Targeting the Cholesterol Paradigm in the Risk Reduction for Atherosclerotic Cardiovascular Disease: Does the Mechanism of Action of Pharmacotherapy Matter for Clinical Outcomes?

Hypercholesterolemia is a well-established risk factor for atherosclerotic cardiovascular disease (ASCVD). Low-density lipoprotein cholesterol (LDL-C) has been labeled as "bad" cholesterol and high-density lipoprotein cholesterol (HDL-C) as "good" cholesterol. The prevailing hypothesis is that lowering blood cholesterol levels, especially LDL-C, reduces vascular deposition and retention of cholesterol or apolipoprotein B (apoB)-containing lipoproteins which are atherogenic. We review herein the clinical trial data on different pharmacological approaches to lowering blood cholesterol and propose that the mechanism of action of cholesterol lowering, as well as the amplitude of cholesterol reduction, are critically important in leading to improved clinical outcomes in ASCVD. The effects of bile acid sequestrants, fibrates, niacin, cholesteryl ester transfer protein (CETP) inhibitors, apolipoprotein A-I and HDL mimetics, apoB regulators, acyl coenzyme A: cholesterol acyltransferase (ACAT) inhibitors, cholesterol absorption inhibitors, statins, and proprotein convertase subtilisin kexin 9 (PCSK9) inhibitors, among other strategies are reviewed. Clinical evidence supports that different classes of cholesterol lowering or lipoprotein regulating approaches yielded variable effects on ASCVD outcomes, especially in cardiovascular and all-cause mortality. Statins are the most widely used cholesterol lowering agents and have the best proven cardiovascular event and survival benefits. Manipulating cholesterol levels by specific targeting of apoproteins or lipoproteins has not yielded clinical benefit. Understanding why lowering LDL-C by different approaches varies in clinical outcomes of ASCVD, especially in survival benefit, may shed further light on our evolving understanding of how cholesterol and its carrier lipoproteins are involved in ASCVD and aid in developing effective pharmacological strategies to improve the clinical outcomes of ASCVD.

The Beneficial Effects of Alpha Lipoic Acid Supplementation on Lp-PLA2 Mass and Its Distribution between HDL and apoB-Containing Lipoproteins in Type 2 Diabetic Patients: A Randomized, Double-Blind, Placebo-Controlled Trial.

Lipoprotein-associated phospholipase A2 (Lp-PLA2) is a new specific vascular inflammation biomarker that is carried by the lipoproteins in the blood and plays a prominent role in the pathogenesis of atherosclerosis. Increased Lp-PLA2 levels and impaired Lp-PLA2 distribution across high-density lipoprotein (HDL) and non-HDL lipoproteins have been reported in diabetic patients, which is associated with the increase in cardiovascular disease (CVD) risk. This study is aimed at investigating the effect of alpha lipoic acid (ALA), as an antioxidant with potential cardioprotective properties, on the Lp-PLA2 mass and its distribution in diabetic patients. In a double-blind, randomized, placebo-controlled clinical trial, seventy diabetic patients were randomly allocated to ALA (1200 mg ALA as two 600 mg capsules/day) and placebo (two maltodextrin capsules/day) groups. The serum levels of total Lp-PLA2 mass, HDL-Lp-PLA2, oxidized low-density lipoproteins (ox-LDL), apolipoprotein A1 (apo A1), lipid profiles, fasting blood sugar (FBS), and insulin were measured, and apolipoprotein B- (apoB-) associated Lp-PLA2 and homeostasis model of assessment index (HOMA-IR) were calculated at the baseline and after 8 weeks of intervention. ALA significantly decreased the ox-LDL, total Lp-PLA2 mass, apoB-associated Lp-PLA2, and percent of apoB-associated Lp-PLA2 and triglyceride and increased the percent of HDL-Lp-PLA2 compared with the placebo group but had no significant effect on HDL-Lp-PLA2 mass, apo A1, lipid profiles, and glycemic indices. There was a positive correlation between the reduction in the ox-LDL level and total Lp-PLA2 mass in the ALA group. In conclusion, ALA may decrease the CVD risk by reducing the ox-LDL and Lp-PLA2 mass and improving the Lp-PLA2 distribution among lipoproteins in type 2 diabetic patients.

