Purification, structural analysis, and hepatoprotective activity of a polysaccharide from pearl mussel (Anodonta woodiana) meat by-product against alcoholic liver injury.

Pearl mussel (Anodonta woodiana) meat, an underutilized aquaculture by-product, is typically discarded. This study aimed to isolate bioactive polysaccharides from this waste and evaluate their potential as natural hepatoprotective agents against alcoholic liver injury (ALI). Two fractions (AWP-1, AWP-2) were isolated. Based on superior in vitro radical scavenging (DPPH, ABTS, ·OH) and an acidic nature, AWP-2 (23.6 kDa, predominantly glucose) was selected for an in vivo study. In mice with ALI, AWP-2 significantly ameliorated hepatic steatosis and normalized dyslipidemia (reducing TG, TC, LDL-C; elevating HDLC). It lowered the ALT/AST levels and enhanced hepatic antioxidant defenses (SOD, CAT, GSH-Px, GSH) to attenuate oxidative stress. Mechanistically, histological analysis revealed that AWP-2 effectively mitigated alcohol-induced colonic mucosal damage, restoring goblet cells and the mucus layer. This suggests that the hepatoprotective efficacy of AWP-2 may be partially attributed to the preservation of intestinal barrier integrity, thereby linking gut protection to the alleviation of liver injury. This work structurally characterizes a novel shellfish polysaccharide and identifies AWP-2 as a promising candidate for ALI management via its antioxidant properties and potential gut-liver modulation, offering a sustainable strategy for by-product utilization.