Researchers identified peptides from squid skin that can inhibit ACE — the same enzyme targeted by common blood pressure medications — using mass spectrometry and molecular docking analysis.
Squid skin → ACE inhibitorsEnzymatic digestion of squid skin waste yielded peptides that computationally bind ACE with favorable affinity, suggesting a new marine source for natural blood pressure-lowering ingredients.
What the researchers found
Researchers screened enzymatic hydrolysates from squid (Todarodes pacificus) skin for peptides that inhibit angiotensin-converting enzyme (ACE), a key enzyme in blood pressure regulation. Using mass spectrometry (Nano LC-MS/MS) and computational analysis, they identified candidate peptides with ACE-inhibitory activity. Molecular docking studies confirmed favorable binding interactions between the identified peptides and ACE's active site. The findings establish squid skin as a viable marine source for producing blood pressure-lowering bioactive peptides.
Why it matters
Squid processing generates large amounts of skin waste. Identifying valuable bioactive peptides from this waste stream serves a dual purpose: creating potential natural alternatives to pharmaceutical ACE inhibitors for blood pressure management, and valorizing seafood industry byproducts. Marine-derived ACE-inhibitory peptides are of growing interest because they may offer blood pressure benefits with fewer side effects than synthetic drugs.
The numbers in context
Squid species: Todarodes pacificus · Nano LC-MS/MS peptide identification · In silico screening + molecular docking
How the study worked
Squid skin was enzymatically hydrolyzed and fractionated by molecular weight. Peptide sequences were identified using Nano LC-MS/MS tandem mass spectrometry. ACE-inhibitory potential was predicted through in silico analysis, and molecular docking simulations modeled the interactions between candidate peptides and the ACE enzyme to evaluate binding affinity and mechanism.
Who was studied
Not applicable — in vitro and computational study using squid skin enzymatic hydrolysates
What this study cannot tell us
This is a preliminary screening study using computational (in silico) and in vitro methods only — no animal or human studies were conducted. The abstract appears truncated, so full details of ACE inhibition potency are unclear. Computational predictions of ACE inhibition may not translate to actual biological activity. Bioavailability after oral consumption is unknown — the peptides may be degraded during digestion before reaching the bloodstream.
How to read the evidence
This is a preliminary screening study using computational predictions and in vitro methods. No biological validation in living systems has been performed. The study identifies candidates but does not confirm actual blood pressure-lowering efficacy.
When this study was published
Published in 2025, this is a recent contribution to the active field of marine bioactive peptide discovery. The computational methods used are current, but the findings remain at the earliest stage of development.
The bigger picture
Marine organisms are an increasingly explored source of bioactive peptides, with ACE-inhibitory peptides already identified from fish, shrimp, seaweed, and now squid. The broader goal is developing functional foods or nutraceuticals from seafood processing waste that could help manage mild hypertension without pharmaceutical side effects. This study adds squid skin to the growing inventory of marine peptide sources, though significant development work remains before any practical applications.
Questions still open
- Do the identified squid skin peptides retain their ACE-inhibitory activity after simulated gastrointestinal digestion?
- How does the ACE-inhibitory potency of these squid skin peptides compare to peptides from other marine sources like fish or shrimp?
- Could squid skin peptides be incorporated into functional food products or supplements at concentrations sufficient to affect blood pressure?
Common questions
Can eating squid lower blood pressure?
Why look for blood pressure-lowering peptides in squid skin?
Read the original research
Screening of Potential Angiotensin-Converting Enzyme-Inhibitory Peptides in Squid (Todarodes pacificus) Skin Hydrolysates: Preliminary Study of Its Mechanism of Inhibition.
Marine drugs, 23(2)
Citation
Li, Mingyuan; Liang, Qianqian; Zhang, Yurui; Jiang, Xin; Gu, Yuan; Song, Xin; Wang, Xichang; Shi, Wenzheng. (2025). Screening of Potential Angiotensin-Converting Enzyme-Inhibitory Peptides in Squid (Todarodes pacificus) Skin Hydrolysates: Preliminary Study of Its Mechanism of Inhibition.. Marine drugs, 23(2). https://doi.org/10.3390/md23020081