Dihydrotanshinone I Attenuates Atherosclerosis via Inhibiting NLRP3 Inflammasome Activation and Modulating Gut Microbiota

Abstract

Atherosclerosis (AS), a primary contributor to cardiovascular disease, is driven by hyperlipidemia, chronic inflammation, and gut dysbiosis. Although Salvia miltiorrhiza Bunge (Danshen) has long been used to treat atherosclerotic disorders, its most potent anti-inflammatory constituent remains unclear. Screening 12 constituents from Danshen revealed that dihydrotanshinone I (DHT) was the most potent inhibitor of NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) inflammasome activation in vitro. In an atherosclerotic mouse model, DHT treatment effectively attenuated dyslipidemia and reduced atherosclerotic plaque burden in the aorta and aortic sinus. Mechanistically, DHT significantly downregulated the aortic mRNA expression of key inflammasome components (NLRP3, ASC, Caspase-1, and IL-1β) and significantly suppressed the aortic protein levels of intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1). Furthermore, gut microbiota analysis indicated that DHT alleviated high-fat diet-induced gut dysbiosis by restoring gut microbial diversity. This was characterized by a decrease in pathobionts (Rikenellaceae_RC9_gut_group, Muribaculum, and [Eubacterium]_ventriosum_group) and an increase in beneficial genera (Akkermansia and Allobaculum). Fecal microbiota transplantation (FMT) confirmed that these atheroprotective effects were transferable via the gut microbiota, highlighting the key role of microbial modulation. Collectively, DHT exerts its anti-atherosclerotic effects by simultaneously improving lipid metabolism, inhibiting NLRP3 inflammasome activation, and restoring gut microbial homeostasis.