Fig. 2

Effects of rottlerin, a natural polyphenol compound, on PMA-induced MMP-9 expression in RBA cells. a Time dependence of rottlerin inhibited PMA-induced MMP-9 expression. Cells were pretreated with or without rottlerin (Rott, 1 μM) and then incubated with PMA (1 μM) for the indicated time intervals. b Rottlerin concentration dependently inhibited PMA-stimulated PKC-δ translocation. Cells were pretreated with rottlerin (1 μM) for 1 h and then incubated with PMA (1 μM) for 5 min. The conditioned media (a) and subcellular fractions (b) were collected and assayed for MMP-9 expression by gelatin zymography (a) and Western blot with various PKC antibodies as described under the “Materials and Methods” section (b). Data are expressed as the mean ± SEM (N = 3). ^#P < 0.01, as compared with the respective values of untreated control. *P < 0.05; **P < 0.01, as compared with the respective values of cells stimulated with PMA only. The image represents one of three individual experiments