Combined use of probucol and cilostazol with atorvastatin attenuates atherosclerosis in moderately hypercholesterolemic rabbits

C1QL1/CTRP14 Is Largely Dispensable for Atherosclerosis Formation in Apolipoprotein-E-Deficient Mice

The purpose of this study was to investigate the influence of C1QL1 on atherosclerosis as well as the transcriptomic alteration of the aorta. While complement C1ql-like 1 (C1QL1) is one of the C1q/tumor-necrosis-factor-related protein (CTRP) family members, also known as CTRP14, and is synthesized and secreted mainly by the brain and adipose tissues, the functional properties of the C1QL1/CTRP14 protein outside the brain and adipocytes remain, however, unknown. In this regard, apolipoprotein E (ApoE) knockout (KO) mice were fed a Western diet and injected with adenovirus (Ad) green fluorescent protein or Ad-C1QL1 through the tail vein for 12 weeks. In contrast with the control cohort, the area of atherosclerotic plaque in ApoE KO mice overexpressing C1QL1 showed no significant difference, and the RNA sequence revealed that there were only 111 differentially expressed genes (DEGs) enriched in 26 signaling pathways of the mRNA profile in the aortic atherosclerosis lesions. This analysis also revealed the expression of several genes related to metabolism, organismal system, and human diseases such as type II diabetes, which are not associated with the formation of atherosclerosis in the aorta. These findings illustrate that C1QL1 is largely dispensable for atherosclerosis formation in ApoE-deficient mice and does not improve atherosclerotic plaque formation in the aorta.

Cilostazol attenuates cardiac oxidative stress and inflammation in hypercholesterolemic rats

Atherosclerosis is a multifactorial chronic disease associated with pro-inflammatory and pro-oxidative cardiovascular states. Cilostazol, a selective phosphodiesterase 3 inhibitor (PDE3), is clinically used in the treatment of intermittent claudication and secondary prevention of cerebral infarction. The aim of this study was to evaluate the cardioprotective effects of cilostazol and the molecular mechanisms involved in hypercholesterolemic rats. Male Wistar rats were divided into four groups: control group (C) and control + cilostazol group (C+CILO), that were fed a standard chow diet, and hypercholesterolemic diet group (HCD) and HCD + cilostazol (HCD+CILO) that were fed a hypercholesterolemic diet. Cilostazol treatment started after 30 days for C+CILO and HCD+CILO groups. Animals were administered cilostazol once a day for 15 days. Subsequently, serum and left ventricles were extracted for evaluation of lipid profile, inflammatory, and oxidative biomarkers. The HCD group displayed increased serum lipid levels, inflammatory cytokines production, and cardiac NF-kB protein expression and decreased cardiac Nrf2-mediated antioxidant activity. Conversely, the cilostazol treatment improved all these cardiac deleterious effects, inhibiting NF-kB activation and subsequently decreasing inflammatory mediators, reestablishing the antioxidant properties through Nrf2-mediated pathway, including increased SOD, GPx, and catalase expression. Taken together, our results indicated that cilostazol protects hypercholesterolemia-induced cardiac damage by molecular mechanisms targeting the crosstalk between Nrf2 induction and NF-kB inhibition in the heart.

Therapeutic enzymes as non-conventional targets in cardiovascular impairments:A Comprehensive Review

Over the last few decades, substantial progress has been made towards the understanding of cardiovascular diseases (CVDs). In-depth mechanistic insights have also provided opportunities to explore novel therapeutic targets and treatment regimens to be discovered. Therapeutic enzymes are an example of such opportunities. The balanced functioning of such enzymes protects against a variety of CVDs while on the other hand, even a small shift in the normal functioning of these enzymes may lead to deleterious outcomes. Owing to the great versatility of these enzymes, inhibition and activation are key regulatory approaches to counter the onset and progression of several cardiovascular impairments. While cardiovascular remedies are already available in excess and of course they are efficacious, a comprehensive description of novel therapeutic enzymes to combat CVDs is the need of the hour. In light of this, the regulation of the functional activity of these enzymes also opens a new avenue for the treatment approaches to be employed. This review describes the importance of non-conventional enzymes as potential candidates in several cardiovascular disorders while highlighting some of the recently targeted therapeutic enzymes in CVDs.

