Aim To investigate the effects and possible molecular mechanisms of dioscin(DIO)against depression in mice.Methods Eighty mice were randomly divided into control group, DIO control group, model group, DIO groups(20, 40 and 80 mg·kg-1 DIO)and FLU group(20 mg·kg-1 fluoxetine).After establishing the depression model with chronic unpredictable moderate stress(CUMS)in mice, the corresponding drugs were administered by gavage continuously for four weeks in each group.The behavior of mice was tested, and the contents of corticosterone(CORT), brain-derived neurotrophic factor(BDNF), 5-hydroxytryptamine(5-HT), malondialdehyde(MDA), superoxide dismutase(SOD)and catalase(CAT)were evaluated by ELISA or enzyme labeling method.In addition, HE staining, Nissl staining and PET scanning were operated for the brain tissues.Western blot was used to detect the protein expressions.Results Compared with model group, DIO significantly improved the behaviors of depressed mice.And it reduced the contents of CORT in serum, increased BDNF and 5-HT in hippocampus.Meanwhile, DIO obviously reduced MDA in serum, increased SOD in serum and CAT in brain tissues.DIO improved the steatosis of brain tissues, disorder and looseness of neurons, and increased glucose metabolism in brain tissues of depressed mice.The molecular mechanism suggested that compared with model group, DIO significantly increased the protein level of UCP2 to adjust the levels of Nrf2, SOD2, GLUT1 and G6Pase.Conclusions DIO improves the depression symptoms of depressed mice, which should be through adjusting UCP2-mediated oxidative stress and glucose metabolism.