Enhanced inhibition of protein disulfide isomerase and anti-thrombotic activity of a rutin derivative: rutin:Zn complex.

Rutin is a flavonoid that exists in plants and in commonly consumed foods. In recent years, rutin has been demonstrated to have anti-thrombotic efficacy through its inhibition of protein disulfide isomerase. However, the low aqueous solubility and high dose limit the therapeutic applications of rutin. In this study, we found that the chelation of zinc ions increased rutin aqueous solubility by 4-fold. More importantly, the thus-formed rutin:Zn complex inhibited PDI activity more potently than rutin itself. In a murine model with electric current-induced arterial thrombosis, the rutin:Zn complex slowed mouse arterial occlusion compared to rutin without increasing bleeding risk. Thus, the zinc chelation not only improved rutin aqueous solubility but achieved stronger inhibition of PDI. Furthermore, zinc chelation of a selected list of flavonoids containing the adjacent keto and phenoxy groups also increased their inhibition of PDI. Hence, our study provides a strategy to promote flavonoids' anti-thrombotic properties.