Secoisolariciresinol Diglucoside

Hyperuricemia (HUA) is a metabolic disorder with an increasing prevalence rate in last decade. Although secoisolariciresinol diglucoside (SDG) from flaxseed was reported to have anti-inflammatory effects, its role and action mechanism in alleviating HUA remain unclear. This study investigated the effect of SDG on reducing uric acid (UA) in mice with HUA induced by potassium oxonate (PO) and hypoxanthine. The results showed that oral administration of SDG at 300 mg/kg significantly reduced UA levels by 75.37 ± 4.05 % and suppressed hepatic xanthine oxidase (XOD) gene expression by 50.99 ± 2.72 % compared to the model group, accompanied by amelioration of structural abnormalities in the liver, kidneys, and intestines. This urate-lowering effect was associated with renal transporter modulation: ABCG2 protein expression increased by 67.72 ± 11.22 %, while OAT1 expression surged by 175.90 ± 18.34 %. Meanwhile, the levels of GLUT9, URAT1 were downregulated by 19.12 ± 1.47 % and 63.73 ± 2.54 %, respectively. Intestinal ABCG2 expression was further upregulated by 62.21 ± 1.16 %, and GLUT9 mRNA levels decreased by 84.15 ± 4.12 %, collectively improving UA excretory dysfunction. Besides, SDG alleviated UA-induced intestinal injury, preserved epithelial integrity, and upregulated the expression of tight junction proteins (including ZO-1 and occludin) through the inhibition of the TLR4/ NF-κB signaling pathway, thereby contributing to the protection of intestinal immune barrier. SDG ameliorated UA-disrupted purine metabolism and bile acid secretion by increasing the abundance of beneficial bacteria (e.g., Alistipes, Prevotellaceae_UCG-001, and Ruminococcus) and decreasing the abundance of pathogenic genera (e.g., Parabacteroides, Bacteroides, and Desulfovibio). Hence, SDG showed its potential to become a natural functional ingredient for HUA amelioration.

This study was carried out to determine the influence of conventional oven drying (CDG), spray drying (SDG), and freeze drying (FDG) on the physicochemical, powder, functional, and gelling properties of turkey skin gelatin. SDG (12%) and FDG (13%) have lower yields than CDG (15%). SDG and FDG also had lower bulk density but higher Hausner ratio and Carr index values compared to CDG. However, spray and freeze‐drying increased the expansion and stability of the gelatin foam, which also exhibited improved solution clarity and lightness compared to CDG. FDG (370.86 g) and SDG (365.02 g) had higher bloom strength values than CDG (321.55 g). The gelation temperatures of 23.8, 27.79, and 25.23°C and the melting temperatures of 29.55, 32.79, and 30.84°C were determined for CDG, SDG, and FDG, respectively. These results indicated that the temperature‐dependent gel network formation tendency and melting resistance of SDG and FDG were enhanced, possibly due to their higher high molecular weight peptide fractions. Consistently, SDG and FDG had higher gelation kinetics (kgel) than CDG. The effect of the short time of spray drying and the low temperature of lyophilization on the formation of a less degraded protein structure compared to CDG was confirmed by SDS‐PAGE and FTIR. The spray and freeze‐drying methods may be suitable for the production of turkey skin gelatin for techno‐functionally enhanced food and pharmaceutical applications.

This research has potential applications in the food industry, primarily to demonstrate turkey skin gelatin as an alternative to bovine gelatin and that superior functional properties can be achieved under freeze‐drying conditions.