Abstract: Objective To investigate the role of caspase- 1 activation in bilirubin- induced neuronal injury and the protective effect of VX- 765 against bilirubin- induced neurotoxicity in cultured primary rat hippocampal neurons. Methods Cultured primary rat hippocampal neurons were exposed to DMSO (control group), 50 μmol/L bilirubin, or 50 μmol/L bilirubin 1 h after 50 μmol/L VX-765 treatment. The expressions of NLRP3 and caspase-1 in the neurons were detected by Western blotting, and the relative cell survival and death rates were assessed with a modified MTT assay, lactate dehydrogenase assay and Typan blue staining. Interleukin-18 (IL-18) concentration in the culture supernatant was measured using enzyme-linked immunosorbent assay (ELISA). Results In cultured primary rat hippocampal neurons, bilirubin exposure for 3 and 6 h caused significant increases in the expressions of NLRP3 and activated caspase-1 compared with those in the control group (P<0.05). Pretreatment of the cells with VX-765 obviously suppressed bilirubin- induced activation of caspase- 1 (P<0.05). The relative survival rate of the neurons was (84.02±2.31)% in VX-765 intervention group, significantly higher than that in bilirubin group (P<0.05) but lower than that in the control group (P<0.05); LDH release rate in VX-765 intervention group was (10.78±1.58)%, significantly lower than that in bilirubin group (P<0.05) but higher than that in the control group (P<0.05). The cell death rate in VX-765 intervention group was (5.58±1.23)%, significantly lower than that in bilirubin group (P<0.05) but higher than that in the control group (P<0.05). Conclusion In cultured primary rat hippocampal neurons, caspase- 1 activation plays a role in bilirubin- induced neurotoxicity, and VX-765 treatment provides protection against bilirubin- induced neuronal injury by inhibiting caspase-1 activation.