The effects of flaxseed supplementation on metabolic status in women with polycystic ovary syndrome: a randomized open-labeled controlled clinical trial.

BACKGROUND: Polycystic Ovary Syndrome (PCOS) is known as the most common endocrine disorder of women in reproductive ages. With the increasing prevalence of PCOS in different countries, the use of herbal medicine as an alternative treatment is growing in these patients. This study aimed to evaluate the effects of flaxseed powder supplementation on metabolic biomarkers of patients with PCOS. METHODS: This randomized open-labeled controlled clinical trial was conducted on 41 patients with PCOS. The participants were randomized to take either flaxseed powder (30 g/day) plus lifestyle modification or only lifestyle modification for 12 weeks. Anthropometric and biochemical evaluations were performed for all patients at the beginning and end of the study. RESULTS: The flaxseed group showed a significant reduction in body weight, insulin concentration, Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), Triglycerides (TG), high-sensitivity C-Reactive Protein (hs-CRP), and leptin and an increase in Quantitative Insulin-Sensitivity Check Index (QUICKI), High Density Lipoprotein (HDL), and adiponectin compared to the baseline (p < 0.05). Flaxseed supplementation also led to a significant reduction in insulin concentration, HOMA-IR, TG, hs-CRP, Interleukin 6 (IL- 6), and leptin and an increase in QUICKI, HDL, and adiponectin compared to the control group (p < 0.05). No significant changes were observed in other parameters. CONCLUSIONS: Flaxseed supplementation plus lifestyle modification was more effective compared to lifestyle modification alone in biochemical and anthropometric variables in patients with PCOS. TRIAL REGISTRATION: The trial protocol was approved by the Ethics Board at Ahvaz Jundishapur University of Medical Sciences and was registered at Iranian Registry of Clinical Trials (code: IRCT20120704010181N11).

Attenuation of atherogenic apo B-48-dependent hyperlipidemia and high density lipoprotein remodeling induced by vitamin C and E combination and their beneficial effect on lethal ischemic heart disease in mice.

BACKGROUND AND AIMS: Atherosclerotic cardiovascular disease is highly prevalent and its underlying pathogenesis involves dyslipidemia including pro-atherogenic high density lipoprotein (HDL) remodeling. Vitamins C and E have been proposed as atheroprotective agents for cardiovascular disease management. However, their effects and benefits on high density lipoprotein function and remodeling are unknown. In this study, we evaluated the role of vitamin C and E on non HDL lipoproteins as well as HDL function and remodeling, along with their effects on inflammation/oxidation biomarkers and atherosclerosis in atherogenic diet-fed SR-B1 KO/ApoER61h/h mice. METHODS AND RESULTS: Mice were pre-treated for 5 weeks before and during atherogenic diet feeding with vitamin C and E added to water and diet, respectively. Compared to a control group, combined vitamin C and E administration reduced serum total cholesterol and triglyceride levels by decreasing apo B-48-containing lipoproteins, remodeled HDL particles by reducing phospholipid as well as increasing PON1 and apo D content, and diminished PLTP activity and levels. Vitamin supplementation improved HDL antioxidant function and lowered serum TNF-α levels. Vitamin C and E combination attenuated atherogenesis and increased lifespan in atherogenic diet-fed SR-B1 KO/ApoER61h/h mice. CONCLUSIONS: Vitamin C and E administration showed significant lipid metabolism regulating effects, including HDL remodeling and decreased levels of apoB-containing lipoproteins, in mice. In addition, this vitamin supplementation generated a cardioprotective effect in a murine model of severe and lethal atherosclerotic ischemic heart disease.

