1.
Dose-dependent vitamin C uptake and radical scavenging activity in human skin measured with in vivo electron paramagnetic resonance spectroscopy.
Lauer, AC, Groth, N, Haag, SF, Darvin, ME, Lademann, J, Meinke, MC
Skin pharmacology and physiology. 2013;(3):147-54
Abstract
Vitamin C is a potent radical scavenger and a physiological part of the antioxidant system in human skin. The aim of this study was to measure changes in the radical-scavenging activity of human skin in vivo due to supplementation with different doses of vitamin C and at different time points. Therefore, 33 volunteers were supplemented with vitamin C or placebo for 4 weeks. The skin radical-scavenging activity was measured with electron paramagnetic resonance spectroscopy. After 4 weeks, the intake of 100 mg vitamin C/day resulted in a significant increase in the radical-scavenging activity by 22%. Intake of 180 mg/day even resulted in a significant increase of 37%. No changes were found in the placebo group. A part of the study population was additionally measured after 2 weeks: in this group radical scavenging had already reached maximal activity after 2 weeks. In conclusion, orally administered vitamin C increases the radical-scavenging activity of the skin. The effect occurs fast and is enhanced with higher doses of vitamin C.
2.
[Estimation of antioxidative effect of atorvastatin and fluvastatin used in primary prevention of coronary heart disease--effect on lipid peroxidation].
Kowalski, J, Pawlicki, L, Grycewicz, J, Błaszczyk, J, Irzmański, R, Cegliński, T, Kowalczyk, E, Liban-Gałka, B
Wiadomosci lekarskie (Warsaw, Poland : 1960). 2005;(7-8):386-90
Abstract
The study comprised 35 patients with mixed hyperlipidaemia and coronary heart disease (CHD) risk factors (overweight or obesity, low physical activity, family history). Seventeen patients were administered atorvastatin in a dose of 10 mg and 18 -fluvastatin in a dose of 40 mg once daily at bed time for 6 weeks. The control group consisted of 12 clinically healthy subjects with no CHD risk factors. Blood samples for testing were collected from cubital vein of patients after hypolipaemic diet prior to and 6 weeks after drugs application and once in control group. Malondialdehyde (MDA) concentrations in erythrocytes and plasma were determined by the method of Placer et al. MDA concentrations in erythrocytes and plasma were significantly higher (p < 0.05) in patients than in healthy subjects. After 6-week atorvastatin therapy MDA concentrations in erythrocytes and plasma decreased to the values observed in healthy subjects. In fluvastatin group erythrocyte and plasma MDA concentrations were unchanged and still significantly higher in comparison to the healthy subjects. Atorvastatin, contrary to fluvastatin, decreases lipid peroxidation in CHD risk patients.
3.
Effects of young barley leaf extract and antioxidative vitamins on LDL oxidation and free radical scavenging activities in type 2 diabetes.
Yu, YM, Chang, WC, Chang, CT, Hsieh, CL, Tsai, CE
Diabetes & metabolism. 2002;(2):107-14
Abstract
BACKGROUND The effects of supplementation of young barley leaf extract (BL) and/or antioxidative vitamins C and E on different low-density lipoprotein (LDL) subfractions susceptibility to oxidation and free radical scavenging activities in patients with type 2 diabetes were evaluated. METHODS Thirty-six type 2 diabetic patients were enrolled in this study. The subjects received one of the following supplements daily for 4 weeks: 15 g BL, 200 mg vitamin C and 200 mg vitamin E (CE), or BL plus CE (BL + CE). RESULTS The lucigenin-chemiluminescence (CL) and luminol-CL levels in blood were significantly reduced in all groups. Vitamin E content of LDL subfractions increased significantly following supplements, especially for BL + CE group. The percent increase of lag times in the BL + CE was significantly higher than those in the BL or CE group. The antioxidative effect of BL + CE was the greatest for small, dense LDL (Sd-LDL) with further increases in percentage of lag times 4 folds compared to BL alone. CONCLUSION Our results indicate that supplementation with BL may help to scavenge oxygen free radicals, save the LDL-vitamin E content, and inhibit LDL oxidation. Furthermore, the addition of vitamins C and E to BL can inhibit the Sd-LDL oxidation more effectively, which may protect against vascular diseases in type 2 diabetic patients.
4.
Influence of N-acetylcysteine on hepatic amino acid metabolism in patients undergoing orthotopic liver transplantation.
Taut, FJ, Breitkreutz, R, Zapletal, CM, Thies, JC, Babylon, A, Martin, E, Dröge, W
Transplant international : official journal of the European Society for Organ Transplantation. 2001;(5):329-33
Abstract
Experimental treatment with the antioxidant and glutathione precursor N-acetylcysteine (NAC) has been performed in orthotopic liver transplantation (OLT) to reduce reperfusion injury. To investigate the effect of NAC on the hepatic and intestinal amino acid metabolism, intraoperative amino acid exchange rates were studied in liver transplant recipients with high dose NAC treatment (n = 10) and in control patients (n = 9). Treatment with NAC was found to cause a loss of amino acids and increased urea nitrogen release from the liver graft. The net balance of most amino acids was shifted to increased hepatic release or decreased hepatic uptake. The initial cumulative splanchnic release of all proteinogenic amino acids in the NAC treated group was significantly higher than in the control group. These findings are tentatively explained by an increased net protein catabolism in the liver. The increased hepatic urea and glutamine production rate of the NAC treated patients is expected to increase the energy and oxygen demand of the liver in this critical situation. Thus, NAC may have caused marked metabolic disturbances in the freshly implanted graft. The dosage of NAC should therefore be modified to avoid these disadvantages.