The effect of dietary fat, antioxidants, and pro-oxidants on blood lipids, lipoproteins, and atherosclerosis

Lecithin and cardiovascular health: a comprehensive review

BACKGROUND

Cardiovascular diseases are one of the prime causes of mortality globally. Therefore, concerted efforts are made to prevent or manage disruptions from normal functioning of the cardiovascular system. Disruption in lipid metabolism is a major contributor to cardiovascular dysfunction. This review examines how lecithin impacts lipid metabolism and cardiovascular health. It emphasizes lecithin's ability to reduce excess low-density lipoproteins (LDL) while specifically promoting the synthesis of high-density lipoprotein (HDL) particles, thus contributing to clearer understanding of its role in cardiovascular well-being. Emphasizing the importance of lecithin cholesterol acyltransferase (LCAT) in the reverse cholesterol transport (RCT) process, the article delves into its contribution in removing surplus cholesterol from cells. This review aims to clarify existing literature on lipid metabolism, providing insights for targeted strategies in the prevention and management of atherosclerotic cardiovascular disease (ASCVD). This review summarizes the potential of lecithin in cardiovascular health and the role of LCAT in cholesterol metabolism modulation, based on articles from 2000 to 2023 sourced from databases like MEDLINE, PubMed and the Scientific Electronic Library Online.

MAIN BODY

While studies suggest a positive correlation between increased LCAT activities, reduced LDL particle size and elevated serum levels of triglyceride-rich lipoprotein (TRL) markers in individuals at risk of ASCVD, the review acknowledges existing controversies. The precise nature of LCAT's potential adverse effects remains uncertain, with varying reports in the literature. Notably, gastrointestinal symptoms such as diarrhea and nausea have been sporadically documented.

CONCLUSIONS

The review calls for a comprehensive investigation into the complexities of LCAT's impact on cardiovascular health, recognizing the need for a nuanced understanding of its potential drawbacks. Despite indications of potential benefits, conflicting findings warrant further research to clarify LCAT's role in atherosclerosis.

Preventive effect of Caralluma fimbriata against high-fat diet induced injury to heart by modulation of tissue lipids, oxidative stress and histological changes in Wistar rats

OBJECTIVE

To investigate whether hydro-alcoholic extract of aerial parts of Caralluma fimbriata (CFE) could attenuate high-fat diet (HFD) induced cardiac damage.

METHODS

Forty rats were divided into five groups: control (C), treated with CFE, treated with HFD, HFD treated with CFE, and HFD treated with metformin (Met).

RESULTS

CFE treatment significantly (p < .001) attenuated HFD-induced increase in cardiac lipids such as total lipids, triglycerides, total cholesterol, and free fatty acids and decreased phospholipids accompanied by increasing in lipid peroxidation and protein oxidation. Furthermore, significant reduction in the activities of antioxidant enzymes, creatine kinase and aldose reductase and sorbitol dehydrogenase was also observed in HFD fed rats. These changes were alleviated by CFE. Moreover, the histopathological observations of heart are also in agreement with the biochemical findings.

CONCLUSION

The present study confirmed that CFE could be used as adjuvant therapy for preventing or managing high fat diet induced cardiac damage.

Effects of Alcoholic Extracts of Bangladeshi Mangrove Acanthus ilicifolius Linn. (Acanthaceae) Leaf and Stem on Atherogenic Model of Wistar Albino Rats

Acanthus ilicifolius Linn. (Acanthaceae) is a popular mangrove ethnomedicinal plant that cures several ailments, including asthma, diabetes, cancer, and many others. Our experiment was aimed at evaluating the anti-atherogenic effect of A. ilicifolius (leaf and stem) on a high-fat diet-induced atherogenic rat model. Atherosclerosis was developed in 12 weeks. Treatment with the standard drug (3 mg/kg b.w./day, p.o. of Simvastatin), separate doses of methanolic and ethanolic extracts of A. ilicifolius leaf (250 and 500 mg/kg b.w./day, p.o.), and stem (200 and 400 mg/kg b.w./day, p.o.) was subsequently conducted for additional 15 days. The anti-atherogenic effect was evaluated by estimating the change in body weight, systolic blood pressure, and lipid profile. Histopathology of aorta, liver, and kidney of atherogenic models was done for further evaluation. The antioxidant effect of different extracts was performed via DPPH (2,2-diphenyl-1-picrylhydrazyl) assay using ascorbic acid as standard. The anticoagulant effect was determined after 15 days of treatment with the same doses of the plant extracts and the standard Warfarin (2 mg/kg b.w./day, p.o.). When compared with atherogenic control, treatment with A. ilicifolius significantly reduced (p < 0.01) body weight, systolic blood pressure, and serum lipid levels while it elevated HDL (high-density lipoprotein) level in a dose-dependent manner. Moreover, bleeding and clotting time was significantly decreased (p < 0.01) under the treatment of plant extracts. The histopathological data showed considerable improvement in tissue morphology after treatment. Our study evidenced that the alcoholic extracts of A. ilicifolius leaf and stem have anti-atherogenic properties and may be recommended as a potential herbal remedy for preventing cardiovascular diseases.

Economic evaluation of health losses from air pollution in Beijing, China

Aggravated air pollution in Beijing, China has caused serious health concern. This paper comprehensively evaluates the health losses from illness and premature death caused by air pollution in monetary terms. We use the concentration of PM10 as an indicator of the pollution since it constitutes the primary pollutant in Beijing. By our estimation, air pollution in Beijing caused a health loss equivalent to Ұ583.02 million or 0.03 % of its GDP. Most of the losses took the form of depreciation in human capital that resulted from premature death. The losses from premature deaths were most salient for people of either old or young ages, with the former group suffering from the highest mortality rates and the latter group the highest per capital losses of human capitals from premature death. Policies that target on PM10 emission reduction, urban vegetation expansion, and protection of vulnerable groups are all proposed as possible solutions to air pollution risks in Beijing.

Hypolipidemic activity of a hydroalcoholic extract of Cyperus scariosus Linn. root in guinea pigs fed with a high cholesterol diet

Lipid-lowering and antioxidant activities of a hydroalcoholic extract of Cyperus scariosus Linn. root (HCS) were evaluated in guinea pigs fed with a high cholesterol diet. Serum lipid profile (total cholesterol, triglycerides, LDL-C, VLDL-C, and HDL-C), atherogenic indices and serum enzymes (ALT, AST, ALP, LDH, and CK-MB) were performed in each group at 0 days and at the end of 60 days. Histological study of liver and kidney was done in groups 1, 2, 5, 6 and 7. The total phenolic and flavonoid content in HCS and its antioxidant activity were evaluated by the DPPH assay. Both doses of HCS decreased serum lipid profile and atherogenic indices (P < 0.05). HCS has lipid lowering, immunosuppressive and antioxidant properties, and mays have value in atherosclerosis prevention. The higher dose of HCS also reduced serum AST, ALP, and LDH levels and rosuvastatin increased AST and ALP levels (P < 0.05). Histology of the liver showed decreased lipid accumulation and improvement in hepatocytes in HCS-treated animals. The antioxidant activity of HCS may be responsible for its lipid lowering and cytoprotective action. HCS had significant lipid lowering and antioxidant activity, which; may be due to the phenolic compounds. HCS may be a safe and cost effective alternative to current statin therapy for patients with dyslipidaemia.

