Effect of cilostazol in treating diabetes-associated microvascular complications

Benefits of Cilostazol's Effect on Vascular and Neuropathic Complications Caused by Diabetes

Diabetes mellitus (DM) is a global health concern with a rising incidence, particularly in aging populations and those with a genetic predisposition. Over time, DM contributes to various complications, including nephropathy, retinopathy, peripheral arterial disease (PAD), and neuropathy. Among these, diabetic neuropathy and PAD stand out due to their high prevalence and significant impact on patients' quality of life. Diabetic distal symmetric polyneuropathy, the most common form of diabetic neuropathy, is driven by neuroinflammation stemming from prolonged hyperglycemia. Simultaneously, hyperglycemia significantly increases the risk of PAD, a condition further exacerbated by factors like smoking, age, and sedentary lifestyles. PAD frequently manifests as claudication, a debilitating symptom marked by pain and cramping during physical activity, which limits mobility and worsens patients' outcomes. Cilostazol, a phosphodiesterase-3 inhibitor, has proven effective in managing intermittent claudication in PAD by improving walking distances and enhancing blood flow. Recent studies have also explored its potential benefits for diabetic neuropathy. Cilostazol's mechanisms include vasodilation, platelet inhibition, and increased cyclic adenosine monophosphate (cAMP) levels, which may contribute to improved neurological outcomes. However, variability in the clinical evidence due to inconsistent treatment protocols highlights the need for further investigation. This review explores cilostazol's mechanisms of action and therapeutic applications for managing neuropathy and PAD in diabetic patients, aiming to provide insights into its potential as a dual-purpose pharmacological agent in this high-risk population.

Cilostazol for the treatment of distal symmetrical polyneuropathy in diabetes mellitus: Where do we stand?

INTRODUCTION

Diabetic Neuropathy (DN) is one of the most frequent chronic complications of diabetes mellitus. Its commonest form, distal symmetrical polyneuropathy (DSPN), is characterised by slowly progressing length-dependent nerve damage in the lower limbs, increasing the risk of foot ulcerations and leading to symptoms like tingling, pain, or numbness.

AIM

The aim of this review was to discuss the utility of cilostazol, a phosphodiesterase inhibitor with known antiplatelet, vasodilatory, anti-inflammation properties, in the treatment of DSPN.

RESULTS

Preclinical studies in animals have demonstrated the ability of cilostazol to improve nerve function and to protect from peripheral nerve disruption and central sensitisation. However, clinical trials in humans are very sparse and have so far not been encouraging.

CONCLUSIONS

Further research is needed to fully understand the mechanisms and potential efficacy of cilostazol in treating DSPN.

Cilostazol protects against gastric ulcers by regulating PPAR-γ, HO-1, PECAM-1, pErk-1, NF-κB, Bcl-2, and cleaved caspase-3 protein expression

Millions of individuals worldwide, across all age groups, suffer from the widespread health issue of gastric ulcers. In many experiments, cilostazol (Cls), a phosphodiesterase-3 inhibitor, was recently shown to have anti-ulcer activity. Notably, Cls increases the expression and transcriptional activity of PPAR-γ in vitro and in vivo. This study aimed to evaluate the protective effect of Cls against ethanol-induced gastric ulcers and clarify the possible underlying mechanisms with an emphasis on the role of PPAR-γ. Male albino rats were treated with ethanol to induce gastric ulcers, or they were pretreated with Cls, omeprazole (Omp), GW9662, or Cls + GW9662 for 14 consecutive days before receiving ethanol. Cls protects against ethanol-induced gastric ulcers. Cls treatment significantly reduced ethanol-induced upregulation of the pro-inflammatory markers (IL-1β, IL-6, TNF-α, and NF-κB), MDA (a marker of lipid peroxidation), and caspase-3 and cleaved caspase-3 (apoptotic markers). On the other hand, Cls treatment counteracted ethanol-induced downregulation of PPAR-γ, pErk-1, HO-1 and GSH (antioxidant markers), PECAM-1 and NO (healing markers), and Bcl-2 (antiapoptotic marker). However, when combined with GW9662, a potent antagonist of PPAR-γ, Cls loses its effects. In conclusion, these results suggest that PPAR-γ and pErk-1 are essential for Cls's protective effects against ethanol-induced gastric ulcers.

GLP-1: A Prospective Guardian for Comprehensive Myocardial Perfusion

OBJECTIVE

To investigate the role of glucagon-like peptide 1 (GLP-1) in myocardial perfusion, focusing on its effects on coronary microcirculation and cardiovascular outcomes.

METHODS

Review of foundational research and large-scale clinical trials, including Cardiovascular Outcome Trials (CVOTs), examining the cardiovascular effects of GLP-1. Systematic analysis of trial data to assess the impact of GLP-1 therapy on myocardial infarction, composite cardiovascular events, and stroke incidence.

RESULTS

GLP-1 therapy was found to significantly reduce myocardial infarction and composite cardiovascular events. Additionally, GLP-1 receptor agonists were observed to reduce stroke incidence, suggesting systemic effects on panvascular diseases. While direct protective effects on coronary microvasculature have been less studied, growing evidence supports GLP-1's role in comprehensive myocardial perfusion.

