Oxidative stress and antioxidant defenses in serum of patients with non-alcoholic steatohepatitis

Objectives: Oxidative stress is an important pathophysiological mechanism in non-alcoholic steatohepatitis (NASH). We aimed to evaluate serum xanthine oxidase (XO) (as a generator of reactive oxygen species), superoxide dismutase (SOD), glutathione peroxidase (GSHPx), paraoxonase (PON1) activities, nitric oxide (NO) and thiol levels in patients with NASH. Design and methods: A total of 35 patients with NASH and 31 age-and-gender-matched healthy subjects were enrolled in the study as control group. Serum levels of XO, NO, SOD, GSHPx, PON1 and thiol were determined by spectrophotometric methods. Results: Serum XO activities were higher in the patients with NASH than the controls (p < 0.001). Serum NO levels, SOD, GSHPx, PON1 activities and thiol levels were lower in the patients with NASH than the controls (p < 0.031, p < 0.019, p < 0.001, p < 0.001, p < 0.001, respectively). Conclusions: Increased oxidative stress in patients with NASH may result in a pro-oxidation environment, which in turn could result in decreased antioxidant enzyme activities and NO levels. Therefore effective antioxidant therapy to inhibit oxidative stress is necessary and agents to increase antioxidant enzyme may be a therapeutic option in NASH.