Effects of curcumin on tumor angiogenesis and biomarkers,COX-2 and VEGF,in hepatocellular carcinoma cell-implanted nude mice

Abstract

Anti-angiogenic activity of curcumin and effects of curcumin on angiogenic biomarkers, cycloxygenase (COX)-2 and vascular endothelial growth factor (VEGF) levels were investigated. One day after hepatocellular carcinoma cell (HepG2) cells (30 μl of 2×10⁶ cells) were inoculated onto the upper layer of the skin-fold chamber (HepG2-group, n=15), curcumin solutions of 300 and 3000 mg/kg BW were daily oral fed to HepG2-Cur-300 and HepG2-Cur-3000 groups (n=30), respectively. Intravital fluorescence videomicroscopy was performed to monitor neocapillaries in the tumor on days 3, 7 and 14 post-tumor-inoculation, using RITC-dextran (0.1 ml of 0.5% injected intravenously). The tumor neocapillary density (NCD) was evaluated in correlation with the tumor area, using a digital image analysis. The results demonstrated that the NCD of HepG2-groups were significantly increased on day 7 and 14, compared to the aged-matched Sham-groups (p<0.001). The increased NCD on day 7 and 14 were attenuated significantly by daily treatment of curcumin solution (3000 mg/kg BW).The curcumin treatment reduced the tumor-induced over-expression of COX-2 and serum VEGF in HepG2 groups significantly (p<0.001), indicating that curcumin could inhibit tumor angiogenesis. This mechanism might be mediated through reduction of angiogenic biomarkers, COX-2 and VEGF.