ascorbic-acid and Disease

Beyond its general role as antioxidant, specific functions of ascorbate are compartmentalized within the eukaryotic cell. The list of organelle-specific functions of ascorbate has been recently expanded with the epigenetic role exerted as a cofactor for DNA and histone demethylases in the nucleus. Compartmentation necessitates the transport through intracellular membranes; members of the GLUT family and sodium-vitamin C cotransporters mediate the permeation of dehydroascorbic acid and ascorbate, respectively. Recent observations show that increased consumption and/or hindered entrance of ascorbate in/to a compartment results in pathological alterations partially resembling to scurvy, thus diseases of ascorbate compartmentation can exist. The review focuses on the reactions and transporters that can modulate ascorbate concentration and redox state in three compartments: endoplasmic reticulum, mitochondria and nucleus. By introducing the relevant experimental and clinical findings we make an attempt to coin the term of ascorbate compartmentation disease.

Topics: Animals; Ascorbic Acid; Cell Compartmentation; Disease; Gene Expression Regulation; Humans; Models, Biological; Organelles

The mammalian thioredoxin reductases (TrxRs) are a family of selenium-containing pyridine nucleotide-disulphide oxidoreductases with mechanistic and sequence identity, including a conserved -Cys-Val-Asn-Val-Gly-Cys- redox catalytic site, to glutathione reductases. TrxRs catalyse the NADPH-dependent reduction of the redox protein thioredoxin (Trx), as well as of other endogenous and exogenous compounds. The broad substrate specificity of mammalian TrxRs is due to a second redox-active site, a C-terminal -Cys-SeCys- (where SeCys is selenocysteine), that is not found in glutathione reductase or Escherichia coli TrxR. There are currently two confirmed forms of mammalian TrxRs, TrxR1 and TrxR2, and it is possible that other forms will be identified. The availability of Se is a key factor determining TrxR activity both in cell culture and in vivo, and the mechanism(s) for the incorporation of Se into TrxRs, as well as the regulation of TrxR activity, have only recently begun to be investigated. The importance of Trx to many aspects of cell function make it likely that TrxRs also play a role in protection against oxidant injury, cell growth and transformation, and the recycling of ascorbate from its oxidized form. Since TrxRs are able to reduce a number of substrates other than Trx, it is likely that additional biological effects will be discovered for TrxR. Furthermore, inhibiting TrxR with drugs may lead to new treatments for human diseases such as cancer, AIDS and autoimmune diseases.

Topics: Animals; Ascorbic Acid; Cell Division; Disease; Gene Expression Regulation, Enzymologic; Humans; Oxidative Stress; Selenium; Selenocysteine; Thioredoxin-Disulfide Reductase; Tumor Suppressor Protein p53

Topics: Ascorbic Acid; Chronic Disease; Diet; Disease; Epidemiologic Methods; Female; Fruit; Humans; Male; Neoplasms; Preventive Medicine; Risk Factors; Vegetables

This paper presents a review of the significant body of literature liking dietary iron overload, not only to heart disease, but also to cancer, diabetes, osteoporosis, arthritis, and possibly other disorders. Following an analysis of our understanding of the mechanistic role iron plays in oxidative damage, an interpretation of the fact that plasma concentrations of several antioxidants are decreased in the presence of disease is offered. Evaluation of (1) age-related dietary trends over time and (2) factors involved in iron absorption leads to the hypothesis that the combination of citric acid and ascorbic acid (a synergistic pair of strong enhancers) is instrumental in causing a deleterious increase in iron load in aging populations. Iron overload may be the most important common etiologic factor in the development of the diseases mentioned; therefore, the synergistic combination of citric and ascorbic acids may play a major role in our worsening disease statistics. Evidence to support this hypothesis and possible experiments to test it are included. This combination needs further study, particularly because the iron overload produced may be correctable.

