Effect of the Serotonin Blocker Sarpogrelate on Circulating Interleukin-18 Levels in Patients with Diabetes and Arteriosclerosis Obliterans

Sarpogrelate and rosuvastatin synergistically ameliorate aortic damage induced by hyperlipidemia in apolipoprotein E-deficient mice

The current study aimed to investigate whether sarpogrelate and rosuvastatin possess anti-arterial injury, and attempted to elucidate the mechanism of action underlying this activity. Sarpogrelate, a 5-hydroxytryptamine type 2A antagonist, is extensively used to prevent arterial thrombosis; however, its effects on atherosclerosis remain unknown. In the present study, sarpogrelate combined with rosuvastatin or rosuvastatin alone were administered to male ApoE^-/- mice fed a high-fat diet (HFD) for 8 weeks. Metabolic parameters in the blood samples were analyzed using an automatic analyzer. Aortic tissues were stained with hematoxylin and eosin for morphological analysis. The expression levels of oxidized-low density lipoprotein (LDL) specific scavenging receptors, lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) and cluster of differentiation 68 were detected via immunostaining. mRNA expression levels of interleukin (IL)-1β, IL-6 and tumor necrosis factor-α were determined via reverse transcription-quantitative PCR analysis, while protein expression levels of LOX-1 and phosphor(p)-ERK were determined via western blot analysis. The results demonstrated that sarpogrelate combined with rosuvastatin treatment significantly decreased total cholesterol and LDL cholesterol levels in the serum, and alleviated intimal hyperplasia and lipid deposition, accompanied by decreased inflammatory cell infiltration and lower expression levels of inflammatory cytokines, compared with rosuvastatin monotherapy or HFD treatment. Furthermore, sarpogrelate combined with rosuvastatin treatment significantly decreased the expression levels of LOX-1 and p-ERK. Taken together, these results suggest that the positive effects of sarpogrelate combined with rosuvastatin treatment on aortic injury may be associated with the regulation of the LOX-1/p-ERK signaling pathway. Sarpogrelate and rosuvastatin synergistically decreased aortic damage in ApoE^-/- HFD mice, and thus provide a basis for the treatment of aortic injury caused by hyperlipidemia with sarpogrelate.

Effects of sarpogrelate hydrochloride on peripheral arterial disease: A meta-analysis of randomized controlled trials

OBJECTIVE

The aim of our study was to assess the efficacy and safety of sarpogrelate hydrochloride by comparing the effects of sarpogrelate with conventional treatment on the improvement of symptoms in PAD patients.

METHODS

The search was conducted in PubMed, Embase, Cochrane library database, CNKI, CBM for relevant randomized controlled trials (RCTs) before January 1st, 2019. Inclusion and exclusion of studies, assessment of quality, outcome measures, data extraction and synthesis were completed by two reviewers independently. The meta-analysis was performed with RevMan 5.3.

RESULTS

Totally, 12 eligible RCTs were included in our analysis. Comparing the results of sarpogrelate group and control group, sarpogrelate significantly improved ankle-brachial index (ABI) levels (SMD = 0.05, [95%CI 0.20 to 0.74, P = .0005]), dorsalis pedis artery blood flow (MD = 0.16, [95%CI 0.09 to 0.23, P < .001]) and pain-free walking distance (PFWD) (MD = 201.86, [95%CI 9.34 to 394.38, P = .04]). The pooled analysis showed that a significant decrease in hsCRP (MD = -0.57, [95%CI -1.12 to -0.02, P = .04]) and IL-6 (MD = 1.48,[95%CI 0.39 to 2.56, P = .008]) was observed in the sarpogrelate treatment.

CONCLUSION

Sarpogrelate was effective for improving the symptoms of PAD and showed good tolerability without significant adverse events.

Effect of Long-Term Diabetes on Serotonin-Mediated Contraction in Carotid Arteries from Streptozotocin-Induced Diabetic Male and Female Rats

