Discovery based on SPR drug chip that corilagin alleviates acute lung injury in mice by inhibiting necroptosis through targeting RIPK1/RIPK3/MLKL pathway

Necroptosis, a necrotic type of regulated cell death, is important in a variety of tissues and disorders, including sepsis. It is predominantly mediated in a caspase-independent manner by receptor-interacting protein kinase 1 (RIPK1), RIPK3, and mixed lineage kinase domain-like (MLKL). Diseases related to necroptosis are often accompanied by excessive inflammatory responses. Corilagin, a gallotannin with potent anti-inflammatory and antioxidant properties, has gained more recognition. However, its impact on necroptosis and associated disorders remains unknown. Here, we employ an SPR-LCMS/MS (surface plasmon resonance-liquid chromatography-tandem mass spectrometry) screening approach to explore corilagin's target proteins and find it binds to necroptosis-related proteins. In vitro, corilagin prevents necroptosis caused by either TSI (tumor necrosis TNF-α in conjunction with LCL-161 (a Smac mimic) and pan-caspase inhibitor IDN-6556), or lipopolysaccharide (LPS) in combination with IDN-6556. It also inhibits the phosphorylation of MLKL, RIPK1, and RIPK3, and prevents the development of necrosomes during necroptotic induction. Moreover, corilagin alleviates the TSI-induced loss of mitochondrial membrane potential, a hallmark of necroptosis-associated mitochondrial dysfunction and the formation of mitochondrial reactive oxygen species. Furthermore, in a mouse model of sepsis associated with necroptosis, corilagin treatment lessens the severity of LPS-induced acute lung injury in a mouse model of sepsis linked to necroptosis, which is accompanied by a reduction in MLKL phosphorylation in lung tissues. Collectively, our findings suggest that corilagin attenuates RIPK1/RIPK3/MLKL signaling, likely by reducing mitochondrial reactive oxygen species production, thereby inhibiting necroptosis and providing protection against LPS-induced acute lung injury.