual granulosa cell layers of the F1 through F4 follicles, and from the combined granulosa and theca layers of small yellow follicles and large white follicles from an additional 6 hens from each genetic line. Egg line hens displayed a more distinct follicular size hierarchy than Growth line hens at 45 and 58 wk. Although total follicular weight relative to body size was greater at 45 and 58 wk of age for the Egg line hens than the Growth line hens, the total number of hierarchical follicles was greater in the Growth line hens at 45 and 58 wk of age. Expression of follistatin and the inhibin beta(B)-subunit was highest in nonhierarchical follicles, whereas the expression of the inhibin alpha- and beta(A)-subunits was highest in the hierarchical follicles. The inhibin alpha- and beta(A)-subunit mRNA expression pattern in the 4 largest follicles of the Growth line hens was not similar to the Egg line hens or characteristic of laying hens that have a high rate of egg production. The unusual inhibin subunit mRNA expression in the largest hierarchical follicles of the Growth line hens may account for their development of an abnormal follicular size hierarchy and for their poor egg production.

Atherosclerosis is now well recognised as a chronic inflammatory process which may ultimately lead to myocardial infarction, stroke and peripheral vascular disease. The role of inflammation in the pathogenesis of atherosclerosis has lead to interest in developing therapies that target vascular inflammation. Leucocytes play a key role during atherosclerotic plaque development. Activated vascular endothelium expresses vascular cell adhesion cell molecule-1 (VCAM-1), a member of the adhesion molecule superfamily, to which monocytes and lymphocytes can bind. These inflammatory cells can then move through the endothelium by diapedesis and release cytokines and enzymes, important components in the progression of the lesion. Researchers have demonstrated that the extent of atherosclerotic lesions is significantly reduced in animal models with decreased VCAM-1 expression. VCAM-1 has therefore been identified as a potential anti-inflammatory therapeutic target, the hypothesis being that reduced expression of VCAM-1 will slow the development of atherosclerosis. Succinobucol (AGI-1067), an anti-oxidant compound also capable of inhibiting VCAM-1 gene expression, is an example of such an agent and is currently being investigated in a phase III cardiovascular end-point trial due to report in 2007. If the results are positive, further investigations should derive to what extent blockade of VCAM-1 by succinobucol, rather than its other effects, accounts for the reduction in vascular events.

Oxidation-sensitive signals are important in platelet activation. The novel, phenolic, intracellular and extra-cellular antioxidant AGI-1067 inhibits the expression of a number of proinflammatory genes involved in atherosclerosis. The effect of AGI-1067 on human platelets was evaluated. Blood obtained from 20 aspirin-naïve volunteers with multiple risk factors for vascular disease was preincubated with escalating concentrations of AGI-1067 for the assessment of its ex vivo effects on platelet aggregation and expression of major surface receptors flow cytometry, evaluated by flow cytometry. AGI-1067 resulted in significant inhibition of a variety of activation-dependent platelet biomarkers in healthy volunteers, including adenosine diphosphate-induced platelet aggregation and decreased surface platelet expression of glycoprotein IIb/IIIa antigen, activity with PAC-1 antibody, and glycoprotein Ib (CD42b). The effect of AGI-1067 differs from other known antiplatelet agents, suggesting opportunities for therapeutic combination. These data need to be confirmed in subjects receiving orally dosed AGI-1067 to be clinically relevant.

Inflammation has a fundamental role in mediating all stages of atherosclerotic disease. The key role of oxidation in linking lipids and inflammation to atherosclerosis is compelling and is supported by experimental evidence. However, the relevance of the antioxidant hypothesis for the treatment of patients with atherosclerosis has not been definitively proven. Results of randomized trials with 'antioxidant' vitamins have been disappointing, and there are potentially important problems associated with their use, including their potential pro-oxidant effects. Probucol has reduced postpercutaneous coronary intervention (PCI)-restenosis and progression of carotid atherosclerosis in clinical trials. The antioxidant vascular protectant AGI-1067 has also been effective at preventing atherosclerosis in all tested animal models. The nonintervened reference coronary segments of the PCI vessel demonstrated improvements with AGI-1067 in the Canadian Antioxidant Restenosis Trial-1 (CART-1), evidence supportive of a clinical effect on slowing atherosclerosis progression. Two trials test the antioxidant/anti-inflammatory hypothesis with AGI-1067; CART-2 assesses its value for the reduction of both atherosclerosis progression and post-PCI restenosis, and Aggressive Reduction of Inflammation Stops Events (ARISE), which is evaluating its effects on hard cardiovascular outcomes.

