Effect of vitamin C administration in modulating some biochemical changes in arthritic rats

Effect of green tea extract and vitamin C on oxidant or antioxidant status of rheumatoid arthritis rat model

Elevated free radical generation in inflamed joints and impaired antioxidant system has been implicated in rheumatoid arthritis (RA). Green tea extracts (GTE) have been shown to reduce inflammation in inflammatory arthritis murine model. This study investigates possible mechanisms by which vitamin C and GTE protect joints in RA rat model. This study included forty adult male rats that were divided into four groups (10 rats each); control group, collagen II induced RA group (CII), CII treated with vitamin C (CII + Vit C) and CII treated with GTE (CII + GTE) in physiology laboratory, Assiut University, Egypt. After 45 days of treatment, plasma levels of lipid peroxides (LPO), nitric oxide (NO), ceruloplasmin (CP), superoxide dismutase (SOD), uric acid (UA) and glutathione (GSH) were detected using colorimetric methods, PGE(2) using ELISA and copper (Cu) and zinc (Zn) using spectrometer. In CII group, levels of LPO, NO, PGE(2), UA, CP, Cu were higher while SOD, GSH, Zn were lower than controls. In groups treated with vitamin C and GTE, levels of SOD, GSH were increased while levels of LPO, NO, PGE(2), Cu, CP were decreased compared with CII group. Levels of UA were decreased and Zn increased in GTE treated group compared with CII group. GTE treated group showed higher Zn and low Cu levels compared with vitamin C treated group. This study suggests proper GTE and vitamin C intake may effectively normalize the impaired oxidant/antioxidant system and delaying complication of RA.

Enhanced intraarticular free radical reactions in adjuvant arthritis rats

One of the reasons of rheumatoid arthritis (RA) development is widely recognized the relation of free radical reactions in tissue injuries. The aim of this study was to evaluate the location where in vivo free radical reactions was enhanced in adjuvant arthritis (AA) model rats using in vivo electron spin resonance (ESR)/nitroxyl spin probe technique. The signal decay after intravenous injection of spin probe was enhanced in AA than that in control and suppressed by the pre-treatment of dexamethasone (DXT). Interestingly, the decay in joint cavity occurred prior to paw swelling of AA and suppressed by a simultaneous injection of free radical scavengers, indicating that the enhancement of free radical reactions in joint cavity of AA rats. This technique would be useful tool to determine the location of the enhanced free radical reactions and evaluate the activity of antioxidant medicine with non-invasive real-time measurement.

Developments in the rat adjuvant arthritis model and its use in therapeutic evaluation of novel non-invasive treatment by SOD in Transfersomes

The aim of this study was firstly to refine a rat model of arthritis, the adjuvant arthritis (AA) model, by studying the time course of the disease, introducing new evaluation methods such as haematological and biochemical parameters in order to identify the main stages of the disease. An optimisation of treatment schedule and evaluation criteria was developed. This refinement provided novel non-invasive anti-inflammatory treatment of the AA with SOD by using mixed lipid vesicles specially developed for transdermal delivery, Transfersomes (Tfs), this being the second major aim. The time course of AA includes a first stage: 1 day after the disease induction, the induced paw volume more than doubled and the paw circumference increased by approx. 50%. Two weeks later, another stage occurred where the disease shifted from the local arthritis form towards polyarthritis: an additional increase of volume and circumference of the induced and non-induced paws, occurred. The animals also started to loose weight around day 14 after the disease induction. Radiographic observable lesions increased correspondingly. Treatment of animals, started at day 1 after induction, by epicutaneous application of SOD-Tfs showed that 1 mg SOD/kg body weight is more efficient than 0.66 mg SOD /kg body weight. As a positive control, SOD liposomes intravenously injected were used for comparison and confirmed the biological efficiency of epicutaneously applied SOD in Tfs. SOD solution and empty Tfs epicutaneously applied exerted no effect. In addition, epicutaneous application of SOD-Tfs used prophylactically was able to suppress the induced rat paw oedema. Radiographic images showed less joint lesions in SOD-Tfs treated animals in comparison with control and placebo treated rats. It was shown for the first time that SOD incorporated into Tfs and applied onto a skin area not necessarily close to the inflamed tissue is able to promote non-invasive treatment of induced arthritis.

