Structural Characterization and Antioxidant Activity of Chondroitin Sulfate Derived from Channa argus in Changbai Mountain

Chondroitin sulfate (CS), commonly derived from animal cartilages, is a glycosaminoglycan with various bioactivities. This study employed an alkaline-enzyme method to prepare CS derived from <i>Channa argus</i> (referred to as CCS), using the heads and spines, which are food processing byproducts, as raw materials. Following this, we characterized its structure using HPLC, GPC, FTIR, and NMR and evaluated its antioxidant activity based on a TBHP-induced oxidative stress cell model. Structural analysis revealed that the CCS had a molecular weight of 5.09 kDa and was primarily composed of glucose and galactose units, featuring acetylated glucuronic acid-galactan chains with mixed α/β-glycosidic bonds. In vitro cellular antioxidant assays showed that CCS (80 μg/mL) significantly protected ARPE-19 cells against TBHP-induced oxidative damage by reducing ROS and MDA levels while enhancing the activity of typical antioxidant enzymes (CAT, SOD and GSH-Px). These findings indicate that CS derived from the byproduct of <i>Channa argus</i> processing has notable antioxidant properties and could serve as a promising food supplement for health applications.