Açai (Euterpe oleracea Mart.) dietary intake affects plasma lipids, apolipoproteins, cholesteryl ester transfer to high-density lipoprotein and redox metabolism: A prospective study in women.

The açai fruit (Euterpe oleracea Martius), which is native to the Brazilian Amazon region, was shown to have high polyphenols and MUFA contents. In this study, we aimed to assess the effects of açai consumption on plasma lipids, apolipoproteins, the transfer of lipids to HDL (which is a relevant HDL function), and some biomarkers of redox metabolism. Forty healthy volunteer women aged 24 ± 3 years consumed 200 g of açai pulp/day for 4 weeks; their clinical variables and blood sample were obtained before and after this period. Açai pulp consumption did not alter anthropometric parameters, systemic arterial pressure, glucose, insulin and total, LDL and HDL cholesterol, triglycerides and apolipoprotein (apo) B, but it did increase the concentration of apo A-I. Açai consumption decreased the ROS, ox-LDL and malondialdehyde while increasing the activity of antioxidative paraoxonase 1. Overall, the total antioxidant capacity (TAC) was increased. Regarding the transfer of plasma lipids to HDL, açai consumption increased the transfer of cholesteryl esters (p = 0.0043) to HDL. Unesterified cholesterol, phospholipids and triglyceride transfers were unaffected. The increase in apo A-I and the cholesteryl ester transfer to HDL after the açai intake period suggests that an improvement in the metabolism of this lipoprotein occurred, and it is well known that HDL is protective against atherosclerosis. Another important finding was the general improvement of the anti-oxidant defences elicited by açai consumption. Our data indicate that açai has favourable actions on plasma HDL metabolism and anti-oxidant defence; therefore açai could have a beneficial overall role against atherosclerosis, and it is a consistently good candidate to consider as a functional food.

Attenuation of atherogenic apo B-48-dependent hyperlipidemia and high density lipoprotein remodeling induced by vitamin C and E combination and their beneficial effect on lethal ischemic heart disease in mice

BACKGROUND AND AIMS: Atherosclerotic cardiovascular disease is highly prevalent and its underlying pathogenesis involves dyslipidemia including pro-atherogenic high density lipoprotein (HDL) remodeling. Vitamins C and E have been proposed as atheroprotective agents for cardiovascular disease management. However, their effects and benefits on high density lipoprotein function and remodeling are unknown. In this study, we evaluated the role of vitamin C and E on non HDL lipoproteins as well as HDL function and remodeling, along with their effects on inflammation/ oxidation biomarkers and atherosclerosis in atherogenic diet-fed SR-B1 KO/ApoER61h/h mice. METHODS AND RESULTS: Mice were pre-treated for 5 weeks before and during atherogenic diet feeding with vitamin C and E added to water and diet, respectively. Compared to a control group, combined vitamin C and E administration reduced serum total cholesterol and triglyceride levels by decreasing apo B-48-containing lipoproteins, remodeled HDL particles by reducing phospholipid as well as increasing PON1 and apo D content, and diminished PLTP activity and levels. Vitamin supplementation improved HDL antioxidant function and lowered serum TNF-α levels. Vitamin C and E combination attenuated atherogenesis and increased lifespan in atherogenic diet-fed SR-B1 KO/ApoER61h/h mice. CONCLUSIONS: Vitamin C and E administration showed significant lipid metabolism regulating effects, including HDL remodeling and decreased levels of apoB-containing lipoproteins, in mice. In addition, this vitamin supplementation generated a cardioprotective effect in a murine model of severe and lethal atherosclerotic ischemic heart disease.

IMMUNO-MODULATORY PROPERTIES OF PREBIOTICS EXTRACTED FROM vernonia amygdalina.

