Exopolysaccharide from endophytic fungi of Cinnamomum burmannii leaves: structural characterization and hepatoprotective effects

Exopolysaccharides derived from endophytic fungi inhabiting medicinal plants are promising bioactive agents. Herein, a neutral exopolysaccharide termed DEPS was extracted and purified from an endophytic fungus isolated from Cinnamomum burmannii leaves, with a yield of 51.12 %. Structural analysis by HPGPC, UV, FTIR, NMR, and SEM revealed that DEPS is primarily composed of glucose, with minor amounts of mannose and galactose, and features →6)-α- d -Glcp-(1→ and →4)-α- d -Glcp-(1→ linkages. Functionally, DEPS exhibited a superior moisture-retention rate of 26.4 %, comparable to sodium alginate and glycerol, and showed moderate antioxidant activity. In vitro , DEPS effectively suppressed IL-6 expression in macrophages by approximately twofold, and inhibited zebrafish neutrophil migration by 50 %. In an acetaminophen (APAP)-induced liver injury model, DEPS treatment significantly alleviated hepatic damage by decreasing necrosis area from 55.2 % to 24.1 %, and reducing IL-1β expression from 273.3 % to 118.6 %. Additionally, DEPS promoted an anti-inflammatory environment through enhanced IL-10 expression and reduced TNF-α levels. These findings highlight DEPS as a structurally unique, multifunctional polysaccharide with hepatoprotective, anti-inflammatory, and antioxidant potential for food, pharmaceutical, and cosmetic applications.