Exploiting the vascular protective effects of high-density lipoprotein and its apolipoproteins: an idea whose time for testing is coming, part I

Peptides as Therapeutic Agents for Atherosclerosis

More than three decades ago, as a test for the amphipathic helix theory, an 18 amino acid residue peptide and its analogs were designed with no sequence homology to any of the exchangeable apolipoproteins. Based on the apolipoprotein A-I (the major protein component of high density lipoproteins, HDL) mimicking properties, they were termed as ApoA-I mimicking peptides. Several laboratories around the world started studying such de novo-designed peptides for their antiatherogenic properties. The present chapter describes the efforts in bringing these peptides as therapeutic agents for atherosclerosis and several lipid-mediated disorders.

Regulation of Apolipoprotein A-I Gene Expression in Human Macrophages by Oxidized Low-Density Lipoprotein

Apolipoprotein A-I (ApoA-I) is a key component of reverse cholesterol transport in humans. In the previous studies, we demonstrated expression of the apoA-I gene in human monocytes and macrophages; however, little is known on the regulation of the apoA-I expression in macrophages during the uptake of modified low-density lipoprotein (LDL), which is one of the key processes in the early stages of atherogenesis leading to formation of foam cells. Here, we demonstrate a complex nature of the apoA-I regulation in human macrophages during the uptake of oxidized LDL (oxLDL). Incubation of macrophages with oxLDL induced expression of the apoA-I gene within the first 24 hours, but suppressed it after 48 h. Both effects depended on the interaction of oxLDL with the TLR4 receptor, rather than on the oxLDL uptake by the macrophages. The oxLDL-mediated downregulation of the apoA-I gene depended on the ERK1/2 and JNK cascades, as well as on the NF-κB cascade.

A homogeneous polysaccharide from Lycium barbarum: Structural characterizations, anti-obesity effects and impacts on gut microbiota

Lycium barbarum polysaccharides (LBPs) are known for their beneficial effects on diabetes, NAFLD and related chronic metabolic diseases induced by high-fat diet (HFD). However, the relevant researches are mainly about the whole crude polysaccharides, the specific active ingredient of LBPs and its bioactivity have been rarely explored. Herein, a homogeneous polysaccharide (LBP-W) was isolated and purified from crude LBPs. Structure characterizations indicated that LBP-W contained a main chain consisting of a repeated unit of →6)-β-Galp(1 → residues with branches composed of α-Araf, β-Galp and α-Rhap residues at position C-3. The objective of this study was to evaluate the anti-obesogenic effect of LBP-W and figure out the underlying mechanisms. In vivo efficacy trial illustrated that LBP-W supplements can alleviate HFD-induced mice obesity significantly. Gut microbiota analysis showed that LBP-W not only improved community diversity of intestinal flora, but also regulated their specific genera. Moreover, LBP-W can increase the content of short-chain fatty acids (SCFAs), a metabolite of the intestinal flora. In summary, all these results demonstrated that the homogeneous polysaccharide purified from L. barbarum could be used as a prebiotic agent to improve obesity by modulating the composition of intestinal flora and the metabolism of SCFAs.

Compared to serum triglyceride alone, the association between serum triglyceride to high-density lipoprotein cholesterol ratio and 10-year cardiovascular disease risk as determined by Framingham risk scores in a large Korean cohort

BACKGROUND

The incidence of cardiovascular disease (CVD) has gradually increased to the extent that it has become the most common cause of mortality worldwide, and triglyceride/high-density lipoprotein cholesterol (TG/HDL) ratio, a surrogate marker of insulin resistance, has emerged as an independent predictor of CVD. Additionally, several recent studies have reported an independent association between triglyceride-rich lipoproteins and CVD risk. The present study was conducted to investigate the association between the CVD risk determined by the Framingham risk score and the TG alone and TG/HDL ratio in a large Korean cohort.

METHODS

This cross-sectional study included 6,995 participants aged 30 to 69 years that participated in a health examination program. TG/HDL ratio quartiles and TG quartiles were categorized as follows: Q1: ≤ 1.25, Q2: 1.26-2.07, Q3: 2.08-3.48, and Q4: ≥3.49; Q1: ≤ 71, Q2: 72-105, Q3: 106-159, and Q4: ≥160, respectively. Odds ratios (ORs) and 95% confidence intervals (CI) for high Framingham 10-year CVD risk (≥10%) were calculated across TG/HDL ratio quartiles and TG quartiles using multiple logistic regression analysis after adjusting for confounding variables.

RESULTS

The mean values of most cardiometabolic variables including body mass index, blood pressure, fasting plasma glucose levels, leukocyte count, median CRP levels, and Framingham 10-year CVD risk scores increased gradually with TG/HDL ratio quartiles. The OR (95% CI) of the highest TG/HDL ratio quartile and TG quartile as compared with the lowest TG/HDL ratio quartile and TG quartile for high Framingham 10-year CVD risk was 9.27 (6.68-12.86) and 0.97 (0.69-1.36) after adjusting for confounding variables, respectively.

CONCLUSION

Compared to TG, the TG/HDL ratio was found to be positively and independently associated with Framingham 10-year CVD risk in a large Korean cohort.

OX-HDL: A Starring Role in Cardiorenal Syndrome and the Effects of Heme Oxygenase-1 Intervention

In this review, we will evaluate how high-density lipoprotein (HDL) and the reverse cholesterol transport (RCT) pathway are critical for proper cardiovascular-renal physiology. We will begin by reviewing the basic concepts of HDL cholesterol synthesis and pathway regulation, followed by cardiorenal syndrome (CRS) pathophysiology. After explaining how the HDL and RCT pathways become dysfunctional through oxidative processes, we will elaborate on the potential role of HDL dysfunction in CRS. We will then present findings on how HDL function and the inducible antioxidant gene heme oxygenase-1 (HO-1) are interconnected and how induction of HO-1 is protective against HDL dysfunction and important for the proper functioning of the cardiovascular-renal system. This will substantiate the proposal of HO-1 as a novel therapeutic target to prevent HDL dysfunction and, consequently, cardiovascular disease, renal dysfunction, and the onset of CRS.

Sex differences between Helicobacter pylori infection and cholesterol levels in an adult health checkup program

BACKGROUND

Helicobacter pylori (H pylori) infection is suggested to be a risk factor of metabolic syndrome (MS) and lipid abnormalities. The aim of this study was to investigate the influence of H pylori infection on MS and lipid abnormalities according to sex differences.

MATERIALS AND METHODS

We analyzed a total of 4551 adults who received health checkups from January 2016 to May 2017. We enrolled participants who did not have a history of hypertension, diabetes, hyperlipidemia, or cancer among those who underwent endoscopy with a rapid urease test.

RESULTS

We included a total of 1065 participants, and 663 patients (62.3%) were H pylori-positive. The H pylori infection rate was 59.3% (426/719) in males and 68.5% (237/346) in females. The mean level of total cholesterol (P = .003), low-density lipoprotein (LDL) cholesterol (P = .046), and triglycerides (P = .029) were statistically higher in H pylori-infected males. The mean level of high-density lipoprotein (HDL) cholesterol was statistically lower in H pylori-infected females (P = .032). Multivariate analysis showed that total cholesterol in males (odds ratio [OR], 1.007; 95% confidence interval [CI], 1.002-1.011) and HDL cholesterol in females (OR, 0.983; 95% CI, 0.968-0.998) were associated with active H pylori infection. The prevalence of MS was higher in both male and female H pylori-infected groups; however, there was no statistical significance.

