A Comparative Study of the Inhibitory Effect of Some Flavonoids and a Conjugate of Taxifolin with Glyoxylic Acid on the Oxidative Burst of Neutrophils

Abstract

During the storage, processing, and digestion of flavonoid-rich foods and beverages, a condensation of flavonoids with toxic carbonyl compounds occurs. The effect of the resulting products on cells remains largely unknown. The aim of the present study was to evaluate the effects of quercetin, taxifolin, catechin, eriodictyol, hesperetin, naringenin, and a condensation product of taxifolin with glyoxylic acid on the oxidative burst of neutrophils. It was found that the flavonoids and the condensation product inhibited the total production of ROS. Flavonoids decreased both the intra and extracellular ROS production. The condensation product had no effect on intracellular ROS production but effectively inhibited the extracellular production of ROS. Thus, the condensation of flavonoids with toxic carbonyl compounds may lead to the formation of compounds exhibiting potent inhibitory effects on the oxidative burst of neutrophils. The data also suggest that, during these reactions, the influence of a fraction of flavonoids and their polyphenolic derivatives on cellular functions may change. On the whole, the results of the study provide a better understanding of the effects of polyphenols on human health. In addition, these results reveal the structure–activity relationship of these polyphenols and may be useful in a search for new therapeutic agents against diseases associated with oxidative stress.

Enemies or Allies? Hormetic and Apparent Non-Dose-Dependent Effects of Natural Bioactive Antioxidants in the Treatment of Inflammation

“…Linear or monotonic correlation occurs in the first interaction of a chemical species with a biochemical target molecule, but biological media are typically complex and give rise to nonlinear responses [44]. This is because the antioxidant compound can interact with multiple molecules and systems in the body, which can lead to complex effects [45][46][47][48][49][50][51]. In Figure 3, two representations of this type of nonlinear dose-response curve are labelled as "b" and "c".…”

“…Different authors have tried to interpret the hormetic effects of different compounds. In some cases, well-documented opposing effects on cell proliferation and mitochondrial redox metabolism can explain biphasic dose-response curves [44][45][46][47][48][49][50][51]. This has allowed modeling of some biphasic dose-response curves, which is possible when the conditions of a limited number of biochemical reactions that generate opposing effects in individuals are known [46][47][48][49][50][51].…”