Olprinone, a Selective Phosphodiesterase III Inhibitor, Has Protective Effects in a Septic Rat Model after Partial Hepatectomy and Primary Rat Hepatocyte.

Olprinone (OLP) is a selective inhibitor of phosphodiesterase III and is used clinically in patients with heart failure and those undergoing cardiac surgery; however, little is known about the effects of OLP on hepatoprotection. The purpose of this study aimed to determine whether OLP has protective effects in in vivo and in vitro rat models of endotoxin-induced liver injury after hepatectomy and to clarify the mechanisms of action of OLP. In the in vivo model, rats underwent 70% partial hepatectomy and lipopolysaccharide treatment (PH/LPS). OLP administration increased survival by 85.7% and decreased tumor necrosis factor-α, C-X-C motif chemokine ligand 1, and inducible nitric oxide synthase (iNOS) mRNA expression in the livers of rats treated with PH/LPS. OLP also suppressed nuclear translocation and/or DNA binding ability of nuclear factor kappa B (NF-κB). Pathological liver damage induced by PH/LPS was alleviated and neutrophil infiltration was reduced by OLP. Primary cultured rat hepatocytes treated with the pro-inflammatory cytokine interleukin-1ß (IL-1ß) were used as a model of in vitro liver injury. Co-treatment with OLP inhibited dose-dependently IL-1ß-stimulated iNOS induction and NF-κB activation. Our results demonstrate that OLP may partially inhibit the induction of several inflammatory mediators through the suppression of NF-κB and thus prevent liver injury induced by endotoxin after liver resection.

Cilostazol improves the prognosis after hepatectomy in rats with sinusoidal obstruction syndrome.

BACKGROUND AND AIM: Safe radical hepatectomy is important for patients with colorectal liver metastases complicated by sinusoidal obstruction syndrome (SOS) after oxaliplatin-based chemotherapy. This study aimed to investigate the impact of preoperative administration of cilostazol (CZ), an oral selective phosphodiesterase III inhibitor, on hepatectomy in rat SOS model. MATERIAL AND METHODS: Rats were divided into NL (normal liver), SOS (monocrotaline [MCT]-treated), and SOS + CZ (MCT + CZ-treated) groups. MCT or CZ was administered orally, and a 30% partial hepatectomy was performed 48 h after MCT administration. Postoperative survival rates were evaluated (n = 9, for each). Other rats were sacrificed on postoperative days (POD) 1 and 3 and evaluated histologically, immunohistochemically, biochemically, and using transmission electron microscopy (TEM), focusing particularly on SOS findings, liver damage, and liver sinusoidal endothelial cell (LSEC) injury. RESULTS: The cumulative 10-day postoperative survival rate was significantly higher in the SOS + CZ group than in the SOS group (88.9% vs 33.3%, P = 0.001). Total SOS scores were significantly lower in the SOS + CZ group than in the SOS group on both POD 1 and 3. Serum biochemistry and immunohistochemistry showed that CZ reduced liver damage after hepatectomy. TEM revealed that LSECs were significantly preserved morphologically in the SOS + CZ group than in the SOS group on POD 1 (86.1 ± 8.2% vs 63.8 ± 9.3%, P = 0.003). CONCLUSION: Preoperative CZ administration reduced liver injury by protecting LSECs and improved the prognosis after hepatectomy in rats with SOS.

Cilostazol Stimulates Angiogenesis and Accelerates Fracture Healing in Aged Male and Female Mice by Increasing the Expression of PI3K and RUNX2.

Fracture healing in the aged is associated with a reduced healing capacity, which often results in delayed healing or non-union formation. Many factors may contribute to this deterioration of bone regeneration, including a reduced 'angiogenic trauma response'. The phosphodiesterase-3 (PDE-3) inhibitor cilostazol has been shown to exert pro-angiogenic and pro-osteogenic effects in preclinical studies. Therefore, we herein analyzed in a stable closed femoral fracture model whether this compound also promotes fracture healing in aged mice. Forty-two aged CD-1 mice (age: 16-18 months) were daily treated with 30 mg/kg body weight cilostazol (n = 21) or vehicle (control, n = 21) by oral gavage. At 2 and 5 weeks after fracture, the femora were analyzed by X-ray, biomechanics, micro-computed tomography (µCT), histology, immunohistochemistry, and Western blotting. These analyses revealed a significantly increased bending stiffness at 2 weeks (2.2 ± 0.4 vs. 4.3 ± 0.7 N/mm) and an enhanced bone formation at 5 weeks (4.4 ± 0.7 vs. 9.1 ± 0.7 mm3) in cilostazol-treated mice when compared to controls. This was associated with a higher number of newly formed CD31-positive microvessels (3.3 ± 0.9 vs. 5.5 ± 0.7 microvessels/HPF) as well as an elevated expression of phosphoinositide-3-kinase (PI3K) (3.6 ± 0.8 vs. 17.4 ± 5.5-pixel intensity × 104) and runt-related transcription factor (RUNX)2 (6.4 ± 1.2 vs. 18.2 ± 2.7-pixel intensity × 104) within the callus tissue. These findings indicate that cilostazol accelerates fracture healing in aged mice by stimulating angiogenesis and the expression of PI3K and RUNX2. Hence, cilostazol may represent a promising compound to promote bone regeneration in geriatric patients.

