ascorbic-acid and Hyperlipidemias

Randomised controlled trials (RCTs) in humans revealed contradictory results regarding the effect of vitamin C supplementation on blood lipids. We aimed to conduct a systematic review and meta-analysis of RCTs investigating the effect of vitamin C supplementation on total cholesterol, low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C) and triglycerides and to determine whether the effects are modified by the participants' or intervention characteristics.. Four databases (PubMed, Embase, Scopus and Cochrane Library) were searched from inception until August 2014 for RCTs supplementing adult participants with vitamin C for ≥ 2 weeks and reporting changes in blood lipids.. Overall, vitamin C supplementation did not change blood lipids concentration significantly. However, supplementation reduced total cholesterol in younger participants (≤52 years age) (-0.26 mmol/L, 95% CI: -0.45, -0.07) and LDL-C in healthy participants (-0.32 mmol/L, 95% CI: -0.57, -0.07). In diabetics, vitamin C supplementation reduced triglycerides significantly (-0.15 mmol/L, 95% CI: -0.30, -0.002) and increased HDL-C significantly (0.06 mmol/L, 95% CI: 0.02, 0.11). Meta-regression analyses showed the changes in total cholesterol (β: -0.24, CI: -0.36, -0.11) and in triglycerides (β: -0.17, CI: -0.30, -0.05) following vitamin C supplementation were greater in those with higher concentrations of these lipids at baseline. Greater increase in HDL-C was observed in participants with lower baseline plasma concentrations of vitamin C (β: -0.002, CI: -0.003, -0.0001).. Overall, vitamin C supplementation had no significant effect on lipid profile. However, subgroup and sensitivity analyses showed significant reductions in blood lipids following supplementation in sub-populations with dyslipidaemia or low vitamin C status at baseline. PROSPERO Database registration: CRD42014013487, http://www.crd.york.ac.uk/prospero/.

Topics: Antioxidants; Ascorbic Acid; Ascorbic Acid Deficiency; Cardiovascular Agents; Cardiovascular Diseases; Dyslipidemias; Humans; Hyperlipidemias; Hypolipidemic Agents; Oxidative Stress; Randomized Controlled Trials as Topic; Reproducibility of Results; Risk

This review gives a brief overview of the main types of dementia and summarizes current thinking on the relationship between nutritional-related factors and disorders, and dementia. Dementia is a multi-factor pathological condition, and nutrition is one factor that may play a role on its onset and progression. An optimal intake of nutrients doesn't protect people from dementia. However, studies in this area show that inadequate dietary habits, which are of particular concern in elderly populations, may increase the risk of developing a number of age-related diseases, including disorders of impaired cognitive function. They show that a deficiency in essential nutrients, such as certain B complex vitamins, can result in hyperhomocysteinemia, a well-known risk factor for atherosclerosis and recently associated with cognitive impairment in old age. A deficiency of antioxidants such as vitamins C and E, and beta-carotene, as well as nutrition-related disorders like hypercholesterolemia, hypertension, and diabetes, may also have some role in cognitive impairment. These factors can be present for a long time before cognitive impairment becomes evident, therefore they could be potentially detected and corrected in a timely manner.

Topics: Alzheimer Disease; Antioxidants; Ascorbic Acid; Dementia; Diabetes Mellitus; Diet; Humans; Hyperhomocysteinemia; Hyperlipidemias; Hypertension; Nutrition Disorders; Nutritional Physiological Phenomena; Oxidative Stress; Risk Factors; Vitamin A; Vitamin B Complex; Vitamin E

Research into the oxidation of lipoproteins has yielded many new insights into the pathogenesis of atherosclerosis. However, despite lipoprotein oxidation's biologically plausible role in atherogenesis, several studies have reported inconsistent effects of antioxidants on clinical coronary end points, in sharp contrast with the studies of lipid modification with the 3-hydroxy-3-methylglutaryl coenzyme A inhibitors, or statins. There appears to be little support for the use of antioxidants in coronary prevention. However, the picture remains incomplete. What are the limitations of available antioxidant studies and the agents used? Until the picture can be clarified, lipid modification with strategies proved to reduce the risk for coronary events, such as statins or dietary changes in the style of the Mediterranean diet, should be better implemented in clinical practice.

Topics: Animals; Antioxidants; Ascorbic Acid; beta Carotene; Clinical Trials as Topic; Coronary Artery Disease; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hyperlipidemias; Probucol; Rabbits; Vitamin E

Topics: Ascorbic Acid; Biomarkers; Cholesterol; Cholesterol, HDL; Circadian Rhythm; Clinical Chemistry Tests; Humans; Hyperlipidemias; Reproducibility of Results; Triglycerides

Topics: Ascorbic Acid; Coronary Disease; Fish Oils; Humans; Hyperlipidemias; Lipid Metabolism; Male; Risk Factors; Smoking; Vitamin E

Topics: Adult; Aged; Animals; Arteriosclerosis; Ascorbic Acid; Catecholamines; Diet Therapy; Dietary Fats; Fats, Unsaturated; Female; Humans; Hypercholesterolemia; Hyperlipidemias; Hypertension; Injections, Intra-Arterial; Intermittent Claudication; Male; Mice; Middle Aged; Myocardial Infarction; Nicotine; Obesity; Procaine; Rabbits; Radiography; Smoking; Sympathectomy; Thiamine; Thromboangiitis Obliterans; Tolazoline; Vasodilator Agents

There are concerns that weight-loss (WL) diets based on very low carbohydrate (LC) intake have a negative impact on antioxidant status and biomarkers of cardiovascular and metabolic health. Obese men (n 16) participated in a randomised, cross-over design diet trial, with food provided daily, at approximately 8.3 MJ/d (approximately 70 % of energy maintenance requirements). They were provided with two high-protein diets (30 % of energy), each for a 4-week period, involving a LC (4 % carbohydrate) and a moderate carbohydrate (MC, 35 % carbohydrate) content. Body weight was measured daily, and weekly blood samples were collected. On average, subjects lost 6.75 and 4.32 kg of weight on the LC and MC diets, respectively (P < 0.001, SED 0.350). Although the LC and MC diets were associated with a small reduction in plasma concentrations of retinol, vitamin E (α-tocopherol) and β-cryptoxanthin (P < 0.005), these were still above the values indicative of deficiency. Interestingly, plasma vitamin C concentrations increased on consumption of the LC diet (P < 0.05). Plasma markers of insulin resistance (P < 0.001), lipaemia and inflammation (P < 0.05, TNF-α and IL-10) improved similarly on both diets. There was no change in other cardiovascular markers with WL. The present data suggest that a LC WL diet does not impair plasma indices of cardiometabolic health, at least within 4 weeks, in otherwise healthy obese subjects. In general, improvements in metabolic health associated with WL were similar between the LC and MC diets. Antioxidant supplements may be warranted if LC WL diets are consumed for a prolonged period.

Topics: Adult; Aged; alpha-Tocopherol; Antioxidants; Ascorbic Acid; Biomarkers; Cardiovascular Diseases; Cross-Over Studies; Cryptoxanthins; Diet, Carbohydrate-Restricted; Diet, Reducing; Dietary Carbohydrates; Dietary Proteins; Endothelium, Vascular; Energy Intake; Humans; Hyperlipidemias; Inflammation Mediators; Insulin Resistance; Male; Metabolic Diseases; Middle Aged; Nutritional Requirements; Obesity; Risk Factors; Vitamin A; Weight Loss; Xanthophylls

Data on effects of statins on resting oxidant-antioxidant status are contradictory and no study has been published on the effects of statins on exercise-induced oxidative stress. We carried out a 6-month longitudinal study in 10 dyslipidemic patients receiving 10 mg/day atorvastatin and 13 healthy sedentary subjects. Thiobarbituric acid reactive substances (TBARS) and reduced ascorbic acid (RAA) were measured in plasma at rest and every 5 minutes after submaximal isometric thumb adduction and handgrip sustained until exhaustion. At inclusion, resting TBARS and RAA levels in controls and patients did not differ and exercise increased TBARS and decreased RAA. Atorvastatin reduced resting TBARS and RAA levels in a time-dependent but lipid-independent manner. The main effect was a post-exercise increase in TBARS, without affecting the post-exercise RAA levels. The reduction in oxidative stress occurred earlier in oxidative muscles involved in thumb adduction. In conclusion, atorvastatin lowers resting oxidant-antioxidant activity: exercise-induced oxidative stress occurs mainly in muscles having a high oxidative capacity.

Topics: Anticholesteremic Agents; Antioxidants; Ascorbic Acid; Atorvastatin; Exercise; Female; Heptanoic Acids; Humans; Hyperlipidemias; Isometric Contraction; Longitudinal Studies; Male; Middle Aged; Muscle Fibers, Skeletal; Oxidative Stress; Oxygen Consumption; Pyrroles; Reactive Oxygen Species; Thiobarbituric Acid Reactive Substances

The effect of ascorbate treatment on apheresis-induced oxidative stress in uremic and dyslipidemic patients was evaluated.. We developed a chemiluminescence-emission spectrum and high-performance liquid chromatography analysis to assess the effect of ascorbate supplement on plasma reactive oxygen species (ROS) scavenging activity and oxidized lipid/protein production in hyperlipidemic and uremic patients undergoing apheresis. Apheresis was efficient in reduction of atherogenic lipoproteins, complement, fibrinogen, soluble intercellular adhesion molecule-1, and oxidative parameters including phosphatidylcholine hydroperoxide (PCOOH), malonaldehyde, methylguanidine, and diotyrosine. Apheresis itself, however, activated leukocytes to increase ROS activity and reduced the plasma ROS scavenging activity. Ascorbate administration selectively diminished apheresis-enhanced H2O2 and inflammatory mediators such as tumor necrosis factor alpha (TNF-alpha) and monocyte chemoattractant protein-1. Chronically dyslipidemic and uremic patients undergoing biweekly apheresis plus ascorbate treatment had lower levels of C-reactive protein and PCOOH than did those without ascorbate treatment during a 6-month follow-up study period.. We demonstrate that apheresis with ascorbate treatment provides a therapeutic potential in reducing atherosclerotic risk via inhibition of H2O2-induced oxidative stress in patients with uremia or dyslipidemia.

