Decreased serum paraoxonase and arylesterase activities in patients with rosacea

Recent evidence suggests that oxidative stress may be an important phenomenon in the pathophysiology of rosacea. Paraoxonase-1 (PON1) is an antioxidant enzyme with three activities: paraoxonase, arylesterase and dyazoxonase. In this study, we evaluated serum paraoxonase and arylesterase activities, and serum lipid hydroperoxide (LOOH) levels in patients with rosacea in comparison to healthy controls.

The study included 39 rosacea patients and healthy controls, consisting of 40 age- and sex-matched healthy volunteers. Serum paraoxonase and arylesterase activities were measured using paraoxon and phenylacetate substrates. Serum LOOH levels were measured with the ferrous ion oxidation-xylenol orange assay.

In rosacea group mean serum paraoxonase and arylesterase activities were 74.54 ± 38.30 U L(-1) and 141.29 ± 22.27 kU L(-1) respectively, which were significantly lower than controls (P = 0.010, 0.005; respectively). Mean serum LOOH level of rosacea group was 8.17 ± 1.91 μmol L(-1) which was significantly higher than controls (P = 0.009). There were no statistically significant differences between the clinical subtypes of the disease, menopause situation or ocular involvement with the respect to the serum paraoxonase and arylesterase activities and LOOH levels (all; P > 0.05).

Serum PON1 enzyme activities have decreased significantly in rosacea. These findings support that decreased PON1 activity and increased oxidative stress may play a role in the pathogenesis of rosacea. Further studies are needed to elucidate the role of PON1 activity in the pathophysiology of rosacea.