Erythrocytes undergo various changes during storage (storage lesion) that in turn reduces their functioning and survival. Oxidative stress plays a major role in the storage lesion and antioxidants can be used to combat this stress. This study elucidates the effects of L-carnitine (LC) on erythrocytes of stored blood. Blood was obtained from male Wistar rats and stored (4°C) for 20 days in CPDA-1 (citrate phosphate dextrose adenine) solution. Samples were divided into-(i) controls (ii) LC 10 (L-carnitine at a concentration of 10 mM) (iii) LC 30 (L-carnitine at a concentration of 30 mM) and (iv) LC 60 (L-carnitine at a concentration of 60 mM). Every fifth day, the biomarkers (haemoglobin, hemolysis, antioxidant enzymes, lipid peroxidation and protein oxidation products) were analysed in erythrocytes. Hemoglobin and protein sulfhydryls were insignificant during storage indicative of the maintenance of hemoglobin and sulfhydryls in all groups. Superoxide dismutase and malondialdehyde levels increased initially and decreased towards the end of storage. The levels of catalase and glutathione peroxidase were lower in experimentals than controls during storage. L-carnitine assisted the enzymes by scavenging the reactive oxygen species produced. Hemolysis increased in all groups with storage, elucidating that L-carnitine could not completely protect lipids and proteins from oxidative stress. Hence, this study opens up new avenues of using L-carnitine as a component of storage solutions with combinations of antioxidants in order to maintain efficacy of erythrocytes.

There is a dire necessity to improve blood storage and prolong shelf-life of blood. Very few studies have focused on oxidative stress (OS) in blood and its influence on plasma with storage. This study attempts to (i) elucidate the continuous changes occurring in plasma during storage through oxidant levels and antioxidant status and (ii) evaluate the influence of vitamin C (VC) as an additive during blood storage. Blood was drawn from male Wistar rats and stored for 25 days at 4°C. Blood samples were divided into control and experimental groups. Plasma was isolated every 5 days and the OS markers, antioxidant enzymes, lipid peroxidation, and protein oxidation products, were studied. Catalase activity increased in all groups with storage. Lipid peroxidation decreased in VC (10) but was maintained in VC (30) and VC (60). Although there were variations in all groups, carbonyls were maintained towards the end of storage. Advanced oxidation protein products (AOPP) increased in VC (30) and were maintained in VC (10) and VC (60). Sulfhydryls were maintained in all groups. Vitamin C could not sufficiently attenuate OS and hence, this opens the possibilities for further studies on vitamin C in combination with other antioxidants, in storage solutions.

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The antioxidant defense in A, B, and O groups were similar as evident from our results of Hb, antioxidant enzymes and sulfhydryls. However, the response of blood group O diverged from that of A and B, substantiated by the results of MDA, AOPP, and superoxides. Thus blood group O endured oxidative insult more efficiently than A and B. This study forms the basis for future studies on erythrocyte membrane and exploring blood group O as a potential candidate for prolonging storage.

In this study of 41 patients, we used proteomic, Western blot and immunohistochemical analyses to show that several reactive oxygen species scavenging enzymes are expressed differentially in patients with primary osteoarthritis and those with non-loosening and aseptic loosening after total hip replacement (THR). The patients were grouped as A (n = 16, primary THR), B (n = 10, fixed THR but requiring revision for polyethylene wear) and C (n = 15, requiring revision due to aseptic loosening) to verify the involvement of the identified targets in aseptic loosening. When compared with Groups A and B, Group C patients exhibited significant up-regulation of transthyretin and superoxide dismutase 3, but down-regulation of glutathione peroxidase 2 in their hip synovial fluids. Also, higher levels of superoxide dismutase 2 and peroxiredoxin 2, but not superoxide dismutase 1, catalase and glutathione perioxidase 1, were consistently detected in the hip capsules of Group C patients. We propose that dysregulated reactive oxygen species-related enzymes may play an important role in the pathogenesis and progression of aseptic loosening after THR.