CONCLUSIONS

H pylori infection is significantly related to increased total cholesterol in males and to decreased HDL cholesterol in females, which suggests that H pylori could affect lipid profiles and may be different by sex.

Statins for Treatment of Dyslipidemia in Chronic Kidney Disease

Dyslipidemia is a potent cardiovascular (CV) risk factor in the general population. Elevated low-density lipoprotein cholesterol (LDL-C) and/or low high-density lipoprotein (HDL-C) are well-established CV risk factors, but more precise determinants of risk include increased apoprotein B (ApoB), lipoprotein(a) [Lp(a)], intermediate and very low-density lipoprotein (IDL-C, VLDL-C; “remnant particles”), and small dense LDL particles. Lipoprotein metabolism is altered in association with declining glomerular filtration rate such that patients with non dialysis-dependent chronic kidney disease (CKD) have lower levels of HDL-C, higher triglyceride, ApoB, remnant IDL-C, remnant VLDL-C, and Lp(a), and a greater proportion of oxidized LDL-C. Similar abnormalities are prevalent in hemodialysis (HD) patients, who often manifest proatherogenic changes in LDL-C in the absence of increased levels. Patients treated with peritoneal dialysis (PD) have a similar but more severe dyslipidemia compared to HD patients due to stimulation of hepatic lipoprotein synthesis by glucose absorption from dialysate, increased insulin levels, and selective protein loss in the dialysate analogous to the nephrotic syndrome. In the dialysis-dependent CKD population, total cholesterol is directly associated with increased mortality after controlling for the presence of malnutrition–inflammation.

Treatment with statins reduces CV mortality in the general population by approximately one third, irrespective of baseline LDL-C or prior CV events. Statins have similar, if not greater, efficacy in altering the lipid profile in patients with dialysis-dependent CKD (HD and PD) compared to those with normal renal function, and are well tolerated in CKD patients at moderate doses (≤ 20 mg/day atorvastatin or simvastatin). Statins reduce C-reactive protein as well as lipid moieties such as ApoB, remnants IDL and VLDL-C, and oxidized and small dense LDL-C fraction. Large observational studies demonstrate that statin treatment is independently associated with a 30% – 50% mortality reduction in patients with dialysis-dependent CKD (similar between HD- and PD-treated patients). One recent randomized controlled trial evaluated the ability of statin treatment to reduce mortality in type II diabetics treated with HD (“4D”); the primary end point of death from cardiac cause, myocardial infarction, and stroke was not significantly reduced. However, results of this trial may not apply to other end-stage renal disease populations. Two ongoing randomized controlled trials (SHARP and AURORA) are underway evaluating the effect of statins on CV events and death in patients with CKD (including patients treated with HD and PD). Recruitment to future trials should be given a high priority by nephrologists and, until more data are available, consideration should be given to following published guidelines for the treatment of dyslipidemia in CKD. Additional consideration could be given to treating all dialysis patients felt to be at risk of CV disease (irrespective of cholesterol level), given the safety and potential efficacy of statins. This is especially relevant in patients treated with PD, given their more atherogenic lipid profile and the lack of randomized controlled trials in this population.

The protective effects of Salvia officinalis essential oil compared to simvastatin against hyperlipidemia, liver, and kidney injuries in mice submitted to a high-fat diet

The present study was undertaken to evaluate the effects of Salvia officinalis essential oil (SEO) and simvastatin in hyperlipidemic mice. Animals were randomly divided into four groups. The control group received a standard diet. The high-fat diet (HFD) group received HFD. The third and fourth groups received HFD associated either with simvastatin (2.5 mg/kg bw) or with SEO (4 mg/kg bw). All animals were sacrificed after 8 weeks of treatment. SEO and simvastatin reduced in HFD mice body weight gain, hyperlipidemia, disruption of liver and renal functions and reactive oxygen species production. In fact, total cholesterol, triglycerides, total lipids, and low-density lipoprotein cholesterol levels, as well as aspartate transaminase, alanine transaminase, gamma-glutamyltranspeptidase and lactate dehydrogenase activities were reduced, while fecal lipids increased compared to those of HFD mice. The lipid-lowering effect of SEO was more effective than that of simvastatin. PRACTICAL APPLICATIONS: High-fat diet provokes hyperlipidemia, atherosclerosis, and abnormal lipid metabolism leading to the development of hepatic and renal dysfunctions as well as perturbations of the antioxidant status in liver and kidney. The results of this research highlight the beneficial effects of SEO in the management of these disorders without inducing side effects; in fact, the plant essential oil decreased lipids and improved the antioxidant status more than did a synthetic drug.

Increased triglyceride/high-density lipoprotein cholesterol ratio may be associated with reduction in the low-density lipoprotein particle size: assessment of atherosclerotic cardiovascular disease risk

Hypertriglyceridemia, which often leads to both low-density lipoprotein (LDL) and high-density lipoprotein (HDL) metabolic disorders, is a strong risk factor for the development of atherosclerotic cardiovascular disease (ASCVD). We hypothesized that the triglyceride (TG)/HDL cholesterol (TG/HDL-C) ratio may be more useful for estimation of the LDL-particle size, as a well-known risk factor for ASCVD, as compared to the serum TG level per se. Polyacrylamide gel electrophoresis was used in this study to estimate the LDL-particle size [relative LDL migration (LDL-Rm value)] in 649 consecutive patients with one additional risk factor for ASCVD. Multivariable regression analysis identified both serum TG (β = 0.556, p < 0.0001) and the serum TG/HDL-C ratio (β = 0.607, p < 0.0001) as independent indicators of the LDL-particle size. In terms of evaluation of the accuracy of indicators of LDL-Rm values equal to or greater than 0.40, which are suggestive of the presence of large amounts of small-dense LDL and represent the upper limit (mean + 2 standard deviation) of the normal range in this population, both the serum TG level and serum TG/HDL-C ratio showed high accurate areas under the receiver-operating characteristic curve (0.900 vs. 0.914), but with a negative likelihood ratio of 0.506 vs. 0.039, indicating that the TG/HDL-C ratio model is superior for excluding patients with values below the cutoff value and with LDL-Rm values ≥ 0.40. Furthermore, in 456 patients followed up for at least 1 year, multivariable regression analysis identified increased serum TG/HDL-C ratio as an independent predictor of a decreased LDL-particle size. These results suggest that the serum TG/HDL-C ratio may be more useful for assessing the risk of ASCVD as compared to the serum TG level per se. To reduce the risk of ASCVD, it may be important to focus not only on changes of the serum LDL-C, but also on those of the serum TG/HDL-C ratio.

Phytochemical Screening and Antidiabetic, Antihyperlipidemic, and Antioxidant Properties of Anthyllis henoniana (Coss.) Flowers Extracts in an Alloxan-Induced Rats Model of Diabetes

Background

This study investigates the biological activities of Anthyllis henoniana flowers extracts.

Materials and Methods

Antioxidant activity and the in vitro inhibitory effect of key digesting enzymes related to postprandial hyperglycemia were determined. Diabetic rats were orally and daily given the best extract from flowers of Anthyllis henoniana at a dose of acarbose for one month.

Results

Among the extracts, the ethyl acetate one displayed remarkable antioxidant activity including DPPH (IC₅₀ = 2.34 mg/mL) and was more effective in inhibiting α-glucosidase (IC₅₀ = 17 μg/mL) than α-amylase (IC₅₀ = 920 μg /mL) activities. In vivo, the results proved that ethyl acetate extract at doses of 400 mg/kg bw decreased significantly the blood glucose level and lipid profile levels and increased the activities of antioxidant enzymes. These protective impacts of Anthyllis henoniana ethyl acetate flowers extract were confirmed by histological results.