CONCLUSION

GLP-1 is a promising therapeutic agent for improving myocardial perfusion and reducing cardiovascular events. Its protection is likely associated with comprehensive improvements in myocardial perfusion, including effects on coronary microcirculation. Further research is needed to fully elucidate its mechanisms of action and potential clinical applications.

Pathogenesis, Assessment, and Treatment of Coronary Microcirculation Dysfunction

Cardiovascular disease is the predominant cause of mortality on a global scale. Research indicates that women exhibit a greater likelihood of presenting with non-obstructive coronary artery disease (CAD) when experiencing symptoms of myocardial ischemia in comparison to men. Additionally, women tend to experience a higher burden of symptoms relative to men, and despite the presence of ischemic heart disease, they are frequently reassured erroneously due to the absence of obstructive CAD. In cases of ischemic heart disease accompanied by symptoms of myocardial ischemia but lacking obstructive CAD, it is imperative to consider coronary microvascular dysfunction as a potential underlying cause. Coronary microvascular dysfunction, characterized by impaired coronary flow reserve resulting from functional and/or structural abnormalities in the microcirculation, is linked to adverse cardiovascular outcomes. Lifestyle modifications and the use of anti-atherosclerotic and anti-anginal medications may offer potential benefits, although further clinical trials are necessary to inform treatment strategies. This review aims to explore the prevalence, underlying mechanisms, diagnostic approaches, and therapeutic interventions for coronary microvascular dysfunction.

Cilostazol Ameliorates Motor Dysfunction and Schwann Cell Impairment in Streptozotocin-Induced Diabetic Rats

This study investigated the effects of cilostazol on motor dysfunction, spinal motor neuron abnormalities, and schwannopathy in rats with diabetes. Diabetes mellitus (DM) was induced in rats via femoral intravenous streptozotocin (STZ) injection (60 mg/kg). After successful DM induction, cilostazol was administered on day 15 via oral gavage (100 mg/kg/day) for 6 weeks until sacrifice. Behavioral assays, including motor function, were performed weekly. The sciatic nerve, L5 spinal cord, and spinal ventral root were collected to evaluate the expression of the glial fibrillary acidic protein (GFAP), myelin protein zero (P0), and choline acetyltransferase (ChAT) by immunofluorescence and Western blotting. DM rats displayed decreased running speeds, running distances, and toe spread but increased foot pressure. In addition, loss of non-myelinating Schwann cells and myelin sheaths was observed in the sciatic nerve and L5 spinal ventral root. Reduced numbers of motor neurons were also found in the L5 spinal ventral horn. Cilostazol administration significantly potentiated running speed and distance; increased hind paw toe spread; and decreased foot pressure. In the sciatic nerve and L5 spinal ventral root, cilostazol treatment significantly improved non-myelinated Schwann cells and increased myelin mass. ChAT expression in motor neurons in the spinal ventral horn was improved, but not significantly. Cilostazol administration may protect sensorimotor function in diabetic rats.

Chinese expert consensus on the diagnosis and treatment of coronary microvascular diseases (2023 Edition)

Since the four working groups of the Chinese Society of Cardiology issued first expert consensus on coronary microvascular diseases (CMVD) in 2017, international consensus documents on CMVD have increased rapidly. Although some of these documents made preliminary recommendations for the diagnosis and treatment of CMVD, they did not provide classification of recommendations and levels of evidence. In order to summarize recent progress in the field of CMVD, standardize the methods and procedures of diagnosis and treatment, and identify the scientific questions for future research, the four working groups of the Chinese Society of Cardiology updated the 2017 version of the Chinese expert consensus on CMVD and adopted a series of measures to ensure the quality of this document. The current consensus has raised a new classification of CMVD, summarized new epidemiological findings for different types of CMVD, analyzed key pathological and molecular mechanisms, evaluated classical and novel diagnostic technologies, recommended diagnostic pathways and criteria, and therapeutic strategies and medications, for patients with CMVD. In view of the current progress and knowledge gaps of CMVD, future directions were proposed. It is hoped that this expert consensus will further expedite the research progress of CMVD in both basic and clinical scenarios.

Real-World Safety and Effectiveness of Controlled-Release Cilostazol in Patients with Symptomatic Peripheral Artery Disease

BACKGROUND

Cilostazol is the only first-line medication for treating intermittent claudication, and the controlled-release (CR) formulation is associated with a lower prevalence of adverse events (AEs).

OBJECTIVE

The objective of the study was to assess the safety and effectiveness of cilostazol CR in patients with symptomatic peripheral artery disease (PAD).

METHODS

In this multicentre (113 sites), open-label, prospective observational study, we evaluated the real-world safety and effectiveness of cilostazol CR 200 mg once daily in patients with symptomatic PAD treated in routine clinical settings. The primary endpoint was the incidence and severity of AEs, and their causal relationship with cilostazol CR. The secondary endpoint was the effectiveness of the drug, as assessed by each patient's physician, for improving intermittent claudication.

