AimTo study the effect of lovastatin on expression and activity of matrix metalloproteinase-9 (MMP-9) in a human umbilical vein endothelial cells (HUVECs) line.MethodsCultured HUVECs were stimulated by 20 μg/L tumor necrosis factor-alpha (TNF-α), and then incubated with 0.05-1.35 μmol/L of lovastatin for 0-24 h.The protein and mRNA level were detected by Western blotting and reverse transcription polymerase chain reaction (RT-PCR) respectively, and the activity of MMP-9 was analyzed by gelatin zymography.ResultsMMP-9 expression was induced by TNF-α in HUVECs, lovastatin attenuated both expression and activity of MMP-9 in a time and dose-dependent manner.0.05 μmol/L lovastatin inhibited MMP-9 expression in mRNA level, but not in protein level, but activity of MMP-9 cannot be inhibited by 0.05 μmol/L lovastatin.Other concentration of lovastatin groups can inhibit MMP-9 expression both in mRNA and protein levels, including activity of MMP-9, the maximum inhibitory effect was induced by 1.35 μmol/L lovastatin.ConclusionExpression and activity of MMP-9 can be inhibited by lovastatin in HUVECs.