Inhibition of JAK2/STAT3/SOCS3 signaling attenuates atherosclerosis in rabbit.

BACKGROUND: Previous studies have indicated that the JAK/STAT signaling pathway is involved in modulating arterial adventitia inflammation response. In this study, we designed experiments to further investigate the effect of JAK2/STAT3/SOCS3 signaling in rabbit atherosclerosis process. METHODS: Atherosclerosis was induced in the abdominal arteries of rabbits by balloon injury of the aorta supplemented by the atherogenic diet. Simultaneously, in the process of atherosclerosis, animals underwent either ruxolitinib treatment or not for 12 weeks. At the end of the experimental period, all rabbits were sacrificed. The plaque areas in abdominal artery, the lipid burden of plaque and the calcium burden of plaque were detected by H&E staining, Oil Red O staining and Alizarin Red staining, respectively. In addition, rabbit plasma lipids and inflammatory cytokines were measured by biochemical test kits or ELISA kits. Finally, the expression and phosphorylation levels of JAK2/STAT3/SOCS3 pathway-related proteins were detected by RT-qPCR, western blot and immunohistochemistry assays. RESULTS: H&E staining and CT scan analysis showed that rabbit atherosclerosis model was constructed successfully. Ruxolitinib, an inhibitor of the Janus kinase 2 (JAK2), substantially reduced the area of atherosclerotic plaques in rabbits treated with high fat diet and balloon injury of the aorta. Moreover, ruxolitinib significantly decreased IL-6, IL-1ß, IFN-γ and TNF-α, but increased IL-10 and IL-17 levels in plasma of atherosclerotic rabbits. Additionally, ruxolitinib reduced plasma TC, TG and LDL-C contents and AIP value, while enhanced HDL-C level in atherosclerotic rabbits. Furthermore, we found that JAK2 and STAT3 phosphorylation were up-regulated in rabbits with atherosclerosis when compared with those of the control group, followed by the expression of SOCS3 was also increased due to the activation of JAK2 and STAT3. Interestingly, ruxolitinib could inactivate JAK2 and STAT3 pathway and decrease SOCS3 expression. CONCLUSION: Taken together, the inhibition of JAK2/STAT3/SOCS3 signaling pathway may be a novel method for the clinical treatment of artery atherosclerosis.

Danhong Injection Attenuates High-Fat-Induced Atherosclerosis and Macrophage Lipid Accumulation by Regulating the PI3K/AKT Insulin Pathway.

BACKGROUND AND AIMS: High-fat diet (HFD) is reported to induce atherosclerosis and insulin resistance. Macrophage lipid accumulation has been implicated as key mediators during the development of HFD-induced atherosclerosis. Traditional Chinese formula, which has long been used to improve disorder of glucose and lipid metabolism of patients, is now gradually being used as complementary therapy. This study aimed to investigate the effect of Danhong injection (DHI), a Chinese medicine used for the treatment of coronary artery disease, on atherosclerosis and its underlying mechanisms. METHODS AND RESULTS: We observed the effects of DHI on HFD-induced atherosclerosis in a mice model, macrophage lipid accumulation in an ox-LDL-stimulated macrophage model, and the role of PI3K/AKT insulin pathway in the process of DHI ameliorating atherosclerosis. The data demonstrated that DHI attenuated atherosclerosis by ameliorating blood lipids, reducing the atherosclerotic index and atherosclerotic plaque area in HFD-induced atherosclerotic mice, and inhibiting TC levels in an ox-LDL-induced macrophage model. By estimating the levels of serum insulin resistance-related indexes and protein expression of GLUT-4, DHI treatment dramatically inhibited the levels of fasting serum NEFA and fasting serum insulin and promoted the protein expression of GLUT-4 in aortas of the HFD-induced atherosclerotic mice. Moreover, according to the hints provided by microarray-based transcriptional profiling, the results demonstrated that DHI treatment also promoted the activation of PI3K/AKT insulin signaling pathway induced by IRS-1 in aortas of HFD-induced atherosclerotic mice. Furthermore, in an ox-LDL-induced macrophage model, the activation of PI3k/AKT signaling pathway also effectively functioned in the process of DHI inhibiting macrophage lipid accumulation. CONCLUSIONS: These results highlight that DHI treatment attenuates atherosclerosis and macrophage lipid accumulation by promoting the activation of PI3K/AKT insulin signaling pathway. It provides new insights into the molecular mechanism of DHI and its therapeutic potential in the treatment of atherosclerosis.