Post-stroke treatment with K-134, a phosphodiesterase 3 inhibitor, improves stroke outcomes in the stroke-prone spontaneously hypertensive rat model-A comparative evaluation of antiplatelet drugs.

Post-stroke antiplatelet therapy has been proved to reduce the risk of recurrent stroke; however, it may also increase the incidence of intracranial hemorrhage that could offset any benefits. Therefore, the balance between the benefits and risks of antiplatelet drugs is a critical issue to consider. In the present study, we have compared the effects of post-stroke administration of antiplatelet agents on functional outcomes in the stroke-prone spontaneously hypertensive rat (SHRSP), an established animal model that mimics human lacunar stroke and cerebral small vessel disease. We confirmed that a potent phosphodiesterase 3 (PDE3) inhibitor, K-134, significantly improved post-stroke survival rate and survival time, attenuated stroke-induced neurological deficits, and decreased the incidence of cerebral lesion caused by intracerebral hemorrhage and softening. Similarly, cilostazol showed beneficial effects, though to a lower extent with respect to the survival outcome and neurological symptoms. On the other hand, a P2Y12 inhibitor, clopidogrel significantly improved survival outcomes at the higher dose but caused massive bleeding in the brain at both low and high doses. In contrast, no hemorrhagic lesion was observed in K-134-treated SHRSPs despite its antiplatelet activity. Our findings indicate that K-134 may have a superior post-stroke therapeutic outcome in comparison to other antiplatelet drugs.

Could cilostazol be beneficial in COVID-19 treatment? Thinking about phosphodiesterase-3 as a therapeutic target.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19) that has emerged and rapidly spread across the world. The COVID-19 severity is associated to viral pneumonia with additional extrapulmonary complications. Hyperinflammation, dysfunctional immune response and hypercoagulability state are associated to poor prognosis. Therefore, the repositioning of multi-target drugs to control the hyperinflammation represents an important challenge for the scientific community. Cilostazol, a selective phosphodiesterase type-3 inhibitor (PDE-3), is an antiplatelet and vasodilator drug, that presents a range of pleiotropic effects, such as antiapoptotic, anti-inflammatory, antioxidant, and cardioprotective activities. Cilostazol also can inhibit the adenosine uptake, which enhances intracellular cAMP levels. In the lungs, elevated cAMP promotes anti-fibrotic, vasodilator, antiproliferative effects, as well as mitigating inflammatory events. Interestingly, a recent study evaluated antiplatelet FDA-approved drugs through molecular docking-based virtual screening on viral target proteins. This study revealed that cilostazol is a promising drug against COVID-19 by inhibiting both main protease (Mpro) and Spike glycoprotein, reinforcing its use as a promising therapeutic approach for COVID-19. Considering the complexity associated to COVID-19 pathophysiology and observing its main mechanisms, this article raises the hypothesis that cilostazol may act on important targets in development of the disease. This review highlights the importance of drug repurposing to address such an urgent clinical demand safely, effectively and at low cost, reinforcing the main pharmacological actions, to support the hypothesis that a multi-target drug such as cilostazol could play an important role in the treatment of COVID-19.

Literature review and meta-analysis of the efficacy of cilostazol on limb salvage rates after infrainguinal endovascular and open revascularization.

