(A) Cheiradone inhibits EC differentiation into capillary like structures on Matrigel. Cells were treated with either cheiradone (control, 0–3.85 μM) or cheiradone (0–3.85 μM) with VEGF (10 ng/ml). Values significantly different from VEGF alone (p < 0.05) are shown by *. (B) Representative photomicrographs show; i HDMEC, ii HDMEC treated with cheiradone; 7.7 μM, iii HDMEC treated with VEGF 10 ng/ml, iv HDMEC treated with VEGF and cheiradone, 7.7 μM. Experiments were performed and the number of closed tubes was determined as described above. Results are the mean of three experiments. Incomplete tube formation was noted in the presence of cheiradone (ii) but extensive tube formation with VEGF (iii). In the presence of cheiradone the effect of VEGF was abolished (iv).