Application of ELISA Technique and Human Microsomes in the Search for 11ß-Hydroxysteroid Dehydrogenase Inhibitors.

The metabolic syndrome is defined by impaired carbohydrate metabolism and lipid disorders and often accompanied by hypertension, all of which will lead to obesity and insulin resistance. Glucocorticoids play a regulatory role in the metabolism of proteins, lipids, and carbohydrates. There is growing evidence for a role of glucocorticoids in the development of the metabolic syndrome. The most important factor that regulates the access of endogenous glucocorticoids to receptors after release of glucocorticoids and their diffusion into the cytoplasm of target cells is the steroid metabolism involving a microsomal enzyme, 11ß-hydroxysteroid dehydrogenase (11ß-HSD). The changes in intracellular glucocorticoid metabolism in the pathogenesis of obesity indicate the participation of modulation by 11ß-HSD1, which may represent a new therapeutic target for the treatment of diseases such as type 2 diabetes, visceral obesity, or atherosclerosis. The aim of our study was to determine the fast and effective method to assess inhibition activity of compounds in relation with 11ß-hydroxysteroid dehydrogenase. The material for this study was human liver and kidney microsomes. In this study we used ELISA technique using 96-well microplates coated with antibodies which were specific for analyzed enzymes. The method can quickly and efficiently measure the inhibition of both 11ß-HSD1 and 11ß-HSD2. This method can be used to search for and determine inhibitors of this enzyme. Cortisone and cortisol were used as the substrates for corresponding enzyme assays. Furthermore, 3-N-allyl-2-thiouracil derivatives were used by us for comparison purposes in developing the method, although, due to their structure, those derivatives have not previously been considered as potential inhibitors of 11ß-HSD1. 3-N-Allyl-2-thiouracil derivatives are a group worth considering, because by modifying their structure (e.g., by introducing other substituents into the pyrimidine ring) it will be possible to obtain an increase in the activity of compounds in this regard. In conclusion, this study shows an efficient and fast method of determining inhibition activity of compounds in relation with 11ß-hydroxysteroid dehydrogenase.

Baicalin alleviates atherosclerosis by relieving oxidative stress and inflammatory responses via inactivating the NF-κB and p38 MAPK signaling pathways.

Atherosclerosis (AS) is a chronic progressive disease related to inflammatory reaction. Baicalin is a flavonoid isolated from Scutellaria baicalensis georgi (Huang-qin) and exerts anti-inflammation effects in various diseases. Here, we investigated the protective effects of baicalin treatment and the potential mechanism in AS progression on AS mouse model. After ApoE-/- mice with high-lipid diets had received 12 weeks' of baicalin treatment at different concentrations, plasma lipids levels and atherosclerotic plaque areas in aorta were measured and there exhibited a prominent improvement in the baicalin treated mice compared with mice in AS model group. The expression of lipolysis related proteins (PPARα, CPT-1) was increased while the expression of adipogenesis related proteins (SREBP-1c, ACS) was decreased by baicalin treatment, indicating the anti-adipogenic effect of baicalin. Moreover, baicalin up-regulated the activities of antioxidant enzymes (SOD, CAT and GSH-Px) and down-regulated the activity of oxidative parameter MDA compared with AS model group, indicating the anti-oxidant effect of baicalin. The increased levels of pro-inflammatory cytokines (IL-6, TNF-α, sVE-cadherin) induced by AS were also decreased by baicalin treatment, indicating that baicalin acted as an anti-inflammation regulator in AS. In addition, we further explored the potential mechanism of baicalin treatment on AS, and found that baicalin treatment attenuated the high phosphorylation levels of JNK, p65, p-38 and ERK1/2 induced by AS, indicating that baicalin treatment inhibited the NF-κB and p38 MAPK signaling pathways in AS. In conclusion, baicalin treatment inhibited the NF-κB and p38 MAPK signaling pathways, thereby achieved its anti-adipogenic effect, anti-oxidant effect and anti-inflammation effect in a dose-dependent manner in AS.

Astragaloside IV inhibits Angiotensin II-stimulated proliferation of rat vascular smooth muscle cells via the regulation of CDK2 activity.