BACKGROUND: Current clinical guidelines recommend the use of cilostazol in the treatment of patients with infrainguinal peripheral artery disease (PAD) who experience intermittent claudication. However, the role of cilostazol therapy in patients with advanced PAD and critical limb ischemia (CLI) remains unclear. To conduct a meta-analysis of randomized controlled trials and cohort studies that evaluated the effect of cilostazol vs standard antiplatelet therapy on limb-related and arterial patency-related outcomes. We also reviewed literature pertinent to the effect of cilostazol on wound healing in patients with advanced PAD. METHODS: We performed a MEDLINE, EMBASE, COCHRANE (CENTRAL), SCOPUS, and US Clinical Trials database search for all trials and studies since 1999 that compared cilostazol with standard antiplatelet therapy in the setting of infrainguinal PAD revascularization procedures (endovascular or open). Aggregate data was collected from four randomized control trials and six retrospective cohort studies. The end point incidence ratios and treatment effects were generated from each study and reported as hazard ratios (HR) using a random-effect model. We also reviewed 10 studies that evaluated the effect of cilostazol on wound healing in patients with advanced PAD. RESULTS: From more than 25,000 total patients, 3136 patients met our inclusion criteria. All patients had at least lifestyle-impacting intermittent claudication, and more than 50% met the definition of CLI (Rutherford class ≥4). Patient age range was 53 to 83 years, and the majority were male (66%). The mean follow-up time averaged 2 years across all studies. Meta-analysis revealed that cilostazol treatment favored amputation-free survival (hazard ratio [HR], 0.79; 95% confidence interval [CI], 0.69-0.91), limb salvage rate (HR, 0.42; 95% CI, 0.27-0.66), decreased repeat revascularization (risk ratio [RR], 0.44; 95% CI, 0.37-0.52), and decreased restenosis (RR, 0.68; 95% CI, 0.61-0.76). Cilostazol treatment also increased freedom from target lesion revascularization (RR, 1.35; 95% CI, 1.21-1.53) with no difference in all-cause mortality. Effective wound healing was found to be an inconsistent outcome measure in patients receiving cilostazol therapy. CONCLUSIONS: We observed that cilostazol therapy has a beneficial impact on all limb-related and arterial patency-related outcomes, but no effect on all-cause mortality in patients with advanced PAD and CLI undergoing revascularization procedures. Additional studies are needed to evaluate the effect of cilostazol therapy on wound healing in patients with advanced PAD.

Pretreatment with a Phosphodiesterase-3 Inhibitor, Milrinone, Reduces Hepatic Ischemia-Reperfusion Injury, Minimizing Pericentral Zone-Based Liver and Small Intestinal Injury in Rats.

BACKGROUND Severe pericentral zone (zone 3)-based liver injury (LI) may become intractable, with allograft dysfunction after liver transplantation. The phosphodiesterase-3 inhibitor, milrinone, has been reported to attenuate hepatic ischemia-reperfusion injury (IRI). This study clarified how hepatic IRI involved zone 3-based LI, in which zone milrinone was effective, and whether milrinone could improve small intestinal injury (SII) with hepatic IRI. MATERIAL AND METHODS Rats were divided into sham, ischemia-reperfusion (IR), or IR+milrinone groups (n=13 per group). Milrinone was administered intraportally via intrasplenic injection, and whole hepatic ischemia was induced for 30 min. Five hours after reperfusion, serum chemistry and histopathological findings were compared. Expression of CD34 for the detection of altered sinusoidal endothelium as sinusoidal capillarization and cleaved caspase-3 as an apoptosis marker were analyzed via immunohistochemistry. Survival rates were examined after 45 min of whole hepatic ischemia. RESULTS Serum aspartate aminotransferase and direct bilirubin levels were significantly decreased in the IR+milrinone group compared with those of the IR group. The degree of LI, sinusoidal capillarization and apoptosis at zone 3 in the IR group was significantly increased compared with those at the periportal zone (zone 1). These findings at zone 3 in the IR group were improved in the IR+milrinone group. SII with villus congestion and apoptosis in the IR group was significantly attenuated in the IR+milrinone group. The 7-day survival rate was significantly elevated in the IR+milrinone group as compared with that of the IR group. CONCLUSIONS A hepatic IRI model caused zone 3-based LI and SII, which were attenuated by intraportal administration of milrinone.

Possible mechanisms mediating the protective effect of cilostazol in L-arginine induced acute pancreatitis in rats: role of cGMP, cAMP, and HO-1.

Acute pancreatitis (AP) is an inflammatory disorder with a high mortality rate. Cilostazol is a selective phosphodiesterase-3 inhibitor drug that is commonly used as an antiplatelet, antithrombotic, and vasodilator drug. It exhibits antioxidant, anti-inflammatory, and anti-apoptotic activities, but its effect on AP has not been fully elucidated yet. The present study aimed to investigate the effects of cilostazol on L-arginine-induced AP and the possible protective mechanisms. A rat model of AP was established by a single i.p. injection of 3-g/kg L-arginine on day 13 of the experiment. The treated groups received a single daily oral dose of either 100 or 300 mg/kg/day for 14 consecutive days. Rats with AP showed histopathological changes of pancreatic tissue injury together with increased serum amylase enzyme activity and decreased serum insulin, pancreatic adiponectin, and cGMP levels. Moreover, AP rats showed increased pancreatic inflammatory biomarker (TNF-α, VCAM-1, and MPO) levels with decreased anti-inflammatory IL-10 levels. In addition, oxidative stress biomarkers (MDA and NO) were increased in AP with decreased antioxidant SOD activity and GSH level. Moreover, HO-1 immunostaining was increased in the AP group. Cilostazol pretreatment reversed the histopathological change; decreased the amylase activity and the levels of TNF-α, VCAM-1, and MPO; and increased the levels of insulin, adiponectin, cGMP, cAMP, and IL-10. Moreover, cilostazol decreased MDA and NO but increased SOD and GSH. Lastly, cilostazol increased the HO-1 immunostaining more than in the AP group. These data suggest that cilostazol protects against L-arginine-induced AP, which may be related to an increase in cGMP, cAMP, and upregulation of HO-1 with subsequent anti-inflammatory and antioxidant properties.

