Exploring the effect and mechanism of Baihu-Guizhi Decoction on rheumatoid arthritis with hot syndrome from the angiogenesis regulatory network mediated by VEGF/VEGFR2/PI3K/AKT signaling pathway

Baihu-Guizhi Decoction (BHGZD), a prescription from ''Synopsis of the Golden Chamber'', has a definite clinical effect in the treatment of rheumatoid arthritis (RA). However, the research on the mechanism of this prescription mainly focuses on the regulation of inflammatory response and immune function, and its efficacy and mechanism of inhibiting synovial angiogenesis have not been reported. In the current study, transcriptomics data mining, biological network analysis and ''in vivo-in vitro'' experimental verification integrated research strategy to explore the potential and molecular mechanism of BHGZD in RA synovial angiogenesis with hot syndrome. Animal welfare and experimental procedures follow the regulations of the Animal Ethics Committee of China Academy of Chinese Medical Sciences. The results of network analysis showed that the candidate network targets of BHGZD intervention in RA with hot syndrome were significantly involved in multiple angiogenesis regulation related pathways. Among them, vascular endothelial growth factor A-vascular endothelial growth factor receptor 2 (VEGFA-VEGFR2) signaling pathway contains multiple BHGZD candidate network targets, such as VEGF, phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT), etc. Further experimental results showed that BHGZD could effectively reduce the expression of CD31 in knee synovium, the expression level of VEGF in serum, the activity of endothelial nitric oxide synthase (eNOS), phosphorylated VEGFR2 (p-VEGFR2), p-PI3K and p-AKT in joint tissue of adjuvant-induced arthritis rats with hot syndromes, the migration and invasion activity of HUVEC and MH7A cells, and the lumen formation activity of HUVEC cells and improve the expression level of endostatin in serum. In conclusion, BHGZD has the potential to alleviate excessive synovial angiogenesis in RA with hot syndrome, and its mechanism may be related to the intervention of VEGF/VEGFR2/PI3K/AKT signaling pathway.