Green tea polyphenol epigallocatechin-3-gallate blocks PDGF-induced proliferation and migration of rat pancreatic stellate cells

Figure 5 EGCG inhibited phosphorylation of PDGF β-receptor, ERK, and Akt. PSCs were incubated in the absence or presence of EGCG at the indicated concentrations for 1 h, and then treated with PDGF-BB (at 25 μg/L) for 5 min. A: total cell lysates were prepared, and the total and phosphorylated levels of PDGF β-receptor, Akt, and ERK were determined by Western blotting; B: total cell lysates were prepared and immunoprecipitated with anti-phosphotyrosine antibody. PI3-kinase activity was assessed using PI as a substrate. The arrow denotes the product, PI3-phosphate, resolved by thin layer chromatography.