Abstract: ObjectiveTo explore the effects of docosahexaenoic acid(DHA)on neurotrophic growth factors(NFG), brain derived neurotrophic factor(BDNF),apolipoprotein E(APOE),and apolipoprotein J(APOJ)in olfactory bulb of aged rat.MethodsSprague-Dawley(SD)rats of 24 months were treated with 180,360 mg/kg·d of DHA via oral gavage for 49 days.The rats were killed and the olfactory bulb was collected.NGF,BDNF levels were determined with enzym-linked immunosorbent assay(ELISA)and western blotting method was used to assay APOE and APOJ protein levels.ResultsDHA supplementation increased the levels of NGF(11.17±1.27 pg/mg for 180 mg/kg DHA group,12.48±2.35 pg/mg for 360 mg/kg DHA group)with the increases of 36.05% and 52.01%,respectively,compared with those of the aged group (8.21±1.17 pg/mg).The levels of BDNF(28.23±2.74 pg/mg for 180 mg/kg DHA group,30.76±2.71 pg/mg for 360 mg/kg DHA group)increased by 17.45% and 28.01%,respectively,compared with those of the aged rat.DHA also increased APOJ protein level and decreased APOE protein level in olfactory bulb of the aged rat,compared with those of the control group significantly.ConclusionDocosahexaenoic acid has a protective effect on olfactory bulb of aged rat.