Objective To explore the effect of mangiferin (MF) on pyroptosis in an amyotrophic lateral sclerosis (ALS) cell model by regulating the nuclear factor erythroid 2-related factor 2/heme oxygenase-1 (Nrf2/HO-1) signaling pathway. Methods (1)Mouse NSC-34 cell lines transfected with hSOD1^WT and hSOD1^G93A plasmids were randomly divided into blank group, model group, MF (100 μmol/L) group, MF (200 μmol/L) group. MF was added into the culture plate for 24 hours. Cell viability was assessed using CCK-8 kit. Lactate dehydrogenase (LDH) release was measured using LDH cytotoxicity detection kit. Levels of inflammatory factors interleukin (IL)-1β and IL-18 in cell supernatant were determined by enzyme-linked immunosorbent assay (ELISA). The expression of Nrf2, HO-1, NADPH quinone oxidoreductase-1 (NQO-1), NOD-like receptor protein 3 (NLRP3), gasdermin D (GSDMD)-N and caspase-1 was detected by Western blotting. (2)Mouse hSOD1^G93A NSC-34 cells were randomly divided into model group, MF(200 μmol/L) group, Nrf2-siRNA group and Nrf2-siRNA+MF(200 μmol/L) group. The cells were transiently transfected with Nrf2-siRNA using Lipofectamine^TM 3000. Western blotting was used to detect the protein expression levels of Nrf2, HO-1, NQO-1, NLRP3, caspase-1 and GSDMD-N. Results (1) The results of the CCK-8 assay showed that after the hSOD1^G93A NSC-34 cells were treated with MF at concentrations of 300 μmol/L and below for 24 hours, the changes in cell viability were not significant (P>0.05). Compared with blank group, the release of LDH, the contents of IL-1β and IL-18 in the cell culture supernatant of model group were increased (P<0.001); the protein expression levels of Nrf2, HO-1, and NQO-1 were decreased (P<0.05 or P<0.01); the protein expression levels of NLRP3, caspase-1, and GSDMD-N were increased (P<0.05 or P<0.01 or P<0.001). Compared with model group, the release of LDH, the contents of IL-18 and IL-1β in the culture supernatant in MF(100 μmol/L) and MF(200 μmol/L) groups were decreased (P<0.001); the protein expression levels of NLRP3, caspase-1 and GSDMD-N were decreased (P<0.05 or P<0.001), and the expression levels of Nrf2, HO-1 and NQO-1 were increased (P<0.05 or P<0.01). (2) Compared with model group, the protein expession levels of Nrf2, NO-1 and NQO-1 were increased (P<0.05 or P<0.001) in MF(200 μmol/L) group, while the protein expression levels of NLRP3, caspase-1 and GSDMD-N were decreased (P<0.001); the protein expression levels of Nrf2 and HO-1 were decreased in Nrf2-siRNA group (P<0.01 or P<0.001), while the protein expression levels of NLRP3, caspase-1 and GSDMD-N were increased (P<0.001). Compared with Nrf2-siRNA group, the protein expression levels of Nrf2, HO-1 and NQO-1 in Nrf2-siRNA+MF(200 μmol/L) group were increased (P<0.01 or P<0.001), and the protein expression levels of NLRP3, caspase-1 and GSDMD-N were decreased (P<0.001). Conclusion MF can inhibit pyroptosis in the ALS cell model through Nrf2/HO-1 signaling pathway, playing a protective role.