AIMS: Astragaloside IV (AS-IV) is the central active component extracted from Radix astragali, an herbal remedy widely used in traditional Chinese medicine for the treatment of cardiovascular diseases. Aberrant proliferation of vascular smooth muscle cells (VSMCs) is closely involved in the initiation and progression of cardiovascular complications, such as atherosclerosis. Here we investigated whether AS-IV inhibited agonist-induced vascular smooth muscle cells (VSMCs) proliferation and the underlying mechanism. MAIN METHODS: Quiescent cultured A10 cells (adult rat VSMCs) were treated with Angiotensin II (AngII) or AngII plus AS-IV for 48 h. The growth rate of A10 cells was analyzed by CCK8 assay. RT-PCR analysis was carried out to examine the expression of α-smooth muscle actin (α-SMA), an important phenotypic modulation marker. In addition, whether the interference of AS-IV on AngII-mediated growth of VSMCs via regulation of cell cycle was evaluated by flow cytometry. In order to explore the role of cell cycle machinery, we measured kinase activity of CDK2 by Kinase assay and the protein level of Cdc25 by western blot, respectively. KEY FINDINGS: These data suggested that AS-IV exerted beneficial effects on AngII -induced abnormal growth in rat VSMCs through disturbing cell cycle, especially block G1/S transition by attenuating CDK2 activity, which may hinder the process of pathological vascular remodeling during atherosclerosis.

Lysophosphatidylcholine Acyltransferase-3 Expression Is Associated with Atherosclerosis Progression.

Free arachidonic acid (AA) is an important precursor of lipid mediators such as leukotrienes and prostaglandins that induces inflammation and is associated with atherosclerosis progression. Recent studies have shown that lysophosphatidylcholine acyltransferase-3 (LPCAT3) converts lysophosphatidylcholine (LPC) and free AA into phosphatidylcholine (PC)-containing AA (arachidonyl-PC) and thereby can regulate intracellular free-AA levels. However, the association between LPCAT3 and atherosclerosis remains to be established. In this study, we analyzed human and mouse atherosclerotic tissues to gain insight into the arachidonyl-PC metabolism involving LPCAT3 using imaging mass spectrometry. The data revealed a complementary distribution of arachidonyl-PC and LPC in human atherosclerotic tissues with arachidonyl-PC decreasing and LPC increasing as atherosclerosis progressed. Furthermore, we found a homologous distribution of LPCAT3 expression and arachidonyl-PC based on atherosclerotic progression. In contrast, in ApoE-deficient mice, atherosclerosis increased both arachidonyl-PC accumulation and LPCAT3 expression. Taken together, these findings suggest that the regulation of LPCAT3 expression might be associated with atherosclerotic progression in humans.

Prevention of Diet-Induced Metabolic Dysregulation, Inflammation, and Atherosclerosis in Ldlr-/- Mice by Treatment With the ATP-Citrate Lyase Inhibitor Bempedoic Acid.

OBJECTIVE: Bempedoic acid (ETC-1002, 8-hydroxy-2,2,14,14-tetramethylpentadecanedioic acid) is a novel low-density lipoprotein cholesterol-lowering compound. In animals, bempedoic acid targets the liver where it inhibits cholesterol and fatty acid synthesis through inhibition of ATP-citrate lyase and through activation of AMP-activated protein kinase. In this study, we tested the hypothesis that bempedoic acid would prevent diet-induced metabolic dysregulation, inflammation, and atherosclerosis. APPROACH AND RESULTS: Ldlr-/- mice were fed a high-fat, high-cholesterol diet (42% kcal fat, 0.2% cholesterol) supplemented with bempedoic acid at 0, 3, 10 and 30 mg/kg body weight/day. Treatment for 12 weeks dose-dependently attenuated diet-induced hypercholesterolemia, hypertriglyceridemia, hyperglycemia, hyperinsulinemia, fatty liver and obesity. Compared to high-fat, high-cholesterol alone, the addition of bempedoic acid decreased plasma triglyceride (up to 64%) and cholesterol (up to 50%) concentrations, and improved glucose tolerance. Adiposity was significantly reduced with treatment. In liver, bempedoic acid prevented cholesterol and triglyceride accumulation, which was associated with increased fatty acid oxidation and reduced fatty acid synthesis. Hepatic gene expression analysis revealed that treatment significantly increased expression of genes involved in fatty acid oxidation while suppressing inflammatory gene expression. In full-length aorta, bempedoic acid markedly suppressed cholesteryl ester accumulation, attenuated the expression of proinflammatory M1 genes and attenuated the iNos/Arg1 ratio. Treatment robustly attenuated atherosclerotic lesion development in the aortic sinus by 44%, with beneficial changes in morphology, characteristic of earlier-stage lesions. CONCLUSIONS: Bempedoic acid effectively prevents plasma and tissue lipid elevations and attenuates the onset of inflammation, leading to the prevention of atherosclerotic lesion development in a mouse model of metabolic dysregulation.

