Abstract: Objective To investigate the protective effect of Danshenxinkun B against oxidized low-density lipoprotein (ox-LDL)-induced human umbilical vein endothelial cell (HUVEC) injury and explore the underlying mechanism. Methods HUVECs cultured in the presence of 10% fetal bovine serum were treated with ox-LDL (100 μg/mL), ox-LDL+0.1% dimethyl sulfoxide (DMSO), or ox-LDL+Danshenxinkun B (100 ng/mL, dissolved in DMSO) for 24 h. The changes in lactate dehydrogenase (LDH) release was detected, and qRT-PCR was used to detect the mRNA expressions of nuclear factor-κB1 (NF-κB1), nucleotide binding oligomerization domain-like receptor family pyrin domain protein 3 (NLRP3), gasdermin D (GSDMD) and interleukin-1β (IL-1β). The protein expressions of NF-κB1, NLRP3, caspase-1, IL-1β and GSDMD-N were detected with Western blotting. Immunofluorescence assay was performed to examine the changes in GSDMD expression in the cells. Results Compared with the normal control cells, the cells treated with ox-LDL alone or in combination with DMSO exhibited significantly increased LDH release, mRNA expressions of NF-κB1, NLRP3, GSDMD, and IL- 1β and the protein levels of NF- κB1, NLRP3, IL-1β, GSDMD-N and caspase-1 (P<0.01), which were all significantly lowered by treatment with Danshenxinkun B (P<0.05 or 0.01). Danshenxinkun B treatment significantly inhibited GSDMD expression on the cell membrane and restricted its entry into the cell nucleus. Conclusion Danshenxinkun B alleviates ox-LDL-induced HUVEC injury possibly by suppressing pyroptosis mediated by NLRP3 inflammatory bodies and inhibiting the NF-κB/NLRP3 signaling pathway

Key words: NF-κB/NLRP3 signaling pathway; pyroptosis; Danshenxinkun B; oxidized low-density lipoprotein; endothelial cell injury; inflammation; therosclerosis