Figure 4.

Celastrol nanoparticles dose-dependently inhibit the growth and capillary structure formation of human umbilical vein endothelial cells (EA.hy 926). (A) Morphological variations of EA.hy 926 cells treated with celastrol nanoparticles (0, 1.7, 3.4, 6.8, 13.6, or 27.2 μg/mL) for 72 hours. (B) EA.hy 926 cells treated with either celastrol nanoparticles or blank micelles (0, 1.7, 3.4, 6.8, 13.6, or 27.2 μg/mL) for 72 hours. Water-soluble tetrazolium salt assay was used to determine cell viability after exposure to the nanoparticles. The blank micelles without celastrol showed a cell viability of above 95%. Increasing the amount of celastrol nanoparticles increased the inhibition effect on the EA.hy 926 cells. (C) Celastrol nanoparticles inhibited the tube formation of endothelial cells in Matrigel™ (BD Biosciences, San Jose, CA). EA.hy 926 cells pretreated with or without celastrol nanoparticles were placed in a 96-well plate coated with Matrigel (5 × 10⁴ cells per well). After 10 hours, the tubular structure of the endothelial cells was photographed (magnification: ×200).

Notes: The data are presented as mean ± standard deviation for three independent experiments performed in triplicate. Statistical significance was based on the difference when compared with the control; *P < 0.01.