OBJECTIVETo investigate the in vitro effects of the antibacterial drugs, meropenem trihydrate, piperacillin sodium, and cefoperazone sodium, on the activity of human serum paraoxonase (hPON1).

METHODShPON1 was purified from human serum using simple chromatographic methods, including DEAE-Sephadex anion exchange and Sephadex G-200 gel filtration chromatography.

RESULTSThe three antibacterial drugs decreased in vitro hPON1 activity. Inhibition mechanisms meropenem trihydrate was noncompetitive while piperacillin sodium and cefoperazone sodium were competitive.

CONCLUSIONSOur results showed that antibacterial drugs significantly inhibit hPON1 activity, both in vitro, with rank order meropenem trihydrate piperacillin sodium cefoperazone sodium in vitro.