In vitro and in vivo structure and activity relationship analysis of polymethoxylated flavonoids: identifying sinensetin as a novel antiangiogenesis agent.

Scope: Polymethoxylated flavonoids are present in citrus fruit in a range of chemical structures and abundance. These compounds have potential for anticarcinogenesis, antitumor, and cardiovascular protective activity, but the effect on angiogenesis has not been well studied.

Methods And Results: Human umbilical vein endothelial cells (HUVECs) in vitro and zebrafish (Danio rerio) in vivo models were used to screen and identify the antiangiogenesis activity of seven polymethoxylated flavonoids; namely, hesperetin, naringin, neohesperidin, nobiletin, scutellarein, scutellarein tetramethylether, and sinensetin.

Nobiletin, a polymethoxylated flavonoid from citrus, shows anti-angiogenic activity in a zebrafish in vivo model and HUVEC in vitro model.

Traditional Chinese medicinal herbs are a rich source of compounds with reported anti-inflammatory and anti-carcinogenic effects. Growing evidence shows the codependence of chronic inflammation and angiogenesis, and the potential benefits of targeting angiogenesis in the treatment of chronic inflammation and targeting inflammation in the treatment of diseases with impaired angiogenesis. We hypothesized that the anti-inflammatory activity of the natural compounds may owe at least some of its efficacy to their anti-angiogenic activity and hence we investigated the anti-angiogenic activity of these compounds in vivo in zebrafish embryos and in vitro in human umbilical vein endothelial cells (HUVECs).

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

Aim Of The Study: Indirubin 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.