| Competitive Bodybuilder
Geregistreerd: Dec 2004 Locatie: Nederland Leeftijd: 34 Geslacht: M
Posts: 1.654
| Vitamine C: Een overzicht van de menselijke studies (in vivo)!!
Ik denk dat ik voor de topics die ik behandel een sufficient aantal studies heb bekeken om er een realistisch beeld over te geven. Wederom haal ik zowel positieve als negatieve studies aan om een objectief beeld te geven.
(Ik maak mezelf echter geen illusies dat dit alle studies zijn).
Heb dit voor een amerikaans board gemaakt, maar ga het echt niet allemaal in het nederlands vertalen. Vette pech  CONTENT:
-Vitamine C in exercise.
The majority of studies show a positive effect from vit C on exercise. -Vitamin C and the immune system
The majority of studies show a positive effect from vit C (sometimes in synergy with other substances/antioxidants on the immune system) -Vitamin C and the liver
Vitamine C only or combined with vit E may be beneficial for treating various forms of liver stress. -Vitamin C and the heart.
The majority of studies show no- or a minor significant positive effect from vit C on CHD, but vit C may be of value for some specific heart problems. -Other interesting studies -Side effects
No side effects from vitamin C (except for possible gastrointestinal upset) are reported in doses up to 2 (possibly 4) g. There is no clear establishment of vit C as a possible risk factor for calcium oxalate stones. Furthermore vit C does not show pro-oxidant effects (at least in doses up to 5 g) in human in vivo studies.
Vitamin E supplementation in doses higher than those used in multivitamine pills may have a negative impact on vascular disorders.
Vitamin A should be avoided by people with liver disorders.
Vitamin supplementation by pregant women is discouraged. VITAMIN C IN EXERCISE
A)Studies showing an adverse effect from vit C on exercise (1x).
B)Studies showing no effect from vit C on exercise (4x).
C)Studies showing a positive effect from vit C on exercise (6x).
D)Studies showing an adverse effect from vit C + other antioxidants on exercise (1x).
E)Studies showing no effect from vit C + other antioxidants on exercise (3x).
F)Studies showing a positive effect from vitamine C + other antioxidants on exercise (8x).
A)Studies showing an adverse effect from vit C on exercise: Citaat: Influence of vitamin C supplementation on oxidative and salivary IgA changes following an ultramarathon. = probably the same study as:
Influence of vitamin C supplementation on oxidative and immune changes after an ultramarathon.
500 mg vit C supplemented 3 times/day for 7 weeks prior to an ultramarathon in 15 subjects. During the race, runners received 1 l/h carbohydrate beverages (60 g/l) with vitamin C (150 mg/l) or without in a double-blinded fashion.
No significant correlations were found between post-race plasma vitamin C, oxidative, and saliva measures, except for a positive correlation between post-race serum cortisol and serum vitamin C (r=0.50, P=0.006) (Note from author: there was no difference in serum cortisol during the marathon after 32 km between the vit C and placebo group > http://jap.physiology.org/cgi/conten...l/92/5/1970/T3) (A502).
| B)Studies showing no effect from vit C on exercise: Citaat: Vitamin C supplementation does not alter the immune response to 2.5 hours of running.
1000 mg vit C for 8 days in experienced marathon runners had no significant effect on cortisol and catecholamines; leukocyte subsets; interleukin-6; natural killer cell activity; lymphocyte proliferation as induced by concanavalin A, phytohemagglutinin, and pokeweed mitogen; and granulocyte phagocytosis and activated oxidative burst (A509).
| Citaat: Prolonged vitamin C supplementation and recovery from eccentric exercise.
200 mg vit C 2x/day for 14 days before (and 3 d after) 30 min. downhill running does not decrease muscle soreness and muscle damage (creatine kinase activity and myoglobin concentration), and interleukin-6 concentrations (A517).
| Citaat: Post-exercise vitamin C supplementation and recovery from demanding exercise.