Topics: Adult; Antioxidants; Ascorbic Acid; Biomarkers; C-Reactive Protein; Combined Modality Therapy; Drug Therapy, Combination; Female; Humans; Hyperlipidemias; Hypolipidemic Agents; Lipid Peroxidation; Luminescent Measurements; Male; Malondialdehyde; Methylguanidine; Middle Aged; Neutrophils; Oxidative Stress; Plasmapheresis; Reactive Oxygen Species; Respiratory Burst; Treatment Outcome; Tyrosine; Uremia; Vitamin E

Statins and fibrates influence endothelial activity and consequently atherogenesis but the mechanisms are not well understood. Twenty Type 2 diabetic patients with dyslipidemia were treated 3 months with simvastatin (20 mg daily) and then 3 months with fenofibrate (200 mg daily) with 2 months of wash-out between the two treatments. Laboratory parameters of oxidative stress, fibrinolysis and endothelial function were evaluated before and at the end of each treatment period. The significant decrease in serum total and LDL-cholesterol concentrations (P<0.0001) caused by simvastatin was associated with an increase in serum N-acetyl-beta-glucosaminidase activity (P<0.001), ascorbic acid (P<0.001), plasminogen activator inhibitor (PAI-1) (P<0.01), vonWillebrand factor (P<0.05), E-selectin (P<0.01) and vascular endothelial growth factor (P<0.05) concentrations and with a decrease in plasma glutathione (P<0.01) levels. Fenofibrate caused a significant decrease in serum triglyceride concentration (P<0.0001) associated with a decrease in plasma malondialdehyde (P<0.001) and an increase in plasma PAI-1 (P<0.05) and P-selectin (P<0.05) concentrations. We conclude that simvastatin and fenofibrate interact, by different mechanisms, with oxidative stress, a key factor in the modification of fibrinolysis and endothelial function in Type 2 diabetes.

Topics: Acetylglucosaminidase; Adult; Aged; alpha-Tocopherol; Ascorbic Acid; Cholesterol; Czech Republic; Diabetes Mellitus, Type 2; Drug Administration Schedule; E-Selectin; Endothelium; Female; Fenofibrate; Fibrinolysis; Glutathione; Humans; Hyperlipidemias; Male; Malondialdehyde; Middle Aged; Oxidative Stress; Plasminogen Activator Inhibitor 1; Simvastatin; Superoxide Dismutase; Time Factors; Triglycerides; Vascular Endothelial Growth Factor A; von Willebrand Factor

To determine effects of oat and antioxidant vitamin (C 500 mg, E 400 IU) ingestion on endothelial function in overweight, dyslipidemic adults.. Randomized, blinded, placebo-controlled, crossover trial Intervention(s): Subjects (16 males > or = age 35; 14 postmenopausal females) were assigned, in random order, to oats (60 g oatmeal), vitamin E (400 IU) plus vitamin C (500 mg), the combination of oats and vitamins, or placebo, and underwent brachial artery reactivity scans (BARS) following a single dose of each treatment, and again following 6 weeks of daily ingestion, with 2-week washout periods. At each test, a provocation high-fat meal (50 g, predominantly saturated) was administered and subjects were scanned pre, and 3 hours post-ingestion.. Mean flow-mediated vasodilation (FMD; measured as percent diameter change before and after treatments) at baseline was 6.35 +/- 3.37. Oats increased FMD non-significantly (p > 0.05) with both single acute dose (from 6.07 +/- 6.25 to 9.22 +/- 8.82) and six weeks of sustained treatment (from 6.01 +/- 10.07 to 8.69 +/- 8.42). The direction of effect was negative for vitamins and the oat/vitamin combination with both acute and sustained treatment. There were no significant differences in FMD change among the treatments in either phase of the study, however when acute and sustained effects were pooled, oat treatment significantly augmented FMD (p < 0.05).. This trial suggests but does not confirm a beneficial influence of oat ingestion on endothelial function in overweight, dyslipidemic adults. Further study of this potential association is warranted.

Topics: Adult; Aged; Antioxidants; Ascorbic Acid; Avena; Blood Flow Velocity; Brachial Artery; Cross-Over Studies; Dietary Fats; Dietary Supplements; Double-Blind Method; Endothelium, Vascular; Female; Humans; Hyperlipidemias; Male; Middle Aged; Obesity; Postprandial Period; Vasodilation; Vitamin E

This study was designed to compare the effects of simvastatin versus a combination of simvastatin with vitamin C or E on serum lipid profile, particularly, high-density lipoprotein (HDL)-cholesterol (C) level, in patients with a low HDL-C level.. Fifty-nine women and 49 men, who had a baseline HDL-C level equal to or lower than 40 mg/dl were randomized to one of the following study treatment groups: Group S (n=39) simvastatin 20 mg/day, Group S+C (n=33) simvastatin 20 mg/day + vitamin C 500 mg/day, and Group S+E (n=36) simvastatin 20 mg/day + vitamin E 400 IU/day. The groups' lipid profiles were obtained at baseline, 3rd and 6th months.. Comparing with baseline values, total-C and low-density cholesterol (LDL-C) values significantly reduced (p<0.001) and HDL-C values significantly increased (Group S--33.9+/-3.9 mg/dl vs. 39.8+/-6.9 mg/dl, Group S+C--34.2+/-3.5 mg/dl vs. 38.1+/-6.1 mg/dl, Group S+E--33.1+/-3.6 mg/dl vs. 34.8+/-5.9 mg/dl, p<0.001) on therapy within the groups; however, there were no significant differences among the groups with regards to these parameters. The HDL-C levels increased from baseline by 14.0%, 11.7% and 10.2% in Group S, S+C, and S+E, respectively (p>0.05).. A combination of simvastatin with antioxidant vitamins does not offer any beneficial effect over simvastatin alone. Particularly vitamin E seems to blunt the simvastatin induced HDL-C increase.

Topics: Administration, Oral; Antioxidants; Ascorbic Acid; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Drug Administration Schedule; Female; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hyperlipidemias; Lipids; Male; Simvastatin; Treatment Outcome; Vitamin E

Hypertension is considered resistant if blood pressure cannot be reduced to <140/90 mmHg with an appropriate triple-drug regimen, including an oral diuretic, with all agents administered at maximal dosages. This definition has evolved with the development of new therapies and evidence-based data supporting treatment to lower BP goals.. To assess whether vitamin C and atorvastatin improve endothelial function and blood pressure control in subjects with resistant arterial hypertension and dyslipidemia.. Forty-eight hyperlipidemic subjects with RH (office systolic BP >140 mmHg and/or office diastolic BP >90 mmHg notwithstanding antihypertensive treatment with three medications in maximal doses) were randomized into three groups to receive additional medication for 8 weeks. Group VTC (n = 17)--mean 24 hour SBP 150.6 +/- 5.2 mmHg, DBP 86.1 +/- 3.3 mmHg, low density lipoprotein 158.1 +/- 24.5 mg/dl--received vitamin C 500 mg per day; Group ATR (n = 15)--mean 24 hour SBP 153.1 +/- 4.8 mmHg, DBP 87.1 +/- 6.7 mmHg, LDL 162.6 +/- 13.6 mg/dl--received atorvastatin 20 mg/day; and Group PLA (n = 16)--mean 24 hour SBP 151.1 +/- 7.4 mmHg, DBP 84.8 +/- 5.9 mmHg, LDL 156.7 +/- 26.1 mg/dl--received a placebo. High resolution ultrasound was used to calculate brachial artery flow-mediated dilation, and 24 hour ambulatory BP monitoring was performed at study entry and after 8 weeks.. In the ATR group there were significant reductions of SBP (deltaSBP1-2: 13.7 +/- 5.6 mmHg, P 0.001), DBP (deltaDBP1-2: 7.8 +/- 5.7 mmHg, P 0.01), LDL (deltaLDL1-2: 67.7 +/- 28.3 mg/dl, P < 0.001) and improvement of brachial artery FMD (deltaFMD2-1: 4.2 +/- 2.6%). No significant changes in BP, LDL and FMD were observed in the other two groups.. In subjects with RH and dyslipidemia, atorvastatin 20 mg/day compared to vitamin C 500 mg/day may help to achieve better BP control and improve endothelial function in a finite period. A larger trial is needed to assess the drug's efficacy in this population for longer periods.

