Fig. 3

Asperosaponin VI switches activated microglia from a pro-inflammatory to anti-inflammatory phenotype in hippocampus of CMS mice. A Levels of mRNAs encoding Arg-1 and iNOS in hippocampus and cortex of Ctrl or CMS mice after treatment with saline or ASA VI. B Ratio of the levels of mRNAs encoding Arg-1 to iNOS in hippocampus and cortex of Ctrl or CMS mice after treatment with saline or ASA VI. C Fluorescence micrographs of anti-inflammatory microglia (Arg-1⁺-Iba1⁺ cells) in hippocampus of CMS mice after treatment with ASA VI. Anti-inflammatory marker was stained with an antibody against Arg-1 (green); microglia, with an antibody against Iba1 (red); and nuclei, with DAPI (blue). The cells positive for Arg-1 and Iba1 were considered anti-inflammatory microglia. Histogram is quantification of the percentage of Arg-1⁺-Iba1⁺ cells. Scale bar, 10 μm. D Fluorescence micrographs of pro-inflammatory microglia (iNOS⁺-Iba1⁺ cells) in hippocampus of CMS mice. Pro-inflammatory cytokines were stained with an antibody against iNOS (green). The cells positive for iNOS and Iba1 were considered pro-inflammatory microglia. Histogram is the quantification of the percentage of iNOS⁺-Iba1⁺ cells. Scale bar, 10 μm. E Ratio of Arg-1⁺ microglia to iNOS⁺ microglia in hippocampus and cortex of Ctrl or CMS mice after treatment with saline or ASA VI. F Schematic illustrating how ASA VI switches activated microglia from a pro-inflammatory to anti-inflammatory phenotype in hippocampus of CMS mice. G Correlation of the ratio of Arg-1⁺ microglia to iNOS⁺ microglia in hippocampus or cortex of each group mice with sucrose preference and latency and immobility time in the FST. H Levels of mRNAs encoding the pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) and the anti-inflammatory cytokines (IL-10 and TGF-β) and brain-derived neurotrophic factor (BDNF) in hippocampus and cortex of Ctrl or CMS mice after treatment with saline or ASA VI. I Levels of IL-1β, IL-10 and BDNF in hippocampus and cortex of Ctrl or CMS mice after treatment with saline or ASA VI. Data for individual animals are displayed (mean ± SEM, n = 3–5), A, C–E and I *p < 0.05, **p < 0.01, ***p < 0.001. B and H *p < 0.05, *p < 0.01, ***p < 0.001 vs. Ctrl group, ^#p < 0.05, ^##p < 0.01, ^###p < 0.001 vs. CMS group (two-way ANOVA with Tukey's multiple-comparisons test)