Chemical depolymerisation of chondroitin sulfate glycosaminoglycan improves both antioxidant capacity and Fe uptake in a human intestinal Caco-2 cell model

• Published in: Bioactive carbohydrates and dietary fibre Vol. 29; p. 100342
• Main Authors: Wang, Henan, Betti, Mirko
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.05.2023
• Subjects: Acid and alkaline depolymerisation; Antioxidant capacity; Caco-2 cells; Chondroitin sulfate; Ferritin formation; Antioxidant capacity; Chondroitin sulfate; Acid and alkaline depolymerisation; Ferritin formation; Caco-2 cells
• ISSN: 2212-6198; 2212-6198
• DOI: 10.1016/j.bcdf.2022.100342

Chondroitin sulfate (CS) is a high molecular weight sulfated polysaccharide that has been reported to improve joint health. A recent study has demonstrated the ability of enzymatically produced CS-oligosaccharides to improve non-heme iron bioavailability. In this research, CS was chemically hydrolyzed under acid, alkaline, and combined (acid & alkaline) conditions at 60 °C for different times (0–60 h) to understand if the oligosaccharides obtained can improve iron uptake in human intestinal Caco-2 cell model. The acidic hydrolyses produced a collection of desulfated and low molecular weight CS crude oligosaccharides (CS crude oligos), while under alkaline condition a high degree of deacetylation was detected with limited depolymerisation and desulfation. The combined treated CS was first degraded and desulfated in acid solution followed by alkali deacetylation. CS crude oligos produced by the combined treatment possessed the superior antioxidant capacity measured by ferric reducing and DPPH scavenging activities. All chemically hydrolyzed CS samples showed greater (p < 0.05) ferritin formation in Caco-2 cells compared to the negative control, where the greatest ferritin level was achieved by the combined treated CS. The depolymerisation of CS followed by the deacetylation created CS structural changes resulting in the increase of antioxidant and Fe-absorption enhancing capacities. [Display omitted] •Acid hydrolysis caused depolymerisation and desulfation of the CS structure.•Alkali hydrolysis preserved the sulfate groups, but led to CS deacetylation.•The combined method resulted in CS oligos with improved antioxidant capacity.•The Fe uptake by Caco-2 cells are improved by the chemically hydrolyzed CS.