Topics: Anticholesteremic Agents; Antihypertensive Agents; Ascorbic Acid; Atorvastatin; Blood Pressure; Brachial Artery; Cross-Sectional Studies; Endothelium, Vascular; Female; Heptanoic Acids; Humans; Hyperlipidemias; Hypertension; Male; Middle Aged; Pyrroles

This randomized, placebo-controlled, double-blind, crossover study on 25 free-living hyperlipidaemic volunteers aspired to prove the hypothesis that supplementation for 8 weeks with a FoodState Vitamin C complex (500 mg vitamin C, 160 mg bioflavonoids, 600 mg magnesium and 900 mg vitamin B complex) may improve haemostatic factors and fibrin network structures. Of the haemostatic factors measured, only median plasmin-antiplasmin complex (PAP) and thrombin-antithrombin complex (TAT) concentrations were both significantly decreased with FoodState Vitamin C complex compared with placebo [PAP, -4.05% (-23.39, -0.23) versus 1.81% (-8.95, 8.09); TAT, -5.81% (-18.47, 0.39) versus 0.12% (-8.03, 13.5)]. As for fibrin network structures, only compaction was significantly increased from baseline to end [49.95% (47.55, 53.70) to 51.85% (48.55, 56.65)] by FoodState Vitamin C complex supplementation. No significant changes were found in plasma fibrinogen, plasminogen activator inhibitor 1 activity, tissue plasminogen activator antigen, D-dimer, serum lipids or lipoprotein (a) concentrations. In conclusion, the decreases in TAT and PAP are possibly an indication that the FoodState Vitamin C complex decreased the initiation of haemostasis, which in turn led to a compensatory reduction in fibrinolysis. FoodState Vitamin C complex may therefore be protective of cardiovascular disease by causing a new reduced steady state of haemostatic balance and less rigid clots (increased compaction).

Topics: Adult; alpha-2-Antiplasmin; Antithrombin III; Ascorbic Acid; Biomarkers; Cross-Over Studies; Double-Blind Method; Female; Fibrin; Fibrinolysin; Hemostasis; Humans; Hyperlipidemias; Lipids; Male; Middle Aged; Peptide Hydrolases

Insulin therapy may influence cardiovascular disease (CVD) and lipid metabolism in type 2 diabetes (T2D). Exaggerated postprandial lipaemia (PPL) is a feature of diabetic dyslipidaemia affecting CVD via enhanced oxidative stress (OS) and endothelial dysfunction. We assessed endothelial function and OS during PPL following insulin and vitamin C. Twenty (17 M) T2D patients were studied (mean Hba1c 8.4%) at baseline, following 6 weeks of insulin lispro (0.2 Iu kg-1) and vitamin C 1-g daily. Eight-h lipid and glucose profiles were measured following a fatty meal. Endothelial function (flow-mediated vasodilatation: FMD) and OS were measured at fasting, 4 h and 8 h.. Glucose, body mass index, and total and LDL cholesterol remained unchanged. FMD improved. Placebo group: fasting, 1.1 +/- 1.2 to 4.2 +/- 1.1% (P < 0.001); 4-h, 0.3 +/- 1.2 to 3.1 +/- 0.9% (P < 0.01); 8-h, 0.7 +/- 1.1 to 3.76 +/- 1.1% (P < 0.001). Vitamin C group: fasting, 0.9 +/- 1.1 to 6.1 +/- 1.3% (P < 0.001); 4-h, 0.7 +/- 1.5 to 4.9 +/- 2.1% (P < 0.001); 8-h, 0.8 +/- 0.9 to 5.8 +/- 0.6% (P < 0.01). Post-prandial lipaemia was attenuated: TG area-under-curve (mmol L-1 8 h-1), 52.6 +/- 11 to 39.1 +/- 12.5 (placebo group), P < 0.02; and 56.9 +/- 8 to 40.1 +/- 10.3 (vitamin C group), P < 0.02. Oxidative stress was reduced, with greater changes in the vitamin C group.. Insulin may thus exert vascular benefits in T2D, by modifying fasting and postprandial lipid metabolism resulting in reduced OS and improved EF. Vitamin C therapy may augment the vascular benefits of insulin in T2D through additional effects on OS and EF.

Topics: Adult; Ascorbic Acid; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Endothelium, Vascular; Female; Humans; Hyperlipidemias; Hypoglycemic Agents; Insulin; Insulin Lispro; Male; Middle Aged; Oxidative Stress; Postprandial Period

Control of hyperlipidemia is vital in patients with cardiovascular disease (CVD). Omega-3 fatty acids (n-3FAs) have desirable effects on serum triglyceride (TG) levels, thrombosis, and arrhythmia, but lead to increases in serum low-density lipoprotein (LDL) and apo-B as well.. To determine and compare the effects of administration of n-3FAs, vitamin C (VitC) and n-3FAs + VitC on the serum levels of LDL, apoB, other serum lipids, and malondialdehyde (MDA). The present study was performed in Tehran University of Medical Sciences from 2000 to 2001.. In a double-blind, placebo trial of parallel design, 68 hyperlipidemic patients [total cholesterol (TC) and TG greater than 200 mg/dL] were randomly assigned to receive daily 500 mg VitC, 1 g n-3FAs, 500 mg VitC + 1 g n-3FAs, or placebo (control) for 10 weeks. Fasting blood samples were collected at the beginning and at the end of the period. TG, TC, LDL-cholesterol-C (LDL-C), and high-density lipoprotein-cholesterol (HDL-C) were measured enzymatically, VitC and MDA colorimetrically, and apo-B and apo-A-I immunoturbidometrically. The pattern of food consumption, socio-economic, and anthropometric indices were determined; there was no significant change in these indices during the study.. There was a significant difference in the blood VitC level at the end of the study in comparison to the initial value in the VitC (p = 0.001) and VitC + n-3FAs (p = 0.027) groups. Similarly, the serum TG level at the end of study was significantly different from the initial value in the n-3FAs group (p = 0.002) and also from the final value in the control group (p = 0.013). In the VitC group, there was a significant decrease in TC (p = 0.004), apo-B (p = 0.005), and MDA (p = 0.015) at the end of study as compared to the respective initial values. There was also a significant increase in blood VitC compared to the control value (p = 0.018) and a significant decrease in MDA compared to the n-3FAs group (p = 0.034). At the end of study, in the n-3FAs group, there was a significant (p = 0.04) and a marginally significant decrease (p = 0.05), respectively, in TG/HDL and apo-B levels as compared to the initial values, and the TG/HDL ratio showed a significant decrease as compared to the control group (p = 0.047).. Simultaneous administration of n-3FAs and VitC had no beneficial effects on the lipid profile of hyperlipidemic patients, but 1 g purified n-3FAs daily for 10 weeks is a beneficial supplement for decreasing TG without any increase in LDL-C, apo-B or MDA. Administration of 500 mg VitC for more than 10 weeks might decrease significantly TC and apo-B in hyperlipidemic patients.

Topics: Adult; Aged; Apolipoprotein A-I; Apolipoproteins B; Ascorbic Acid; Double-Blind Method; Drug Synergism; Fatty Acids, Omega-3; Female; Humans; Hyperlipidemias; Lipoproteins; Male; Malondialdehyde; Middle Aged; Triglycerides

Hyperlipidemia is associated with endothelial dysfunction, an early event in atherosclerosis and predictor of risk for future coronary artery disease. Epidemiological studies suggest that increased dietary intake of antioxidants reduces the risk of coronary artery disease. The purpose of this study was to determine whether antioxidant vitamin therapy improves endothelial function and affects surrogate biomarkers for oxidative stress and inflammation in hyperlipidemic children.. In a randomized, double-blind, placebo-controlled trial, the effects of antioxidant vitamins C (500 mg/d) and E (400 IU/d) for 6 weeks and the National Cholesterol Education Program Step II (NCEP-II) diet for 6 months on endothelium-dependent flow-mediated dilation (FMD) of the brachial artery were examined in 15 children with familial hypercholesterolemia (FH) or the phenotype of familial combined hyperlipidemia (FCH). Antioxidant vitamin therapy improved FMD of the brachial artery compared with baseline (P<0.001) without an effect on biomarkers for oxidative stress (autoantibodies to epitopes of oxidized LDL, F2-isoprostanes, 8-hydroxy-2'-deoxyguanosine), inflammation (C-reactive protein), or levels of asymmetric dimethylarginine, an endogenous inhibitor of nitric oxide.. Antioxidant therapy with vitamins C and E restores endothelial function in hyperlipidemic children. Early detection and treatment of endothelial dysfunction in high-risk children may retard the progression of atherosclerosis.

Topics: Adolescent; Adult; Antioxidants; Ascorbic Acid; Brachial Artery; Child; Cross-Over Studies; Double-Blind Method; Endothelium, Vascular; Female; Humans; Hyperlipidemias; Male; Vasodilation; Vitamin E

Fifty diabetic patients took part in a four-month, double-blind crossover study comparing 500 mg of vitamin C daily with placebo. No significant difference was observed between vitamin C and placebo therapy in fasting whole blood glucose, serum cholesterol, triglycerides, and glycosylated haemoglobin levels.

Topics: Ascorbic Acid; Clinical Trials as Topic; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Double-Blind Method; Humans; Hyperlipidemias; Time Factors

An excessive cholesterol level can lead to cardiovascular diseases, such as stroke, hypertension, and myocardial infarction. A non-invasive, painless method of determining the cholesterol level in blood would improve the user's convenience. To provide rapid and accurate determination of cholesterol, we have developed a simple, disposable, enzyme-based electrochemical biosensor that can detect salivary cholesterol. It is possible to detect low concentrations of cholesterol in saliva using the optimized vertical structure of the platinum nano-cluster (Pt-NC) and the immobilization of a proper volume of an enzyme. The biosensor exhibited a linear range from 2 to 486 μM, the limit of detection was about 2 μM, and the sensitivity of the sensor was calculated to be 132 μA mM-1 cm-2. It also showed good specificity for ascorbic acid, uric acid, dopamine, glucose, and lactate. In a test with an actual sample, the performance of the biosensor was confirmed by measuring total cholesterol in the saliva of a patient with hyperlipidemia. The cholesterol levels measured in the saliva of three patients with hyperlipidemia were 520, 460, and 290 μM. Therefore, the Pt-NC based enzyme sensor is a promising candidate for the detection of cholesterol in human saliva.

