Influence Of Glucose On The Interaction Between Flavonoids And Plasma Proteins

The natural bioactive compounds are believed to be beneficial to human healthand to be promising auxiliary treatment of metabolic disease. It is important to clarifythe metabolism, distribution, and the interaction with biomacrmolecules of thesecompounds, which HSA attracted a lot of interest in diverse fields of biomedicine,pharamacy, nutrition and food science. Herein, polyphenols which are a class ofnatural bioactive compounds were studied experimentally and theoretically on theirinteraction with plasma proteins. The influence of glucose on the interaction betweenflavonoids and plasma proteins was investigated. There are two contents are carriedout.Firstly,the effect of glucose on the binding ability of flavonoids to plasmaproteins is studied. Glucose affected the flavonoid protein interactions dependingupon their structures. Glucose significantly reduced the affinities of HPPs for6-hydroxyflavone by10.72times, slightly weakened the affinities of HPPs forquercetin,7-hydroxyflavone, and kaempferol, and hardly affected the affinities ofHPPs for myricetin, chrysin, and3,7-dihydroxyflavone on the first day. However,glucose obviously enhanced the affinities of HPPs for3-hydroxyflavone, luteolin, andapigenin. Glucose significantly weakened the binding affinities of HPPs for chrysin,kaempferol, quercetin, and myricetin by6.17,7.94,14.12, and112.2times, when keptat37°C under air conditions for14days, and the binding affinities of HPPs for7-hydroxyflavone,luteolin,3,7-dihydroxyflavone,3-hydroxyflavone, and6-hydroxyflavone were slightly decreased by1.35-,1.58-,1.58-,1.9-, and2.4-fold.The binding affinity between apigenin and HPP was hardly influenced. Glucoseweakened the binding affinities of HPPs for hydroxyflavonoids. The differencesbetween log Ka(absence) and log Ka(presence) were bigger for the more lipophilichydroxyflavonoids, and more lipophilic hydroxyflavonoids are easily affected byglucose, when kept at37°C under air condition for14days. These flavonoids withlower hydrogen donor/acceptor numbers prefer to stably interact with HPPs in thepresence of glucose. However, other flavonoids with high hydrogen donor/acceptor numbers (multi-hydroxyl flavonoids) were apt to reduce their affinities with HPPs inthe presence of glucose.Secondly the anti-oxidative assays are including ABTS+radicals and superoxideanion scavenging assays. The results show that: neither HSA nor glucose exists, bothin ABTS+radicals and superoxide anion scavenging assays the reducing power offlavonoids is reduced.