Inhibition of ex vivo VEGF-induced angiogenesis by tyrosol and hydroxytyrosol: a quantitative three-dimensional mouse aortic ring model

Abstract

Mediterranean diet foods such as olives, virgin olive oil and wine are sources of tyrosol (TOL) and hydroxytyrosol (HT), which are bioactive compounds. HT has already shown in vitro anti-angiogenic effects in HUVECs. Since TOL is structurally closely related to HT, the aim of the present study was firstly to evaluate the anti-angiogenic properties of TOL regarding inhibition of VEGF-induced VEGFR2 phosphorylation as well as its effects on the intracellular signaling cascade (PLCγ1, Akt and eNOS). Additionally, this paper aims to demonstrate the anti-angiogenic effects of HT and TOL using the ex vivo gold standard mouse aortic ring model. Our results demonstrated that TOL significantly inhibits VEGF-induced VEGFR2 activation in HUVECs, with an IC₅₀ value of 38.33 μM. Additionally, TOL completely blocked PLCγ1 activation, a key component of the VEGFR-2-mediated signalling pathway, while simultaneously increasing the phosphorylation of Akt and eNOS, critical molecules in the regulation of angiogenesis and vasodilation. This study is the first to use the mouse aortic ring model to demonstrate the anti-angiogenic effects of TOL and HT. A significant reduction of capillary sprouting at 68% and 96% was observed for TOL and HT, respectively. These results not only support the potential of TOL and HT as natural anti-angiogenic agents but also offer a new perspective on how diet, especially the Mediterranean diet, may influence the prevention and treatment of angiogenesis-related diseases, such as cancer and cardiovascular diseases.