[Inhibitory effect of tetrandrine on angiogenesis]

Angiogenesis plays an important role in tumorigenesis and metastasis. This study was to investigate the inhibitory effect and mechanism of tetrandrine on angiogenesis in vitro and in vivo.

MTT assay was used to observe the effect of tetrandrine on the proliferation of human umbilical vein endothelial cells (HUVECs) and human colorectal carcinoma LoVo cells. Transwell migration assay and tube formation assay were used to observe the impact of tetrandrine on cell migration and tube forming ability of HUVECs. LoVo cells were transplanted into nude mice. Microvessel density (MVD) was measured in nude mouse xenografts after intragastric administration of tetrandrine.

Tetrandrine (2-8 microg/mL) inhibited the proliferation of HUVECs (24.6%-76.9%) and LoVo cells (11.6%-14.0%) after 48 h treatment. When HUVECs were incubated with 2-8 microg/mL tetrandrine, the number of tubules was reduced and the lumen lost its integrity after 24 h; the number of migrating HUVECs was decreased after 12 h as compared with the control group (P < 0.001). Furthermore, MVD was much less in LoVo cell xenografts treated with 80mg/kg tetrandrine than in those treated with normal saline (P = 0.035).

Tetrandrine effectively suppresses angiogenesis in vitro, which may be through inhibiting cell proliferation, migration and tube-formation, inducing apoptosis and suppressing DNA synthesis of HUVECs. Tetrandrine also has an antiangiogenic effect on LoVo cell xenografts in nude mice.