Postprandial Paraoxonase 1 Activity Following Consumption of Recommended Amounts of Mixed Meals in Healthy Males.

Aim: Postprandial lipid level increases induce oxidative stress, which is involved in atherogenesis. The antioxidant properties of paraoxonase 1 (PON1) have attracted attention. However, changes in postprandial PON1 levels differ across prior studies, and changes in PON1 lactonase activity, potentially relevant to PON1 physiology, after the consumption of ordinary meals are unknown. Herein we evaluated postprandial serum lipid levels and PON1 changes following mixed-meal consumption of the amounts recommended for ordinary meals.

Methods: Nine healthy male volunteers consumed three different meals in a randomized cross-over design. The test meals were as follows: S, white rice; SMF, S with fat-containing protein-rich main dishes; and SMFV: SMF with vegetable dishes. The serum lipid concentrations and PON1 lactonase and arylesterase activities were determined during a three-hour period after the consumption of these meals.

Results: The postprandial triglyceride levels were higher after consuming the SMF and SMFV meals than after consuming the S meal. Despite postprandial high-density lipoprotein cholesterol being unchanged, PON1 lactonase activity was decreased, while PON1 arylesterase activity was increased in the postprandial state after all test meals. Postprandial changes in lactonase and arylesterase activities did not differ among the test meals.

Conclusions: Inverse changes in PON1 lactonase and arylesterase activities were observed after consuming recommended ordinary meals. This observation provides useful information for choosing PON1 species as postprandial markers.