Is Milrinone Effective for Infants with Mild-to-Moderate Congenital Diaphragmatic Hernia?

OBJECTIVE: Pulmonary hypertension with left ventricular dysfunction commonly occurs in congenital diaphragmatic hernia (CDH). Milrinone, a phosphodiesterase-III inhibitor with lusitropic and vasodilator effects, is used in up to 30% of CDH infants across the United States. No randomized trials have tested the efficacy or safety of milrinone in CDH neonates. STUDY DESIGN: We performed a paired retrospective analysis of CDH infants to assess the efficacy of milrinone treatment (N = 24 pairs). Efficacy was assessed by change in oxygenation index (OI) and calculated pulmonary artery pressure (PAP). We evaluated safety on the basis of risks factors such as nonoperative bleeding, dysrhythmia, hypokalemia, and thrombocytopenia. RESULTS: The median age of milrinone initiation was 18 hours (interquartile range [IQR]: 9-38) and the median duration was 127 hours (IQR: 95-194). PAP did not change from the baseline of 49 ± 11 mm Hg (milrinone) and 53 ± 11 mm Hg (no milrinone; p = 0.327). Baseline OI was 9.6 ± 6.5. There was a similar decrease in OI (median [IQR]; milrinone: 58% [16-74]; vs. no milrinone: 65% [50-71]; p = 0.221 between groups; p < 0.005 within groups). Baseline left ventricle measurements were similar. Both groups showed significant improvement over time. No adverse events were noted. CONCLUSION: In OI-matched untreated neonates with mild-to-moderate CDH, milrinone use was associated with neither improved OI, PAP, or left ventricular measurements, nor adverse events. Study limitations warrant prospective randomized controlled trials.

Ensifentrine (RPL554): an investigational PDE3/4 inhibitor for the treatment of COPD.

Introduction: A compound that simultaneously inhibits PDE3 and PDE4 should increase airway caliber by relaxing the smooth muscle and, simultaneously, suppress airway inflammatory responses. Ensifentrine (RPL554) is considered a PDE3/4 inhibitor, although its affinity for PDE3 is 3,440 times higher than that for PDE4, that is under clinical development for the treatment of asthma and COPD and, potentially, cystic fibrosis. Areas covered: We analyze the development of this molecule from its basic pharmacology to the present clinical Phase II studies. Expert opinion: Ensifentrine is an interesting drug but there is a lack of solid studies that still does not allow us to correctly allocate this molecule in the current COPD and even asthma therapeutic armamentarium. Furthermore, apparently ensifentrine has not yet entered Phase III clinical development and, in any case, there is no reliable evidence of its ability to elicit an anti-inflammatory activity in patients with COPD or asthma. Therefore, the real anti-inflammatory profile of ensifentrine must be clarified with new studies of basic pharmacology and adequate clinical studies specifically designed. However, at present the most intriguing perspective is linked to its possible use in the treatment of cystic fibrosis, also considering the lack of valid therapeutic options for this disease.

Levosimendan ameliorates cisplatin-induced ototoxicity: Rat model.

