The Effect And Mechanism Of Mirabilite On Promoting Bile Acid Production In Hypercholesterolemia Mice

Background:Hypercholesterolemia is a metabolic disease characterized by elevated serum cholesterol(mainly elevated low-density lipoprotein cholesterol),and it is also a main risk factor of cardiovascular and cerebrovascular diseases.Studies have shown that if intervention is not performed at the early stage of the disease,persistently elevated low-density lipoprotein cholesterol will accelerate the process of atherosclerosis,which will eventually lead to the occurrence of coronary heart disease and cerebral infarction.Thus,the prevention and treatment of hypercholesterolemia has become an important public health and safety issue.At present,the treatment of hypercholesterolemia is mainly composed of three types: statins,bile acid sequestrants and PCSK9 inhibitors.However,they cause side effects such as muscle pain,rhabdomyolysis,and severe gastrointestinal reactions are prohibitive for many patients.Therefore,it is extremely urgent to find a drug for the prevention and treatment of hypercholesterolemia with small side effects and relatively low price.Bile acids are the important regulators of hepatoenteric circulation.Excessive bile acids can accelerate diarrhea.In recent years,with the application and development of traditional Chinese medicine resources,more and more traditional Chinese medicine has been found to have new curative effects that are little known.Among them,Mirabilite,a representative drug of laxatives,has been well-known to the public for its effects of "moistening intestines and laxative,moisturizing dryness and softening".Whether Mirabilite causes diarrhea by causing excessive production of bile acids remains unclear.In this article,we will construct hypercholesterolemia model mice with a highcholesterol diet,discussed the effect and molecular mechanism of mirabilite on hypercholesterolemia,provide a theoretical basis for the clinical treatment of hypercholesterolemia and Chinese medicine screening and development.Objective:Observe the effect of mirabilite on hypercholesterolemia caused by high cholesterol diet.From the perspectives of cholesterol metabolism,bile acid metabolism,intestinal microbiota,etc.The effect and mechanism of mirabilite on cholesterol conversion to bile acid in hypercholesterolemic mice were discussedMethods:1.C57BL/6J male mice were used as the research object,and the HCD diet was used to construct a hypercholesterolemia mouse model.2.Mice fed with normal diet served as the Control group(CON).Successfully modeled mice were randomly divided into 4 groups,namely the model group(MOD),the low-dose Mirabilite group(MOD-LM),the middledose Mirabilite group(MOD-LM)and the high-dose Mirabilite(MOD-HM)The CON group and the MOD group were given distilled water by gavage,and the other three groups were given different doses of Mirabilite solution by gavage.The materials were taken after 3 weeks of gavage.3.Measure serum and tissue biochemical indexes through the kit.H&E staining was used for pathological analysis.Discover potential mechanisms of action through transcriptome sequencing.Use q PCR,WB,and other molecular biological techniques to detect cholesterol and bile acid metabolism-related genes.16 S r DNA was used to sequence the contents of the cecum.Results:1.The mice model were successfully constructed: compared with CON group,after 4 weeks of HCD induction,serum TC content in the MOD group increased by ≥2 times,which was in line with the characteristics of hypercholesterolemia.2.The cholesterol conversion and bile acid synthesis genes were upregulated after Mirabilite gavage,and the expression of hepatic LDL-R increased.3.Mirabilite reduced the expression of TRB3 in the liver,and Akt increased significantly after administration.4.Mirabilite reduced the activity of FGF15 in the ileum,reduces the expression of KLB,inhibit JNK signaling and improve the transcription of CYP7A1.Conclusion:This study preliminarily proves that Mirabilite can reduce the serum total cholesterol level of diet-induced hypercholesterolemia model mice and promote the conversion of liver cholesterol to bile acids.Its mechanism of action may be to improve insulin resistance and reduce the receptor KLB on the liver cell membrane surface,inhibits the phosphorylation of the downstream target gene JNK,promotes the increase of CYP7A1 transcription,and ultimately accelerate the conversion of cholesterol to bile acid in the liver.