Monascus purpureus-fermented Thai glutinous rice reduces blood and hepatic cholesterol and hepatic steatosis concentrations in diet-induced hypercholesterolemic rats

BACKGROUND

Red yeast rice (RYR) is a fermented product used as a food supplement to promote blood circulation and lower blood cholesterol levels in eastern Asia. Interestingly, monacolin K is the most active compound in RYR that proved to inhibit HMG-CoA reductase in the cholesterol biosynthesis pathway.

METHODS

The hypocholesterolemic effects of oral administration of Thai RYR, produced by fermentation of Thai glutinous rice (Oryza sativa L. var. Niaw San-pah-tawng) with Monascus purpureus CMU 002U, were determined in normal and hypercholesterolemic rats. The rats were divided into six groups, and fed two different kinds of diet. Groups I-II, normal rats fed with a normal diet (SP-diet), were treated with distilled water (SP-control) and 2.0 g/kg/day of RYR extract (SP-2 g). In Groups III-VI, the rats were rendered hypercholesterolemic by feeding them a high fat and cholesterol diet (HFC-diet), and were treated with distilled water (HFC-control), 1.0 g/kg/day (HFC-1 g), 2.0 g/kg/day (HFC-2 g) of RYR extract, and 5.0 mg/kg/day of rosuvastatin (HFC-rosuvastatin) for 30 days, respectively.

RESULTS

The RYR extract significantly decreased the concentrations of serum total cholesterol and low density lipoprotein cholesterol (LDL-C), atherosclerotic index, LDL-C/HDL-C ratio and hepatic cholesterol levels in both HFC-1 g and HFC-2 g groups (p < 0.05) as compared with the HFC-control group, and with no significant change in high density lipoprotein cholesterol (HDL-C) concentrations among all six groups. The reduction of serum TC and LDL-C also paralleled the observed changes in mRNA expressions of the genes involved in cholesterol biosynthesis and homeostasis in the liver. The hypercholesterolemic rats treated with RYR extract were significantly higher in LDLR and HMGR expression, but lower in CYP7A1 expression when compared to the untreated hypercholesterolemic rats (HFC-control) (p < 0.05). The hepatic injuries in hypercholesterolemic rats were also obviously alleviated by RYR extract.

CONCLUSIONS

The extract of Thai RYR possessed potent hypocholesterolemic and anti-atherogenic activities in diet-induced hypercholesterolemic rats. The possible mechanism involving cholesterol-lowering potential of the extract might contribute to its ability to increase LDL-C endocytosis in hepatocyte and to competitively inhibit HMG-CoA reductase, a key enzyme for cholesterol biosynthesis in liver.

Triolein and trilinolein ameliorate oxidized low-density lipoprotein-induced oxidative stress in endothelial cells

Uptake of oxidized low-density lipoprotein by endothelial cells is a critical step for the initiation of atherosclerosis. Triacylglycerol uptake in these cells is understood to be a part of the process. The present investigation, comparison among the effects of simple acylglycerol, including tristearin, triolein, and trilinolein, upon oxidized low-density lipoprotein -induced oxidative stress was undertaken. Results indicated that trilinolein (78 % ± 0.02) and triolein (90 % ± 0.01) increased cell viability of endothelial cells exposed to oxidized low-density lipoprotein, whereas tristearin decreased the cell viability (55 % ± 0.03) (P < 0.05). Oxidized low-density lipoprotein treatment significantly increased apoptosis (23 %), compared to cells simultaneously exposed to trilinolein (19 %) or triolein (16 %), where apoptosis was reduced (P < 0.05). On the other hand, exposure to tristearin further increased oxidized low-density lipoprotein -induced cell apoptosis (34 %). Treatment with trilinolein or triolein on oxidized low-density lipoprotein -stimulated endothelial cells inhibited the expression of ICAM-1 and E-selectin mRNA. Moreover, both trilinolein and triolein demonstrated a strong antioxidant response to oxidative stress caused by oxidized low-density lipoprotein. Taken together, the results indicate trilinolein and triolein possess anti-inflammatory properties, which are mediated via the antioxidant defense system.

Amelioration of cholesterol induced atherosclerosis by normalizing gene expression, cholesterol profile and antioxidant enzymes by Vigna unguiculata

Cardiovascular diseases, especially atherosclerosis, have found to be the dreadful diseases worldwide and therapeutic interventions using plant sources have wide therapeutic value. Vigna unguiculata (VU) leaves have been used as food and therapeutics. Hence, our study was designed to evaluate the hypolipidemic as well as anti-atherogenic potential of VU leaves in normalizing atherogenic gene expression, cholesterol profile, generation of reactive oxygen species (ROS) and antioxidant enzyme system on cholesterol fed rabbit model. For the study New Zealand white rabbits were randomly divided into four groups of six animals each and experimental period was three months; group -i - ND [normal diet (40 g feed)], group-ii- ND (normal diet) +EAVU [ethyl acetate fraction of Vigna unguiculata (150 mg/kg body weight)], group -iii- ND [normal diet ]+ CFD [cholesterol fed diet (cholesterol 1 % of 40 g feed and cholic acid 0.5 % of 40 g feed)] and group-iv - ND [normal diet] +CFD [cholesterol fed diet ]+EAVU [ethyl acetate fraction of Vigna unguiculata (150 mg/kg body weight)]. Atherosclerosis was induced by feeding the rabbit with cholesterol (1 % of 40 g feed) and cholic acid (0.5 % of 40 g feed). Supplementation of EAVU normalized cholesterol profile, generation of reactive oxygen species (ROS), lipid peroxidation products like thiobarbituric acid reactive substance (TBARS), antioxidant system and important genes of cardiovascular diseases like interleukin-10 (IL 10), paraoxanase-1 (PON I), interleukin-6 (IL 6), and cyclooxygenase-2 (Cox 2) to near normal level as compared with normal diet. The result obtained showed the antioxidant as well as anti-atherogenic potential of Vigna unguiculata leaves in ameliorating cholesterol induced atherosclerosis, and thus it is good task to include VU leaves in daily diet for the prevention of cardiovascular diseases especially atherosclerosis.

