ascorbic-acid and Dyslipidemias

Polycystic ovary syndrome (PCOS) is a heterogenous disorder characterized by chronic ovulation dysfunction and hyperandrogenism. It is considered the most common endocrinological disorder, affecting up to 25% of women of reproductive age, and associated with long-term metabolic abnormalities predisposing to cardiovascular risk, such as insulin resistance (IR), dyslipidemia, endothelial dysfunction, and systemic inflammation. PCOS is also characterized by elevated serum levels of luteinizing hormone (LH), causing a condition of hyperandrogenism and a consequent altered ratio between LH and the follicle stimulating hormone (FSH). Over the years, several different approaches have been proposed to alleviate PCOS symptoms. Supplementation with natural molecules such as inositols, resveratrol, flavonoids and flavones, vitamin C, vitamin E and vitamin D, and omega-3 fatty acids may contribute to overcoming PCOS pathological features, including the presence of immature oocyte, IR, hyperandrogenism, oxidative stress and inflammation. This review provides a comprehensive overview of the current knowledge about the efficacy of natural molecule supplementation in the management of PCOS.

Topics: Ascorbic Acid; Dietary Supplements; Dyslipidemias; Fatty Acids, Omega-3; Female; Flavanones; Flavonoids; Follicle Stimulating Hormone; Humans; Hyperandrogenism; Inositol; Insulin Resistance; Luteinizing Hormone; Ovulation; Polycystic Ovary Syndrome; Resveratrol; Vitamin D; Vitamin E; Vitamins

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

Vitamin C is a pivotal redox modulater in many biological reactions of which several remain poorly understood. Naturally, vitamin C has been the subject of many investigations over the past decades in relation to its possible beneficial effects on cardiovascular disease primarily based on its powerful yet general antioxidant properties. However, growing epidemiological, clinical and experimental evidence now suggests a more specific role of ascorbate in vasomotion and in the prevention of atherosclerosis. For example, in contrast to most other biological antioxidants, administration of vitamin C can apparently induce vasodilation. Millions of people worldwide can be diagnosed with vitamin C deficiency according to accepted definitions. In this perspective, the present review examines the evidence for a specific link between vitamin C deficiency and increased risk of atherosclerosis as well as the possible mechanisms by which vitamin C may exert its protective function.

Topics: Animals; Antioxidants; Ascorbic Acid; Ascorbic Acid Deficiency; Atherosclerosis; Coenzymes; Disease Models, Animal; Dyslipidemias; Endothelium, Vascular; Humans; Lipid Metabolism; Lipids; Nitric Oxide; Nitric Oxide Synthase; Scurvy; Vasodilation

Diabetes represents a serious risk factor for the development of cardiovascular problems such as coronary heart disease, peripheral arterial disease, hypertension, stroke, cardiomyopathy, nephropathy and retinopathy. Identifying the pathogenesis of this increased risk provides a basis for secondary intervention to reduce morbidity and mortality in diabetic patients. Hyperglycemia and protein glycation, increased inflammation, a prothrombotic state and endothelial dysfunction have all been implicated as possible mechanisms for such complications. A linking element between many of these phenomena could possibly be, among other factors, increased production of reactive oxygen species. Vascular endothelial cells have several physiological actions that are essential for the normal function of the cardiovascular system. These include the production of nitric oxide (NO), which regulates vasodilatation, anticoagulation, leukocyte adhesion, smooth muscle proliferation and the antioxidative capacity of endothelial cells. However, under conditions of hyperglycemia, excessive amounts of superoxide radicals are produced inside vascular cells and this can interfere with NO production leading to the possible complications. This article aims at reviewing the links between reactive oxygen species, diabetes and vascular disease and whether or not antioxidants can alter the course of vascular complications in diabetic patients and animal models. A possible beneficial effect of antioxidants might present a new addition to the range of secondary preventive measures used in diabetic patients.

Topics: alpha-Tocopherol; Animals; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Clinical Trials as Topic; Diabetes Complications; Dyslipidemias; Endothelium, Vascular; Glucose; Humans; Hyperglycemia; Hypertension; Insulin Resistance; Nitric Oxide; Oxidative Stress; Reactive Oxygen Species; Risk Factors; Vitamin E