OBJECTIVES: Cisplatin is employed for chemotherapeutic purposes in several types of adult and pediatric cancer. However, side-effects including nephrotoxicity, ototoxicity, gastrointestinal effects and neuropathy restrict the use of the drug due to their adverse impacts on quality of life. This study aimed to determine whether levosimendan exhibits a protective effect against cisplatin-related ototoxicity in a rat model by means of functional, biochemical and histochemical analysis. METHODS: The study was employed with 24 female Sprague Dawley rats. After distortion product otoacoustic emissions (DPOAE) tests applied to all rats, rats were randomly assigned into four groups of six animals each. A single intraperitoneal 15 mg/kg dose of cisplatin was administered to Cisplatin group. Levosimendan group received intraperitoneal levosimendan at a dose of 100 mg/kg for five consecutive days. Cisplatin + Levosimendan group received intraperitoneal levosimendan at a dose of 100 mg/kg for five consecutive days and a single intraperitoneal dose of 15 mg/kg cisplatin at 3rd day of the study. Control group received 8 mL/kg/day intraperitoneal saline solution for five consecutive days. The DPOAE test was repeated on the 6th day of the study. All rats were then sacrificed, the cochleas were removed and set aside for biochemical and histopathological analyses. RESULTS: A significant increase in levels of Malondialdehyde (MDA) and significantly lower activities of superoxide dismutase (SOD) and Glutathione peroxidase (GPx) were observed at rats of cisplatin group. Administration of levosimendan showed significantly lower cochlear MDA levels, while SOD and GPx activities both increased significantly. The DPOAE test performed at 6th day of the study showed a significant impairment in the signal-noise ratio (SNR) levels of rats in Cisplatin group. The SNR levels of rats treated with levosimendan were significantly higher than those of cisplatin group and were similar to those of the control group. Cisplatin impaired the cochlear structure and a severe Caspase 3 and 8-hydroxy-2' -deoxyguanosine (8-OHdG) immunopositivity was observed at cochlea of the rats of cisplatin group. Administration of levosimendan protected the structure of cochlea and there was a mild Caspase 3 and 8OHdG immunopositivity. CONCLUSION: Our data demonstrate that levosimendan protects hearing against cisplatin-induced ototoxicity and obviates cellular degeneration. It also significantly reduces oxidative stress and apoptosis, probable mechanisms involved in ototoxicity.

Comparative effects of lipid lowering, hypoglycemic, antihypertensive and antiplatelet medications on carotid artery intima-media thickness progression: a network meta-analysis.

BACKGROUND: Carotid artery intima-media thickness (cIMT) progression is a surrogate marker of atherosclerosis with a high predictive value for future CVD risk. This study evaluates the comparative efficacies of lipid lowering, hypoglycemic, antihypertensive and antiplatelet medications on cIMT progression. METHODS: We conducted a network meta-analysis (NMA) to evaluate the relative efficacies of several drug classes in modifying cIMT progression. After a literature search in several electronic databases, studies were selected by following predetermined eligibility criteria. An inverse variance-heterogeneity model was used for NMA. Sensitivity analyses were performed to check the reliability of the overall NMA, and transitivity analyses were performed to examine the effects of modifiers on the NMA outcomes. RESULTS: Data were taken from 47 studies (15,721 patients; age: 60.2 years [95% confidence interval (CI) 58.8, 61.6]; BMI: 27.2 kg/m2 [95% CI 26.4, 28.0]; and gender: 58.3% males [95% CI 48.3, 68.3]). Treatment duration was 25.8 months [95% CI 22.9, 28.7]. Of the 13 drug classes in the network, treatment with phosphodiesterase III inhibitors was the most effective in retarding annual mean cIMT against network placebo (weighted mean difference (WMD) - 0.059 mm [95% CI - 0.099, - 0.020) followed by the calcium channel blockers (WMD - 0.055 mm [95% CI - 0.099, 0.001]) and platelet adenosine diphosphate inhibitors (WMD - 0.033 mm [95% CI - 0.058, 0.008]). These 3 drug classes also attained the same positions when the NMA was conducted by using first-year changes in mean cIMT. In transitivity analyses, longer treatment duration, higher body mass index (BMI), and a higher baseline cIMT were found to be independently associated with a lesser reduction in annual mean cIMT. However, in a multivariate analysis with these 3 modifiers, none of these factors was significantly associated with annual change in mean cIMT. In the placebo group, age was inversely associated with annual change in mean cIMT independently. CONCLUSION: Phosphodiesterase III inhibitors and calcium channel blockers are found more effective than other drug classes in retarding cIMT progression. Age, BMI, and baseline cIMT may have some impact on these outcomes.

Developmental Pharmacokinetics and Age-Appropriate Dosing Design of Milrinone in Neonates and Infants with Acute Kidney Injury Following Cardiac Surgery.

BACKGROUND AND OBJECTIVE: Milrinone is used for the prevention of low cardiac output syndrome in pediatric patients after cardiac surgery. Milrinone is mainly eliminated by the kidneys; however, there is limited information on milrinone pharmacokinetics in infants who have acute kidney injury (AKI). The aim of this study was to develop a milrinone population pharmacokinetic model in neonates and infants with or without AKI. The developed milrinone pharmacokinetic model was utilized for a Monte Carlo simulation analysis to identify age-appropriate dosing regimens in neonates and infants. METHODS: Population pharmacokinetic analysis was performed with a total of 1088 serum milrinone concentrations obtained from 92 infants as part of a prospective clinical study in neonates and infants following cardiac surgery (ClinicalTrials.gov identifier NCT01966237). AKI stages were determined based on the Kidney Injury Improving Global Outcomes (KDIGO) Clinical Practice Guideline within the first three postoperative days. RESULTS: A two-compartment model was found to adequately describe the pharmacokinetic data. Allometrically scaled body weight, AKI stages, and maturation function were identified as significant predictors of milrinone clearance. The proposed dosing regimens for milrinone continuous infusions were determined based on a target concentration attainment of simulated steady-state concentration and covered three age groups across 0-12 months of age for each AKI stage. CONCLUSION: This study provides a milrinone population pharmacokinetic model in neonates and infants and captures the developmental changes in clearance. Age-appropriate dosing regimens were determined based on the simulation analysis with the developed pharmacokinetic model. The findings will facilitate model-informed precision dosing of milrinone in infants with or without AKI.