RESULTS

Among 2063 participants who received cilostazol CR for a mean duration of 88.6 days, 99 (4.80 %) experienced adverse drug reactions (ADRs), although no unexpected adverse reactions were observed. There was no significant difference in the incidence of ADRs according to patient demographics and comorbidities (all p > 0.05). The treatment was 'effective' in 1600 patients (78.93 %), although effectiveness significantly differed according to the patients' sex and the presence of comorbidities, including diabetes mellitus, hypertension, and coronary artery disease (all p < 0.01).

CONCLUSIONS

This study demonstrated the tolerability and effectiveness of cilostazol CR treatment in patients with symptomatic PAD.

Mechanistic Protective Effect of Cilostazol in Cisplatin-Induced Testicular Damage via Regulation of Oxidative Stress and TNF-α/NF-κB/Caspase-3 Pathways

Despite being a potent anticancer drug, cisplatin has limited applicability due to its adverse effects, such as testicular damage. Consequently, reducing its toxicity becomes necessary. In this study, a selective phosphodiesterase-3 inhibitor, cilostazol, which is used to treat intermittent claudication, was examined for its ability to abrogate cisplatin-induced testicular toxicity. Its ameliorative effect was compared to that of two phosphodiesterase inhibitors, tadalafil and pentoxifylline. The study also focused on the possible mechanisms involved in the proposed protective effect. Cisplatin-treated rats showed a significant decrease in sperm number and motility, serum testosterone, and testicular glutathione levels, as well as a significant elevation in malondialdehyde, total nitrite levels, and the protein expression of tumor necrosis factor-alpha, nuclear factor-kappa β, and caspase-3. These outcomes were confirmed by marked testicular architecture deterioration. Contrary to this, cilostazol, in a dose-dependent manner, showed potential protection against testicular toxicity, reversed the disrupted testicular function, and improved histological alterations through rebalancing of oxidative stress, inflammation, and apoptosis. In addition, cilostazol exerted a more pronounced protective effect in comparison to tadalafil and pentoxifylline. In conclusion, cilostazol ameliorates cisplatin-induced testicular impairment through alteration of oxidative stress, inflammation, and apoptotic pathways, offering a promising treatment for cisplatin-induced testicular damage.

Peripheral Nerve Denervation in Streptozotocin-Induced Diabetic Rats Is Reduced by Cilostazol

Background and Objective: Our previous study demonstrated that consistent treatment of oral cilostazol was effective in reducing levels of painful peripheral neuropathy in streptozotocin-induced type I diabetic rats. As diabetic neuropathy is characterized by hyperglycemia-induced nerve damage in the periphery, this study aims to examine the neuropathology as well as the effects of cilostazol treatments on the integrity of peripheral small nerve fibers in type I diabetic rats. Materials and Methods: A total of ninety adult male Sprague-Dawley rats were divided into the following groups: (1) naïve (control) group; (2) diabetic rats (DM) group for 8 weeks; DM rats receiving either (3) 10 mg/kg oral cilostazol (Cilo10), (4) 30 mg/kg oral cilostazol (Cilo30), or (5) 100 mg/kg oral cilostazol (Cilo100) for 6 weeks. Pain tolerance thresholds of hind paws toward thermal and mechanical stimuli were assessed. Expressions of PGP9.5, P2X3, CGRP, and TRPV-1 targeting afferent nerve fibers in hind paw skin and glial cells in the spinal dorsal horn were examined via immunohistochemistry and immunofluorescence. Results: Oral cilostazol ameliorated the symptoms of mechanical allodynia but not thermal analgesia in DM rats. Significant reductions in PGP9.5-, P2X3-, CGRP, and TRPV-1-labeled penetrating nerve fibers in the epidermal layer indicated denervation of sensory nerves in the hind paw epidermis of DM rats. Denervation significantly improved in groups that received Cilo30 and Cilo100 in a dose-dependent manner. Cilostazol administration also suppressed microglial hyperactivation and increased astrocyte expressions in spinal dorsal horns. Conclusions: Oral cilostazol ameliorated hyperglycemia-induced peripheral small nerve fiber damage in the periphery of diabetic rats and effectively mitigated diabetic neuropathic pain via a central sensitization mechanism. Our findings present cilostazol not only as an effective option for managing symptoms of neuropathy but also for deterring the development of diabetic neuropathy in the early phase of type I diabetes.

Observational case-control study of small-fiber neuropathies, with regards on smoking and vitamin D deficiency and other possible causes

Introduction

Small fiber neuropathies (SFNs) are disorders of skin nerve endings inducing pruritus, burning pain, numbness, and paresthesia. The aims of this study were to search for putative etiologies of SFN and their occurrence in a cohort of patients and to compare patients with SFN to a group of patients without SFN to highlight potential factors associated with SFN.

Methods

This study was observational, retrospective, and monocentric. All patients with symptoms of SFN who underwent skin biopsies with intraepidermal nerve density counts were included. Patients with a count lower than 5 percentiles were considered to be in the SFN group. Other patients were considered to be the control group.