Protective effects of Xiongshao Capsule () on anti-inflammatory function of high-density lipoprotein in an atherosclerosis rabbit model.

OBJECTIVE: To observe the effects of Xiongshao Capsule (, XSC) on anti-inflflammatory properties of high-density lipoprotein (HDL), myeloperoxidase (MPO) and paraoxonase 1 (PON1) in serum of atherosclerosis (AS) rabbit model and explore the anti-inflflammatory protective effects of XSC on HDL. METHODS: Sixty rabbits were randomized into the control, the model, XSC low-, medium- and high-dose (Rhizoma Chuanxiong + Radix Paeoniae rubra: 0.6+0.3, 1.2+0.6, 2.4+1.2g·kg-1·day-1, respectively), and simvastatin (1g·kg-1·day-1) groups. The model rabbits were fed with high-fat diet and drugs for 15 weeks. The blood and thoracic aortas samples were collected at the end of 15 weeks. The levels of serum MPO and PON1 as well as total cholesterol (TC) and free cholesterol (FC) in aorta wall cells were tested by enzyme linked immunosorbent assay. RESULTS: TC and FC in the model group were significantly higher than those in the control group (P<0.01). Compared with the model group, TC and FC in the XSC groups were signifificantly lower (P<0.05 or P<0.01), so was simvastatin group (P<0.01). There was no signifificant difference in PON1 level between groups (P>0.05), even between model and control groups (P>0.05). The serum MPO level in the model group was signifificantly higher than that in the control group (P<0.05), which was signifificantly lower in XSC groups as well as simvastatin group (P<0.05 or P<0.01), and no difference was found between XSC groups and simvastatin group (P>0.05). CONCLUSIONS: XSC can reduce the serum MPO level in AS rabbits to protect the anti-inflammatory function of HDL, maintaining the normal lipid transport function. TC and FC levels in aorta cells decline, and this process initiated by XSC plays an anti-AS role.

Inhibiting adhesion events by Panax notoginseng saponins and Ginsenoside Rb1 protecting arteries via activation of Nrf2 and suppression of p38 - VCAM-1 signal pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Asian countries, such as China, Japan, and Korea, have witnessed a history of more than 1000 years of Panax notoginseng (Burk.) F.H. Chen's application as a famous traditional medicine for cardiovascular diseases (Zhou et al., 2004). The use of Panax notoginseng (Sanqi) was first recorded in "Bencao Gangmu", which was written by Li Shizhen, a Chinese pharmacologist of the MING dynasty, in 1578. It is included in "The Plant List" as one species of genus Panax (family Araliaceae). Panax notoginseng saponins (PNS) are the major active ingredients extracted from Panax notoginseng. AIM OF THE STUDY: This study investigated whether PNS and the active constituent Ginsenoside Rb1 inhibits adhesion events by regulating the NF-E2-related factor 2 (Nrf2) - p38 - vascular cell adhesion molecule (VCAM)-1 pathway. MATERIALS AND METHODS: The AS model rats were treated once daily with PNS (100mg/kg, i.p.) or Rb1 (40mg/kg, i.p.), and pathological changes in the aortas were observed by electron microscopy and Sudan IV staining. The serum levels of NO, superoxide dismutase (SOD) and TNF-α were measured. Upon treatment with H2O2 to induce oxidative stress, cell viability and LDH levels were measured after cells were cultured with PNS or Rb1. oxidized low density lipoprotein (oxLDL)-induced VCAM-1 and p38 protein expression and THP1 cell adhesion to ECs were assessed after treatment with PNS or Rb1. Nuclear translocation of Nrf2 and expression of its target protein heme oxygenase (HO)-1 were observed in the respective presence of PNS or Rb1. RESULTS: Upon treatment with PNS or Rb1, pathological changes observed in the aortas of AS model rats were alleviated, and an increase in serum levels of NO and SOD and a decrease in TNF-α levels were observed. In vitro treatment with PNS or Rb1 protected endothelial cells (ECs) from H2O2-mediated cytotoxicity, suppressed oxLDL-induced p38 and VCAM-1 protein expression and inhibited THP1 cell adhesion to ECs. Finally, PNS and Rb1 treatment functionally activated Nrf2 in ECs. CONCLUSIONS: Nrf2, an EC protective system, suppresses monocyte adhesion events via the inhibition of the ROS - TNF-α - p38 - VCAM-1 pathway following treatment with PNS, with Rb1 specifically playing an important role among PNS active components.

