In Vivo Atlas of Neuroprotective Cyclic Dipeptides Derived from Food Gelatin Using Peptidomics and Feature-Based Molecular Networking

TL;DR

This study identifies neuroprotective cyclic dipeptides from gelatin in the body using advanced analytical methods.

Contribution

A novel strategy combining peptidomics and molecular networking to identify bioactive cyclic dipeptides from gelatin in vivo.

Findings

Cyclodipeptides (CDPs) from gelatin were first identified in serum using feature-based molecular networking.

Twelve proline/hydroxyproline-CDPs showed neuroprotective effects in HT-22 cells, with cyclo-(Hyp-Ala) being the most effective.

CDPs showed prolonged retention in the body and varied distributions in gastrointestinal and serum compartments.

Abstract

Food gelatin is widely used in the food industry, yet
its in vivo active substances remain unclear. This
study proposes
a strategy for in vivo research on donkey-hide gelatin
that integrates peptidomics, feature-based molecular networks (FBMN),
and targeted spatiotemporal metabolomics to address the above issues.
Peptidomics based on database searching revealed a time-dependent
decrease in peptide numbers and an increase in oligopeptide ratios
in the small intestine over 24 h, with oligopeptides increasing from
50 to 100%. FBMN visualization in serum allowed the first identification
of cyclodipeptides (CDPs) originating from gelatin. Targeted metabolomics
detected 35 CDPs in serum, with 12 proline/hydroxyproline-CDPs being
particularly abundant. Spatiotemporal analysis revealed different
distributions of CDPs in the gastrointestinal and serum, and they
showed prolonged retention in vivo. Twelve proline/hydroxyproline-CDPs
displayed neuroprotective effects in HT-22 cells, with cyclo­(Hyp-Ala)
showing the highest efficacy. This study presents a strategy for identifying
exogenous bioactives in complex matrices, applicable to other food
proteins.

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