Shrimp waste to shield: Natural peptides combat liver cell stress
image: Protein from shrimp by-products was hydrolyzed by three enzymes (neutral protase, alcalase, and Protamex. Following an initial screening process, five peptides (DYPLVPPYF, HFVPVYEGF, GFPPFTGGPFR, EGYPFNPLL, and RVSDGPWLGR) were selected for their superior free radical scavenging activity, peptide ranking value, and affinity for Kelch-like ECH-associated protein 1 (Keap1) binding. Among the five peptides, HFVPVYEGF and EGYPFNPLL were the most potent anti-oxidative peptide with lower half maximal inhibitory concentration (IC50), and show higher cytoprotective effects on H2O2-damaged HepG2.
Credit: Food Science of Animal Products, Tsinghua University Press
Oxidative stress—caused by an overproduction of reactive oxygen species (ROS)—can lead to cellular damage and is implicated in aging, cancer, and chronic liver diseases. Antioxidants play a crucial role in neutralizing reduce ROS, but concerns over the safety of synthetic antioxidants have prompted a growing interest in natural alternatives. Shrimp processing generates vast amounts of protein-rich waste, much of which is underutilized and environmentally burdensome. Researchers have turned their attention to these by-products as a potential source of natural antioxidant peptides. Due to these pressing environmental and health challenges, further investigation into shrimp waste-derived peptides is both timely and necessary.
A team of scientists from the South China Sea Fisheries Research Institute has discovered antioxidant peptides in shrimp by-products that can protect liver cells from oxidative damage. Published (DOI: 10.26599/FSAP.2025.9240100) in Food Science of Animal Products in January 2025, the study demonstrates that the peptides HFVPVYEGF and EGYPFNPLL significantly mitigate hydrogen peroxide-induced stress in human liver cells (HepG2) cells. Using enzymatic hydrolysis, mass spectrometry, and molecular docking, the researchers outlined a compelling case for upcycling shrimp waste into health-promoting compounds.
The study began by hydrolyzing shrimp by-products using three enzymes—alcalase, neutral protase, and Protamex—to release bioactive peptides. The alcalase-derived hydrolysate exhibited the strongest antioxidant capacity and was further fractionated to isolate peptide-rich extracts. One fraction, labeled A3, showed exceptional radical scavenging activity. Through nano-HPLC-MS/MS, the researchers identified 3,480 peptides, from which five candidates were selected for further analysis based on free radical scavenging scores, peptide rankings, and predicted binding affinity to the Keap1 protein. Among these, HFVPVYEGF and EGYPFNPLL stood out for their low IC50 values and high antioxidant efficacy. Synthesized versions of these peptides were tested on HepG2 cells exposed to H2O2. The results were striking: both peptides reduced ROS levels, increased the activity of antioxidant enzymes (GSH-PX, CAT, SOD), and improved cell viability in a dose-dependent manner. Molecular docking revealed that the peptides bind tightly to Keap1, potentially disrupting the Keap1–Nrf2 interaction, a key regulatory pathway in cellular antioxidant defense. These findings suggest a dual benefit—environmental and biomedical—of repurposing shrimp waste into functional ingredients.
“Our research not only highlights the powerful antioxidant properties of peptides derived from shrimp by-products, but also points to a sustainable way to valorize seafood processing waste,” said Dr. Huan Xiang, co-corresponding author of the study. “By leveraging both biochemical and computational techniques, we were able to identify peptides that offer meaningful protection against oxidative stress in liver cells. These results open the door to further exploration of marine by-products as a functional ingredient in health and nutrition.”
The discovery of antioxidant peptides in shrimp by-products provides a sustainable pathway for developing natural health-promoting agents. These peptides could be incorporated into functional foods, dietary supplements, or skincare products aimed at mitigating oxidative damage. Beyond health applications, this research presents an innovative solution to the environmental problem of seafood waste, adding commercial value to discarded materials. Future research will focus on evaluating the peptides’ bioavailability and efficacy in animal or clinical models, paving the way for real-world applications that blend marine sustainability with biomedical innovation.
The authors are grateful for the financial support from Central Public-interest Scientific Institution Basal Research Fund, South China Sea Fisheries Research Institute, CAFS (2023TD74; 2024RC16) and Guangdong Provincial Special Fund for Modern Agriculture Industry Technology Innovation Teams (2023A04J0090).