Apoptosis of osteoblasts plays a crucial role in osteomyelitis. Hydrogen sulfide (H2S) levels are increased in the pathophysiological processes of osteomyelitis. However, the effect of H2S on the apoptosis of osteoblasts remains unclear. To investigate the specific role of H2S in osteoblast apoptosis, MC3T3-E1 and hFOB cells were treated with NaHS or Na2S, a donor of H2S, and lipopolysaccharide (LPS), during osteomyelitis. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays, flow cytometry analysis, western blotting, immunofluorescence, polymerase chain reaction, and Alizarin red staining were performed to examine the effects of H2S on osteoblast cell apoptosis, cell osteogenic differentiation, and AKT kinase (AKT)/nuclear factor kappa B (NF-kappa B) signaling. Hydrogen sulfide increased cell apoptosis, and inhibited the proliferation and osteogenic differentiation of osteoblast cells impaired by LPS. H2S increased apoptosis through upregulation of the FAS ligand (FASL) signaling pathway. H2S-induced apoptosis was alleviated using a FAS/FASL signaling pathway inhibitor. Treatment with NaHS also increased cell apoptosis by downregulating AKT/NF-kappa B signaling. In addition, treatment with an AKT signaling pathway activator decreased apoptosis and reversed the inhibitory effects of H2S on osteogenic differentiation. Hydrogen sulfide promotes LPS-induced apoptosis of osteoblast cells by inhibiting AKT/NF-kappa B signaling. (C) 2020 Elsevier Inc. All rights reserved.