Conclusion

This study demonstrates, for the first time, that Anthyllis henoniana flowers ethyl acetate extract is effective in inhibiting hyperglycemia and oxidative stress caused by diabetes.

APOA-1Milano muteins, orally delivered via genetically modified rice, show anti-atherogenic and anti-inflammatory properties in vitro and in Apoe-/- atherosclerotic mice

BACKGROUND

Atherosclerosis is a slowly progressing, chronic multifactorial disease characterized by the accumulation of lipids, inflammatory cells, and fibrous tissue that drives to the formation of asymmetric focal thickenings in the tunica intima of large and mid-sized arteries. Despite the high therapeutic potential of ApoA-1 proteins, the purification and delivery into the disordered organisms of these drugs is still limited by low efficiency in these processes.

METHODS AND RESULTS

We report here a novel production and delivery system of anti-atherogenic APOA-1Milano muteins (APOA-1M) by means of genetically modified rice plants. APOA-1M, delivered as protein extracts from transgenic rice seeds, significantly reduced macrophage activation and foam cell formation in vitro in oxLDL-loaded THP-1 model. The APOA-1M delivery method and therapeutic efficacy was tested in healthy mice and in Apoe^-/- mice fed with high cholesterol diet (Western Diet, WD). APOA-1M rice milk significantly reduced atherosclerotic plaque size and lipids composition in aortic sinus and aortic arch of WD-fed Apoe^-/- mice as compared to wild type rice milk-treated, WD-fed Apoe^-/- mice. APOA-1M rice milk also significantly reduced macrophage number in liver of WD-fed Apoe^-/- mice as compared to WT rice milk treated mice.

TRANSLATIONAL IMPACT

The delivery of therapeutic APOA-1M full length proteins via oral administration of rice seeds protein extracts (the 'rice milk') to the disordered organism, without any need of purification, might overcome the main APOA1-based therapies' limitations and improve the use of this molecules as therapeutic agents for cardiovascular patients.

Hippophae rhamnoides as novel phytogenic feed additive for broiler chickens at high altitude cold desert

Extremes of climate and hypobaric hypoxia cause poor growth performance in broiler chickens at high altitude. The present study examined the potential of Hippophae rhamnoides extract as phytogenic feed additive for broilers reared at 3500 m above mean sea level (MSL). Higher content of phytomolecules were recorded during characterization of the extract. Immunomodulatory activity of extract was observed in chicken lymphocytes through in-vitro studies. Thereafter, for in vivo study, 105 day old Rhode Island Red (RIR) Cross-bred chicks were randomly distributed in to control and treatments T1, T2, T3, T4, T5, and T6 which were supplemented with H. rhamnoides aqueous extract along with basal diet, at level of 100, 150, 200, 300, 400, and 800 mg/kg body weight of chicken, respectively. Among the experimental groups, birds in the T3 group represent the highest body weight. Furthermore, treatment group birds had shown better physio-biochemical indices as compared to control group birds. Interestingly, lower mortality rate due to ascites and coccidiosis was recorded in treatment groups and therefore, higher net return was observed. Hence, present investigation demonstrated the beneficial effect of H. rhamnoides extract (@200 mg/kg) at high altitude and therefore, may be used in formulation of feed additive for poultry ration.

Heart Transplantation and Risk of Cardiac Vasculopathy Development: What Factors Are Important?

BACKGROUND The aim of this study was to find the main risk factors for development of cardiac allograft vasculopathy (CAV), especially factors identified before the surgical procedure and factors related to the recipient profile and the medical history of the donor. MATERIAL AND METHODS There were 147 patients who had heart transplantation (HT) included in this study: mean age was 45.8±15.3 years. All study patients had coronary angiography after HT. Analyzed risk factors were: non-immunologic recipient risk factors (age of transplantation, smoking, hypertension, lipids, diabetes, obesity and weight gain after HT), immunologic recipient risk factors (acute cellular rejection (ACR), acute humoral rejection (AMR), cytomegalovirus (CMV) episodes), and donor-related risk factors (age, sex, catecholamine usage, ischemic time, compatibility of sex and blood groups, cause of death, cardiac arrest). RESULTS CAV was recognized in 48 patients (CAV group); mean age 53.6±13.6 years. There were 99 patients without CAV (nonCAV group); mean age 48.3±15.5 years. A univariate Cox analysis of the development of coronary disease showed statistical significance (p<0.05) for baseline high-density lipid (HDL), ACR, AMR, CMV, and donor age. Multivariate Cox regression model confirmed that only baseline HDL, episodes of ACR, donor age, and CMV infection are significant for the frequency of CAV after HT. CONCLUSIONS Older donor age is highly associated with CAV development. Older donor age and low level of HDL in heart recipients with the strongest influence of immunologic risk factors (ACR, CMV infection) were linked with development of CAV.

The Relationship between the Triglyceride to High-Density Lipoprotein Cholesterol Ratio and Metabolic Syndrome

BACKGROUND

Metabolic syndrome is associated with cardiovascular diseases and is characterized by insulin resistance. Recent studies suggest that the triglyceride/high-density lipoprotein cholesterol (TG/HDLC) ratio predicts insulin resistance better than individual lipid levels, including TG, total cholesterol, low-density lipoprotein cholesterol (LDLC), or HDLC. We aimed to elucidate the relationship between the TG/HDLC ratio and metabolic syndrome in the general Korean population.

METHODS

We evaluated the data of adults ≥20 years old who were enrolled in the Korean National Health and Nutrition Examination Survey in 2013 and 2014. Subjects with angina pectoris, myocardial infarction, stroke, or cancer were excluded. Metabolic syndrome was defined by the harmonized definition. We examined the odds ratios (ORs) of metabolic syndrome according to TG/HDLC ratio quartiles using logistic regression analysis (SAS ver. 9.4; SAS Institute Inc., Cary, NC, USA). Weighted complex sample analysis was also conducted.

RESULTS

We found a significant association between the TG/HDLC ratio and metabolic syndrome. The cutoff value of the TG/HDLC ratio for the fourth quartile was ≥3.52. After adjustment, the OR for metabolic syndrome in the fourth quartile compared with that of the first quartile was 29.65 in men and 20.60 in women (P<0.001).

CONCLUSION

The TG/HDLC ratio is significantly associated with metabolic syndrome.

Differential expression of osteopontin, and osteoprotegerin mRNA in epicardial adipose tissue between patients with severe coronary artery disease and aortic valvular stenosis: association with HDL subclasses

BACKGROUND

Previous studies suggest a relationship of the epicardial adipose tissue (EAT) with progression and calcification of the atherosclerotic plaque; however, it is unknown if this tissue expresses genes that may participate on these processes and if the expression of these genes is regulated by high-density lipoprotein (HDL) subclasses.

METHODS

To explore this possibility, we determined the mRNA expression by qPCR of a pro-calcifying gene (osteopontin (OPN)), and two anti-calcifying genes (osteoprotegerin (OPG) and osteonectin (ON)), in biopsies of EAT obtained from 15 patients with coronary artery disease (CAD) determined by angiography, and 15 patients with diagnostic of aortic valve stenosis but without CAD as control group. We determined the distribution and composition of HDL subclasses by electrophoresis and their statistical relationship with the gene expression in EAT.

