Study on the anti‐inflammatory effect of stachyose by inhibiting TLR4/NF‐κB signalling pathway in vitro and in vivo

Abstract This study aimed to explore the anti‐inflammatory effect of stachyose, a tetrasaccharide extracted from Stachys sieboldii Miq . A lipopolysaccharide (LPS)‐stimulated RAW264.7 macrophages model and a dextran sodium sulfate (DSS)‐induced ulcerative colitis BALB/C mice model was used to assess the anti‐inflammatory effect of stachyose both in vitro and in vivo. The levels of nitric oxide (NO) and cytokines (interleukin‐1β, interleukin‐6 and tumour necrosis factor‐α) were detected using enzyme‐linked immunosorbent assay methods; moreover, haematoxylin–eosin staining was used to observe changes in intestinal morphology of mice. In addition, the possible mechanisms were explored by reverse transcription‐polymerase chain reaction and western blot. Results showed that stachyose and four other oligosaccharides (galacto‐oligosaccharides, xylo‐oligosaccharides, inulin and resistant dextrin) inhibited NO secretion and the production of pro‐inflammatory cytokines in LPS‐stimulated RAW264.7 macrophages in a dose‐dependent manner, whereas stachyose was most effective in vitro. In mice, different doses of stachyose significantly alleviated the symptoms of DSS‐induced ulcerative colitis and stachyose also significantly inhibited the production of inflammatory cytokines and myeloperoxidase in vivo. In addition, our findings illustrated that stachyose inhibited expression of toll‐like receptor 4 (TLR4) and suppressed the phosphorylation of nuclear factor (NF)‐κB p65 both in vitro and in vivo. Taken together, results demonstrated that stachyose exerted anti‐inflammatory effect through inhibition of the TLR4/NF‐κB signalling pathway.