200 mg vit C following an unaccustomed bout of exercise, followed by an additional 200 mg later that day + 2x/day for the following 2 days did not improve recovery. Post-exercise serum creatine kinase activities and myoglobin concentrations were unaffected by supplementation (A519).
| Citaat: Muscle soreness and damage parameters after prolonged intermittent shuttle-running following acute vitamin C supplementation.
Nine habitually active males consumed 1 g vit C 2 h before a 90 min intermittent shuttle-running test, and on another occasion consumed an identical placebo.
Muscle soreness, and markers of both muscle damage (creatine kinase and aspartate aminotransferase) and lipid peroxidation (malondialdehyde) were elevated to an equal extent after exercise in placebo and supplemented trials (A524).
| C)Studies showing a positive effect from vit C on exercise: Citaat: Prolonged vitamin C supplementation and recovery from demanding exercise.
200 mg vit C 2 x/day 14 days prior to a 90 min. unaccustomed shuttle run in 8 subjects: Post-exercise serum creatine kinase activities and myoglobin concentrations were unaffected by supplementation. However, vitamin C supplementation had modest beneficial effects on muscle soreness, muscle function, and plasma concentrations of malondialdehyde. Furthermore, although plasma interleukin-6 increased immediately after exercise in both groups, values in the VC group were lower than in the P group 2 hours after exercise (p < .05) (A504).
| Citaat: Vitamin C supplementation attenuates the increases in circulating cortisol, adrenaline and anti-inflammatory polypeptides following ultramarathon running.
The study demonstrates an attenuation, albeit transient, of both the adrenal stress hormone and anti-inflammatory polypeptide response to prolonged exercise in runners who supplemented with 1500 mg vitamin C per day when compared to < or = 500 mg per day (for 7 days before the race)(A505).
| Citaat: Attenuation of increase in circulating cortisol and enhancement of the acute phase protein response in vitamin C-supplemented ultramarathoners.
500 mg vit C 2 x/day for 7 days in 10 ultramarathon athletes significantly increased C-reactive protein and decreased cortisol by 30% post race (A507).
| Citaat: Influence of vitamin C supplementation on cytokine changes following an ultramarathon.
500 mg vit C (10 subjects) or 1500 mg (12 subjects) for 7 days before an ultramarathon: Cortisol increased in all groups immediately after the race but significantly less in the vit C-1500 group. Runners experienced strong increases in concentrations of plasma IL-6, IL-10, IL-1RA, and IL-8. These increases were attenuated in runners ingesting 1500 mg but not 500 mg vitamin C (A508).
| Citaat: An effect of ascorbic acid on delayed-onset muscle soreness.
Delayed-onset muscle soreness following strenuous use of the posterior calf muscles was studied to determine if ascorbic acid might have an effect on the appearance of this familiar pain. A double-blind, randomized, crossover study compared the soreness in subjects taking ascorbic acid against those taking a lactose placebo. Visual analog scales were used in conjunction with a variety of pain-challenging methods, and the results indicated a significant difference between experimental and placebo groups at the height of soreness. Typical soreness abatement scores of 25-44% were observed. A sample size of 19, lack of an untreated control group as well as the singular nature of the exercise and its intensity were considered limitations of the study (A529).
| Citaat: Exercise-induced endotoxemia: the effect of ascorbic acid supplementation.
Strenuous short-term aerobic exercise results in significant increases in plasma LPS levels (endotoxemia) together with increases in markers of oxidative stress. Supplementation with ascorbic acid (1000 mg), however, abolished the increase in LPS and nitrite but led to a significant increase in the ascorbate radical in plasma (A539).
| D)Studies showing an adverse effect from vit C + other antioxidants on exercise Citaat: Supplementation with vitamin C and N-acetyl-cysteine increases oxidative stress in humans after an acute muscle injury induced by eccentric exercise.
