A new marker for lipid peroxidation: serum paraoxonase activity in non-alcoholic steatohepatitis.

BACKGROUND/AIMS Relationship between hepatic antioxidant paraoxonase 1 (PON1) activity, lipid peroxidation and liver injury was investigated in patients with non-alcoholic steatohepatitis. METHODS A total of 23 patients with non-alcoholic steatohepatitis (15 males, 8 females; mean age: 40.30+/-7.67 yrs) and 23 healthy controls (14 males, 9 females; mean age: 39.70+/- 8.78 yrs) were enrolled in the study. Serum paraoxonase 1 activity and levels of a well-known lipid peroxidation marker, serum malondialdehyde, were determined. RESULTS Serum paraoxonase 1 activity decreased significantly in non-alcoholic steatohepatitis compared to the control group (p<0.01). Serum malondialdehyde levels were significantly higher in patients with non-alcoholic steatohepatitis as compared with the control group (p<0.05). No statistically significant correlations were found between serum paraoxonase 1 activities and the grade-stage of non-alcoholic steatohepatitis, serum lipid levels or serum malondialdehyde levels (p>0.05). CONCLUSIONS Increased lipid peroxidation may be either a cause or a result of liver injury in patients with non-alcoholic steatohepatitis. Although serum paraoxonase 1 activity does not reflect the degree of liver damage in non-alcoholic steatohepatitis, reduced paraoxonase 1 activity, especially in the presence of mild disease, could be interpreted as a biochemical marker of the lipid peroxidation.