In vitro and ex vivo angiogenic effects of roxarsone on rat endothelial cells

• Roxarsone promotes proliferation of rat endothelial cells.
• Roxarsone induces increased VEGF expression.
• Roxarsone promotes tube formation of cells in vitro.
• Roxarsone promotes microvessel sprouting from aortic rings ex vivo.

Roxarsone, a feed additive, is being used worldwide to promote animal growth. However, the potential effect of roxarsone on angiogenesis has not been extensively characterized. We examined the ability of roxarsone to promote angiogenesis of rat endothelial cells in vitro and from rat aorta rings ex vivo. Endothelial cells from rats were exposed to 0.01–10.00 μM roxarsone, 5 ng/mL vascular endothelial growth factor (VEGF) as a positive control or phosphate buffer saline (PBS) as a negative control. Cell proliferation was measured by MTT assay, and the content of VEGF in supernatants was measured by enzyme-linked immunosorbent assay and Western blotting. A Matrigel-induced tube formation assay was used to evaluate the effects of roxarsone on endothelial cells. Additionally, the total number and length of microvessels sprouted from rat aortic rings were measured for ex vivo investigation of angiogenesis. Results showed that the cell viability and total number and length of capillary-like tube formations after roxarsone treatment was significantly higher than that of negative (P < 0.05), with a maximum effect at 1.00 μM exposure. Furthermore, the number of microvessels sprouted from aortic rings treated for 4 h with 0.1–10.0 μM roxarsone was significantly higher than that of PBS treatment, with a peak value of 1.0 μM. These results further demonstrate the potential of roxarsone to promote angiogenesis in vitro and ex vivo.