An accumulating body of evidence suggests that males and females differ in vascular function in arteries under pathophysiological states. In this study, we tested whether there was a sex difference associated with serotonin (5-hydroxytryptamine, 5-HT)-mediated contraction in the carotid arteries of long-term streptozotocin (STZ)-induced diabetic rats [viz. 23 or 24 weeks after STZ (65 mg/kg, intravenously (i.v.)) injection starting at 8 weeks old of rats]. In the control group, the 5-HT- and high-K⁺-induced contractions were greater in females than in males. In both sexes, treatment with STZ led to a decrease of 5-HT-induced contraction in carotid arteries compared to controls. In STZ-induced diabetic rats, the carotid arterial 5-HT-induced contraction was greater in female rats than in diabetic male rats. The high-K⁺-induced contraction was greater in diabetic female rats than in either age-matched female controls or diabetic male rats. Expression of the 5-HT_2A receptor, which is the main receptor for 5-HT-induced contraction in rat carotid arteries, was similar among the four groups. These results suggest that decreased 5-HT-induced carotid arterial contraction is seen in both sexes under long-term STZ-induced diabetic conditions. Further, this reduction seems to be weaker in females than in males. This alteration of 5-HT-induced contraction may be partly associated with increased voltage-dependent Ca²⁺ channel activity.

Efficacy and Safety of DP-R202 in Patients with Chronic Artery Occlusive Disease: Multicenter Randomized Double-blind Active-controlled Parallel Group Phase III Clinical Study

PURPOSE

Sarpogrelate hydrochloride, a selective 5-hydroxytryptamine 2A antagonist, is a widely used antiplatelet agent for the treatment of peripheral arterial disease (PAD). DP-R202 is a new sarpogrelate hydrochloride product with an improved dosage regimen compared with the agent in current use. The aim of this study was to compare the efficacy and safety profile of DP-R202 and Anplag(⁎) Tab in patients with PAD.

METHODS

This study was a 12-week, multicenter, randomized, double-blinded, active-controlled, parallel group comparative Phase III clinical trial. One hundred fifty-one volunteer patients with PAD were randomized to receive DP-R202 300 mg once daily or Anplag Table 100 mg TID for 12 weeks. The primary end point was a change in patient assessment of lower leg pain intensity with the use of a visual analog scale (VAS) after 12 weeks of treatment. Results after 4, 8, and 12 weeks of treatment were compared with baseline and between treatment groups, and all patients were assessed for adverse events (AEs), clinical laboratory data, and vital signs.

FINDINGS

Two hundred thirty-one patients from 25 medical centers were assessed, and 151 were enrolled and randomly assigned to 1 of 2 treatment groups. Seventy-five patients received DP-R202 300 mg once daily and 76 patients received Anplag Table 100 mg TID for 12 weeks. Analysis of the change in lower leg pain intensity as determined by VAS score between baseline and week 12 (mean [SD], 20.72 [20.06] mm vs 15.55 [21.44] mm) suggested that DP-R202 was not inferior to Anplag Tab, and no significant differences were found in the secondary end points. No significant between-group differences were observed in the prevalence of drug-related clinical- or laboratory-determined AEs. For tolerability, no specific issue was found during the treatment period.

IMPLICATION

The results of this study suggest that DP-R202 was not inferior to Anplag Tab for efficacy in patients with PAD and indicated a good safety profile.

Effect of sarpogrelate hydrochloride, a 5-hydroxytryptamine2 receptor antagonist, on allograft arteriosclerosis after aortic transplantation in rats

BACKGROUND

Sarpogrelate hydrochloride, a 5-hydroxytryptamine2 receptor antagonist, is known to prevent serotonin-induced neointimal hyperplasia. We examined the effect of this agent on allograft arteriosclerosis in a rat model of aortic transplantation.

METHODS

Rats were given an aortic isograft or allograft and oral administration of either saline vehicle alone or 20mg/kg daily of sarpogrelate for 8 weeks. The grafts were then harvested, and the lumen diameter and the thickness of the intima and media were measured. Comparisons were made between measurement results in isografts and allografts from rats treated and not treated with sarpogrelate. Immunohistochemistry assessments were used to detect expression of serotonin in graft specimens.

RESULTS

For both allografts and isografts, significantly less intimal thickening was observed in specimens from rats given sarpogrelate compared with rats given saline. Sarpogrelate had no effect on medial thickening in either graft type. Serotonin was detected in allografts from rats given saline alone but not in allografts from rats given sarpogrelate or in isografts.

CONCLUSIONS

Sarpogrelate hydrochloride may mitigate arteriosclerosis in allografts. Platelet aggregation and serotonin may be correlated with intimal thickening associated with chronic rejection.