Effect of magnesium sulphate and milrinone on cerebral vasospasm after aneurysmal subarachnoid hemorrhage: a randomized study / Efeitos do sulfato de magnésio e da milrinona sobre o vasoespasmo cerebral após hemorragia subaracnoidea por aneurisma: estudo randômico

Abstract Background: Aneurysmal subarachnoid hemorrhage is an important cause of premature death and disability worldwide. Magnesium sulphate is shown to have a neuroprotective effect and it reverses cerebral vasospasm. Milrinone is also used in the treatment of cerebral vasospasm. The aim of the present study was to compare the effect of prophylactic magnesium sulphate and milrinone on the incidence of cerebral vasospasm after subarachnoid hemorrhage. Methods: The study included 90 patients with aneurysmal subarachnoid hemorrhage classified randomly (by simple randomization) into two groups: magnesium sulphate was given as an infusion of 500 mg.day-1 without loading dose for 21 days. Group B: milrinone was given as an infusion of 0.5 µg.kg-1.min-1 without loading dose for 21 days. The cerebral vasospasm was diagnosed by mean cerebral blood flow velocity in the involved cerebral artery (mean flow velocity ≥ 120 cm.s-1), neurological deterioration by Glasgow coma scale, or angiography (the decrease in diameter of the involved cerebral artery >25%). Results: The mean cerebral blood flow velocity decreased significantly in the magnesium group compared to milrinone group through Day 7, Day 14 and Day 21 (p < 0.001). The incidence of cerebral vasospasm decreased significantly with magnesium compared to milrinone (p = 0.007). The Glasgow coma scale significantly improved in the magnesium group compared to milrinone group through Day 7, Day 14 and Day 21 (p = 0.036, p = 0.012, p = 0.016, respectively). The incidence of hypotension was higher with milrinone than magnesium (p = 0.012). Conclusions: The incidence of cerebral vasospasm after aneurysmal subarachnoid hemorrhage was significantly lower and Glasgow coma scale significantly better with magnesium when compared to milrinone. Milrinone was associated with a higher incidence of hypotension and requirement for dopamine and norepinephrine when compared to magnesium.

Resumo Justificativa: A hemorragia subaracnoidea por aneurisma é uma importante causa de morte prematura e de incapacidade em todo o mundo. O sulfato de magnésio mostra um efeito neuroprotetor e reverte o vasoespasmo cerebral. A milrinona também é usada no tratamento de vasoespasmo cerebral. O objetivo do presente estudo foi comparar o efeito profilático do sulfato de magnésio e da milrinona sobre a incidência de vasoespasmo cerebral após hemorragia subaracnoidea. Métodos: O estudo incluiu 90 pacientes com hemorragia subaracnoidea por aneurisma randomicamente distribuídos (randomização simples) em dois grupos: sulfato de magnésio foi administrado em infusão de 500 mg.dia-1 sem dose de ataque durante 21 dias. O Grupo B recebeu milrinona em infusão de 0,5 µg.kg-1·min-1 sem dose de ataque durante 21 dias. O vasoespasmo cerebral foi diagnosticado pela velocidade média do fluxo sanguíneo cerebral na artéria cerebral envolvida (velocidade média do fluxo ≥ 120 cm.s-1), a deterioração neurológica por escala de coma de Glasgow ou angiografia (diminuição do diâmetro da artéria cerebral envolvida > 25%). Resultados: A velocidade média do fluxo sanguíneo cerebral diminuiu significativamente no grupo magnésio em comparação com o grupo milrinona nos dias 7, 14 e 21 (p < 0,001). A incidência de vasoespasmo cerebral diminuiu significativamente com o magnésio em comparação com milrinona (p = 0,007). A escala de coma de Glasgow melhorou significativamente no grupo magnésio em comparação com o grupo milrinona nos dias 7, 14 e 21 (p = 0,036, p = 0,012, p = 0,016, respectivamente). A incidência de hipotensão foi maior com milrinona do que com magnésio (p = 0,012). Conclusões: A incidência de vasoespasmo cerebral após hemorragia subaracnoidea por aneurisma foi significativamente menor e a escala de coma de Glasgow significativamente melhor com magnésio em comparação com milrinona. A milrinona foi associada a uma maior incidência de hipotensão e necessidade de dopamina e norepinefrina em comparação com o magnésio.

