Construction Of Quercetinhohenbuehelia Serotina Polysaccharide Nano-system And Its Digestion And Metabolism Characteristics

Polyphenols are a variety of multi-hydroxyl compounds,with various healthcare activities including antioxidant,blood pressure lowering,anti-diabetic and anti-cancer effects.However,polyphenols ingested by oral intake possesses poor solubility,instability and low absorption rate in human gastrointestinal system.Therefore,solving above problems of polyphenols becomes an urgent scientific topic,which is also confronted by other bioactive substances.Nanotechnology has been widely used in health food and medicine fields.Nano-encapsulation of food functional constituents can increase their solubility,promote their digestion and absorption,reduce their toxic side effect as well as improve their bioavailability.Therefore,the bioactive polyphenol compound quercetin(QC)was selected as the research object in this paper,and Hohenbuehelia serotina polysaccharide(HSP)was chosen as the encapsulation material.Quercetin-Hohenbuehelia serotina polysaccharide nanoparticles(QC-HSP NPs)were constructed by nanotechnology,and investigated their gastrointestinal digestive properties,as well as systematically evaluated their anti-proliferative activity on HeLa cells during gastrointestinal digestion in vitro.QC-HSP NPs were prepared by self-assembly technique,and their physicochemical properties and morphological characteristics were respectively investigated and observed by laser particle size analyzer,XRD,FT-IR,TEM and SEM.The results showed that QC-HSP NPs were formed by QC wrapped in the network cavity of HSP.The intermolecular hydrogen bonding further contributed the formation of QC-HSP NPs.When the QC/HSP mass ratio was 1:32,the prepared QC-HSP NPs had an average particle size of 360.3 nm,a Zeta potential of-38.8 m V,encapsulation efficiency and drug loading rate values of 41.46% and 9.80%.Moreover,QC-HSP NPs possessed the excellent dispersion property and photothermal stability.In vitro and in vivo gastrointestinal digestion models were respectively established to investigate the release characteristics of QC-HSP NPs,and systematically evaluate the effect of QC-HSP NPs on colon fermentation capacity.The results suggested that QC-HSP NPs showed a sustained-release effect during gastrointestinal digestion that could promote the release of QC in small intestine.Moreover,after gastrointestinal digestion and absorption,QC-HSP NPs could significantly improve the organ index and biochemical index of colon,increase the colon length,as well as enhance the water-holding capacity and intestinal motility of colon feces.QC-HSP NPs also obviously increased the contents of short-chain fatty acids in colon,including acetic acid and propionic acid.In order to elucidate the effect of gastrointestinal digestion on the biological activities of QC-HSP NPs,this study was designed to investigate the inhibitory effects of QC-HSP NPs on HeLa cells proliferation in vitro.The results showed that QC-HSP NPs had strong anti-proliferative activities during gastrointestinal digestion,which was more significant than that of free QC.Though analyzing the apoptosis,cell cycle and ROS content of HeLa cells,the results presented that QC-HSP NPs were able to exert their anti-proliferative activities by producing excessive ROS,inducing oxidative damage,arresting cell cycle at G2/M phase,inducing apoptosis.Based on above results,this subject employed self-assembly technology to construct QC-HSP NPs,characterized and analyzed their structural and physicochemical characteristics,and elucidated their digestion and metabolism properties during gastrointestinal digestion,as well as systematically elucidated their anti-proliferative activities during gastrointestinal digestion.This project provides a theoretical research basis for the application of quercetin in functional food field,and has important significance for nano-encapsulation system construction of other bioactive polyphenols.