Effect of type II collagen treatment on the antioxidant status in immune tissues of adjuvant induced arthritic rats

Adjuvant induced arthritis (AIA) is a model widely used to study Rheumatoid arthritis (RA). In the present study, lipid peroxides level in spleen and thymus of AIA rats was observed to be significantly high compared to normal rats. A significant decrease in ascorbic acid (ASA), reduced glutathione (GSH), superoxide dismutase activity (SOD) was also observed in spleen and thymus of AIA rats compared to normal rats. There was also a steady increase in the circulating immune complex level (CIC) throughout the experimental period in serum of AIA rats. In the present investigation, it was decided to study the effect of pre and post treatment with TYPE II collagen on the antioxidant status and the circulating immune complex level in AIA rats. The results from the present work indicates that the pretreatment with TYPE II collagen was effective in bringing significant changes on all the parameters studied in AIA rats. The post treatment with TYPE II collagen was effective in bringing significant changes on the CIC immune complex level and GSH content in the thymus tissue of AIA rats. The present work suggests that the pre treatment with TYPE II collagen was more effective in suppressing the disease than the post treatment.

Nutritional management of rheumatoid arthritis: a review of the evidence

Rheumatoid arthritis (RA) is a debilitating disease and is associated with increased risk of cardiovascular disease and osteoporosis. Poor nutrient status in RA patients has been reported and some drug therapies, such as nonsteroidal anti-inflammatory drugs (NSAIDs), prescribed to alleviate RA symptoms, may increase the requirement for some nutrients and reduce their absorption. This paper reviews the scientific evidence for the role of diet and nutrient supplementation in the management of RA, by alleviating symptoms, decreasing progression of the disease or by reducing the reliance on, or combating the side-effects of, NSAIDs. Supplementation with long-chain n-3 polyunsaturated fatty acids (PUFA) consistently demonstrates an improvement in symptoms and a reduction in NSAID usage. Evidence relating to other fatty acids, antioxidants, zinc, iron, folate, other B vitamins, calcium, vitamin D and fluoride are also considered. The present evidence suggests that RA patients should consume a balanced diet rich in long-chain n-3 PUFA and antioxidants. More randomized long-term studies are needed to provide evidence for the benefits of specific nutritional supplementation and to determine optimum intake, particularly for n-3 PUFA and antioxidants.

Biochemical changes in arthritic rats: dehydroascorbic and ascorbic acid levels

The objective of this work was to evaluate the use of vitamin C as a biomarker in the inflammatory phase of the rat adjuvant arthritis and to correlate it with other parameters used for disease evaluation. Paw swelling was used for physical evaluation and the levels of ascorbate and dehydroascorbate in the serum of male rats, before and after adjuvant arthritis induction, were quantified by a high-performance liquid chromatography method (HPLC). The optimised HPLC assay enabled the quantification of both forms of the vitamin in rat sera, with the same extraction method and using different detectors, instead of obtaining dehydroascorbate by subtraction of the total ascorbate measurement. This method was used to follow the severity of adjuvant arthritis and the results were correlated with other already established disease activity parameters. A decrease of ascorbic acid and dehydroascorbic acid was observed with the increase of right paw circumference during the course of adjuvant arthritis. The disease associated changes in the serum concentrations of ascorbic acid, from biosynthesis and from recycling, can be evaluated by the direct quantification of dehydroascorbic acid. This provides some evidence for the potential of the quantification of these biomarkers to study the disease activity, and as a tool for the establishment of therapeutic protocols, to evaluate the anti-inflammatory effect of new drugs or formulations.