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

## TL;DR

This study shows that chondroitin sulfate from a type of fish byproduct has strong antioxidant properties and could be used as a health supplement.

## Contribution

The novel contribution is the structural characterization and antioxidant evaluation of chondroitin sulfate derived from Channa argus byproducts.

## Key findings

- CCS has a molecular weight of 5.09 kDa and is composed of glucose and galactose units.
- CCS significantly reduces oxidative stress in ARPE-19 cells by lowering ROS and MDA levels.
- CCS enhances the activity of antioxidant enzymes CAT, SOD, and GSH-Px.

## Abstract

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 Channa argus (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 Channa argus processing has notable antioxidant properties and could serve as a promising food supplement for health applications.