Topics: Aging; Ascorbic Acid; Citrates; Citric Acid; Diet; Disease; Free Radicals; Heart Diseases; Humans; Intestinal Absorption; Iron; Neoplasms

Topics: Adult; Aged; Ascorbic Acid; Asthma; beta Carotene; Clinical Trials as Topic; Clinical Trials, Phase I as Topic; Coronary Disease; Disease; Disease Susceptibility; Epidemiologic Factors; Female; Heart Transplantation; Humans; Incidence; Male; Men; Middle Aged; Neoplasms; Pregnancy; Prognosis; Pulmonary Disease, Chronic Obstructive; Risk Factors; Sex Factors

To monitor the incidence of dry socket in a sample of 696 consecutive tooth extraction patients and to test the possible therapeutic effects of vitamin C.. Following standardized extractions, 24 dry socket patients were provided 4,000 mg/day dosages of Vitamin C. Demographic and health history data were collected.. The occurrence of dry socket (3.5% overall) was greater in females and individuals with lower overall health status, and supplemental Vitamin C was associated with rapid recovery.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Antioxidants; Ascorbic Acid; Child; Disease; Dry Socket; Female; Health Status; Humans; Hypersensitivity; Male; Middle Aged; Retrospective Studies; Sex Factors; Smoking; Tooth Extraction

The concentration of antioxidants in human blood plasma is important in investigating and understanding the relationship between diet, oxidant stress, and human disease. The HPLC-EC technique combines selectivity with high sensitivity for measuring both water- and lipid-soluble antioxidants. The excellent sensitivity of the methods described here allows one to measure a panel of antioxidants in a small volume of plasma.

Topics: Antioxidants; Ascorbic Acid; beta Carotene; Bilirubin; Blood Chemical Analysis; Blood Proteins; Carotenoids; Chromatography, High Pressure Liquid; Diet; Disease; Electrochemistry; Humans; Indicators and Reagents; Lycopene; Sulfhydryl Compounds; Ubiquinone; Uric Acid; Vitamin E

This is a brief, conversational summary of oral contraceptive and drug interactions, giving theory and examples. To understand how drugs may compete in the body their paths must be known. The steroids in the pill are first partially inactivated in the intestine, and then absorbed into the blood going to the liver for more processing. Some antibiotics (e.g. ampicillin and tetracycline) are themselves not absorbed very well, occasionally indicating this by diarrhea, so that the steroids are also not absorbed. Often comparable well absorbed antibiotics are available (e.g. amoxicillin and doxycycline). Other antibiotics (e.g. neomycin, chloramphenicol, griseofulvin, sulfonamides, nitrofurantoin) kill intestinal bacteria whose enzymes help steroid absorption. These may cause contraceptive failure especially of low dose pills. A classic series of drugs (e.g. some antihistamines, sedatives and tranquilizers) induces drug inactivating enzymes in the liver that will also inactivate pill steroids. If these are used chronically, pill dose should be raised. The tuberculosis drug rifampin also may wipe out the effect of low dose orals. The steroids in the pill may reduce the clearance of drugs, particularly the asthma medications theophylline, and aminophylline, causing toxicity. The dose of these must be reduced as much as 33%. Similarly, Valium and Librium may last longer or overdose in pill users Neuroleptic drugs can stress the liver enough to cause jaundice in this manner. Self-administered drugs and vitamins, notably vitamin C can also cause drug interactions, especially if they are use irregularly. For example suddenly stopping a high ascorbic acid intake can cause pregnancy.

Topics: Anti-Bacterial Agents; Ascorbic Acid; Biology; Contraception; Contraception Behavior; Contraceptive Agents; Contraceptive Agents, Female; Contraceptives, Oral; Contraceptives, Oral, Hormonal; Disease; Family Planning Services; Metabolism; Pharmaceutical Preparations; Physiology; Steroids; Therapeutics; Vitamins

Although most researchers are concerned with the major side effects of oral contraceptives, swelling, nausea, depression, poor circulation, and weight gain are labeled ''minor'' and ignored. A few researchers have found that these side effects seem related to nutritional depletion in oral contraceptive users, especially: 1) Vitamin-B6, which is linked to depression and tryptophan level abnormalities in pill users and may be associated with nausea and weight gain. Studies show a daily need 10-30 times greater than that for women not on the pill. 2) Folic acid deficiency, common among women but a 25% deficiency rate has been noted in pill users. This has been associated with cell malformation and may be a reason for the high spontaneous abortion rate in women who conceive immediately after discontinuing the pill. 3) B1 and B12, the vitamins affecting energy, skin, and hair. Although not linked to any side effects, levels are low in pill users. 4) Vitamin-C, definitely depleted in pill users. This may be part of the bodily change resulting in cardiac problems and thrombosis. Full vitamin supplementation is recommended for all women taking oral contraceptives, including these vitamins as well as Vitamin-E and bioflavinoids. Vitamin supplements are routine for pregnancy. They should also be routine for the pseudopregnancy of oral contraception.

