[Frontiers in Bioscience E3, 1034-1041, June 1, 2011]

Prune melanoidins protect against oxidative stress and endothelial cell death

Anna Maria Posadino1, Annalisa Cossu1, Antonio Piga3, Monica Assunta Madrau3 Alessandra Del Caro3, Maria Colombino1, Bianca Paglietti1, Salvatore Rubino1, Ciro Iaccarino4, Claudia Crosio4, Bastiano Sanna1, Gianfranco Pintus1,2

1 Department of Biomedical Sciences and Centre of Excellence for Biotechnology Development and Biodiversity Research, 2 National Institute of Biostructures and Biosystems, Viale San Pietro 34/B, 07100 Sassari, Italy, 3 Department of Agricultural Environmental Sciences and Food Biotechnology, University of Sassari, Viale Italia, 39, 07100 Sassari, Italy, 4 Department of Physiological, Biochemical and Cellular Science, University of Sassari, Via Muroni 25, 07100 Sassari, Italy

TABLE OF CONTENTS

1. Abstract
2. Introduction
3. Materials and methods
3.1. Chemicals
3.2. Sampling and dehydration
3.3. Determination of HMF, phenolic content and total antioxidant activity.
3.4. Melanoidins extraction
3.5. Measurements of browning index
3.6. Cells culture, treatments, and viability assay
3.7. Determination of cellular redox status
3.8. Measurement of mitochondrial membrane potential
3.9. Statistical analysis
4. Results and discussion
5. Acknowledgement
6. References

1. ABSTRACT

The health-promoting effects of fruit and vegetable consumption are thought to be due to phytochemicals contained in fresh plant material. Whether processed plant foods provide the same benefits as unprocessed ones is an open question. Melanoidins from heat-processed plums (prunes) were isolated and their presence confirmed by hydroxymethylfurfural content and browning index. Oxidative-induced endothelial cell (EC) damage is the trigger for the development of cardiovascular diseases (CVD); therefore the potential protective effect of prune melanoidins on hydrogen peroxide-induced oxidative cell damage was investigated on human endothelial ECV304 cells. Cytoplasmic and mitochondrial redox status was assessed by using the novel, redox-sensitive, ratiometric fluorescent protein sensor (roGFP), while mitochondrial membrane potential (MMP) was investigated with the fluorescent dye, JC-1. Treatment of ECV304 cells with hydrogen peroxide dose-dependently induced both mitochondrial and cytoplasmic oxidation, in addition to MMP dissipation, with ensuing cell death. Pretreatment of ECV304 with prune melanoidins, significantly counteracted and ultimately abolished hydrogen peroxide elicited phenomena, clearly indicating that these polymers protect human EC against oxidative stress.