RESULTS

EAT from CAD patients showed a higher expression level of OPN and OPG than control group, whereas ON expression was similar between groups. Large HDL subclasses were cholesterol-poor in CAD patients as estimated by the cholesterol-to-phospholipid ratio. A linear regression model showed an independent association of OPN expression with HDL3a-cholesterol, and OPG expression with the relative proportion of HDL3b protein. Logistic analysis determined that OPN expression was positively associated with the presence of atherosclerotic plaque CONCLUSION: OPN, ON, and OPG genes are transcribed in EAT; to the exception of ON, the level of expression was different in CAD patients and control group, and correlated with some HDL subclasses, suggesting a new role of these lipoproteins.

Associations of Cholesteryl Ester Transfer Protein TaqIB Polymorphism with the Composite Ischemic Cardiovascular Disease Risk and HDL-C Concentrations: A Meta-Analysis

BACKGROUND

Previous studies have evaluated the associations between the cholesteryl ester transfer protein (CETP) TaqIB polymorphism (rs708272), the risk of developing composite ischemic cardiovascular disease (CVD) and the concentration of high-density lipoprotein cholesterol (HDL-C), but results remain controversial. The objective of this study was to investigate whether a relationship exists between these factors.

METHODS

We conducted a meta-analysis of available studies to clarify the associations of the CETP TaqIB polymorphism with HDL-C concentration and the composite ischemic CVD risk in both Asians and Caucasians. All statistical analyses were done with Stata 12.0.

RESULTS

Through utilization of the Cochrane Library, Embase, PubMed, Web of Science, Springer, China Science and Technology Journal Database, China National Knowledge Infrastructure, Google Scholar, and Baidu Library, a total of 45 studies from 44 papers with 20,866 cases and 21,298 controls were combined showing a significant association between the CETP TaqIB variant and composite ischemic CVD risk. Carriers of allele TaqIB-B1 were found to have a higher risk of composite ischemic CVD than non-carriers: OR = 1.15, 95% CI = 1.09-1.21, p < 0.001. Meanwhile, 28 studies with 23,959 subjects were included in the association between the CETP TaqIB polymorphism and the concentration of HDL-C. RESULTS suggested that carriers of the B1B1 genotype had lower concentrations of HDL-C than those of the B2B2 genotype: SMD = 0.50, 95% CI = 0.36-0.65, p < 0.001.

CONCLUSIONS

The synthesis of available evidence demonstrates that the CETP TaqIB polymorphism protects against composite ischemic CVD risk and is associated with a higher HDL-C concentration in both Asians and Caucasians.

Early-onset peripheral arterial occlusive disease: clinical features and determinants of disease severity and location

Early-onset peripheral lower extremity arterial occlusive disease (PAD) is an uncommon, poorly characterized manifestation of atherosclerotic vascular disease. We studied the clinical presentation and correlates of disease severity and location in patients with early-onset PAD identifi ed at non-invasive arterial evaluation. We identifi ed a series of 159 patients who were younger than 50 years and had an abnormal resting or postexercise ankle brachial index (ABI) (<0.9) or, if arteries were noncompressible, monophasic arterial Doppler signals. Disease severity and location were determined based on results of noninvasive vascular laboratory testing. Presence of coexisting atherosclerosis in other arterial beds was ascertained by review of patient records. Multivariable logistic regression analyses were used to identify risk factors associated with disease severity and location. Mean age of the patients was 42.7 6 4.2 years and 55% were women. Prevalence of risk factors was 76% for current or past smoking; 71%, dyslipidemia; 53%, hypertension; 35%, diabetes; and 53%, family history. Claudication was present in 50%, rest pain in 3%, ulceration in 31% and the remaining 16% did not have symptoms from PAD. Low high-density lipoprotein (HDL)-cholesterol and female sex were associated with severity. Of 102 patients in whom disease location could be determined noninvasively, 65% had aortoiliac disease. Female sex, low HDL-cholesterol, and absence of diabetes were associated with aortoiliac disease. Atherosclerosis in other arterial beds was identifi ed in 53% of the patients. Conclusion: In this study population of early-onset atherosclerotic PAD, men and women were equally represented. The disease involved predominantly the aortoiliac location. Low HDL-cholesterol and female sex were associated with disease severity. An aggressive approach to diagnosis and treatment may be warranted as atherosclerosis in other arterial beds was prevalent in half of the patients.

High-density lipoprotein cholesterol (HDL-C) in cardiovascular disease: effect of exercise training

Decreases in high-density lipoprotein cholesterol (HDL-C) levels are associated with an increased risk of coronary artery disease (CAD), whereas increased HDL-C levels are related to a decreased risk of CAD and myocardial infarction. Although HDL prevents the oxidation of low-density lipoprotein under normal conditions, it triggers a structural change, inhibiting antiarteriosclerotic and anti-inflammatory functions, under pathological conditions such as oxidative stress, inflammation, and diabetes. HDL can transform into various structures based on the quantitative reduction and deformation of apolipoprotein A1 and is the primary cause of increased levels of dysfunctional HDL, which can lead to an increased risk of CAD. Therefore, analyzing the structure and components of HDL rather than HDL-C after the application of an exercise training program may be useful for understanding the effects of HDL.

High-density lipoprotein, mitochondrial dysfunction and cell survival mechanisms

Ischemic injury is associated with acute myocardial infarction, percutaneous coronary intervention, coronary artery bypass grafting and open heart surgery. The timely re-establishment of blood flow is critical in order to minimize cardiac complications. Reperfusion after a prolonged ischemic period, however, can induce severe cardiomyocyte dysfunction with mitochondria serving as a major target of ischemia/reperfusion (I/R) injury. An increase in the formation of reactive oxygen species (ROS) induces damage to mitochondrial respiratory complexes leading to uncoupling of oxidative phosphorylation. Mitochondrial membrane perturbations also contribute to calcium overload, opening of the mitochondrial permeability transition pore (mPTP) and the release of apoptotic mediators into the cytoplasm. Clinical and experimental studies show that ischemic preconditioning (ICPRE) and postconditioning (ICPOST) attenuate mitochondrial injury and improve cardiac function in the context of I/R injury. This is achieved by the activation of two principal cell survival cascades: 1) the Reperfusion Injury Salvage Kinase (RISK) pathway; and 2) the Survivor Activating Factor Enhancement (SAFE) pathway. Recent data suggest that high density lipoprotein (HDL) mimics the effects of conditioning protocols and attenuates myocardial I/R injury via activation of the RISK and SAFE signaling cascades. In this review, we discuss the roles of apolipoproteinA-I (apoA-I), the major protein constituent of HDL, and sphingosine 1-phosphate (S1P), a lysosphingolipid associated with small, dense HDL particles as mediators of cardiomyocyte survival. Both apoA-I and S1P exert an infarct-sparing effect by preventing ROS-dependent injury and inhibiting the opening of the mPTP.

Lack of Association between High-Density Lipoprotein Cholesterol and Angiographic Coronary Lesion Severity in Chinese Patients with Low Background Low-Density Lipoprotein Cholesterol

BACKGROUND

The atheroprotective role of high-density lipoprotein (HDL-C) particles as measured by HDL-C level in coronary arterial disease (CAD) remains unsettled. The aim of our study was to ascertain whether HDL-C was associated with the development and severity of coronary artery disease in Chinese patients who underwent coronary angiogram with low background Low-density lipoprotein (LDL-C) levels, which has not been previously investigated.

METHODS

Between March 1995 and May 2000, 566 consecutive patients (408 males, 66.7 ± 11.3 years of age) with background LDL-C less than 100 mg/dl who underwent coronary artery angiography at our cath lab for suspected CAD were retrospectively recruited into the study. The severity of coronary lesions was measured by conventional coronary angiography and modified Gensini scores.