There has been no investigation to determine if the widely used over-the-counter, water-soluble antioxidants vitamin C and N-acetyl-cysteine (NAC) could act as pro-oxidants in humans during inflammatory conditions. We induced an acute-phase inflammatory response by an eccentric arm muscle injury. The inflammation was characterized by edema, swelling, pain, and increases in plasma inflammatory indicators, myeloperoxidase and interleukin-6. Immediately following the injury, subjects consumed a placebo or vitamin C (12.5 mg/kg body weight) and NAC (10 mg/kg body weight) for 7 d.
Lactate dehydrogenase, creatine kinase, lipid hydroperoxides and 8-Iso-PGF2alpha were elevated to a greater extent in the vitamin C and NAC group.
This acute human inflammatory model strongly suggests that vitamin C and NAC supplementation immediately post-injury, transiently increases tissue damage and oxidative stress (A522).
| E)Studies showing no effect from vit C + other antioxidants on exercise: Citaat: Effect of Vitamin C and E supplementation on biochemical and ultrastructural indices of muscle damage after a 21 km run.
Vitamin C and E supplementation (500 or 1000 mg or IU per day) for four weeks does not reduce either biochemical or ultrastructural indices of muscle damage in experienced runners after a half marathon(A520).
| Citaat: Effect of vitamin supplementation on cytokine response and on muscle damage after strenuous exercise.
Twenty male recreational runners randomly received either antioxidants (500 mg of vitamin C and 400 mg of vitamin E) or placebo for 14 days before and 7 days after a 5% downhill 90-min treadmill run. The two groups showed identical exercise-induced changes in cytokine, muscle enzyme, and lymphocyte subpopulations. The plasma level of interleukin (IL)-6 and IL-1 receptor antagonist increased 20- and 3-fold after exercise. The plasma level of creatine kinase was increased sixfold the day after exercise(A523).
| Citaat: No effect of antioxidant supplementation in triathletes on maximal oxygen uptake, 31P-NMRS detected muscle energy metabolism and muscle fatigue.
Seven male triathletes received daily oral antioxidant supplementation in capsule form including 100 mg coenzyme Q10 (CoQ10), 600 mg ascorbic acid and 270 mg alpha-tocopherol or placebo over a 6-week interval.
The results demonstrate no effect of antioxidative vitamin supplementation on maximal oxygen uptake, muscle energy metabolism or muscle fatigue in triathletes (A525).
| F)Studies showing a positive effect from vitamine C + other antioxidants on exercise: Citaat: Supplementation with vitamins C and E inhibits the release of interleukin-6 from contracting human skeletal muscle
Contracting human skeletal muscle is a major contributor to the exercise-induced increase of plasma interleukin-6 (IL-6).
Supplementation of vitamins C (500 mg/d) and E (400 i.u./d) for 28 days to 7 healthy men attenuated the systemic IL-6 response to exercise primarily via inhibition of the IL-6 protein release from the contracting skeletal muscle per se. Plasma interleukin-1 receptor antagonist (IL-1ra), C-reactive protein and cortisol levels all increased after the exercise in Control, but not in Treatment (A501).
| Citaat: Effects of alpha-tocopherol, beta-carotene and ascorbic acid on oxidative, hormonal and enzymatic exercise stress markers in habitual training activity of professional basketball players.
600 mg alpha-tocopherol, 1000 mg vit C, and 32 mg beta-carotene for 35 days in 13 professional basketball players decreases plasma lipid peroxides by 27.7%. A significant decrease of lactate dehydrogenase serum activity was observed during the 24 h recuperation time. During this time the anabolic/catabolic balance increased about 29.8% in the antioxidant supplemented group, although this increase did not reach statistical significance (A506).
| Citaat: Effects of dietary supplementation with vitamins C and E on muscle function during and after eccentric contractions in humans.
500 mg of vitamin C and 1,200 IU of alpha-tocopherol/day for 37 days in 12 volunteers: After 30 days of treatment, volunteers performed 300 maximal eccentric contractions of the knee extensor muscles of one leg.
Prior supplementation with dietary antioxidants ameliorates muscle functional decrements subsequent to eccentric muscle contraction. Both groups experienced similar significant muscle soreness and swelling after exercise (A515).
| Citaat: Effects of antioxidant therapy in women exposed to eccentric exercise.