BACKGROUND: Vernonia amygdalina, commonly called bitter-leaf, is widely consumed in many parts of Africa, and Nigeria, in particular. The leaf extract has been reported to have antimicrobial, anti-plasmodial, anti-helminthic, as well as prebiotic properties, but its immuno-modulatory effects have not been well-studied, neither have the prebiotics been identified. This study evaluated the immuno-modulatory properties of the aqueous leaf extract and identified the prebiotic components. METHODS: The immuno-modulatory potential was evaluated by monitoring the effects of oral administration of the extract on immunological, haematological and lipid profiles of Rattus norvegicus, while the prebiotic components were identified by thin layer chromatography (TLC), following liquid-liquid fractionation of the extract. RESULTS: Consumption of the extract caused significant increases in CD4+-, white blood cell-, total lymphocyte- and high density lipid (HDL) counts; decreases in low density lipid (LDL) and triglycerides and no significant effect on haemoglobin (Hb) and packed cell volume (PCV) in the blood of test animals. The water-soluble fraction of the extract contained most of the phyto-constituents of the extract and Thin Layer Chromatographic analysis of the fraction revealed the presence of fructo-oligosaccharide and galacto-oligosaccharide prebiotics. CONCLUSION: The results from this study have shown that the aqueous leaf extract of V. amygdalina has positive immune-modulatory and haematologic effects and contains some important prebiotic compounds.

Olive oil polyphenols enhance high-density lipoprotein function in humans: a randomized controlled trial.

OBJECTIVE: Olive oil polyphenols have shown beneficial properties against cardiovascular risk factors. Their consumption has been associated with higher cholesterol content in high-density lipoproteins (HDL). However, data on polyphenol effects on HDL quality are scarce. We, therefore, assessed whether polyphenol-rich olive oil consumption could enhance the HDL main function, its cholesterol efflux capacity, and some of its quality-related properties, such HDL polyphenol content, size, and composition. APPROACH AND RESULTS: A randomized, crossover, controlled trial with 47 healthy European male volunteers was performed. Participants ingested 25 mL/d of polyphenol-poor (2.7 mg/kg) or polyphenol-rich (366 mg/kg) raw olive oil in 3-week intervention periods, preceded by 2-week washout periods. HDL cholesterol efflux capacity significantly improved after polyphenol-rich intervention versus the polyphenol-poor one (+3.05% and -2.34%, respectively; P=0.042). Incorporation of olive oil polyphenol biological metabolites to HDL, as well as large HDL (HDL2) levels, was higher after the polyphenol-rich olive oil intervention, compared with the polyphenol-poor one. Small HDL (HDL3) levels decreased, the HDL core became triglyceride-poor, and HDL fluidity increased after the polyphenol-rich intervention. CONCLUSIONS: Olive oil polyphenols promote the main HDL antiatherogenic function, its cholesterol efflux capacity. These polyphenols increased HDL size, promoted a greater HDL stability reflected as a triglyceride-poor core, and enhanced the HDL oxidative status, through an increase in the olive oil polyphenol metabolites content in the lipoprotein. Our results provide for the first time a first-level evidence of an enhancement in HDL function by polyphenol-rich olive oil.

Induction of apolipoprotein A-I gene expression by black seed (Nigella sativa) extracts.

CONTEXT: Black seed [Nigella sativa L. (Ranunculaceae)] has been shown in animal models to lower serum cholesterol levels. OBJECTIVES: In order to determine if extracts from black seed have any effects on high-density lipoprotein (HDL), we characterized the effects of black seed extract on apolipoprotein A-I (apo A-I) gene expression, the primary protein component of HDL. MATERIALS AND METHODS: Hepatocytes (HepG2) and intestinal cells (Caco-2) were treated with black seed extracts, and Apo A-I, peroxisome proliferator-activated receptor α (PPARα), and retinoid-x-receptor α (RXRα) were measured by Western blot analysis. Apo A-I mRNA levels were measured by quantitative real-time polymerase chain reaction and apo A-I gene transcription was measured by transient transfection of apo A-I reporter plasmids. RESULTS: Extracts from black seeds significantly increased hepatic and intestinal apo A-I secretion, as well as apo A-I mRNA and gene promoter activity. This effect required a PPARα binding site in the apo A-I gene promoter. Treatment of the extract with either heat or trypsin had no effect on its ability to induce apo A-I secretion. Treatment with black seed extract induced PPARα expression 9-fold and RXRα expression 2.5-fold. Furthermore, the addition of PPARα siRNA but not a control siRNA prevented some but not all the positive effects of black seed on apo A-I secretion. DISCUSSION: Black seed extract is a potent inducer of apo A-I gene expression, presumably by enhancing PPARα/RXRα expression. CONCLUSIONS: We conclude that black seed may have beneficial effects in treating dyslipidemia and coronary heart disease.

