The Generation of Hematopoietic Progenitor Cells from Endothelial Cells by Silymarin.

Background: The generation of hematopoietic cells from endothelial cells may determine a novel approach for the production of blood cells. Regenerative functions of Silymarin, a mixture of polyphenolic flavonoids derived from milk thistle, have previously been reported. The purpose of this study was to investigate the direct effect of Silymarin on conversion of endothelial cells to hematopoietic cells. Methods: The effect of Silymarin on CD34, CD45, and vascular endothelial growth factor receptor-2 (VEGFR-2) markers along with all the main hematopoietic lineage markers in human umbilical vein endothelial cells (HUVEC) were investigated by flow cytometry and immunocytochemistry. Results: Treatment of HUVEC cells with Silymarin after 24 hours significantly increased the number of the cells expressing CD34 and CD45 markers. Although the percentage of VEGFR-2 and CD13 was increased, the changes were not statistically significant during 24 hours. No significant expression of the rest of the hematopoietic lineage specific markers was found during this time. Conclusions: Taken together, our preliminary findings demonstrated the potential of Silymarin to switch human umbilical vein endothelial cells into hematopoietic progenitor cells.

A comparative study between platelet-rich plasma and platelet-poor plasma effects on angiogenesis.

Platelet-rich plasma (PRP) has been established as an autologous source for therapeutic angiogenesis. The purpose of this study was to evaluate PRP angiogenic effects compared to platelet-poor plasma (PPP) in vitro and in vivo. The effects of PRP on vascular endothelial growth factor receptor-2 (VEGFR2) and CD34 expression were evaluated using real-time PCR, flow cytometry, western blot, immunocytochemistry and pathological study, as were carried out in both human umbilical endothelial cell culture and rat skin. Our findings indicated significant effect of PRP and PPP on VEGFR2 and CD34 expression by human umbilical vein endothelial cells, which was greater in latter. These effects, however, were confirmed by demonstrating an earlier angiogenic effect of PPP in vivo when compared to PRP. The findings of the present study as the first comparative study of PRP versus PPP are novel. Nevertheless, further studies are needed to clarify the underlying mechanism of these findings to improve the therapeutic effects of PRP and PPP.