Compound Gaoziban tablet alleviates depression toll-like receptor 4/myeloid differentiation factor 88/nuclear factor-kappa B pathway.

OBJECTIVE
To evaluate the effect of compound Gaoziban tablet (, CGZBT) on depression, and to investigate the underlying mechanism.


METHODS
The components of CGZBT were analysed by high-performance liquid chromatography. Then, we assessed the effects of varying doses of CGZBT on an established chronic unpredictable mild stress (CUMS) model in rats. Whether animals were depressed was evaluated by sucrose preference test, open field test and forced swimming test. Neurotransmitters of hippocampus were detected by liquid chromatography-mass spec-trometry. Serum levels of tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β, IL-6, IL-4, and IL-10 were measured by enzyme-linked immunosorbent assay. Expressions of toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), phospho-nuclear factor-kappa B (p-NF-κB), cyclooxygenase-2 (COX-2), ionized calcium binding adapter molecule-1 (IBA-1) were assessed by immunohistochemical staining and western blotting.


RESULTS
Eight compounds were identified from CGZBT, moreover, our results showed that CGZBT effectively reversed the CUMS-induced decrease in sucrose preference, shortened the movement distance and prolonged immobility time. CGZBT significantly increased levels of 5-hydroxytryptamine, dopamine, norepinephrine, 5-hydroxyindoleacetic acid levels, and reduced the expression of TNF-α, IL-1β, IL-6, yet increased IL-4 and IL-10. Furthermore, the expressions of TLR4, MyD88, COX-2, p-NF-κB and IBA-1 in hippocampus were effectively reversed after treatment with CGZBT.


CONCLUSIONS
These results indicated that CGZBT could, at least in part, alleviate depression induced by CUMS the TLR4/MyD88/NF-κB pathway, suggesting its potential as an antidepressant drug.