Plasmalogen modulation attenuates atherosclerosis in ApoE- and ApoE/GPx1-deficient mice.

BACKGROUND AND AIM: We previously reported a negative association of circulating plasmalogens (phospholipids with proposed atheroprotective properties) with coronary artery disease. Plasmalogen modulation was previously demonstrated in animals but its effect on atherosclerosis was unknown. We assessed the effect of plasmalogen enrichment on atherosclerosis of murine models with differing levels of oxidative stress. METHODS AND RESULTS: Six-week old ApoE- and ApoE/glutathione peroxidase-1 (GPx1)-deficient mice were fed a high-fat diet with/without 2% batyl alcohol (precursor to plasmalogen synthesis) for 12 weeks. Mass spectrometry analysis of lipids showed that batyl alcohol supplementation to ApoE- and ApoE/GPx1-deficient mice increased the total plasmalogen levels in both plasma and heart. Oxidation of plasmalogen in the treated mice was evident from increased level of plasmalogen oxidative by-product, sn-2 lysophospholipids. Atherosclerotic plaque in the aorta was reduced by 70% (P = 5.69E-07) and 69% (P = 2.00E-04) in treated ApoE- and ApoE/GPx1-deficient mice, respectively. A 40% reduction in plaque (P = 7.74E-03) was also seen in the aortic sinus of only the treated ApoE/GPx1-deficient mice. Only the treated ApoE/GPx1-deficient mice showed a decrease in VCAM-1 staining (-28%, P = 2.43E-02) in the aortic sinus and nitrotyrosine staining (-78%, P = 5.11E-06) in the aorta. CONCLUSION: Plasmalogen enrichment via batyl alcohol supplementation attenuated atherosclerosis in ApoE- and ApoE/GPx1-deficient mice, with a greater effect in the latter group. Plasmalogen enrichment may represent a viable therapeutic strategy to prevent atherosclerosis and reduce cardiovascular disease risk, particularly under conditions of elevated oxidative stress and inflammation.

Therapeutic Potential of Ocimum tenuiflorum as MPO Inhibitor with Implications for Atherosclerosis Prevention.

Current experimental studies show that Ocimum tenuiflorum (commonly known as basil or Tulsi) possesses many health benefits. Ocimum is suggested to be antioxidative and anti-inflammatory. Eugenol, an orthomethoxyphenol, and ursolic acid have been identified as important components of basil. Myeloperoxidase (MPO), an oxidative enzyme, has been implicated in the pathogenesis of atherosclerosis. MPO-dependent oxidation of lipoproteins has been implicated in foam cell formation, dysfunctional HDL, and abnormalities in reverse cholesterol transport. Whole leaf extract of O. tenuiflorum and its major components, eugenol and ursolic acid, inhibit the oxidation of lipoproteins by myeloperoxidase/copper as measured by conjugated diene formation as well as by the thiobarbituric acid reactive substance (TBARS) assay. Whole basil leaf extract is able to attenuate the lipopolysaccharide-induced inflammation in RAW 264.7 cells compared with its components. In addition, whole basil leaf extract and eugenol inhibited MPO enzyme activity against synthetic substrates. Based on these results, we conclude that basil extract could act as an inhibitor of MPO and may serve as a nonpharmacological therapeutic agent for atherosclerosis.

Statins meditate anti-atherosclerotic action in smooth muscle cells by peroxisome proliferator-activated receptor-γ activation.

