Study On The Interaction Of Hericium Eryngii Polysaccharide With Nano-silica And The Protective Effect Of Gastric Mucosa

Gastrointestinal health is an important indicator of human health.It is estimated that 10%of the world's population suffer from stomach ulcers,of which 1%will develop into cancer.Gastric ulcers are also listed as pre-cancerous by the WHO.Hericium erinaceus as a well-known medicinal and edible homologous Chinese herbal medicine with stomach protection activity,has been widely used in stomach protection functional foods.However,the relationship between the stomach-protecting activity and structural characteristics of Hericium erinaceus polysaccharide is not clear at present,which limits the application of Hericium erinaceus polysaccharide and the development of related products to a certain extent.Nano-silica has excellent anti-caking property and is often added to solid drinks as food anti-caking agent.Because of the special physical and chemical properties of nano silica,when it is used in functional food,its efficacy and activity may also be affected.However,there are few studies on the application of nano silica as food additive in functional food.In order to promote and apply nano silica effectively,it is necessary to conduct in-depth studies on its biological properties.In this study,two different sources of Hericiinus erinaceus polysaccharides were used as the main raw materials to explore the difference in gastric protective activity,and to explore the activity of its interaction products with nano silica(nSiO₂)and the interaction mechanism.By constructing a rat model of acute gastric mucosal injury with ethanol,the gastric ulcer index and injury inhibition rate were taken as the evaluation indexes by visual observation and histological observation of gastric tissue.Abstract:Hericium erinaceus mycelium polysaccharide(HMP)and Hericium erinaceus fruiting body polysaccharide(HFP)were investigated by detecting the morphological morphology and morphological morphology in vivo.For the macroscopic observation results,the gastric injury index of the model group was44.80,and that of the HMP and HFP groups was 21.75 and 23.75,respectively.For histological observations,the gastric injury index was 2.62 in the model group and 1.25 and1.88 in the HMP and HFP groups,respectively.The results showed that both HMP and HFP had good protective activity against gastric mucosal injury,and HMP had better gastric protective activity than HFP.The interaction products of HMP and HFP with nSiO₂were prepared,which were HMP-nSiO₂and HFP-nSiO₂,respectively.Human gastric mucosal epithelial cells(GES-1)were used as the cell model in vitro,and cell viability and cell migration rate were used as evaluation indexes to investigate the in vitro gastric protective activities of HMP,HFP,HMP-nSiO₂,HFP-nSiO₂and nSiO₂.The cell model induced by ethanol in vitro was established,and the mechanism of gastric protection was preliminarily explored by detecting biochemical indexes such as SOD,MDA,CAT,MPO,GSH and ATP.The results showed that HMP,HFP,HMP-nSiO₂and HFP-nSiO₂could all promote the proliferation and migration of normal GES-1 cells,and the cell migration activity of HMP was significantly better than that of HFP(p<0.05).The proliferation activity of HMP-nSiO₂and HFP-nSiO₂was significantly better than that of HMP and HFP,respectively(p<0.05).In addition,HMP,HFP,HMP-nSiO₂and HFP-nSiO₂all have the effect of preventing and mitigating ethanol damage to GES-1cells.HMP,HFP,HMP-nSiO₂and HFP-nSiO₂play a protective role in gastric mucosa mainly through enhancing CAT enzyme activity to enhance antioxidant capacity and reduce inflammatory response.HMP with better gastric protection activity was selected to further explore the interaction mechanism.First,Vc oxidation and cellulase hydrolysis were used to as two methods to modify polysaccharides,and two different structures of degraded polysaccharides were obtained,named as HMP-Vc and HMP-cellulase.The optimal degradation conditions of polysaccharides by Vc were as follows:Vc concentration is 0.2%,degradation temperature is50?,and degradation time is 2 h;The optimal conditions of polysaccharide enzymolysis by cellulase were as follows:enzymolysis temperature 37?,enzymolysis time 0.5 h,enzyme amount 15%.The interaction products of HMP-Vc and HMP-cellulase with nSiO₂were prepared,which were HMP-Vc-nSiO₂and HMP-cellulase-nSiO₂,respectively.The structures were characterized by monosaccharide composition analysis,fourier transform infrared spectroscopy,scanning electron microscopy,particle size distribution and Congo red assay.The results showed that HMP-Vc and HMP-cellulase had approximately the same characteristic functional groups and monosaccharide composition as HMP,but the dispersion of HMP-Vc and HMP-cellulase in solution was better than that of HMP.Both oxidative degradation of Vc and enzymatic hydrolysis of cellulase can change the apparent properties of HMP,making it smooth and uniform.HMP itself has a compact triple helix structure,while HMP-Vc and HMP-cellulase form random strands in aqueous solution.nSiO₂can interact with polysaccharides with different higher structures through hydrogen bond interaction without affecting the spatial conformation of polysaccharides.The gastric protective activities of HMP-Vc,HMP-cellulase,HMP-Vc-nSiO₂and HMP-cellulase-nSiO₂in vitro were investigated by using in vitro cell model.The results showed that the in vitro gastric protective activities of HMP-Vc and HMP-cellulase were significantly lower than those of HMP.In addition,the presence of nSiO₂does not significantly improve the gastric protective activity of HMP,that is,the gastric protective activity of HMP is closely related to its higher structure.Studies have shown that the gastric protective activity of HMP is closely related to its higher structure.Meanwhile,nSiO₂can interact with polysaccharides through hydrogen bond interaction,and the interaction between nSiO₂and polysaccharides can enhance the gastric protective activity of polysaccharides.