18 women randomized to antioxidants or placebo before a bout of eccentric exercise: Antioxidants attenuated the creatine kinase activity and muscle soreness responst to the EE, with little impact on maximal isometric force and range of motion (A516).
| Citaat: Antioxidant supplementation preserves antioxidant response in physical training and low antioxidant intake.
An antioxidant mixture (Se 150 microg, retinyl acetate mg, ascorbic acid 120 mg, alpha-tocopheryl succinate 20 mg) for 7 thriathletes (10 control subjects) in a controlled double blind study alleviated muscle damage during 4 weeks of overloaded training followed by 4 weeks of normal training. The effects of the antioxidant mixture were observed for doses that can be provided by a diversified and well-balanced diet (A518).
| Citaat: Lipid peroxidation and antioxidative vitamins under extreme endurance stress.
A randomized and placebo-controlled study on 24 trained long-distance runners substituted with alpha-tocopherol (400 I.U. d-1) and vit C (200 mg d-1) during 4.5 weeks prior to a marathon race.
The increase of CK serum concentration is remarkably lower in the supplemented group compared with the placebo group (P < 0.01) (A526).
| Citaat: Protective effect of vitamin E on exercise-induced oxidative damage in young and older adults.
21 men reveived 800 IU dl-alpha-tocopherol or placebo for 48 days before a bout of eccentric exercise in a double blind protocol.
The alterations in fatty acid composition, vitamin E, and lipid conjugated dienes in muscle and in urinary lipid peroxides in controls after eccentric exercise are consistent with the concept that vitamin E provides protection against exercise-induced oxidative injury (A527).
| Citaat: Effect of antioxidant vitamin supplementation on muscle function after eccentric exercise.
24 physically young subjects ingested either placebo (n=8), Vit E (400 mg; n=8) or vit C (400 mg; n=8) for 21 days prior to and for 7 days after performing 60 min of box-stepping exercise.
Compared to the placebo group no significant changes in MVC were observed immediately post-exercise, though recovery of MVC in the first 24 h post-exercise was greater in the group supplemented with vitamin C. The decrease in 20/50 Hz ratio of tetanic tension was significantly less (P < 0.05) post-exercise and in the initial phase of recovery in subjects supplemented with vitamin C but not with vitamin E. These data suggest that prior vitamin C supplementation may exert a protective effect against eccentric exercise-induced muscle damage (A528).
| VITAMIN C AND THE IMMUNE SYSTEM A)Vitamin C only B)Positive synergistic actions between vit C + other antioxidants A combination of vitamin C + E seems to:
1)Improve immune function in aged women.
2)Inhibit lipoperoxidation (2 studies).
3)Have some preventive effect on an experimental influenza virus infection in mice. A combination of vitamin C + phytoestrogens seems to:
Show stronger antioxidant activity on LDL oxidation in vitro (2 studies). A combination of vitamin C + citrus extract seems to:
Increase the lag time of lipoprotein oxidation in vitro and in vivo. A combination of vitamin C + 17 beta-estradiol seems to:
Inhibit LDL oxidation. A combination of vitamin C, E, beta carotene and penicillin seems to:
Decrease immunological abnormalities more effectively. C)Negative synergistic effects Adding vitamin E to vitamine C seems to:
Show an adverse effect on respiratory tract infections in elderly. Vitamin C seems to:
Be able to reduce the action of some medicines.
A)Vitamin C only: Citaat: Relation of serum ascorbic acid to Helicobacter pylori serology in US adults: the Third National Health and Nutrition Examination Survey.
Among whites, a 0.50 mg/dL increase in serum ascorbic acid level was associated with decreased seroprevalence of H. pylori (Odds Ratio (OR) = 0.89, 95% confidence interval (CI) CI 0.82-0.96, p < 0.01). In analyses that controlled for seroprevalence of H. pylori, a 0.50 mg/dL increase in serum ascorbic acid level among whites was independently associated with a decreased seroprevalence of the pathogenic cagA-positive strain of H. pylori (OR = 0.31, 95% CI 0.12-0.79, p < 0.05).
