A Comparison of Methods for Assessing the Antioxidant Expression in Posidonia oceanica (L.) Delile

Debora Fontanini ^1,2, Fabio Bulleri ¹, Chiara Ravaglioli ¹

⁰Department of Biology, University of Pisa, Via L. Ghini 13, 56126 Pisa, Italy.

Molecules (basel, Switzerland) +

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May 7, 2025

View abstract on PubMed

Summary

Direct assays on seagrass powder offer sensitive measurement of non-enzymatic antioxidants and condensed tannins. This method enhances understanding of plant biochemistry under environmental stress.

Area Of Science

Marine Botany
Plant Biochemistry
Analytical Chemistry

Background

Marine plants like seagrasses produce oxidants when stressed.
Non-enzymatic antioxidants, including polyphenols, combat these harmful oxidants.
Accurate measurement of these compounds is crucial for ecological studies.

Purpose Of The Study

To evaluate methods for measuring antioxidant capacities and condensed tannins in *Posidonia oceanica*.
To compare direct versus sequential polyphenol extraction efficiencies.
To assess the suitability of direct assays on powdered seagrass samples.

Main Methods

Compared direct and sequential polyphenol extraction.
Used a modified HCl-butanol-acetone-iron reagent for condensed tannins assay on leaf flour.
Assayed total antioxidant capacities using ABTS, CUPRAC, and ORAC methods on extracts and powdered samples (QUENCHER).

Main Results

Direct assays demonstrated higher sensitivity than in-solution assays.
Powdered *P. oceanica* samples yielded robust data for antioxidant compound measurement.
Extraction method efficiency varied, highlighting the benefit of direct analysis.

Conclusions

Direct assays on *Posidonia oceanica* powder provide sensitive and in-depth measurement of antioxidant compounds.
This approach allows for effective assessment of biochemical changes in seagrass due to environmental conditions.
The findings support using direct assays for ecological and physiological monitoring of seagrasses.

Keywords:

QUENCHER antioxidant flavonoid polyphenol proanthocyanidin tannin