Topics: Ascorbic Acid; Biosensing Techniques; Cholesterol; Cholesterol Oxidase; Electrochemical Techniques; Enzymes, Immobilized; Glucose; Humans; Hyperlipidemias; Limit of Detection; Nanostructures; Platinum; Saliva; Uric Acid

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/ApoER61. 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/ApoER61. 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.

Topics: Animals; Antioxidants; Apolipoprotein B-48; Ascorbic Acid; Cardiotonic Agents; Coronary Artery Disease; Cytokines; Diet, Atherogenic; Dietary Supplements; Enzyme-Linked Immunosorbent Assay; Female; Hyperlipidemias; Immunoblotting; Lipid Metabolism; Lipoproteins, HDL; Male; Mice, Inbred C57BL; Myocardial Ischemia; Phospholipid Transfer Proteins; Reference Values; Reproducibility of Results; Scavenger Receptors, Class B; Treatment Outcome; Vitamin E

Chronic ethanol exposure causes hyperlipidemia. The present study was designed to investigate the impact of ascorbic acid supplementation on ethanol induced hyperlipidemia in testis and to compare it with that of abstinence from taking alcohol.. Thirty-six male guinea pigs were divided into two groups and were maintained for 90 days as follows (1) control (C) (2) ethanol treated group (E) (4 g/kg body wt/day). Ethanol was administered for 90 days and on 90th day, alanine amino transaminase (ALT), aspartate amino transaminase (AST) and γ-glutamyltransferase (GGT) in serum was assayed. The animals in the ethanol group were further divided into an ascorbic acid supplemented group (25 mg/100 g body wt/day) (E+AA) and an ethanol abstention group (EAG) and those in the control group were divided into a control group and a control+ascorbic acid group (C+AA).. There was significant increase in levels of testicular cholesterol, free fatty acid, phospholipids and triglycerides in the ethanol group. There was also a significant increase in the activity of HMG CoA reductase and decrease in activity of testicular glucose-6-phosphate dehydrogenase (G6PDH) and malic enzyme in ethanol-ingested animals that further led to decreased levels of serum testosterone. Alcohol administration also enhanced the activity of testicular alcohol dehydrogenase (ADH). Ascorbic acid supplementation and abstention altered all these parameters induced by chronic alcohol administration. Histological studies were also in line with the above results.. Ascorbic acid was able to reinstate the cholesterol homeostasis in testis which could have further restored the testicular steroidogenesis. The present study demonstrated that ascorbic acid is effective in reducing the hyperlipidemia induced by chronic alcohol administration and produced a better recovery than abstention.

Topics: Alanine Transaminase; Alcohol Abstinence; Alcohol Dehydrogenase; Animals; Ascorbic Acid; Aspartate Aminotransferases; Dietary Supplements; Ethanol; gamma-Glutamyltransferase; Glucosephosphate Dehydrogenase; Guinea Pigs; Hydroxymethylglutaryl CoA Reductases; Hyperlipidemias; Malate Dehydrogenase; Male; Testis; Testosterone

Thiazole derivatives are attractive candidates for drug development because they can be efficiently synthesized and are active against a number of diseases and conditions, including diabetes. In our present study, we investigated the anti-inflammatory and antioxidant properties of N-adamantyl-4-methylthiazol-2-amine (KHG26693), a new thiazole derivative, in a streptozotocin (STZ)-induced model of diabetes mellitus. STZ-induced diabetic rats were intraperitoneally administered KHG26693 (3mg/kg-body weight/day) for 4 weeks. KHG26693 administration significantly decreased blood glucose, triglycerides, and cholesterol and increased insulin. KHG26693 also suppressed several inflammatory responses in STZ-induced diabetic rats, as evidenced by decreased levels of serum tumor necrosis factor-α, interleukin-1β, and nitric oxide. Additionally, KHG26693 significantly modulated hepatic lipid peroxidation, catalase and superoxide dismutase activity, and the nonenzymatic antioxidant status (e.g., vitamins C and E), and reduced the glutathione content. These anti-inflammatory/antioxidative actions occurred as a result of the downregulation of inducible nitric oxide synthase and nuclear factor-kappa B. Taken together, our results suggest that KHG26693 successfully reduces the production of oxidative stress in STZ-induced diabetic rats by regulating the oxidation-reduction system, specifically increasing antioxidant capacity. Furthermore, KHG26693 treatment significantly reverted the key enzymes of glucose metabolism, such as glucokinase, glucose-6-phosphatase, glycogen synthase, glycogen phosphorylase, and fructose-1,6-bisphosphatase, to near-normal levels in liver tissues. These results indicate that KHG26693 normalizes disturbed glucose metabolism by enhancing glucose utilization and decreasing liver glucose production via insulin release, suggesting the possibility of future diabetes treatments.

Topics: Adamantane; Animals; Anti-Inflammatory Agents; Antioxidants; Ascorbic Acid; Blood Glucose; Catalase; Diabetes Mellitus, Experimental; Glutathione; Hyperglycemia; Hyperlipidemias; Hypoglycemic Agents; Hypolipidemic Agents; Insulin; Interleukin-1beta; Lipid Metabolism; Lipid Peroxidation; Liver; Male; Malondialdehyde; NF-kappa B; Nitric Oxide; Oxidative Stress; Rats, Sprague-Dawley; Superoxide Dismutase; Thiazoles; Tumor Necrosis Factor-alpha; Vitamin E

Chronic ethanol (EtOH) consumption is associated with oxidative tissue damage, decrease in antioxidant enzyme activities, and increase in hepatic and plasma lipids. This study investigates the effect of modified probiotic Escherichia coli Nissle 1917 (EcN) secreting pyrroloquinoline quinone (PQQ) against EtOH-induced metabolic disorder in rats.. Male Charles Foster rats were gavaged with EtOH (5 g/kg body weight [acute study] and 3 g/kg body weight per day for 10 weeks [chronic study]).. Pretreatment of PQQ, vitamin C, and PQQ-secreting EcN prevented acute EtOH-induced oxidative damage in rats reflected by reduced lipid peroxidation in blood and liver and increased hepatic reduced glutathione. However, PQQ given externally was found to be most effective against acute EtOH toxicity. In the chronic study, rats treated with PQQ-secreting EcN showed remarkable reduction in oxidative tissue damage (liver, colon, blood, and kidney) with significant increase in antioxidant enzyme activities as compared to only EtOH-treated rats. Additionally, these rats had significantly lowered hepatic and plasma lipid levels with concomitant reduction in mRNA expression of fatty acid synthase (0.5-fold) and increase in mRNA expression of acyl coenzyme A oxidase (2.4-fold) in hepatic tissue. Antioxidant and hyperlipidemic effects of PQQ-secreting EcN are correlated with increased colonic short chain fatty acids (SCFAs; i.e., acetate, propionate, and butyrate) levels, and PQQ concentration in fecal samples (2-fold) and liver (4-fold). Extracted PQQ and vitamin C were given once a week, but they did not exhibit any ameliorative effect against chronic EtOH toxicity.. Accumulated PQQ in tissues prevents hepatic and systemic oxidative damage. PQQ along with SCFAs reduced hyperlipidemia, which can be correlated with changes in mRNA expression of hepatic lipid metabolizing genes. Our study suggests that endogenous generation of PQQ by EcN could be an effective strategy in preventing alcoholic liver disease.

Topics: Animals; Antioxidants; Ascorbic Acid; Drug Administration Schedule; Escherichia coli; Ethanol; Hyperlipidemias; Liver; Male; Oxidative Stress; PQQ Cofactor; Probiotics; Rats

The synthesis of a series of benzocoumarin keto-enamine schiff bases is reported. The novel compounds were evaluated for their antihyperlipidemic activity in the hyperlipidemic hamster model. The compound 11 at a dose of 10 mg/kg body weight significantly lowered the plasma triglyceride levels (TG) by 70%, total cholesterol (TC) by 47%, accompanied by an increase in HDL-C/TC ratio by 80% in hyperlipidemic hamsters to a greater degree than the reference drugs atorvastatin and lovastatin.

Topics: Animals; Benzene; Cholesterol; Cholesterol, HDL; Coumarins; Cricetinae; Hyperlipidemias; Hypolipidemic Agents; Schiff Bases; Triglycerides

The roots of Glycyrrhiza glabra, Withania somnifera, Asparagus racemosus, and Chlorophytum borivilianum and seeds of Sesamum indicum are ayurvedic medicinal plants used in India to treat several ailments. Our previous studies indicated that these plants possess hypolipidemic and antioxidant potential. The present study was aimed at investigating the composite effects of these plants on hypercholesterolemic rats. Three different combinations (5 gm%, given for four weeks) used in this study effectively reduced plasma and hepatic lipid profiles and increased fecal excretion of cholesterol, neutral sterol, and bile acid along with increasing the hepatic HMG-CoA reductase activity and bile acid content in hypercholesterolemic rats. Further, all three combinations also improved the hepatic antioxidant status (catalase, SOD, and ascorbic acid levels) and plasma total antioxidant capacity with reduced hepatic lipid peroxidation. Overall, combination I had the maximum effect on hypercholesterolemic rats followed by combinations II and III due to varying concentrations of the different classes of phytocomponents.

