Anti-obesity Mechanisms Of Mongolian Medicine Digda On Obese Mice Via Gastrointestial Barrier Function And Microflor Regulation

Objective: To study the effects of Mongolian medicine Lomatogonium rotatum(LZH)on weight loss and gastrointestinal nutrient absorption in obese mice induced by high fat diet,and to clarify its relationship with intestinal microflora regulation.Ussing Chamber and LC-MS were used to explore the absorption mechanism of LZH in the gastrointestinal tract.Method: Kunming male mice were given high fat diet to establish obesity model.After 8 weeks of feeding,except normal diet group(normal diet group,ND),obesity model mice(the body weight is 20% greater than the ND group mice)were randomly divided into high fat diet group,LZH high dose group(LZH1.8g/kg),LZH medium dose group(LZH0.9g/kg),LZH low dose group(LZH0.18g/kg)and positive control group(Orlistat,0.048g/kg).The body weight and food intake of mice were recorded every week.After 9 weeks of LZH treatment,Lee`s index,visceral fat weight,serum total cholesterol(CHO),triglyceride(TG),high-density lipoprotein cholesterol(HDL-C)and low density lipoprotein cholesterol(LDL-C)concentrations,liver weight and liver function index aspertate aminotransferase(AST)and alanine aminotransferase,(ALT)were measured;Animal feces were collected from the ceacum and used for 16 S r DNA Amplicon sequencing to detect the gutmicrobiota composition.Small intestinal tissues were harvested to study the absorption of nutrient FD4 in the Ussing Chamber instrument.LCMS method was used to detect the chemical components of LZH extract.Tissues from the stomach,small intestine and colon of normal mice were selected and time points with relatively high absorption of LZH extract were screened by Using chamber and LC-MS.Bitter taste receptor blocker gallein was used to identify the potential mechanism related to the nutrients absorption and bitter taste receptor functions.LC-MS was used to analyze the content of absorption components,and the bitter absorption mechanism of LZH was preliminarily investigated.Results: The in vivo results showed that LZH low,medium and high dose of LZH could significantly reduce the body weight of obese mice(P<0.01).Low,medium and high dose of LZH significantly decreased the Lee’s index of rats(P<0.05).LZH at low,medium and high doses significantly reduced the food intake of obese mice(P<0.001).The results of measurement of visceral fat weight showed that the periintestinal fat,perirenal fat and periepididymal fat were significantly decreased by low,medium and high doses of LZH(P<0.05).The biomedical analysis results showed that LZH extract high-dose group significantly decreased serum CHO,TG,HDL-C and LDL-C of obese mice,and increased the serum HDL-C level(P<0.05).Also,LZH low dose significantly decreased(P<0.05)the serum ALT level,while the AST was not significantly affected.As for the absorption of nutrient FD4 in the small intestine of mice at different time points,the permeability of FD4 in the HFD group was significantly increased at 90 min,while that in the LZH medium and low dose group tended to be normal(P<0.05).16 S r DNA Amplicon sequencing technology was used to detect the feces in the ceacum of mice.The results showed that the number of microbial species decreased after administration of LZH and the microbial diversity caused by high fat diet was decreased.LZH group could reduce the increase of Firmicutes and Proteobacteria caused by high fat diet,and increase Bacteroidetes and Firmicutes/Bacteroidetes ratio.At the level of genus classification,LZH can reduce Clostridium Xl Va,Roseburia and Parabacteroides significantly,and increase Prevotella,Oscillibacter and Desulfovibrio.The results showed that the concentrations of alternariolmethylether,bellidifolin,choline,hesperetin,swertiamarin,α,α-Trehalose,bellidifolin and sweroside were higher than those of other extracts from LZH by LC-MS.The results of in vitro screening of LZH extract in different gastrointestinal fragments and different time points showed that the absorption of LZH extract in small intestine fragments at 30 min,60min,90 min and 120 min time points were relatively high.The results showed that the permeability of swertiamarin,sweroside and hymecromone were affected by the bitter receptor inhibitor gallein.In addition,the absorption of LZH extract in the small intestine of normal mice and obese mice was compared.The results showed that the absorption of LZH extract in obese mice was significantly reduced.Conclusion: The main chemical constituents of the extract of LZH are swertiamarin,hesperetin,choline,bellidifolin and sweroside.Moreover,the extract can reduce the bodyweight,feed intake,Lee’s index,liver index,adipose tissue weight,blood CHO,TG and ALT level,and significantly increase the serum HDL level.Its weight loss may be caused by improving intestinal barrier injury and adjusting intestinal microflora disorder caused by high fat diet,such as decreasing the relative abundance of Firmicutes and Proteobacteria and F/B ratio,and increasing Bacteroidetes relative abundance.It was also preliminarily confirmed that the absorption of bitter components in LZH was related to the bitter receptor inhibitor gallein in the small intestine.The results of this study laid a foundation for further clarifying the relationship between bitter components of LZH and the intestinal microbiota composition.