Comparative Analysis of Physicochemical Characteristics of Chondroitin Sulfate from Avian Cartilage: Antioxidant, Anti-inflammatory and Anti-nociceptive Properties

In this study, chondroitin sulfate (CS) was isolated from the sternum cartilage of fully-grown chickens (Gallus gallus) and turkeys (Meleagris gallopavo) at the age of 3 months. The physicochemical characteristics and biological activities of the CS have been determined. Quantitative analyses yielded a CS content averaging 3.87% and 2.78% of dry cartilage for CSGG and CSMG, respectively. The structural characteristics were evaluated by FTIR and NMR spectroscopic methods. The steric exclusion chromatography showed that CSGG and CSMG have a molecular weight with average values of 96,000 Da and 59,000 Da, respectively. The CSs were shown to contain a typical chondroitin core built up of repeating disaccharide units of d-glucuronic acid (GlcA) and N-acetyl-d-galactosamine-6-sulfate (GalNAc-6S) linked by beta 1 -> 3 bonds. Besides, the anti-inflammatory evaluation of CSs in male rats showed a significant inhibition (P<0.05) of edema paw 4 h after subcutaneous injection of 0.1 ml of 1% (w/v) carrageenan solution. The edema inhibition was 81.85% and 79.88% for CSGG and CSMG, respectively. CSs (25 mg/kg) induced a significant decrease in paw withdrawal threshold (56.93 g for CSGG and 63.38 g for CSMG). This pain sensitivity was evaluated by measuring the withdrawal threshold of the paw in response to mechanical stimuli with an electronic von Frey. Our results showed that CS exerted a high total antiradical activity, including the capacity to scavenge DPPH, ABTS radicals, and ferric-reducing power. The overall results showed high antioxidant, anti-inflammatory, and anti-nociceptive activities attributed to the high sulfate content, which made it a promising candidate for an anti-inflammatory drug.