Topics: Animals; Ascorbic Acid; Asparagus Plant; Bile Acids and Salts; Catalase; Chlorophyta; Feces; Glycyrrhiza; Hydroxymethylglutaryl CoA Reductases; Hyperlipidemias; Lipid Peroxidation; Lipids; Liver; Male; Plant Extracts; Rats; Sesamum; Superoxide Dismutase; Withania

Wheat grass is used as a general health tonic and is reported to be effective against several medical disorders, although detailed literature is not available. Besides drug therapy, a number of medicinal plants are effective in treating hyperlipidemia. This study examined the effects of wheat grass on high-fat diet-induced hyperlipidemia in rabbits. Thirty rabbits were divided into 3 groups of 10 rabbits each, group I receiving a control diet, group II a high-fat diet and group III a high-fat diet together with wheat grass over a period of 10 weeks. Fasting serum samples from the animals were analyzed for total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), malondialdehyde (MDA), reduced glutathione (GSH) and vitamin C, and the results were compared. The high-fat diet resulted in hyperlipidemia and an increase in oxidative stress, indicated by a significant rise in MDA levels, whereas antioxidant levels of GSH and vitamin C were significantly reduced. Wheat grass supplementation with a high-fat diet resulted in improved lipid levels (decreased total cholesterol and increased HDL-C) together with significantly reduced MDA levels and increased GSH and vitamin C levels. These results indicate the beneficial role of wheat grass in ameliorating hyperlipidemia and the associated oxidative stress.

Topics: Animals; Antioxidants; Ascorbic Acid; Dietary Fats; Female; Glutathione; Hyperlipidemias; Male; Malondialdehyde; Oxidative Stress; Phytotherapy; Plant Preparations; Rabbits; Triticum

Nutritional values of buckwheat reach maximum on day 8 sprouting by solid-phase cultivation (BSSC). The precious nutrients surveyed included linolenic acid, total polyphenolics, rutin, quercetin, l-ascorbic acid and gamma-aminobutyric acid. To investigate whether a change of cultivation method could improve the nutritional status, we performed aquaculture. By performing chemical, biochemical and animal experiments, we found that maximization of nutrient levels in aquacultured buckwheat sprouts (BSAQ) occurred 2 days earlier than those from BSSC. Simultaneously, their bioactivities were much enhanced, being superior to BSSC regarding antioxidative, free radical scavenging (FRS), anti-low-density lipoprotein lipoperoxidative capabilities and hypolipidemic bioactivity with respect to serum total cholesterol and triglyceride levels in Syrian hamsters. In addition, serum low-density lipoprotein-cholesterol (LDL-C) and high-density lipoprotein-cholesterol (HDL-C) levels and the ratios LDL-C/HDL-C and total cholesterol/HDL-C were all more efficiently suppressed by BSAQ diets. In conclusion, aquaculture is more efficient than the solid-phase cultivation with regard to acceleration and maximization of precious nutrient levels in buckwheat sprouts.

Topics: Agriculture; alpha-Linolenic Acid; Animals; Antioxidants; Ascorbic Acid; Cricetinae; Dietary Fats; Fagopyrum; gamma-Aminobutyric Acid; Germination; Hyperlipidemias; Hypolipidemic Agents; Lipids; Male; Nutritive Value; Phytotherapy; Plant Preparations; Plant Shoots; Polyphenols; Quercetin; Rutin; Seeds

Cardiovascular disease (CVD) is the most important adult health problem in the world. Epidemiological studies and laboratory experiments have shown that fruit and vegetable consumption has protective effects against CVD. The purpose of the study was to investigate the effects of consumption of two kiwifruit per day on the lipid profile, antioxidants and markers of lipid peroxidation in hyperlipidemic adult men and women in Taiwan. Forty-three subjects who had hyperlipidemia, including 13 males and 30 females, participated in this study. They were asked to consume two kiwifruit per day for 8 weeks. Anthropometric measurements were made. Before the intervention and at 4 and 8 weeks of the intervention, fasting blood samples were analyzed for total cholesterol, triacylglycerol, low-density lipoprotein (LDL) cholesterol, and high-density lipoprotein cholesterol (HDL-C). Additionally vitamin E and vitamin C, the malondialdehyde + 4-hydroxy-2(E)-nonenal concentration, and the lag time of LDL oxidation were determined. No significant differences from baseline to 8 weeks of the intervention were detected for triacylglycerol, total cholesterol, or LDL cholesterol. However, after 8 weeks of consumption of kiwifruit, the HDL-C concentration was significantly increased and the LDL cholesterol/HDL-C ratio and total cholesterol/HDL-C ratio were significantly decreased. Vitamin C and vitamin E also increased significantly. In addition, the lag time of LDL oxidation and malondialdehyde + 4-hydroxy-2(E)-nonenal had significantly changed at 4 and 8 weeks during the kiwifruit intervention. Regular consumption of kiwifruit might exert beneficial effects on the antioxidative status and the risk factors for CVD in hyperlipidemic subjects.

Topics: Actinidia; Adult; Aged; Aldehydes; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Cholesterol; Female; Fruit; Humans; Hyperlipidemias; Lipid Peroxidation; Lipids; Lipoproteins; Lipoproteins, LDL; Male; Middle Aged; Oxidation-Reduction; Risk Factors; Time Factors; Vitamin E; Young Adult

Nutrient levels in buckwheats that were maximized in day 8 sprouts (D8SP) included total phenolics, quercetin, and l-ascorbic acid, whereas those of oxalic, malic, tartaric, and citric acids, rutin, and gamma-aminobutyric acid (GABA) were found to reach maximum levels on day 10. Ethanolic extract of D8SP (2.5 mg/mL) revealed potent free-radical scavenging (FRS) and antioxidative (ANO) capabilities. However, its Fe2+-chelating capability was only moderate. To further study the hypolipidemic activity of D8SP, 36 Syrian hamsters were grouped into six groups and fed for 28 days, respectively, with (i) control meal, (ii) high fat plus high cholesterol meal, (iii) high fat plus high cholesterol plus 2.5% of buckwheat seeds, (iv) high fat plus high cholesterol plus 25% of buckwheat seeds, (v) high fat plus high cholesterol plus 2.5% of D8SP, and (vi) high fat plus high cholesterol plus 25% of D8SP. High seed meal prominently enhanced body weight gain, whereas high sprout meal exhibited the highest feed efficiency. Ratios of liver/body weight (L/B) were significantly lowered by all BS meals. Although low seed meal reduced serum total cholesterol (TC) levels (p<0.05), its effect was still inferior to the high seed and sprout meals (p<0.01). In contrast, serum triglyceride (TG) levels were lowered only by the high seed and sprout meals (p<0.05). Alternatively, levels of serum low-density lipoprotein cholesterol (LDL-C) were significantly suppressed by all buckwheat meals (p<0.01). Serum high-density lipoprotein cholesterol (HDL-C) levels were increased, however, insignificantly. Nutraceutically more meaningful is that both LDL-C/HDL-C and TC/HDL-C ratios were significantly lowered (p<0.01). Apparently, hepatic TC levels were significantly reduced, whereas hepatic TG levels were totally unaffected. Conclusively, sprouting triggers a variety of nutritional changes in buckwheats. Day 8 sprouts, consisting of high polyphenolic and moderate quercetin contents, are nutraceutically maximized when hypocholesterolemic, hypotriglyceridemic, and antioxidative activities are concerned.

Topics: Aminobutyrates; Animals; Ascorbic Acid; Cholesterol; Cricetinae; Fagopyrum; Fatty Acids; Flavonoids; Food Analysis; Free Radical Scavengers; Germination; Hyperlipidemias; Hypolipidemic Agents; Phenols; Phytotherapy; Plant Extracts; Polyphenols; Quercetin; Random Allocation; Rutin; Seeds; Triglycerides; Weight Gain

1. The present study examined the efficacy of Chlorophytum borivilianum root (powder) in modulating the hyperlipaemic/hypercholesteraemic conditions in male albino rats. 2. Administration of C. borivilianum (0.75 and 1.5 g root powder/rat per day for 4 weeks) to hypercholesteraemic rats significantly increased high-density lipoprotein-cholesterol levels and decreased plasma and hepatic lipid profiles. 3. In addition, there were significant increases in faecal cholesterol, neutral sterol and bile acid excretion with elevated hepatic 3-hydroxy-3-methylglutaryl coenzyme A reductase activity and bile acid production. 4. Furthermore, the hypercholesteraemic rats treated with both doses of C. borivilianum also exhibited increases in superoxide dismutase and ascorbic acid levels. 5. Normocholesteraemic animals treated with both doses of C. borivilianum root powder did not show any significant variation in either lipid or anti-oxidant profiles, except for an increase in the hepatic ascorbic acid concentration compared with their untreated counterparts. 6. The hypolipaemic/hypocholesteraemic effect of C. borivilianum root powder appears to be mediated by an increase in cholesterol turnover via increased faecal cholesterol excretion and, second, through an endogenous cholesterol conversion into bile acid. 7. Administration of C. borivilianum root powder also increased the activities of anti-oxidant enzymes and vitamin C levels, which may have enhanced the anti-oxidant capacity of the liver.

