Zhinao Capsule improves learning and memory impairment in APP/PS1 mice through gut-brain axis-mediated inhibition of neuroinflammation

Traditional Chinese Medicine (TCM) interventions have attracted increasing attention in recent years, with a growing body of evidence supporting their efficacy in the treatment of Alzheimer's disease (AD). Zhinao Capsule (ZNJN), a proprietary TCM formulation, has demonstrated promising clinical outcomes, particularly in enhancing cognitive function and alleviating AD-related pathology in rodent models. This study aimed to evaluate the neuroprotective effects of ZNJN in APP/PS1 transgenic mice. Behavioral assessments indicated that ZNJN, especially at the high dose, significantly improved learning and memory abilities. Histopathological analysis revealed a marked reduction in hippocampal Aβ_1-42 deposition and decreased activation of microglia and astrocytes, as evidenced by lower expression levels of Iba-1 and GFAP. In addition to central effects, ZNJN alleviated colonic inflammation and improved mucosal integrity. Systemic inflammatory responses were also suppressed, with significant reductions in serum levels of TNF-α, IL-6, IL-1β, and LPS. Furthermore, 16S rRNA gene sequencing showed that ZNJN modulated the gut microbiota by decreasing the abundance of pro-inflammatory genera and enriching potentially beneficial. These findings suggest that ZNJN exerts neuroprotective effects by modulating the gut microbiota and reducing neuroinflammation through the gut-brain axis. These findings suggest that ZNJN exerts neuroprotective effects by modulating the gut microbiota and reducing neuroinflammation through the gut-brain axis. This study provides experimental evidence supporting the potential of ZNJN as a multi-target therapeutic agent for AD intervention.