Effect of daily gavage with a collagen hydrolysate containing calcitonin gene-related peptide (CGRP)-like molecules on plasma CGRP-levels in rats

Siki (Centroscymnus coelolepis) hydrolysates may contain calcitonin gene-related peptide (CGRP)-like molecules. These CGRP-like molecules have attracted attention from the food industry due to their promising applications in the field of functional foods. These CGRP-like molecules were purified and sequenced, and found to show homology to fragments of fish and human collagen. The effect on plasma CGRP-levels of daily gavage with siki hydrolysate containing CGRP-like molecules was further studied in male Wistar rats. The plasma CGRP-levels in rats force fed with the siki hydrolysate were significantly higher than those of the control group. The siki hydrolysate included immunoreactive-CGRP molecules which resisted simulated protein digestion. They were able to cross the intestinal barrier intact and could be responsible for the increase in plasma CGRP levels. This increment in plasma CGRP levels was insufficient to affect body weight or food intake. However, it could lead to other beneficial effects on health.

► CGRP-like molecules were found in a protein hydrolysate of siki and further sequenced.
► These molecules showed significant homology with different regions of collagen.
► Siki hydrolysate increased plasma CGRP-levels in rats after ingestion.
► Some oligopeptides in the hydrolysate showed resistance to gastrointestinal digestion.
► Immunorelated-CGRP molecules resisted gastrointestinal digestion.