Topics: Animals; Antioxidants; Ascorbic Acid; Bile Acids and Salts; Catalase; Cholesterol; Diet; Feces; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypercholesterolemia; Hyperlipidemias; Liliaceae; Lipid Metabolism; Lipids; Liver; Male; Plant Extracts; Plant Roots; Rats; Sterols; Superoxide Dismutase; Triglycerides

The hyperglycemia and hyperoxidation that characterize diabetes lead to reduced vitamin C (L-ascorbic acid, AA) levels in diabetic humans and animals. We examined the possibility that diabetes-induced low plasma AA levels impair AA distribution to various tissues and that these changes are closely related to the development of diabetic complications. AA levels were markedly decreased in the plasma and increased in the adrenals of mice with streptozotocin (STZ)-induced diabetes. Consistently with these results, in [1-(14)C]AA accumulation assays, the efficiency of [1-(14)C]AA accumulation was significantly higher in the adrenals (which had the greatest ability to accumulate [1-(14)C]AA) of diabetic mice than in those of controls. Expression of sodium-dependent vitamin C transporter (SVCT)-2, a transporter of AA, was upregulated in diabetic adrenals. Furthermore, increased AA incorporation into the diabetic adrenals by SVCT-2 led to increased plasma norepinephrine, triglyceride and free fatty acid levels in mice with STZ-induced diabetes. Therefore, oversupplementation with AA could be deleterious in diabetic patients, because overexpression of adrenal SVCT-2 in diabetes could lead to excessive AA uptake, thus enhancing norepinephrine production and exacerbating some diabetic complications. Interestingly, however, treatment with AA dose-dependently abolished the increased expression of adrenal SVCT-2 and normalized the abovementioned plasma parameters in diabetic mice. These results suggest SVCT-2-mediated increases in AA uptake by the adrenals followed by excessive production of plasma norepinephrine may play a pivotal role in the development of diabetic complications.

Topics: Adrenal Glands; Animals; Ascorbic Acid; Diabetes Mellitus, Experimental; Dose-Response Relationship, Drug; Gene Expression Regulation; Hyperlipidemias; Kidney; Mice; Mice, Inbred ICR; Norepinephrine; Organic Anion Transporters, Sodium-Dependent; RNA, Messenger; Sodium-Coupled Vitamin C Transporters; Streptozocin; Symporters; Up-Regulation

A high-cholesterol diet stimulates alveolar bone resorption, which may be induced via tissue oxidative damage. Vitamin C reduces tissue oxidative damage by neutralizing free radicals and scavenging hydroxyl radicals, and its antioxidant effect may offer the clinical benefit of preventing alveolar bone resorption in cases of hyperlipidemia. We examined whether vitamin C could suppress alveolar bone resorption in rats fed a high-cholesterol diet.. In this 12-week study, rats were divided into four groups: a control group (fed a regular diet) and three experimental groups (fed a high-cholesterol diet supplemented with 0, 1, or 2 g/l vitamin C). Vitamin C was provided by adding it to the drinking water. The bone mineral density of the alveolar bone was analyzed by microcomputerized tomography. As an index of tissue oxidative damage, the 8-hydroxydeoxyguanosine level in the periodontal tissue was determined using a competitive enzyme-linked immunosorbent assay.. Hyperlipidemia, induced by a high-cholesterol diet, decreased rat alveolar bone density and increased the number of tartrate-resistant acid phosphatase-positive osteoclasts. The expression of 8-hydroxydeoxyguanosine was upregulated in the periodontal tissues. Intake of vitamin C reduced the effect of a high-cholesterol diet on alveolar bone density and osteoclast differentiation and decreased periodontal 8-hydroxydeoxyguanosine expression.. In the rat model, vitamin C suppressed alveolar bone resorption, induced by high dietary cholesterol, by decreasing the oxidative damage of periodontal tissue.

Topics: Alveolar Process; Animals; Antioxidants; Ascorbic Acid; Bone Density; Bone Resorption; Cholesterol; Diet; Hyperlipidemias; Male; Osteoclasts; Rats; Rats, Wistar

Alcoholics usually suffer from malnutrition and are especially deficient in micronutrients like vitamin C, selenium and Zn. In the present study, combined effects of selenium and ascorbic acid on alcohol-induced hyperlipidemia were studied in guinea pigs. Four groups of male guinea pigs were maintained for 45 days as follows: control (1 mg ascorbate (AA)/100 g body mass/day), ethanol (900 mg ethanol/100 g body mass + 1 mg AA/100 g body mass/day), selenium+ascorbic acid [(25 mg AA + 0.05 mg Se)/100 g body mass/day], ethanol+selenium+ascorbic acid [(25 mg AA + 0.05 mg Se + 900 mg ethanol)/100 g body mass/day]. Co-administration of selenium and ascorbic acid along with alcohol reduced the concentration of all lipids, as also evidenced from the decreased activities of hydroxymethylglutaryl-CoA reductase and enhanced activities of plasma lecithin cholesterol acyl transferase and lipoprotein lipase. Concentrations of bile acids were increased. We conclude that the supplementation of Se and ascorbic acid reduced alcohol induced hyperlipidemia, by decreased synthesis and increased catabolism.

Topics: Animals; Ascorbic Acid; Drug Combinations; Ethanol; Guinea Pigs; Hyperlipidemias; Male; Selenium

To compare plasma concentration of alpha-tocopherol and ascorbic acid in healthy seniors (age over 65 years), senior patients with either diabetes mellitus, acute myocardial infarction or dyslipidemia and recommended values of these vitamins.. Studied groups included 30 patients with diabetes mellitus (DM); 30 patients 1 - 2 weeks after acute myocardial infarction (AMI); 11 patients with lipid metabolism disorder (LD, total cholesterol > 6.2 mM); and control group of 27 healthy persons.. Concentration of alpha-tocopherol in DM group was 14.6 +/- 5.3 microM, in AMI group 13.7 +/- 5.6 microM, in LD group 15.9 +/- 5.6 microM and in control group 12.9 +/- 4.1 microM. No statistically significant differences were found. However, comparison of determined values with levels recommended for prevention revealed remarkable low plasma concentration of alpha-tocopherol in the Czech population. Plasma concentration of ascorbic acid in DM group was 47.07 +/- 22.80 microM, in AMI group 33.15 +/- 12.81 microM, in LD group 45.59 +/- 23.02 microM and in control group 43.28 +/- 26.57 microM. No statistically significant differences were found between the controls and individual groups of patients. Plasma concentrations of vitamin C reached the recommended value in all cases except the AMI group, where it was significantly lower.. Seniors in the Czech population were proved to be significantly short of alpha-tocopherol, minor shortage of vitamin C was found only in group of patients with myocardial infarction.

Topics: Aged; alpha-Tocopherol; Antioxidants; Ascorbic Acid; Chromatography, High Pressure Liquid; Diabetes Mellitus; Female; Humans; Hyperlipidemias; Male; Myocardial Infarction

1. Fluvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, has been reported to decrease the oxidizability of plasma lipids in hyperlipidaemic subjects. In order to elucidate one of the mechanisms of this in vivo, we investigated the effects of fluvastatin and pravastatin on the decreased turnovers of reduced glutathione (GSH) and ascorbic acid (AA) in Watanabe heritable hyperlipidaemic (WHHL) rabbits. 2. These drugs (30 mg/kg per day) equally decreased plasma levels of lipids after a 4 week treatment period. However, only fluvastatin significantly decreased thiobarbituric acid-reactive substances, which were increased in the plasma of WHHL. 3. Although these drugs did not affect the steady state levels of total glutathione and low molecular weight thiols in the liver and kidney, fluvastatin markedly normalized the rate of GSH turnover in these tissues, as determined by using L-buthionine-(S,R)-sulphoximine, a specific inhibitor of GSH synthesis. 4. Fluvastatin also increased the clearance of AA from the circulation in WHHL. 5. These results suggest that, in addition to its hypolipidaemic action, fluvastatin has the potential to improve the turnover of anti-oxidants, which is closely related to the amelioration of the redox status in the body.

Topics: Animals; Anticholesteremic Agents; Antimetabolites; Ascorbic Acid; Buthionine Sulfoximine; Cholesterol; Fatty Acids, Monounsaturated; Fluvastatin; Glutathione; Glutathione Peroxidase; Glutathione Transferase; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hyperlipidemias; Indoles; Kidney; Liver; Male; Oxidation-Reduction; Phospholipids; Pravastatin; Rabbits; Thiobarbituric Acid Reactive Substances; Triglycerides

The combined effect of cyclophosphamide and ascorbic acid on plasma lipids and lipoprotein profiles are important since, ascorbic acid encumbered the lipid abnormalities initiated by cyclophosphamide during cancer chemotherapy. Hence, the study was launched to appraise the salutary role of ascorbic acid in cyclophosphamide administered fibrosarcoma bearing rats. Fibrosarcoma cell line induced rats were treated with cyclophosphamide (10 mg/kg body weight) and ascorbic acid (200 mg/kg body weight) individually and in combination for 28 days. The concentration of plasma lipids and lipoprotein profiles were determined in control and experimental animals. The untreated, as well as cyclophosphamide administered fibrosarcoma bearing rats, divulged significantly increased levels of plasma total cholesterol, triglycerides, phospholipids, VLDL- and LDL-cholesterol, as compared with their respective control animals. In contrast, ester and HDL-cholesterol levels exhibited a marked decrease in these animals. Similar observations were also noticed in liver lipid values, as well. However, these lipid abnormalities were corrected by the co-administration of ascorbic acid. These results suggested, that some clinical entanglement of cyclophosphamide was refrained by co-administration of ascorbic acid in tumor stress condition.

