[Mechanism of total flavone of Abelmoschus manihot in treating ulcerative colitis and depression via intestinal flora-glycerophospholipid metabolism- macrophage polarization pathway].

This study delves into the mechanism of total flavone of Abelmoschus manihot(TFA) in treating ulcerative colitis(UC) and depression via inhibiting M1 polarization of macrophages and reshaping intestinal flora and glycerolphospholipid metabolism. The study established a mouse model of UC and depression induced by chronic restraint stress(CRS) and dextran sulfate sodium(DSS). The fecal microbiota transplantation(FMT) experiment after TFA intervention was conducted. Mice in the FMT donor group were modeled and treated, and fecal samples were taken to prepare the bacterial solution. Mice in the FMT receptor group were treated with antibiotic intervention, and then administered bacterial solution by gavage from mice in the donor group, followed by UC depression modeling. After the experiment, behavioral tests were conducted to evaluate depressive-like behaviors by measuring the levels of 5-hydroxytryptamine(5-HT) and brain-derived neurotrophic factor(BDNF) in the hippocampus of mice. The levels of tumor necrosis factor-α(TNF-α),interleukin-6(IL-6),and interleukin-1β(IL-1β)in the brain and colon tissue of mice were also measured, and the polarization status of macrophages was evaluated by measuring the mRNA levels of CD86 and CD206. 16S ribosomal RNA(16S rRNA) sequencing technology was used to analyze changes in the intestinal flora of mice. Wide target lipidomics was used to detect serum lipid metabolite levels in mice after FMT,and correlation analysis was conducted between lipids and differential intestinal flora significantly regulated by TFA. In vitro experiments, representative glycerophospholipid metabolites and glycerophospholipid inhibitors were used to intervene in Raw264.7 macrophages, and the mRNA levels of TNF-α,IL-6,IL-1β,CD86,and CD206 were detected. The results showed that TFA and FMT after intervention could significantly improve depressive-like behavior and intestinal inflammation in mice with UC and depression, significantly downregulate pro-inflammatory cytokines and CD86 mRNA expression in brain and colon tissue, inhibiting M1 polarization of macrophages, and significantly upregulate CD206 mRNA expression, promoting M2 polarization of macrophages. In addition, the high-dose group had a more significant effect. After TFA intervention, FMT significantly corrected the metabolic disorder of glycerophospholipids in mice with UC and depression, and there was a significant correlation between differential intestinal flora and glycerophospholipids. In vitro experiments showed that glycerophospholipid metabolites, especially lysophosphatidylcholine(LPC),significantly upregulated pro-inflammatory cytokines and CD86 mRNA expression, promote M1 polarization of macrophages, while glycerophospholipid inhibitors had the opposite effect. The results indicate that TFA effectively treats depression and UC by correcting intestinal flora dysbiosis and reshaping glycerophospholipid metabolism, thereby inhibiting M1 polarization of macrophages.