Theaflavin Attenuation of Atherosclerotic Inflammation via Regulation of Macrophage Pyroptosis Signaling Pathway

Cell pyroptosis, a pro-inflammatory programmed cell death, plays a critical role in atherosclerosis (As) pathogenesis. Our previous studies have shown that theaflavin (TF), a polyphenolic compound, exhibits antioxidant and anti-inflammatory properties and can alleviate the progression of As. However, its impact on macrophage pyroptosis in As remains unexplored. Here, we investigated the effect of TF on pyroptosis in macrophages stimulated by oxidized low-density lipoprotein (ox-LDL). Our results demonstrated that TF significantly inhibited pyroptosis by suppressing the activation of caspase-1, reducing the cleavage of Gasdermin D (GSDMD), and downregulating the expression of NLRP3, interleukin-1β (IL-1β), and interleukin-1α (IL-1α). Additionally, TF decreased the production of reactive oxygen species (ROS), indicating its antioxidant role in mitigating pyroptosis. To verify whether the inhibitory effect of TF on pyroptosis is mediated by reducing ROS, we conducted experiments using N-acetylcysteine (NAC), a specific ROS inhibitor. We set up five groups: control group, ox-LDL group, ox-LDL + TF group, ox-LDL + NAC group, and ox-LDL + TF + NAC group. RT-qPCR detection revealed that the mRNA levels of pyroptosis-related genes in the ox-LDL + NAC group were significantly reduced, and the reduction was more pronounced in the ox-LDL + TF + NAC group, showing a synergistic effect between TF and NAC. These findings highlight that TF holds promise as a therapeutic agent for As by targeting oxidative stress and pyroptosis pathways.