Effect of Probucol and/or Cilostazol on Carotid Intima Media Thickness in Patients with Coronary Heart Disease: A Randomized, Multicenter, Multinational Study

Aim: In a prospective randomized multinational open blinded endpoint study, the long-term effects of probucol or probucol and cilostazol with statin on carotid mean intima media thickness (IMT) were evaluated for the first time.

Methods: Hypercholesterolemic patients with coronary artery disease were randomized to three groups and received study drugs for 3 years: the control with statin alone; the probucol group with statin and probucol; and the combo group with statin, probucol, and cilostazol. Primary efficacy endpoint was changes of mean carotid IMT at 3 years. Biomarkers, major adverse cerebro-cardiovascular events (MACCEs) and safety were secondary endpoints.

Results: Two hundred eighty-one patients were randomized into three groups. All three groups showed significant regression of carotid IMT at 3 years compared with baseline. Decrease in mean carotid IMT was significantly greater in the combo group than in the control group at 1 year. However, there were no significant differences in changes of mean carotid IMT between groups at 3 years (control; −0.12 ± 0.36 mm vs. probucol; −0.11 ± 0.32 mm vs. combo; −0.16 ± 0.38 mm). MACCEs were frequent in the control group, but the difference was not significant (control; 10.8% vs. probucol; 4.4% vs. combo; 6.9%, p = 0.35). Probucol and cilostazol were well tolerated in long-term treatment without serious drug-related adverse reactions.

Conclusion: Probucol or probucol and cilostazol with statin did not reduce carotid IMT in comparison with statin alone in this study. However, the clinical outcome of probucol-based treatment with current standard statin treatment may need further studies.

Application of a Simple Quantitative Assessment of Atherosclerotic Lesions in Freshly Isolated Aortas from Rabbits

Rabbits are widely used for the study of atherosclerosis; however, the lack of a unified and quantitative analysis of atheroma limits data interpretation and comparisons between laboratories. In this study, we applied a simple quantitative method, referred to as the oil red O (ORO) dye-eluting method, for analysis of atherosclerotic plaques in freshly isolated aortas. It employs ORO staining of the plaques followed by elution of the dye that is subjected to quantitative measurement. Atherosclerosis was induced in rabbits by feeding a 1% (w/w) high cholesterol diet for 4 or 12 weeks. Thoracic aortas were isolated and sufficiently stained by ORO. These dyes were easily and completely extracted by 100% ethanol and quantified by spectrophotometric measurement at 510 nm. A series of cross-sectional slices at 100-µm intervals were counterstained by elastic van Gieson. It was found that there was a highly positive correlation between the dye concentration and the amount of plaque tissue, determined as volume of plaques (regression coefficient r²: 0.8792, p < 0.001). The color equivalence of the dye content was expressed as µg/mm² of intimal aorta area to allow direct comparisons among aortas. The color equivalences of ORO content in rabbits fed 12 weeks were almost 5.0 times higher than those fed 4 weeks. Thus, this ORO dye-eluting method is useful for quantification of atherosclerotic plaques in aortas in rabbits, as well as other animal models.

Germinated Brown Rice Attenuates Atherosclerosis and Vascular Inflammation in Low-Density Lipoprotein Receptor-Knockout Mice

The present study investigates the impact of germinated brown rice (GBR) on atherosclerosis and the underlying mechanism in low-density lipoprotein receptor-knockout (LDLr-KO) mice. The intensity of atherosclerosis in aortas of LDLr-KO mice receiving diet supplemented with 60% GBR (weight/weight) was significantly less than that in mice fed with 60% white rice (WR) or control diet ( p < 0.05); all diets contained 0.06% cholesterol. WR or GBR diet did not significantly alter plasma total or LDL-cholesterol, fecal sterols, or glucose, or the activities of antioxidant enzymes, compared to the control diet. The adhesion of monocytes to aortas from LDLr-KO mice fed with WR diet was significantly more than that from mice receiving the control diet ( p < 0.01). GBR diet decreased monocyte adhesion to aortas compared to WR diet ( p < 0.01). GBR diet also reduced the levels of plasminogen activator inhibitor-1 (PAI-1), monocyte chemotactic protein-1 (MCP-1), and tumor necrosis factor-α (TNF-α) in plasma, and the abundances of MCP-1, PAI-1, TNF-α, intracellular cell adhesion molecule-1, toll-like receptor-4, PAI-1, LDLr-like protein, and urokinase plasminogen activator and its receptor in aortas or hearts from LDLr-KO mice in comparison to the WR diet ( p < 0.05, 0.01, respectively). The findings suggest that GBR administration attenuated atherosclerosis and vascular inflammation in LDLr-KO mice compared to WR. The anti-atherosclerotic effect of GBR in LDLr-KO mice at least in part results from its anti-inflammatory activity.