RESULTS

In those subjects with significant coronary lesions, there were more males and conventional CAD risk factors of diabetes mellitus, smoking, and chronic renal disease. They were also older compared to those in the control group. However, total cholesterol, LDL-C, HDL-C, triglyceride levels and use of statins were similar in both groups. In those subjects with significant coronary lesions, there was no difference in conventional coronary lesion severity or modified Gensini score between the quartered HDL-C subgroups. Furthermore, there was no significant correlation between serum HDL-C level and modified Gensini scores. In linear regression analysis, HDL-C was not an independent predictor for modified Gensini scores. Furthermore, HDL-C was also not an independent risk factor for the presence of significant coronary lesions in low LDL-C patients in logistic regression analysis.

CONCLUSIONS

In Chinese patients with low background LDL-C, serum HDL-C was not associated with development of CAD or lesion severity in patients with suspected CAD. Therefore, HDL-C did not appear to be atheroprotective in these patients.

KEY WORDS

Coronary artery disease; Gensini score; High-density lipoprotein cholesterol.

Interactions of Six SNPs in ABCA1gene and Obesity in Low HDL-C Disease in Kazakh of China

Objective: To detect the interactions between six functional polymorphisms in ABCA1 and obesity in Kazakhs with low HDL-C levels. Methods: A total of 204 patients with low HDL-C and 207 health control subjects, which were randomly selected from among 5692 adult Kazakhs, were matched for age and sex. We genotyped ABCA1 single nucleotide polymorphisms of rs2515602, rs3890182, rs2275542, rs2230806, rs1800976, and rs4149313. Results: (1) The genotypic and allelic frequencies of rs2515602, rs2230806 and rs4149313 were different between normal HDL-C and low HDL-C subjects, the genotypic frequency of rs2275542 was also different between normal HDL-C and low HDL-C subjects (p < 0.05); (2) the level of HDL-C (rs2515602 and rs2275542) in normal HDL-C subjects were different among the genotypes (p < 0.05); the levels of TC, LDL-C (rs2515602, rs4149313); TG (rs2515602, rs1800976, rs4149313) in low HDL-C patients were different among the genotypes (p < 0.05); (3) interactions between the rs3890182, rs2275542, rs180096, and rs4149313 polymorphisms in ABCA1 gene and obesity may be associated with low HDL-C disease; (4) the C-C-C-A-A-G, T-C-C-A-A-A, T-C-C-A-A-G, C-C-C-A-A-A, C-T-G-G-A-A, and T-T-C-G-A-A haplotypes were significant between the subjects with normal HDL-C and low HDL-C level (p < 0.05). Conclusions: The differences in serum lipid levels between normal HDL-C and low HDL-C subjects among Kazakhs might partly result from ABCA1 gene polymorphisms; ABCA1 gene polymorphisms may be associated with low HDL-C disease; the low HDL-C disease might partly result from interactions between ABCA1 gene polymorphisms and obesity; the C-C-C-A-A-G, T-C-C-A-A-A, and T-C-C-A-A-G haplotypes may serve as risk factors of low HDL-C disease among Kazakhs, the C-C-C-A-A-A, C-T-G-G-A-A, and T-T-C-G-A-A haplotypes may serve as protective factor of low HDL-C disease among Kazakhs.

HDL/ApoA-1 infusion and ApoA-1 gene therapy in atherosclerosis

The HDL hypothesis stating that simply raising HDL cholesterol (HDL-C) may produce cardiovascular benefits has been questioned recently based on several randomized clinical trials using CETP inhibitors or niacin to raise HDL-C levels. However, extensive pre-clinical data support the vascular protective effects of administration of exogenous ApoA-1 containing preβ-HDL like particles. Several small proof-of-concept clinical trials using such HDL/ApoA-1 infusion therapy have shown encouraging results but definitive proof of efficacy must await large scale clinical trials. In addition to HDL infusion therapy an alternative way to exploit beneficial cardiovascular effects of HDL/ApoA-1 is to use gene transfer. Preclinical studies have shown evidence of benefit using this approach; however clinical validation is yet lacking. This review summarizes our current knowledge of the aforementioned strategies.

Effect of aerobic exercise on risk factors of cardiovascular disease and the apolipoprotein B / apolipoprotein a-1 ratio in obese woman

[Purpose] The objective of this study was to confirm whether consistent aerobic exercise has an effect on the apolipoprotein B/apolipoprotein A-1 ratio or reduces the risk of cardiovascular disease in obese women. [Subjects and Methods] The participants included 32 obese women between the ages of 40 and 49. Subjects were randomly divided into two groups (n = 16 in each group): the control group and the exercise group. The exercise program in this study corresponded to an intensity of 50 to 60% of the maximum volume of minute oxygen consumption and was performed three times per week over 12 weeks. Physical measurements, measurement of cardiorespiratory fitness and blood pressure, and blood collection were done before and after the 12 weeks of exercise at the same time and under the same conditions. [Results] Based on the results of this study, there were significant interaction effects in both time and group weight, for body mass index, percent body fat, maximum volume of minute oxygen consumption, high-density lipoprotein cholesterol, and the apolipoprotein B/apolipoprotein A-1 ratio. Moreover, waist circumference, total cholesterol, and the atherogenic index decreased significantly after 12 weeks of aerobic exercise. [Conclusion] Regular aerobic exercise effectively improved cardiovascular risk factors and decreased the obesity index in obese women.

Effects of anacetrapib on plasma lipids in specific patient subgroups in the DEFINE (Determining the Efficacy and Tolerability of CETP INhibition with AnacEtrapib) trial

BACKGROUND

In the Determining the Efficacy and Tolerability of cholesteryl ester transfer protein (CETP) INhibition with AnacEtrapib (DEFINE) trial, anacetrapib added to statin produced robust low-density lipoprotein cholesterol (LDL-C)-lowering and high-density lipoprotein cholesterol (HDL-C)-raising vs placebo in patients with coronary heart disease (CHD). Predictors of the degree of LDL-C and HDL-C responses to anacetrapib, however, are poorly understood.

OBJECTIVE

Lipid effects of anacetrapib in patient subgroups within the DEFINE trial (clinicaltrials.gov: NCT00685776) are reported.

METHODS

The percent of placebo-corrected changes from baseline for LDL-C (estimated by Friedewald calculation [Fc-LDL-C]) and HDL-C after 24 weeks of anacetrapib 100 mg/day were compared among patients by age, gender, race, diabetes status, type of concomitant statin with or without other lipid therapies, and baseline HDL-C, Fc-LDL-C, and triglyceride (TG) levels.

RESULTS

Percent decreases in Fc-LDL-C and increases in HDL-C with anacetrapib were similar (magnitude of difference generally <1/5 of the overall treatment effect) across subgroups by age, gender, diabetes status, lipid-modifying regimen, and baseline Fc-LDL-C, HDL-C, or TG. On the other hand, anacetrapib effects on Fc-LDL-C (-24% vs -41%) and HDL-C (+75% vs +139%) appeared to be less in black vs white patients, respectively.

CONCLUSION

Effects of anacetrapib on Fc-LDL-C and HDL-C were generally comparable across subgroups, including being relatively independent of baseline Fc-LDL-C, HDL-C, or TG levels. The clinical impact of the lipid-modifying effects of anacetrapib is being evaluated in the cardiovascular disease outcomes trial, Randomized EValuation of the Effects of Anacetrapib though Lipid-modification (REVEAL).