Effect of green tea extract on body weight, serum glucose and lipid profile in streptozotocin-induced diabetic rats. A dose response study.

OBJECTIVE: To examine the effect of green tea extract on body weight, serum levels of glucose, and lipids in streptozotocin-induced diabetic rats. METHODS: This experimental study was carried out in the Diabetes Research Center, Ahvaz University of Medical Sciences, Ahvaz, Iran from January 2011 to March 2011. Forty-eight male wistar rats (200-250 g) were divided randomly into 6 groups. Diabetes was induced by a single intraperitoneal injection of stereptozotocin (55 mg/kg). The experimental groups received alcohol extract of green tea leaves (100 mg/kg and 200 mg/kg) for 4 weeks and the body weight of animals were measured every day. Finally, blood samples were collected and analyzed for glucose and lipid profile levels. RESULTS: Administration of green tea extract caused a significant decrease in serum glucose and total cholesterol levels and significantly improved the body weight loss in diabetic rats treated with 200 mg/kg green tea in comparison to diabetic control group. No significant changes were observed in triglyceride (p=0.04), low-density-lipoprotein cholesterol (p=0.000), and high-density-lipoprotein cholesterol levels (p=0.01) following intervention. CONCLUSION: It appears that green tea extract had both antihyperglycemic and hypocholesterolmic effects in diabetic rats, although further work is needed to determine their mechanism.

Effect of vitamin D on insulin sensitivity in elderly patients with impaired fasting glucose.

AIM: Recent data has shown that vitamin D increases insulin sensitivity; however, there is little evidence about the effects of this treatment on elderly people with impaired fasting glucose. The aim of the present study was to investigate the effect of vitamin D treatment on insulin sensitivity and metabolic parameters in elderly people with impaired fasting glucose. METHODS: A total of 28 elderly patients were enrolled into the vitamin D treatment group. The control group included 23 age-, sex- and body mass index-matched elderly participants. The vitamin D treatment group was treated with vitamin D(3) according to serum concentrations of 25(OH)D. RESULTS: With supplementation, 96.0% of patients achieved a mean serum 25(OH)D concentration of 123.2 ± 59.9 nmol/L. After 4.7 ± 2.5 months of treatment, there was a significant decrease in homeostasis model assessment of insulin resistance, insulin and glucose concentrations in the vitamin D treatment group (P = 0.007, P = 0.007, P = 0.037, respectively). Vitamin D treatment significantly increased high-density lipoprotein cholesterol (P = 0.037), but did not cause statistically significant differences in other lipid parameters. CONCLUSION: We found that vitamin D treatment might modify insulin sensitivity in the elderly with impaired fasting glucose.

Effects of omega-3 fatty acids on serum lipids, lipoprotein (a), and hematologic factors in hemodialysis patients.

