[Shenzao Jiannao Oral Liquid treats Alzheimer's disease by regulating gut microbiota].

High-dose SZJN improved spatial learning and memory in APP/PS1 transgenic AD mice as measured by the Morris water maze.

• APP/PS1 double transgenic mice were used as the AD model and treated by gavage for 8 weeks
• High-dose SZJN group (7.5 g·kg⁻¹) exhibited shortened escape latency compared to the model group
• High-dose SZJN group showed increased platform crossings and increased time spent in the target quadrant
• Comparator groups included donepezil hydrochloride (0.65 mg·kg⁻¹) as positive drug and low- (0.3 g·kg⁻¹) and medium-dose (1.5 g·kg⁻¹) SZJN

High-dose SZJN improved daily living abilities in AD mice as assessed by the nesting test.

• The nesting test was used to assess daily living abilities
• High-dose SZJN group showed improved nesting scores compared to the model group
• All groups received treatment by gavage for 8 weeks
• C57BL/6J mice of the same brood served as the blank control group

High-dose SZJN alleviated intestinal histopathological damage and improved mucus barrier integrity in AD mice.

• HE staining showed alleviated intestinal mucosal contraction and improved cellular morphology in the high-dose SZJN group
• High-dose SZJN groups exhibited reduced intestinal tissue damage compared to the model group
• AB-PAS staining revealed increased mucin content and increased goblet cells in the high-dose SZJN group
• These findings indicate protection of the intestinal mucus barrier

High-dose SZJN upregulated tight junction proteins ZO-1 and Occludin while reducing intestinal macrophage marker F4/80 expression.

• Western blot was used to measure protein levels of ZO-1 and Occludin
• Immunofluorescence (IF) was used to analyze expression of ZO-1, Occludin, and the macrophage marker F4/80
• High-dose SZJN groups exhibited upregulated expression of ZO-1 and Occludin in intestinal tissue compared to model group
• High-dose SZJN groups showed reduced F4/80 protein expression, suggesting decreased intestinal macrophage infiltration or activation

High-dose SZJN increased gut microbiota species diversity and richness, with microbiota structures resembling those of the blank (healthy) group.

• Gut microbiota diversity, species abundance, and correlations were analyzed by 16S rDNA sequencing
• High-dose SZJN groups showed increased species diversity and richness compared to the model group
• Microbiota structures in the high-dose SZJN group resembled those of the blank (C57BL/6J) group
• Results suggest SZJN exerts therapeutic effects on AD at least in part through regulation of gut microbiota composition