Evaluation of antioxidant and anti-inflammatory properties of Lacticaseibacillus rhamnosus Ram12-derived exopolysaccharide in a D-galactose-induced liver injury mouse model

We investigated the antioxidant and anti-inflammatory properties of Lacticaseibacillus rhamnosus Ram12-derived EPSRam12 in a D-galactose-induced liver injury mouse model. Initially, EPSRam12 was characterized for its composition, molecular weight, and structural features. It was then administered orally to D-galactose-induced mice (which had received an intraperitoneal injection of D-galactose, 100 mg/kg body weight) at doses of 25 mg/kg (low dose) and 50 mg/kg (high dose) for 45 days. After treatment, biochemical markers, antioxidant status, cytokine levels, and liver inflammatory gene expression were evaluated. The results showed that EPSRam12 was a branched chain heteropolysaccharide comprising mannose, rhamnose, and arabinose monosaccharides with molecular weight of 2.6 million Daltons. EPSRam12, with its unique structural features such as hydroxyl and methyl groups, glycosidic bonds, and functional groups like carboxylates and sulfates, demonstrated promising bioactive properties. Administering EPSRam12 to D-galactose-induced mice resulted in a significant increase in antioxidant enzyme activity and a reduction in oxidative stress indicators. Additionally, it exhibited anti-inflammatory effects by modulating cytokine levels, lowering pro-inflammatory markers, and inhibiting key inflammatory pathways in the liver in a dose-dependent manner. Our findings underscore the potential of EPSRam12 as an effective antioxidant and anti-inflammatory agent, with promising applications in functional foods and pharmaceuticals.