Portulaca oleracea reduces triglyceridemia, cholesterolemia, and improves lecithin: cholesterol acyltransferase activity in rats fed enriched-cholesterol diet

PURPOSE

The effects of Portulaca oleracea (Po) lyophilized aqueous extract were determined on the serum high-density lipoproteins (HDL2 and HDL3) amounts and composition, as well as on lecithin: cholesterol acyltansferase (LCAT) activity.

METHODS

Male Wistar rats (n = 12) were fed on 1% cholesterol-enriched diet for 10 days. After this phase, hypercholesterolemic rats (HC) were divided into two groups fed the same diet supplemented or not with Portulaca oleracea (Po-HC) (0.5%) for four weeks.

RESULTS

Serum total cholesterol (TC) and triacylglycerols (TG), and liver TG values were respectively 1.6-, 1.8-, and 1.6-fold lower in Po-HC than in HC group. Cholesterol concentrations in LDL-HDL1, HDL2, and HDL3 were respectively 1.8, 1.4-, and 2.4-fold decreased in Po-HC group. HDL2 and HDL3 amounts, which were the sum of apolipoproteins (apos), TG, cholesteryl esters (CE), unesterified cholesterol (UC), and phospholipids (PL) contents, were respectively 4.5-fold higher and 1.2-fold lower with Po treatment. Indeed, enhanced LCAT activity (1.2-fold), its cofactor-activator apo A-I (2-fold) and its reaction product HDL2-CE (2.1-fold) were observed, whereas HDL3-PL (enzyme substrate) and HDL3-UC (acyl group acceptor) were 1.2- and 2.4-fold lower.

CONCLUSION

Portulaca oleracea reduces triglyceridemia, cholesterolemia, and improves reverse cholesterol transport in rat fed enriched-cholesterol diet, contributing to anti-atherogenic effects.

Effect on cardiovascular risk of high density lipoprotein targeted drug treatments niacin, fibrates, and CETP inhibitors: meta-analysis of randomised controlled trials including 117,411 patients

OBJECTIVE

To investigate the effects on cardiovascular outcomes of drug interventions that increase high density lipoprotein levels.

DESIGN

Meta-analysis.

STUDIES REVIEWED

Therapeutic benefit of niacin, fibrates, and cholesteryl ester transfer protein (CETP) inhibitors on cardiovascular events (all cause mortality, coronary heart disease mortality, non-fatal myocardial infarction, and stroke).

RESULTS

117,411 patients were randomised in a total of 39 trials. All interventions increased the levels of high density lipoprotein cholesterol. No significant effect was seen on all cause mortality for niacin (odds ratio 1.03, 95% confidence interval 0.92 to 1.15, P=0.59), fibrates (0.98, 0.89 to 1.08, P=0.66), or CETP inhibitors (1.16, 0.93 to 1.44, P=0.19); on coronary heart disease mortality for niacin (0.93, 0.76 to 1.12, P=0.44), fibrates (0.92, 0.81 to 1.04, P=0.19), or CETP inhibitors (1.00, 0.80 to 1.24, P=0.99); or on stroke outcomes for niacin (0.96, 0.75 to 1.22, P=0.72), fibrates (1.01, 0.90 to 1.13, P=0.84), or CETP inhibitors (1.14, 0.90 to 1.45, P=0.29). In studies with patients not receiving statins (before the statin era), niacin was associated with a significant reduction in non-fatal myocardial infarction (0.69, 0.56 to 0.85, P=0.0004). However, in studies where statins were already being taken, niacin showed no significant effect (0.96, 0.85 to 1.09, P=0.52). A significant difference was seen between these subgroups (P=0.007). A similar trend relating to non-fatal myocardial infarction was seen with fibrates: without statin treatment (0.78, 0.71 to 0.86, P<0.001) and with all or some patients taking statins (0.83, 0.69 to 1.01, P=0.07); P=0.58 for difference.

CONCLUSIONS

Neither niacin, fibrates, nor CETP inhibitors, three highly effective agents for increasing high density lipoprotein levels, reduced all cause mortality, coronary heart disease mortality, myocardial infarction, or stroke in patients treated with statins. Although observational studies might suggest a simplistic hypothesis for high density lipoprotein cholesterol, that increasing the levels pharmacologically would generally reduce cardiovascular events, in the current era of widespread use of statins in dyslipidaemia, substantial trials of these three agents do not support this concept.

A review on the traditional Chinese medicinal herbs and formulae with hypolipidemic effect

Hyperlipidemia, characterized by the abnormal blood lipid profiles, is one of the dominant factors of many chronic diseases such as diabetes, obesity, and cardiovascular diseases (CVD). For the low cost, effectiveness, and fewer side effects, the popularity of using traditional Chinese medicine (TCM) to handle hyperlipidemia is increasing and its role in health care has been recognized by the public at large. Despite the importance of TCM herbs and formulations, there is no comprehensive review summarizing their scientific findings on handling hyperlipidemia. This review summarizes the recent experimental and clinical results of nine representative single Chinese herbs and seven classic TCM formulae that could improve lipid profiles so as to help understand and compare their underlying mechanisms. Most of single herbs and formulae demonstrated the improvement of hyperlipidemic conditions with multiple and diverse mechanisms of actions similar to conventional Western drugs in spite of their mild side effects. Due to increasing popularity of TCM, more extensive, well-designed preclinical and clinical trials on the potential synergistic and adverse side effects of herb-drug interactions as well as their mechanisms are warranted. Hyperlipidemic patients should be warned about the potential risks of herb-drug interactions, particularly those taking anticoagulants and antiplatelet drugs.

Why targeting HDL should work as a therapeutic tool, but has not

Atherosclerosis is one of the most common causes of death and disability in the United States today despite the availability of statins, which reduce hyperlipidemia, a risk factor that predisposes individuals to this disease. Epidemiology of human populations has overwhelmingly demonstrated an inverse correlation between the concentration of plasma high-density lipoprotein (HDL) cholesterol (HDL-C) and the likelihood of developing cardiovascular disease (CVD). Decades of observations and mechanistic studies suggest that one protective function of HDL is its central role in reverse cholesterol transport. In this pathway, the ATP-binding cassette transporter A1 releases intracellular cholesterol, which is packaged with apolipoprotein A-I (apoA-I) into nascent HDL particles and released from the plasma membrane. Further lipidation and maturation of HDL occur in plasma with the eventual uptake by the liver where cholesterol is removed. It is generally accepted that CVD risk can be reduced if plasma HDL-C levels are elevated. Several different pharmacological approaches have been tried; the most popular approach targets the movement of cholesteryl ester from HDL to triglyceride-rich particles by cholesteryl ester transfer protein. Inhibition of cholesteryl ester transfer protein increases plasma HDL-C concentration; however, beneficial effects have yet to be demonstrated, likely the result of off-target effects. These revelations have led to a reevaluation of how elevating HDL concentration could decrease risk. A recent, landmark study showed that the inherent cholesterol efflux capacity of an individual's plasma was a better predictor of CVD status than overall HDL-C concentration. Even more provocative are recent studies showing that apoA-I, the principle protein component of HDL modulates cellular inflammation and oxidation. The following will review all these potential routes explaining how HDL apoA-I can reduce the risk of CVD.

Low-density lipoprotein-cholesterol-induced endothelial dysfunction and oxidative stress: the role of statins

SIGNIFICANCE

Cardiovascular diseases (CVD) represent a major public health burden. High low-density lipoprotein (LDL)-cholesterol is a recognized pathogenic factor for atherosclerosis, and its complications and statins represent the most potent and widely used therapeutic approach to prevent and control these disorders.