Higher serum levels of ascorbic acid were associated with a decreased seroprevalence of H. pylori and of the pathogenic cagA-positive strain of H. pylori among whites (A315).
| Citaat: Correlation between Helicobacter pylori infection and vitamin C levels in whole blood, plasma, and gastric juice, and the pH of gastric juice in Korean children.
During a 5-year period, multiple gastric antral biopsies were taken from 452 children who underwent gastroduodenoscopy.
Vitamin C levels in whole blood, plasma, and gastric juice exhibited significant negative correlation with the age of patients, the histologic density of H. pylori, the degree of active and chronic gastritis, and the severity of H. pylori infection (A316).
| B)Positive synergistic actions between vit C + other antioxidants: Citaat: Immune function in aged women is improved by ingestion of vitamins C and E.
30 women (10 healthy, 10 with major depression disorders, and 10 with coronary heart disease were administered 1 g vit C and 200 mg vit E/day for 16 weeks.
Intake of vitamins resulted in a significant increase in the lymphoproliferative capacity and in the phagocytic functions of PMN neutrophils as well as in a significant decrease of serum levels of lipid peroxides and cortisol, both in the healthy aged women and in the aged women with MDD or CHD. These findings suggest an important role of antioxidant supplementation in the improvement of immune function in aged females as well as in the prevention and treatment of specific diseases associated with age that are quite prevalent in the developed countries (A301).
| Citaat: Inhibitory capacity of human serum on induced microsomal lipoperoxidation.
Ten volunteers were supplemented with 400 mg of vitamin E and 1 g of vitamin C/daily for 2 weeks. Their serum inhibitory capacity increased in 12% (p < 0.05). The serum inhibitory capacity for microsomal lipoperoxidation is described herein, and we propose its utilization as an index to determine the individual nonspecific antioxidative defenses against free radical injury and lipoperoxidation in relation to exposure to air pollutants, tobacco smoke, and several acute and chronic diseases, including the hypoxia-reperfusion phenomena (A309).
| Citaat: [Experimental and clinical assessment of antioxidant efficacy of multicomponent antioxidant medication]
The study was made of kinetic parameters of copper-initiated free radical oxidation (FRO) of low density lipoproteins (HDLP) in human blood plasm, antioxidant potential of rat liver and myocardium, the level of FRO products in HDLP and activity of glutathione peroxidase in erythrocytes of 31 males aged 40-64 years with coronary heart disease (CHD).
An antioxidant action of the combinations alpha-tocopherol+ascorbic acid and alpha-tocopherol+beta-carotin was much more potent than that of each of the component alone.
A complex of antioxidant vitamins and selenium given to CHD patients for 2 months, sharply reduced the amount of FRO primary and secondary products in blood plasm LDLP in growing activity of erythrocytic selenium-containing glutathione peroxidase (A310).
| Citaat: Effect of vitamin E and vitamin C combination on experimental influenza virus infection.
Male mice (ICR), infected with influenza virus A/2/68/(H3N2) (1.5 of LD(50)), were administered single once-daily doses of vitamin E (60 mg/kg b.w.) and vitamin C (80 mg/kg b.w.) intraperitoneally (3 days before virus inoculation).
The preventive effect of vitamin E was stronger than the effect of vitamin C, but the combination (vitamin E + C) had the strongest effect. The superior protective effect of the combination is probably due to vitamin C's repairing effect on vitamin E's tocopheroxyl radical (A318).
| Citaat: Soy and alfalfa phytoestrogen extracts become potent low-density lipoprotein antioxidants in the presence of acerola cherry extract.
