OBJECTIVETo observe the effect of Scutellarin (Scu) on expressions of nicotinic acetylcholine receptor (nAChR) subunit protein and mRNA in dementia rats, and to study its possible mechanism on dementia.

METHODSForty-two Wistar rats were randomly divided into 5 groups, i.e., the normal control group (n=6), the sham-operative group (n=6), the memory deficit model group, the Scu treatment group (n=10), and the positive drug (piracetam) control group (n=10). The dementia rat model was established by bilateral ventricle injection with beta-amyloid peptide (Abeta)(25-35) and abdominal cavity injection with D-galactose. Rats in the Scu treatment group or the piracetam control group were treated with Scu or piracetam by gastrogavage. The learning and memory ability of rats were detected by Morris water maze test, nAChR alpha4, alpha7, and beta2 subunits at protein and mRNA levels were detected by Western blot and Real-time PCR respectively.

RESULTSCompared with the normal control group and the sham-operative group, the learning and memory ability decreased in rats of the model group (P<0.05). nAChR alpha4 and alpha7 subunit protein expressions were obviously lowered (P<0.05), but changes of beta2 were not obvious. No obvious change of mRNA expressions in all three nAChR subunits was seen (P>0.05). After treatment of Scu, the learning and memory ability was greatly improved, nAChRs alpha4 and alpha7 subunit protein expressions increased in rats with dementia (all P<0.05). No obvious change of mRNA expressions in all three nAChR subunits was seen (P>0.05). No obvious difference of each index was shown between the Scu treatment group and the positive drug (piracetam) control group.

CONCLUSIONSScutellarin could improve the learning and memory ability of dementia rats. Its mechanism might be associated with its up-regulation of nAChR expressions.