RECENT ADVANCES

A number of clinical and experimental studies concur to identify endothelial dysfunction as a primary step in the development of atherosclerosis, as well as a risk factor for subsequent clinical events. Oxidant stress resulting from chronic elevation of plasma LDL-cholesterol (LDL-chol) is a major contributor to both endothelial dysfunction and its complications, for example, through alterations of endothelial nitric oxide signaling.

CRITICAL ISSUES

Statin treatment reduces morbidity and mortality of CVD, but increasing evidence questions that this is exclusively through reduction of plasma LDL-chol. The identification of ancillary effects on (cardio)vascular biology, for example, through their modulation of oxidative stress, will not only increase our understanding of their mechanisms of action, with a potential broadening of their indication(s), but also lead to the identification of new molecular targets for future therapeutic developments in CVD.

FUTURE DIRECTIONS

Further characterization of molecular pathways targeted by statins, for example, not directly mediated by changes in plasma lipid concentrations, should enable a more comprehensive approach to the pathogenesis of (cardio)vascular disease, including, for example, epigenetic regulation and fine tuning of cell metabolism.

Prevalence of persistent lipid abnormalities in statin-treated patients: Belgian results of the Dyslipidaemia International Study (DYSIS)

AIM

A substantial number of cardiovascular events are not prevented by statin therapy, which is still regarded as the first-line therapy for hyperlipidaemia. Insights into the prevalence of lipid abnormalities of statin-treated patients in Belgium are lacking and may shed light on an unmet medical need for optimal use of current lipid-lowering therapies. This study aims to assess the prevalence and types of persistent lipid abnormalities in patients receiving statin therapy in a real-life primary care setting in Belgium.

METHODS

This cross-sectional cohort study was designed to estimate the prevalence of specific lipid abnormalities in statin-treated patients in Belgium. Total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglycerides were recorded from the patients' medical record. Patient's total cardiovascular risk and corresponding lipid treatment goals were defined based on the recent European Society of Cardiology/European Atherosclerosis Society recommendations.

RESULTS

Overall, 56.2% of the statin-treated patients were not at goal for LDL-C. Low HDL-C (< 40 mg dl(-1) in men, < 45 mg dl(-1) in women) and elevated triglycerides (> 150 mg dl(-1) ) were seen in 16.3% and 29.0% of patients, respectively. Very high-risk patients were more likely to have LDL-C not at goal (71.4% of them), while 60.0% of high-risk patients and 34.1% of moderate-risk patients were not at goal for LDL-C. Use of ezetimibe (10 mg) was strongly associated with meeting LDL-C goals (OR 16.9, p < 0.0001).

CONCLUSION

In Belgium, lipid abnormalities remained highly prevalent despite statin treatment, with more than half of all patients not reaching their LDL-C treatment goal. This finding clearly indicates that more aggressive lipid-lowering treatment is required in clinical daily practice to achieve the goals of the current guidelines.

Bioactive constituents from "triguero" asparagus improve the plasma lipid profile and liver antioxidant status in hypercholesterolemic rats

We have previously shown that the Andalusian-cultivated Asparagus officinalis L. “triguero” variety produces hypocholesterolemic and hepatoprotective effects on rats. This asparagus is a rich source of phytochemicals although we hypothesized there would be some of them more involved in these functional properties. Thus, we aimed to study the effects of asparagus (500 mg/kg body weight (bw)/day) and their partially purified fractions in flavonoids (50 mg/kg bw/day), saponins (5 mg/kg bw/day) and dietary fiber (500 mg/kg bw/day) on oxidative status and on lipid profile in rats fed a cholesterol-rich diet. After 5 weeks treatment, plasma lipid values, hepatic enzyme activities and liver malondialdehyde (MDA) concentrations were measured. With the exception of the saponin fraction (SF), the administration of lyophilized asparagus (LA), fiber fraction (FF), and flavonoid fraction (FVF) to hypercholesterolemic rats produced a significant hypolipidemic effect compare to a high-cholesterol diet (HCD). In addition, the LA and FVF groups exhibited a significant increase in enzyme activity from multiple hepatic antioxidant systems including: superoxide dismutase, catalase, and gluthatione reductase/peroxidase as well as a decrease in MDA concentrations compared to HCD group. These results demonstrate that “triguero” asparagus possesses bioactive constituents, especially dietary fiber and flavonoids, that improve the plasma lipid profile and prevent hepatic oxidative damage under conditions of hypercholesterolemia.

Melatonin ameliorates low-grade inflammation and oxidative stress in young Zucker diabetic fatty rats

The aim of this study was to investigate the effects of melatonin on low-grade inflammation and oxidative stress in young male Zucker diabetic fatty (ZDF) rats, an experimental model of metabolic syndrome and type 2 diabetes mellitus (T2DM). ZDF rats (n = 30) and lean littermates (ZL) (n = 30) were used. At 6 wk of age, both lean and fatty animals were subdivided into three groups, each composed of 10 rats: naive (N), vehicle treated (V), and melatonin treated (M) (10 mg/kg/day) for 6 wk. Vehicle and melatonin were added to the drinking water. Pro-inflammatory state was evaluated by plasma levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and C-reactive protein (CRP). Also, oxidative stress was assessed by plasma lipid peroxidation (LPO), both basal and after Fe(2+)/H2O2 inducement. ZDF rats exhibited higher levels of IL-6 (112.4 ± 1.5 pg/mL), TNF-α (11.0 ± 0.1 pg/mL) and CRP (828 ± 16.0 µg/mL) compared with lean rats (IL-6, 89.9 ± 1.0, P < 0.01; TNF-α, 9.7 ± 0.4, P < 0.01; CRP, 508 ± 21.5, P < 0.001). Melatonin lowered IL-6 (10%, P < 0.05), TNF-α (10%, P < 0.05), and CRP (21%, P < 0.01). Basal and Fe(2+)/H2O2-induced LPO, expressed as malondialdehyde equivalents (µmol/L), were higher in ZDF rats (basal, 3.2 ± 0.1 versus 2.5 ± 0.1 in ZL, P < 0.01; Fe(2+)/H2O2-induced, 8.7 ± 0.2 versus 5.5 ± 0.3 in ZL; P < 0.001). Melatonin improved basal LPO (15%, P < 0.05) in ZDF rats, and Fe(2+)/H2O2- induced LPO in both ZL (15.2%, P < 0.01) and ZDF rats (39%, P < 0.001). These results demonstrated that oral melatonin administration ameliorates the pro-inflammatory state and oxidative stress, which underlie the development of insulin resistance and their consequences, metabolic syndrome, diabetes, and cardiovascular disease.

Fat depots, free fatty acids, and dyslipidemia

Body fat deposition and excess free fatty acid (FFA) metabolism contribute to dyslipidemia and the adverse health consequences of obesity. Individuals with upper body obesity have impaired functioning of adipocytes, the primary fatty acid storage site. Excess visceral fat is strongly associated with impaired suppression of FFA release in response to insulin, as well as with hypertriglyceridemia and low concentrations of high density lipoprotein (HDL) cholesterol. High FFA concentrations can induce insulin resistance in muscle and liver. Furthermore, failure of hyperinsulinemia to normally suppress FFA is associated with impaired carbohydrate oxidation and muscle glucose storage, reduced hepatic insulin clearance and elevated triglycerides. Understanding the impact of body fat distribution on FFA metabolism and dyslipidemia is critical for determining the link between overweight and obesity and cardiovascular disease risk. In the current review, we will explore the relationship between adipose tissue, body fat depots, and FFA metabolism.

