Synergistic efficacy of concurrent treatment with cilostazol and probucol on the suppression of reactive oxygen species and inflammatory markers in cultured human coronary artery endothelial cells

Antioxidants inhibit advanced glycosylation end-product-induced apoptosis by downregulation of miR-223 in human adipose tissue-derived stem cells

Advanced glycosylation end products (AGEs) are endogenous inflammatory mediators that induce apoptosis of mesenchymal stem cells. A potential mechanism includes increased generation of reactive oxygen species (ROS). MicroRNA-223 (miR-223) is implicated in the regulation of cell growth and apoptosis in several cell types. Here, we tested the hypothesis that antioxidants N-acetylcysteine (NAC) and ascorbic acid 2-phosphate (AAP) inhibit AGE-induced apoptosis via a microRNA-dependent mechanism in human adipose tissue-derived stem cells (ADSCs). Results showed that AGE-HSA enhanced apoptosis and caspase-3 activity in ADSCs. AGE-HSA also increased ROS generation and upregulated the expression of miR-223. Interestingly, reductions in ROS generation and apoptosis, and upregulation of miR-223 were found in ADSCs treated with antioxidants NAC and AAP. Furthermore, miR-223 mimics blocked antioxidant inhibition of AGE-induced apoptosis and ROS generation. Knockdown of miR-223 amplified the protective effects of antioxidants on apoptosis induced by AGE-HSA. miR-223 acted by targeting fibroblast growth factor receptor 2. These results indicate that NAC and AAP suppress AGE-HSA-induced apoptosis of ADSCs, possibly through downregulation of miR-223.

Rationale and design of the PreventIon of CArdiovascular events in iSchemic Stroke patients with high risk of cerebral hemOrrhage (PICASSO) study: A randomized controlled trial

RATIONALE

Prior intracerebral haemorrhage and cerebral microbleeds may increase the risk of haemorrhagic stroke. However, the optimal long-term antiplatelet therapy and lipid management in these patients remain unclear.

AIM

PreventIon of CArdiovascular events in iSchemic Stroke patients with high risk of cerebral hemOrrhage was designed to compare cilostazol and aspirin and to assess the effect of adding probucol, a lipid-lowering and anti-oxidative agent, in patients at high risk of haemorrhagic stroke.

SAMPLE SIZE ESTIMATE

The projected sample size is 1600 patients with at least 12 months of follow-up.

METHODS AND DESIGN

PreventIon of CArdiovascular events in iSchemic Stroke patients with high risk of cerebral hemOrrhage is a randomized trial involving 67 institutes from 3 countries. Patients with non-cardioembolic ischemic stroke or transient ischemic attack within 180 days and with prior intracerebral haemorrhage or multiple cerebral microbleeds on gradient echo imaging are eligible. Enrolled patients are simultaneously randomized in a 2 × 2 factorial design: double-blind for cilostazol 200 mg/day vs. aspirin 100 mg/day, and an open-label, blind end-point evaluation for probucol 500 mg/day vs. non-probucol.

STUDY OUTCOMES

The co-primary end-points are the safety end-point of haemorrhagic stroke and the efficacy end-point of a composite of stroke, myocardial infarction, or vascular death. Time-to-event will be analyzed separately for each intervention: superiority testing for the safety of cilostazol over aspirin as well as the efficacy of probucol over non-probucol, and non-inferiority testing for the efficacy of cilostazol to aspirin.

DISCUSSION

PreventIon of CArdiovascular events in iSchemic Stroke patients with high risk of cerebral hemOrrhage is the largest secondary stroke prevention trial for informing antiplatelet therapy and lipid management in patients at high risk of haemorrhagic stroke.

