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Aglianico Grape Pomace Extract Reduces Cardiac Pacemaker Activity by Decreasing Hyperpolarization-Activated Current
Roberta De Zio1, Maira Certini1, Eugenia Pignataro1
1Department of Biosciences, Biotechnology and Environment, University of Bari Aldo Moro, 70125 Bari, Italy.
Life (Basel, Switzerland)
|May 27, 2026
Summary
Grape pomace extract (GPE) from Aglianico grapes slows heart rate by reducing the funny current (If). This effect occurs independently of cyclic AMP (cAMP) and is conserved in both mammalian cells and fruit fly hearts.
Area of Science:
- Cardiovascular Physiology
- Electrophysiology
- Pharmacology
Background:
- Grape pomace extract (GPE) from Vitis vinifera L. cv. Aglianico contains polyphenols with known cardioprotective effects.
- The direct electrophysiological impact of GPE on cardiac spontaneous activity remains uninvestigated.
Purpose of the Study:
- To investigate the chronotropic effects of Aglianico GPE on cardiac cells and organisms.
- To elucidate the underlying electrophysiological mechanisms of GPE's action on heart rate.
Main Methods:
- Whole-cell patch-clamp and intracellular Ca2+ imaging in HL-1 cardiomyocytes.
- Optical recording of the Drosophila melanogaster larval heart tube.
- ELISA for cyclic AMP (cAMP) level quantification.
Main Results:
- GPE (25 µg/mL, 48h) reduced spontaneous action potential frequency in HL-1 cells, prolonging diastolic depolarization without altering action potential morphology or Ca2+ homeostasis.
- GPE decreased hyperpolarization-activated funny current (If) density without affecting its voltage dependence or cAMP sensitivity.
- Dietary GPE significantly reduced heart rate in Drosophila larvae, indicating a cAMP-independent effect.
Conclusions:
- Aglianico GPE exerts a negative chronotropic effect by reducing functional If density via a cAMP-independent mechanism.
- This mechanism of action is conserved across phylogenetically distant species, suggesting a fundamental role in regulating cardiac rhythm.
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