Role of Nrf2/HO-1 and PI3K/Akt Genes in the Hepatoprotective Effect of Cilostazol.

BACKGROUND: Cilostazol, a phosphodiesterase 3 inhibitor (PDE3I), is a platelet aggregation inhibitor and vasodilator that is useful for treating intermittent claudication. Experimental studies have shown that cilostazol has potent anti-inflammatory, anti-oxidant effects effects. OBJECTIVES: Although the hepatoprotective effect cilostazol has been studied, the molecular mechanisms of such protection, including: the nuclear factor-erythroid 2-related factor 2 (Nrf2) / hemoxygenase (HO-1) and the phosphoinositide 3-kinase (PI3K) /serine/threonine kinase (Akt) pathways are not fully explored, which is the aim of this study. METHODS: To achieve the aim of this study, 35 rats were grouped into: control groups, liver injury group (model- non treated: injected with thioacetamide (TAA), 150 mg/kg, i.p.), and two cilostazoltreated groups (treated with cilostazol 10 and 50 mg/kg, p.o.). The rats were treated for 8 days and injected with TAA on the 7th day of the experiment and sacrificed 48 hours after TAA injection. RESULTS: The model group showed evidence of liver injury as indicated by the elevation of liver enzymes and confirmed by histopathological findings. TAA-induced liver injury was accompanied by down-regulation of the cytoprotective pathways: PI3K/Akt and Nrf2/HO-1 mRNAs. Cilostazol administration ameliorated TAA-induced liver injury, where it caused a significant improvement in the activity of liver enzymes as well as in the histopathological changes. Such an effect was associated with a significant increase in the expression of PI3K/Akt and Nrf2/HO-1 mRNAs as detected by Real-time reverse transcription polymerase chain reaction (RT-PCR). CONCLUSION: Cilostazol protected rats against TAA hepatotoxicity through up-regulation of PI3K/Akt and Nrf2/HO-1 gene expression.

PDE3 Inhibitors Repurposed as Treatments for Age-Related Cognitive Impairment.

As the population of older individuals grows worldwide, researchers have increasingly focused their attention on identifying key molecular targets of age-related cognitive impairments, with the aim of developing possible therapeutic interventions. Two such molecules are the intracellular cyclic nucleotides, cAMP and cGMP. These second messengers mediate fundamental aspects of brain function relevant to memory, learning, and cognitive function. Consequently, phosphodiesterases (PDEs), which hydrolyze cAMP and cGMP, are promising targets for the development of cognition-enhancing drugs. Inhibitors that target PDEs work by elevating intracellular cAMP. In this review, we provide an overview of different PDE inhibitors, and then we focus on pharmacological and physiological effects of PDE3 inhibitors in the CNS and peripheral tissues. Finally, we discuss findings from experimental and preliminary clinical studies and the potential beneficial effects of the PDE3 inhibitor cilostazol on age-related cognitive impairments. In the innovation pipeline of pharmaceutical development, the antiplatelet agent cilostazol has come into the spotlight as a novel treatment for mild cognitive impairment. Overall, the repurposing of cilostazol may represent a potentially promising way to treat mild cognitive impairment, Alzheimer's disease, and vascular dementia. In this review, we present a brief summary of cAMP signaling and different PDE inhibitors, followed by a discussion of the pharmacological and physiological role of PDE3 inhibitors. In this context, we discuss the repurposing of a PDE3 inhibitor, cilostazol, as a potential treatment for age-related cognitive impairment based on recent research.

Prognostic factors of ulcer healing and amputation-free survival in patients with critical limb ischemia.

OBJECTIVE: A multidisciplinary approach is required to treat critical limb ischemia. We determined the poor prognostic factors of ischemic ulcer healing after optimal arterial revascularization, and assessed the efficacy of the medication therapy using cilostazol, which is a selective inhibitor of phosphodiesterase 3. METHODS: In this retrospective, single-center, cohort study, 129 limbs that underwent infrainguinal arterial revascularization for Rutherford class 5 critical limb ischemia were reviewed. The primary end point was the ulcer healing time after arterial revascularization. The secondary end point was the amputation-free survival rate. RESULTS: Of the 129 limbs, endovascular therapy was performed in 69 limbs, and surgical reconstructive procedures were performed in 60 limbs for initial therapy. Complete ulcer healing was achieved in 95 limbs (74%). The median ulcer healing time was 90 days. In multivariate analysis, no cilostazol use significantly inhibited ulcer healing ( p = 0.0114). A white blood cell count >10,000 ( p = 0.0185), a major defect after debridement ( p = 0.0215), and endovascular therapy ( p = 0.0308) were significant poor prognostic factors for ulcer healing. Additionally, ischemic heart disease ( p < 0.0001), albumin levels <3 g/dl ( p = 0.0016), no cilostazol use ( p = 0.0078), and a major defect after debridement ( p = 0.0208) were significant poor prognostic factors for amputation-free survival rate. CONCLUSIONS: Ulcer healing within 90 days after arterial revascularization is impaired by no cilostazol use, a white blood cell count >10,000, a major defect after debridement, and endovascular therapy. Furthermore, cilostazol improves amputation-free survival rate in patients with critical limb ischemia.