Topics: Animals; Ascorbic Acid; Cholesterol, LDL; Cholesterol, VLDL; Cyclophosphamide; Fatty Acids, Nonesterified; Fibrosarcoma; Hyperlipidemias; Lipid Metabolism; Male; Methylcholanthrene; Neoplasm Transplantation; Phospholipids; Rats; Rats, Wistar; Sarcoma, Experimental; Triglycerides

The present study was to investigate the levels of plasma lipid peroxide products including malondialdehyde (MDA) and conjugated dienes (CD), and antioxidants including enzyme superoxide dismutase, glutathione peroxidase, catalase, plasma vitamin E and vitamin C in diabetic patients. Fifty-eight diabetic subjects; 16 males and 42 females, aged 30-75 years, were recruited. Eighteen of them had diabetes and forty of them had diabetes with hyperlipidemia. Twenty-seven healthy subjects, 8 males and 19 females, aged 30-75 years, were used as the control group. The results showed that the concentrations of plasma MDA in diabetic patients with or without hyperlipidemia tended to be increased when compared to the controls but there were no significant differences. The CD values were increased significantly in both diabetic groups when compared with control subjects. Significantly elevated levels of plasma MDA and CD were found in diabetic patients with hypertriglyceridemia (> 150 mg%). This increment did not change the antioxidant status in both enzymes and vitamins except that the plasma vitamin E levels and the ratios of tocopherol: cholesterol were increased significantly. An increase of lipid peroxide in plasma may be one important factor in the development of vascular complication and atherosclerosis seen in diabetic patients.

Topics: Adult; Aged; Antioxidants; Arteriosclerosis; Ascorbic Acid; Cardiovascular Diseases; Catalase; Diabetes Mellitus; Female; Glutathione Peroxidase; Humans; Hyperlipidemias; Lipid Peroxidation; Male; Malondialdehyde; Middle Aged; Superoxide Dismutase; Vitamin E

The effects of ascorbic acid (AA) or vitamin C in atherosclerosis has attracted considerable attention; however results of clinical studies are conflicting. Several studies indicate an increase in plasma triglyceride (TG) and cholesterol (CH) levels in guinea pigs (GP) that have been fed a diet containing a minimal amount of AA. Previous studies carried out in GP fed a diet devoid of AA showed a significant decrease in cytochrome P-450 level compared to GP fed high and adequate amounts; however, the level of cytochrome P-450 in the two groups were not significantly different. The enzymes that synthesize TG and CH are located in endoplasmic reticulum which is also the site for cytochrome P-450 synthesis. It is of interest to determine whether there is an association between TG and CH synthesis and cytochrome P-450 induction. Adult male Hartley GP weighing 350-400 g were fed a diet containing 2.5% (Group I), 0.1% (Group II) and 0% (Group III) AA. The food consumption and weight gain were not significantly different in different groups. After feeding the diet for four weeks, half of the animals in each group were starved. Blood was withdrawn and TG and CH were determined in the serum. TG and CH were markedly elevated in both starved and nonstarved Group III GP; however, these levels were not altered in Group 1 and Group II GP. Plasma AA showed significant differences in all three nonstarved and starved groups. Plasma alpha-lipoprotein was decreased and beta-lipoprotein was increased in Group III GP. Hepatic CH and TG were also significantly elevated in Group III GP, and Groups I and II showed no changes. TG and CH showed a negative correlation with cytochrome P-450, whereas CH and TG showed a positive correlation. We conclude that AA deficiency causes extensive hyperlipidemia, feeding high level of AA does not alter the lipid metabolism and induction ofcytochrome P-450 is inversely related to TG and CH synthesis.

Topics: Animals; Ascorbic Acid; Ascorbic Acid Deficiency; Cholesterol; Cytochrome P-450 Enzyme System; Enzyme Induction; Guinea Pigs; Hyperlipidemias; Lipoproteins, HDL; Lipoproteins, LDL; Liver; Male; Triglycerides

The inhibition of lipoprotein catabolism after triton WR-1339 intravenous administration is associated with an impressive modification in the balance between plasma peroxidable substrates and antioxidants. Treated rat plasma and membrane lipids become peroxiaable when they are incubated with phenylhydrazine in standardized conditions and the production of thiobarbituric acid-reactive substances (lipoperoxidation markers) significantly increases. An accumulation of native lipoproteins which present a decreased alpha-tocopherol on triglycerid ratio and a modification in the plasmatic balance between alpha-tocopherol and ascorbate could explain these observations.

Topics: Animals; Ascorbic Acid; Disease Models, Animal; Erythrocytes; Fatty Acids; Humans; Hyperlipidemias; In Vitro Techniques; Lipid Peroxidation; Lipids; Male; Polyethylene Glycols; Rats; Rats, Wistar; Surface-Active Agents; Vitamin E

Graded amounts (0, 50, 500 and 5,000 mg/liter) of ascorbic acid (AsA) were given in drinking water to guinea pigs for 21 days to prepare AsA-deficient, low-AsA, moderate-AsA and excess-AsA animals, and the plasma phospholipid hydroperoxide level and lipid concentration were quantitatively determined to investigate the antioxidant effect of AsA in vivo. Phosphatidylcholine hydroperoxide (PCOOH) was a predominant phospholipid hydroperoxide present in the plasma, and the PCOOH concentration was significantly higher in AsA-deficient, low-AsA and excess-AsA animals (80.4 nM, 54.8 nM and 42.2 nM, respectively) as compared with that in moderate-AsA animals (27.2 nM). Hyperlipidemic plasma characterized as high cholesterol and high triacylglycerol concentrations was confirmed in AsA-deficient animals. Molar ratios of plasma AsA and alpha--tocopherol against 10(4) moles of phospholipids were significantly lower in AsA-deficient and low-AsA animals (0.6-2.1 and 5.5-8.5, respectively) than in moderate-AsA and excess-AsA animals (14.2-18.0 and 11.2-11.9, respectively). In plasma, a high correlation coefficient (r = 0.979) was observed between PCOOH and AsA for which there was optimum AsA level to keep the low PCOOH and such correlation was stronger than that (r = 0.558) observed with alpha-tocopherol. The results indicated that AsA has an important function to control the phospholipid hydroperoxide level in plasma and that moderate supplementation of AsA is required to reveal its optimal antioxidant effect in vivo. The present study also showed that AsA-deficiency especially invites an increase in plasma PCOOH together with a hyperlipidemic state which are risk factors in developing atherogenesis.

Topics: Animals; Ascorbic Acid; Ascorbic Acid Deficiency; Cholesterol; Drinking; Guinea Pigs; Hyperlipidemias; Lipids; Male; Phosphatidylcholines; Triglycerides; Vitamin E; Weight Gain

The effects of administration of guava and papaya fruit (100 g/day), vegetables, and mustard oil (5 g/day) (group A); antioxidant vitamins C (50 mg/day) and E (30 mg/day), plus betacarotene (10 mg/day) (group B); a high-fat (5-10 g/day) (group C); or a low-fat (4-5 g/day) diet (group D) were compared over 24 diet weeks in a randomized fashion, while all groups of rabbits (five in each of four groups) received a hydrogenated fat diet (5-10 g/day) for a period of 36 weeks. After 12 weeks on the high-fat diet, each group of rabbits had an increase in blood lipoproteins. The fruit and vegetable-enriched prudent diet (group A) caused a significant decline in blood lipids at 24 and 36 weeks, whereas the lipid levels increased significantly in groups C and D. Group A also had a significant rise in vitamin E (2.1 Umol/l), C (10.5 Umol/l), A (0.66 Umol/l), and carotene (0.08 Umol/l) and a decrease in lipid peroxides (0.34 nmol/ml at 36 weeks, whereas the levels were unchanged in groups C and D. Group B rabbits had a significant and greater increase than group A in plasma vitamins E, C, A, and carotene; a rise in HDL cholesterol; and a greater decrease in lipid peroxides after 24 and 36 weeks of treatment. After stimulation of lipid peroxidation in all rabbits, 3 of 5 group C and 2 of 5 group D rabbits died due to coronary thrombosis, whereas in groups A and B there were no deaths, indicating that antioxidant therapy can provide protection against lipid peroxidation and free radical generation. Aortic lipids and sudanophilia, indicating atherosclerosis, were significantly higher in groups C and D than in groups A and B. Fatty streaks and atheromatous and fibrous plaques were noted in all the rabbits in groups C and D. Intimal fibrosis and medial degeneration were also present in the group C rabbits. While group A (36.4 +/- 4.4 microns) and group B (37.1 +/- 4.2 microns) rabbits had minimal coronary artery plaque sizes, group C (75.4 +/- 10.6 microns) and group D rabbits (69.5 +/- 6.2 microns) had significantly greater plaque sizes. Aortic plaque sizes were also greater in groups C and D than in groups A and B. It is possible that combined therapy with antioxidant vitamins C, E, and carotene, and a diet rich in antioxidants, could independently inhibit free radical generation and the development of atherosclerosis.

Topics: Animals; Antioxidants; Arteriosclerosis; Ascorbic Acid; beta Carotene; Dietary Fats; Hyperlipidemias; Lipid Peroxidation; Oxidative Stress; Rabbits; Vitamin E

We report an impressive decline in plasma lipid resistance to oxidation during Triton-WR-1339-induced hyperlipidemia in rats. This decline is associated with a modification in the balances between alpha-tocopherol and lipids and alpha-tocopherol and ascorbate. These results are consistent with a weak resistance of accumulated native lipoproteins in plasma to oxidation, during a 6-hour time course, and they suggest a misunderstood role of lipoprotein catabolic enzymes: to improve this characteristic. Conclusively, the results lead us to propound Triton-induced hyperlipidemia as an original model for studying the balance impairment between antioxidants and oxidizable substrates.