The peroxisome proliferator-activated receptor-γ (PPARγ) is an important regulator of lipid and glucose metabolism, and its activation is reported to suppress the progression of atherosclerosis. We have reported that 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) activate PPARγ in macrophages. However, it is not yet known whether statins activate PPARγ in other vascular cells. In the present study, we investigated whether statins activate PPARγ in smooth muscle cells (SMCs) and endothelial cells (ECs) and thus mediate anti-atherosclerotic effects. Human aortic SMCs (HASMCs) and human umbilical vein ECs (HUVECs) were used in this study. Fluvastatin and pitavastatin activated PPARγ in HASMCs, but not in HUVECs. Statins induced cyclooxygenase-2 (COX-2) expression in HASMCs, but not in HUVECs. Moreover, treatment with COX-2-siRNA abrogated statin-mediated PPARγ activation in HASMCs. Statins suppressed migration and proliferation of HASMCs, and inhibited lipopolysaccharide-induced expression of monocyte chemoattractant protein-1 (MCP-1) and tumor necrosis factor-α (TNF-α) in HASMCs. These effects of statins were abrogated by treatment with PPARγ-siRNA. Treatment with statins suppressed atherosclerotic lesion formation in Apoe(-/-) mice. In addition, transcriptional activity of PPARγ and CD36 expression were increased, and the expression of MCP-1 and TNF-α was decreased, in the aorta of statin-treated Apoe(-/-) mice. In conclusion, statins mediate anti-atherogenic effects through PPARγ activation in SMCs. These effects of statins on SMCs may be beneficial for the prevention of atherosclerosis.

Plasma cholesterol-lowering activity of gingerol- and shogaol-enriched extract is mediated by increasing sterol excretion.

The present study investigated the cholesterol-lowering activity of gingerol- and shogaol-enriched ginger extract (GSE). Thirty hamsters were divided into three groups and fed the control diet or one of the two experimental diets containing 0.5 and 1.0% GSE. Plasma total cholesterol, liver cholesterol, and aorta atherosclerotic plaque were dose-dependently decreased with increasing amounts of GSE added into diets. The fecal sterol analysis showed dietary GSE increased the excretion of both neutral and acidic sterols in a dose-dependent manner. GSE down-regulated the mRNA levels of intestinal Niemann-Pick C1-like 1 protein (NPC1L1), acyl CoA:cholesterol acyltransferase 2 (ACAT2), microsomal triacylglycerol transport protein (MTP), and ATP binding cassette transporter 5 (ABCG5), whereas it up-regulated hepatic cholesterol-7α-hydroxylase (CYP7A1). It was concluded that beneficial modification of the lipoprotein profile by dietary GSE was mediated by enhancing excretion of fecal cholesterol and bile acids via up-regulation of hepatic CYP7A1 and down-regulation of mRNA of intestinal NPC1L1, ACAT2, and MTP.

Onion extract (Allium cepa L.), quercetin and catechin up-regulate paraoxonase 1 activity with concomitant protection against low-density lipoprotein oxidation in male Wistar rats subjected to oxidative stress.

BACKGROUND: Paraoxonase 1 (PON1) protects the oxidative modification of low-density lipoprotein (LDL) and is a major anti-atherosclerotic protein component of high-density lipoprotein. We explored the effect of onion extract and flavonoids (quercetin and catechin) in the regulation of PON1 expression and correlating with oxidised LDL levels in male Wistar rats subjected to mercuric chloride (HgCl2) induced oxidative insult. Rats were divided into eight groups: Control, Experimental (HgCl2), Experimental + onion/catechin/quercetin, Positive control (Normal + onion/catechin/quercetin). Treatment continued for 4 weeks. RESULTS: PON1 activity and radical scavenging activity decreased in the Experimental group (P < 0.001) with increased susceptibility of LDL for oxidation and plasma malondialdehyde levels (P < 0.001). Onion extract significantly attenuated the adverse effects of HgCl2 by up-regulating PON1 activity (P < 0.05), radical scavenging activity (P < 0.01), and protected against LDL oxidation (P < 0.001) and lipid peroxidation (P < 0.01). Similar effects were observed with quercetin and to a lesser extent with catechin. CONCLUSIONS: The findings may explain the anti-atherosclerotic effect of onion and also foods containing quercetin and catechins.

In vitro screening for ß-hydroxy-ß-methylglutaryl-CoA reductase inhibitory and antioxidant activity of sequentially extracted fractions of Ficus palmata Forsk.

