Flavonoids as Natural Modulators of Mitochondrial Potassium Channel

Flavonoids belong to a vast group of polyphenolic compounds that are widely distributed in all foods of plant origin. They exhibit a large variety of biological properties. Interest in health benefits of flavonoids has increased due to their potent antioxidant and free-radical scavenging activities. The biological activity, bioavailability and low toxicity set broad prospects of the usage of some of these substances as potential therapeutics for a number of human diseases. Some flavonoids have also been shown to be cardioprotective. Although the antioxidant effect of flavonoids has been long thought to be a crucial factor accounting for cellular cardioprotection, mitochondrial pathways (including mitochondrial ion channels) are presently emerging potential targets for a specific pharmacological action of some flavonoids in the anti-ischemic strategies.The detailed research describing a direct interaction of flavonoids with mitochondrial potassium channels is lacking. Therefore, the scientific aim of the these studies is the description of the regulation of the mitoBKCa and mitoKATP channels by selected flavonoids and functional consequences of this regulation.Our studies with mitoplasts isolated from primary human dermal fibroblast cells suggest that application of 10 μM naringenin leads to an increase in mitoBKCa channel activity. Statistical analysis of these results showed that opening probability of the channel decreased from 0.95 in the control conditions (100 μM Ca2+) to 0.06 at low calcium level (1 μM Ca2+) and increased to 0.81 after application of naringenin. Also, it has been observed that activity of the mitoKATP channel increases after application of 10 µM naringenin.This study was supported by a grant MERIS PBS1/B8/1/2012 from the National Centre of Research and Development, Poland and partially by The Nencki Institute of Experimental Biology, Poland.