1.Mechanism of Huanglian Jiedutang in Inhibiting Activation of NLRP3 Inflammasomes and Ameliorating Acute Liver Injury in Septic Mice
Ruizhu ZHAO ; Zhengyang HUA ; Yuhang WANG ; Xinyue REN ; Dingxing FAN ; Shilei LOU ; Hui YAN ; Cong SUN
Chinese Journal of Experimental Traditional Medical Formulae 2024;30(22):27-34
ObjectiveTo explore the mechanism of Huanglian Jiedutang in inhibiting the pyroptosis mediated by NOD-like receptor protein 3 (NLRP3) inflammasomes and alleviating the acute liver injury (ALI) induced by lipopolysaccharide (LPS) in the mouse model of sepsis. MethodFifty-four male C57BL/6 mice were randomized into blank, model, low- (3.08 g·kg-1), medium- (6.15 g·kg-1), and high-dose (12.30 g·kg-1) Huanglian Jiedutang, and positive control (dexamethasone) groups (n=9). The mice were administrated with Huanglian Jiedutang at different doses by gavage for 7 days, and then LPS (15 mg·kg-1) was injected intraperitoneally for the modeling of sepsis. In the positive control group, dexamethasone (0.05 g·kg-1) was injected intraperitoneally 1.5 h after modeling, and the mouse sepsis score (MSS) was recorded 12 h after modeling. The mice were sacrificed for the collection of blood and liver tissue samples. The levels of alanine transaminase (ALT) and aspartate transaminase (AST) were measured by a biochemical analyzer. The levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-1β, and IL-18 in the serum were measured by enzyme-linked immunosorbent assay kits. Hematoxylin-eosin staining was used to observe the pathological changes in the liver tissue. The content of NLRP3 was observed by the immunofluorescence assay. The expression of apoptosis-associated speck-like protein containing CARD (ASC) was detected by immunohistochemistry. The protein levels of NLRP3, ASC, Caspase-1, and gasdermin D (GSDMD) in the liver tissue were determined by Western blot. Real-time quantitative polymerase chain reaction(Real-time PCR) was employed to determine the mRNA levels of GSDMD, Caspase-1, IL-1β, and IL-18. ResultCompared with the blank group, the model group showed elevated levels of ALT and AST (P<0.01) and risen levels of inflammatory cytokines in the serum (P<0.01). In addition, the modeling resulted in edema and necrosis in the liver, and up-regulated the protein levels of GSDMD, NLRP3, ASC, and Caspase-1 (P<0.01) and the mRNA levels of GSDMD, Caspase-1, IL-1β, and IL-18 (P<0.01). Compared with the model group, the drug intervention groups showed reduced content of inflammatory cytokines (P<0.01), alleviated pathological damage in the liver tissue, and down-regulated protein levels of GSDMD, NLRP3, ASC, and Caspase-1 (P<0.05,P<0.01) and mRNA levels of GSDMD, Caspase-1, IL-1β, and IL-18 (P<0.05,P<0.01) in the liver tissue. ConclusionHuanglian Jiedutang can inhibit pyroptosis and reduce inflammation by inhibiting the activation of NLRP3 inflammasomes, thus demonstrating a therapeutic effect on acute liver injury in the mouse model of sepsis induced by LPS.