Copper-mediated LDL oxidation was inhibited in the presence of soy and alfalfa extracts, and this effect was further enhanced in the presence of acerola cherry extract, which is rich in ascorbic acid. Male rabbit aortic endothelial cells pretreated with soy extract were resistant to the toxic effects of high levels of LDL and LDL(-), and a lesser, but significant protection, was also afforded by alfalfa extract. Cell-mediated oxidation of LDL, measured by LDL(-) formation, was inhibited in the presence of soy extract but not alfalfa extract. However, in the presence of acerola cherry extract, both soy and alfalfa extracts potently inhibited the formation of LDL(-). These findings show that acerola cherry extract can enhance the antioxidant activity of soy and alfalfa extracts in a variety of LDL oxidation systems. The protective effect of these extracts is attributed to the presence of flavonoids in soy and alfalfa extracts and ascorbic acid in acerola cherry extract, which may act synergistically as antioxidants (A305).
| Citaat: Synergistic inhibition of LDL oxidation by phytoestrogens and ascorbic acid.
Increasing levels of genistein, daidzein, and equol inhibited LDL oxidation, and this inhibitory effect was further enhanced in the presence of ascorbic acid. The synergism exhibited by these compounds is of clinical importance to phytoestrogen therapy since the efficacy of phytoestrogens as effective antioxidants is evident at concentration well within the range found in the plasma of subjects consuming soy products (A307).
| Citaat: In Vitro and In Vivo Lipoprotein Antioxidant Effect of a Citrus Extract and Ascorbic Acid on Normal and Hypercholesterolemic Human Subjects.
In a double-blind, placebo-controlled study with 26 normal and hypercholesterolemic subjects, the citrus extract and vitamin C, but not vitamin C or vitamin E alone, significantly lowered triglycerides. The combination of citrus extract and vitamin C increased the lag time of lipoprotein oxidation, compared with vitamin C alone or a placebo, and was a significantly better antioxidant than vitamin E. These results and other published studies are highly suggestive of in vitro and in vivo antioxidant synergism between citrus extract and vitamin C (A306).
| Citaat: Ascorbic acid enhances 17 beta-estradiol-mediated inhibition of oxidized low density lipoprotein formation.
The enhanced activity of E(2) in the presence of ascorbate indicates that the antioxidant and antiatherosclerosis activity of E(2) may occur at concentrations within the physiological range (A308).
| Citaat: Immunological response to antioxidant vitamin supplementation in rural Bangladeshi school children with group A streptococcal infection.
Treatment by antioxidant vitamins (beta carotene, alpha tocopherol and ascorbic acid) plus penicillin is more effective in decreasing immunological abnormalities in GABHS infected children then penicillin alone (A314).
| Citaat: Antioxidant activity of dietary fruits, vegetables, and commercial frozen fruit pulps.
Fruits, vegetables, and commercial frozen pulps (FP) consumed in the Brazilian diet were analyzed for antioxidant activities using two different methods, one that determines the inhibition of copper-induced peroxidation of liposome and another based on the inhibition of the co-oxidation of linoleic acid and beta-carotene.
Some samples showed pro-oxidant activity in the liposome system coincident with a low antioxidant activity in the beta-carotene system. There was no relationship between total phenolics content, vitamin C, and antioxidant activity, suggesting that the antioxidant activity is a result of a combination of different compounds having synergic and antagonistic effects (A311).
| Citaat: Treatment of chronic hepatitis C virus infection via antioxidants: results of a phase I clinical trial]
Fifty chronic HCV patients were treated orally on a daily basis for 20 weeks with seven antioxidative oral preparations (glycyrrhizin, schisandra, silymarin, ascorbic acid, lipoic acid, L-glutathione, and alpha-tocopherol), along with four different intravenous preparations (glycyrrhizin, ascorbic acid, L-glutathione, B-complex) twice weekly for the first 10 weeks, and followed up for an additional 20 weeks.
A combination of antioxidants induced a favorable response in 48% of the patients (24). Normalization of liver enzymes occurred in 44% of patients who had elevated pretreatment ALT levels (15 of 34). ALT levels remained normal throughout follow-up period in 72.7% (8 of 11). A decrease in viral load (one log or more) was observed in 25% of the patients (12). Histologic improvement (2-point reduction in the HAI score) was noted in 36.1% of the patients. The SF-36 score improved in 26 of 45 patients throughout the course of the trial (58% of the patients). Treatment was well tolerated by all patients. No major adverse reactions were noted (A312).
| Citaat: Antioxidant vitamins improves hemoglobin level in children with group a beta hemolytic streptococcal infection.
