Construction,Stability And Antitumor Activity Of Zein-Lentinus Mycelia Polysaccharide Composite Nanoparticles Loaded With Baicalen

Baicalein is an important flavonoid compound,which exists in many edible plants and has good biological activity.However,its application in food and pharmaceutical industry is limited due to its poor water solubility and low bioavailability.Embedding flavonoids in nano delivery system is helpful to overcome these disadvantages.Among them,protein and polysaccharide have excellent biocompatibility and biodegradability.As carrier materials of bioactive material delivery system,it is a research hotspot in recent years.In this paper,zein and Lentinus edodes mycelia polysaccharide were used as carrier materials,Firstly,the interaction mechanism between them were explored,and then zein-Lentinus edodes mycelia polysaccharide nanoparticles loaded with baicalein were constructed to explore their physical stability,bioavailability and antitumor activity.These studies will provide experimental basis for expanding the application range of baicalein and the application of protein-polysaccharide nano delivery system in food and pharmaceutical industry.Firstly,the interaction mechanism between zein and lentinus edodes mycelia polysaccharide was explored by multispectral method.Secondly,zein-lentinus edodes mycelia polysaccharide composite nanoparticles loaded with baicalein were constructed by anti-solvent method,and their stability and bioavailability were tested.Finally,MTT colorimetry,DCFH-DA probe,Hoechst33258 fluorescence staining and Western blot were used to explore the effect and mechanism of composite nanoparticles on inducing apoptosis of Caco-2 cells and analyze its antitumor activity.The following results are obtained:1.Lentinus edodes mycelia polysaccharide and zein could spontaneously form a complex through interaction.Lentinus edodes mycelia polysaccharide could quench the endogenous fluorescence of zein.The quenching mechanism was static quenching.Hydrogen bond and van der Waals force were the main driving forces of their interaction.At 298 K,the quenching rate constant was（3.366±0.17）×10¹³ L mol^-1 s^-1,the binding constant was（17.40±2.54）×10~5 L mol^-1,the binding site was only one.The interaction between Lentinus edodes mycelia polysaccharide and zein changed the microenvironment of zein amino acid residues and induced the change of its conformation.2.Zein-lentinus edodes mycelia polysaccharide composite nanoparticles loaded with baicalein were prepared when the mass ratio of zein to lentinus edodes mycelia polysaccharide was 1:1.The particle size was the smallest（202 nm）,and the PDI was0.124.Compared with zein nanoparticles,the encapsulation efficiency and loading amount of baicalein were increased to（96.15±0.09）%and（7.65±0.06）%.The composite nanoparticles could protect baicalein well during storage,and had good redispersibility and ionic strength stability.At p H 3.0-9.0,the composite nanoparticles could keep steady.But when the p H was less than 3,the solution would accumulate and precipitate.They had good ionic strength stability at low ionic strength（1-100 mm）.In addition,the bioavailability of baicalein was increased to 68.59±3.06%.3.Compared with baicalein,zein-Lentinus edodes mycelia polysaccharide composite nanoparticles loaded with baicalein could significantly reduce the viability of Caco-2 cells,increase the release of lactate dehydrogenase and induce the production of ROS in Caco-2 cells.They could raise regulating the ratio of Bax/Bcl-2 protein,the expression levels of p53,cleaved-caspase-3 and Cyt-C protein,promote the phosphorylation of p38 protein to activate apoptosis and p38 MAPK related signal pathway and induce apoptosis of Caco-2 cells.In conclusion,compared with zein nanoparticles,zein-lentinus edodes mycelia polysaccharide composite nanoparticles improved the encapsulation efficiency of baicalein,had good storage,redispersibility,ionic strength and stability.Moreover,compared with free baicalein,baicalein encapsulated in composite nanoparticles showed better antitumor activity.This study will provide experimental support for the development and utilization of Zein-lentinus edodes mycelia polysaccharide composite nanoparticles,and provide a basis for the comprehensive utilization of baicalein.