Objective: To study the effect of Feiyanning Decoction (FYN), a compound traditional Chinese medicine, on expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) activated by tumor necrosis factor-α (TNF-α) in human lung adenocarcinoma epithelial cell line (A549).
Methods: A549 cells were incubated with rat serum containing FYN for 24 h. Gene expressions of iNOS and COX-2 were determined by quantitative real-time polymerase chain reaction and Western blot. The iNOS-dependent luciferase reporter was transfected for 24 h and the cells were treated with the reagents for 24 h, then the transcriptional activity of iNOS promoter was detected by luciferase assay. The production of NO was determined by diaminofluorescein-2.
Results: FYN significantly inhibited TNF-α-induced expression of iNOS and COX-2 compared with the control group in A549 cells (P<0.01, P<0.01). Also, FYN inhibited the transcriptional activity of the iNOS promoter and reduced NO production compared with the control group (P<0.01, P<0.01).
Conclusion: These results suggest that FYN inhibits iNOS and COX-2 activation induced by TNF-α, therefore, it is expected to develop a new strategy to treat lung cancer.