Results

A total of 162 patients with SFN and 161 controls were included. No cause was identified for 108 patients (61.7%). The established causes were autoimmune diseases (9.1%), diabetes or glucose intolerance (8%), medication (4%), liver disease (3.4%), and monoclonal gammopathy of undetermined significance (2.9%). Current or former smokers were more numerous in the SFN group (26.5%) than in the control group (16.1%), while vitamin D amounts were significantly lower in the SFN group than in the control group.

Discussion

Hence, tobacco smoking and vitamin D deficiency might be new putative causes of SFN.

The Role of Platelets in Diabetic Kidney Disease

Diabetic kidney disease (DKD) is among the most common microvascular complications in patients with diabetes, and it currently accounts for the majority of end-stage kidney disease cases worldwide. The pathogenesis of DKD is complex and multifactorial, including systemic and intra-renal inflammatory and coagulation processes. Activated platelets play a pivotal role in inflammation, coagulation, and fibrosis. Mounting evidence shows that platelets play a role in the pathogenesis and progression of DKD. The potentially beneficial effects of antiplatelet agents in preventing progression of DKD has been studied in animal models and clinical trials. This review summarizes the current knowledge on the role of platelets in DKD, including the potential therapeutic effects of antiplatelet therapies.

A Randomized Controlled Trial Evaluating Outcome Impact of Cilostazol in Patients with Coronary Artery Disease or at a High Risk of Cardiovascular Disease

Previous studies found that cilostazol has a favorable effect on glucose and lipid homeostasis, endothelial function, atherosclerosis, and vasculo-angiogenesis. However, it is poorly understood whether these effects can translate into better clinical outcomes. This study investigated the outcome effect of cilostazol in patients with coronary artery disease (CAD) or at a high risk of cardiovascular (CV) disease. We conducted a randomized, double-blind, placebo-controlled trial involving 266 patients who received cilostazol, 200 mg/day (n = 134) or placebo (n = 132). Pre-specified clinical endpoints including composite major adverse cardiovascular events (MACE) (CV death, non-fatal myocardial infarct, non-fatal stroke, hospitalization for heart failure, or unplanned coronary revascularization), the composite major coronary event (MCE) and major adverse CV and cerebrovascular event (MACCE), were prospectively assessed. The mean duration of follow-up was 2.9 years. Relative to placebo, cilostazol treatment had a borderline effect on risk reduction of MACE (hazard ratio [HR], 0.67; 95% confidence interval (CI), 0.34–1.33), whereas the beneficial effect in favor of cilostazol was significant in patients with diabetes mellitus or a history of percutaneous coronary intervention (p for interaction, 0.02 and 0.06, respectively). Use of cilostazol, significantly reduced the risk of MCE (HR, 0.38; 95% CI, 0.17–0.86) and MACCE (HR, 0.47; 95% CI, 0.23–0.96). A significantly lower risk of angina pectoris (HR, 0.38; 95% CI, 0.17–0.86) was also observed in the cilostazol group. After multi-variable adjustment, cilostazol treatment independently predicted a lower risk of MCE. In conclusion, these results suggest cilostazol may have beneficial effects in patients with CAD or at a high risk of CV disease.

The spectrum and systemic associations of microvascular dysfunction in the heart and other organs

Microvascular dysfunction (MVD) contributes to several conditions that increase morbidity and mortality, including ischemic heart disease, heart failure, dementia, chronic kidney disease and hypertension. Consequently, MVD imposes a substantial burden on healthcare systems worldwide. In comparison to macrovascular dysfunction, MVD has been incompletely investigated, and it remains uncertain whether MVD in an organ constitutes a distinct pathology or a manifestation of a systemic disorder. Here, we summarize and appraise the techniques that are used to diagnose MVD. We review the disorders of the heart, brain and kidneys in which the role of MVD has been highlighted and summarize evidence hinting at a systemic or multi-organ nature of MVD. Finally, we discuss the benefits and limitations of implementing MVD testing in clinical practice with a focus on new interventions that are beginning to emerge.

Cilostazol Ameliorates Peripheral Neuropathic Pain in Streptozotocin-Induced Type I Diabetic Rats

Background: Cilostazol is an antiplatelet agent with vasodilating, endothelial function restoration, and anti-inflammatory effects. This study aims to investigate the efficacy of oral cilostazol for preventing the development of diabetic peripheral neuropathy (DPN).

Materials and Methods: Ninety adult male Sprague-Dawley rats were divided into five groups: 1) naïve (control); 2) diabetic (DM); 3) DM receiving 10 mg/kg cilostazol (cilo-10); 4) DM receiving 30 mg/kg cilostazol (cilo-30); and 5) DM receiving 100 mg/kg cilostazol (cilo-100). Hindpaw responses to thermal and mechanical stimuli were measured. Activation of microglia and astrocytes in the spinal dorsal horn (SDH) and expression of NaVs in the dorsal root ganglia (DRG) were examined with Western blots and immunofluorescence.

Results: DM rats displayed decreased withdrawal thresholds to mechanical stimuli (mechanical allodynia) and blunted responses to thermal stimuli. In addition, the expression of microglia increased, but astrocytes were reduced in the SDH. Upregulation of Nav −1.1, 1.2, −1.3, −1.6, and −1.7 and downregulation of Nav-1.8 were observed in the DRG. The DM rats receiving cilostazol all returned DM-induced decrease in withdrawal threshold to mechanical stimuli and attenuated neuropathic pain. Additionally, all cilostazol treatments suppressed the level of activated microglial cells and ameliorated the DM-induced decline in astrocyte expression levels in the SDH. However, only the rats treated with cilo-100 demonstrated significant improvements to the aberrant NaV expression in the DRG.

