BACKGROUND Salidroside, the major active compound in Rhodiola, has been reported to provide beneficial effects on cardiovascular diseases, but its effects on diabetes-induced vascular endothelial dysfunction are less known. Here, we examined the protective effects of salidroside on endothelial function in diabetes and explored the potential underlying mechanism. MATERIAL AND METHODS First, we assessed the endothelium-dependent relaxation response to acetylcholine, with or without salidroside treatment, in aortas isolated from Sprague-Dawley rats. Then, cell viability, oxidative biomarkers, and protein expression were tested to determine the effect of salidroside treatment on human umbilical vein endothelial cells (HUVECs) in vitro. RESULTS Advanced glycation end product (AGE)-induced endothelial dysfunction was significantly improved by salidroside treatment (P<0.05), as shown by a reduced relaxation response to the vasodilator acetylcholine. Further, incubation with salidroside restored NO levels and reduced reactive oxygen species formation in AGE-stimulated HUVECs in a concentration-dependent manner (P<0.05). We also showed that nuclear factor (erythroid-derived 2)-like 2 (Nrf2)/heme oxygenase 1 (HO-1) and nuclear factor kappa B (NF-κB) signaling was critical for the salidroside-mediated beneficial regulation. CONCLUSIONS Our results demonstrate that salidroside protects against AGE-induced endothelial dysfunction, and its effects may be in part attributed to the induction of HO-1 and attenuation of phosphorylated NF-κB p65.