Objective: To review the synthesis, pharmacology, clinical trials, and adverse effects of AGI-1067, a novel agent for preventing restenosis., Data Sources: Literature searches were conducted using MEDLINE (1966-July 2005) and International Pharmaceutical Abstracts (1970-July 2005) for English-language articles containing the search terms AGI-1067, AGI 1067, and probucol. In addition, bibliographies from relevant articles were reviewed for additional references., Study Selection and Data Extraction: All articles identified from data sources were reviewed for relevant information. Applicable information was included in this review., Data Synthesis: AGI-1067, a derivative of the lipid-lowering agent probucol, is the first of a new class of drugs termed vascular protectants. It has antioxidant and lipid-lowering effects. In addition, it inhibits inflammatory processes without resultant immunosuppression through its selective inhibition of vascular cell adhesion molecule-1 expression. AGI-1067 also exhibited anti-atherosclerotic effects in preclinical studies. Relatively short-term treatment with AGI-1067 showed positive results compared with probucol in preventing restenosis in patients undergoing percutaneous coronary intervention. AGI-1067 appears to be well tolerated and holds important advantages over probucol in that it has fewer adverse effects on high-density lipoprotein cholesterol and the QT interval., Conclusions: The favorable safety profile of AGI-1067 offers potential advantages over its precursor, probucol. Preclinical and clinical studies indicate that it possesses antioxidant, antiinflammatory, and lipid-lowering properties. Ongoing Phase II and III studies will determine AGI-1067's place in therapy for the prevention of restenosis and reduction in cardiovascular events in patients undergoing percutaneous intervention for coronary atherosclerosis.

The pathogenesis of chronic inflammatory diseases, including rheumatoid arthritis, is regulated, at least in part, by modulation of oxidation-reduction (redox) homeostasis and the expression of redox-sensitive inflammatory genes including adhesion molecules, chemokines, and cytokines. AGIX-4207 [2-[4-[[1-[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]thio]-1-methylethyl]thio]-2,6-bis(1,1-dimethylethyl)phenoxy]acetic acid] is a novel, orally active, phenolic antioxidant and anti-inflammatory compound with antirheumatic properties. To elucidate its anti-inflammatory mechanisms, we evaluated AGIX-4207 for a variety of cellular, biochemical, and molecular properties. AGIX-4207 exhibited potent antioxidant activity toward lipid peroxides in vitro and displayed enhanced cellular uptake relative to a structurally related drug, probucol. This resulted in potent inhibition of cellular levels of reactive oxygen species in multiple cell types. AGIX-4207 selectively inhibited tumor necrosis factor (TNF)-alpha-inducible levels of the redox-sensitive genes, vascular cell adhesion molecule-1 and monocyte chemoattractant protein-1, with less inhibition of E-selectin, and no effect on intracellular adhesion molecule-1 expression in endothelial cells. In addition, AGIX-4207 inhibited cytokine-induced levels of monocyte chemoattractant protein-1, interleukin (IL)-6, and IL-8 from endothelial cells and human fibroblast-like synoviocytes as well as lipopolysaccharide-induced release of TNF-alpha, IL-1beta, and IL-6 from human peripheral blood mononuclear cells. AGIX-4207 did not inhibit TNF-alpha-induced nuclear translocation of nuclear factor of the kappa-enhancer in B cells (NF-kappaB), suggesting that the mechanism of action is independent of this redox-sensitive transcription factor. Taken together, these results provide a mechanistic framework for understanding the anti-inflammatory and antirheumatic activity of AGIX-4207 and provide further support for the view that inhibition of redox-sensitive inflammatory gene expression is an attractive approach for the treatment of chronic inflammatory diseases.