Conclusion: Oral cilostazol can blunt the responses of mechanical allodynia and has the potential to treat diabetic neuropathy by attenuating NaV and glial cell dysregulation.

Effect of cilostazol on arteriovenous fistula in hemodialysis patients

BACKGROUND

The maturation and patency of permanent vascular access are critical in patients requiring hemodialysis. Although numerus trials have been attempted to achieve permanently patent vascular access, little have been noticeable. Cilostazol, a phosphodiesterase-3 inhibitor, has been shown to be effective in peripheral arterial disease including vascular injury-induced intimal hyperplasia. We therefore aimed to determine the effect of cilostazol on the patency and maturation of permanent vascular access.

METHODS

This single-center, retrospective study included 194 patients who underwent arteriovenous fistula surgery to compare vascular complications between the cilostazol (n=107) and control (n=87) groups.

RESULTS

The rate of vascular complications was lower in the cilostazol group than in the control group (36.4% vs. 51.7%; p=0.033), including maturation failure (2.8% vs. 11.5%; p=0.016). The rate of reoperation due to vascular injury after hemodialysis initiation following fistula maturation was also significantly lower in the cilostazol group than in the control group (7.5% vs. 28.7%; p<0.001). However, there were no significant differences in the requirement for percutaneous transluminal angioplasty (PTA), rate of PTA, and the interval from arteriovenous fistula surgery to PTA between the cilostazol and control groups.

CONCLUSION

Cilostazol might be beneficial for the maturation of permanent vascular access in patients requiring hemodialysis.

Cilostazol for Secondary Stroke Prevention: History, Evidence, Limitations, and Possibilities

Cilostazol is a PDE3 (phosphodiesterase III) inhibitor with a long track record of safety that is Food and Drug Administration and European Medicines Agency approved for the treatment of claudication in patients with peripheral arterial disease. In addition, cilostazol has been approved for secondary stroke prevention in several Asian countries based on trials that have demonstrated a reduction in stroke recurrence among patients with noncardioembolic stroke. The onset of benefit appears after 60 to 90 days of treatment, which is consistent with cilostazol's pleiotropic effects on platelet aggregation, vascular remodeling, blood flow, and plasma lipids. Cilostazol appears safe and does not increase the risk of major bleeding when given alone or in combination with aspirin or clopidogrel. Adverse effects such as headache, gastrointestinal symptoms, and palpitations, however, contributed to a 6% increase in drug discontinuation among patients randomized to cilostazol in a large secondary stroke prevention trial (CSPS.com [Cilostazol Stroke Prevention Study for Antiplatelet Combination]). Due to limitations of prior trials, such as open-label design, premature trial termination, large loss to follow-up, lack of functional or cognitive outcome data, and exclusive enrollment in Asia, the existing trials have not led to a change in clinical practice or guidelines in Western countries. These limitations could be addressed by a double-blind placebo-controlled randomized trial conducted in a broader population. If positive, it would increase the evidence in support of long-term treatment with cilostazol for secondary prevention in the millions of patients worldwide who have experienced a noncardioembolic ischemic stroke.

Vascular Endothelial Repair and the Influence of Circulating Antiplatelet Drugs in a Carotid Coil Model

Background:

Clinicians may choose to administer antiplatelet medications to patients with cerebral aneurysms following endovascular coiling to prevent thrombus formation and vascular occlusion, if they fear a thrombus will form on the platinum wire where it diverges into the vessel from the aneurysm sac. However, the mechanism by which vascular endothelial cells repair a vessel in the living body in the event of a coil deviation and the effects of antiplatelet drugs on these cells have not been fully elucidated. We aimed to investigate the association between endothelial progenitor cells (EPCs) and endothelium formation at the surface of the platinum coils deployed in the carotid artery of rats, and to determine the effects of different antiplatelet drugs on this process.

Subjects and Methods:

We established an experimental model using normal and diabetic rats at 12 months of age. The diabetic rats were assigned to 4 different diet groups, distinguished by whether they were fed plain rat feed, or the same feed supplemented by 1 of 3 antiplatelet drugs (cilostazol, aspirin, or clopidogrel: all 0.1%) for 2 weeks, and the carotid artery was perforated by an embolization coil (“carotid coil model”). We monitored the process by which vascular endothelial cells formed the new endothelium on the surface of the coil by sampling and evaluating the region at 1, 2, and 4 weeks after placement. This repair process was also compared among 3 groups treated with different antiplatelet drugs (i.e. aspirin, clopidogrel, and cilostazol). One-way analysis of variance tests were performed to evaluate the differences in vascular thickness between groups, and P < .05 was considered statistically significant.