Hypercholesterolemia-induced oxidative stress has been strongly implicated in the pathogenesis of atherosclerosis, which is one of the major causes of mortality worldwide. The current work, for the first time, accounts the antioxidant, genoprotective, antilipoperoxidative, and HMG-CoA reductase (EC 1.1.1.34) inhibitory properties of traditional medicinal plant, Ficus palmata Forsk. Our result showed that among sequentially extracted fractions of Ficus palmata Forsk, FPBA (F. palmata bark aqueous extract) and FPLM (F. palmata leaves methanolic extract) extracts have higher phenolic content and also exhibited significantly more radical scavenging (DPPH and Superoxide) and antioxidant (FRAP) capacity. Moreover, FPBA extract also exhibited significantly higher inhibition of lipid peroxidation assay. Additionally, results showed almost complete and partial protection of oxidatively damaged DNA by these plant extracts when compared to mannitol. Furthermore, our results showed that FPBA extract (IC50 = 9.1 ± 0.61 µg/mL) exhibited noteworthy inhibition of HMG-CoA reductase activity as compared to other extracts, which might suggest its role as cardioprotective agent. In conclusion, results showed that FPBA extract not only possess significant antioxidant and genoprotective property but also is able to attenuate the enzymatic activity of HMG-CoA reductase, which might suggest its role in combating various oxidative stress-related diseases, including atherosclerosis.

Effects of simulated heat waves on ApoE-/- mice.

The effects of simulated heat waves on body weight, body temperature, and biomarkers of cardiac function in ApoE-/- mice were investigated. Heat waves were simulated in a meteorological environment simulation chamber according to data from a heat wave that occurred in July 2001 in Nanjing, China. Eighteen ApoE-/- mice were divided into control group, heat wave group, and heat wave BH4 group. Mice in the heat wave and BH4 groups were exposed to simulated heat waves in the simulation chamber. Mice in BH4 group were treated with gastric lavage with BH4 2 h prior to heat wave exposure. Results showed that the heat waves did not significantly affect body weight or ET-1 levels. However, mice in the heat wave group had significantly higher rectal temperature and NO level and lower SOD activity compared with mice in the control group (p < 0.01), indicating that heat wave had negative effects on cardiac function in ApoE-/- mice. Gastric lavage with BH4 prior to heat wave exposure significantly reduced heat wave-induced increases in rectal temperature and decreases in SOD activity. Additionally, pretreatment with BH4 further increased NO level in plasma. Collectively, these beneficial effects demonstrate that BH4 may potentially mitigate the risk of coronary heart disease in mice under heat wave exposure. These results may be useful when studying the effects of heat waves on humans.

Some salt with your statin, professor?

We know that clinical trials sponsored by the pharmaceutical industry are likely to exaggerate benefit and minimise harms. But do these biases extend to their sponsorship of non-human animal research? Using systematic review and meta-analysis Bero and colleagues show that, in the case of statins, things are a little more complicated. While the conclusions of industry-sponsored studies were indeed more enthusiastic than warranted by their data, the data themselves painted a picture more conservative than was seen in non-industry-sponsored studies. This behaviour is consistent with maximising the return on investment, seeking robust data before embarking on a clinical trial, and, once that investment has been made, making every effort to "prove" that the drug is safe and effective if this is at all credible. The findings suggest that there is something different about industry-sponsored non-human animal research, perhaps reflecting higher standards than is the case elsewhere. Perhaps the academic community can learn something from our colleagues in the commercial sector.

Nonindustry-sponsored preclinical studies on statins yield greater efficacy estimates than industry-sponsored studies: a meta-analysis.

