Inhibiting the Proliferation and Inducing Apoptosis of Curcumin on Rat Airway Smooth Muscle Cells

Objective: To investigate the effect of curcumin on the proliferation and apoptosis of airway smooth musc-le cells (ASMCs. Methods Primary ASMCs of rats were cultured by improved tissue-piece digestion inoculation. A model of proliferative ASM-Cs was established induced by PDGF. The anti-proliferation effect to ASMCsof different doses of curcumin was detected by MTT colorimetric assay. Cell apoptosis after being treated with curcumin was assessed by staining with Hoechst 33342 and DNA Ladder. The expression of ERK1/2 and p-ERK1/2 was determined by Western Blot. Results: ① After 12 hours incubated with curcumin, compared with control group, the average cell inhibition rates of 10 μmol/l, 20 μmol/l, 40 μmol/l group were increased significantly (P0.05). After48 hours incubated with curcumin, compared with model group, the average cell inhibition ratio of each group was increased significantly. ② Hyperfluorescence could be observed by staining with Hoechst33342 after 24 hoursbeing treated with 10 μmol/l,20 μmol/l and 40 μmol/l curcumin, and the hyperfluorescence was increased with the increasing dose of curcumin. DNA fragmentations (blue) were detected. ③ Ladders could be detected by apoptotic DNA Ladder kit after being treated with 40 μmol/l curcumin. ④ The levels of p-ERK1/2 protein decreased significantly at 30 minutes and 60 minutes after being treated with 40 μmol/l curcumin and 20 ng/ml PDGF. Conclusions: The proliferation of rat ASMCs was inhibited by curcumin through down-regulated expression of ERK1/2 and the high dose of c-urcumin could induce apoptosis of ASMCs.