The assessment of total antioxidant capacity and superoxide dismutase levels, and the possible role of manganese superoxide dismutase polymorphism in acromegaly.

Oxidative status is attributed to endothelial dysfunction and might be one of the key mechanisms of endothelial dysfunction in acromegaly. In this study, we aimed to investigate the effect of acromegaly on superoxide dismutase (SOD) and total antioxidant capacity (TAC) levels, and the possible influence of human manganese superoxide dismutase (MnSOD) polymorphism on these levels. 51 acromegaly patients and 57 age and sex matched healthy subjects were recruited to the study in Bezmialem Vakif University Hospital between 2011 and 2014. The median SOD and TAC levels were 42.7 (33-60) pg/mL and 1,313.7 (155-1,902) µM in acromegaly; and 46.3 (38-95) pg/mL and 1,607.3 (195-1,981) µM in healthy subjects (p < 0.001, p < 0.001). SOD levels were decreased in controlled and uncontrolled patients compared to healthy subjects (p = 0.05 and p = 0.002, respectively). Controlled and uncontrolled acromegaly displayed significantly decreased levels of TAC compared to healthy subjects (p < 0.05 and p < 0.001, respectively). SOD levels were not associated with MnSOD polymorphisms in acromegaly. In conclusion, this study showed that acromegaly was associated with decreased levels of SOD and TAC, and controlling the disease activity could not adequately improve these levels.

Individual and Combined Effects of CTLA4-CD28 Variants and Oxidant-Antioxidant Status on the Development of Colorectal Cancer.

BACKGROUND: Colorectal cancer (CRC) is the third most frequent cancer worldwide. Research has revealed the contributions of the immune system and anti-inflammatory pathways in the development of cancer. The balance between cluster of differentiation 28 (CD28) and cytotoxic T-lymphocyte-associated protein 4 (CTLA4) signaling is important for the regulation of immune responses. The oxidant-antioxidant balance by sustaining redox control via several defense mechanisms is also an important factor for the progression of cancer. The aim of the present study was to determine the distribution of CTLA4/CD28 variants and oxidant-antioxidant status in patients with CRC. MATERIALS AND METHODS: This study enrolled 80 patients with CRC and 115 healthy controls. We used a spectrophotometric assay to detect the levels of lipid peroxidation products malon dialdehyde (MDA) and lipid hydroperoxide (LHP), and measured the concentration of protein damage products, advanced oxidation protein products (AOPP) and protein carbonyl (PCO). Additionally, antioxidant levels were detected by measuring copper, zinc, superoxide dismutase (Zn-Cu SOD) and total thiol (T-SH) levels, and advanced glycation end-products (AGEs). The CTLA4 -318C>T, CTLA4 49A>G and CD28C>T genotypes were determined by using restriction enzymes. RESULTS: AOPP and PCO levels were increased in patients with CRC as well as those of LHP, MDA and AGE, while the levels of antioxidants such as Cu-Zn SOD and T-SH were lower. Lower serum levels of CTLA4 and higher serum levels of CD28 were detected in patients and, an association of the CTLA4 -318C/T polymorphism was found in patients with CRC. CONCLUSION: Our oxidative stress was increased in patients with CRC, suggesting the contribution of this disturbed oxidative status to serum CTLA4 and CD28 levels, and to the pathogenesis of CRC.