Serum paraoxonase-1 enzyme activities and oxidative stress levels in patients with esophageal squamous cell carcinoma.

OBJECTIVES

Oxidative stress is well recognized to play a role in the pathogenesis of many diseases, including cancers. Paraoxonase-1 (PON1) is implicated in the elimination of carcinogenic lipid-soluble radicals produced by lipid peroxidation. Reports on PON1 activities in patients with cancer are conflicting. The aim of this study was to investigate serum antioxidant enzyme activities and oxidative stress levels in patients with esophageal squamous cell carcinoma (ESCC).

PATIENTS AND METHODS

Thirty-two patients with ESCC and 33 healthy controls were enrolled. Serum malondialdehyde (MDA) levels and superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), glutathione reductase (GR), paraoxonase, and arylesterase activities were measured spectrophotometrically.

RESULTS

Serum paraoxonase, arylesterase, SOD, activities, GSH-Px, and GR activities were significantly lower in patients with ESCC than in controls (all, P < 0.05), whereas serum MDA levels were significantly higher (P < 0.05). Serum MDA levels were significantly correlated with paraoxonase (r = -0.572, P < 0.001) and arylesterase activities (r = -0.597, P < 0.001) in patients with ESCC.

CONCLUSIONS

This study indicated that ESCC is associated with increased oxidative stress and decreased antioxidant enzyme activities. Decreased serum PON1 enzyme activities may play a role in the progression and/or development of ESCC. Further studies are required to clarify these results.