Objective: To investigate the antitumor effects and mechanism of steroidal saponins of Cestrum nocturnum(SSCN) on human hepatocellular carcinoma xenografts in nude mice in vivo. Method: SSCN from the leaves and twigs of cestrum nocturnum

Linn were separated and their structures were identified by solvent;the animal model of human hepatocellular carcinoma xenografts was constructed by subcutaneous inoculation of hepatocellular carcinoma HepG2 cells into nude mice.The mice were randomly divided into five groups:NS group(0.2 mL)

thalidomide(TLD) group(200 mg·kg-1)

and SSCN low

medium and high dose groups(4

6

8 mg·kg-1).During treatment

tumor size was measured.The mice were killed 30 days later to observe tumor morphology.The angiogenesis was assessed by immunohistochemical staining using anti-vascular endothelia grouth factor(VEGF) and cluster of differentiation 34(CD34) antibodies

the expression of interleukin-8(IL-8) of serum was detected by ELISA. Result: The relative proliferation rate in experimental groups (low

medium and high doses) was 48.26%

42.94% and 41.57%

respectively

and in positive group (thalidomide) the relative proliferation rate was 42.19%. Compared with the NS group

the expression of MVD

VEGF and IL-8 were was markedly lowered in all SSCN treatment groups and TLD group (P<0.01). Conclusion: SSCN has a certain inhibitory effect on tumor nude mice in vivo. The anti-tumor mechanism is probably related to the inhibition of activity of VEGF

MVD and IL-8

and downregulating the expression of proangiogenic factors.