Effect of Robinia pseudoacacia Leaf Extract on Interleukin-1β-mediated Tumor Angiogenesis.

Interleukin (IL)-1β is a pro-inflammatory cytokine that has recently been established as a stimulator of angiogenesis via regulation of proangiogenic factor expression in the tumor microenvironment. This study aimed to demonstrate the inhibitory effects of Robinia pseudoacacia leaf extract (RP) on IL-1β-mediated tumor angiogenesis.Secreted embryonic alkaline phosphatase (SEAP) reporter gene assay, ex vivo and in vitro tube formation assay, western blot, and quantitative PCR were used to analyze the inhibitory effect of RP on IL-1β-mediated angiogenesis.RP inhibited secretion of SEAP, blocked IL-1β signaling, and inhibited IL-1β-mediated angiogenesis in ex vivo and in vitro assays. RP inhibited nuclear translocation of NF-ĸB by suppressing phosphorylation of IL-1β signaling protein kinases and inhibited mRNA expression of IL-1β-induced pro-angiogenic factors including VEGFA, FGF2, ICAM1, CXCL8, and IL6.RP suppressed IL-1β-mediated angiogenesis and, thus, could be a promising agent in anticancer therapy.