BACKGROUND: Lipid abnormalities, especially high serum lipoprotein (a) [Lp (a)] concentration, and anemia are two major causes of cardiovascular diseases (CVDs) in hemodialysis patients. Therefore, this study was designed to investigate the effects of marine omega-3 fatty acids on serum lipids, Lp (a), and hematologic factors in hemodialysis patients. METHODS: Thirty-four hemodialysis patients were randomly assigned to either omega-3 fatty acid supplement or placebo group. Patients in the omega-3 fatty acids group received 2080 mg marine omega-3 fatty acids, daily for 10 weeks, whereas the placebo group received a corresponding placebo. At baseline and the end of week 10, 7 mL blood was collected after a 12- to 14-h fast and serum triglyceride, total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), Lp (a), blood hemoglobin, hematocrit, red blood cells (RBCs), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) were measured. RESULTS: Serum triglyceride decreased significantly in the omega-3 fatty acids group at the end of week 10 compared with baseline (p < 0.05) and this reduction was significant in comparison with the placebo group (p < 0.01). No significant differences were observed between the two groups in mean changes of serum total cholesterol, LDL-C, HDL-C, Lp (a), blood hemoglobin, hematocrit, RBC, MCV, MCH, and MCHC. CONCLUSION: The results of our study indicate that marine omega-3 fatty acids can reduce serum triglyceride, as a risk factor for CVD, but it does not affect other serum lipids, Lp (a), and hematologic factors in hemodialysis patients.

[Antioxidants inhibit the oxidative modification of high density lipoproteins].

OBJECTIVE: To study the role and mechanism of antioxidants on inhibiting oxidative modification of high density lipoproteins (HDL). METHODS: Freshly prepared human plasma HDL was treated by incubation with copper ion, hyperchlorite or arterial wall cells. Compared to control, the test groups were treated with addition of different concentration of butylhydroxytoluene (BHT), vitamin C and vitamin E. Then, the relative electrophoretic mobility (REM), thiobarbituric acid-reactive substances (TBARS), ratio of lysolecithin to lecithin (LPC/PC), and lipoprotein moieties were investigated. RESULTS: BHT, vitamin C and vitamin E can significantly inhibit the increasing REM, TBARS, LPC/PC ratio and lipoprotein variation that induced by copper ion and hyperchlorite and arterial wall cells. But these antioxidants act on different manner. CONCLUSION: BHT, vitamin C and vitamin E can inhibit the oxidative modification of HDL and hence could be potential nutrients to prevent atherosclerosis.

Effect of conjugated linoleic acid on body fat accretion in overweight or obese children.

BACKGROUND: Conjugated linoleic acid (CLA) is a supplemental dietary fatty acid that decreases fat mass accretion in young animals. OBJECTIVE: The aim of this study was to determine CLA's efficacy with regard to change in fat and body mass index (BMI; in kg/m(2)) in children. DESIGN: We conducted a 7 +/- 0.5-mo randomized, double-blind, placebo-controlled trial of CLA in 62 prepubertal children aged 6-10 y who were overweight or obese but otherwise healthy. The subjects were randomly assigned to receive 3 g/d of 80% CLA (50:50 cis-9,trans-11 and trans-10,cis-12 isomers) or placebo in chocolate milk. RESULTS: Fifty-three subjects completed the trial (n = 28 in the CLA group, n = 25 in the placebo group). CLA attenuated the increase in BMI (0.5 +/- 0.8) compared with placebo (1.1 +/- 1.1) (P = 0.05). The percentage change in body fat measured by dual-energy X-ray absorptiometry was smaller (P = 0.001) in the CLA group (-0.5 +/- 2.1%) than in the placebo group (1.3 +/- 1.8%). The change in abdominal body fat as a percentage of total body weight was smaller (P = 0.02) in the CLA group (-0.09 +/- 0.9%) than in the placebo group (0.43 +/- 0.6%). There were no significant changes in plasma glucose, insulin, or LDL cholesterol between groups. Plasma HDL cholesterol decreased significantly more (P = 0.05) in the CLA group (-5.1 +/- 7.3 mg/dL) than in the placebo group (-0.7 +/- 8 mg/dL). Bone mineral accretion was lower (P = 0.04) in the CLA group (0.05 +/- 0.03 kg) than in the placebo group (0.07 +/- 0.03 kg). Reported gastrointestinal symptoms did not differ significantly between groups. CONCLUSIONS: CLA supplementation for 7 +/- 0.5 mo decreased body fatness in 6-10-y-old children who were overweight or obese but did not improve plasma lipids or glucose and decreased HDL more than in the placebo group. Long-term investigation of the safety and efficacy of CLA supplementation in children is recommended.

