Characterization of acid-soluble collagen from peanut worm (Siphonosoma australe) and its inhibitory activity of cyclooxygenase-2

The aim of this study was to determine the effect of acetic acid extraction time on the physicochemical characteristics of peanut worm collagen and its ability to inhibit cyclooxygenase-2 (COX-2). The peanut worms were subjected to extraction using 0.5 M acetic acid for varying durations, followed by analysis for various physicochemical properties, including yield, protein content, pH, viscosity, molecular weight, amino acid composition, FTIR, and COX-2 inhibitory activity. The results showed that 72 h of extraction time was optimal for collagen production. The peanut worm collagen yields, protein, and pH were 3.55 ± 0.20, 85.58 ± 0.10, and 3.61, respectively. The relative viscosity of collagen decreased with increased temperature by 51.35. Collagen consists of α and β chains with high levels of amino acids such as glutamic acid, arginine, and aspartic acid. SDS-PAGE analysis revealed that peanut worm collagen contained type I collagen. FTIR confirmed the collagen’s triple-helical structure. The COX-2 inhibitor assay showed that collagen inhibited the COX-2 enzyme by 41.12 ± 0.58 (IC50 = 59.9 μg mL–1). Therefore, this peanut worm collagen could serve as a potential substitute for terrestrial mammalian collagen as an ingredient in food, cosmetics, and other industries. In addition, peanut worm collagen can be used as a nutraceutical and medicine to prevent and treat inflammatory diseases.