Flammulina velutipes polysaccharides exhibit potent antioxidant and anti-pyroptotic properties in diabetes-associated periodontitis: A preliminary in vitro study

Background/purpose

Diabetes-associated periodontitis (DAP) is a complicated illness characterized by elevated oxidative stress and a pro-inflammatory response. There is a bidirectional relationship between diabetes and periodontitis. Although Flammulina velutipes polysaccharides (FVP) has demonstrated anti-inflammatory properties, its specific role in DAP remains uncertain. The purpose of our study was to seek the protective effects and the underlying mechanism of FVP against advanced glycation end products (AGEs) and lipopolysaccharide (LPS)-induced damage in human gingival fibroblasts (HGFs).

Materials and methods

Our study used HGFs treated with AGEs and LPS to mimic the in vitro environment of DAP. MTT assay was utilized to seek the various concentrations of FVP (a component of Flammulina velutipes) affected cell survival, migration, reactive oxygen species (ROS) generation, and cell senescence. Western blotting was used to evaluate the expression of pyroptosis pathway-related proteins, while ELISA was used to detect proinflammatory cytokines interleukin (IL)-6 and IL-8 levels.

Results

Our study discovered that FVP exhibited minimal cytotoxicity to HGFs at the dosages examined. Co-treatment with AGEs and LPS dramatically reduced HGFs cell survival and migratory capacity, while considerably increasing intracellular ROS levels and expression of the cell senescence marker p16. However, the treatment of FVP restore these AGE and LPS-induced adverse effects, as evidenced by the restoration of cell survival and wound healing capacity, ROS production, and decrease the protein expression of p16. FVP inhibits AGEs and LPS-induced cell pyroptosis by lowering pyroptosis markers (apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), NLR family pyrin domain containing 3 (NLRP3), caspase-1, gasdermin D (GSDMD), and IL-1β. Furthermore, FVP dramatically decreased proinflammatory cytokine production levels, including IL-6 and IL-8.

Conclusion

The results of our study demonstrated that FVP had a significant protective effect on human gingival fibroblast damage caused by AGEs and LPS. The addition of FVP can reverse pathological processes such as cellular oxidative stress, poor wound healing, inflammaging, and pyroptosis caused by AGEs and LPS. These findings suggest that FVP could be effective as a therapeutic or adjuvant treatment for DAP.