Gastric cancer (GC) is a malignant tumor with high morbidity and mortality rates worldwide. This study aimed to investigate the effects and mechanisms of action of didymin, a dietary flavonoid glycoside, on GC treatment. Human GC cell lines Hs-746T and AGS were used to assess the effects of didymin on cell viability, cell proliferation, and cell cycle. The results showed that didymin decreased the proliferative capacity of GC cells and blocked cell cycle. Didymin decreased wound healing, invasion, and migration capacities of GC cells. Mitochondrial reactive oxygen species (ROS) levels and mitochondrial membrane potentials were reduced in cells treated with didymin. Network pharmacology analysis revealed that the therapeutic effects of didymin on AGS cells were related to the phosphatidylinositol 3-kinase (PI3K)/Akt pathway. In vivo mouse xenograft studies confirmed that didymin treatment decreased tumor cell proliferation, cell cycle protein levels, and Akt phosphorylation. The present study demonstrated that didymin regulates mitochondrial function and the PI3K/Akt pathway to inhibit cell proliferation and induce apoptosis in GC cells in vitro and in vivo. Therefore, didymin is a promising drug for the treatment of GC.
Neuroinflammation has been proven to exert an important effect on brain injury after intracerebral hemorrhage (ICH). Previous studies reported that Didymin possessed anti-inflammatory properties after acute hepatic injury, hyperglycemia-induced endothelial dysfunction, and death. However, the role of Didymin in microglial pyroptosis and neuroinflammation after ICH is unclear. The current study aimed to investigate the effect of Didymin on neuroinflammation mediated by microglial pyroptosis in mouse models of ICH and shed some light on the underlying mechanisms. In this study, we observed that Didymin treatment remarkably improved neurobehavioral performance and decreased BBB disruption and brain water content. Microglial activation and neutrophil infiltration in the peri-hematoma tissue after ICH were strikingly mitigated by Didymin as well. At the molecular level, administration of Didymin significantly unregulated the expression of Rkip and downregulated the expression of pyroptotic molecules and inflammatory cytokines such as Nlrp3 inflammasome, GSDMD, caspase-1, and mature IL-1β, TNF-α, and MPO after ICH. Besides, Didymin treatment decreased the number of Caspase-1-positive microglia and GSDMD-positive microglia after ICH. Inversely, Locostatin, an Rkip-specific inhibitor, significantly abolished the anti-pyroptosis and anti-neuroinflammation effects of Didymin. Moreover, Rkip binding with Asc could interrupt the activation and assembly of the inflammasome. Mechanistically, inhibition of Caspase-1 by VX-765 attenuated brain injury and suppressed microglial pyroptosis and neuroinflammation by downregulation of GSDMD, mature IL-1β, TNF-α, and MPO based on Locostatin-treated ICH. Taken together, Didymin alleviated microglial pyroptosis and neuroinflammation, at least in part through the Asc/Caspase-1/GSDMD pathway via upregulating Rkip expression after ICH. Therefore, Didymin may be a potential agent to attenuate neuroinflammation via its anti-pyroptosis effect after ICH.