Figure 1.

Norcantharidin (NCTD) inhibits cell viability in both human umbilical vein endothelial cells (HUVECs) and LOVO cells. (a) The chemical structure of NCTD with a molecular weight 186.15 g. (b) Norcantharidin inhibits vascular endothelial growth factor (VEGF)‐induced cell viability in dose‐dependent manner. HUVECs (2 × 10⁴ cells/well) were starved with 0.1% fetal bovine serum (FBS) medium and then treated with or without VEGF (4 ng/mL) and different concentrations of NCTD for 24 h. Cell viability was quantified by MTT assay (*P < 0.05, **P < 0.01, ***P < 0.001 versus VEGF alone). (c) Effects of NCTD on HUVEC viability under normal culture condition. Human umbilical vein endothelial cells (2 × 10⁴ cells/well) were treated with different concentrations of NCTD for 24 h (*P < 0.05, **P < 0.01, ***P < 0.001 versus control). (d) Norcantharidin inhibits colorectal cancer cell (LOVO) viability (the treatment is the same as C). Column, mean from three different experiments with six duplicates; bar, SE.