The aim of the study was to explore the effects of n-3 polyunsaturated fatty acids (PUFA) supplementation in physiological doses on oxidative stress (OS) and dyslipidemia in patients on hemodialysis (HD).. Randomized, double-blind, controlled, experimental trial. A total of 88 HD patients ≥18 years old and on HD for at least 6 months. A total of 43 patients received 1.28 g/day of n-3 PUFA, and 45 other patients received soybean oil for 12 weeks. Both oil supplements were vitamin E standardized. Routine tests, lipid profile, advanced oxidation protein products, isoprostanes, vitamins C and E, total antioxidant capacity, serum fatty acids, and adverse effects were evaluated.. Supplementation was not able to alter lipid or OS profiles. There was an increase in the serum n-3 PUFA levels (eicosapentaenoic acid: +116%; docosahexaenoic acid: +100%) and an improvement in the n-6/n-3 ratio (-49%) in the supplemented group. Associations between n-3 PUFA and improvement in isoprostane and advanced oxidation protein product and HDL were observed. Treatment was well tolerated.. Although the n-3 PUFA supplementation was associated with lower concentrations of isoprostane and advanced oxidation protein product and higher HDL levels, it was not sufficient for the improvement of highly prevalent risk factors, such as OS and dyslipidemia in HD patients.

Topics: Adult; Aged; Ascorbic Acid; Blood Glucose; Cholesterol; Dietary Supplements; Docosahexaenoic Acids; Dose-Response Relationship, Drug; Double-Blind Method; Dyslipidemias; Eicosapentaenoic Acid; Fatty Acids, Omega-3; Female; Humans; Isoprostanes; Male; Middle Aged; Nutrition Assessment; Oxidative Stress; Renal Dialysis; Risk Factors; Serum Albumin; Triglycerides; Vitamin E

To evaluate the effect of long-term ingestion of mate tea, with or without dietary intervention, on the markers of oxidative stress in dyslipidemic individuals.. Seventy-four dyslipidemic volunteers participated in this randomized clinical trial. Subjects were divided into three treatment groups: mate tea (MT), dietary intervention (DI), and mate tea with dietary intervention (MD). Biochemical and dietary variables were assessed at the beginning of the study (baseline) and after 20, 40, 60, and 90 d of treatment. Participants in the MT and MD groups consumed 1 L/d of mate tea. Those in the DI and MD groups were instructed to increase their intake of fruit, legumes and vegetables and decrease their consumption of foods rich in cholesterol and saturated and trans-fatty acids. Biomarkers of oxidative stress such as antioxidant capacity of serum (ferric reducing antioxidant potential assay), uric acid, reduced glutathione, paraoxonase-1 enzyme, lipid hydroperoxide (LOOH), and protein carbonyl were analyzed.. Participants in the DI group showed a significant decrease in total fat and saturated fatty acid intakes. Those in the DI and MD groups presented a significant increase in vitamin C consumption. For all groups, there was a significant increase in ferric reducing antioxidant potential and reduced glutathione concentrations but no significant changes in LOOH, protein carbonyl, and paraoxonase-1 values. The reduced glutathione concentration was positively correlated with the consumption of monounsaturated fatty acids, fiber, and vitamin C, whereas levels of LOOH were inversely correlated with intakes of vitamin C and fiber. In addition, LOOH correlated positively with low-density lipoprotein cholesterol and inversely with high-density lipoprotein cholesterol, which had a positive association with paraoxonase-1.. The ingestion of mate tea independently of the dietary intervention increased plasma and blood antioxidant protection in patients with dyslipidemia.

Topics: Adult; Antioxidants; Aryldialkylphosphatase; Ascorbic Acid; Biomarkers; Cholesterol, HDL; Cholesterol, LDL; Diet; Dietary Fats; Dietary Fiber; Dyslipidemias; Energy Intake; Fatty Acids; Fatty Acids, Monounsaturated; Female; Glutathione; Humans; Ilex paraguariensis; Lipid Peroxides; Male; Middle Aged; Oxidative Stress; Phytotherapy; Plant Preparations; Protein Carbonylation

Clinical and experimental evidence suggests that hyperglycaemia is responsible for the oxidative stress in diabetes mellitus. The study was designed to investigate the comparative effects of probiotic and vitamin C (Vit-C) treatments on hyperglycaemia, oxidative stress and dyslipidaemia in alloxan-induced diabetic rats. Type 1 diabetes (T1DM) was induced in male Wistar rats by a single intraperitoneal (i.p.) injection of alloxan (150 mg/kg). Six groups of the animals received the following treatment regimens for four weeks: (1) Normal saline, per os; (2) alloxan (150 mg/kg, i.p.); (3) alloxan (150 mg/kg) + insulin (4 U/kg, subcutaneously); (4) alloxan (150 mg/kg) + probiotic (4.125 × 10⁶ CFU/100 mL per os); (5) alloxan (150 mg/kg) + Vit-C (100 mg/kg, i.m.); (6) alloxan (150 mg/kg) + probiotic (4.125 × 10⁶ CFU/100 mL per os) + Vit-C (100 mg/kg, intramuscularly). Probiotic + Vit-C decreased (p < 0.05) blood glucose concentration in diabetic treated group, when compared with the untreated diabetic group. Probiotic + Vit-C reduced malondialdehyde concentration, in the serum, brain and kidneys, respectively, but increased the activity of antioxidant enzymes. Probiotic and Vit-C may be more effective than Vit-C alone, in ameliorating hyperglycaemia, oxidative stress and dyslipidaemia in alloxan-induced diabetic rats.