Comparative studies of the effects of egg yolk, oats, apple, and wheat bran on serum lipid profile of wistar rats

Excess consumption of egg especially its yolk has been implicated in hyperlipidaemia (high level of cholesterol and triglyceride in the blood). Conversely, soluble dietary fibers, probably due to their ability to bind free lipid molecules, appear to play an important role in protecting against hyperlipidaemia. This study sought to evaluate the comparative effects of selected sources of fibers: apple, oats, and wheat bran, on serum lipid profile in physiologically normal Wistar rats. Twenty rats were used for the study and were randomized into four groups, with each containing five animals (n  =  5). A group which serves as control was fed with egg yolk while the other three groups were fed with apple, oats, and wheat bran, respectively. After two weeks of feeding, the animals were fasted overnight and blood samples from the retro-orbital sinus of the eye were collected for analyses of lipid profile. The results obtained showed that the group fed with oats had the lowest level of total cholesterol (82.9 ± 1.8 mg), low density lipoprotein (LDL) cholesterol (49.3 ± 1.4 mg), and triglycerides (TG) (75.1 ± 1.7 mg), as well as the highest level of HDL cholesterol (33.9 ± 0.9 mg). On the contrary, the group fed with egg yolk showed the highest level of total cholesterol (117.1 ± 4.4 mg), LDL cholesterol (96.4 ± 1.5 mg), and triacylglyceride (109 ± 2.6 mg), as well as the lowest level of HDL cholesterol (18.5 ± 0.9 mg). There was no significant difference (P  <  0.05) between oats and apple in their effects on blood lipid profile of Wistar rats. Wheat bran, being an insoluble dietary fibre, had less significant (P  <  0.05) effect on the blood lipid profile when compared to oats and apple. Findings from this study may assist physicians and dieticians in recommending appropriate diet for individuals desiring to normalize their blood lipids levels.

Hypolipidemic effect of Semecarpus anacardium in high cholesterol fed hypercholesterolemic rats

OBJECTIVE: To evaluate the hypolipidemic effect of Semecarpus anacardium Linn nut milk extract (SA) in high cholesterol fed hyperlipidemic rat model. METHODS: Rats were divided into four groups which included control animals, hypercholesterolemic animals, hypercholesterolemic animals treated with SA (200 mg/kg body weight dissolved in olive oil), and drug control rats. Lipid levels in serum and liver, and lipid metabolising enzymes were determined after treatment. RESULTS: High cholesterol diet significantly (P<0.05) increased the lipid levels in serum and liver and altered the activities of lipid metabolising enzymes. Significant decrease (P<0.05) in plasma and liver lipid levels were observed whereas the drug ameliorated the activities of lipid metabolising enzymes in drug treated groups. CONCLUSIONS: SA demonstrated remarkable hypolipidemic activity in high cholesterol fed hypercholesterolemic rats. The potential antihyperlipidemic action is plausibly due to its underlying antioxidant role.

Trans fat involvement in cardiovascular disease

Coronary heart disease is becoming a worldwide epidemic and diet and lifestyle are well known contributing factors. Identifying the kinds of foods that may have a cardioprotective or cardiotoxic effect and understanding their molecular mechanisms of action has become of increasing importance. Through largely epidemiological evidence, trans fatty acid (TFA) intake has been associated with a variety of cardiovascular complications including atherosclerosis. Traditionally, industrial TFAs (iTFAs) have been associated with these deleterious cardiovascular effects. However, there is a current body of research that suggests that ruminant trans fats (rTFAs) may have a cardioprotective role within the heart. The molecular mechanisms whereby TFAs are delivering their effects are largely unknown. In the following review, we discuss recent in vitro, animal and epidemiological research to better understand the effect of TFAs in the diet on cardiovascular disease, particularly atherosclerosis.

Effect of weight at slaughter and breed on beef intramuscular lipid classes and fatty acid profile

The effect of slaughter weight and breed on the composition of intramuscular fat (IMF) of seven Spanish cattle breeds was studied. Lipid classes and fatty acids were evaluated in young bulls of seven local Spanish cattle breeds, Asturiana, Avileña, Morucha, Parda Alpina, Pirenaica, Retinta and Rubia Gallega, slaughtered at a live weight of 320 kg (veal type) and 550 kg (yearling bull type). Higher slaughter weight and early maturating breeds produced higher IMF content in the longissimus muscle (P < 0.001), which was linked to a reduction in phospholipids, monoglycerides, diglycerides, cholesterol and free-fatty acids content, but an increase in triacylglycerols. Besides, heavier animals displayed a higher percentage of saturated and monounsaturated fatty acids (MUFA), but a lower polyunsaturated fatty acids (PUFA) percentage (P < 0.001). The increase in triglycerides (TG), saturated fatty acids (SFA) and MUFA illustrates the increasing importance of lipid storage as fattening proceeds and the acquisition of ruminal functionality. The feeding system based on cereals had a strong influence on the fatty acid profile, giving the studied beef a relatively high PUFA/SFA and n-6/n-3 ratios.

Plasma selenium, zinc, copper and lipid levels in postmenopausal Turkish women and their relation with osteoporosis

It has been shown that the trace elements and lipids play role in the growth, development and maintenance of bones. We aimed to investigate serum selenium (Se), zinc (Zn), copper (Cu) and lipid (total cholesterol, triglyceride (TG), high density lipoprotein-cholesterol, low-density lipoprotein-cholesterol) levels in postmenopausal women with osteoporosis, osteopenia and in healthy controls, and to determine the relationship between Se, Zn, Cu and lipid parameters and bone mineral density (BMD). The study included 107 postmenopausal women; 35 healthy (group 1), 37 osteopenic (group 2) and 35 osteoporotic (group 3). The women in all three groups were carefully matched for body mass index (BMI). Serum concentrations of Se, Zn and Cu were measured by atomic absorption spectrophotometry. Plasma Se, Cu, Zn and lipid levels were similar in all groups (p > 0.05). When we combined the women in each of the three groups, and considered them as one group (n = 107) we found a positive correlation between BMI and lumbar vertebra BMD, femur neck BMD, femur total BMD; a positive correlation between TG and femur neck BMD, femur total BMD; a positive correlation between Zn and lumbar vertebra BMD (total T score) (p < 0.05). There was no correlation between Se, Cu, Zn, P and lipid parameters (p > 0.05). Although BMI has a positive effect on BMD, trace elements and lipids, except Zn and TG, did not directly and correlatively influence BMD. Further studies are needed to clarify the role and relationship of trace elements and lipid parameters in postmenopausal osteoporosis.

