The anti-amnesic effects of luteolin against amyloid β_25-35 peptide-induced toxicity in mice involve the protection of neurovascular unit

Luteolin (3′,4′,5,7-tetrahydroxyflavone) is an important member of the flavonoid family. It exhibits strongly anti-inflammatory, antioxidant and phytoestrogen-like activities. In the present study, we examined the anti-amnesic and protective effects of luteolin against Aβ_25-35-induced toxicity in mice. Mice were given an i.c.v. injection of aggregated Aβ_25-35 peptide. The learning and memory impairments, ultrastructural changes of cerebral cortex, cerebrovascular dysfunction and neuronal changes were detected after oral administration of luteolin continuously for 8 days. Our results demonstrate that oral administration of luteolin for 8 days for those Aβ_25-35-induced amnesic mice conferred robust neurovascular protection in Aβ_25-35-induced amnesia, involving the improvement of the spatial learning and memory capabilities, the modulation of microvascular function, the increase of regional cerebral blood flow values, the clearance of reactive oxygen species, the improvement of cholinergic neuronal system, and the increase of brain-derived neurotrophic factor level and its receptor tyrosine kinase B expression in cerebral cortex.