Background: The florets of Carthamus tinctorius L. (Safflower) is an important
traditional medicine for promoting blood circulation and removing blood stasis. However, its bioactive compounds and mechanism of action need further clarification. Objective: This study aims to investigate the effect and possible mechanism of 6-hydroxykaempferol 3,6-di-O-glucoside-7-O-glucuronide (HGG) from Safflower on endothelial injury in vitro, and to verify its anti-thrombotic activity in vivo. Methods: The endothelial injury on human umbilical vein endothelial cells (HUVECs) was induced by
oxygen-
glucose deprivation followed by reoxygenation (OGD/R). The effect of HGG on the proliferation of HUVECs under OGD/R was evaluated by MTT, LDH release, Hoechst-33342 staining, and
Annexin V-FITC apoptosis assay.
RNA-seq, RT-qPCR,
Enzyme-linked
immunosorbent assay and Western blot experiments were performed to uncover the molecular mechanism. The anti-thrombotic effect of HGG in vivo was evaluated using
phenylhydrazine (PHZ)-induced zebrafish
thrombosis model. Results: HGG significantly protected OGD/R induced endothelial injury, and decreased HUVECs apoptosis by regulating expressions of
hypoxia inducible factor-1 alpha (HIF-1α) and
nuclear factor kappa B (NF-κB) at both transcriptome and
protein levels. Moreover, HGG reversed the
mRNA expression of pro-inflammatory
cytokines including IL-1β,
IL-6, and TNF-α, and reduced the release of
IL-6 after OGD/R. In addition, HGG exhibited protective effects against PHZ-induced zebrafish
thrombosis and improved blood circulation. Conclusion: HGG regulates the expression of HIF-1α and NF-κB, protects OGD/R induced endothelial dysfunction in vitro and has anti-thrombotic activity in PHZ-induced
thrombosis in vivo.