Inhibitory effects of Paris saponin I, II, Ⅵ and Ⅶ on HUVEC cells through regulation of VEGFR2, PI3K/AKT/mTOR, Src/eNOS, PLCγ/ERK/MERK, and JAK2-STAT3 pathways

Rhizoma Paris is a popular Chinese medicine in clinics. It contains four main saponins which are its major bioactive compounds. These saponins are Paris saponin I, II, VI and VII (PSI, PSII, PSVI and PSVII, respectively). Up to now, the research using HUVEC cells to evaluate the anti-angiogenic activity of four saponins is blank. The purpose of this study was to evaluate the anti-angiogenic properties (also known as angiotoxicity) of the four saponins in Rhizoma Paris on vascular endothelial cells-HUVEC cells, and to investigate the underlying mechanism, which has not been studied before. In this study, MTT assay, Lactate dehydrogenase (LDH) assay, wound healing experiments, transwell cell invasion assay, tubule formation experiment, DAPI staining, AV-PI double staining, and cell cycle analysis were used to determine the effects of Paris saponins. The results showed that, with increases in concentrations of PSI, PSII, PSVI and PSVII, the viability of HUVEC cells decreased significantly. In addition, four saponins dose-dependent enhanced LDH release and inhibited HUVEC cell migration, invasion, and angiogenesis. In terms of mechanism, PSI significantly inhibited protein expression in multiple signaling pathways. In particular, with the VEGF2 as the target, it activate the downstream PI3K / AKT / mTOR, SRC / eNOS, P38, PLCγ / ERK / MERK and JAK2/STAT3 signaling pathways. In conclusion, PSI, PSII, PSVI and PSVII can inhibit endothelial cell proliferation, migration and invasion, block endothelial cell cycle, induce endothelial cell apoptosis, act on protein expression in several anti-angiogenic signaling pathways, and finally inhibit angiogenesis in vitro. This study provides further data support for the clinical application of Paris saponins as antiangiogenic drugs.

Expression of the calcium binding proteins Necab-1,-2 and -3 in the adult mouse hippocampus and dentate gyrus

The family of EF-hand calcium binding proteins is composed of more than 250 members. In search for other neuronal markers, we studied the expression pattern of Necab-1, -2 and -3 in the Ammons horn of adult mice at the gene- and protein levels using in-situ hybridization and immunohistochemistry. The genes for the three Necab's were expressed in specific, non-overlapping areas of the hippocampus. A minority of the Necab-positive interneurons were GABA-ergic, and they virtually never coexpressed one of the classical calcium binding proteins (calretinin, calbindin D-28k and parvalbumin). Necab's are promising new neuronal markers in the brain.