Lipid-lowering and antioxidative activities of aqueous extracts of Ocimum sanctum L. leaves in rats fed with a high-cholesterol diet

The present study was conducted to investigate the lipid-lowering and antioxidative activities of Ocimum sanctum L. (OS) leaf extracts in liver and heart of rats fed with high-cholesterol (HC) diet for seven weeks. The results shows that OS suppressed the high levels of serum lipid profile and hepatic lipid content without significant effects on fecal lipid excretion. Fecal bile acids excretion was increased in HC rats treated with OS. The high serum levels of TBARS as well as AST, ALT, AP, LDH, CK-MB significantly decreased in HC rats treated with OS. OS suppressed the high level of TABARS and raised the low activities of GPx and CAT without any impact on SOD in the liver. As for the cardiac tissues, OS lowered the high level of TABARS, and raised the activities of GPx, CAT, and SOD. Histopathological results show that OS preserved the liver and myocardial tissues. It can be concluded that OS leaf extracts decreased hepatic and serum lipid profile, and provided the liver and cardiac tissues with protection from hypercholesterolemia. The lipid-lowering effect is probably due to the rise of bile acids synthesis using cholesterol as precursor, and antioxidative activity to protect liver from hypercholesterolemia.

Major dietary patterns and their associations with cardiovascular risk factors among women in West Bengal, India

Few studies have examined dietary patterns in relation to cardiovascular risk factors in Asian populations, particularly in India. The present study was undertaken to explore dietary patterns in a general urban Bengalee population of women in West Bengal, India, and their association with cardiovascular risk factors. We performed a cross-sectional study of 701 women (aged 35 years and above) selected by cluster sampling from twelve different wards of the Kolkata Municipal Corporation (Kolkata, India). The following three major dietary patterns were identified: the 'vegetable, fruits and pulses' pattern (characterised by higher intakes of dark-yellow and green leafy vegetables, sweets, fruits, pulses, nuts, poultry and eggs, and lower intake of mustard oil); the 'hydrogenated and saturated fat and vegetable oil' pattern (characterised by higher intakes of butter, hydrogenated oil, ghee, vegetable oil, mustard oil, condiments, sweets, fish, high-fat dairy and refined grain); the 'red meat and high-fat dairy' pattern (characterised by higher intakes of red meat, high-fat dairy products, whole grain, high-energy drinks and condiments, and lower intakes of fish, refined grain and low-fat dairy products). The vegetable, fruits and pulses pattern was inversely associated with serum total cholesterol (TC), LDL-cholesterol and non-HDL-cholesterol (HDL-C) concentrations (P < 0·05 for all). The hydrogenated and saturated fat and vegetable oil pattern was positively associated with BMI, waist circumference (WC) and HDL-C concentration (P < 0·05 for all). In this Bengalee population, these three major dietary patterns were observed, and the dietary patterns were independently associated with BMI, WC and serum TC concentrations in women.

Hypolipidemic effect of MeOH extract of Bambusae Caulis in Taeniam in hyperlipidemia induced by Triton WR-1339 and high cholesterol diet in rats

Hyperlipidemia has been implicated in atherosclerosis which is the leading cause of death among world population and resulting from lipid metabolic changes is a major cause of atherosclerosis. Bambusae Caulis in Taeniam belongs to Bambusaceae is the stem of Phyllostachys nigra (Lodd.) Munro var. henonis (Bean) Stapf of Phyllostachys bambusoides Siebold et Zuccarini, the perennial evergreen tree. The green middle layer of stem is dried in string-shape I shadow after the bark had been removed. In this study, the effects of middle layer of PN, PB, PP, and BCT on rat with hyperlipidemia, induced by Triton WR-1339 and high cholesterol diet were investigated. We measured plasma levels of triglyceride, total cholesterol, low-density lipoprotein (LDL)-cholesterol, and high-density lipoprotein (HDL)-cholesterol as measure of its hyperlipidemic effects. As a result, all of the Bambusae Caulis in Taeniam was reduced total cholesterol, LDL. Inhibition rate on LDL-oxidation, hACAT-1, and hACAT-2 was increased dose-dependently. Therefore all of the Bambusae Caulis in Taeniam is a good candidate for the treatment on Triton WR-1339 and high cholesterol diet-induced blood circulatory disorders, obesity, and hyperlipidemia.

Antioxidant Activity and Lipid-Lowering Effect of Essential Oils Extracted from Ocimum sanctum L. Leaves in Rats Fed with a High Cholesterol Diet

It has been reported that Ocimum sanctum L. (OS) leaves decrease serum lipid profile in normal and diabetic animals. No experimental evidences support the anti-hyperlipidemic and antioxidative actions against hypercholesterolemia. Moreover the identity of the specific chemical ingredients in OS leaves responsible for these pharmacological effects are unknown. Since OS leaves are rich in essential oil (EO). Therefore the present study was conducted to investigate the anti-hyperlipidemic and antioxidative activities of EO extracted from OS leaves in rats fed with high cholesterol (HC) diet. EO was extracted by the hydrodistillation method and the chemical constituents were then identified by Gas Chromatography-Mass Spectrometry. The experiment was performed in Male Wistar rats fed with 2.5 g%(w/w) of cholesterol diet for seven weeks. During the last 3 weeks, rats were daily fed with EO. The results showed that phenyl propanoid compounds including eugenol and methyl eugenol were the major constituents of EO. EO suppressed the high serum lipid profile and atherogenic index as well as serum lactate dehydrogenase and creatine kinase MB subunit without significant effect on high serum levels of aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase in rats fed with HC diet. In addition, EO was found to decrease the high levels of thiobarbituric acid reactive substances (TBARS), glutathione peroxidase (GPx) and superoxide dismutase (SOD) without impacting catalase (CAT) in the cardiac tissue while in the liver, it decreased high level of TBARS without significantly effecting GPx, SOD and CAT. Histopathological results confirmed that EO preserved the myocardial tissue. It can be concluded that EO extracted from OS leaves has lipid-lowering and antioxidative effects that protect the heart against hypercholesterolemia. Eugenol that is contained in EO likely contribute to these pharmacological effects.

Influence of soy lecithin administration on hypercholesterolemia

Recent studies suggest that lecithin-rich diet can modify cholesterol homeostasis and hepatic lipoprotein metabolism. Considering the phytotherapeutic impact of lecithin, this work hypothesizes that lecithin administration in hypercholesterolemic patients may reduce cholesterol concentrations by increasing biliary secretion. Total cholesterol and LDL were evaluated after soy lecithin administration in hypercholesterolemic patients. One soy lecithin capsule (500 mg/RP-Sherer) was administrated daily. One-two months before the treatment beginning, blood samples were collected for total lipids and cholesterol fractions analysis. The results showed a reduction of 40.66% and 42.00% in total cholesterol and of 42.05% and 56.15% in LDL cholesterol after treatment for one and two months, respectively. A significant reduction in total cholesterol and LDL-cholesterol concentrations was observed during the first month of treatment, suggesting that the administration of soy lecithin daily may be used as a supplemental treatment in hypercholesterolemia.

