Abstract： Objective To investigate the effect and mechanism of Liraglutide on the spatial learning and memory function in type 2 diabetes mellitus(T2DM)rats.Methods SD rats were randomly divided into control group(NC),T2DM group(T2DM)and Liraglutide group(Lir).The ability of learning and memory was evaluated by Morris water maze method.Apoptosis of hippocampal neuron was tested by TUNEL staining.The mRNA expression levels of inflammatory cytokines TNF-α,IL-1β and IL-6 were measured by real time-PCR.The protein expressions of heme oxygenase-1(HO-1),NADPH oxidase 1(NOX1),protein B-cell lymphoma-2(Bcl-2)and Bcl2-associated X(Bax)in hippocampus tissues were determined by Western blot.Results Compared with T2DM group,the percent time in target quadrant was increased in Lir group(P<0.05),while the escape latency of day 3 to day 5 was significantly decreased in Lir group(P<0.05).The apoptosis of hippocampal neurons was reduced in Lir group,and the morphological changes,including hyperchromatic cytoplasm and karyopyknosis were alleviated.Compared with T2DM group,MDA content,mRNA level of TNF-α,IL-1β and IL-6,and protein expression of NOX1 and Bax were decreased(P<0.05),while T-AOC,SOD,HO-1 and Bcl-2 protein expression were increased in Lir group(P<0.05).Conclusions Liraglutide ameliorates diabetes-related learning and memory impairment by regulating antioxidant,anti-inflammatory and anti-apoptotic effects in hippocampus.