AUTHOR=Wang Li-Wei , He Jiang-Feng , Xu Hai-Yan , Zhao Peng-Fei , Zhao Jie , Zhuang Cong-Cong , Ma Jian-Nan , Ma Chao-Mei , Liu Yong-Bin 

TITLE=Effects and mechanisms of 6-hydroxykaempferol 3,6-di-O-glucoside-7-O-glucuronide from Safflower on endothelial injury in vitro and on thrombosis in vivo

JOURNAL=Frontiers in Pharmacology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2022.974216

DOI=10.3389/fphar.2022.974216

ISSN=1663-9812

ABSTRACT=<p><bold>Background:</bold> The florets of <italic>Carthamus tinctorius</italic> 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.</p><p><bold>Objective:</bold> This study aims to investigate the effect and possible mechanism of 6-hydroxykaempferol 3,6-<italic>di</italic>-<italic>O</italic>-glucoside-7-<italic>O</italic>-glucuronide (HGG) from Safflower on endothelial injury <italic>in vitro</italic>, and to verify its anti-thrombotic activity <italic>in vivo</italic>.</p><p><bold>Methods:</bold> 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 <italic>in vivo</italic> was evaluated using phenylhydrazine (PHZ)-induced zebrafish thrombosis model.</p><p><bold>Results:</bold> 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 <italic>IL-1β</italic>, <italic>IL-6</italic>, and <italic>TNF-α</italic>, 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.</p><p><bold>Conclusion:</bold> HGG regulates the expression of HIF-1α and NF-κB, protects OGD/R induced endothelial dysfunction <italic>in vitro</italic> and has anti-thrombotic activity in PHZ-induced thrombosis <italic>in vivo</italic>.</p>