OBJECTIVETo investigate the influence of Qingkailing (QKL) on learning and memory abilities, global neurotransmitter and phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathway of senescence accelerated mouse-prone/8 (SAMP8) mice with Alzheimer's dementia (AD).

METHODSSAMP mice were modeled and divided into the model group, the QKL group and the doneppezil hydrochloride group, all treated for 90 days. And a control group was set up with senescence accelerated mouse-resistance/1 (SAMR1) mice. Morris water maze was used to test the learning and memory abilities of mice; contents of acetylcholine (Ach) and monoamine neurotransmitters in brain were measured by HPLC; levels of Grb2-associated binder-1 (Gab1), AKT and phospho-serine/threonine protein kinase B (PAKT473) were evaluated by Western-blot.

RESULTSCompared with the control group, in the model group, the average escape latency detected by hidden platform trial and reverse trial on the 3rd day was higher (P < 0.01); levels of Ach, 5-hydroxytryptamine (5-HT) and Gab1 were lower (P < 0.01, P < 0.05 and P < 0.01), respectively. As compared with the model group, the escape latency (within the 2nd to 5th day) decreased (P < 0.01), levels of Ach and 5-HT increased (P < 0.05), and Gab1 protein expression increased (P < 0.01) in the QKL treated group after treatment, in addition, the level of phosphorylated AKT protein significantly increased (P < 0.05).

CONCLUSIONQKL could improve the learning and memory ability of AD model mice, which is probably related to its function in increasing cerebral Ach, 5-HT and activating PI3K/AKT pathway.