Results:

The diabetic rats showed delayed neoendothelialization and marked intimal hyperplasia. Cilostazol and clopidogrel effectively counteracted this delayed endothelial repair process. Flk1 immunostaining revealed greater expression in the diabetic rats administered cilostazol, second only to normal rats, suggesting that this agent acted to recruit EPCs.

Conclusion:

Neoendothelialization is delayed when vascular endothelial cells fail to function normally, which consequently leads to the formation of hyperplastic tissue. Cilostazol may remedy this dysfunction by recruiting EPCs to the site of injury.

Effect of cilostazol on arteriovenous fistula in hemodialysis patients

BACKGROUND

The maturation and patency of permanent vascular access are critical in patients requiring hemodialysis. Although numerus trials have been attempted to achieve permanently patent vascular access, little have been noticeable. Cilostazol, a phosphodiesterase-3 inhibitor, has been shown to be effective in peripheral arterial disease including vascular injury-induced intimal hyperplasia. We therefore aimed to determine the effect of cilostazol on the patency and maturation of permanent vascular access.

METHODS

This single-center, retrospective study included 194 patients who underwent arteriovenous fistula surgery to compare vascular complications between the cilostazol (n=107) and control (n=87) groups.

RESULTS

The rate of vascular complications was lower in the cilostazol group than in the control group (36.4% vs. 51.7%; p=0.033), including maturation failure (2.8% vs. 11.5%; p=0.016). The rate of reoperation due to vascular injury after hemodialysis initiation following fistula maturation was also significantly lower in the cilostazol group than in the control group (7.5% vs. 28.7%; p<0.001). However, there were no significant differences in the requirement for percutaneous transluminal angioplasty (PTA), rate of PTA, and the interval from arteriovenous fistula surgery to PTA between the cilostazol and control groups.

CONCLUSION

Cilostazol might be beneficial for the maturation of permanent vascular access in patients requiring hemodialysis.

Role of Phosphodiesterase in the Biology and Pathology of Diabetes

Glucose metabolism is the initiator of a large number of molecular secretory processes in β cells. Cyclic nucleotides as a second messenger are the main physiological regulators of these processes and are functionally divided into compartments in pancreatic cells. Their intracellular concentration is limited by hydrolysis led by one or more phosphodiesterase (PDE) isoenzymes. Literature data confirmed multiple expressions of PDEs subtypes, but the specific roles of each in pancreatic β-cell function, particularly in humans, are still unclear. Isoforms present in the pancreas are also found in various tissues of the body. Normoglycemia and its strict control are supported by the appropriate release of insulin from the pancreas and the action of insulin in peripheral tissues, including processes related to homeostasis, the regulation of which is based on the PDE- cyclic AMP (cAMP) signaling pathway. The challenge in developing a therapeutic solution based on GSIS (glucose-stimulated insulin secretion) enhancers targeted at PDEs is the selective inhibition of their activity only within β cells. Undeniably, PDEs inhibitors have therapeutic potential, but some of them are burdened with certain adverse effects. Therefore, the chance to use knowledge in this field for diabetes treatment has been postulated for a long time.

Mechanisms behind Retinal Ganglion Cell Loss in Diabetes and Therapeutic Approach

Diabetes produces several changes in the body triggered by high glycemia. Some of these changes include altered metabolism, structural changes in blood vessels and chronic inflammation. The eye and particularly the retinal ganglion cells (RGCs) are not spared, and the changes eventually lead to cell loss and visual function impairment. Understanding the mechanisms resulting in RGC damage and loss from diabetic retinopathy is essential to find an effective treatment. This review focuses mainly on the signaling pathways and molecules involved in RGC loss and the potential therapeutic approaches for the prevention of this cell death. Throughout the manuscript it became evident that multiple factors of different kind are responsible for RGC damage. This shows that new therapeutic agents targeting several factors at the same time are needed. Alpha-1 antitrypsin as an anti-inflammatory agent may become a suitable option for the treatment of RGC loss because of its beneficial interaction with several signaling pathways involved in RGC injury and inflammation. In conclusion, alpha-1 antitrypsin may become a potential therapeutic agent for the treatment of RGC loss and processes behind diabetic retinopathy.

Cilostazol use is associated with FIM cognitive improvement during convalescent rehabilitation in patients with ischemic stroke: a retrospective study

Cilostazol is a phosphodiesterase III-inhibiting antiplatelet agent that is often used to prevent stroke and peripheral artery disease, and its administration has shown significant improvements for cognitive impairment. We investigate the potential of cilostazol for reducing or restoring cognitive decline during convalescent rehabilitation in patients with non-cardioembolic ischemic stroke. The study sample included 371 consecutive patients with lacunar (n = 44) and atherothrombosis (n = 327) subtypes of non-cardioembolic ischemic stroke (224 men and 147 women; mean age, 72.9 ± 8.1 years) who were required for inpatient convalescent rehabilitation. Their medical records were retrospectively surveyed to identify those who had received cilostazol (n = 101). Patients were grouped based on cilostazol condition, and Functional Independence Measure (FIM) scores (total and motor or cognitive subtest scores) were assessed both at admission and discharge. The gain and efficiency in FIM cognitive scores from admission to discharge were significantly higher in patients who received cilostazol than those who did not (p = 0.047 and p = 0.035, respectively); we found no significant differences in other clinical factors or scores. Multiple linear regression analysis confirmed that cilostazol was a significant factor in FIM cognitive scores at discharge (β = 0.041, B = 0.682, p = 0.045); the two tested dosages were not significantly different (100 mg/day, n = 43; 200 mg/day, n = 58). Cilostazol can potentially improve cognitive function during convalescent rehabilitation of patients with non-cardioembolic ischemic stroke, although another research must be needed to confirm this potential.

