The Polyphenols (−)-Epigallocatechin-3-Gallate and Luteolin Synergistically Inhibit TGF-β-Induced Myofibroblast Phenotypes through RhoA and ERK Inhibition
Figure 6
EGCG and luteolin reduce RhoA activation and reverse TGF-β-induced fibronectin expression.
(A) WPMY-1 cells were pre-treated 8 hours with 20 µM GGTI-2133, 20 µM EGCG or 20 µM luteolin in the presence or absence of 10 µM or 40 µM geranylgeranylpyrophosphate (GGPP) prior to co-treatment with TGF-β for an additional 24 hours. Western blot was used to determine levels of the indicated proteins. (B) WPMY-1 cells were pre-treated 30 minutes in 1% FBS DMEM with EGCG (E) or luteolin (L) prior to addition of TGF-β for an additional 15 minutes. Rhotekin-RBD beads were used to pulldown active RhoA. (C) WPMY-1 cells were pulsed with TGF-β for 24 hours, washed with PBS, then chased with 40 µM EGCG or luteolin with or without TGF-β for an additional 24 hours.