RESUMEN
Objective:To investigate the effect of paeoniflorin on toll-like receptor 4(TLR4)/nuclear transcription factor(NF-κB) signaling pathway of streptozotocin combined with ovariectomized mice, and to explore whether it can improve the cognitive impairment of ovariectomized diabetic mice.Methods:Ninety female C57BL/6J mice were divided into SHAM group, ovariectomy group, diabetes group(intraperitoneal injection of STZ 50 mg·kg -1·d -1 for 5 consecutive days), dual model group(DM modeling and OVX operation), paeoniflorin low-dose intervention group(OVX+ STZ+ L-PF 50 mg·kg -1·d -1), paeoniflorin high-dose intervention group(OVX+ STZ+ H-PF 100 mg·kg -1·d -1; all groups n=15). After 8 weeks of paeoniflorin intervention, their cognitive function was tested by behavioral experiments(Morris water maze and Y maze). The pathological changes of hippocampal tissue were observed by HE and Nissl staining. The mRNA expressions of TLR4, tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β) and interleukin-6(IL-6) in hippocampal tissues were detected by real-time fluorescence quantitative PCR. The expression of TLR4, NF-κB P65, TNF-α, IL-6, IL-1β, β-amyloid protein(Aβ), tau proteins, and p-tau proteins were detected by Western blot. Results:Compared with SHAM group, the learning and memory ability of ovariectomy group, diabetes group and dual model group decreased, hippocampal cells were damaged, and the expression of related gene mRNA and protein were increased, especially in dual model group; Compared with dual model group, paeoniflorin intervention could delayed the learning and memory impairment, improve cognitive function, reduce the degree of hippocampal injury, and decrease the expression levels of related gene mRNA and protein, The above changes were the most pronounced at paeoniflorin high-dose intervention group.Conclusion:Paeoniflorin improves cognitive dysfunction in ovariectomized diabetic mice by inhibiting TLR4/NF-κB signaling pathway.