Figure 4.

EGb^® 761 suppresses ERK, MEK and Raf‐1 kinase activity via activation of tyrosine phosphatases. HMECs were pre‐treated with NaF (1 mM, 30 min.; A) or Na₃VO₄ (100 μM, 30 min.; B). Subsequently, the cells were stimulated with EGb^® 761 (500 μg/ml, 30 min.) and FGF (5 ng/ml, 30 min.). (C) HUVECs were pre‐incubated with Na₃VO₄ and stimulated with EGb^® 761 and FGF. (D) The stimulation scheme was the same as in (C). Representative Western blots are shown for phospho‐Raf‐1 (Ser338/Tyr341) at both high and low intensity. Additionally, Raf kinase activity (indicated as phospho‐MEK) was determined. (E) HMECs were pre‐treated with EGb^® 761 and subsequently exposed to PMA (50 nM, 10 min.).