Treatment of coronary microvascular dysfunction

Contemporary data indicate that patients with signs and symptoms of ischaemia and non-obstructive coronary artery disease (INOCA) often have coronary microvascular dysfunction (CMD) with elevated risk for adverse outcomes. Coronary endothelial (constriction with acetylcholine) and/or microvascular (limited coronary flow reserve with adenosine) dysfunction are well-documented, and extensive non-obstructive atherosclerosis is often present. Despite these data, patients with INOCA currently remain under-treated, in part, because existing management guidelines do not address this large, mostly female population due to the absence of evidence-based data. Relatively small sample-sized, short-term pilot studies of symptomatic mostly women, with INOCA, using intense medical therapies targeting endothelial, microvascular, and/or atherosclerosis mechanisms suggest symptom, ischaemia, and coronary vascular functional improvement, however, randomized, controlled outcome trials testing treatment strategies have not been completed. We review evidence regarding CMD pharmacotherapy. Potent statins in combination with angiotensin-converting enzyme inhibitor (ACE-I) or receptor blockers if intolerant, at maximally tolerated doses appear to improve angina, stress testing, myocardial perfusion, coronary endothelial function, and microvascular function. The Coronary Microvascular Angina trial supports invasive diagnostic testing with stratified therapy as an approach to improve symptoms and quality of life. The WARRIOR trial is testing intense medical therapy of high-intensity statin, maximally tolerated ACE-I plus aspirin on longer-term outcomes to provide evidence for guidelines. Novel treatments and those under development appear promising as the basis for future trial planning.

Microvascular Disease Increases Amputation in Patients With Peripheral Artery Disease

It is estimated that >2 million patients are living with an amputation in the United States. Peripheral artery disease (PAD) and diabetes mellitus account for the majority of nontraumatic amputations. The standard measurement to diagnose PAD is the ankle-brachial index, which integrates all occlusive disease in the limb to create a summary value of limb artery occlusive disease. Despite its accuracy, ankle-brachial index fails to well predict limb outcomes. There is an emerging body of literature that implicates microvascular disease (MVD; ie, retinopathy, nephropathy, neuropathy) as a systemic phenomenon where diagnosis of MVD in one capillary bed implicates microvascular dysfunction systemically. MVD independently associates with lower limb outcomes, regardless of diabetic or PAD status. The presence of PAD and concomitant MVD phenotype reveal a synergistic, rather than simply additive, effect. The higher risk of amputation in patients with MVD, PAD, and concomitant MVD and PAD should prompt aggressive foot surveillance and diagnosis of both conditions to maintain ambulation and prevent amputation in older patients.

Progress in the Mechanism and Clinical Application of Cilostazol

Cilostazol is a unique platelet inhibitor that has been used clinically for more than 20 years. As a phosphodiesterase type III inhibitor, cilostazol is capable of reversible inhibition of platelet aggregation and vasodilation, has antiproliferative effects, and is widely used in the treatment of peripheral arterial disease, cerebrovascular disease, percutaneous coronary intervention, etc. This article briefly reviews the pharmacological mechanisms and clinical application of cilostazol.

Cilostazol Promotes Angiogenesis and Increases Cell Proliferation After Myocardial Ischemia-Reperfusion Injury Through a cAMP-Dependent Mechanism

PURPOSE

Previous study indicated the protective role of cilostazol in ischemia-reperfusion (I/R) injury. Here, we aimed to explore the function of cilostazol in myocardial I/R injury and the underlying mechanism.

METHODS

The myocardial I/R injury rat model was constructed, and the expression levels of vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), basic fibroblast growth factor (bFGF), platelet-derived growth factor receptor b (PDGF-B) and the number of new blood vessels were measured by qRT-PCR and immunohistochemistry. VSMC and HUVEC cells were treated with hypoxia to induce in vivo I/R injury model. The protein expression of AKT, endothelial nitric oxide synthase (eNOS) and apoptosis-related protein levels were detected by western blotting. Besides, the positive staining rate and cell viability were tested by 5-bromo-2-deoxyuridine (Brdu)/4',6-diamidino-2-phenylindole (DAPI) or DAPI/TdT-mediated dUTP Nick-End Labeling (TUNEL) staining and MTT assay.

RESULTS

Cilostazol promoted angiogenesis by increasing the number of new blood vessels and up-regulating the expression of VEGF, HGF, bFGF and PDGF-B in myocardial I/R-injury rat model. The in vitro experiments showed that cilostazol increased the level of eNOS and AKT, and also enhanced cell proliferation in hypoxia-treated VSMC and HUVEC cells. Furthermore, after 8-Br-cAMP treatment, VEGF, HGF, bFGF, PDGF-B, p-AKT and p-eNOS expression were up-regulated, while cleaved-caspase 3 and cleaved-PARP expression were down-regulated. In addition, the effects of cilostazol on cell viability and apoptosis were aggravated by 8-Br-cAMP and attenuated after KT-5720 treatment.