Topics: Anthropometry; Ascorbic Acid; Biology; Body Weight; Central Nervous System; Child Development; Contraception; Contraceptives, Oral; Depression; Digestive System; Disease; Family Planning Services; Growth; Mental Disorders; Nausea; Physiology; Signs and Symptoms; Vitamin A; Vitamin B Complex; Vitamins

Topics: Aminopyrine; Ascorbic Acid; Bone Diseases; Caffeine; Disease; Joint Diseases; Muscle Relaxants, Central; Muscle Relaxation; Muscles; Muscular Diseases; Vitamins

Topics: Ascorbic Acid; Disease; Humans; Hypoparathyroidism; Parathyroid Diseases; Parathyroid Glands; Vitamin D; Vitamins

Topics: Ascorbic Acid; Disease; Humans; Hypoparathyroidism; Parathyroid Diseases; Parathyroid Glands; Vitamin D; Vitamins

Topics: Ascorbic Acid; Climacteric; Disease; Epistaxis; Female; Flavonoids; Hesperidin; Humans; Leg; Muscle Cramp; Sleep-Wake Transition Disorders; Vitamins

Topics: Aged; Ascorbic Acid; Disease; Folic Acid; Humans; Procaine; Vitamin B Complex

Topics: Aged; Ascorbic Acid; Disease; Folic Acid; Humans; Procaine; Vitamin B Complex; Vitamins

Topics: Ascorbic Acid; Cataract; Dehydroascorbic Acid; Disease; Eye; Humans; Inflammation; Uvea

Topics: Aged; Ascorbic Acid; Asthenia; Disease; Humans; Inositol; Magnesium; Vitamins

Topics: Ascorbic Acid; Disease; Gingiva; Gingival Diseases; Humans; Scurvy; Vitamins

Topics: Aged; Ascorbic Acid; Chronic Disease; Disease; Humans; Vitamins

Topics: Ascorbic Acid; Chlortetracycline; Disease; Humans; Periodontal Diseases; Periodontitis; Periodontium; Tocopherols; Vitamin E; Vitamins

Topics: Aged; Ascorbic Acid; Disease; Humans; Middle Aged; Research; Scurvy; Vitamins

Topics: Ascorbic Acid; Disease; Ear Diseases; Otolaryngology; Pharyngeal Diseases; Pharynx

Topics: Ascorbic Acid; Disease; Humans; Leg; Restless Legs Syndrome; Vitamins

Topics: Arthritis, Rheumatoid; Ascorbic Acid; Desoxycorticosterone; Desoxycorticosterone Acetate; Disease; Humans; Osteoarthritis; Sciatic Nerve; Sciatica; Spondylitis

Topics: Ascorbic Acid; Blood Circulation; Cardiovascular Diseases; Disease; Hematologic Diseases; Humans; Physiological Phenomena; Vitamins

Topics: Ascorbic Acid; Disease; Humans; Mucous Membrane; Skin Diseases; Vitamin A; Vitamins

Topics: Ascorbic Acid; Disease; Gingiva; Humans

Topics: Ascorbic Acid; Carbamoyl-Phosphate Synthase I Deficiency Disease; Deficiency Diseases; Disease; Drinking Behavior; Extremities; Feeding and Eating Disorders; Humans; Thiamine

Topics: Ascorbic Acid; Ascorbic Acid Deficiency; Disease; Gingiva; Gingival Diseases; Gingivitis; Humans

Topics: Ascorbic Acid; Ascorbic Acid Deficiency; Disease; Gingiva; Gingival Diseases; Gingivitis; Humans

Topics: Ascorbic Acid; Disease; Gingiva; Humans; Tooth Extraction; Wound Healing