Antioxidant activity of melatonin in diabetes in relation to the regulation and levels of plasma Cu, Zn, Fe, Mn, and Se in Zucker diabetic fatty rats

OBJECTIVE

To study the antioxidant activity of melatonin in diabetes in relation to the regulation and levels of plasma copper (Cu), zinc (Zn), iron (Fe), manganese (Mn), and selenium (Se) in Zucker diabetic fatty (ZDF) and lean (ZL) rats.

METHODS

At 6 wk of age, both ZDF (n = 30) and ZL (n = 30) animals were subdivided into three groups: control (C) (n = 10), vehicle (V) (n = 10), and melatonin-treated (M) (10 mg/kg/d; n = 10) rats for a 6-wk period. At the end of treatment period, plasma mineral levels were measured by flame (Cu, Zn, and Fe), electrothermal (Mn), and hydride generation (Se) atomic absorption spectrometry.

RESULTS

ZDF rats had significantly higher Cu, Fe, and Mn plasma levels than did ZL rats (P < 0.05). No significant differences were found between control and vehicle groups (P > 0.05). Melatonin treatment did not influence plasma levels of these antioxidant minerals (Cu, Zn, Fe, and Mn) in ZDF groups (M-ZDF versus C-ZDF group) and ZL (M-ZL versus C-ZL group) rats with the exception of Zn, whose mean plasma level was lower in the M-ZL versus C-ZL group. However, plasma Se levels increased significantly (P < 0.05) after melatonin supplementation in both groups (M-ZDF and M-ZL).

CONCLUSION

The higher mean plasma Cu, Fe, and Mn levels in the ZDF group are related to the enhanced oxidative stress in diabetes and obesity. Melatonin administration significantly enhanced plasma Se levels in both groups (M-ZDF and M-ZL). This is the first study to report that melatonin treatment increases plasma Se levels.

Antihyperlipidemic effect of methanolic extract from Opuntia joconostle seeds in mice fed a hypercholesterolemic diet

The purpose of this study was to evaluate the hypolipidemic effect of a methanolic extract from Opuntia joconostle seeds fed to mice in a hypercholesterolemic diet. Acute toxicity of the methanolic extract was investigated by an established method. Phenolic composition and antioxidant activity were determined by high-performance liquid chromatography and DPPH, respectively. The total phenolic content of Opuntia joconostle seeds was 47.85 ± 1.29 mg gallic acid equivalents/g dry weight. The main phenolic compounds were identified as quercetin, rutin, and cafeic acid. Percent inhibition of DPPH⁺ was 49.76 ± 0.49 %. The oral LD₅₀ for the methanolic extract from the Opuntia joconostle seeds was >5,000 mg/kg BW. Mice fed a hypercholesterolemic diet for six days exhibited significantly (P ≤ 0.001) higher plasma lipid levels than mice fed a normal diet. Remarkably, supplementation with methanolic extract from Opuntia joconostle at doses of 1, 2, and 5 g/kg body weight significantly (P ≤ 0.001) prevented the increase in total cholesterol, low-density lipoprotein cholesterol, triglycerides level, and atherogenic index. Similar concentrations of the HDL cholesterol were observed in both treated and control groups. A significant dose-dependent reduction in lipid levels was noted for treated groups compared to the hypercholesterolemic group. We attribute this result to the seeds' phenolic composition. This methanolic extract has potential to be included in short-term hypercholesterolemia treatment regimens as it exhibits hypolipidemic activity with no apparent toxic manifestations.

Prevalence of low LDL-cholesterol levels and elevated high-sensitivity C-reactive protein levels in apparently healthy Korean adults

BACKGROUND AND AIMS

The Justification for the Use of Statins in Primary Prevention: An Intervention Trial Evaluating Rosuvastatin (JUPITER) reported reduced cardiovascular and all-cause mortality in patients with elevated C-reactive protein (CRP) and low LDL-cholesterol (LDL-C) levels treated with statins. The aims of this study were to determine the proportion of "JUPITER-eligible" Korean adults and to describe their characteristics.

METHODS AND RESULTS

As many as 15,154 subjects with serum LDL-C levels <130 mg/dL were selected among 28,851 middle-aged participants (men ≥ 50 years, women ≥ 60 years) who participated in a routine health check-up program. Among the participants with LDL-C less than 130 mg/dL, only 15% had CRP levels ≥2.0 mg/L (7.9% of original participants). Subjects were divided into four groups according to CRP levels (<0.5, ≥0.5 - <1.0, ≥1.0 - <2.0, and ≥2.0 mg/L). Mean HDL-C and apolipoprotein A1 levels decreased significantly as the mean CRP values increased. The insulin and homeostasis model of insulin resistance was significantly different according to CRP quartile. The number of subjects with metabolic syndrome and its components increased significantly as the mean CRP values increased.

CONCLUSION

In this Asian population, few individuals with low LDL-C levels had CRP levels ≥2.0 mg/L. Elevated CRP levels were associated with components of atherogenic dyslipidemia and insulin resistance. Additional clinical trials should be designed and performed in different ethnic groups, as different CRP cut-off levels may be required in different ethnic groups.

Therapeutic strategies to deplete macrophages in atherosclerotic plaques

Macrophages can be found in all stages of atherosclerosis and are major contributors of atherosclerotic plaque development, progression and destabilization. Continuous recruitment of monocytes drives this chronic inflammatory disease, which can be intervened by several strategies: reducing the inflammatory stimulus by lowering circulating lipids and promoting cholesterol efflux from plaque, direct and indirect targeting of adhesion molecules and chemokines involved in monocyte adhesion and transmigration and inducing macrophage death in atherosclerotic plaques in combination with anti-inflammatory drugs. This review discusses the outlined strategies to deplete macrophages from atherosclerotic plaques to promote plaque stabilization.

Low dietary folate and methylenetetrahydrofolate reductase deficiency may lead to pregnancy complications through modulation of ApoAI and IFN-γ in spleen and placenta, and through reduction of methylation potential

SCOPE

Genetic or nutritional disturbances in folate metabolism lead to hyperhomocysteinemia and adverse reproductive outcomes. Folate-dependent homocysteine remethylation is required for methylation reactions and may influence choline/betaine metabolism. Hyperhomocysteinemia has been suggested to play a role in inflammation. The goal of this study was to determine whether folate-related pregnancy complications could be due to altered expression of some inflammatory mediators or due to disturbances in methylation intermediates.

METHODS AND RESULTS

Pregnant mice with or without a deficiency of methylenetetrahydrofolate reductase (MTHFR) were fed control diets or folate-deficient (FD) diets; tissues were collected at embryonic day 14.5. FD decreased plasma phosphocholine and increased plasma glycerophosphocholine and lysophosphatidylcholine. Liver betaine, phosphocholine, and S-adenosylmethionine:S-adenosylhomocysteine ratios were reduced in FD. In liver, spleen, and placenta, the lowest levels of apolipoprotein AI (ApoAI) were observed in Mthfr(+/-) mice fed FD. Increased interferon-gamma (IFN-γ) was observed in spleen and placentae due to FD or Mthfr genotype. Plasma homocysteine correlated negatively with liver and spleen ApoAI, and positively with IFN-γ.

CONCLUSION

Low dietary folate or Mthfr deficiency during pregnancy may result in adverse pregnancy outcomes by altering expression of the inflammatory mediators ApoAI and IFN-γ in spleen and placenta. Disturbances in choline metabolism or methylation reactions may also play a role.