Antioxidative activity of the olive oil constituent hydroxy-1-aryl-isochromans in cells and cell-free systems.
BACKGROUND
Hydroxy-1-aryl-isochromans (HAIC) are newly emerging natural polyphenolic antioxidants, enriched in extravirgin olive oil, whose antioxidative potency was only scarcely characterized using cell-free systems and cells.


METHODS
We characterized the activity of HAIC to inactivate reactive oxygen species (ROS) generated by the xanthine/xanthine oxidase system, mitochondria (rat brain) and neural cells. ROS levels were estimated using ROS-sensitive probes, such as Amplex Red, MitoSOXRED.


RESULTS
HAIC (with 2, 3 or 4 hydroxyl substituents) effectively scavenge ROS released from mitochondria. EC50 values estimated with mitochondria and submitochondrial particles were around 20 microM. Moreover, in PC12 and cultured neural primary cells, HAIC buffered cytosolic ROS. Although HAIC permeate biological membranes, HAIC fail to buffer matrix ROS in isolated mitochondria. We show that hydrogen peroxide was effectively abolished by HAIC, whereas the production of superoxide was not affected.


CONCLUSIONS
HAIC exert high antioxidative activity to reduce hydrogen peroxide. The antioxidative activity of HAIC is comparable with that of the stilbene-like, polyphenolic resveratrol, but much higher than that of trolox, N-acetylcysteine or melatonin.


CONCLUSIONS
Unlike resveratrol, HAIC do not impair mitochondrial ATP synthesis or Ca2+ retention by mitochondria. Thus, HAIC have the decisive advantage to be potent antioxidants with no detrimental side effects on mitochondrial functions.
Institut für Biochemie und Zellbiologie, Otto-von-Guericke-Universität Magdeburg, Leipziger Str. 44, Medizinische Fakultät, 39120 Magdeburg, Germany. peter.schoenfeld@med.ovgu.de
Peter
P
Schönfeld
Nicol
N
Kruska
Georg
G
Reiser
D000818:Animals; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D002474:Cell-Free System / Q000187:drug effects / Q000378:metabolism; D002478:Cells, Cultured; D004353:Drug Evaluation, Preclinical; D005419:Flavonoids / Q000009:adverse effects / Q000737:chemistry / Q000494:pharmacology*; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D008954:Models, Biological; D000069463:Olive Oil; D018384:Oxidative Stress / Q000187:drug effects; D016716:PC12 Cells; D010636:Phenols / Q000009:adverse effects / Q000737:chemistry / Q000494:pharmacology*; D010938:Plant Oils / Q000737:chemistry* / Q000494:pharmacology; D059808:Polyphenols; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D000077185:Resveratrol; D013267:Stilbenes / Q000737:chemistry / Q000494:pharmacology; D014969:Xanthine Oxidase / Q000378:metabolism
D000975:Antioxidants; D005419:Flavonoids; D000069463:Olive Oil; D010636:Phenols; D010938:Plant Oils; D059808:Polyphenols; D017382:Reactive Oxygen Species; D013267:Stilbenes; D014969:Xanthine Oxidase; D000077185:Resveratrol