Suppression of high lipid diet induced by atherosclerosis sarpogrelate

Sarpogrelate (SP), a serotonin (5-HT2A) receptor antagonist, is used as an anti-platelet agent for the treatment of some vascular diseases. SP has been reported to inhibit 5-HT induced coronary artery spasm, increase in intracellular calcium and smooth muscle cells proliferation. This study was undertaken to test that SP suppresses the development of atherosclerosis due to high cholesterol diet (HCD) by decreasing blood viscosity and oxidative stress. For this purpose, 29 rabbits were divided into four groups: control group (normal diet); normal diet group with SP at the dose of 5 mg/kg/day; HCD group fed 1% cholesterol; and HCD group with SP at the dose of 5 mg/kg/day. After 90 days of the experiment, blood samples were collected and the animals were killed; the thoracic aorta was stained by the Oil Red O staining method. The results indicate that plasma levels of cholesterol, triglycerides and malondialdehyde were increased in rabbits fed HCD. Plasma viscosity and whole blood viscosity were also higher in the HCD group than that in normal diet group. Treatment with SP prevented these alterations induced by HCD whereas this agent had no significant effect in rabbits fed normal diet. Morphological examination of the aorta revealed that SP treatment prevented the formation of foam cells and atherosclerotic plaque. It is suggested that the beneficial effects of SP in atherosclerosis may be due to actions on blood viscosity, lipid levels and oxidative stress.

Imbalance of interleukin-18 and interleukin-18 binding protein in children with Henoch-Schönlein purpura

The balance between interleukin-18 (IL-18) and its endogenous antagonist, IL-18 binding protein (IL-18BP), was evaluated in children with Henoch-Schönlein purpura (HSP). Plasma IL-18 and IL-18BP levels and peripheral blood mononuclear cell IL-18 mRNA expression were significantly higher in patients with active HSP (n = 30) than in healthy controls (n = 20); IL-18BP mRNA expression was similar in active HSP and controls. Plasma levels and mRNA expression of IL-18 and IL-18BP in patients in remission (n = 19) were similar to those in controls. The ratios of IL-18 / IL-18BP plasma levels and IL-18 / IL-18BP mRNA levels in active HSP were significantly higher than in patients in remission and healthy controls. Thus, adequate IL-18BP to block the proinflammatory activity of IL-18 may not be present in active HSP and regulation of the IL-18 / IL-18BP balance might provide a potential therapeutic strategy.

Evaluation of the effectiveness of sarpogrelate on the surrogate markers for macrovascular complications in patients with type 2 diabetes

Sarpogrelate, a selective 5-HT(2) receptor antagonist, is known to have a significant effect on antiplatelet action. This study was a double-blinded, randomized, paralleled multicenter trial to compare the effects of sarpogrelate and aspirin on preventing macrovascular complications in patients with type 2 diabetes. The subjects were randomly assigned to either the sarpogrelateor the aspirin group. The baseline parameters for macrovascular complications, such as intima media thickness (IMT), ankle-brachial index (ABI), IL-6, serotonin, adiponectin, and hsCRP, were measured before drug administration. Changes were compared at 6 and 12 months after the administration of each drug. A total of 127 subjects (63 in the sarpogrelate group and 64 in the aspirin group) were pooled during the study period. No significant differences were found in baseline IMT or in other predictors of macrovascular complications. The mean IMT increased in both groups after 12 months, but there was no significant difference between the two groups. No significant change was found in the other predictors of macrovascular complications nor in the incidence of drug-related adverse events between the two groups. During the study period, no significant differences were found between the sarpogrelate group and aspirin group in the clinical indices or in the safety of the subjects related to macrovascular complications. This suggests that sarpogrelate may be clinically useful for the primary prevention of macrovascular complications in patients with type 2 diabetes.

Mechanism of sarpogrelate action in improving cardiac function in diabetes

Although sarpogrelate, a 5-HT(2A) receptor antagonist, has been reported to exert beneficial effects in diabetes, the mechanisms of its action are not understood. In this study, diabetes was induced in rats by an injection of streptozotocin (65 mg/kg) and the animals were assessed 7 weeks later. Decreased serum insulin as well as increased serum glucose, cholesterol, and triglyceride levels in diabetic animals were associated with increased blood pressure and heart/body weight ratio. Impaired cardiac performance in diabetic animals was evident by decreased heart rate, left ventricular developed pressure, rate of pressure development, and rate of pressure decay. Treatment of diabetic animals with sarpogrelate (5 mg/kg) or insulin (10 units/kg) daily for 6 weeks attenuated the observed changes in serum insulin, glucose, and lipid levels as well as blood pressure and cardiac function by varying degrees. Protein content for membrane glucose transporters (GLUT-1 and GLUT-4) was depressed in diabetic heart; the observed alteration in GLUT-4 was partially prevented by both sarpogrelate and insulin, whereas that in GLUT-1 was attenuated by sarpogrelate only. Incubation of myoblast cells with sarpogrelate and insulin stimulated glucose uptake; these effects were additive. 5-hydroxytryptamine was found to inhibit glucose-induced insulin release from the pancreas; this effect was prevented by sarpogrelate. These results suggest that sarpogrelate may improve cardiac function in chronic diabetes by promoting the expression of membrane glucose transporters as well as by releasing insulin from the pancreas.

