Stability of angiogenic agents, ginsenoside Rg1 and Re, isolated from Panax ginseng: in vitro and in vivo studies.

The study was designed to investigate the stability of ginsenoside Rg(1) (Rg(1)) and Re (Re), two natural herbal compounds isolated from Panax ginseng, based on their activity to promote angiogenesis in vitro and in vivo. After being treated at different temperatures, pHs, and solvent species for distinct durations, the remaining activities of Rg(1) and Re on human umbilical vein endothelial cell (HUVEC) proliferation, migration, and tube formation were examined in vitro. Additionally, the remaining activity of each treated test agent, mixed in a growth factor-reduced Matrigel, in stimulating angiogenesis was evaluated subcutaneously in a mouse model. Basic fibroblast growth factor (bFGF) was used as a control. It was found in vitro that HUVEC proliferation, migration in a Transwell plate, and tube formation on Matrigel were all significantly enhanced in the presence of bFGF, Rg(1), or Re. However, after being treated at different temperatures, pHs, or solvent species, the remaining activity of bFGF on HUVEC behaviors reduced significantly. This observation was more significant with increasing the duration of treatment. In contrast, the activities of Rg(1) and Re remained unchanged throughout the entire course of the study. The in vivo results observed on day 7 after implantation showed that the blank control (Matrigel alone) was slightly vascularized. In contrast, the density of neo-vessels in the Matrigel plug mixed with bFGF, Rg(1), or Re was significantly enhanced. However, after being treated, the density of neo-vessels was significantly reduced in the Matrigel plug mixed with bFGF, while those of Rg(1) and Re remained unchanged. The aforementioned results suggested that Rg(1) and Re could be a novel group of nonpeptide angiogenic agents with a superior stability and may be used for the management of tissue regeneration.

A natural compound (ginsenoside Re) isolated from Panax ginseng as a novel angiogenic agent for tissue regeneration.

PURPOSE: The primary challenge for tissue engineering is to develop a vascular supply that can support the metabolic needs of the engineered tissues in an extracellular matrix. In this study, the feasibility of using a natural compound, ginsenoside Re, isolated from Panax ginseng in stimulating angiogenesis and for tissue regeneration was evaluated. METHODS: Effects of ginsenoside Re on the proliferation, migration, and tube formation of human umbilical vein endothelial cells (HUVECs) were examined in vitro. Additionally, angiogenesis and tissue regeneration in a genipin-fixed porous acellular bovine pericardium (extracellular matrix; ECM) incorporated with ginsenoside Re implanted subcutaneously in a rat model were investigated. Basic fibroblast growth factor (bFGF) was used as a control. RESULTS: It was found that HUVEC proliferation, migration in a Transwell plate, and tube formation on Matrigel were all significantly enhanced in the presence of bFGF or ginsenoside Re. Additionally, effects of ginsenoside Re on HUVEC proliferation, migration, and tube formation were dose-dependent and reached a maximal level at a concentration of about 30 microg/ml. The in vivo results obtained at 1 week postoperatively showed that the density of neocapillaries and the tissue hemoglobin content in the ECMs were significantly enhanced by bFGF or ginsenoside Re. These results indicated that angiogenesis in the ECMs was significantly enhanced by loading with bFGF or ginsenoside Re. At 1 month postoperatively, vascularzied neo-connective-tissue fibrils were found to fill the pores in the ECMs loaded with bFGF or ginsenoside Re. CONCLUSIONS: The aforementioned results indicated that like bFGF, ginsenoside Re-associated induction of angiogenesis enhanced tissue regeneration, supporting the concept of therapeutic angiogenesis in tissue-engineering strategies.