Puerarin protects against sepsis-associated encephalopathy by inhibiting NLRP3/Caspase-1/GSDMD pyroptosis pathway and reducing blood-brain barrier damage

Puerarin (Pue), an isoflavone compound extracted from Pueraria, has been shown to inhibit inflammation and reduce cerebral edema. The neuroprotective effect of puerarin has attracted much attention in recent years. Sepsis-associated encephalopathy (SAE) is a serious complication of sepsis that causes damage to the nervous system. This study aimed to investigate the effect of puerarin on SAE and elucidate the potential underlying mechanisms. A rat model of SAE was established by cecal ligation and puncture, and puerarin was injected intraperitoneally immediately after the operation. Puerarin was found to improve the survival rate and neuro-behavioral score of SAE rats, alleviate symptoms, inhibit the level of brain injury markers NSE and S1008, and improve the pathological changes in rat brain tissue. Puerarin was also found to inhibit the level of factors related to the classical pathway of pyroptosis, such as NLRP3, Caspase-1, GSDMD, ASC, IL-18, and IL-18. Puerarin also reduced the brain water content and penetration of Evan's Blue dye in SAE rats, and reduced the expression of MMP-9. In the in vitro experiments, we further confirmed the inhibitory effect of puerarin on neuronal pyroptosis by establishing a pyroptosis model in HT22 cells. Our findings suggest that puerarin may improve SAE by inhibiting the classical pathway of NLRP3/Caspase-1/GSDMD-mediated pyroptosis and reducing blood-brain barrier damage, thus playing a role in brain protection. Our study may provide a novel therapeutic strategy for SAE.