Abstract
Previous studies have shown that extracts of shark cartilage induce a cytokine response in human leukocytes, but the nature of the bioactive component(s) is unknown. Extracts treated with proteases lost 80% of their cytokine-inducing property, suggesting that the active component(s) was likely a complex protein. The aim of the present study was to determine the nature of the bioactive molecule(s). Solid phase extraction followed by ion exchange chromatography and electrophoretic separation were used to partially purify a bioactive preparation from commercial shark cartilage that has been identified as a small glycoprotein. LC–MS analysis yielded peptides with 100% molecular identity with collagen type II, alpha I protein from the lesser spotted catshark, Scyliorhinus canicula. The implications for the consumption of shark cartilage as a dietary supplement are discussed given the presence of collagen type II, alpha 1 protein in extracts.
► An immunomodulatory glycoprotein was isolated from shark cartilage extracts. ► The active component stimulated human leukocytes to produce high levels of TNF-α. ► It was identified as collagen type II, alpha 1 protein of Scyliorhinus canicula. ► Collagen type II, alpha 1 is a highly conserved protein of vertebrate cartilage. ► As an immune modulator ColIIa 1 could modulate cellular response following trauma.