Hemoglobin level increases after antioxidant vitamin supplementation (8 weeks) in 606 children suffering from group A beta hemolytic streptococcal infection (A317).
| C)Negative synergistic effect: Citaat: Vitamin C and E supplements to lansoprazole-amoxicillin-metronidazole triple therapy may reduce the eradication rate of metronidazole-susceptible Helicobacter pylori infection.
Adding vitamin C and E (250 mg + 200 mg, 2x/day) to triple therapy (lansoprazole, amoxicillin, metronidazole) cannot improve the H. pylori eradication rate and gastric inflammation. For patients with metronidazole susceptible strain infection, adding these vitamins may even reduce the eradication rate of triple therapy (A319).
| Citaat: Effect of daily vitamin E and multivitamin-mineral supplementation on acute respiratory tract infections in elderly persons: a randomized controlled trial.
Neither daily multivitamin-mineral supplementation at physiological dose nor 200 mg of vitamin E showed a favorable effect on incidence and severity of acute respiratory tract infections in well-nourished noninstitutionalized elderly individuals. Instead we observed adverse effects of vitamin E on illness severity (A320).
| VITAMIN C AND THE LIVER A)Vitamin C only
4 Studies showing a positive effect of vit C during liver stress. B)Vitamin C + E
3 Studies showing a positive effect from combined vit C + E on liver stress. B)Vitamin C + other antioxidants
3 Studies showing a positive effect from various antioxidants on the liver.
2 Studies showing no (positive nor negative) effect from mixed antioxidants on the liver.
A)Vitamin C only: Citaat: Vasoconstrictor hyporeactivity can be reversed by antioxidants in patients with advanced alcoholic cirrhosis of the liver and ascites.
Nine patients with liver cirrhosis Child-Pugh grade C and nine healthy age-matched volunteers.
In patients with cirrhosis, the reactivity to norepinephrine and angiotensin II was markedly reduced (p < .05 vs. controls). Coadministration of vitamin C completely restored the potency of vasoconstrictors to that in controls but had no effect in healthy subjects (A401).
| Citaat: Estimation of the functional reserve of the human liver by urinary D-glucaric acid excretion after vitamin C administration.
The excretion of D-glucaric acid in the urine (uGA) correlates with the total liver content of hepatic cytochrome P-450, the metabolism of which depends on adenosine triphosphate (ATP) being produced by intrahepatic cellular mitochondria. Five cases of compensated liver cirrhosis group with less than 0.4 mg/kg/min of the maximum removal rate of indocyanine green (ICGR max), and 5 cases with normal hepatic function (control group), were monitored for uGA before and after P-450 activation induced by administration of 1 g of vitamin-C. Before vitamin-C administration, no differences in uGA excretion were observed comparing the cirrhosis with the control group. After administration of vitamin-C, the excretion of uGA was significantly lower in the cirrhosis group. The measurement of uGA is considered to represent vitamin-C induced activation by P-450, and is a new method for evaluation of the functional reserve of the liver (A414).
| Citaat: Antioxidant levels in peripheral blood, disease activity and fibrotic stage in chronic hepatitis C.
Glutathione was an independent negative predictor of portal/periportal inflammation (P = 0.02) and fibrosis (P = 0.01). Vitamin C was an independent negative predictor of fibrosis stage (P = 0.02). Antioxidant intake was associated with higher vitamin C (P < 0.0001) and vitamin E (P = 0.005) levels, but not glutathione.
Whole blood glutathione and plasma vitamin C are negatively associated with hepatic portal/periportal inflammation and fibrosis stage in chronic hepatitis C (A402).
| Citaat: Supplementation of antioxidants prevents oxidative stress during a deep saturation dive.
A deep saturation dive (400 msw) decreases cholesterase activity, being highly suggestive of liver dysfunction.