The role of platelets in acute kidney injury.

Acute kidney injury (AKI), a major public health problem associated with high mortality and increased risk of progression towards end-stage renal disease, is characterized by the activation of intra-renal haemostatic and inflammatory processes. Platelets, which are present in high numbers in the circulation and can rapidly release a broad spectrum of bioactive mediators, are important acute modulators of inflammation and haemostasis, as they are the first cells to arrive at sites of acute injury, where they interact with endothelial cells and leukocytes. Diminished control of platelet reactivity by endothelial cells and/or an increased release of platelet-activating mediators can lead to uncontrolled platelet activation in AKI. As increased platelet sequestration and increased expression levels of the markers P-selectin, thromboxane A2, CC-chemokine ligand 5 and platelet factor 4 on platelets have been reported in kidneys following AKI, platelet activation likely plays a part in AKI pathology. Results from animal models and some clinical studies highlight the potential of antiplatelet therapies in the preservation of renal function in the context of AKI, but as current strategies also affect other cell types and non-platelet-derived mediators, additional studies are required to further elucidate the extent of platelet contribution to the pathology of AKI and to determine the best therapeutic approach by which to specifically target related pathogenic pathways.

Safety of cilostazol in peripheral artery disease: a cohort from a primary healthcare electronic database.

BACKGROUND: Cilostazol has been associated with spontaneous reports of cardiovascular adverse events and serious bleeding. The objective of this study is to determine the relative risk of cardiovascular adverse events or haemorrhages in patients with peripheral artery disease treated with cilostazol in comparison to pentoxifylline users. METHODS: Population-based cohort study including all individuals older than 40 who initiated cilostazol or pentoxifylline during 2009-2011 in SIDIAP database. The two treatment groups were matched through propensity score (PS). RESULTS: Nine thousand one hundred twenty-nine patients met inclusion criteria and after PS matching, there were 2905 patients in each group. 76% of patients were men, with similar mean ages in both groups (68.8 for cilostazol and 69.4 for pentoxifylline). There were no differences in bleeding, cerebrovascular and cardiovascular events between both groups. CONCLUSIONS: Patients treated with cilostazol were different from those treated with pentoxifylline at baseline, so they were matched through PS. We did not find differences between treatment groups in the incidence of bleeding or cardiovascular and cerebrovascular events. Cilostazol should be used with precaution in elderly polymedicated patients.

The effect of cilostazol, a phosphodiesterase 3 (PDE3) inhibitor, on human hair growth with the dual promoting mechanisms.

BACKGROUND: Cilostazol, a phosphodiesterase 3 (PDE3) inhibitor, increases the intracellular level of cyclic adenosine monophosphate to cause vasodilation. Topical application of cilostazol is reported to improve local blood flow and enhance wound healing; however, its effect on human hair follicles is unknown. OBJECTIVE: The purpose of this study was to determine the effect of cilostazol on hair growth. METHODS: We investigated the expression of PDE3 in human dermal papilla cells (DPCs), outer root sheath cells (ORSCs), and hair follicles. The effects of cilostazol on DPC and ORSC proliferation were evaluated using BrdU and WST-1 assays. The expression of various growth factors in DPCs was investigated by growth factor antibody array. Additionally, hair shaft elongation was measured using ex vivo hair follicle organ cultures, and anagen induction was evaluated in C57BL/6 mice. Finally, the effects of cilostazol on vessel formation and activation of the mitogen-activated protein kinase pathway were evaluated. RESULTS: We confirmed high mRNA and protein expression of PDE3 in human DPCs. Cilostazol not only enhanced the proliferation of human DPCs but also regulated the secretion of several growth factors responsible for hair growth. Furthermore, it promoted hair shaft elongation ex vivo, with increased proliferation of matrix keratinocytes. Cilostazol also accelerated anagen induction by stimulating vessel formation and upregulating the levels of phosphorylated extracellular signal-regulated kinase, c-Jun N-terminal kinase, and P38 after its topical application in C57BL/6 mice. CONCLUSION: Our results show that cilostazol promotes hair growth and may serve as a therapeutic agent for the treatment of alopecia.