Chemophysical Characterization of Carotenoproteins From Crustacean Shell Waste for Pharmaceutical Applications.

Commercial crustacean species represent some of the most economically valuable fishery products; however, their full potential remains underexploited due to the routine disposal of shellfish waste, which is rich in high-value bioactive compounds. Among these, carotenoid pigments have garnered increasing interest for their antioxidant and anti-inflammatory properties. In this study, we investigate the potential of recovering bioactive compounds from the shells of the European lobster (Homarus gammarus Linnaeus, 1758) and the Atlantic blue crab (Callinectes sapidus Rathbun, 1896), with a particular focus on carotenoprotein complexes with promising applications in the pharmaceutical and cosmetic industries. We adopted a computational approach integrating protein contact networks, molecular docking, and molecular dynamics simulations to characterize the structural and functional properties of crustacean carotenoproteins as nanocarriers for astaxanthin. Then, we explored in silico the antioxidant activity of astaxanthin, as claimed by many studies. Specifically, we applied the computational analyses to the interaction between astaxanthin and Kelch-like ECH-associated protein 1 (Keap1-DC domain), a key regulator of the Nrf2 signaling pathway involved in oxidative stress. Results suggest that astaxanthin would compete with Nrf2 at the Keap1-DC domain, then promote Nrf2 induction and activate the antioxidant cellular machinery. These findings are supported by preliminary experimental evidence and highlight the potential of astaxanthin extracted from crustacean shell waste as a bioactive agent, with possible applications in diseases associated with oxidative stress, including cancer. Further preclinical and clinical in vivo studies are needed to validate astaxanthin and the carotenoprotein-astaxanthin complex for efficacy and safety, with potential relevance for oncology.