Antioxidant Activity And Molecular Regulate With Molecular Control Of Catechin Nanoliposomes Based On The Cell Model

Catechin has good antioxidant activity,which belongs to the high efficient natural antioxidants,but its poor stability,rapid metabolism of the body and other reasons leading to its antioxidant performance can not be efficient play,restricting the depth of catechin research and development.Nanoliposomes because of its unique small size effect,quantum effect and other characteristics,so that in the processing and after entering the body with better stability and higher biological activity and other advantages.The vitro free radical oxidative damage model is based on the study of intracellular oxidation of cells and can better predict the antioxidant activity of the substance in vivo.In this study,the optimal technological process of preparation of catechin nanoliposomes was studied,evaluate its characterization,stability and in vitro antioxidant activity,observe its role in Caco-2 cells,study its antioxidant activity in Caco-2 cells,explore its molecular regulation of Caco-2 cells.The results are as follows:?1?Through the single factor and response surface experiments,the optimum formulation was as follows:phosphatidylcholine-to-cholesterol ratio of 3.13:1 mg/mg,rotational evaporation speed of 31.12 r/min,catechin concentration of 3.82 mg/mL.Taking the experimental conditions into account,the preparation process was set to phosphatidylcholine-to-cholesterol ratio of 3:1 mg/mg,rotary evaporation speed of 30r/min,catechins concentration of 3.80 mg/m L,in this prescription,the encapsulation efficiency was 76.21%,and the reproducibility was good;the particle size was 221.40nm;polydispersity index PDI was 0.177;under scanning electron microscopy,catechin nanoliposomes were evenly distributed,structural integrity,for spherical particles,with the phenomenon of reunion.?2?With the storage time increases,the lipid of catechin nanoliposomes gradually oxidized,the particle size changed little but would gradually increase,in0⁵ d relatively stable;in the simulated gastrointestinal fluid within 0¹ h leakage rate was low,in 1² h,the leakage rate greatly increased,in 2⁵ h,the leakage rate gradually increased and stabilized;metal ions on its little effect and change relatively gentle.In general,the influence level of metal ions was classified as sodium citrate<calcium citrate<potassium sorbate;the vitro antioxidant activity experiments showed that in the storage process,catechins,which were protected by nanoliposomes,were not destroyed by extensive oxidization in the external environment,and the antioxidant activity of catechins was protected by nanoliposomes.?3?The model of H₂O₂ induced by 0.198 mmol/L H₂O₂ acting on Caco-2 cells for 24 h was determined;through the test experiment of catechin nanoliposomes cytotoxicity,the maximum concentration of 0.025 mg/mL was obtained in the subsequent experiment;by examining the changes of Caco-2 cells under the action of catechin nanoliposomes,it was found that catechin nanoliposomes and catechins were inhibited in a concentration-dependent manner on SOD activity and GSH content in H₂O₂,the content of MDA and NO increased,and the effect of catechin nanoliposomes group was better.?4?By using transmission electron microscopy?TEM?,it was observed that the catechin nanoliposomes were found in the cytoplasm after entering Caco-2 cells.By Western Blot method and grayscale analysis method,the experiments showed that catechin nanoliposomes have protective effects on H₂O₂-oxidized cells and stronger than the same concentration of catechins.By in situ molecular hybridization and gray value calculation,it was suggested that catechin nanoliposomes could increase the expression of SOD mRNA in H₂O₂-oxidized cells and inhibit the expression of NOX mRNA in H₂O₂-oxidized cells,and the effect was better than that of catechins group.From the content of the block,catechin nanoliposomes inhibited the oxidative damage of Caco-2 cells induced by H₂O₂,which was related to the increase of SOD mRNA expression and protein expression,inhibition of NOX mRNA expression and protein expression.A comprehensive and specific regulatory mechanism still needs further inquiry and remains to be confirmed.