A novel galactoglucan from Ganoderma lucidum ameliorates ethanol-induced gastric ulcers by modulating FAK-MAPK signaling pathway.

Gastric ulcer (GU) is a prevalent gastrointestinal disorder that significantly impacts patients' quality of life. Current treatments, including proton pump inhibitors and H2 receptor antagonists, often present limitations such as adverse side effects and incomplete healing, highlighting the urgent need for new therapeutic agents. Ganoderma lucidum polysaccharide peptides (GL-PP) have gained attention for their potential gastroprotective properties. Notably, we characterized a novel GL-PP named GL-PPQ3, assessing its efficacy in alleviating GUs using an ethanol-induced GU mouse. Our findings indicated that GL-PPQ3 is a hyperbranched galactoglucan with a molecular weight of 41.08 kDa, predominantly composed of glucose and galactose. Comprehensive analysis, including methylation and one-dimensional and two-dimensional nuclear magnetic resonance (NMR), elucidated its structural composition, revealing the presence of 1,6-α-D-Galp, 1,2,6-α-D-Galp, 1,6-β-D-Glcp, 1,3,6-β-D-Glcp, and 1,4-β-D-Glcp residues. X-ray diffraction (XRD) confirmed a predominantly amorphous structure and scanning electron microscopy (SEM) displayed aggregated spherical formations. Mechanistically, GL-PPQ3 exhibited its Gastroprotective effects through the regulation of the FAK-mediated MAPK signaling pathway. This study underscores the therapeutic potential of GL-PPQ3 as a promising candidate for GU treatment, paving the way for developing novel functional agents derived from natural sources.