Effects of intranasal administration of tripterygium glycoside-bearing liposomes on behavioral cognitive impairment of mice induced by central nervous system inflammation

Abstract

Tripterygium glycosides liposome(TPGL) were prepared by thin film-dispersion method, which were optimized accor-ding to their morphological structures, average particle size and encapsulation rate. The measured particle size was(137.39±2.28) nm, and the encapsulation rate was 88.33%±1.82%. The mouse model of central nervous system inflammation was established by stereotaxic injection of lipopolysaccharide(LPS). TPGL and tripterygium glycosides(TPG) were administered intranasally for 21 days. The effects of intranasal administration of TPG and TPGL on behavioral cognitive impairment of mice due to LPS-induced central ner-vous system inflammation were estimated by animal behavioral tests, hematoxylin-eosin(HE) staining of hippocampus, real-time quantitative polymerase chain reaction(RT-qPCR) and immunofluorescence. Compared with TPG, TPGL caused less damage to the nasal mucosa, olfactory bulb, liver and kidney of mice administered intranasally. The behavioral performance of treated mice was significantly improved in water maze, Y maze and nesting experiment. Neuronal cell damage was reduced, and the expression levels of inflammation and apoptosis related genes [tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β), BCL2-associated X(Bax), etc.] and glial activation markers [ionized calcium binding adaptor molecule 1(IBA1) and glial fibrillary acidic protein(GFAP)] were decreased. These results indicated that liposome technique combined with nasal delivery alleviated the toxic side effects of TPG, and also significantly ameliorated the cognitive impairment of mice induced by central nervous system inflammation.