Indirubin shows anti-angiogenic activity in an in vivo zebrafish model and an in vitro HUVEC model

Aim of the studyIndirubin is an active ingredient of the traditional Chinese medicine, Dang Gui Long Hui Wan, commonly used for the treatment of chronic myelocytic leukemia (CML) and other inflammatory conditions. These anti-leukemic and anti-inflammatory activities may be mediated by anti-angiogenic action. To investigate the anti-angiogenic activity of indirubin, we tested its inhibitory effect on blood vessel formation in zebrafish embryos and on endothelial cell proliferation in culture.Materials and methodsThe anti-angiogenic activity of indirubin was tested using transgenic zebrafish embryos with fluorescent vasculature and human umbilical vein endothelial cells (HUVECs). Apoptosis was analyzed with a terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) assay.ResultsIndirubin dose-dependently inhibited intersegmental vessel formation in zebrafish embryos. It also inhibited HUVEC proliferation by the induction of cellular apoptosis and cell-cycle arrest at the G0/G1 phase.ConclusionsThe anti-angiogenic activity of indirubin may partly contribute to its anti-leukemic and anti-psoriatic properties and may be valuable for the treatment of diseases with excessive angiogenesis. The zebrafish model of angiogenesis was further validated in this study.

Indirubin effectively affected the blood vessel formation in the drugged zebrafish embryos. Moreover, indirubin dose-dependently suppressed the VEGF-induced proliferation of HUVECs, and also significantly caused cell-cycle arrest at the G0/G1 phase and induced apoptosis in HUVECs. In conclusion, all the promising experimental results support that indirubin is a potential anti-angiogenic compound.Figure optionsDownload as PowerPoint slide