Study On The Effect Of Natural Pigment On Free Radicals

As an important component of the modern food industry,the development and application of pigment have been widely concerned in recent years.Current studies have shown that many natural pigments are nontoxic,safety and can be used as a free radical scavenger which is beneficial for human health.Free radical as a natural product in the process of cell metabolism can regulate many life processes.However,due to external stimuli will induce abnormal free radical reaction and destroy the dynamic balance of free radical reaction,so it can cause disease.Oxygen free radicals,which are represented by hydroxyl radicals?^·OH?and superoxide free radicals?^·O₂^??,can cause cell senescence,apoptosis and damage to biofilm,protein,nucleic acid and other organizational structures.ONOO^-,a fast combination of nitrous oxide radical?^·NO?and superoxide radical?^·O₂^??,is a kind of cytotoxic substance with strong oxidation and nitrification ability.ONOO^-can also cause damage to the biological macromolecules above,affects the normal process of cell signaling and intracellular energy metabolism process,which lead to a series of diseases such as rheumatoid arthritis,sepsis,Parkinson's disease and cancer eventually.In this study,the effects of several natural pigments on oxygen free radical,hydroxyl radical and peroxynitrite,was investigated.Several methods for evaluating the antioxidant ability of natural pigments were established using Fluorescence Spectroscopy and High Performance Liquid Chromatography–Photodiode Array Detector?HPLC-PDAD?.The interference of the pigment itself in the visible region was avoided at the same time.We selected curcumin,proanthocyanidins,quercetin and naringenin as objects.Using Vitamin C and Vitamin P as positive controls,the effects of this four natural pigments on the inhibition to pyrogallol autoxidation rate,the amount of 2-hydroxy benzoic acid,the amount of dimer-tyrosine and3-nitrotyrosin were investigated by using Ultraviolet spectroscopy,Fluorescence spectroscopy and HPLC-PDAD.It was found that four natural pigments showed different inhibitory effects on free radicals and their damages to biological macromolecules.?1?In the pyrogallol autoxidation experiment,curcumin,quercetin and naringenin were able to scavenge^·O₂^?,which inhibited the colored intermediates of pyrogallol in the process of self-oxidation.The inhibitory ability:Curcumin>Quercetin>Naringin>Vitamin C.The multi-polymer form of proanthocyanidins probably affects its antioxidant activity in this system.?2?In the inhibition of 2-hydroxy benzoic acid experiment,curcumin and procyanidins can remove^·OH,inhibiting the formation of 2-hydroxybenzoic acid.Quercetin and naringenin did not significantly inhibit the formation of2-hydroxybenzoic acid,which may be related to the number of reactive groups in the two structures.vitamin P,as the positive control,firstly,show the effect of promoting,and then show the inhibitory effect,which may be due to low concentrations of vitamin P can produce synergistic effect with vitamin C,which can promote H₂O₂ to generate^·OH.The inhibitory ability:Procyanidins>Curcumin>Vitamin P.?3?In the inhibition of dimer-tyrosine experiment,four natural pigments showed different degrees of anti-oxidative activity.The inhibitory ability:Procyanidins>Curcumin>Naringin>Quercetin>Vitamin C.The IC₅₀ of the four natural pigments inhibited ONOO^-respectively was 4.94?M,1.34?M,16.50?M,8.20?M.?4?In the inhibition of 3-nitrotyrosine experiment,four natural pigments can show different degrees of anti-nitrification activity.The inhibitory ability:Curcumin>Procyanidins>Naringin>Quercetin>Vitamin C The IC₅₀ of the four natural pigments inhibited ONOO^-respectively was 1.10?M,5.18?M,17.90?M,14.66?M.In this study,the abilities of four natural pigments?curcumin,procyanidins,quercetin and naringenin?inhibiting free radical damage biological macromolecules were explored.The inhibitory effect of each pigment on the free radical and its damage process was deduced based on the experimental results and the structure of the substance,as vitamin C and vitamin P as positive controls.It is expected that the inhibiting effect of several systems which can avoid the interference caused by the pigment itself can be initially formed.A basis for developing good anti-oxidation and anti-nitrification activity of natural food and health care products additives was estabilished.At the same time,a theoretical basis to improve the national food additives standards was provided.