Probucol plus cilostazol attenuate hypercholesterolemia‑induced exacerbation in ischemic brain injury via anti-inflammatory effects

Probucol, a lipid-lowering agent with anti-oxidant properties, is involved in protection against atherosclerosis, while cilostazol, an antiplatelet agent, has diverse neuroprotective properties. In this study, we investigated the anti-inflammatory effects of probucol and cilostazol on focal cerebral ischemia with hypercholesterolemia. Apolipoprotein E (ApoE) knockout (KO) mice were fed a high-fat diet (HFD) with or without 0.3% probucol and/or 0.2% cilostazol for 10 weeks. To assess the protective effects of the combined therapy of probucol and cilostazol on ischemic injury, the mice received 40 min of middle cerebral artery occlusion (MCAO). Infarct volumes, neurobehavioral deficits and neuroinflammatory mediators were subsequently evaluated 48 h after reperfusion. Probucol alone and probucol plus cilostazol significantly decreased total- and low-density lipoprotein (LDL)-cholesterol in ApoE KO with HFD. MCAO resulted in significantly larger infarct volumes in ApoE KO mice provided with HFD compared to those fed a regular diet, although these volumes were significantly reduced in the probucol plus cilostazol group. Consistent with a smaller infarct size, probucol alone and the combined treatment of probucol and cilostazol improved neurological and motor function. In addition, probucol alone and probucol plus cilostazol decreased MCP-1 expression and CD11b and GFAP immunoreactivity in the ischemic cortex. These findings suggested that the inhibitory effects of probucol plus cilostazol in MCP-1 expression in the ischemic brain with hypercholesterolemia allowed the identification of one of the mechanisms responsible for anti-inflammatory action. Probucol plus cilostazol may therefore serve as a therapeutic strategy for reducing the impact of stroke in hypercholesterolemic subjects.

Combined therapeutic effect of probucol and cilostazol on endothelial function in patients with silent cerebral lacunar infarcts and hypercholesterolemia: a preliminary study

OBJECTIVE

This study evaluated the efficacy of combined therapy with probucol and cilostazol on endothelial function in silent lacunar cerebral infarcts (SLCI) and mild hypercholesterolemia.

SUBJECTS AND METHODS

Flow-mediated vasodilatation (FMD) and nitroglycerin-induced vasodilatation (NMD) were measured before and after 4 weeks of combined therapy with probucol (500 mg/day) and cilostazol (200 mg/day) in 34 patients with a mean age of 72 ± 7 years (range 57-80 years) with SLCI, mild hypercholesterolemia (low-density lipoprotein cholesterol >100 mg/dl) and impaired endothelial function (FMD <6%). Patients were randomly allocated to one of the following two treatment groups: (1) aspirin (100 mg/day) with behavioral modifications, such as diet and/or exercise therapy (A group or control group, n = 17), and (2) probucol and cilostazol treatment (PC group, n = 17), also with behavioral modifications.

RESULTS

Although the baseline FMD was not different between the two treatment arms (2.7 ± 1.5 vs. 2.6 ± 1.5%, n.s.), the posttreatment FMD was significantly improved in the PC group (from 2.7 ± 1.5 to 3.5 ± 1.7%, p < 0.05) but not in the A group (from 2.6 ± 1.5 to 2.9 ± 1.4%, n.s.). No differences were observed between baseline and posttreatment NMD in either group. The effects of treatments on lipid profiles were more profound in the PC group.

CONCLUSION

Combined treatment with probucol and cilostazol resulted in subacute improvement in FMD/endothelial function in patients with SLCI with mild hypercholesterolemia. This combination therapy has the potential to reduce the risk of cardiovascular events via improvements in endothelial function and lipid profiles.

