Production and Fractionation of Rocky Shore Crab (Grapsus albacarinous) Protein Hydrolysate by Ultrafiltration Membrane: Assessment of Antioxidant and Cytotoxic Activities

Abstract

ABSTRACT Bioactive peptides from marine protein sources hold tremendous promise as potent antioxidant agents with plausible anticancer activity. Herein, the antioxidant activities of crab protein hydrolysate and its ultrafiltration fractions at different molecular weights (>30 kDa,10–30 kDa,3–10 kD and<3 kDa) using various methods (DPPH, ABTS and FRAP assay) were investigated carefully. The results showed that although all peptide fractions from the crab hydrolysate showed some activity, the low molecular weight fractions (3–10 kDa and <3 kDa) generated the highest antioxidant activity, with a high content of hydrophobic amino acids (48.87% for 3–10 and 46.26% for <3 kDa). Interestingly, both low molecular weight peptide fractions showed a remarkable cytotoxic effect against the MCF-7 cells, while the 3–10 kDa peptide fraction proved to be more effective. Phase-contrast microscopy of treated MCF7 cells with the 3–10 peptide fraction confirmed various morphological alterations and cell damages. Overall, the study suggested that the low molecular weight peptide fractions of rocky shore crab Grapsus albolineatus hydrolysate could be considered as a natural antioxidant candidate in the prevention of cancer by reducing free radicals production, as well as an anticancer agent in cancer treatment by cytotoxic effect on cancer cells.