Bee pollen consists of floral pollen mixed with bee secretions and
nectar. It has been considered as a functional food and has different kinds of biologically active ingredients, such as
flavonoids,
polyphenols,
phytosterols and minerals. However, its function in cognition has yet been investigated. In the present study, we investigated the ameliorating effect of bee pollen against
scopolamine-caused
cognitive impairment through the passive avoidance test, the Y-maze test and the Morris water maze test. In addition, Western blotting was employed to verify the effects of bee pollen on memory-related signaling molecules in the hippocampus.
Bee pollen extract (100 or 300 mg/kg, per os (p.o.)) obviously reversed
scopolamine-caused
cognitive impairment in the passive avoidance test, ameliorated spontaneous alternation versus the
scopolamine-treated group in the Y-maze test and prolonged swimming time in the target zone in the Morris water maze test. In addition, the phosphorylation levels of
extracellular signal-regulated kinase (ERK),
cAMP response element-binding protein (
CREB), protein kinase B (Akt) and
glycogen synthase kinase-3β (GSK-3β), and the expression levels of
brain-derived neurotrophic factor (
BDNF) and
tissue plasminogen activator (tPA) in the hippocampi, were increased in response to the treatment with
bee pollen extract (100 or 300 mg/kg, p.o.). These results indicated that bee pollen ameliorates
cognitive impairment induced by
cholinergic blockade through the enhancing conversion of proBDNF to mature
BDNF by tPA, probably, through the ERK-CREB pathway or Akt-GSK-3β signaling pathway and would be a useful agent for the treatment of
cognitive dysfunction.