A combination of cilostazol and Ginkgo biloba extract protects against cisplatin-induced Cochleo-vestibular dysfunction by inhibiting the mitochondrial apoptotic and ERK pathways

Cisplatin (cis-diammine-dichloroplatinum; CDDP) is an anticancer drug that induces significant hearing loss and balance dysfunction as side effects. Cilostazol (CS, 6-[4-(1-cyclohexyl-1H-tetrazol-5-yl) butoxy]-3, 4-dihydro-2-(1H)-quinolinone) has neuroprotective and antioxidant effects, whereas Ginkgo biloba extract (GbE) has preventive effects on CDDP-induced hearing loss in rats, and GbE enhances the antiatherogenic effect of CS by inhibiting the generation of reactive oxygen species (ROS). The purpose of this study was to investigate the effects of renexin (RXN), which contains GbE and CS, against CDDP-induced cochleo-vestibular dysfunction in rats and to elucidate the mechanism underlying the protective effects of RXN on auditory cells. Rats intraperitoneally injected with CDDP exhibited an increase in hearing threshold and vestibular dysfunction, which agreed with hair cell damage in the Organ of Corti and otoliths. However, these impairments were significantly prevented in a dose-dependent manner by pre- and co-treatment with RXN, and these preventive effects in RXN-treated rats were more prominent than those in GbE-treated rats. In a CDDP pharmacokinetic study, platinum concentration was very similar between CDDP-only treated and RXN+CDDP cotreated rats. RXN markedly attenuated CDDP-induced intracellular ROS and significantly reduced CDDP-activated expression of p-extracellular regulated kinase (ERK), BAX, cytochrome c, cleaved caspase-3 and cleaved poly (ADP-ribose) polymerase, but increased BCL-XL expression. These results show that RXN may have a synergistic effect by strongly protecting hearing and vestibular dysfunction induced by CDDP by inhibiting ROS production, mitochondrial pathways and the ERK pathway, without interfering with CDDP pharmacokinetics. Therefore, RXN could potentially be used to reduce CDDP-related hearing loss and dizziness.

A randomized, open-label, multicentre study to evaluate plasma atherosclerotic biomarkers in patients with type 2 diabetes mellitus and arteriosclerosis obliterans when treated with Probucol and Cilostazol

Objectives

To evaluate the plasma atherosclerotic biomarkers in patients with type 2 diabetes mellitus (T2DM) and arteriosclerosis obliteran (ASO) when treated with Probucol plus Cilostazol in combination and individually.

Methods

In this open-label study, patients aged 40–75 years were randomized to receive conventional therapy alone, or with Cilostazol 100 mg bid, or with Probucol 250 mg bid, or with both in combination. Endpoints included changes in plasma biomarker and safety at 12 weeks.

Results

Of the 200 randomized patients, 165 for per-protocol and 160 for the safety (QTc intervals) were set, respectively. Probucol significantly reduced total cholesterol (P < 0.001), low-density lipoprotein cholesterol (LDL-C), (P = 0.01), and high-density lipoprotein cholesterol (HDL-C) (P < 0.001) compared with conventional therapy. Cilostazol was effective in increasing HDL-C (P = 0.002) and reducing triglycerides levels (P < 0.01) compared with conventional therapy. A trend towards significance was observed for the difference between conventional therapy alone and Probucol plus Cilostazol group for the change in oxidized low-density lipoprotein (Ox-LDL, P = 0.065). No significant effects on the majority of the remaining biomarkers were found across the treatment groups.

Conclusions

We have confirmed that Ox-LDL could be a possible plasma atherosclerotic biomarker among the evaluated biomarkers, which reflected the synergetic effect of Cilostazol plus Probucol in patients with T2DM and ASO shown previously in preclinical studies.

Ginkgo biloba extract (GbE) enhances the anti-atherogenic effect of cilostazol by inhibiting ROS generation

In this study, the synergistic effect of 6-[4-(1-cyclohexyl- 1H-tetrazol-5-yl) butoxy]-3,4-dihydro-2(1H )-quinolinone (cilostazol) and Ginkgo biloba extract (GbE) was examined in apolipoprotein E (ApoE) null mice. Co-treatment with GbE and cilostazol synergistically decreased reactive oxygen species (ROS) production in ApoE null mice fed a high-fat diet. Co-treatment resulted in a significantly decreased atherosclerotic lesion area compared to untreated ApoE mice. The inflammatory cytokines and adhesion molecules such as monocyte chemoattractant-1 (MCP-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), and VCAM-1 which can initiate atherosclerosis were significantly reduced by the co-treatment of cilostazol with GbE. Further, the infiltration of macrophages into the intima was decreased by co-treatment. These results suggest that co-treatment of GbE with cilostazol has a more potent anti-atherosclerotic effect than treatment with cilostazol alone in hyperlipidemic ApoE null mice and could be a valuable therapeutic strategy for the treatment of atherosclerosis.

