Atorvastatin reduces lipopolysaccharide-induced expression of cyclooxygenase-2 in human pulmonary epithelial cells

Objective: To explore the effects of atorvastatin on expression of cyclooxygenase-2 (COX-2) in human pulmonary epithelial cells (A549). Methods: A549 cells were incubated in DMEM medium containing lipopolysaccharide (LPS) in the presence or absence of atorvastatin. After incubation, the medium was collected and the amount of prostaglandin E₂ (PGE₂) was measured by enzyme-linked immunosorbent assay (ELISA). The cells were harvested, and COX-2 mRNA and protein were analyzed by RT-PCR and western-blot respectively. Results: LPS increased the expression of COX-2 mRNA and production of PGE₂ in a dose- and time-dependent manner in A549. Induction of COX-2 mRNA and protein by LPS were inhibited by atorvastatin in a dose-dependent manner. Atorvastatin also significantly decreased LPS-induced production of PGE₂. There was a positive correlation between reduced of COX-2 mRNA and decreased of PGE₂ (r = 0.947, P < 0.05). Conclusion: Atorvastatin down-regulates LPS-induced expression of the COX-2 and consequently inhibits production of PGE₂ in cultured A549 cells.