Topics: Animals; Antioxidants; Ascorbic Acid; Blood Glucose; Diabetes Mellitus, Experimental; Dyslipidemias; Hyperglycemia; Insulin; Lipid Peroxidation; Male; Malondialdehyde; Oxidative Stress; Probiotics; Random Allocation; Rats; Rats, Wistar

Hitherto unknown efficacy of the peel extracts of Mangifera indica (MI), Cucumis melo (CM) and Citrullus vulgaris (CV) fruits in ameliorating the diet-induced alterations in dyslipidemia, thyroid dysfunction and diabetes mellitus have been investigated in rats. In one study, out of 4 different doses (50-300 mg/kg), 200 mg/kg of MI and 100 mg/kg for other two peel extracts could inhibit lipidperoxidation (LPO) maximally in liver. In the second experiment rats were maintained on pre-standardized atherogenic diet CCT (supplemented with 4% cholesterol, 1% cholic acid and 0.5% 2-thiouracil) to induce dyslipidemia, hypothyroidism and diabetes mellitus and the effects of the test peel extracts (200 mg/kg of MI and 100 mg/kg for CM and CV for 10 consecutive days) were studied by examining the changes in tissue LPO (in heart, liver and kidney), concentrations of serum lipids, thyroid hormones, insulin and glucose. Rats, treated simultaneously with either of the peel extracts reversed the CCT-diet induced increase in the levels of tissue LPO, serum lipids, glucose, creatinine kinase-MB and decrease in the levels of thyroid hormones and insulin indicating their potential to ameliorate the diet induced alterations in serum lipids, thyroid dysfunctions and hyperglycemia/diabetes mellitus. A phytochemical analysis indicated the presence of a high amount of polyphenols and ascorbic acid in the test peel extracts suggesting that the beneficial effects could be the result of the rich content of polyphenols and ascorbic acid in the studied peels.

Topics: Animals; Ascorbic Acid; Atherosclerosis; Blood Glucose; Citrullus; Creatine Kinase, MB Form; Cucumis melo; Diabetes Mellitus; Diet, Atherogenic; Dyslipidemias; Flavonoids; Fruit; Hyperglycemia; Hypoglycemic Agents; Hypothyroidism; Lipid Peroxidation; Lipids; Mangifera; Phenols; Phytotherapy; Plant Extracts; Polyphenols; Rats; Rats, Wistar; Thyroxine; Triiodothyronine

Serum CRP concentrations are elevated in subjects at risk of coronary events and in subjects with metabolic syndrome. Although dietary fat and antioxidants are known for their immune-modulating actions, their reported effects on CRP concentrations have been inconsistent. In the present study we have investigated whether dietary constituents are associated with serum CRP concentrations in healthy subjects and patients with dyslipidaemic. Dyslipidaemic subjects (n=238) were recruited from Hospital Outpatient Clinics in Guilford, UK. Apparently healthy subjects (n=188) were recruited from amongst adjacent University and Hospital employees. A validated food frequency questionnaire was used to estimate dietary intake. Dyslipidaemic patients had higher serum CRP [1.25 (0.42-3.26) mg/L] than control subjects [0.50 (0.17-1.42) mg/L] (p<0.001). In the dyslipidaemic patients, approximately 4% of the variation in serum CRP could be explained by dietary cholesterol intake (p = 0.015, 2.8%), and weakly by dietary vitamin C intake (p = 0.06, 1.2%). No relationship between dietary constituents and serum CRP concentrations was found among the healthy subjects. Hence the present study shows that serum CRP concentrations are increased in patients with classical coronary risk factors, and that they may be modulated by dietary cholesterol.

