Suanzaoren Tang may alleviate insomnia by balancing neurotransmitters, and suppressing inflammation and oxidative stress, possibly through gut microbiota-metabolite-brain axis modulation and glial cell activity restoration.
An integrated multi-omics approach was employed, starting with UPLC-ESI-MS/MS analysis to identify the compounds present in Suanzaoren Tang (SZRT). The study induced insomnia in rats by intraperitoneal administration of p-chlorophenylalanine (PCPA). Behavioral evaluations were conducted to judge sleep quality, alongside ELISA and immunofluorescence procedures to detect changes in neurotransmitter and inflammatory marker levels, respectively. Further methodologies included untargeted metabolomics and 16S rRNA sequencing to elucidate SZRT's effect on gut microbiota composition and various metabolic pathways.
The study found that treatment using PCPA significantly extended sleep latency and altered neurochemical profiles of the subjects, demonstrated through decreased levels of neurotransmitters γ-aminobutyric acid and 5-hydroxytryptamine, and increased levels of glutamate, interleukin-6, tumor necrosis factor-α, and CYP2E1 expression. Immunofluorescence further revealed reduced glial cell function and associated serotonergic dysregulation in the PCPA group. The intervention of SZRT, however, reversed these changes. In addition, PCPA was found to disrupt gut microbial composition, the adverse effects of which were remedied by SZRT administration. Through metabolomics, the study identified key differentiated metabolites that hinted at SZRT's restoration of neurotransmitter homeostasis and reduced inflammation through microbiota-metabolite interactions.
