Screening Study on the Anti-Angiogenic Effects of Traditional Chinese Medicine - Part II: Wild Chrysanthemum

Background and Aims: Part 2 of our ongoing research with anti-angiogenic effects focuses on Wild chrysanthemum; a heat-clearing and detoxicating Traditional Chinese Medicine (TCM). We screened six heat-clearing and detoxicating TCM and noticed that wild chrysanthemum has a potent anti-angiogenic effect in zebrafish. This study aims to determine the genetic mechanisms underlying the anti-angiogenic effects of wild chrysanthemum. Methods: Wild chrysanthemum was decocted, concentrated, sieved and desiccated to attain the water extract. 200μg/mL wild chrysanthemum water extract (WCWE) was diluted in 0.1% dimethyl sulfoxide (DMSO) and given to zebrafish via fish water. 48h post-fertilization (hpf) fli1a-EGFP transgenic zebrafish were used to assay angiogenesis. mRNA-seq, qRT-PCR assay and a parallel reaction monitor (PRM) were carried out to reveal the underlying mechanisms. Results: WCWE showed a significant anti-angiogenic effect in zebrafish. The results of mRNA-seq showed that there were 1119 genes up-regulated and 1332 genes down-regulated by WCWE. The bioinformatic analysis based on mRNA-seq demonstrated that the proteasome signaling pathway was significantly down-regulated. The results of the qRT-PCR assay were consistent with those of the mRNA-seq assay. The results of the PRM assay showed that nine proteins involved in proteasome signaling and the protein expression level of ctnnb2 were significantly down-regulated. The results of the KEGG pathway analysis based on PRM assay demonstrated that WCWE may have an inhibitory action on the regulatory particle of the proteasome. Conclusion: Wild chrysanthemum has a significant anti-angiogenic effect in zebrafish and it may have an inhibitory action on the regulatory particle of the proteasome. The mechanisms underlying the anti-angiogenic effects of wild chrysanthemum may be related to the down-regulation of proteasome/β-catenin signaling in zebrafish.