Inhibitory Effects of North American Wild Rice on Monocyte Adhesion and Inflammatory Modulators in Low-Density Lipoprotein Receptor-Knockout Mice

The present study examined the effects of wild rice on monocyte adhesion, inflammatory and fibrinolytic mediators in low-density lipoprotein receptor-knockout (LDLr-KO) mice. Male LDLr-KO mice received a cholesterol (0.06%, w/w)-supplemented diet with or without white or wild rice (60%, w/w) for 20 weeks. White rice significantly increased monocyte adhesion and abundances of monocyte chemoattractant protein-1, tissue necrosis factor-α, intracellular cell adhesion molecule-1, plasminogen activator inhibitor-1, urokinase plasminogen activator (uPA), and uPA receptor in aortae and hearts of LDLr-KO mice compared to the control diet. Wild rice inhibited monocyte adhesion to the aorta, atherosclerosis, and abundances of the inflammatory and fibrinolytic regulators in the cardiovascular tissue of LDLr-KO mice compared to white rice. White or wild rice did not significantly alter the levels of cholesterol, triglycerides, or antioxidant enzymes in plasma. The anti-atherosclerotic effect of wild rice may result from its inhibition on monocyte adhesion and inflammatory modulators in LDLr-KO mice.

Cilostazol enhances atorvastatin-induced vasodilation of female rat aorta during aging

Statins have cholesterol-independent effects including an increased vascular nitric oxide activity and are commonly used by patients with cardiovascular disease. Such patients frequently have cardiovascular diseases, which may be treated with cilostazol, a platelet aggregation inhibitor. This study was designed to investigate whether combined use of cilostazol would increase the inhibitory effect of statin on vascular smooth muscle and how maturation would affect these responses. Female Wistar rats, aged 3–4 months (young) and 14–15 months (adult), were sacrificed by cervical dislocation and the thoracic aorta was dissected and cut into 3- to 4-mm-long rings. The rings were mounted under a resting tension of 1 g in a 20-ml organ bath filled with Krebs–Henseleit solution. Rings were precontracted with phenylephrine (10−6 M), and the presence of endothelium was confirmed with acetylcholine (10−6 M). Then, the concentration–response curves were obtained for atorvastatin alone (10−10 to 3 × 10−4 M; control) and in the presence of cilostazol (10−6 M) in young and adult rat aortas. This experimental protocol was also carried out in aorta rings, which had been pretreated with NG-nitro-l-arginine methyl ester (l-NAME, 10−4 M). Atorvastatin induced concentration-dependent relaxations in young and adult rat thoracic aorta rings precontracted with phenylephrine. The pIC50 value of atorvastatin was significantly decreased in adult rat aortas. In addition, pretreatment of aortas with cilostazol enhanced the potency of atorvastatin in both young and adult aortas. Incubation with l-NAME did not completely eliminate the relaxations to atorvastatin in the presence of cilostazol. These results suggest that combined application of cilostazol with atorvastatin was significantly more potent than atorvastatin alone. Combined drug therapy may be efficacious in delaying the occurrence of cardiovascular events.

Antioxidation Effect of Simvastatin in Aorta and Hippocampus: A Rabbit Model Fed High-Cholesterol Diet

We show that hypercholesterolemia contributes to oxidative stress injury progression in brain and simvastatin counteracts the cholesterol-induced peroxidation injury in rabbit hippocampus, and we demonstrate for the first time that the simvastatin is a critical role in brain protection and identify HO-1 and other related antioxidant enzymes as molecular target for active redox compounds. Second, our experiments have pointed out an association between statin treatment and a decrease in the risk of having peroxidation damage of brain. The balance effects of simvastatin to ROS and antioxidants enzymes network are most probably due to improved SOD functional activity, increase in GSH-Px, increase in HO-1 expression, and decrease of MDA generation.