Assessment of binding affinity to 5-hydroxytryptamine 2A (5-HT2A) receptor and inverse agonist activity of naftidrofuryl: comparison with those of sarpogrelate

Naftidrofuryl is a peripheral vasodilator that has been clinically used in the treatment of intermittent claudication and dementia. It has 5-hydroxytryptamine 2 (5-HT(2)) antiserotonergic activity and selectively binds with the 5-HT(2) receptor. The purpose of the present study is to assess the binding affinity and functional potency of naftidrofuryl to the 5-HT(2A) receptor, to find out the inverse agonist activity of this compound at a constitutively active mutant of 5-HT(2A) receptor, and finally to compare the findings with those of sarpogrelate. The investigation showed that the binding affinity (pK(i)) of naftidrofuryl was decreased 25- or 50-fold compared to sarpogrelate in the wild-type 5-HT(2A) receptor or Cys322Lys mutant receptor, respectively. Moreover, the functional potency (pK(b)) of naftidrofuryl was much lower compared to sarpogrelate at the 5-HT(2A) receptor. In addition, inverse agonist activity of naftidrofuryl was lower compared with sarpogrelate at the constitutively active mutant receptor. Thus, the data of the present study would be very important for the clarification of interaction sites of naftidrofuryl to 5-HT(2A) receptors and also may help to understand the mechanism of inverse agonist activity at the constitutively active mutant receptor.

Impact of increased plasma serotonin levels and carotid atherosclerosis on vascular dementia

Serotonin (5-HT), a potent vasoconstrictor in the large cerebral arteries, is considered to play a key role in atherothrombosis and to be implicated in ischemic cerebrovascular events followed by delayed neuronal death. The present study aims at evaluating the relationship between plasma levels of 5-HT and vascular dementia (VaD) caused by stroke or atherosclerotic small vessel disease. Carotid artery intima-media thickness (IMT), plaques, plasma 5-HT levels and atherosclerotic parameters were determined in 20 patients with VaD and 40 age-matched controls. Age, gender, body mass index, systolic and diastolic blood pressure, fasting plasma glucose levels and serum levels of insulin, triglycerides, high-density lipoprotein cholesterol, leptin, adiponectin and interleukin-6 and plasma levels of plasminogen activator inhibitor-1 were not significantly different between the two groups. Serum levels of insulin-like growth factor-1 (IGF-1) were significantly lower in VaD patients than in controls. Plasma 5-HT levels, serum levels of hepatocyte growth factor (HGF), low-density lipoprotein (LDL) cholesterol and high-sensitive C-reactive protein (hs-CRP), max IMT and plaque frequency were significantly greater in VaD patients than in controls. There was a significant positive correlation of max IMT with 5-HT or HGF levels. Multiple logistic regression analysis revealed that increased plasma levels of 5-HT and carotid plaque prevalence had significantly independent association with VaD as compared with serum levels of IGF-1, HGF, LDL cholesterol and hs-CRP. These results suggest that increased plasma levels of 5-HT and carotid atherosclerotic plaques may be involved in the pathogenesis and progression of VaD.

Effect of Sarpogrelate, a 5-HT2A Antagonist, on Platelet Aggregation in Patients with Ischemic Stroke: Clinical-Pharmacological Dose-Response Study

BACKGROUND AND PURPOSE

It is widely accepted that antiplatelet therapy is effective for secondary prevention of atherosclerotic vascular diseases. We performed a double-blind, controlled clinical-pharmacological study to investigate the antiplatelet efficacy of sarpogrelate, a selective 5-hydroxytryptamine (5-HT(2A)) receptor antagonist, in patients with ischemic stroke, using a new assessment system employing combinations of 5-HT and epinephrine as agonists.

METHODS

Forty-seven patients with ischemic stroke were randomly assigned to three groups: 15 patients received 25 mg sarpogrelate (group L), 16 patients received 50 mg (group M), and 15 patients received 100 mg (group H) orally, three times daily for 7 days. The effect was expressed as maximum intensity of platelet aggregation on the last day of medication. Two combinations of agonists, 0.5 micromol/l 5-HT plus 3 micromol/l epinephrine, and 1 micromol/l 5-HT plus 3 micromol/l epinephrine, were used to induce platelet aggregation.

