Structure, anti-tumor activity, and potential anti-tumor mechanism of a fungus polysaccharide from Fomes officinalis

In our ongoing process of discovering bioactive macromolecules, a homogeneous polysaccharide (FOP80-1) was first purified from Fomes officinalis. FOP80-1 with molecular weight of 4560 Da was mainly composed of →3)-d-Galp-(1→, →4)-β-d-Manp-(1→, →6)-α-d-Glcp-(1→, →3,6)-d-Glcp-(1→, and t--d-Glcp. Besides the structure features, the anti-tumor activity and potential mechanism of FOP80-1 were also investigated. The cellular and zebrafish experiments revealed that FOP80-1 inhibited tumor proliferation, invasion, and metastasis by increasing ROS, arresting cell cycle, inducing apoptosis, and suppressing angiogenesis. Corresponding to the inhibition of angiogenesis, the surface plasmon resonance (SPR) experiments revealed that FOP80-1 had good affinity with VEGF, a crucial protein to regulate angiogenesis. Molecular docking indicated that FOP80-1 could interact with the protein VEGF.