(-)-Epigallocatechin Gallate Reduces Platelet-Derived Growth Factor-BB-Stimulated Interleukin-6 Synthesis in Osteoblasts: Suppression of SAPK/JNK

Figure 2

Effect of EGCG on the PDGF-BB-induced autophosphorylation of PDGF receptor β in MC3T3-E1 cells. The cultured cells were pretreated with the indicated doses of EGCG or vehicle for 60 minutes, and then stimulated by 50 ng/mL PDGF-BB or vehicle for 3 minutes. The extracts of cells were subjected to SDS-PAGE with subsequent Western blotting analysis with antibodies against phospho-specific PDGF receptor β or PDGF receptor β. The histogram shows quantitative representations of the levels of PDGF-BB-induced autophosphorylation obtained from laser densitometric analysis of three independent experiments. Each value represents the mean±SEM of triplicate determinations. Similar results were obtained with two additional and different cell preparations.