600 mg of vitamin C, 150 mg of alpha-tocopherol, and 600 mg of tea catechins per day appeared to prevent a hepatic disturbance (A403).
| B)Vitamin C + E Citaat: Vitamin E and vitamin C treatment improves fibrosis in patients with nonalcoholic steatohepatitis.
1000 iu vit E + 1000 mg vit C/day for 6 months in 45 patients with nonalcoholic steatohepatitis did not show any significant side effects.
Vitamin treatment resulted in a statistically significant improvement in fibrosis score (p=0.002). No changes were noted in inflammation with treatment (A405).
| Citaat: Antioxidant capacity in Fasciola hepatica patients before and after treatment with triclabendazole alone or in combination with ascorbic acid (vitamin C) and tocofersolan (vitamin E).
Vitamin C (1000 mg/day) and vitamin E (600 mg/day) for 2 months in fasciola hepatica patients significantly improves of SOD and GPX activities and in lipid peroxide levels triclabendazole treatment(A408).
| Citaat: [Antioxidants in the treatment of cholelithiasis patients]
Complex administration of ascorbic acid and alpha-tocopherol was shown to improve the liver function in 157 patients operated upon for cholelithiasis (A411).
| C)(Vitamin C +) other antioxidants: Citaat: [Antioxidants in liver protection]
Combined antioxidant treatment is more favourable compared with monotherapy, because antioxidants have scavenger-, compartment- and tissue-specificity and they regenerate each other directly, too. Beside their antioxidant property they may also directly regulate many important processes, e.g. cell cycle. We have some favourable results with regard combined antioxidant therapy of liver disease of different etiology (A404).
| Citaat: Relation of elevated serum alanine aminotransferase activity with iron and antioxidant levels in the United States.
We analyzed the associations of serum iron measures and antioxidant concentrations with abnormal serum alanine transaminase (ALT) activity in a large, national, population-based study (13,605 adult participants). The risk for apparent liver injury was associated with increased iron and decreased antioxidants, particularly carotenoids (A406).
| Citaat: Oral antioxidant supplementation for fatigue associated with primary biliary cirrhosis: results of a multicentre, randomized, placebo-controlled, cross-over trial.
We have previously reported, in an uncontrolled trial, an improvement in fatigue scores in patients with primary biliary cirrhosis given oral antioxidant supplementation. We now present data from a controlled trial.
Antioxidant supplementation (vitamins A, C and E, selenium, methionine and ubiquinone) for 12 weeks in 61 patients with primary biliary cirrhosis-associated fatigue does not show any significant changes in fatigue. Neither medication was associated with improvement in any other symptoms related to primary biliary cirrhosis. Adverse effects were more common during active therapy and were mild and self-limiting (A407).
| Citaat: [The role of alpha-tocopherol and retinol in correcting disorders of lipid peroxidation in patients with malignant liver neoplasms]
Treatment with alpha-tocoferol (600 mg), retinol (100,000 MU) and ascorbic acid (1.5 g) for 7 days before surgery was found to significantly reduce dialdehyde level in the liver. Also, the catalase level increased. Treatment with alpha-tocoferol and retinol resulted in their selective accumulation in the liver. No changes in lipid peroxidation or accumulation of alpha-tocoferol in tumor were recorded. Purulent and septic complications were 1.6 times less frequent after preoperative antioxidant treatment than in controls. It is recommended that said antioxidant treatment should be used to correct lipid peroxidation and to improve the effectiveness of therapy of liver cancer (A412).
| Citaat: The effect of antioxidant supplementation on a serum marker of free radical activity and abnormal serum biochemistry in alcoholic patients admitted for detoxification.
Alcoholics admitted for detoxification were entered into a double blind placebo controlled trial of oral supplementation with an antioxidant cocktail (vitamin E, beta carotene, vitamin C and selenium). There was no effect of this supplementation on the rate of resolution of a serum marker of free radical activity and abnormal serum biochemistry (A413).
| |
9 November 2005, 08:15
