EB did not enhance the activity of tyrosine phosphatases.

<p><b>(A)</b> A549 cells were stimulated by IL-6 (10 ng/ml) for 15 min. The media were then replaced by fresh media without IL-6 and incubated with or without EB (20 μM) for different time periods (0–240 min). Whole cell lysates were processed for western blot analysis using antibodies as indicated. <b>(B)</b> A549 cells were pre-treated with sodium orthovanadate (50 μM), EB (20 μM) or their mixture for 2 h, then stimulated with IL-6 for 15 min. Whole cell lysates were processed for western blot analysis using antibodies as indicated.