Combinatorial effect of probucol and cilostazol in focal ischemic mice with hypercholesterolemia

Hypercholesterolemia may increase stroke risk by accelerating atherosclerosis, narrowing the luminal diameter in cerebral vessels, and disrupting both vascular endothelial and smooth muscle function. In the present study, we investigated the beneficial effects of combinatorial therapy with probucol and cilostazol on focal cerebral ischemia with hypercholesterolemia. Apolipoprotein E (ApoE) knockout (KO) mice were fed a high-fat diet with or without 0.5% probucol and/or 0.2% cilostazol for 10 weeks. Probucol alone and probucol and cilostazol significantly decreased total, low-density lipoprotein, and high-density lipoprotein cholesterol, whereas cilostazol did not affect the plasma cholesterol levels in ApoE KO mice. Administration of probucol alone and cilostazol alone significantly decreased atherosclerotic lesion area in the aorta, with a significant decrease evident using combinatorial administration. Middle cerebral artery occlusion resulted in significantly larger infarct volumes in ApoE KO mice fed 10 weeks of high-fat diet compared with those in ApoE KO mice fed a regular diet. The infarct volume was reduced significantly using probucol alone or cilostazol alone and even was reduced significantly by their combinatorial administration. Consistent with a larger infarct size, the combinatorial therapy prominently improved neurological function. The combinatorial administration increased cerebral blood flow during ischemia. Expression of endothelial nitric oxide synthase and adiponectin in the cortex were decreased by high-fat diet but were elevated by combinatorial treatment. Adiponectin expression colocalized within the cerebral vascular endothelium. The data suggest that the combination of probucol and cilostazol prevents cerebrovascular damage in focal cerebral ischemic mice with hypercholesterolemia by up-regulation of endothelial nitric oxide synthase and adiponectin.

Study design and rationale of "Synergistic effect of combination therapy with cilostazol and ProbUcol on plaque stabilization and lesion REgression (SECURE)" study: a double-blind randomised controlled multicenter clinical trial

Background

Probucol, a cholesterol-lowering agent that paradoxically also lowers high-density lipoprotein cholesterol has been shown to prevent progression of atherosclerosis. The antiplatelet agent cilostazol, which has diverse antiatherogenic properties, has also been shown to reduce restenosis in previous clinical trials. Recent experimental studies have suggested potential synergy between probucol and cilostazol in preventing atherosclerosis, possibly by suppressing inflammatory reactions and promoting cholesterol efflux.

Methods/design

The Synergistic Effect of combination therapy with Cilostazol and probUcol on plaque stabilization and lesion REgression (SECURE) study is designed as a double-blind, randomised, controlled, multicenter clinical trial to investigate the effect of cilostazol and probucol combination therapy on plaque volume and composition in comparison with cilostazol monotherapy using intravascular ultrasound and Virtual Histology. The primary end point is the change in the plaque volume of index intermediate lesions between baseline and 9-month follow-up. Secondary endpoints include change in plaque composition, neointimal growth after implantation of stents at percutaneous coronary intervention target lesions, and serum levels of lipid components and biomarkers related to atherosclerosis and inflammation. A total of 118 patients will be included in the study.

Discussion

The SECURE study will deliver important information on the effects of combination therapy on lipid composition and biomarkers related to atherosclerosis, thereby providing insight into the mechanisms underlying the prevention of atherosclerosis progression by cilostazol and probucol.

Trial registration number

ClinicalTrials (NCT): NCT01031667