Study Of Interaction And Antioxidant-activity Relationships Between Natural Flavonoids And Serum Protein

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 theinteraction with biomacrmolecules of thesecompounds, which has attracted a lot of interest in diverse fields of biomedicine,pharamacy, nutrition and food science. Study of Interaction and Antioxidant-ActivityRelationships between Natural lfavonoids and Serum protein was investigated.There are two contents are carried out.Firstly, The human plasma protein binding of water soluble flavonoids in thepeels of five spices of citrus fruits were studied by ultrafiltration combined with HPLC.The flavonids were extracted separately by hot and cold water, and higher totalflavonoid contents were detected in the former extracts than the latter ones. All theextracts showed significant scavenging abilities to both ABTS and DPPH free radicals,which indicated the health benefits of the water extracts of citrus fruits peels. ForDPPH radical, the IC50values of hot extract followed as NO^MO<LE<LO<PO, whilethe rank was N0<PO<LE^MO<LO for ABTS radical. The HPLC results revealed thatthe kinds and contents of the flavonoids detected in the extracts were differentamong the species. The plasma binding rates decreased with the increasingconcentrations of flavonoids, arid the flavonids having plenty hydroxy I groups onboth A ring and B ring of the molecular skeleton had relative higher plasma bingdingrates. In addition, the plasma binding rates of flavonoids with saturated C3-C4bonddecreased significantly with the increasing concentrations.Secondly，taking advantage of several radical scavenging assays involving DPPHfree radical, ABTS free radical，and superoxide anion radical，and ferric reducingpower assay, it was found that plasma proteins masked the free radical scavengingpotential of polyphenols and hardly impacted the antioxidant power of polyphenols.Compared with the plasma proteins from healthy, the plasma proteins from type2diabetes obvious/y weaken the masking effect on the free radical scavenging capacityof polyphenolsb. It was concluded that polyphenols in di，abeticsblood are tend to e interacted with free radical and can not be efficiently delivered to other tissues, whichdiminishes the benefits of free radical scavenging potential of polyphenols.