Topics: Ascorbic Acid; C-Reactive Protein; Case-Control Studies; Cholesterol, Dietary; Coronary Disease; Diet; Dyslipidemias; Exercise; Female; Humans; Male; Multivariate Analysis; Risk Factors; Smoking; Surveys and Questionnaires; United Kingdom; Vitamins

Amla (Emblica officinalis Gaertn.) is widely used in Indian medicine for the treatment of various diseases. We have investigated the effects of amla on the lipid metabolism and protein expression involved in oxidative stress during the ageing process. SunAmla or ethyl acetate extract of amla, a polyphenol-rich fraction, was administered at a dose of 40 or 10 mg/kg body weight per d for 100 d to young rats aged 2 months and aged rats aged 10 months. The lipid levels, such as cholesterol and TAG, in serum and liver were markedly elevated in aged control rats, while they were significantly decreased by the administration of amla. The PPARalpha is known to regulate the transcription of genes involved in lipid and cholesterol metabolism. The PPARalpha protein level in liver was reduced in aged control rats. However, the oral administration of amla significantly increased the hepatic PPARalpha protein level. In addition, oral administration of amla significantly inhibited the serum and hepatic mitochondrial thiobarbituric acid-reactive substance levels in aged rats. Moreover, the elevated expression level of bax was significantly decreased after the oral administration of amla, while the level of bcl-2 led to a significant increase. Furthermore, the expressions of hepatic NF-kappaB, inducible NO synthase (iNOS), and cyclo-oxygenase-2 (COX-2) protein levels were also increased with ageing. However, amla extract reduced the iNOS and COX-2 expression levels by inhibiting NF-kappaB activation in aged rats. These results indicate that amla may prevent age-related hyperlipidaemia through attenuating oxidative stress in the ageing process.

Topics: Aging; Animals; Ascorbic Acid; Body Weight; Cholesterol; Dyslipidemias; Eating; Flavonoids; Lipid Metabolism; Liver; Male; Oxidative Stress; Phenols; Phyllanthus emblica; Phytotherapy; Plant Extracts; Polyphenols; Proteins; Rats; Rats, Wistar; Triglycerides

Accelerated formation of advanced glycation/lipoxidation and endproducts (AGEs/ALEs) has been implicated in the pathogenesis of various diabetic complications. Several natural and synthetic compounds have been proposed and tested as inhibitors of AGE/ALE formation. We have previously reported the therapeutic effects of several new AGE/ALE inhibitors on the prevention of nephropathy and dyslipidemia in streptozotocin (STZ)-induced diabetic rats. In this study, we investigated the effects of various concentrations of a compound, LR-90, on the progression of renal disease and its effects on AGE and receptor for AGE (RAGE) protein expression on the kidneys of diabetic STZ-rats. Diabetic male Sprague-Dawley rats were treated with or without LR-90 (0, 5, 20, 25, and 50 mg/l of drinking water). After 32 weeks, body weight, glycemic status, renal function, and plasma lipids were measured. Kidney histopathology and AGE/ALE accumulation and RAGE protein expression in tissues were also determined. In vitro studies were also performed to determine the possible mechanism of action of LR-90 in inhibiting AGE formation and AGE-protein cross-linking. LR-90 protected the diabetic kidneys by inhibiting the increase in urinary albumin-to-creatinine ratio and ameliorated hyperlipidemia in diabetic rats in a concentration-dependent fashion without any effects on hyperglycemia. LR-90 treatment also reduced kidney AGE/ALE accumulation and RAGE protein expression in a concentration-dependent manner. In vitro, LR-90 exhibited general antioxidant properties by inhibiting metal-catalyzed reactions and reactive oxygen species (OH radical) and reactive carbonyl species (methlyglyoxal, glyoxal) generations without any effect on pyridoxal 5' phosphate. The compound also prevents AGE-protein cross-linking reactions. These findings demonstrate the bioefficacy of LR-90 in treating nephropathy and hyperlipidemia in diabetic animals by inhibiting AGE accumulation, RAGE protein expression, and protein oxidation in the diabetic kidney. Additionally, our study suggests that LR-90 may be useful also to delay the onset and progression of diabetic atherosclerosis as the compound can inhibit the expression of RAGE and inflammation-related pathology, as well as prevent lipid peroxidation reactions.