Hypocholesterolemic effect of stilbenes containing extract-fraction from Cajanus cajan L. on diet-induced hypercholesterolemia in mice

Cajanus cajan (L) is a natural plant which contains a lot of potential active components. In the present study, we identified the effects of the stilbenes containing extract-fraction from Cajanus cajan L (sECC) on diet-induced (for 4 weeks) hypercholesterolemia in Kunming mice. All experimental mice were divided into 5 groups: control group, model group, sECC-treated with 200 or 100 mg/kg/day, and simvastatin group. The effects of sECC were investigated by monitoring serum and liver lipid profile (cholesterol homeostasis and triglyceride) as well as serum superoxide dismutase activity in those mice. To further explore the mechanism of sECC, hepatic 3-hydroxy-3-methylglutaryl-CoA reductase (HMG-CoA reductase), cholesterol 7α-hydroxylase (CYP7A1), and low density lipoprotein receptor (LDL receptor) expressions in cholesterol homeostasis were analyzed by reverse transcription PCR. After 4 weeks pretreatment, compared with model group, the increased serum and hepatic total cholesterol were markedly attenuated by sECC (200 mg/kg) by 31.4% and 22.7% (p<0.01), respectively, the triglyceride levels of serum and liver were also lowered by 22.98% and 14.39%, respectively. At the same time, serum LDL cholesterol decreased by 52.8% (p<0.01) accompanied with the activities of serum superoxide dismutase increased by 20.98%. Atherogenic index and body weight were also reduced markedly. The mRNA expressions of HMG-CoA reductase, CYP7A1, and LDL-receptor were significantly enhanced in the mice administered with sECC (200 mg/kg/day), whereas those expressions were suppressed by the hypercholesterolemic diet. These data indicate that sECC reduces the atherogenic properties of dietary cholesterol in mice. Its hypocholesterolemic effect may involve enhancement of the hepatic LDL-receptor and cholesterol 7alpha-hydroxylase expression levels and bile acid synthesis.

Melatonin prevents oxidized low-density lipoprotein-induced increase of myosin light chain kinase activation and expression in HUVEC through ERK/MAPK signal transduction

Melatonin, the main secretary product of the pineal gland, is potentially effective in the prevention of a number of diseases in which free radical processes are involved. The development of hypercholesterolemia is a multifactorial process in which elevated oxidized low-density lipoprotein (ox-LDL) levels play a central role. The purpose of this study was to test whether melatonin prevents ox-LDL-induced increase of myosin light chain kinase (MLCK) activation and expression in human umbilical vein endothelial cells (HUVECs) through extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK) signal transduction. HUVEC were cultured in vitro and treated with ox-LDL, melatonin, and PD98059 (a selective inhibitor of ERK), respectively. The expression, transcription, and activity of MLCK were measured by western blot, immunohistochemistry, reverse transcription-polymerase chain reaction and gamma-(32)P-adenosine triphosphate (ATP) incorporation, respectively. The results showed that the expression and activity of MLCK were increased in ox-LDL-treated HUVECs and this was decreased by melatonin and PD98059. The expression and activity of MLCK induced by ox-LDL was associated with the phosphorylation of ERK. These results indicate for the first time that hypercholesterolemia may be associated with MLCK expression and the activity which can be reduced by melatonin through ERK/MAPK signal transduction.

Associations of blood selenium and serum lipid levels in Japanese premenopausal and postmenopausal women

OBJECTIVE

The purpose of this study was to investigate whether the level of selenium in serum or the level of selenium in erythrocytes (E-Se) was associated with serum lipid parameters (total cholesterol [TC], triglycerides, and high-density and low-density lipoprotein cholesterol [LDL-C]) in pre- and postmenopausal women.

DESIGN

Healthy female workers aged 35 to 60 years were recruited, and TC, triglycerides, high-density lipoprotein cholesterol, LDL-C, E-Se, and serum-Se levels were measured in 68 premenopausal and 59 postmenopausal women after excluding those who were treated for hyperlipidemia, receiving hormone therapy, had previous gynecological surgeries, or had irregular menstrual cycles. Information on these women, such as smoking status, current status of menstruation, and current or previous medical treatments, was obtained from a self-administered questionnaire. Correlation analyses and stepwise multiple regression analysis were applied to reveal the interrelationship between serum lipids and Se levels after adjusting for age, body mass index, smoking, and menopause status.

RESULTS

Postmenopausal women had significantly higher levels of TC, triglycerides, and LDL-C and lower levels of E-Se than premenopausal women. TC and LDL-C levels after menopause correlated negatively with E-Se. These associations were also statistically significant after controlling for age, smoking status, and body mass index. E-Se was selected as a significant related variable to explain TC and LDL-C levels as well as body mass index by multiple regression analysis.

CONCLUSION

E-Se may be one of the possible associated factors that decrease the levels of TC and LDL-C after menopause. Further studies are needed to clarify the cause-and-effect relationship of nutritional Se status and lipid profile.

Lipid-lowering effects of methanolic extract of Vernonia amygdalina leaves in rats fed on high cholesterol diet

We investigated the lipid-lowering effects of methanolic extract of Vernonia amygdalina (VA) leaves in rats fed an high cholesterol diet, and compared with a standard hypolipidemic drug, Questran (Qu). The effects of VA on the lipid profile were assessed by measuring the levels of total cholesterol, triglyceride, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, lipid peroxidation (LPO), phospholipid, and glutathione (GSH) in the plasma and liver of the rats. Administration of cholesterol at a dose of 30 mg/0.3 ml, five times in a week for nine consecutive weeks resulted in a significant increase (p < 0.05) in plasma and post mitochondrial fraction (PMF) cholesterol levels by 33% and 55%, respectively. However, treatment with extract of VA at doses of 100 and 200 mg/kg caused a dose dependent reduction in the plasma and PMF cholesterol by 20%, 23% and 23%, 29%, respectively. Similar reduction in cholesterol levels was obtained in Qu-treated rats. Furthermore, VA at 200 mg/kg decreased the plasma and PMF LDL-cholesterol levels by 23% and 49%, and also decreased plasma and PMF triglyceride levels by 29% and 28%, respectively. Also, VA at 100 and 200 mg/kg caused a dose-dependent increase in plasma HDL-cholesterol levels by 41% and 59%, respectively. However, there were no significant differences (p > 0.05) in the PMF HDL-cholesterol and phospholipid levels of the treated rats when compared to hypercholesterolemic rats. There were significant decreases (p < 0.05) in the LPO levels of extract-treated rats. Precisely, VA at 100 and 200 mg/kg decreased the levels of plasma and PMF LPO by 38%, 42% and 35%, 45%, respectively. In addition, VA augmented the cholesterol-induced decrease in PMF glutathione levels of the rats. Taken together, these results suggest the lipid-lowering effects of VA and, probably serve as a new potential natural product for the treatment of hyperlipidemia.

