Evidence of anti-proliferative activities in blue mussel (Mytilus edulis) by-products

Abstract

Shellfish waste components contain significant levels of high quality protein and are therefore a potential source for biofunctional high-value peptides. The feasibility of applying a pilot scale enzymatic hydrolysis process to whole Mytilus edulis and, by fractionation, recover hydrolysates presenting a biological activity of interest, was evaluated. Fractions were tested on four immortalized cancerous cell lines: A549, BT549, HCT15 and PC3. The 50 kDa fraction, enriched in peptides, presented anti-proliferative activity with all cell lines and results suggest a bioactive molecule synergy within the fraction. At a protein concentration of 44 µg/mL, the 50 kDa fraction induced a mortality of 90% for PC3, 89% for A549, 85% for HCT15 and of 81% for BT549 cell lines. At the low protein concentration of only 11 µg/mL the 50 kDa fraction still entails a cell mortality of 76% for A549 and 87% for PC3 cell lines. The 50 kDa fraction contains 56% of proteins, 3% of lipids and 6% of minerals on a dry weight basis and the lowest levels detected of taurine and methionine and highest levels of threonine, proline and glycine amino acids. The enzymatic hydrolysis process suggests that Mytilus edulis by-products should be viewed as high-valued products with strong potential as anti-proliferative agent and promising active ingredients in functional foods.

Figure 1

Percentage of cell viability (cell growth) obtained for each cancerous cell line after a 72 h exposure with the 50 kDa fraction and both A and B sub-fractions. Results are mean values of four replicates ± SE. (a) A549. (b) BT549. (c) HCT15. (d) PC3. As a positive control, Etoposide at a concentration of 60 μM, displayed a cells viability of 0% for A549 cells, of 0% for BT549 cells, lower than 10% for HCT15 cells and lower than 25% for PC3 cells (for n = 3). The black circles represent the results for the 50 kDa fraction; the empty circles, for the A sub-fraction and the black triangles, for the B sub-fraction.