Ginsenoside Rg3 inhibits angiogenesis in gastric precancerous lesions through downregulation of Glut1 and Glut4

Ginsenoside Rg3 (GRg3) is a ginsenoside extracted from Panax ginseng. GRg3 displays multiple pharmacological properties, such as antitumor, anti-inflammatory, antioxidative and antifibrotic properties. However, whether GRg3 inhibits angiogenesis in gastric precancerous lesions (GPLs) and the possible mechanisms remain unknown. GRg3 attenuated gastric intestinal metaplasia and gastric dysplasia, the hallmark of GPL pathology, in rats with MNNG-ammonia compound induced GPLs. Increased CD34+ microvessel density and VEGF expression, which indicate the presence of angiogenesis, were evident in the rats with GPLs. GRg3 administration reduced VEGF protein expression and CD34+ microvessel density. In addition, GRg3 was capable of attenuating microvascular abnormalities. Data analysis revealed that enhanced protein expression of GLUT1, GLUT3 and GLUT4 were present in both human and animal GPL specimens. The administration of GRg3 caused significant decreases in the mRNA and protein expression levels of GLUT1 and GLUT4 in the rats with GPLs. However, the GRg3-treated rats with GPLs did not demonstrate regulatory effects on GLUT3, GLUT6, GLUT10, and GLUT12. Consistent with in vitro results, GRg3 administration significantly reduced the protein expression levels of GLUT1 and GLUT4 in both AGS and HGC-27 human gastric cancer cells in vitro. In conclusion, GRg3 can attenuate angiogenesis and temper microvascular abnormalities in rats with GPLs, which may be associated with its inhibition on the aberrant activation of GLUT1 and GLUT4.