Abstract
Lymphangiogenesis plays important roles in physiological and pathological conditions. The induction of new lymphatic vessel formation is important for promoting wound repair and treatment in lymphatic diseases such as lymphedema. Polygonati Rhizoma (root of Polygonatum kingianum Coll. et Hemsl.), a traditional Chinese herbal medicine, has been shown to exhibit a variety of pharmacological activities in vivo and in vitro, such as anti-aging, hypoglycemic, neuroprotective and neuroremodeling effects. The network formation process of neurons is similar to the vascular system. The propose of this study was to investigate the effect of Polygonati Rhizoma methanol extract on lymphangiogenesis by using conditionally immortalized lymphatic endothelial (TR-LE) cells, a newly developed cell line originating from the thoracic duct of a transgenic rat expressing the temperature-sensitive SV40 large T-antigen. The results show that non-toxic doses of Polygonati Rhizoma at concentrations of 20 μg/ml and 50 μg/ml produced a slight and significant increase in capillary-like tube formation length of TR-LE cells (increased 15.8% and 40.7% from control, respectively) (p<0.01) after 4 h incubation on Matrigel. In addition, 50 μg/ml Polygonati Rhizoma significantly increased adhesion ability of TR-LE cells at 30 min (increased 44% from control) (p<0.05) and migration at 4 h of incubation (increased 37.5% from control) (p<0.01). However, the expansion of TR-LE cells treated with this extract (50 μg/ml) for 24 and 48 h did not show any statistically significant effect on cell proliferation. Here, we report, for the first time, that Polygonati Rhizoma induces lymphangiogenesis in vitro. This finding may provide an attractive reagent for pro-lymphangiogenic therapy.