Peptides derived from snakehead fish (C. striata) albumin demonstrated ACE-inhibiting activity in lab tests, suggesting potential as natural antihypertensive agents.
IC50 of 36.93 μg/mLThe most potent peptide fraction from snakehead fish albumin inhibited ACE at this concentration, comparable to other food-derived ACE inhibitors
What the researchers found
Albumin was isolated from C. striata fish extract using the Cohn Process, yielding 3.8 ± 2.1% in the most albumin-rich fraction (Fraction-5). Two protein bands of approximately 10 and 13 kDa were identified by tricine-SDS PAGE.
ACE inhibition activity increased across fractions, ranging from 7.09% to 22.99%. The highest ACE-inhibiting activity was found in peptides produced by alcalase hydrolysis with molecular size under 3 kDa, achieving an IC50 of 36.93 μg/mL. This was statistically significant compared to non-hydrolyzed fractions, supporting the potential of C. striata albumin-derived peptides as natural antihypertensive agents.
Why it matters
Hypertension affects over a billion people worldwide, and many patients experience side effects from synthetic ACE inhibitors. Identifying natural peptide-based alternatives from food sources like fish could provide new options for blood pressure management with potentially fewer side effects.
How the study worked
Albumin was isolated from C. striata fish extract using the Cohn fractionation process. The protein was then broken down into peptides through enzymatic hydrolysis using alcalase. Proteins were characterized using tricine-SDS PAGE gel electrophoresis, and ACE inhibition was measured using an in vitro assay.
What this study cannot tell us
This was an in vitro study only — ACE inhibition in a test tube does not guarantee the same effect in living organisms. The peptides' stability during digestion, bioavailability, and actual blood pressure-lowering effect in animals or humans remain unknown. The albumin identification was tentative, based on molecular weight rather than definitive sequencing.
How to read the evidence
This is a preclinical in vitro study demonstrating ACE inhibition in lab conditions. No animal or human testing was performed, placing it at an early stage of evidence for any therapeutic claim.
When this study was published
Published in 2023, this is recent research in the active field of food-derived bioactive peptides for cardiovascular health.
The bigger picture
Food-derived bioactive peptides are an expanding area of research, with fish, milk, and plant proteins all being explored as sources of natural ACE inhibitors. This study adds snakehead fish albumin to the growing list of potential sources, contributing to the broader effort to develop functional foods and nutraceuticals for cardiovascular health.
Questions still open
- Do these fish-derived ACE-inhibiting peptides survive digestion and retain activity when consumed orally?
- How do these peptides compare in potency to established food-derived ACE inhibitors from milk or other fish species?
- What are the specific amino acid sequences responsible for the ACE inhibition observed?
Common questions
Can eating snakehead fish lower blood pressure?
What is ACE inhibition and why does it matter for blood pressure?
Read the original research
Peptide derived C. striata albumin as a natural angiotensin-converting enzyme inhibitor.
Heliyon, 9(5), e15958
Citation
Berlian, Guntur; Riani, Catur; Kurniati, Neng Fisheri; Rachmawati, Heni. (2023). Peptide derived C. striata albumin as a natural angiotensin-converting enzyme inhibitor.. Heliyon, 9(5), e15958. https://doi.org/10.1016/j.heliyon.2023.e15958