Polysaccharides of Melientha longistaminea regulates immune function and gut microbiota in cyclophosphamide (CTX)-induced immunosuppressed mice

MLS is a bioactive extract of Melientha longistaminea shoots. In this study, we characterized the preliminary structure of MLS. And establish in vivo immune model experiments. To investigate the potential mechanism of immunomodulatory effects on CTX-induced immunosuppressed mice. From the experimental results, we found that MLS restored immune organ damage in immunosuppressed mice, increased cytokine and immunoglobulin secretion in the spleen, and attenuated oxidative damage to the liver by CTX. Meanwhile, MLS was also effective in ameliorating immune injury in immunosuppressed mice by activating the NF-κB and Nrf2 signaling pathways. MLS effectively improved the composition of the gut flora and increased the production of SCFAs in the gut. The results indicate that MLS has immunomodulatory effects and provides a research basis for developing Melientha longistaminea polysaccharides as immunomodulatory adjuvants.