Hypolipidemic effect of Telfairia occidentalis (fluted pumpkin) in rats fed a cholesterol-rich diet

Telfairia occidentalis (fluted pumpkin) is one of the commonly consumed leafy vegetables in Nigeria. In order to justify its inclusion in herbal preparations in African traditional medicine, the possible hypolipidemic effect of this vegetable was investigated in rats fed a cholesterol-rich diet. The ability of Questran, a hypolipidemic drug, to attenuate hypercholesterolemia was also examined. Rats were fed with either a basal diet containing cholic acid (0.2%) or a supplemented diet with T. occidentalis at the 3% and 6% levels. Oral administration of cholesterol for 9 consecutive weeks resulted in a significant increase (P < .001) in the relative weight of the heart of cholesterol-fed rats. However, supplemented diets significantly (P < .001) ameliorated the cholesterol-induced enlargement of the heart. Rats fed on supplemented diets had a dose-dependent reduction in plasma and postmitochondrial supernatant fraction (PMF) cholesterol levels. In particular, supplemented diets containing 3% and 6% T. occidentalis decreased plasma and PMF cholesterol levels by 20% and 30% and by 30% and 45%, respectively. A similar decrease in plasma and PMF cholesterol levels was obtained in Questran-treated hypercholesterolemic rats. Furthermore, 3% and 6% T. occidentalis-supplemented diets significantly (P < .05) decreased the cholesterol-induced increase in plasma and PMF low-density lipoprotein (LDL) cholesterol levels by 24% and 48% and by 28% and 52%, respectively. In contrast, there was no significant difference (P > .05) in plasma and PMF triglyceride levels of rats fed on supplemented diets when compared with cholesterol-fed rats. There were significant decreases (P < .05) in lipid peroxidation levels in rats fed on the supplemented diets. Specifically, 3% and 6% T. occidentalis-supplemented diets decreased plasma and PMF lipid peroxidation by 24% and 20% and by 42% and 21%, respectively. This study demonstrates that T. occidentalis may be a useful therapy for hypercholesterolemia through reducing oxidative stress and cholesterol levels.

Fatty acid composition of habitual omnivore and vegetarian diets

High-fat diets are implicated in the onset of cardiovascular disease (CVD), cancer, and obesity. Large intakes of saturated and trans FA, together with low levels of PUFA, particularly long-chain (LC) omega-3 (n-3) PUFA, appear to have the greatest impact on the development of CVD. A high n-6:n-3 PUFA ratio is also considered a marker of elevated risk of CVD, though little accurate data on dietary intake is available. A new Australian food composition database that reports FA in foods to two decimal places was used to assess intakes of FA in four habitual dietary groups. Analysis using the database found correlations between the dietary intakes of LC n-3 PUFA and the plasma phospholipid LC n-3 PUFA concentrations of omnivore and vegetarian subjects. High meat-eaters (HME), who consumed large amounts of food generally, had significantly higher LC n-3 PUFA intakes (0.29 g/d) than moderate meat-eaters (MME) (0.14 g/d), whose intakes in turn were significantly higher than those of ovolacto-vegetarians or vegans (both 0.01 g/d). The saturated FA intake of MME subjects (typical of adult male Australians) was not different from ovolacto-vegetarian intakes, whereas n-6:n-3 intake ratios in vegetarians were significantly higher than in omnivores. Thus, accurate dietary and plasma FA analyses suggest that regular moderate consumption of meat and fish maintains a plasma FA profile possibly more conducive to good health.

The protective role of Chinese prescription Kangen-karyu extract on diet-induced hypercholesterolemia in rats

This study was carried out to investigate the protective potential of Chinese prescription Kangen-karyu, comprising six crude drugs, on coronary heart disease which is the principal cause of morbidity and mortality worldwide. The diet-induced hypercholesterolemic rat model, which shows an elevation in low density lipoprotein (LDL) cholesterol and atherosclerosis, was employed. The control rats fed a diet of 1% cholesterol and 0.5% cholic acid showed the highest cholesterol levels in serum and feces relative to those fed a normal diet, however, the rats administered Kangen-karyu extract showed reductions in these levels without changes in liver cholesterol, indicating that the reduction of serum total cholesterol by Kangen-karyu extract probably arises from an increase in cholesterol excretion. Furthermore, the administration of Kangen-karyu extract significantly prevented the elevation of serum aspartate aminotransferase and alanine aminotransferase, known as marker enzymes of liver damage. The elevated serum levels of LDL cholesterol were lowered, however, the high density lipoprotein cholesterol level was significantly elevated by Kangen-karyu extract and these were dose-dependent decreases in the atherogenic index to 15.2, 8.8 and 7.5 at oral doses of 50, 100 and 200 mg from the 19.4 control value, respectively. In addition, Kangen-karyu extract inhibited LDL oxidation in a dose-dependent manner, and the elevated level of thiobarbituric acid-reactive substances in control rats showed a decline by the administration of Kangen-karyu extract. The present study suggests that Kangen-karyu could play a protective role against hypercholesterolemia through the regulation of cholesterol levels and inhibition of lipid peroxidation.

Plant sterols as dietary adjuvants in the reduction of cardiovascular risk: theory and evidence

Plant sterol-enriched foods are an effective dietary adjuvant in reducing cardiovascular risk by lowering total cholesterol and low density lipoprotein-cholesterol (LDL-C) in serum by up to approximately 15%. The mechanism of action of plant sterols is different from those of 3-hydroxy-3-methylglutaryl coenzyme A inhibitors (statins) and thus their effect is additive. Combining plant sterols with other dietary components known to reduce cholesterol in a portfolio approach has proven to be most effective for reduction of hypercholesterolemia and provide an alternative treatment option for clinicians. Plant sterol-enriched foods provides clinicians with a relatively cheap, safe, and effective way to help patients manage their cardiovascular risk.

The postprandial effects of dietary antioxidants in humans

Traditional risk factors as measured in the fasted individual are reported to be responsible for the prediction of only half of the incident cases of cardiovascular disease. However, many complex and deleterious reactions occur in the postprandial state. The consequences of oxidative reactions occurring during this time represent major risk for fatal and nonfatal heart disease, ischemia, and stroke, and include oxidative modifications to low-density lipoproteins (LDL), decreased production and bioactivity of nitric oxide (NO) in endothelial cells, and reduced endothelial function. Supplementation with antioxidants may prevent or reduce many of these risks. Antioxidants have been shown to reduce oxidative modification to LDL cholesterol, prevent glucose auto-oxidation, improve the bioactivity of NO, and attenuate or prevent the decrease in endothelial function associated with the postprandial state. Because many nonfasting reactions represent major risk for disease, postprandial risk analysis must form a larger part of the diagnostic strategy for disease prevention in the future.

