Aims: Humanin (HN) is known for its anti-apoptotic functions in neuronal cells. In this study, we sought to investigate the protective effect of [Gly14]-Humanin (HNG) in high glucose (HG)-induced apoptosis of human umbilical vein endothelial cells (HUVECs). Methods: 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to examine cell viability, DNA chromatin morphology was assessed using Hoechst 33342 staining, and the generation of intracellular reactive oxygen species (ROS) was assessed using the fluorescent probe dichlorofluorescein diacetate (DCFH-DA). The expression of poly ADP-ribose polymerase (PARP), the pro-apoptotic protein bax and the antiapoptotic protein bcl-2 were examined using western blot analysis. The mRNA level of bax and bcl-2 were detected by quantitative Real-Time PCR. Results: Compared with treatment with HG 72 h, pretreatment with HNG for 3 h significantly increased cell viability (P < 0.001), reduced nuclear fluorescence of HUVECs (P < 0.05), the levels of cleaved PARP (P < 0.05), ROS formation (P < 0.05) and the ratio of bax/bcl-2 (P < 0.05) compared with treatment with HG for 72 h. Quantitative Real-Time PCR showed that mRNA level of bax reduced (P < 0.05) and mRNA level of bcl-2 increased (P < 0.05) after pretreatment with HNG. Conclusions: Our results imply that HNG can protect HUVECs from apoptosis induced by HG through the bax/bcl-2 pathway. (C) 2014 Elsevier Ireland Ltd. All rights reserved.