Role of oxidative stress in various stages of psoriasis.

Psoriasis is a chronic inflammatory, proliferative skin disease characterized by pathological skin lesions due to various exogenous and endogenous factors. It is associated with a number of biochemical and immunological disturbances. Recently, it has been suggested that increased reactive oxygen species (ROS) production and compromised function of antioxidant system may be involved in the pathogenesis of this disease. In the present study, 90 psoriasis patients were selected. Disease severity was assessed by psoriasis area severity index score and grouped as mild, moderate and severe (each group consists of 30 subjects) and compared with 30 healthy controls. Serum levels of malondialdehyde, nitric oxide end products and the activities of antioxidant enzymes such as erythrocyte-superoxide dismutase, catalase and total antioxidant status were investigated in these groups/subjects. As compared to controls, we found severitywise significantly increased serum malondialdehyde, nitric oxide end products with decrease in erythrocyte-superoxide dismutase activity, catalase activity and total antioxidant status in patients with psoriasis suggesting worsening of the disease. It seems to be linked with the enhancement of Reactive Oxygen Species production and decreased antioxidant potential in psoriasis.

Depleted nitrite and enhanced oxidative stress in urolithiasis.

Crystal aggregation and retention are critical events for the formation of kidney stones. There is a close association between crystal development and free radical activity in vivo. In the present study 30 subjects presenting with urolithiasis were included. Serum levels of total lipid peroxides, nitric oxide (as nitrite), α-tocopherol, plasma ascorbic acid (vitamin C) and erythrocyte superoxide dismutase activity were measured. These findings were compared with 30 age matched control subjects irrespective of sex. Student's 't' test was applied for statistical analysis. There was a significant increase in lipid peroxides (p<0.001), where as significant decrease in nitrite (p<0.01) and α-tocopherol (p<0.001) levels were observed. Plasma ascorbate (p>0.05) and erythrocyte superoxide dismutase activity (p>0.05) was also found to be decreased but the difference was not statistically significant which suggests that oxidative stress is evident in urolithiasis with depletion in antioxidant status where as decrease in nitric oxide may be less abetting in disease condition.