Normalizing the disordered
tumor vasculature, rather than blocking it, is a novel method for anticancer
therapy. Astragali
polysaccharide (APS) and
curcumin were reported to be active against
carcinomas. However, the effect and mechanism of the combination of APS and
curcumin on vascular normalization in
hepatocellular carcinoma (HCC) was not clear. In the present study, effects of combined APS and
curcumin on
tumor vascular normalization were evaluated in HepG2
tumor-bearing mice. Photoacoustic tomography (PAT) was performed to observe the morphological structure of
tumor vessels in vivo. The microstructure of the
tumor vessels was also analyzed through scanning electron microscopy. Additionally, the expression of CD31 and NG2 was analyzed by immunohistochemical staining.
Tumor vessels of HepG2
tumor-bearing mice treated with the combination were sparse with uniform growth, morphology rules, and complete vascular walls, which had fewer branches and sprouts. ECs of
tumor vessels were arranged regularly and were tightly connected, tending toward normalization. The expression of CD31 was reduced while NG2 was increased significantly by the combination of APS and
curcumin. The results indicated that APS and
curcumin in combination showed a better effect on inhibiting
tumor growth in an orthotopic nude-mouse model of HCC. More important, the combination induced normalization of
tumor vascular better than APS or
curcumin administration alone, improving the morphological structure of
tumor vessels and promoting maturation of
tumor vessels. The results of the present study provided a reasonable possibility for combination
therapy of APS and
curcumin in the treatment of HCC via
tumor vascular normalization.