Potential of Forsythoside I as a therapeutic approach for acute lung injury: Involvement of TXNIP/NLRP3 inflammasome

To explore the role of Forsythoside I (FI) in acute lung injury (ALI) mouse and its underling mechanism. The cell models of ALI are constructed by LPS induction. After pretreatment with different concentrations of FI, the lung injury is assessed by pathological changes of lung tissues and cell apoptosis. The cell viability, levels of pro-inflammatory cytokines, and the activation of TXNIP/NLRP3 pathway are inspected to investigate whether the effect of FI on inflammatory response is exerted by regulating the TXNIP/NLRP3 pathway. LPS induces inflammatory cell infiltration, tissue necrosis and pulmonary interstitial edema of mouse tissues, and LPS increases the protein concentration and levels of pro-inflammatory factors in mouse BALF. Additionally, enhanced cell apoptotic level, increased W/D ratio and MPO activity, as well as suppressed SOD activity are observed in LPS-induced mouse models. Those inflammation response, oxidative stress and lung injury can be attenuated by FI (12.5 mg/kg, 25 mg/kg, 50 mg/kg) in a dose-dependent manner. Meanwhile, both in vitro and in vivo studies reveal that FI can lead to suppressed TXNIP expression and inactivated NLRP3 inflammasomes. TXNIP is an upstream target of NLRP3, and FI mitigates ALI by decreasing TXNIP to block NLRP3 inflammasomes. FI protects against ALI through the mediation of TXNIP/NLRP3 inflammasome axis and therefore has a certain potential for ALI treatment.