Antioxidant Effect Of Anthocyanin Nanoliposomes On Gastrointestinal Cells

Anthocyanins have many biological functions,such as inhibiting and scavenging the production of free radicals,activating the antioxidant enzyme system,and inhibiting the metastasis and proliferation of cancer cells.Nanoliposomes are widely used as carriers for encapsulation of active substances,because they have the membrane structure of phospholipid bilayer,so they are often used as drug carriers to target cells.As an active material carrier,nanoliposomes have the advantages of slow release,easyly uptake by cells,stable action,passive targeting and no adverse reactions.At present,liposomes are widely used as drug carriers,and nanoliposomes are ideal carriers for liposome activity.Bioactive substances embedded in nanoliposomes can effectively prolong the time of action and increase its efficacy.In this study,various methods were combined to observe the form,pathway and distribution of C3G nanoliposomes into Caco-2 cells.Meanwhile,the changes of C3G nanoliposomes after entering cells and the action mode and site of antioxidant activity were investigated.The research content of this topic mainly includes the following aspects:（1）Through single factor test and response surface optimization test,it was determined that the optimal preparation process conditions were:anthocyanin concentration:0.21 mg/mL,lipid/bile ratio:2.83:1 mg/mg,pH（PBS）:6.75,and the theoretical optimal encapsulation rate was 67.22%.In view of the objective factors of the actual experimental operation,the preparation process was selected as anthocyanin concentration:0.2 mg/mL,lipophilic ratio:2.8:1 mg/mg,and pH（PBS）:6.75.Under the optimized process,the encapsulation rate,particle size and multi-dispersion coefficient were measured as 67.36%,228.30 nm and 0.183,respectively.（2）As the storage time of anthocyanin nanoliposomes increased,anthocyanin nanoliposomes were gradually oxidized,leading to a certain degree of leakage of anthocyanin encapsulated in its interior.The particle size of nanoliposomes changed little but gradually increased.In simulated gastric intestinal fluid,the anthocyanin nanoliposomes gradually released anthocyanin,and the leakage rate was relatively low and stable within 0-1 h.Metal ions have little effect on anthocyanin nanoliposomes and no significant difference.（3）Caco-2 and GES-1 cells were used as research objects to observe the form and pathway of C3G nanoliposomes entering cells and the distribution after entering cells.It was found that phlorizin and phloreti could significantly inhibit the transport of anthocyanin,while both phlorizin and phloreti acted as inhibitors of SGLT1 and GLUT2,suggesting that both SGLT1 and GLUT2 were involved in the absorption of anthocyanin in the small intestine.Caveolae pathway is not involved in liposome endocytosis,and endocytosis mediated by macrocytosis and clathrin is the main pathway of anthocyanin nanoliposomes.（4）The GES-1 cells were incubated for 24 h with a concentration of H₂O₂ of800μmol/L to establish the oxidative induced damage model of H₂O₂.The apoptosis and cycle of cells treated with different concentrations of anthocyanins and anthocyanins nanoliposomes were studied,and it was found that the growth of Caco-2 cells was inhibited by the treatment of anthocyanins and anthocyanins nanoliposomes,while the growth of GES-1 cells was less affected by the treatment.At the same time,it was found that anthocyanins and anthocyanin nanoliposome at200μg/mL had the best effect on reducing intracellular ROS.