Inflammation has a fundamental role in mediating all stages of atherosclerotic disease. The key role of oxidation in linking lipids and inflammation to atherosclerosis is compelling and supported by experimental evidence. However, the relevance of the antioxidant hypothesis for the treatment of patients with atherosclerosis has not been definitively proven. Probucol has reduced post-percutaneous coronary intervention (PCI) restenosis and progression of carotid atherosclerosis in clinical trials. The antioxidant/vascular protectant AGI-1067 has also been effective at preventing atherosclerosis in all tested animal models. The nonintervened reference coronary segments of the PCI vessel demonstrated improvements with AGI-1067 in the Canadian Antioxidant Restenosis Trial-1 (CART-1), evidence supportive of a clinical effect on slowing atherosclerosis progression. Results of randomized trials with the "antioxidant" vitamins have been disappointing, but there are potentially important problems associated with their use, including their potential pro-oxidant effects. Two important trials that test the antioxidant/anti-inflammatory hypothesis are ongoing with AGI-1067: CART-2, which assesses its value for the reduction of both atherosclerosis progression in non-PCI vessels and post-PCI restenosis; and Aggressive Reduction of Inflammation Stops Events (ARISE), which is evaluating the effects of AGI-1067 on hard cardiovascular outcomes.

According to the oxidative modification hypothesis, antioxidants that inhibit the oxidation of low-density lipoprotein (LDL) are expected to attenuate atherosclerosis, yet not all antioxidants that inhibit LDL oxidation in vitro inhibit disease in animal models of atherosclerosis. As with animal studies, a benefit with dietary supplements of antioxidants in general and vitamin E in particular was anticipated in humans, yet the overall outcome of large, randomized controlled studies has been disappointing. However, in recent years it has become clear that the role of vitamin E in LDL oxidation and the relationship between in vitro and in vivo inhibition of LDL oxidation are more complex than previously appreciated, and that oxidative events in addition to LDL oxidation in the extracellular space need to be considered in the context of an antioxidant as a therapeutic drug against atherosclerosis. This review focuses on some of these complexities, proposes a novel method to assess in vitro 'oxidizability' of lipoprotein lipids, and summarizes the present situation of development of antioxidant compounds as drugs against atherosclerosis and related cardiovascular disorders.

Fujisawa is committed to improving the outcomes of transplant patients worldwide. Research and development programs are underway for a new modified release dosage form of tacrolimus (MR-4), a new analog of leflunomide (FK 778), and several novel compounds (PG 490-88, AGI 1096) in collaboration with other companies. These programs are targeted to address many of the unmet medical needs in transplantation including (1) improving compliance, (2) reducing chronic rejection, and (3) improving long-term safety by reducing infectious and cardiovascular risk.

Atherosclerosis is a disease of oxidative stress and inflammation. AGI-1067 [butanedioic acid, mono[4-[[1-[[3,5-bis(1,1-dimethylethyl)-4-,hydroxyphenyl]thio]-1-methylethyl]thio]-2,6-bis (1,1-dimethylethyl)phenyl] ester] is a metabolically stable derivative of, yet pharmacologically distinct from, the antioxidant drug probucol. It is a member of a novel class of orally active, antioxidant, anti-inflammatory compounds termed vascular protectants and exhibits antiatherosclerotic properties in multiple animal models and in humans. To elucidate its antiatherosclerotic mechanisms, we have evaluated several cellular and molecular properties of AGI-1067 in vitro. AGI-1067 exhibited potent lipid peroxide antioxidant activity comparable with probucol yet demonstrated significantly enhanced cellular uptake over that observed with probucol. AGI-1067, but not probucol, inhibited basal levels of reactive oxygen species (ROS) in cultured primary human endothelial cells and both basal and hydrogen peroxide-induced levels of ROS in the promonocytic cell line, U937. Furthermore, AGI-1067 inhibited the inducible expression of the redox-sensitive genes, vascular cell adhesion molecule-1 (VCAM-1) and monocyte chemoattractant protein-1, in endothelial cells as well as tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1beta, and IL-6 production in peripheral blood mononuclear cells, whereas probucol had no effect. cDNA array hybridization experiments demonstrated that AGI-1067 selectively inhibited the expression of only a subset of TNF-alpha-responsive and nuclear factor-kappaB (NF-kappaB)-inducible genes in endothelial cells. The inhibitory effect of AGI-1067 on inducible VCAM-1 gene expression occurred at the transcriptional level, yet AGI-1067 had no effect on the activation of the redox-sensitive transcription factor NF-kappaB. These studies suggest that the anti-inflammatory and antiatherosclerotic properties of AGI-1067 may be due to selective inhibition of redox-sensitive endothelial and monocyte inflammatory gene expression. These studies provide a molecular basis for understanding the mechanism of action of this new class of therapeutic antiatherosclerotic compounds.

