Therapeutic effects of inulin-type oligosaccharides of Morinda officinalis on Streptococcus pneumoniae meningitis in mice
LI Zehan
LIANG Meng
HAN Gencheng
ZHANG Xuewu
Abstract：Objective To investigate the therapeutic effects of inulin-type oligosaccharides of Morinda officinalis(IOMO)in a murine model of Streptococcus pneumoniae meningitis(SPM)and explore its possible mechanisms.Methods A total of 120 male C57BL/6J mice were randomly assigned into Sham,SPM+Saline,SPM+IOMO(25 mg/kg),and SPM+IOMO(50 mg/kg)groups.After modeling,the mice received daily gavage of saline or IOMO at the indicated doses for 7 consecutive days,and the changes in symptom scores and mortality of the mice were monitored.Brain pathology and neuronal injury of the mice were assessed using HE and Nissl staining,and qRT-PCR was performed to detect mRNA levels of the inflammatory mediators.Brain edema and blood-brain barrier(BBB)permeability of the mice were evaluated by measuring brain water content and Evans blue(EB)staining;Western blotting was used to analyze the expressions of BBB-associated proteins,and flow cytometry was employed to detect IFN-γ expression level in the infiltrating lymphocytes.Open-field test(OFT)and novel object recognition test(NORT)were conducted to assess learning and memory ability of the mice on day 21 after modeling.Results IOMO treatment at 50 mg/kg significantly reduced the symptom scores and mortality rate of SPM mice,alleviated brain damage,and downregulated mRNA levels of IL-6,TNF-α,IL-1β,IL-18,IFN-γ,iNOS,NLRP3,ASC,caspase-1 and GSDMD in the brain tissue.IOMO treatment also decreased brain water content and EB leakage,upregulated VE-cadherin and occludin expressions,and suppressed AQP4,iNOS,and IFN-γ levels of the mice.IOMO-treated mice exhibited improved learning and memory compared with the saline-treated mice on day 21 after SPM modeling.Conclusion IOMO alleviates SPM symptoms,reduces mortality,and mitigates cognitive deficits in mice possibly by suppressing cerebral inflammation and protecting BBB functions.
Keywords：inulin-type oligosaccharides of Morinda officinalismeningitisStreptococcus pneumoniaeblood-brain barrierinterferon-γ
Publication Date：2025-03-20
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：10( 577-586 )