Ginsenoside Rb3 modulates gut microbiota to alleviate cerebral inflammation and ferroptosis via the NLRP3/NF-κB/GPX4 pathway in rats with cerebral ischemia/reperfusion injury.

Cerebral ischemia/reperfusion injury (CIRI) poses a significant threat to human life and health. Ginsenoside Rb3 (Rb3) is known to exhibit protective effects against myocardial ischemia, its impact on CIRI remains unclear. Therefore, we investigated the protective effects of Rb3 on CIRI and its underlying mechanisms. Our results showed that Rb3 reduced cerebral infarct volume, decreased blood-brain barrier (BBB) permeability, and improved neurological deficits in CIRI rats. Rb3 also mitigated cerebral ferroptosis and alleviated neuroinflammation, as evidenced by decreased iron levels, reduced MDA content, an improved GSH/GSSG ratio, and lower levels of TNF-α, IL-1β, and IL-6, through modulation of the NLRP3/NF-κB/GPX4 pathway. Additionally, Rb3 alleviated intestinal inflammation, improved the intestinal barrier, and corrected gut microbiota dysbiosis and reduced the microbial metabolites TMAO and LPS in CIRI rats. It is noteworthy that in pseudo germ-free rats with CIRI, fecal microbiota transplants (FMT) from Rb3-treated rats conferred similar protective effects as Rb3. Summarily, this study reveals that Rb3 reduces neuroinflammation and ferroptosis in the brains of middle cerebral artery occlusion/reperfusion (MCAO/R) rats via the NLRP3/NF-κB/GPX4 pathway in a gut microbiota-dependent manner.