Modulation of lipid metabolism by Centella asiatica in oxidative stress rats.

A study was carried out to investigate the effects of Centella asiatica leaf on lipid metabolism of oxidative stress rats. The rats were fed 0.1% hydrogen peroxide (H(2)O(2)) with either 0.3% (w/w) C. asiatica extract, 5%C. asiatica powder (w/w), or 0.3% (w/w) alpha-tocopherol for 25 wk. Results of the study showed that C. asiatica powder significantly (P < 0.05) lowered serum low-density lipoprotein compared to that of control rats (rats fed H(2)O(2) only). At the end of the study C. asiatica-fed rats were also found to have significantly (P < 0.05) higher high-density lipoprotein and lower triglyceride level compared to rats fed only normal diet. However, cholesterol level of rats fed both C. asiatica extract and powder was found to be significantly (P < 0.05) higher compared to that of control rats. It was interesting to note that consumption of C. asiatica significantly decreased body and liver weights of the rats. Histological examinations revealed no obvious changes in all rats studied. Quantitative analysis of C. asiatica leaf revealed high concentration of total phenolic compounds, in particular, catechin, quercetin, and rutin.

Chlorogenic acid protects paraoxonase 1 activity in high density lipoprotein from inactivation caused by physiological concentrations of hypochlorite.

We hypothesized that chlorogenic acids, the main phenolics in coffee, many fruits and Ilex paraguariensis extracts, protect paraoxonase 1 activity in HDL from inactivation by chlorination at concentrations of HOCl (50 microM) and chlorogenic acid (2-10 microM) compatible with those found in humans. When human HDL was incubated in the presence of HOCl/OCl-, a concentration dependent loss of activity was apparent. Of interest, 5 caffeoylquinic acid at 5 micromol/L affords more than 60% protection of the activity reaching 100% at 25 micromol/L. This compound and the plant sources that are rich in them may be protectors of paraoxonase 1 activity.

Food and food supplements with hypocholesterolemic effects.

Hypercholesterolemia is a predominant risk factor for atherosclerosis and associated coronary and cerebrovascular diseases. Control of cholesterol levels through therapeutic drugs, notably statins, have significantly reduced the risk for developing atherosclerosis and associated cardiovascular diseases. However, adverse effects associated with therapeutic drugs warrant to find other alternative approaches for managing hypercholesterolemia, especially for those with borderline cholesterol levels. Food supplements have increasingly become attractive alternatives to prevent or treat hypercholesterolemia and reduce the risk for cardiovascular diseases. This review summarized current patents on food supplements with claims of hypocholesterolemic effects. They can be mainly divided into four categories based on the active ingredients in the supplements: 1) plant sterols or stanols; 2) fiber or polysaccharides; 3) microorganism-derived; and 4) soy protein and phytoestrogens. The efficacy, mechanisms of action and potential side effects are reviewed for each of the four categories. The hypocholesterolemic effects of plant sterols, fiber, Monascus products and soy protein preparations have been consistently demonstrated in clinical trails whereas the efficacy of some probiotic bacteria and phytoestrogens-containing supplements remains to be established. Accumulative clinical data show that plant sterols, fiber, soy protein and phytoestrogen are generally considered safe and cause no obvious side effects. However, additional clinical studies are required to establish the safety profiles of certain probiotic bacteria as food supplements.

New stemona alkaloids from the roots of Stemona sessilifolia.

From the roots of Stemona sessilifolia, three new stemona-type alkaloids, namely stemosessifoine (1), isooxymaistemonine (2), and isomaistemonine (3), along with eight known alkaloids (bisdehydrostemoninine, isobisdehydrostemoninine, tuberostemonine, bisdehydrotuberostemonine, bisdehydrostemoninine, isobisdehydrostemoninine, stemoninine, and protostemonine), were isolated. Their structures were determined on the basis of extensive 2D-NMR spectroscopic-data analysis and by comparison with reported values in the literature. Compound 1 is a structurally unprecedented alkaloid, and it is depicted to be bioconverted from tuberostemonine as the precursor. Isooxymaistemonine (2) showed a positive effect on the human high-density lipoprotein (HDL) receptor gene CD36 and LIMP II analogous-1 (CLA-1) at the dosage of 10 microg/ml.

