ObjectiveTo observe the effect of Huangqi Baihe granules on the hypoxia-inducible factor 1α （HIF-1α）/nuclear factor-κB （NF-κB）/NOD-like receptor hot protein domain related protein 3 （NLRP3） signaling pathway in a rat model of high altitude hypoxia. MethodSixty male SPF SD rats were randomly divided into blank group， model group， dexamethasone group （5 mg·kg^-1）， and high， middle， and low-dose groups of Huangqi Baihe granules （4.1， 2.05， 1.025 g·kg^-1）. Among them， each Chinese medicine group was administrated orally for continuously 14 d， once a day， and the dexamethasone group was injected intraperitoneally for continuously 3 d as the positive control group. On the 15^th d， the model group， dexamethasone group， and high， middle， and low dose groups of Huangqi Baihe granules were exposed to the simulated high altitude， low pressure， and low oxygen environment in the animal low-pressure simulation cabin， and the exposure lasted for 3 d. Blood was collected from the abdominal aorta and serum was separated， and the brain tissue was taken after being killed. Hematoxylin-eosin （HE） staining was used to observe the pathological changes in brain tissue. Enzyme-linked immunosorbent assay （ELISA） was used to detect the content of tumor necrosis factor-α （TNF-α）， interleukin-6 （IL-6）， and interleukin-1β （IL-1β） in rat serum. Western blot was used to detect HIF-1α， NLRP3， phosphorylated nuclear factor-κB （p-NF-κB）， NF-κB， desquamation D （GSDMD）， and cysteine aspartate-specitis protein-1（Caspase-1） in rats of each group. The mRNA expression levels of HIF-1α， NLRP3， NF-κB p65， GSDMD， and Caspase-1 were detected by real-time quantitative polymerase chain reaction （Real-time PCR）. ResultThe results of HE staining showed that as compared with the normal group， the pathological sections of brain tissues in the model group showed that pyramidal cells were loosely arranged and distributed in disorder， with different sizes. Compared with the model group， the pathological changes in pyramidal cells in the dexamethasone group and high and middle-dose groups of Huangqi Baihe granules were reduced. The results of ELISA showed that as compared with the normal group， the content of TNF-α， IL-6， and IL-1β in the serum of rats in the model group was significantly higher （P<0.01）. Compared with the model group， the content of TNF-α， IL-6， and IL-1β in the serum of rats in the dexamethasone group and high and middle-dose groups of Huangqi Baihe granules decreased significantly （P<0.05， P<0.01）. The results of Western blot showed that as compared with the normal group， the relative protein expression levels of HIF-1α， NLRP3， p-NF-κB p65， GSDMD， and Caspase-1 in the brain tissue of the model group were significantly higher （P<0.01）. As compared with the model group， the relative expressions of HIF-1α， NLRP3， p-NF-κB p65， GSDMD， and Caspase-1 in the brain tissue of rats in the dexamethasone group and the high-dose group of Huangqi Baihe granules were significantly decreased （P<0.05， P<0.01）. The relative protein expression levels of HIF-1α， NLRP3， p-NF-κB p65， and Caspase-1 in the brain tissue of rats in the middle-dose group of Huangqi Baihe granules decreased significantly （P<0.01）， and the relative protein expression of HIF-1α in the brain tissue of rats in the low-dose group of Huangqi Baihe granules was reduced （P<0.05）. The Real-time PCR analysis showed that as compared with the normal group， the mRNA expression levels of HIF-1α， NLRP3， NF-κB p65， GSDMD， and Caspase-1 in the brain tissue of the model group were significantly increased （P<0.01）. As compared with the model group， the mRNA expression levels of HIF-1α， NLRP3， NF-κB p65， GSDMD， and Caspase-1 in the brain tissue of rats in the dexamethasone group were significantly decreased （P<0.01）. The mRNA expression levels of HIF-1α， NF-κB p65， GSDMD， and Caspase-1 in the brain tissue of rats in the high-dose group of Huangqi Baihe granules decreased significantly （P<0.01）. The mRNA expression levels of HIF-1α， NLRP3， and Caspase-1in the brain tissue of rats in the middle-dose group of Huangqi granules decreased （P<0.05， P<0.01）. ConclusionThe protective effect of Huangqi Baihe granules on acute brain injury in low-pressure hypoxic rats may be related to the HIF-1α/NF-κB/NLRP3 signaling pathway.