Compound Enzyme-Assisted Extraction and Characterization of Trigonella foenum-graecum L. Polysaccharides and Their Ameliorative Effects on MAFLD.

Trigonella foenum-graecum L. seed polysaccharides (FSP) belong to a very important species of biological macromolecules with prebiotic activity, which are the basic substances that have broad application potential in food and pharmaceutical fields. However, systematic studies focusing on the compound enzyme-assisted extraction of FSP and their hepatoprotective effects remain limited. This study aimed to optimize the compound enzyme-assisted extraction of FSP, analyze the structural features of deproteinized FSP (DFSP), and evaluate its therapeutic potential against metabolism-associated fatty liver disease (MAFLD). The results showed that the optimal extraction conditions were an enzymatic hydrolysis temperature of 50°C, an enzymatic hydrolysis pH of 5.3, an enzymatic hydrolysis time of 1.9 h, and a liquid-to-solid ratio of 23:1 mL g-1, under which the polysaccharide yield reached 24.88% ± 0.15%. The molecular weight distribution of fenugreek seed polysaccharides was 7157.46, 2785.65, and 642.61 Da, and they were mainly composed of mannose and galactose. In vivo experiments indicated that DFSP exerted a liver-protective effect on MAFLD mice, accompanied by improvements in lipid metabolic parameters, antioxidant capacity, and inflammatory responses. Therefore, this study provides a scientific basis for further investigations into the fine structure and potential hepatoprotective effects of DFSP.