Topics: Animals; Ascorbic Acid; Body Weight; Butyrates; Cholesterol; Creatinine; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Dyslipidemias; Glycation End Products, Advanced; Glycosylation; Hydroxyl Radical; Hypoglycemic Agents; Kidney; Lipid Metabolism; Lipoproteins, LDL; Male; Molecular Structure; Oxidation-Reduction; Pyridoxal Phosphate; Rats; Rats, Sprague-Dawley; Receptor for Advanced Glycation End Products; Receptors, Immunologic; Triglycerides; Tyrosine

This study was aimed to evaluate the combined effect of curcumin with vitamin C supplementation on hyperglycemic and dyslipidemia conditions and endothelial cell dysfunction induced in diabetic rats. Wistar Furth rats were used and divided into four groups: control (single injection of 0.9% sterile saline), STZ (streptozotocin, Sigma, 55 mg/kg.BW, i.v.), STZ-vitC (1 g/l ascorbic acid mixed in drinking water), STZ-cur (daily oral treatment of 300 mg/kg.BW curcumin; Cayman Chemical Co., USA), and STZ-cur+vitC (1 g/l ascorbic acid mixed in drinking water and oral treatment of 300 mg/kg.BW curcumin). On 8th week after STZ-injection, the microcirculation in the iris tissue was observed using intravital fluorescence videomicroscopy, and also leukocyte adhesion in the venule was examined for each group. Blood glucose (BG), lipid profiles, glycosylated hemoglobin (HbA1c) were measured in blood samples collected at the end of each experiment. The contents of liver malondialdehyde (MDA) were also quantified for each group. Feeding curcumin (STZ-cur) could decrease BG, HbA1c, dyslipidemia, and MDA significantly, compared to STZ. In cases of feedings curcumin with vitamin C, these results were more effective in all aspects, including leukocyte adhesion. In conclusion, curcumin might increase the effect of vitamin C in protecting the function of endothelial cells through its anti-oxidant with hypoglycemic and hypolipidemic actions.

Topics: Animals; Ascorbic Acid; Blood Glucose; Curcumin; Diabetes Complications; Diabetes Mellitus, Experimental; Dyslipidemias; Endothelium, Vascular; Hyperglycemia; Iris; Laser-Doppler Flowmetry; Leukocyte Rolling; Lipoproteins; Male; Microcirculation; Microscopy, Video; Rats; Rats, Inbred WF

The serum vitamins A, E, and C (antioxidant vitamins) of 112 priest subjects, compared with 90 males and 119 females in a control group, were investigated. Subjects for the study were Thai volunteers who attended the Outpatient Department, Priest Hospital, Bangkok, for a physical check-up from July to September 2003. There was no age difference between the priest group and the controls. All serum vitamins, A, E, and C, of the priest group were significantly lower than the control group. Statistically significantly higher levels of total cholesterol, LDL-C, and LDL-C/HDL-C ratio were found in the priest subjects compared with the controls. The median serum retinol concentration in the priest subjects was 3.02 micromol/l (range 1.47-4.01 micromol/l) compared with 3.23 micromol/l (range 1.74-4.57 micromol/l) in the controls (p<0.01). The median serum a-tocopherol concentration in the priest subjects was 18.1 mmol/l (range 5.8-27.3 micromol/l) compared with 19.6 mmol/l (range 7.3-37.7 micromol/l) in the controls (p<0.01). The median serum ascorbic acid concentration in the priest subjects was 3.74 mg/l (range 0.0-17.0 mg/l) compared with 6.37 mg/l (range 0.0-18.0 mg/l) in the controls. The median values for retinol, alpha-tocopherol, and ascorbic acid serum concentrations in the male priests were lower than the control males. A total of 28% and 65% of the priest subjects had decreased alpha-tocopherol and ascorbic acid levels, while the controls had decreased alpha-tocopherol and ascorbic acid levels of 20% and 31.5%, respectively. A total of 67.8% and 54.4% of priest and control subjects, respectively, had cholesterol concentrations of > or = 5.18 mmol/l. However, a prevalence of low HDL-C (HDL-C < or = 0.91 micromol/l) was found in 1.8% of priest subjects and 1.4% of controls. Statistically significant associations were found between alpha-tocopherol, cholesterol, LDL-C, triglyceride, and serum retinol. A positive correlation was found between age, retinol, and serum alpha-tocopherol. A negative correlation was found between cholesterol, HDL-C, LDL-C, and the serum alpha-tocopherol/cholesterol ratio. In addition, negative correlations were found between weight, cholesterol, LDL-C, triglyceride, and the serum alpha-tocopherol/(cholesterol + triglyceride) ratio in priest and control subjects. The results suggest more research should be conducted into the health and nutritional problems of both healthy and diseased priest subjects concerning vitamins and oxida

Topics: Adult; Aged; Antioxidants; Ascorbic Acid; Buddhism; Case-Control Studies; Diet; Dyslipidemias; Energy Intake; Energy Metabolism; Female; Humans; Lipids; Male; Middle Aged; Nutritional Physiological Phenomena; Thailand; Vitamin A; Vitamin E