Study On The Mechanisms Of Celastrol In Treating Colon Diseases Using Metabolomics

At present incidence of Inflammatory Bowel Disease(IBD)continues to rise,and IBD has the risk of developing colon cancer.Available drugs suffer from various adverse reactions,leading to the urgency to investigate and develop new IBD therapy.Celastrol,extracted from Trypterygium wilfordii Hook F,is a triterpenoid monomer with apparent intervention effect on IBD and colon cancer,but its mechanism is unclear.Metabolomics characterizes the overall and dynamic changes of endogenous small molecule metabolites in biological systems in response to pathophysiological stimuli or genetic modification,which helps with systematic investigation and elucidation of diseases pathogenesis and mechanisms of action of new drugs.Therefore,in this study,we take metabolomics as a guideline to study the mechanism of celastrol on IBD and colon cancer and associated pathway.Firstly,based on ulcerative colitis mice model of IBD induced by dextran sulfate sodium(DSS),we found celastrol has apparent intervention effect on colitis mice,as revealed by restoring the weight of mice,relieving diarrhea and rectal bleeding,improving the colon length,reducing inflammatory tissue damage and decreasing the TNF? levels.Then,based on untarged metabolomics of UPLC-Q-TOF-MS,we investigated the possible mechanism of colitis with celastrol intervention.We found celastrol can play anti-colitis role by regulating amino acid metabolism,lipid metabolism and nucleic acid metabolism.Secondly,in view of the important role of lipid metabolites in ulcerative colitis,we have further developed a lipidomics study of celastrol on ulcerative colitis.The results shown the levels of unsaturated Lysophosphatidylcholine(LPC)in the model group were down-regulated and its levels were all restored after celastrol treatment.LPC can be synthesized by fatty acids,so we further to analyse the corresponding fatty acid levels by GC-MS methods.Then,we determined the expression levels of enzyme SCD1 in the unsaturated fatty acid synthetic metabolic pathway by qPCR analysis.The results shown the level of SCD1 in the colitis group was significantly decreased,and celastrol can restore the expression of SCD1,which further confirmed the results of lipidomics.Thirdly,in order to investigate the mechanism of celastrol on colon cancer,we treated HCT116 colon cancer cells with celastrol to carry out untargeted metabolomics study.We found celastrol could interfere with amino acid metabolism,carnitine metabolism,etc,and combined with quantitative analysis of UPLC-MS/MS,we found tryptophan and its metabolite kynurenine levels was significantly altered.Then we determined the levels of protein expression of Indoleamine 2,3-Dioxygenase(IDO)catalysing tryptophan along the kynurenine pathway(KP),and the results shown celastrol can significantly down-regulate the expression of IDO.In summary,based on metabolomics,we investigated the mechanism of celastrol on colon disease in this study.The results shown celastrol could play anti-colitis role by regulating amino acid metabolism,lipid metabolism,nucleic acid metabolism and directly or indirectly restoring the SCD1 expression.Based on the results of HCT116 cells,celastrol can significantly down-regulate the expression of IDO.The mechanisms of celastrol on IBD and colon cancer cells have similarities and differences,which remains to be further studied.This study can provide scientific basis for further development of celastrol.