Search

Purpose: Chronic renal failure patients undergoing peritoneal dialysis (PD) are characterized by increased oxidative stress (OS), which is associated with enhanced cardiovascular risk. Moreover, oxidative stress also contributes to peritoneal membrane changes and ultrafiltration failure. The aim of this study was to evaluate OS in PD patients and the effect of treatment with ascorbic acid and α-tocopherol., Methods: Plasma, erythrocyte, urine, and peritoneal effluent samples from 20 patients on PD were evaluated for glutathione peroxidase and superoxide dismutase activity, total antioxidant capacity (TAC) and malondialdehyde (MDA) levels, as well as protein carbonyl formation, before and after administration of vitamin C, alone or in combination with vitamin E, in comparison with 10 apparently healthy control individuals., Results: All studied markers showed enhanced OS in the PD group, compared to controls. The supplementation of vitamin C and E resulted in improvements of all the OS markers, as indicated by increased erythrocyte antioxidant enzymes activity and TAC levels, as well as decreased MDA concentration and carbonyl compound formation., Conclusions: The oral supplementation of antioxidant vitamins C and E, in combination, can lead to decreased OS, thus providing a useful and cost-effective therapeutic option in PD patients.

Platelets aggregation around migrating tumor cells offers protection against the cytotoxic activity of the natural killers cells (NKC). The ascorbic acid in 3 x 10(-3) M concentration completely inhibited platelet aggregation, decreased thromboxane B2 levels, and inhibited the expression of platelet membranic receptor GpIIb/IIIa in non stimulated platelets, and increased the NKC cytotoxicity in an average rate of 105, 61, and 285% in the NKC/targets cells ratios 12.5:1, 25:1 and 50:1 respectively. The results suggest the role of ascorbic acid in increasing the susceptibility of tumor cells to NKC; the ascorbic acid could be used as part of a multidrug therapy to treat diseases which up to now have been treated only through chemotherapy.

Objectives: To investigate the effectiveness of vitamin C and E supplementation in remission of the symptoms of chronic degenerative arthritis (osteoarthritis) of the knee. Design: A pilot controlled trial conducted from December 2009 until April 2011 among 46 patients diagnosed with osteoarthritis (OA) in one or both knees. Intervention: Patients were randomly assigned to two different treatment groups and were either supplemented with ascorbic acid 1 gr x 2 daily per os together with vitamin E 100 mg x 3 daily per os or they were treated with meloxicam tabs 15 mg x 1 daily per os. Main outcome measures: A. Clinical markers: functionality of the knee (WOMAC index), pain (using a pain visual analogue scale) and the deficit in knee flexion and extension B. Laboratory markers: total antioxidant capacity (TAC) and concentration of malonyldialdehyde (MDA) in the synovial fluid. Results: Twenty patients were randomly allocated into each of the two intervention groups. The treatment lasted for 20 days and the patients' status was evaluated every 10 days. The condition of the patients' knees in both treatment groups presented a significant improvement as recorded by the clinical markers; accompanied by an enhancement of TAC but with no effect on MDA levels. Conclusions: Administration of vitamins C and E has a similar effect in the remission of the symptoms of the OA in the knee, comparable to that of the treatment with meloxicam, but without the possible side effects and thus can be proposed as adjuvant therapy. [ABSTRACT FROM AUTHOR]