[Omega-3 polyunsaturated fatty acids in the prevention of atherosclerosis]. / Az omega-3 többszörösen telítetlen zsírsavak az atherosclerosis megelôzésében.

Cardioprotective action of omega-3 polyunsaturated fatty acids such as eicosapentaenoic and docosahexaenoic acid in fish and alpha-linolenic acid in plants was demonstrated in primary and secondary clinical trials. Fish oil therapy causes a marked decrease in serum triacylglycerol and very low density lipoprotein levels and increases moderately high density lipoprotein levels without any adverse effects. Omega-3 fatty acids decrease slightly, but significantly blood pressure, enhance endothelial function, they have anti-aggregator, anti-thrombotic and anti-inflammatory effects as well. These beneficial effects are in connection with modification of gene transcription levels of some key molecules such as nuclear factor-kappaB and sterol element binding receptor protein-1c, which regulate for example expression of adhesion molecules or several receptors involved in triglyceride synthesis (hepatocyte X receptor, hepatocyte nuclear factor 4alpha, farnesol X receptor, and peroxisome proliferator-activated receptors). On the basis of these observations, the supplementation of the diet with omega-3 fatty acids (fish, fish oil, linseed, and linseed oil or canola oil) is advisable in primary and secondary prevention.

Hypoglycemic and hypolipidemic effects of methanol seed extract of Citrus paradisi Macfad (Rutaceae) in alloxan-induced diabetic Wistar rats.

BACKGROUND: Alcohol decoction of Citrus paradisi Macfad (Rutaceae) seed is reputed for the local management of array of human diseases including, anemia, diabetes mellitus and obesity by some Yoruba herbalists (SouthWest, Nigeria). Despite its historic use, scientific evaluation of its folkloric use in the management of diabetes mellitus is scarce. OBJECTIVES: The present study was designed at investigating the glucose and lipid lowering effects of methanol seed extract of Citrus paradisi Macfad (MECP) in alloxan-induced diabetic rats. In addition, the phytochemical analysis of the extract was also conducted using standard procedures. METHODS: Young adult, male, alloxan-induced diabetic rats were randomly divided into groups I - VI with 12 rats in each group. Group I rats were the normal untreated rats while group II rats served as the diabetic untreated rats while Rats in groups III - VI served as diabetic rats treated with 100, 300 and 600 mg/kg/day MECP and 20 mg/kg/ day metformin, respectively, for 30 days. On the 15th and respectively, 31st day, blood samples from the fasted rats were obtained for fasting plasma glucose (FPG), plasma triglycerides (TG), total cholesterol (TC), high density lipoprotein- cholesterol (HDL-c), low density lipoprotein-cholesterol (LDL-c) and very low density lipoprotein-cholesterol (VLDL-c) from the sacrificed rats. RESULTS: Oral treatment with 100 - 600 mg/kg/day MECP, for 30 days, resulted in significant (p < 0.05, p < 0.01, p < 0.001) reductions in FPG, TG, TC, LDL-c, VLDL-c in the diabetic rats, effects which were comparable to that of metformin. The extract also caused significant (p < 0.05, p < 0.01) rise in HDL-c values in the alloxan diabetic rats. Phytochemical result showed the presence of alkaloids, flavonoids, cardiac glycosides, tannins and saponin in varying concentrations. The biological effects recorded for the extract could be due to any or a combination of these phytochemical constituents. CONCLUSION: Results of this study lend support to the traditional use of grapefruit seeds in the management of type 1 diabetic patients and may suggest a role in orthodox management of the disease.