Industry-sponsored clinical drug studies are associated with publication of outcomes that favor the sponsor, even when controlling for potential bias in the methods used. However, the influence of sponsorship bias has not been examined in preclinical animal studies. We performed a meta-analysis of preclinical statin studies to determine whether industry sponsorship is associated with either increased effect sizes of efficacy outcomes and/or risks of bias in a cohort of published preclinical statin studies. We searched Medline (January 1966-April 2012) and identified 63 studies evaluating the effects of statins on atherosclerosis outcomes in animals. Two coders independently extracted study design criteria aimed at reducing bias, results for all relevant outcomes, sponsorship source, and investigator financial ties. The I(2) statistic was used to examine heterogeneity. We calculated the standardized mean difference (SMD) for each outcome and pooled data across studies to estimate the pooled average SMD using random effects models. In a priori subgroup analyses, we assessed statin efficacy by outcome measured, sponsorship source, presence or absence of financial conflict information, use of an optimal time window for outcome assessment, accounting for all animals, inclusion criteria, blinding, and randomization. The effect of statins was significantly larger for studies sponsored by nonindustry sources (-1.99; 95% CI -2.68, -1.31) versus studies sponsored by industry (-0.73; 95% CI -1.00, -0.47) (p value<0.001). Statin efficacy did not differ by disclosure of financial conflict information, use of an optimal time window for outcome assessment, accounting for all animals, inclusion criteria, blinding, and randomization. Possible reasons for the differences between nonindustry- and industry-sponsored studies, such as selective reporting of outcomes, require further study.

Inhibition of angiotensin-1-converting enzyme activity by two varieties of ginger (Zingiber officinale) in rats fed a high cholesterol diet.

Angiotensin-1-converting enzyme (ACE) inhibitors are widely used in the treatment of cardiovascular diseases. This study sought to investigate the inhibitory effect of two varieties of ginger (Zingiber officinale) commonly consumed in Nigeria on ACE activity in rats fed a high cholesterol diet. The inhibition of ACE activity of two varieties of ginger (Z. officinale) was investigated in a high cholesterol (2%) diet fed to rats for 3 days. Feeding high cholesterol diets to rats caused a significant (P<.05) increase in the ACE activity. However, there was a significant (P<.05) inhibition of ACE activity as a result of supplementation with the ginger varieties. Rats that were fed 4% white ginger had the greatest inhibitory effect as compared with a control diet. Furthermore, there was a significant (P<.05) increase in the plasma lipid profile with a concomitant increase in malondialdehyde (MDA) content in rat liver and heart tissues. However, supplementing the diet with red and white ginger (either 2% or 4%) caused a significant (P<.05) decrease in the plasma total cholesterol, triglyceride, very low density lipoprotein-cholesterol, and low-density lipoprotein-cholesterol levels, and in MDA content in the tissues. Conversely, supplementation caused a significant (P<.05) increase in plasma high-density lipoprotein-cholesterol level when compared with the control diet. Nevertheless, rats fed 4% red ginger had the greatest reduction as compared with control diet. In conclusion, both ginger varieties exhibited anti-hypercholesterolemic properties in a high cholesterol diet fed to rats. This activity of the gingers may be attributed to its ACE inhibitory activity. However, white ginger inhibited ACE better in a high cholesterol diet fed to rats than red ginger. Therefore, both gingers could serve as good functional foods/nutraceuticals in the management/treatment of hypertension and other cardiovascular diseases.

Peptidylarginine deiminase inhibition reduces vascular damage and modulates innate immune responses in murine models of atherosclerosis.

RATIONALE: Neutrophil extracellular trap (NET) formation promotes vascular damage, thrombosis, and activation of interferon-α-producing plasmacytoid dendritic cells in diseased arteries. Peptidylarginine deiminase inhibition is a strategy that can decrease in vivo NET formation. OBJECTIVE: To test whether peptidylarginine deiminase inhibition, a novel approach to targeting arterial disease, can reduce vascular damage and inhibit innate immune responses in murine models of atherosclerosis. METHODS AND RESULTS: Apolipoprotein-E (Apoe)(-/-) mice demonstrated enhanced NET formation, developed autoantibodies to NETs, and expressed high levels of interferon-α in diseased arteries. Apoe(-/-) mice were treated for 11 weeks with daily injections of Cl-amidine, a peptidylarginine deiminase inhibitor. Peptidylarginine deiminase inhibition blocked NET formation, reduced atherosclerotic lesion area, and delayed time to carotid artery thrombosis in a photochemical injury model. Decreases in atherosclerosis burden were accompanied by reduced recruitment of netting neutrophils and macrophages to arteries, as well as by reduced arterial interferon-α expression. CONCLUSIONS: Pharmacological interventions that block NET formation can reduce atherosclerosis burden and arterial thrombosis in murine systems. These results support a role for aberrant NET formation in the pathogenesis of atherosclerosis through modulation of innate immune responses.