RESULTS

With both combinations of agonists, sarpogrelate treatment inhibited platelet aggregation dose-dependently (p < 0.025, Jonckheere test). In multiple-group comparison, the effect in group H was greater than that in group L or M (p < 0.025, Wilcoxon rank-sum test).

CONCLUSION

Sarpogrelate treatment inhibited platelet aggregation dose-dependently in patients with ischemic stroke, as judged by a new assessment system employing combinations of 5-HT and epinephrine as agonists.

Sarpogrelate Hydrochloride, a Selective 5-HT2A Antagonist, Improves Vascular Function in Patients With Peripheral Arterial Disease

Peripheral arterial disease (PAD) is 1 of the major manifestations of atherosclerosis. PAD is associated with endothelial dysfunction. Sarpogrelate hydrochloride, a selective 5-HT2A antagonist, has been widely used as an anti-platelet agent for the treatment of PAD. There is no information on whether endothelial function is improved after initiation of sarpogrelate treatment in patients with PAD. The purpose of this study was to evaluate the effects of sarpogrelate on endothelial function in patients with PAD. We divided PAD patients into 2 groups: those treated with sarpogrelate at a dose of 100 mg 3 times per day orally for 12 weeks (sarpogrelate group, n = 10), and those who remained on conventional therapy (control group, n = 11). Forearm blood flow (FBF) and leg blood flow (LBF) responses to reactive hyperemia (RH) and sublingual administration of nitroglycerin (NTG) were measured using strain-gauge plethysmography. After 12 weeks of sarpogrelate administration, FBF and LBF responses during RH showed significant increases from 13.2 +/- 1.7 to 18.1 +/- 2.2 mL/min per 100 mL tissue (P < 0.01) and from 8.2 +/- 0.9 to 14.2 +/- 2.1 mL/min per 100 mL tissue (P < 0.05), respectively. Sarpogrelate-induced augmentation of FBF and LBF responses to RH was maintained at 24 weeks. No change was observed in the control group at each follow-up time point. The changes in FBF and LBF after sublingual NTG were similar during follow-up periods in the 2 groups. These findings suggest that long-term oral administration of sarpogrelate improves vascular function in patients with PAD.

Serotonin acts as an up-regulator of acyl-coenzyme A:cholesterol acyltransferase-1 in human monocyte-macrophages

Acyl-coenzyme A:cholesterol acyltransferase-1 (ACAT-1) converts intracellular free cholesterol into cholesterol ester for storage in lipid droplets and plays an important role in the formation of macrophage-derived foam cells in atherosclerotic lesions. Serotonin (5-HT), a potent vasoconstrictor that is released from activated platelets, increases uptake of oxidized low-density lipoprotein (LDL) by macrophages, leading to foam cell formation, and contributes to the development of atherosclerotic plaque. However, it is not yet known whether 5-HT affects ACAT-1 expression in human monocyte-macrophages as the molecular mechanism of enhanced foam cell formation by 5-HT remains unclear. We examined the effects of 5-HT on ACAT-1 expression during differentiation of cultured human monocytes into macrophages. Expression of ACAT-1 protein but not 5-HT2A receptor increased in a time-dependent manner. 5-HT increased ACAT activity in a concentration-dependent manner after 7 days in primary monocyte culture. Immunoblotting analysis showed that 5-HT at 10 microM increased ACAT-1 protein expression level by two-fold, and this effect was abolished completely by a 5-HT2A receptor antagonist (sarpogrelate), its major metabolite (M-1), a G protein inactivator (GDP-beta-S), a protein kinase C (PKC) inhibitor (rottlerin), a Src family inhibitor (PP2), or a mitogen-activated protein kinase (MAPK) kinase inhibitor (PD98059). Northern blotting analysis indicated that among the four ACAT-1 mRNA transcripts (2.8-, 3.6-, 4.3-, and 7.0-kb), the levels of the 2.8- and 3.6-kb transcripts were selectively up-regulated by approximately 1.7-fold by 5-HT (10 microM). The results of the present study suggested that 5-HT may play a crucial role in macrophage-derived foam cell formation by up-regulating ACAT-1 expression via the 5-HT2A receptor/G protein/c-Src/PKC/MAPK pathway, contributing to the progression of atherosclerotic plaque.