Flavonoids are a group of polyphenols with important bioactivity capacities and there is a growing interest on the role of these compounds in tolerance to environmental factors.
In this work, we show that 7 of the 13 flavonoids studied have an ability to reduce cytochrome c (Cyt c) similar or higher than ascorbate: the flavonols quercetin, kaempferol and myricetin, flavanol epigallocatechin-gallate, anthocyanidins cyanidin and malvidin, and the flavone luteolin. Different biophysical techniques showed that flavonoids did not interfere with Cyt c binding to cardiolipin (CL)/phosphatidylcholine vesicles, but attenuated the CL-induced loss of Cyt c Soret band, pointing out a stabilization of the protein in the complex. Moreover, several flavonoids also inhibited the pro-apoptotic CL-induced peroxidase activity of Cyt c, indicating the modulation of Cyt c signaling at the mitochondria is a probable mechanism behind the biological activities of flavonoids.
Authors: Lagoa R, Samhan-Arias AK, Gutierrez-Merino C