Response of obligate heterozygotes for phytosterolemia to a low-fat diet and to a plant sterol ester dietary challenge

Twelve obligate heterozygotes from two kindreds were ascertained through phytosterolemic probands homozygous for molecular defects in the ATP binding cassette (ABC) half transporter, ABCG8. The response of these heterozygotes to a Step 1 diet low in fat, saturated fat, and cholesterol, and to 2.2 g daily of plant sterols (as esters) was determined in Protocol I (16 weeks) and Protocol II (28 weeks) during three consecutive feeding periods: Step 1/placebo spread; Step 1/plant sterol spread; and Step 1/placebo spread (washout). At baseline, half the heterozygotes had moderate dyslipidemia and one-third had mildly elevated campesterol and sitosterol levels. On the Step 1/placebo spread, mean LDL cholesterol decreased significantly, 11.2% in Protocol I (n = 12), and 16.0% in Protocol II (n = 7). Substitution with plant sterol spread produced a significant treatment effect on LDL levels in Protocols I and II. Conversely, the mean levels of campesterol and sitosterol increased 119% and 54%, respectively, during the use of plant sterol spread for 6 weeks in Protocol I, an effect mirrored for 12 weeks in Protocol II. During the placebo spread washouts, LDL levels increased, while those of plant sterols decreased to baseline levels in both protocols. In conclusion, phytosterolemic heterozygotes respond well to a Step 1 diet, and their response to a plant sterol ester challenge appears similar to that observed in normals.

Honey with high levels of antioxidants can provide protection to healthy human subjects

Free radicals and reactive oxygen species (ROS) have been implicated in contributing to the processes of aging and disease. Humans protect themselves from these damaging compounds, in part, by absorbing antioxidants from high-antioxidant foods. This report describes the effects of consuming 1.5 g/kg body weight of corn syrup or buckwheat honey on the antioxidant and reducing capacities of plasma in healthy human adults. The corn syrup treatment contained 0.21 +/- 0.06 mg of phenolic antioxidants per gram, and the two buckwheat honey treatments contained 0.79 +/- 0.02 and 1.71 +/- 0.21 mg of phenolic antioxidants per gram. Following consumption of the two honey treatments, plasma total-phenolic content increased (P < 0.05) as did plasma antioxidant and reducing capacities (P < 0.05). These data support the concept that phenolic antioxidants from processed honey are bioavailable, and that they increase antioxidant activity of plasma. It can be speculated that these compounds may augment defenses against oxidative stress and that they might be able to protect humans from oxidative stress. Given that the average sweetener intake by humans is estimated to be in excess of 70 kg per year, the substitution of honey in some foods for traditional sweeteners could result in an enhanced antioxidant defense system in healthy adults.

The effects of Coptidis Rhizoma extract on a hypercholesterolemic animal model

The serum cholesterol (total, free, esterified, low density lipoprotein (LDL) and oxidized LDL) levels of rats fed a diet containing, by weight, 1% cholesterol and 0.5% cholic acid increased, as compared with those of rats fed a normal diet. The levels, especially of total cholesterol, LDL and oxidized LDL, were reduced significantly in a dose-dependent manner, in rats given Coptidis Rhizoma extract orally at doses of 50 and 100 mg/kg body wt./day for 30 days. These results indicate that Coptidis Rhizoma extract is effective in reducing the pathological damage caused by hypercholesterolemia, through lowering of serum cholesterol levels. In addition, Coptidis Rhizoma extract reduced the level of liver cholesterol, but it did not reduce that of fecal cholesterol, suggesting that the cholesterol level-lowering effect resulted from the reduction of cholesterol synthesis, not the enhancement of its excretion. Furthermore, the serum thiobarbituric acid-reactive substance level decreased after oral administration of Coptidis Rhizoma extract, indicating that Coptidis Rhizoma could prevent hypercholesterolemic disease through reducing lipid peroxidation. This study demonstrates that Coptidis Rhizoma may be a useful therapy for hypercholesterolemia through reducing oxidative stress and cholesterol levels.

Consumption of dairy products in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort: data from 35 955 24-hour dietary recalls in 10 European countries

OBJECTIVES

To describe and compare the consumption of dairy products in cohorts included in the European Prospective Investigation into Cancer and Nutrition (EPIC).

METHODS

Data from single 24-hour dietary recall interviews collected through a highly standardised computer-based program (EPIC-SOFT) in 27 redefined centres in 10 European countries between 1995 and 2000. From a total random sample of 36 900, 22 924 women and 13 031 men were selected after exclusion of subjects under 35 and over 74 years of age.

RESULTS

A high total consumption of dairy products was reported in most of the centres in Spain and in the UK cohort sampled from the general population, as well as in the Dutch, Swedish and Danish centres. A somewhat low consumption was reported in the Greek centre and in some of the Italian centres (Ragusa and Turin). In all centres and for both sexes, milk constituted the dairy sub-group with the largest proportion (in grams) of total dairy consumption, followed by yoghurt and other fermented milk products, and cheese. Still, there was a wide range in the contributions of the different dairy sub-groups between centres. The Spanish and Nordic centres generally reported a high consumption of milk, the Swedish and Dutch centres reported a high consumption of yoghurt and other fermented milk products, whereas the highest consumption of cheese was reported in the French centres.

CONCLUSION

The results demonstrate both quantitative and qualitative disparities in dairy product consumption among the EPIC centres. This offers a sound starting point for analyses of associations between dairy intake and chronic diseases such as cancer.

Clinical relevance of the biochemical, metabolic, and genetic factors that influence low-density lipoprotein heterogeneity

Traditional risk factors for coronary artery disease (CAD) predict about 50% of the risk of developing CAD. The Adult Treatment Panel (ATP) III has defined emerging risk factors for CAD, including small, dense low-density lipoprotein (LDL). Small, dense LDL is often accompanied by increased triglycerides (TGs) and low high-density lipoprotein (HDL). An increased number of small, dense LDL particles is often missed when the LDL cholesterol level is normal or borderline elevated. Small, dense LDL particles are present in families with premature CAD and hyperapobetalipoproteinemia, familial combined hyperlipidemia, LDL subclass pattern B, familial dyslipidemic hypertension, and syndrome X. The metabolic syndrome, as defined by ATP III, incorporates a number of the components of these syndromes, including insulin resistance and intra-abdominal fat. Subclinical inflammation and elevated procoagulants also appear to be part of this atherogenic syndrome. Overproduction of very low-density lipoproteins (VLDLs) by the liver and increased secretion of large, apolipoprotein (apo) B-100-containing VLDL is the primary metabolic characteristic of most of these patients. The TG in VLDL is hydrolyzed by lipoprotein lipase (LPL) which produces intermediate-density lipoprotein. The TG in intermediate-density lipoprotein is hydrolyzed further, resulting in the generation of LDL. The cholesterol esters in LDL are exchanged for TG in VLDL by the cholesterol ester tranfer proteins, followed by hydrolysis of TG in LDL by hepatic lipase which produces small, dense LDL. Cholesterol ester transfer protein mediates a similar lipid exchange between VLDL and HDL, producing a cholesterol ester-poor HDL. In adipocytes, reduced fatty acid trapping and retention by adipose tissue may result from a primary defect in the incorporation of free fatty acids into TGs. Alternatively, insulin resistance may promote reduced retention of free fatty acids by adipocytes. Both these abnormalities lead to increased levels of free fatty acids in plasma, increased flux of free fatty acids back to the liver, enhanced production of TGs, decreased proteolysis of apo B-100, and increased VLDL production. Decreased removal of postprandial TGs often accompanies these metabolic abnormalities. Genes regulating the expression of the major players in this metabolic cascade, such as LPL, cholesterol ester transfer protein, and hepatic lipase, can modulate the expression of small, dense LDL but these are not the major defects. New candidates for major gene effects have been identified on chromosome 1. Regardless of their fundamental causes, small, dense LDL (compared with normal LDL) particles have a prolonged residence time in plasma, are more susceptible to oxidation because of decreased interaction with the LDL receptor, and enter the arterial wall more easily, where they are retained more readily. Small, dense LDL promotes endothelial dysfunction and enhanced production of procoagulants by endothelial cells. Both in animal models of atherosclerosis and in most human epidemiologic studies and clinical trials, small, dense LDL (particularly when present in increased numbers) appears more atherogenic than normal LDL. Treatment of patients with small, dense LDL particles (particularly when accompanied by low HDL and hypertriglyceridemia) often requires the use of combined lipid-altering drugs to decrease the number of particles and to convert them to larger, more buoyant LDL. The next critical step in further reduction of CAD will be the correct diagnosis and treatment of patients with small, dense LDL and the dyslipidemia that accompanies it.