Purpose of Review: In this article, the authors intend to provide an update on clinical trials of pharmacologic prevention of restenosis after percutaneous coronary interventions, placed in the perspective of the use of orally administered therapy for the prevention of atherosclerosis progression and clinical events., Recent Findings: AGI-1067, the mono-succinic acid ester of probucol, is a phenolic antioxidant member of a novel class of agents termed v-protectants. It has strong antioxidant properties equipotent to those of probucol and antiinflammatory properties. It inhibits gene expression of VCAM-1 and MCP-1 and has been effective at preventing atherosclerosis in all tested animal models including the non-human primate. In the Canadian Antioxidant Restenosis Trial (CART) 1, AGI-1067 and probucol improved lumen dimensions at the site of percutaneous coronary intervention. AGI-1067 also improved luminal dimensions of non-intervened coronary reference segments in the Canadian Antioxidant Restenosis Trial, which suggests a direct antiatherosclerosis effect. Probucol reduced post-percutaneous coronary intervention restenosis and progression of carotid atherosclerosis in other clinical trials. Although statins reduce atherosclerotic events, they do not appear to have a significant effect on restenosis. The failure of folate therapy to protect against restenosis in the Folate After Coronary Intervention Trial (FACIT) occurred despite significant reductions in homocysteine levels., Summary: Prevention of both post-percutaneous coronary intervention restenosis and atherosclerosis progression with a pharmacologic agent such as AGI-1067 may be an attractive treatment paradigm. Two important trials that test the antioxidant/antiinflammatory hypothesis are ongoing with AGI-1067: the Canadian Atherosclerosis and Restenosis Trial 2, which assesses its value for the reduction of both atherosclerosis progression and post-percutaneous coronary interventions restenosis, and the Aggressive Reduction of Inflammation Stops Events (ARISE) trial which is evaluating its effects on cardiovascular events.

AGI-1067 is a derivative of probucol that is a promising new development for the treatment of restenosis and possibly atherosclerosis. In monkeys fed a high-fat diet for 1 year, AGI-1067 prevented the development of atherosclerosis. In these monkeys, AGI-1067 lowered plasma levels of low-density lipoprotein (LDL)-cholesterol and, in contrast to probucol, was capable of increasing high-density lipoprotein (HDL)-cholesterol levels. Although AGI1067 did not have marked lipid-lowering effects in two transgenic mouse models (the LDL-receptor-deficient and apolipoprotein-E-deficient models) fed a high-fat chow, it decreased the atherosclerotic lesion area in the aorta. In a mouse model of acute inflammation, the mRNA for the pro-inflammatory vascular cell adhesion molecule-1 and monocyte chemoattractant protein-1 was upregulated and this was inhibited by AGI-1067. AGI-1067 inhibited the TNF-alpha induction of redox-sensitive inflammatory proteins, vascular cell adhesion molecule-1, monocyte chemoattractant protein-1 and Eselectin, in cell culture. In addition, AGI-1067 is an antioxidant. In the Canadian Antioxidant Restenosis Trial (CART-1) of AGI-1067 in percutaneous coronary interventions, AGI-1067 had no effect on LDL-cholesterol but lowered HDL-cholesterol. At 6 months follow up, the lumen area of the percutaneous coronary interventions segments was greater in patients treated with AGI1067 than in untreated patients. Restenosis rates were 37.5% in the placebo group and 26% in the AGI-1067 group. The lumen area of reference segments was reduced in the placebo group but increased with the higher doses of AGI1067. Unlike probucol, AGI-1067 did not alter QTc interval.

AGI-1067, the monosuccinic acid ester of probucol, is a phenolic antioxidant member of a novel class of agents termed vascular protectants. It has strong antioxidant properties, equipotent to those of probucol, and anti-inflammatory properties. It inhibits gene expression of vascular cell adhesion molecule-1 and monocyte chemotactic protein-1 and has been effective at preventing atherosclerosis in all tested animal models. It also improved luminal dimensions of reference segments in the percutaneous coronary intervention (PCI) vessels in the CART-1 clinical trial, which suggests a direct anti-atherosclerosis effect. Two important trials that test the antioxidant/anti-inflammatory hypothesis are ongoing with AGI-1067: the Canadian Atherosclerosis and Restenosis Trial, which assesses its value for the reduction of both atherosclerosis progression in non-PCI vessels and post-PCI restenosis, and the Aggressive Reduction of Inflammation Stops Events trial, which is evaluating the effects of AGI-1067 on hard cardiovascular outcomes.