Effect and mechanism of PNU-282987 on cognitive function of temporal lobe epilepsy model rats / 中国药房

ABSTRACT

OBJECTIVE To investigate the effect and mechanism of α7 nicotinic acetylcholine receptor （α7nAChR） agonists PNU-282987 on cognitive function in temporal lobe epilepsy （TLE） model rats. METHODS Sixty rats were randomly divided into control group， model group， PNU-282987 group （3 mg/kg） and methyllycaconitine （MLA）+PNU-282987 group （6 mg/kg MLA+3 mg/kg PNU-282987）， with 15 rats in each group. Except for control group， the TLE model was established in the other groups. After the model was successfully established， each group was given relevant medicine or normal saline intraperitoneally， once a day， for two consecutive weeks. The epilepsy attack of rats was observed and scored， and the duration of seizures was recorded； the cognitive function of rats was detected； pathological morphology of neurons in CA1 region was observed； the levels of tumor necrosis factor-α （TNF-α）， interleukin-6 （IL-6） and IL-1β in the hippocampus were detected； the positive expressions of ionized calcium-binding adapter molecule-1 （IBA-1）， α7nAChR， nuclear factor-κB （NF-κB） p65， p-NF-κB p65 in the hippocampus were detected. RESULTS Compared with model group， the score and duration of seizures， the number of IBA-1 positive cells， the levels of TNF- α， IL-6 and IL-1β， the expressions of NF- κB p65 and p-NF- κB p65 protein decreased significantly in the hippocampus （P＜0.05）； the escape latency time was shortened significantly （P＜0.05）， the time spent in the original platform quadrant and times of crossing the platform increased significantly （P＜0.05）； neuronal damage in the CA1 region of the hippocampus was significantly reduced； the expression of α7nAChR protein increased significantly in hippocampus （P＜0.05）. Compared with PNU-282987 group， the above indexes of rats in MLA+PNU-282987 group were reversed significantly （P＜0.05）. CONCLUSIONS PNU-282987 could improve cognitive dysfunction in TLE model rats， and its mechanism may be associated with inhibiting microglia-mediated inflammatory response through α7nAChR/NF- κB signaling pathway， thus reducing hippocampal neuronal damage.