Oxidized omega-3 fatty acids in fish oil inhibit leukocyte-endothelial interactions through activation of PPAR alpha

Omega-3 fatty acids, which are abundant in fish oil, improve the prognosis of several chronic inflammatory diseases although the mechanism for such effects remains unclear. These fatty acids, such as eicosapentaenoic acid (EPA), are highly polyunsaturated and readily undergo oxidation. We show that oxidized, but not native unoxidized, EPA significantly inhibited human neutrophil and monocyte adhesion to endothelial cells in vitro by inhibiting endothelial adhesion receptor expression. In transcriptional coactivation assays, oxidized EPA potently activated the peroxisome proliferator-activated receptor alpha (PPAR alpha), a member of the nuclear receptor family. In vivo, oxidized, but not native, EPA markedly reduced leukocyte rolling and adhesion to venular endothelium of lipopolysaccharide (LPS)-treated mice. This occurred via a PPAR alpha-dependent mechanism because oxidized EPA had no such effect in LPS-treated PPAR alpha-deficient mice. Therefore, the beneficial effects of omega-3 fatty acids may be explained by a PPAR alpha-mediated anti-inflammatory effect of oxidized EPA.

Vitamin C and the risk of preeclampsia--results from dietary questionnaire and plasma assay

BACKGROUND

Oxidative stress plays an important role in the pathophysiology of preeclampsia.

METHODS

In a case-control study of 109 women with preeclampsia and 259 controls, maternal dietary and plasma vitamin C in relation to preeclampsia risk were assessed. Dietary intake during the periconceptional period and pregnancy was ascertained using a semiquantitative food frequency questionnaire. Logistic regression procedures were used to derive odds ratios (OR) and 95% confidence intervals (CI). Plasma ascorbic acid was determined using automated enzymatic procedures.

RESULTS

After adjusting for maternal age, parity, prepregnancy body mass index, and energy intake, women who consumed <85 mg of vitamin C daily (below the recommended dietary allowance), as compared with others, experienced a doubling in preeclampsia risk (OR = 2.1; 95% CI = 1.1-3.9). The OR for extreme quartiles of plasma ascorbic acid (<42.5 vs > or = 63.3 micromol/liter) was 2.3 (95% CI = 1.1-4.6). Compared with women in the highest quartile, those with plasma ascorbic acid <34.6 micromol/liter (lowest decile) experienced a 3.8-fold increased risk of preeclampsia (95% CI = 1.7-8.8).

CONCLUSIONS

Our results, if confirmed, would suggest that current public health efforts to increase intake of fruits and vegetables rich in vitamin C and other antioxidants may reduce the risk of preeclampsia.

Role of weight loss and polyunsaturated fatty acids in improving metabolic fitness in moderately obese, moderately hypertensive subjects

OBJECTIVE

While the exact regulatory interactions between blood pressure (BP) and obesity are not completely understood, weight loss provides an alternative to pharmacological treatment of hypertension. The intent of this repeated measures study of mild-moderate hypertensive, moderately obese subjects (34 females/18 males) was to determine if the reduction in BP following weight loss could be further affected by modifying the fatty acid (FA) composition of the hypocaloric diet.

METHODS

BP, insulin sensitivity (Si), and lipid parameters were assessed before and after a 10-week calorie-restricted period. Subjects were randomized to one of three dietary groups differing in FA composition. Reduced body weight was maintained for a further 4 weeks and body composition assessment, BP and heart rate measurements were repeated.

RESULTS

Weight loss (10%) in obese hypertensive subjects resulted in substantial improvements in BP, Si and lipid profile. There was no additional effect on the reduction in BP by the type of FA consumed in the diet. Following weight loss, there was a trend for omega-3 FAs to have a protective effect on fat-free mass loss (compared to omega-6 FA Group and saturated FA Group) and a trend to further enhance Si. There were significant improvements in circulating lipid profiles independent of the dietary FA intervention following the weight loss. The improvements in BP and body composition were maintained during the weight-loss maintenance period. The type of fat consumed had minor differential effects on some of the measured metabolic outcomes.

CONCLUSION

These results provide strong support for modest weight loss as a treatment for hypertension.

Dialysis and gel filtration of isolated low density lipoproteins do not cause a significant loss of low density lipoprotein tocopherol and carotenoid concentration

The resistance of isolated low density lipoprotein (LDL) to copper-initiated oxidation is often used as a measure of effectiveness of an antioxidant intervention. Prior to oxidation, excess salt and EDTA are removed via dialysis or gel filtration of the LDL sample. However, there is concern over whether the antioxidant content of dialyzed or gel-filtered LDL is truly representative of native LDL extracted from a blood sample. Previously, the experiments done after the storage of native and dialyzed LDL at -80 degrees C showed that the dialysis step can cause a loss of up to 60% in the tocopherol and carotenoid content of LDL. In the present study, a comparison of the micronutrient concentration in freshly prepared dialyzed and native LDL from 35 subjects showed that after the correction for cholesterol, only lycopene (13%, P < 0.001) and to a lesser extent alpha-carotene (8%, P < 0.02) were significantly decreased, and the absolute fall in concentration was far smaller than previously reported. Other experiments done with smaller numbers of samples suggested that there were minimal micronutrient losses following gel filtration and that it was important to include 10 micromol/L EDTA in the dialysis and elution buffer; otherwise micronutrient losses did occur. In summary, immediate dialysis of freshly isolated LDL in the presence of 10 micromol/L EDTA does not cause any major loss in the concentration of tocopherol and most carotenoids.