CONCLUSION

Cilostazol could promote angiogenesis, increase cell viability and inhibit cell apoptosis, consequently protecting myocardial tissues against I/R-injury through activating cAMP.

Therapeutic targeting of 3',5'-cyclic nucleotide phosphodiesterases: inhibition and beyond

Phosphodiesterases (PDEs), enzymes that degrade 3',5'-cyclic nucleotides, are being pursued as therapeutic targets for several diseases, including those affecting the nervous system, the cardiovascular system, fertility, immunity, cancer and metabolism. Clinical development programmes have focused exclusively on catalytic inhibition, which continues to be a strong focus of ongoing drug discovery efforts. However, emerging evidence supports novel strategies to therapeutically target PDE function, including enhancing catalytic activity, normalizing altered compartmentalization and modulating post-translational modifications, as well as the potential use of PDEs as disease biomarkers. Importantly, a more refined appreciation of the intramolecular mechanisms regulating PDE function and trafficking is emerging, making these pioneering drug discovery efforts tractable.

Vardenafil and cilostazol can improve vascular reactivity in rats with diabetes mellitus and rheumatoid arthritis co-morbidity

Endothelial dysfunction and vascular reactivity defects secondary to metabolic and immunological disorders carry risk of serious cardiovascular complications. Here, the effects of the phosphodiesterase (PDE) inhibitors vardenafil and cilostazol were examined against rheumatoid arthritis (RA)/diabetes mellitus (DM)-co-morbidity-induced endothelial dysfunction and vascular reactivity defects. After setting of RA/DM-co-morbidity model, rats were divided into a normal control group, an RA/DM-co-morbidity group, and two treatment groups receiving oral vardenafil (10 mg/kg/day) and cilostazol (30 mg/kg/day) for 21 days after RA/DM-co-morbidity induction. Aorta was isolated for biochemical estimations of the pro-inflammatory vasoconstrictor molecules angiotensin-II (Ang-II) and endothelin-1 (ET-1), the adhesion molecules P-selectin and vascular cell adhesion molecule-1 (VCAM-1), the energy sensor adenosine-5'-monophosphate-activated protein kinase (AMPK), and the vasodilator anti-inflammatory molecule vasoactive intestinal peptide (VIP) using enzyme-linked immunosorbent assay (ELISA) and western blot analysis. Immunohistochemical estimations of endothelial nitric oxide synthase (eNOS) and matrix metalloproteinase (MMP)-2 were performed coupled with histopathological examination using routine hematoxylin and eosin (H&E) and special Masson trichrome staining. The in vitro study was conducted using aortic strips where cumulative concentration response curves were done for the endothelium-dependent relaxing factor acetylcholine and the endothelium-independent relaxing factor sodium nitroprusside after submaximal contraction with phenylephrine. Vardenafil and cilostazol significantly improved endothelial integrity biomarkers in vivo supported with histopathological findings in addition to improved vasorelaxation in vitro. Apart from their known PDE inhibition, up-regulation of vascular AMPK and eNOS coupled with down-regulation of Ang-II, ET-1, P-selectin, VCAM-1 and MMP-2 may explain vardenafil and cilostazol protective effect against RA/DM-co-morbidity-induced endothelial dysfunction and vascular reactivity defects.

Comparison of efficacy between trimetazidine and cilostazol in the treatment of arteriosclerosis obliterans in lower extremity

This study compared the efficacy and long-term survival rate of trimetazidine and cilostazol in the treatment of lower extremity arteriosclerosis obliterans (ASO). A retrospectively analysis on the medical records of 206 patients with ASO who were admitted to The Central Hospital of Wuhan from January 2011 to May 2013 was performed, including 94 patients treated with trimetazidine (group A) and 112 patients treated with cilostazol (group B). On the basis of the same basic treatment, both groups were applied with these two drugs after two courses of treatments. Then the efficacy of clinical treatment, dorsal artery blood flow, anterior femoral artery, posterior tibial artery blood flow, brachial artery index, toe-brachial index, painless walking distance, maximum walking distance, adverse reactions, 5-year survival rates were compared. The total effective rate of clinical efficacy in group B was higher than group A (P<0.05). After the first course of treatment, the above indicators increased in both groups (P<0.05). After the end of the second course of treatment, the above-mentioned index values in both groups were significantly increased (P<0.05). The improvement of the above indicators in group B were better than the trimetazidine group in both the first and second treatment courses (P<0.05). In group A, there were 15 cases of patients with lethargy and hypodynamia and 9 cases of dizziness and headache. There were significant differences between the 7th and 3rd cases of patients when compared to group B (P<0.05). The 5-year survival rate of group A was lower than group B (P<0.05). The clinical efficacy of cliostazol in the treatment of ASO had a good effect, and there was only a few adverse reactions and the long-term survival rate was high. It is worthy of being promoted in clinical practice.