Cyanidin-3--glucoside promotes late-stage venous thrombus resolution in mice, accompanied by reduced macrophage M1-associated inflammation and attenuated HIF-1α-linked signaling.

Abstract

Deep vein thrombosis (DVT) is characterised by thrombus formation in the deep veins, and efficient thrombus resolution is essential to restore venous patency and prevent life-threatening complications. Cyanidin-3--glucoside (C3G), a major dietary anthocyanin with anti-inflammatory and antioxidant activities, has not previously been investigated in the context of venous thrombus resolution. Here, we examined the effects of C3G on stasis-induced DVT in mice and explored the underlying mechanisms, with a focus on macrophage function and hypoxia-inducible factor 1α (HIF-1α) signalling. Prophylactic oral C3G markedly reduced thrombus weight, length and cross-sectional area 14 days after inferior vena cava ligation, accompanied by increased intrathrombotic CD68macrophage abundance, suppression of M1 macrophage polarization and attenuation of intrathrombotic inflammatory responses. C3G increased systemic and local superoxide dismutase activity, decreased lactate and malondialdehyde levels and downregulated HIF-1α together with its downstream glycolytic enzymes pyruvate kinase M2 and lactate dehydrogenase A within thrombi. In bone marrow-derived macrophages, C3G selectively inhibited lipopolysaccharide and interferon-γ-induced M1 polarization and cytokine production without affecting interleukin-13-driven M2 polarization. In a CoCl-induced hypoxia-mimetic model, C3G reduced reactive oxygen species generation, restored antioxidant capacity, limited apoptosis and reduced markers of hypoxia and glycolysis regulated by HIF-1α. These findings indicate that C3G is associated with late-stage thrombus resolution in parallel with modulating macrophage polarization and HIF-1α-mediated metabolic adaptation, supporting further evaluation of this food-derived compound as a candidate adjunct for modulating the thrombus microenvironment.