Figure 1.

Galangin (GLG) reduces thrombin-induced pro-form (pro) MMP-9 expression and cell migration in SK-N-SH cells. (A) The cells were pretreated with galangin (1, 3, 10 μM) for 1 h and then incubated with 10 U/mL thrombin for 16 h. The conditioned cell culture media were collected to measure the MMP-9 expression by gelatin zymography. The activity of proMMP-9 was normalized to that of MMP-2. The cell lysates were analyzed by western blot to determine the expression of glyceraldehyde-3-phosphate dehydrogenase (GAPDH), serving as the marker for the cell viability during these treatments. (B) The cells were pretreated with galangin (10 μM) for 1 h and then incubated with 10 U/mL thrombin for 16 h (mRNA expression) or 24 h (promoter activity). The mRNA expression and promoter activity of MMP-9 were determined by real-time PCR and promoter assay, respectively. (C) The cells were plated on 6-well culture plates, grown to confluence, and then starved with serum-free medium for 24 h. At that point, the cells were pretreated with galangin (3 or 10 μM) for 1 h and then incubated with thrombin for 48 h. Images of the migratory cells were taken at the indicated conditions. The data are expressed as mean ± SEM of three independent experiments. ^# p < 0.01, as compared with the cells exposed to thrombin alone. −: no treatment with Thrombin; DM: DMSO (dimethyl sulfoxide).