The Anti-ulcerative Colitis Activity And Potential Mechanism Of Action Of Sweet Tea(Lithocarpus Litseifolius(Hance) Chun)

Lithocarpus litseifolius(Hance)Chun,also known as Lithocarpus polystachyus Rehd and sweet tea,which is rich in flavonoids,terpenoids,and other compounds,exhibiting antioxidant,anti-inflammatory,and hypoglycemic activities.Ulcerative colitis(UC)belongs to inflammatory bowel disease(IBD),and its pathogenesis is not very clear,easy to relapse.Long-term drug treatment can cause drug resistance and may even lead to colon cancer.Therefore,it is essential to develop products of natural origin as an alternative to drug therapy.Previous studies indicate that natural products,such as flavonoids,can alleviate or ameliorate UC.In this study,UHPLC-ESI-Q-TOF-MS/MS was used to identify the phytochemical components in the sweet tea extract(STE).Subsequently,human normal intestinal epithelial cell NCM460 was used to establish an inflammatory model induced by LPS to investigate the anti-inflammatory activity of STE and its main flavonoids.Furthermore,the DSS-induced UC mice model was established to explore the anti-ulcerative colitis activity of STE in vivo.Finally,network pharmacology and molecular docking were used to explore the potential antiulcerative colitis mechanism of STE,which can provide theoretical basis for the development of functional foods using the sweet tea as raw materials.Key findings include:(1)The compounds in STE showed good responses in both positive and negative ion modes,and 17 compounds with relatively high intensities in the negative ion mode were further confirmed,including catechin,procyanidin B1,myricetin 3-O-β-D-glucoside,isoquercitrin,luteolin,3-hydroxy phlorizin,naringin 7-O-hexoside,phlorizin,homoplantaginin,trilobatin,6 "-O-acetylorizin,phloretin 2’-O-(2"-O-acetylglucoside),phloretin,hispidulin,tricin,etc.Among them,the peak area of trilobatin,phlorizin,phloretin,and isoquercitrin were the largest,and they were the main flavonoid components of STE.(2)STE and its major flavonoids,including trilobatin,phlorizin,phloretin,and iso quercitrin,could inhibit the release of ROS and NO,reduce the release of pro-inflam matory factors IL-6 and TNF-α in NCM460 inflammatory cells model induced by LP S.(3)STE could alleviate the weight loss,the pathologic symptoms of UC mice,improve the shortening of colon and the integrity of colon mucosa,reduce cell infiltration,increase the number of goblet cells,and increase the activities of SOD and GSH,reduce the content of MDA,IL-6,IL-1β and TNF-α,increase the content of IL-10,which were contributed to the anti-colitis effect of STE in vivo.(4)Network pharmacology showed that the bioactive ingredients of STE were trilobatin,phlorizin,phloretin,isoquercitrin,catechin,tricin,hispidulin,and naringin 7-O-hexoside.There were 293 potential targets of these bioactive ingredients in STE,1417 targets of UC,and 106 common targets.According to PPI network and Compounds-Targets-Pathway net work analysis,the key targets were IL6,TNF,VEGFA,EGFR,MMP9,PTGS2,ABL,ESR1,HIF1A,and SRC.According to GO and KEGG enrichment analysis,the key signaling pathways included PI3K-AKT signaling pathway,C-type lectin receptor signaling pathway,TNF signaling pathway,MAPK signaling pathway,and many other pathways,which are related to inflammation,immune,antioxidation,and so on.It is suggested that STE may play a critical role in improving UC through regulation of inflammation,immunity,anti-oxidation,and repairing intestinal barrier.Molecular docking results showed that the 8 bioactive ingredients of STE could bind well to the 10 key targets.According to the docking score,trilobatin,phlorizin,and isoquercitrin may be the effective components of STE to improve UC,and TNF,MMP9,and PTGS2 were the core targets.In conclusion,trilobatin,phlorizin,isoquercitrin,and other components of STE can improve UC mainly through the regulation of PI3K-AKT,TNF,and other signaling pathways that are related to inflammation,immunity,anti-oxidation,and intestinal barrier.