Title:Antioxidant Capacities of Flavones and Benefits in Oxidative-Stress Related Diseases
Volume: 15
Issue: 2
Author(s): Marcelo D. Catarino, Jorge M. Alves-Silva, Olivia R. Pereira and Susana M. Cardoso
Affiliation:
Keywords:
Antioxidant activity, Coronary heart diseases, Diabetes, Flavones, Neurodegenerative disorders, Oxidative stressrelated
diseases, Structure-activity relationship.
Abstract: Flavonoids, a group of secondary metabolites widely distributed in the plant kingdom, have been
acknowledged for their interesting medicinal properties. Among them, natural flavones, as well as some of
their synthetic derivatives, have been shown to exhibit several biological activities, including antioxidant,
anti-inflammatory, antitumor, anti-allergic, neuroprotective, cardioprotective and antimicrobial. The antioxidant properties
of flavones allow them to demonstrate potential application as preventive and attenuating agents in oxidative stress, i.e., a
biological condition that is closely associated to aging process and several diseases. Some flavones interfere in distinct
oxidative-stress related events by directly reducing the levels of intracellular free radicals (hydroxyl, superoxide and nitric
oxide) and/or of reactive species (e.g. hydrogen peroxide, peroxynitrite and hypochlorous acid) thus preventing their amplification
and the consequent damage of other biomolecules such as lipids, proteins and DNA. Flavones can also hinder
the activity of central free radical-producing enzymes, such as xanthine oxidase and nicotinamide adenine dinucleotide
phosphate oxidase (NADPH-oxidase) or inducible nitric oxide synthase (iNOS) and can even modulate the intracellular
levels of pro-oxidant and/or antioxidant enzymes. The evaluation of flavones antioxidant ability has been extensively determined
in chemical or biological in vitro models, but in vivo therapy with individual flavones or with flavones-enriched
extracts has also been reported. The present manuscript revises relevant studies focusing the preventive effects of flavones
on stress-related diseases, namely the neurological and cardiovascular diseases, and diabetes and its associated complications.