Kaempferide prevents cognitive decline via attenuation of oxidative stress and enhancement of brain-derived neurotrophic factor/tropomyosin receptor kinase B/cAMP response element-binding signaling pathway

Kaempferide (KF) is a compound of flavonoids from Alpinae oxyphylla Miq, and the herb itself is used as a classical tonic agent. This paper aims to investigate the effects of KF on cognitive function impairment and neurodegeneration in the mouse model of Alzheimer's disease induced by intracerebroventricular (ICV) injection of A beta(1-42). The mice were treated with KF at doses of 0.02 and 0.2mg/kg/day (ICV) for five consecutive days after A beta(1-42) exposures. The behavioral test results showed that KF could prevent cognitive decline in mice induced by A beta(1-42) as assessed by the locomotor activity test, Y-maze test, and Morris water maze test. Furthermore, the activities of superoxide dismutase and malondialdehyde in the hippocampus and cerebral cortex were elevated by KF administration. Results of hippocampus slices showed that neurons were integrated and regularly arranged in the groups, which were administered along with KF. In addition, we found KF could boost brain-derived neurotrophic factor (BDNF)/tropomyosin receptor kinase B (TrkB)/cAMP response element-binding (CREB) protein signal in the hippocampus. All results illustrated that KF could exert neuroprotective effects at least partly through alleviating oxidative stress and enhancing the BDNF/TrkB/CREB pathway in A beta(1-42)-induced mice.