Purpose of investigation: Serum paraoxonase (PON 1) is one of the most important enzymatic antioxidants that hydrolyzes lipid peroxidation, an indicator of carcinogenic activity. The aim of this study was to compare the serum levels of paraoxonase and arylesterase activity in patients with endometrial cancer to those of healthy controls. Methods: Serum paraoxonase and arylesterase activities, total free sulphydryl (-SH) groups and lipid hydroperoxide (LOOH) levels were measured in patients with endometrial cancer (n = 20) and controls (n = 23). Results: Serum paraoxonase, arylesterase activities and total -SH group levels were significantly lower in patients compared to controls (p < 0.05, p < 0.05 and p < 0.001; respectively), while LOOH levels were significantly higher (p < 0.001). Among patients, serum paraoxonase and arylesterase activities were inversely correlated with LOOH levels (r = -0.680, p < 0.05; r = -0.708, p < 0.001; respectively), while these were positively correlated with the total -SH group (r = 0.526, p < 0.05; r = 0.508, p < 0.05; respectively). Conclusion: Reduced serum PON 1 activity might contribute to an impaired antioxidant defense system which plays a critical role in carcinogenesis in patients with endometrial cancer.</p
