The effects and mechanism of flavonoid–rePON1 interactions. Structure–activity relationship study

Glabridin, an isoflavan from licorice root, upregulates paraoxonase 2 expression under hyperglycemia and protects it from oxidation

“…Glabridin reached a maximum concentration (87 nmol/L) 1 h after administration, which decreased gradually over 24 h. These findings imply that like other flavonoids, glabridin's beneficial effect might be exerted by a mechanism that is not necessarily related to its antioxidant property. Accumulating evidence indicates that glabridin, like other flavonoids, interacts directly with proteins and modulates their activities .…”

“…Trp‐fluorescence quenching has often been applied to study the binding of small organic molecules to proteins and has recently been employed to study the binding of glabridin to proteins . We applied this procedure to compare the binding affinities of glabridin to the proteins PON2, iNOS, and Mn‐SOD, which were recently discovered to be regulated by glabridin.…”

“…This information indicates that the flavonoid in vivo effects are from much lower concentrations and via mechanisms other than the antioxidant properties observed, in vitro. A growing number of studies have suggested that flavonoids are active due to their noncovalent interaction with proteins (enzymes, receptors, transporters, and transcription factors) . For instance, flavonoids possess a significant binding affinity for serum albumin which is the most abundant protein in the plasma and displays an extraordinary ligand‐binding capacity.…”

Oxidative stress and antioxidant status in beta-thalassemia heterozygotes

“…Additionally, in this disease, a relationship has been observed between increased oxidative stress and decreased levels of the paraoxonase 1 (PON1) protein expressed in the liver and found in blood associated with high-density lipoprotein (HDL) (7) ; this relationship suggests an antioxidant capacity of PON1 (14) . Thus,the decrease in PON1 also reflects a greater susceptibility to the oxidation of low-density lipoproteins (LDL) (2,7) , a known risk factor for cardiovascular disease (15,16) .…”

Effect of water blanching on phenolic compounds, antioxidant activities, enzyme inactivation, microbial reduction, and surface structure of samnamul (Aruncus dioicus var kamtschaticus)

“…Phenolic compounds in samnamul were identified by the UPLC‐Q‐TOF MS and five major compounds including shanzhiside methyl ester, isoquercetin, quercetin 3‐O‐rhamnoside, kaempferol 3‐O‐glucoside and sergeolide were detected. Many studies reported that quercetin and kaempferol derivatives were well‐known as major flavonols with contribution to high antioxidant capacity and reduction potential which attributed to 5‐ and 7‐OH combination as 2, 4‐substituted resorcinol substructure (Rice‐Evans et al , ; Atrahimovich et al , ; Wang et al , ). Similar to this study, Jeong et al () reported that known compounds of samnamul were identified as kaempferol 3‐O‐b‐D‐glucoside, quercetin‐3‐O‐b‐D‐glucopyranoside, kaempferol 3‐O‐b‐D‐(6‐E‐p‐coumarylglucoside) and so on.…”