Topics: Animals; Ascorbic Acid; Fatty Acids; Hyperlipidemias; Lipids; Lipoproteins; Male; Oxidation-Reduction; Polyethylene Glycols; Rats; Rats, Wistar; Surface-Active Agents; Vitamin E

Chronic vitamin C deficiency was induced in guinea pigs by restricting their vitamin C intake to 0.5 mg daily. This was just sufficient to prevent rapidly fatal scurvy and 55 per cent of the animals survived. In 16 weeks their serum ascorbic acid (SAA) fell to 0.16 +/- 0.06 mg/dl as compared to 0.73 +/- 0.11 in control animals receiving 5 mg vitamin C daily. There was a marked increase in serum cholesterol, LDL-cholesterol, VLDL-cholesterol, triglycerides and total lipids. HDL-cholesterol was, however, decreased resulting in a shift of the LDL/HDL ratio from 1.13 +/- 0.16 in the control to 5.91 +/- 1.70 in the low vitamin C group. Cholesterol feeding (100 mg/day) by itself lowered the SAA significantly, besides producing hyperlipidemia. When the vitamin C intake was reduced to only 0.5 mg/day, the effects of cholesterol feeding were exaggerated; the magnitude of hyperlipidemia was now significantly greater than with simple cholesterol feeding. The LDL/HDL ratio rose to 19.02 +/- 3.32 from 1.13 +/- 0.16 in the normal guinea pigs. Chronic vitamin C deficiency seems to affect the blood lipid profile unfavourably which could promote atherogenesis.

Topics: Animals; Ascorbic Acid; Ascorbic Acid Deficiency; Cholesterol; Cholesterol, Dietary; Cholesterol, LDL; Chronic Disease; Guinea Pigs; Hyperlipidemias; Lipids; Male; Triglycerides

Topics: Ascorbic Acid; Female; Humans; Hyperlipidemias; Lipids; Male; Middle Aged

Specialized "nutritional insurance" supplementation may reduce the risk of many important complications of long-term corticosteroid treatment. Supplementation with calcium, fluoride, activated vitamin D metabolites, and GTF, should help prevent osteoporosis. GTF, vitamin C, zinc and fluoride might help offset the inhibitory effect of corticosteroids on fibroblast and osteoblast function. Diabetic, hyperlipidemic and protein-losing effects might be compensated with supplementary GTF. Antioxidant nutrients could support humoral immunity and neutrophil function, while complementing the anti-inflammatory actions of corticosteroids. Supplementary magnesium could reduce the risk of nephrocalcinosis and nephrolithiasis.

Topics: Adrenal Cortex Hormones; Amino Acids; Ascorbic Acid; Chromium; Diabetes Mellitus; Double-Blind Method; Fluorides; Food, Fortified; Humans; Hydroxycholecalciferols; Hyperlipidemias; Immunologic Deficiency Syndromes; Nephrocalcinosis; Nicotinic Acids; Nutritional Requirements; Osteoporosis; Selenium; Silicon

Topics: Adult; Ascorbic Acid; Cholesterol; Humans; Hypercholesterolemia; Hyperlipidemias; Leukocytes; Middle Aged; Triglycerides

Topics: Animals; Ascorbic Acid; Biotin; Guinea Pigs; Hyperlipidemias; Lipid Metabolism; Pantothenic Acid; Rats; Vitamin E; Vitamins

Effects of L-ascorbate 2-sulfate (AAS) on fatty liver and hyperlipidemia induced by various treatments were studied in rats and guinea pigs. L-Ascorbic acid (AA) (50 or 175 mg/kg), a reference compound, lowered the lipid levels in the serum and/or liver in guinea pigs, while AA had little effect in rats. On the other hand, AAS (300 mg/kg) was effective in both animals. In rats, AAS lowered cholesterol and triglycerides in the serum from ethionine-treated animals and in the liver from orotic acid-supplemented animals. In guinea pigs, this compound lowered cholesterol and triglycerides in the serum from ethionine-treated animals, lipids in the liver from cholesterol-supplemented animals, and lipids in the serum and liver from scorbutic animals. AA markedly increased the content of AA in the organs in all experiments, while AAS had a slight effect. Thus, it is suggested that AAS exerts its hypolipidemic and lipotropic effects by the specific actions of AAS.

Topics: Animals; Ascorbic Acid; Cholesterol; Ethionine; Fatty Liver; Female; Guinea Pigs; Hyperlipidemias; Lipids; Male; Orotic Acid; Rats; Scurvy; Sulfuric Acids; Triglycerides

Topics: Ascorbic Acid; Humans; Hyperlipidemias; Renal Dialysis; Triglycerides

An addition of 5% citrus pectin and 0.5% ascorbic acid to high-fat diet of guinea pigs prevented total cholesterol accumulation in blood serum and the liver. Two groups of persons were given a preparation containing a daily dose of 15 g pectin and 450 mg ascorbic acid for 6 weeks. In 21 healthy persons with mild hypercholesterolemia total serum cholesterol dropped significantly by 24 mg/100 ml (8.6%), while the concentration of high density lipoprotein cholesterol remained unchanged. In 11 hyperlipemic outpatients (type IIa, IIb and IV) total serum cholesterol dropped by 68 mg/100 ml (18.7%). The changes in triglyceridemia proved inconsistent.

Topics: Animals; Anticholesteremic Agents; Ascorbic Acid; Cholesterol; Fasting; Guinea Pigs; Humans; Hypercholesterolemia; Hyperlipidemias; Lipoproteins, HDL; Liver; Male; Pectins; Reference Values; Triglycerides

Topics: Adult; Ascorbic Acid; Ascorbic Acid Deficiency; Cholesterol; Female; Humans; Hyperlipidemias; Leukocytes; Male; Middle Aged; Triglycerides

Effects of L-ascorbate 2-sulfate (AAS) on lipid metabolism were studied in guinea pigs maintained on diet I with sufficient L-ascorbic acid (AA) supplement or on diet II without AA supplement. AAS(300 mg/kg) inhibited an increase in serum and liver levels of lipids to a greater degree than AA (175 mg/kg), a reference compond, in hyperlipidemic guinea pigs induced by cholesterol feeding with diets I or II. AAS also induced a decrease in serum and liver levels of lipids in guinea pigs which had been previously maintained for 6 weeks on diet II containing 1.0% cholesterol. AA administration significantly increased AA level in various organs of animals maintained on both the diets containing cholesterol. It also rectified the AA level lowered by previous maintenance on diet II containing cholesterol. AAS showed a slight AA replacing effect on the AA level. Both AA and AAS exerted preventive and curative effects on several symptoms due to chronic AA deficiency.

Topics: Animals; Ascorbic Acid; Ascorbic Acid Deficiency; Depression, Chemical; Guinea Pigs; Hyperlipidemias; Lipid Metabolism; Lipids; Male; Time Factors

The effects of L-ascorbate 2-sulfate (AAS) on the lipid metabolism were examined in Triton-induced hyperlipemic mice, hypercholesterolemic and normal rats, the following results being obtained. 1) In Triton-induced hyperlipemic mice, AAS (300 mg/kg) significantly decreased the serum cholesterol level, while L-ascorbate (AA, 175 mg/kg) was found ineffective. 2)In hypercholesterolemic rats fed 0.5% cholesterol diet, the consecutive administration of AAS decreased the level of serum cholesterol and liver triacylglycerols. AA only slightly affected these levels. However, both AAS and AA prevented the unordinal increase in the liver weight caused by cholesterol feeding. 3)In normal rats, the administration of AAS over a 4-week period decreased the levels of serum cholesterol and liver triacylglycerols.

Topics: Animals; Anticholesteremic Agents; Ascorbic Acid; Cholesterol; Clofibrate; Dose-Response Relationship, Drug; Female; Hypercholesterolemia; Hyperlipidemias; Lipid Metabolism; Liver; Male; Mice; Polyethylene Glycols; Rats; Sex Factors; Triglycerides

Rabbits on a high cholesterol diet were divided into three groups: one group received subcutaneous injections of physiological saline 3 times/day, 5 days/wk for 10 wk; another group received subcutaneous injections of L-ascorbic acid (0.37 mmole) according to the same timetable; and the third group was administered an equivalent amount of L-ascorbate 2-sulfate as outlined above. Each week the serum levels of total and free cholesterol and triglycerides were measured. At the end of 10 wk the animals were killed and the cholesterol content of the livers, spleens, and adrenal glands was measured. The aortas were examined for plaque deposition; the deposits were excised and pooled according to groups; and the total mass and cholesterol contents of the pooled plaques were determined. Administration of ascorbic acid or ascorbate 2-sulfate did not prevent hypercholesterolemia or elevated levels of serum triglycerides. No significant differences among the groups were found either in tissue cholesterol levels or in the extent or type of lesions found. Although plaque deposition appeared to be similar in the aortas of these animals, a marked difference was found in total mass and cholesterol content of the plaques: The plaques of the saline-treated group had a total mass and cholesterol content approximately 2.5 times that found in the group injected with ascorbic acid and about 1.5 times that found in the animals treated with ascorbate 2-sulfate. These results indicate that ascorbic acid, in particular, minimizes the total quantity of plaque deposition even though it is ineffective in preventing hypercholesterolemia, elevated serum triglycerides, and accumulation of cholesterol by several tissues.

Topics: Adrenal Glands; Animals; Aorta; Arteriosclerosis; Ascorbic Acid; Cholesterol; Cholesterol, Dietary; Hypercholesterolemia; Hyperlipidemias; Liver; Male; Rabbits; Spleen; Sulfates; Triglycerides

Topics: Ascorbic Acid; Humans; Hyperlipidemias; Lipids

Topics: Ascorbic Acid; Azo Compounds; Bilirubin; Chemistry, Clinical; Diazonium Compounds; Epinephrine; Hemoglobins; Hemolysis; Histidine; Humans; Hyperlipidemias; Levodopa; Methyldopa; Norepinephrine; Rifampin; Spectrophotometry, Ultraviolet; Statistics as Topic; Tyrosine

Topics: Animals; Ascorbic Acid; Hyperlipidemias; Rabbits