The flavonoid hydroxygenkwanin reduces inflammation and neointimal formation.

Abnormal vascular smooth muscle cell (VSMC) proliferation and migration play crucial roles in neointimal hyperplasia and restenosis progression in response to stimulation with various inflammatory cytokines, such as platelet-derived growth factor-BB (PDGF-BB) and tumour necrosis factor-α (TNF-α). Hydroxygenkwanin (HGK) exerts remarkable anti-inflammatory, antitumour, antiproliferative and antimigratory effects. The aim of the study was to elucidate the therapeutic effect and regulatory mechanism of HGK on neointimal hyperplasia. The results showed that HGK inhibited the abnormal proliferation, migration, and inflammation of PDGF-BB- or TNF-α-treated VSMCs through regulation of the PDK1/AKT/mTOR pathway. In addition, HGK promoted circulating endothelial progenitor cell (EPC) chemotaxis. In an in vivo assay, HGK dramatically enhanced re-endothelization and reduced neointimal hyperplasia after femoral artery denudation with a guide wire in mice. These results suggest that HGK can serve as a therapeutic target drug or a functional food supplement for the treatment of restenosis.