DNA damage and its relationship with other oxidative stress parameters in Behcet's disease.

Behçet's disease (BD) is a multisystemic, chronic inflammatory, relapsing disorder that is characterized by oral/genital ulcerations, ocular, arthritic, vascular, and neurologic involvements. Recent findings suggest the role of increased oxidative stress and insufficient antioxidant defence system in BD pathogenesis. It has been proposed that the increase in phagocytic cell activity by triggering oxidative reactions in various targets such as lipids, proteins, and DNA leads to severe inflammatory and degenerative pathologies seen in BD In this study, oxidant/antioxidant status of patients with BD was evaluated in comparison with controls and in respect to disease activity by measuring serum nitrite/nitrate, vitamin A, malondialdehyde (MDA), 8-hydroxy deoxyguanosine (8-OHdG), and total sulfhydryl levels (T-SH). The increase in serum MDA and 8-OHdG levels (respectively 30.04 vs. 17.93 nmol/ml, P = 0.0004 and 1.60 vs. 1.03 ng/ml, P = 0.0019) and the decrease in T-SH levels of patients with BD in comparison with controls (0.69 vs. 0.76 mmol/l, P = 0.0085) all indicate the impaired oxidant/antioxidant status in BD. The positive correlation found between MDA/8-OHdG levels (P = 0.02), and the negative correlations both between T-SH/8-OHdG levels (P = 0.031) and T-SH/MDA levels (P = 0.009) show the concordance between the parameters evaluating oxidant-antioxidant status. Among the parameters used for evaluating oxidant/antioxidant status, serum 8-OHdG was the only one showing significantly higher levels in patients with clinically active disease in comparison (P = 0.004) to patients in inactive period. Therefore, 8-OHdG that is assessed for the fist time in BD with this study can be proposed as a more reliable indicator of oxidant stress in evaluating disease activity.

The effect of l-deprenyl on tissue mRNA expressions of NOS isoforms and NO levels in an experimental diabetes mellitus model.

Diabetes and aging share some common mechanisms in their pathogenesis and diabetics are more prone to diseases of the elderly. Seeking for therapies likely to be proposed in the synchronised treatment of aging and diabetes is of great interest and l-deprenyl, a selective monoamine oxidase (MAO-B) inhibitor, is a possible candidate with its antioxidant, antiapoptotic and neuroprotective properties. Tissue MAO, NO and mRNA expression of nitric oxide (NO) synthase (NOS) isoforms were assessed in streptozotocin (STZ)-induced diabetic rats to evaluate the effect of l-deprenyl treatment. Twelve weeks of treatment had no significant effect on NO levels. Four-weeks treatment decreased tissue MAO activities and caused a decrease in expression of NOS-2 and NOS-3 in heart tissue of both controls and diabetics, and a decrease of liver NOS-3 expression in controls (p < 0.05). l-Deprenyl, causing a decrease in tissue NOS expressions, might be of benefit by protecting the organism from the toxic radical effects of NO.